Last data update: Aug 15, 2025. (Total: 49733 publications since 2009)
| Records 1-29 (of 29 Records) |
| Query Trace: Fix N [original query] |
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| A pilot comparison of fixatives for hookworm real-time polymerase chain reaction
Bradbury R , Inagaki K , Singh G , Agana U , Patterson K , Malloch L , Rodriguez E , Qvarnstrom Y , Hobbs CV . Am J Trop Med Hyg 2022 108 (2) 335-339 Polymerase chain reaction (PCR) is increasingly used in the diagnosis of soil-transmitted helminth infections. Despite this, few studies have evaluated the impact of different fecal fixatives on the outcome of fecal helminth qPCR analysis, and none have evaluated the effect of commercial parasitology fixatives commonly used in diagnostic laboratories. We fixed dog feces containing Ancylostoma spp. hookworm eggs in zinc polyvinyl alcohol (Zn-PVA) and Total-Fix, and with 70% ethanol (EtOH) as a control. DNA was extracted at timepoints 11, 33, 64, and 94 days and subjected to Ancylostoma spp. quantitative PCR (qPCR). A linear regression model was created to assess the effect of preservative types on the temporal change of qPCR quantification cycle number (Cq) values, accounting for variances among individual animals. Fixation in 70% EtOH least affected Cq values over 94 days. Total-Fix preservation yielded a higher Cq overall, but there was no significant difference compared with 70% EtOH fixation. Fixation in Zn-PVA resulted in significantly (P < 0.001) higher Cq values than 70% EtOH after only 33 days and loss of amplification at 64 days. Consistent with other helminth fixation studies, 70% EtOH performed well in preserving hookworm DNA over 94 days. Total-Fix provided a comparable alternative for qPCR analysis for hookworm. Fixation in Zn-PVA resulted in loss of detectable hookworm DNA at 64 days, as determined by qPCR. |
| Stability of specimens for use in the Centers for Disease Control and Prevention assays for factor VIII and IX inhibitors
Payne AB , Boylan B , Niemeyer G , Werner B , Driggers J , Miller CH , Bean CJ . Res Pract Thromb Haemost 2022 6 (7) The Centers for Disease Control and Prevention (CDC) Nijmegen‐Bethesda Assay (NBA)1 is a modification of traditional methods2., 3. for measurement of factor VIII (FVIII) and factor IX (FIX) inhibitors that includes a 30‐minute preanalytical heat treatment (PHT) step to remove endogenous and infused FVIII or FIX. Specimens for inhibitor tests using PHT thus do not require the stringent conditions needed to maintain clotting factors during shipping and storage, as we have previously documented by split‐sample analysis showing that results of the CDC‐modified NBA on specimens shipped cold correlated well with those of frozen specimens.1 |
| Fecal shedding of two novel live attenuated oral poliovirus type 2 vaccines candidates by healthy bOPV/IPV-vaccinated infants: two randomized clinical trials.
Gast C , Bandyopadhyay AS , Sáez-Llorens X , De Leon T , DeAntonio R , Jimeno J , Aguirre G , McDuffie LM , Coffee E , Mathis DL , Oberste MS , Weldon WC , Konopka-Anstadt JL , Modlin J , Bachtiar NS , Fix A , Konz J , Clemens R , Costa Clemens SA , Rüttimann R . J Infect Dis 2022 226 (5) 852-861
BACKGROUND: Primary intestinal immunity through viral replication of live oral vaccine is key to interrupt poliovirus transmission. We assessed viral fecal shedding from infants administered Sabin monovalent poliovirus type 2 vaccine (mOPV2) or low and high doses of 2 novel OPV2 (nOPV2) vaccine candidates. METHODS: In 2 randomized clinical trials in Panama, a control mOPV2 study (October 2015 to April 2016) and nOPV2 study (September 2018 to October 2019), 18-week-old infants vaccinated with bivalent oral poliovirus vaccine/inactivated poliovirus vaccine received 1 or 2 study vaccinations 28 days apart. Stools were assessed for poliovirus RNA by polymerase chain reaction (PCR) and live virus by culture for 28 days postvaccination. RESULTS: Shedding data were available from 621 initially reverse-transcription PCR-negative infants (91 mOPV2, 265 nOPV2-c1, 265 nOPV2-c2 recipients). Seven days after dose 1, 64.3% of mOPV2 recipients and 31.3%-48.5% of nOPV2 recipients across groups shed infectious type 2 virus. Respective rates 7 days after dose 2 decreased to 33.3% and 12.9%-22.7%, showing induction of intestinal immunity. Shedding of both nOPV2 candidates ceased at similar or faster rates than mOPV2. CONCLUSIONS: Viral shedding of either nOPV candidate was similar or decreased relative to mOPV2, and all vaccines showed indications that the vaccine virus was replicating sufficiently to induce primary intestinal mucosal immunity. |
| Evaluating stability of attenuated Sabin and two novel type 2 oral poliovirus vaccines in children.
Wahid R , Mercer L , Gast C , De Leon T , Sáez-Llorens X , Fix A , Macadam A , Stephens L , Chumakov K , Smits SL , Murreddu M , Konopka-Anstadt JL , Steven Oberste M , Burns CC , Andino R , Bachtiar NS , Tritama E , Bandyopadhyay AS , Aguirre G , Rüttimann R , Konz JO . NPJ Vaccines 2022 7 (1) 19
Novel oral poliovirus vaccine type 2 (nOPV2) is being developed to reduce the rare occurrence of disease and outbreaks associated with the genetic instability of the Sabin vaccine strains. Children aged 1 to 5 years were enrolled in two related clinical studies to assess safety, immunogenicity, shedding rates and properties of the shed virus following vaccination with nOPV2 (two candidates) versus traditional Sabin OPV type 2 (mOPV2). The anticipated pattern of reversion and increased virulence was observed for shed Sabin-2 virus, as assessed using a mouse model of poliovirus neurovirulence. In contrast, there were significantly reduced odds of mouse paralysis for shed virus for both nOPV2 candidates when compared to shed Sabin-2 virus. Next-generation sequencing of shed viral genomes was consistent with and further supportive of the observed neurovirulence associated with shed Sabin-2 virus, as well as the reduced reversion to virulence of shed candidate viruses. While shed Sabin-2 showed anticipated A481G reversion in the primary attenuation site in domain V in the 5' untranslated region to be associated with increased mouse paralysis, the stabilized domain V in the candidate viruses did not show polymorphisms consistent with reversion to neurovirulence. The available data from a key target age group for outbreak response confirm the superior genetic and phenotypic stability of shed nOPV2 strains compared to shed Sabin-2 and suggest that nOPV2 should be associated with less paralytic disease and potentially a lower risk of seeding new outbreaks. |
| The Clinical Genetics of Hemophilia B (Factor IX Deficiency)
Miller CH . Appl Clin Genet 2021 14 445-454 Hemophilia B (HB) is a bleeding disorder caused by deficiency of or defect in blood coagulation factor IX (FIX) inherited in an X-linked manner. It results from one of over 1000 known pathogenic variants in the FIX gene, F9; missense and frameshift changes predominate. Although primarily males are affected with HB, heterozygous females may have excessive bleeding due to random or non-random X chromosome inactivation; in addition, homozygous, compound heterozygous, and hemizygous females have been reported. Somatic and germinal mosaicism for F9 variants has been observed. Development of antibodies to FIX treatment products (inhibitors) is rare and related to the type of causative variant present. Treatment is with products produced by recombinant DNA technology, and gene therapy is in clinical trials. Genetic counseling with up-to-date information is warranted for heterozygotes, potential heterozygotes, and men and women affected with HB. |
| Women and girls with haemophilia receiving care at specialized haemophilia treatment centres in the United States
Miller CH , Soucie JM , Byams VR , Payne AB , Sidonio RF Jr , Buckner TW , Bean CJ . Haemophilia 2021 27 (6) 1037-1044 INTRODUCTION: Females may have haemophilia with the same factor VIII (FVIII) or factor IX (FIX) levels as affected males. Characterization of females with haemophilia would be useful for health care planning to meet their unique needs. Federally-funded haemophilia treatment centres (HTCs) in the United States contribute data on all individuals with bleeding disorders receiving care to the Population Profile (HTC PP) component of the Community Counts Public Health Surveillance of Bleeding Disorders project. AIMS: To estimate the number of females with haemophilia receiving care at HTCs in the United States and compare their characteristics with those of males with haemophilia. METHODS: HTC PP data collected on people receiving care at an HTC from January 2012 through September 2020 with haemophilia A and B were evaluated by sex for demographic and clinical characteristics. RESULTS: A factor level < 40% was reported for 23,196 males (97.8%) and 1667 females (47.6%) attending HTCs; 51 (.48%) severe, 79 (1.4%) moderate, and 1537 (17.9%) mild haemophilia patients were female. Females were older, more often White, and less often non-Hispanic than males. Females were less likely to have history of HIV or HCV infection, even among those with severe disease, but twice as likely to have infection status unknown. Females with mild haemophilia were more often uninsured than males. CONCLUSIONS: Females with severe or moderate haemophilia are uncommon, even in specialized care centres; however, almost one in five patients with mild haemophilia was female, indicating needs for specialized care based on factor level and history for affected females. |
| Global, regional, and national estimates and trends in stillbirths from 2000 to 2019: a systematic assessment
Hug L , You D , Blencowe H , Mishra A , Wang Z , Fix MJ , Wakefield J , Moran AC , Gaigbe-Togbe V , Suzuki E , Blau DM , Cousens S , Creanga A , Croft T , Hill K , Joseph KS , Maswime S , McClure EM , Pattinson R , Pedersen J , Smith LK , Zeitlin J , Alkema L . Lancet 2021 398 (10302) 772-785
BACKGROUND: Stillbirths are a major public health issue and a sensitive marker of the quality of care around pregnancy and birth. The UN Global Strategy for Women's, Children's and Adolescents' Health (2016-30) and the Every Newborn Action Plan (led by UNICEF and WHO) call for an end to preventable stillbirths. A first step to prevent stillbirths is obtaining standardised measurement of stillbirth rates across countries. We estimated stillbirth rates and their trends for 195 countries from 2000 to 2019 and assessed progress over time. METHODS: For a systematic assessment, we created a dataset of 2833 country-year datapoints from 171 countries relevant to stillbirth rates, including data from registration and health information systems, household-based surveys, and population-based studies. After data quality assessment and exclusions, we used 1531 datapoints to estimate country-specific stillbirth rates for 195 countries from 2000 to 2019 using a Bayesian hierarchical temporal sparse regression model, according to a definition of stillbirth of at least 28 weeks' gestational age. Our model combined covariates with a temporal smoothing process such that estimates were informed by data for country-periods with high quality data, while being based on covariates for country-periods with little or no data on stillbirth rates. Bias and additional uncertainty associated with observations based on alternative stillbirth definitions and source types, and observations that were subject to non-sampling errors, were included in the model. We compared the estimated stillbirth rates and trends to previously reported mortality estimates in children younger than 5 years. FINDINGS: Globally in 2019, an estimated 2·0 million babies (90% uncertainty interval [UI] 1·9-2·2) were stillborn at 28 weeks or more of gestation, with a global stillbirth rate of 13·9 stillbirths (90% UI 13·5-15·4) per 1000 total births. Stillbirth rates in 2019 varied widely across regions, from 22·8 stillbirths (19·8-27·7) per 1000 total births in west and central Africa to 2·9 (2·7-3·0) in western Europe. After west and central Africa, eastern and southern Africa and south Asia had the second and third highest stillbirth rates in 2019. The global annual rate of reduction in stillbirth rate was estimated at 2·3% (90% UI 1·7-2·7) from 2000 to 2019, which was lower than the 2·9% (2·5-3·2) annual rate of reduction in neonatal mortality rate (for neonates aged <28 days) and the 4·3% (3·8-4·7) annual rate of reduction in mortality rate among children aged 1-59 months during the same period. Based on the lower bound of the 90% UIs, 114 countries had an estimated decrease in stillbirth rate since 2000, with four countries having a decrease of at least 50·0%, 28 having a decrease of 25·0-49·9%, 50 having a decrease of 10·0-24·9%, and 32 having a decrease of less than 10·0%. For the remaining 81 countries, we found no decrease in stillbirth rate since 2000. Of these countries, 34 were in sub-Saharan Africa, 16 were in east Asia and the Pacific, and 15 were in Latin America and the Caribbean. INTERPRETATION: Progress in reducing the rate of stillbirths has been slow compared with decreases in the mortality rate of children younger than 5 years. Accelerated improvements are most needed in the regions and countries with high stillbirth rates, particularly in sub-Saharan Africa. Future prevention of stillbirths needs increased efforts to raise public awareness, improve data collection, assess progress, and understand public health priorities locally, all of which require investment. FUNDING: Bill & Melinda Gates Foundation and the UK Foreign, Commonwealth and Development Office. |
| Safety and immunogenicity of two novel type 2 oral poliovirus vaccine candidates compared with a monovalent type 2 oral poliovirus vaccine in children and infants: two clinical trials.
Sáez-Llorens X , Bandyopadhyay AS , Gast C , Leon T , DeAntonio R , Jimeno J , Caballero MI , Aguirre G , Oberste MS , Weldon WC , Konopka-Anstadt JL , Modlin J , Bachtiar NS , Fix A , Konz J , Clemens R , Costa Clemens SA , Rüttimann R . Lancet 2020 397 (10268) 27-38
BACKGROUND: Continued emergence and spread of circulating vaccine-derived type 2 polioviruses and vaccine-associated paralytic poliomyelitis from Sabin oral poliovirus vaccines (OPVs) has stimulated development of two novel type 2 OPV candidates (OPV2-c1 and OPV2-c2) designed to have similar immunogenicity, improved genetic stability, and less potential to reacquire neurovirulence. We aimed to assess safety and immunogenicity of the two novel OPV candidates compared with a monovalent Sabin OPV in children and infants. METHODS: We did two single-centre, multi-site, partly-masked, randomised trials in healthy cohorts of children (aged 1-4 years) and infants (aged 18-22 weeks) in Panama: a control phase 4 study with monovalent Sabin OPV2 before global cessation of monovalent OPV2 use, and a phase 2 study with low and high doses of two novel OPV2 candidates. All participants received one OPV2 vaccination and subsets received two doses 28 days apart. Parents reported solicited and unsolicited adverse events. Type 2 poliovirus neutralising antibodies were measured at days 0, 7, 28, and 56, and stool viral shedding was assessed up to 28 days post-vaccination. Primary objectives were to assess safety in all participants and non-inferiority of novel OPV2 day 28 seroprotection versus monovalent OPV2 in infants (non-inferiority margin 10%). These studies were registered with ClinicalTrials.gov, NCT02521974 and NCT03554798. FINDINGS: The control study took place between Oct 23, 2015, and April 29, 2016, and the subsequent phase 2 study between Sept 19, 2018, and Sept 30, 2019. 150 children (50 in the control study and 100 of 129 assessed for eligibility in the novel OPV2 study) and 684 infants (110 of 114 assessed for eligibility in the control study and 574 of 684 assessed for eligibility in the novel OPV2 study) were enrolled and received at least one study vaccination. Vaccinations were safe and well tolerated with no causally associated serious adverse events or important medical events in any group. Solicited and unsolicited adverse events were overwhelmingly mild or moderate irrespective of vaccine or dose. Nearly all children were seroprotected at baseline, indicating high baseline immunity. In children, the seroprotection rate 28 days after one dose was 100% for monovalent OPV2 and both novel OPV2 candidates. In infants at day 28, 91 (94% [95% CI 87-98]) of 97 were seroprotected after receiving monovalent OPV2, 134 (94% [88-97]) of 143 after high-dose novel OPV2-c1, 122 (93% [87-97]) of 131 after low-dose novel OPV2-c1, 138 (95% [90-98]) of 146 after high-dose novel OPV2-c2, and 115 (91% [84-95]) of 127 after low-dose novel OPV2-c2. Non-inferiority was shown for low-dose and high-dose novel OPV2-c1 and high-dose novel OPV2-c2 despite monovalent OPV2 recipients having higher baseline immunity. INTERPRETATION: Both novel OPV2 candidates were safe, well tolerated, and immunogenic in children and infants. Novel OPV2 could be an important addition to our resources against poliovirus given the current epidemiological situation. FUNDING: Fighting Infectious Diseases in Emerging Countries and Bill & Melinda Gates Foundation. |
| Safety and immunogenicity of two novel type 2 oral poliovirus vaccine candidates compared with a monovalent type 2 oral poliovirus vaccine in healthy adults: two clinical trials.
De Coster I , Leroux-Roels I , Bandyopadhyay AS , Gast C , Withanage K , Steenackers K , De Smedt P , Aerssens A , Leroux-Roels G , Oberste MS , Konopka-Anstadt JL , Weldon WC , Fix A , Konz J , Wahid R , Modlin J , Clemens R , Costa Clemens SA , Bachtiar NS , Van Damme P . Lancet 2020 397 (10268) 39-50
BACKGROUND: Two novel type 2 oral poliovirus vaccine (OPV2) candidates, novel OPV2-c1 and novel OPV2-c2, designed to be more genetically stable than the licensed Sabin monovalent OPV2, have been developed to respond to ongoing polio outbreaks due to circulating vaccine-derived type 2 polioviruses. METHODS: We did two randomised studies at two centres in Belgium. The first was a phase 4 historical control study of monovalent OPV2 in Antwerp, done before global withdrawal of OPV2, and the second was a phase 2 study in Antwerp and Ghent with novel OPV2-c1 and novel OPV2-c2. Eligible participants were healthy adults aged 18-50 years with documented history of at least three polio vaccinations, including OPV in the phase 4 study and either OPV or inactivated poliovirus vaccine (IPV) in the novel OPV2 phase 2 study, with no dose within 12 months of study start. In the historical control trial, participants were randomly assigned to either one dose or two doses of monovalent OPV2. In the novel OPV2 trial, participants with previous OPV vaccinations were randomly assigned to either one or two doses of novel OPV2-c1 or to one or two doses of novel OPV2-c2. IPV-vaccinated participants were randomly assigned to receive two doses of either novel OPV2-c1, novel OPV2-c2, or placebo. Vaccine administrators were unmasked to treatment; medical staff performing safety and reactogenicity assessments or blood draws for immunogenicity assessments were masked. Participants received the first vaccine dose on day 0, and a second dose on day 28 if assigned to receive a second dose. Primary objectives were assessments and comparisons of safety up to 28 days after each dose, including solicited adverse events and serious adverse events, and immunogenicity (seroprotection rates on day 28 after the first vaccine dose) between monovalent OPV2 and the two novel OPV2 candidates. Primary immunogenicity analyses were done in the per-protocol population. Safety was assessed in the total vaccinated population-ie, all participants who received at least one dose of their assigned vaccine. The phase 4 control study is registered with EudraCT (2015-003325-33) and the phase 2 novel OPV2 study is registered with EudraCT (2018-001684-22) and ClinicalTrials.gov (NCT04544787). FINDINGS: In the historical control study, between Jan 25 and March 18, 2016, 100 volunteers were enrolled and randomly assigned to receive one or two doses of monovalent OPV2 (n=50 in each group). In the novel OPV2 study, between Oct 15, 2018, and Feb 27, 2019, 200 previously OPV-vaccinated volunteers were assigned to the four groups to receive one or two doses of novel OPV2-c1 or novel OPV2-c2 (n=50 per group); a further 50 participants, previously vaccinated with IPV, were assigned to novel OPV2-c1 (n=17), novel OPV2-c2 (n=16), or placebo (n=17). All participants received the first dose of assigned vaccine or placebo and were included in the total vaccinated population. All vaccines appeared safe; no definitely vaccine-related withdrawals or serious adverse events were reported. After first doses in previously OPV-vaccinated participants, 62 (62%) of 100 monovalent OPV2 recipients, 71 (71%) of 100 recipients of novel OPV2-c1, and 74 (74%) of 100 recipients of novel OPV2-c2 reported solicited systemic adverse events, four (monovalent OPV2), three (novel OPV2-c1), and two (novel OPV2-c2) of which were considered severe. In IPV-vaccinated participants, solicited adverse events occurred in 16 (94%) of 17 who received novel OPV2-c1 (including one severe) and 13 (81%) of 16 who received novel OPV2-c2 (including one severe), compared with 15 (88%) of 17 placebo recipients (including two severe). In previously OPV-vaccinated participants, 286 (97%) of 296 were seropositive at baseline; after one dose, 100% of novel OPV2 vaccinees and 97 (97%) of monovalent OPV2 vaccinees were seropositive. INTERPRETATION: Novel OPV2 candidates were as safe, well tolerated, and immunogenic as monovalent OPV2 in previously OPV-vaccinated and IPV-vaccinated adults. These data supported the further assessment of the vaccine candidates in children and infants. FUNDING: University of Antwerp and Bill & Melinda Gates Foundation. |
| Using real-time respirable dust monitors to address the silica health hazard in mining
Patts J . Rock Prod 2020 123 (7) 101-103 Mining operations, by their very nature, create a lot of dust, with varying percentages of silica content. Modern mining operators are well aware of the hazard created by respirable crystalline silica dust (RCS). Operators also need to recognize that silicosis is an irreversible occupational disease with terrible consequences including lung cancer, respiratory failure and tuberculosis. And there is no cure for silicosis - the only fix is to prevent the disease by limiting worker exposure. Based on the latest work-related lung disease surveillance report by the CDC, between 1990 and 1999, just over 20% of all total silica deaths occurred in the M/NM industry. And between 2000 and 2017, 12% of MSHA personal heath samples were greater than the MSHA PEL of 100 ug/m3 and 34% of those were greater than the OSHA PEL of 50 ug/m3. The benefit of real-time dust sensing lies in the ability to help the operator understand when certain exposures occurred. Pairing real-time sensing with Helmet-CAM technology, mine operators can also understand the specific tasks that led to those exposures. Further adding the use of an FTIR instrument and end-of-shift analysis can effectively yield silica estimation. All three of these approaches can be combined to estimate real-time silica concentrations. Importantly, to quantify worker exposure, there is no substitute for personal sampling. Complementary to personal sampling is area sampling, and when area sampling is conducted in real time then the dust levels present at mines in key areas can be quantified on a continuous, long-term basis. NIOSH has conducted many years of engineering control research and has published extensively on the topic. While the commonly used hierarchy of controls puts substitution as the best method for reducing worker exposures, often in mining the best controls are engineering-based, such as exhaust ventilation, dust capture systems, and total structure ventilation. Fueled by a growing global desire to understand indoor and outdoor air quality (most commonly combustion aerosols in the atmosphere), numerous "low-cost" particulate sensors have been developed and marketed to those interested in quantifying their local air quality. Further, studies have compared these sensors to research-grade federal environmental monitoring devices and, after some appropriate scaling factor is applied, the agreement can be quite good. NIOSH recently began a new research effort in the fall of 2019 which aims to evaluate the applicability of these sensors not to ambient aerosols, but to the perhaps more challenging role of measuring real-time mining dust levels. This work poses many challenges - larger and more varied dusts, higher dust concentrations, and harsh environments - but the potential to inexpensively quantify mining dust levels in real time is intriguing. If low-cost area dust sensing for mining becomes a reality, it's possible that plant operators could apply engineering controls more widely by justifying installations that would most efficiently reduce both area exposures and individual worker exposures, providing a significant health benefit. |
| An Isothermal, Multiplex Amplification Assay for Detection and Genotyping of Human Papillomaviruses in Formalin-Fixed, Paraffin-Embedded Tissues.
Tang YW , Lozano L , Chen X , Querec TD , Katabi N , Moreno-Docon A , Wang H , Fix D , De Brot L , McMillen TA , Yoon JY , Torroba A , Wang Y , Unger ER , Park KJ . J Mol Diagn 2020 22 (3) 419-428
Rapid and accurate identification of human papillomavirus (HPV) is important for both clinical management and population screening. We performed analytic validation of Atila AmpFire Multiplex HPV assays on formalin-fixed, paraffin-embedded (FFPE) cervix/vulva and oropharynx diagnostic tissue samples. The AmpFire assay incorporates a novel isothermal multiplex amplification coupled with real-time fluorescent detection to detect and genotype 15 high-risk (HR) HPV genotypes. Limits of detection determined by plasmids cloned with HPV genotype-specific sequences were 2 copies/reaction for HPV16, HPV18, and some HR HPV genotypes, and 20 copies/reaction for the remaining HR HPV genotypes. The performance of the AmpFire assays in clinical samples was evaluated using 214 FFPE specimens. The AmpFire assay failed in one clinical specimen for an invalid rate of 0.5%. The AmpFire assay detected HPV in clinical samples with positive percent agreements of 100.0% for HPV16, 100.0% for HPV18, and 94.7% for non-16/18 HR-HPV, and 100% negative percent agreements for HPV16, HPV18, and non-16/18 HR-HPV. Qualitative detection agreement was obtained in the reproducibility study. In summary, the Atila AmpFire HPV assay demonstrated excellent analytic sensitivity and specificity for detection and genotyping of 15 HR HPV genotypes. Assay parameters of simple specimen processing, small sample size requirement, rapid turnaround time, and being near instrument-free render it well suited for HPV detection and genotyping in FFPE specimens. |
| Evaluation of pre-analytic heat treatment protocol used in the CDC Nijmegen-Bethesda assay for heat inactivation of extended half-life haemophilia treatment products
Payne AB , Ellingsen D , Driggers J , Bean CJ , Miller CH . Haemophilia 2019 26 (1) e28-e30 Detection of low-titer factor VIII (FVIII) or factor IX (FIX) inhibitors can be difficult in the presence of endogenous or therapeutic factor.1 Pre-analytic heat treatment (PHT) of patient plasma specimens at 56⁰C for 30 minutes followed by centrifugation prior to measurement of the inhibitor titer is important to eliminate interference caused by endogenous or therapeutic factor in the specimen and to avoid the need for a washout period.1 PHT has been previously shown to enable more accurate determination of the inhibitor titer without removing antibodies in the context of traditional factor replacement products.2 |
| Mathematical model of thrombin generation and bleeding phenotype in Amish carriers of Factor IX:C deficiency vs. controls
Gupta S , Bravo MC , Heiman M , Nakar C , Brummel-Ziedins K , Miller CH , Shapiro A . Thromb Res 2019 182 43-50 INTRODUCTION: Factor IX:C (FIX:C) levels vary in hemophilia B carriers even in pedigrees with a unifying genetic defect. Analyzing the balance between pro-and anticoagulants might increase our understanding of carriers' bleeding potential. AIM: In this research study, we evaluated bleeding scores (BS) and a novel mathematical model of thrombin generation (TG) in Amish FIX:C deficient carriers and controls. METHODS: Blood samples and BS were obtained from post-menarchal females, including 59 carriers and 57 controls from the same extended pedigree. Factors II, V, VII, VIII, IX, X, antithrombin, tissue factor pathway inhibitor and protein C were assayed to generate mathematical models of TG in response to 5pM tissue factor (TF) and for TF+thrombomodulin. BS was based on a modification of the MCMDM-1VWD scoring system. RESULTS: Carriers had a lower mean FIX:C (68% vs. 119%), von Willebrand factor antigen (108 vs.133) and Tissue activatable fibrinolysis inhibitor (103 vs. 111) compared to controls; both groups had a similar mean BS. Carriers demonstrated significantly lower TG parameters on both mathematical models compared to controls. Carriers with FIX:C</=50% had lower TG curves than those >50% but similar BS. CONCLUSION: Thrombin generation showed significant differences between carriers and controls, between low (</=50%) and high (>50%) FIX:C carriers, and specifically in the TF+thrombomodulin model, between high FIX:C carriers and controls, although the BS were not different. |
| Laboratory testing for factor VIII and IX inhibitors in haemophilia: A review
Miller CH . Haemophilia 2018 24 (2) 186-197 Inhibitors are antibodies directed against haemophilia treatment products which interfere with their function. Factor VIII (FVIII) inhibitors in haemophilia A and factor IX (FIX) inhibitors in haemophilia B are significant clinically when they require a change in a patient's treatment regimen. Their persistence may increase morbidity and mortality. Multiple laboratory tests are now available for detecting and understanding inhibitors in haemophilia. Inhibitors are traditionally measured by their interference in clotting or chromogenic factor assays. They may also be detected using immunologic assays, such as enzyme-linked immunosorbent assay or fluorescence immunoassay. Anti-FVIII or anti-FIX antibodies of IgG4 subclass best correlate with the presence of functional inhibitors. Improvements in inhibitor measurement have been recently introduced. Preanalytical heat treatment of patient specimens allows testing of patients without delaying treatment. Use of chromogenic and immunologic assays may aid in identification of false-positive results, which are frequent among low-titre inhibitors. Validated reagent substitutions can be used to reduce assay cost. New methods for defining assay positivity and reporting low-titre inhibitors have been suggested. Challenges remain in the areas of quality control, assay standardization, monitoring of patients undergoing immune tolerance induction therapy and testing in the presence of modified and novel treatment products. |
| Quick fixes to improve workers' health: Results using engineering assessment technology
Haas EJ , Cecala AB . Min Eng 2017 69 (7) 105-109 Personal respirable dust sampling and the evaluation of control technologies have been providing exposure information to the mining industry but not necessarily in a way that shows how technology can be integrated to provide organizational support and resources for workers to mitigate dust sources on site. In response, the U.S. National Institute for Occupational Safety and Health (NIOSH) used previously developed Helmet-CAM technology to design and engage in a behavioral/engineering cooperative intervention to initiate and enhance mine site conversations about the risks and potential occurrences of respirable silica dust exposures on the job as well as provide impetus and solutions for mitigating higher sources of dust. The study involved 48 workers from five mine sites, who agreed to participate between April 2015 and September 2016. Using the Helmet-CAM in this series of longitudinal interventions revealed several exposure trends in respirable silica dust sources and, in many cases, simple quick-fix strategies to reduce their sources. This paper focuses on several specific identified sources of dust that were elevated but could be reduced through basic engineering fixes, low-cost resources, and supportive communication from management to remind and engage workers in protective work practices. |
| Survey of the anti-factor IX immunoglobulin profiles in patients with hemophilia B using a fluorescence-based immunoassay
Boylan B , Rice AS , Neff AT , Manco-Johnson MJ , Kempton CL , Miller CH . J Thromb Haemost 2016 14 (10) 1931-1940 BACKGROUND: Hemophilia B (HB) is an inherited bleeding disorder caused by the absence or dysfunction of coagulation factor IX (FIX). A subset of patients who have HB develop neutralizing alloantibodies (inhibitors) against FIX following infusion therapy. HB prevalence and the proportion of patients who develop inhibitors are much lower than that of hemophilia A (HA), which makes studies of inhibitors in patients with HB challenging due to the limited availability of samples. As a result, there is a knowledge gap regarding HB inhibitors. OBJECTIVE: Evaluate the largest group of inhibitor positive HB patients studied to date to assess the relationship between anti-FIX antibody profiles and inhibitor formation METHODS: A fluorescence immunoassay (FLI) was used to detect anti-FIX antibodies in plasma samples from 37 patients with HB RESULTS: Assessments of antibody profiles showed that anti-FIX IgG1-4 , IgA, and IgE were detected significantly more often in patients with a positive Nijmegen-Bethesda Assay (NBA). All NBA-positive samples were positive for IgG4 . Anti-FIX IgG4 demonstrated a strong correlation with the NBA, while correlations were significant, yet more moderate, for anti-FIX IgG1-2 and IgA CONCLUSIONS: The anti-FIX antibody profile in HB patients who develop inhibitors is diverse and correlates well with the NBA across immunoglobulin (sub)class, and anti-FIX IgG4 is particularly relevant to functional inhibition. The anti-FIX FLI may serve as a useful tool to confirm the presence of antibodies in patients who have low positive NBA results and to more clearly define, predict, and treat alloantibody formation against FIX. |
| Evaluation of pulmonary and systemic toxicity following lung exposure to graphite nanoplates: A member of the graphene-based nanomaterial family
Roberts JR , Mercer RR , Stefaniak AB , Seehra MS , Geddam UK , Chaudhuri IS , Kyrlidis A , Kodali VK , Sager T , Kenyon A , Bilgesu SA , Eye T , Scabilloni JF , Leonard SS , Fix NR , Schwegler-Berry D , Farris BY , Wolfarth MG , Porter DW , Castranova V , Erdely A . Part Fibre Toxicol 2016 13 (1) 34 BACKGROUND: Graphene, a monolayer of carbon, is an engineered nanomaterial (ENM) with physical and chemical properties that may offer application advantages over other carbonaceous ENMs, such as carbon nanotubes (CNT). The goal of this study was to comparatively assess pulmonary and systemic toxicity of graphite nanoplates, a member of the graphene-based nanomaterial family, with respect to nanoplate size. METHODS: Three sizes of graphite nanoplates [20 mum lateral (Gr20), 5 mum lateral (Gr5), and <2 mum lateral (Gr1)] ranging from 8-25 nm in thickness were characterized for difference in surface area, structure,, zeta potential, and agglomeration in dispersion medium, the vehicle for in vivo studies. Mice were exposed by pharyngeal aspiration to these 3 sizes of graphite nanoplates at doses of 4 or 40 mug/mouse, or to carbon black (CB) as a carbonaceous control material. At 4 h, 1 day, 7 days, 1 month, and 2 months post-exposure, bronchoalveolar lavage was performed to collect fluid and cells for analysis of lung injury and inflammation. Particle clearance, histopathology and gene expression in lung tissue were evaluated. In addition, protein levels and gene expression were measured in blood, heart, aorta and liver to assess systemic responses. RESULTS: All Gr samples were found to be similarly composed of two graphite structures and agglomerated to varying degrees in DM in proportion to the lateral dimension. Surface area for Gr1 was approximately 7-fold greater than Gr5 and Gr20, but was less reactive reactive per m(2). At the low dose, none of the Gr materials induced toxicity. At the high dose, Gr20 and Gr5 exposure increased indices of lung inflammation and injury in lavage fluid and tissue gene expression to a greater degree and duration than Gr1 and CB. Gr5 and Gr20 showed no or minimal lung epithelial hypertrophy and hyperplasia, and no development of fibrosis by 2 months post-exposure. In addition, the aorta and liver inflammatory and acute phase genes were transiently elevated in Gr5 and Gr20, relative to Gr1. CONCLUSIONS: Pulmonary and systemic toxicity of graphite nanoplates may be dependent on lateral size and/or surface reactivity, with the graphite nanoplates > 5 mum laterally inducing greater toxicity which peaked at the early time points post-exposure relative to the 1-2 mum graphite nanoplate. |
| Pulmonary toxicity of indium-tin oxide production facility particles in rats
Badding MA , Fix NR , Orandle MS , Barger MW , Dunnick KM , Cummings KJ , Leonard SS . J Appl Toxicol 2015 36 (4) 618-26 Indium-tin oxide (ITO) is used to make transparent conductive coatings for touch-screen and liquid crystal display electronics. Occupational exposures to potentially toxic particles generated during ITO production have increased in recent years as the demand for consumer electronics continues to rise. Previous studies have demonstrated cytotoxicity in vitro and animal models have shown pulmonary inflammation and injury in response to various indium-containing particles. In humans, pulmonary alveolar proteinosis (PAP) and fibrotic interstitial lung disease have been observed in ITO facility workers. However, which indium materials or specific processes in the workplace may be the most toxic to workers is unknown. Here we examined the pulmonary toxicity of three different particle samples that represent real-life worker exposures, as they were collected at various production stages throughout an ITO facility. Indium oxide (In2 O3 ), sintered ITO (SITO) and ventilation dust (VD) particles each caused pulmonary inflammation and damage in rats over a time course (1, 7 and 90 days post-intratracheal instillation), but SITO and VD appeared to induce greater toxicity in rat lungs than In2 O3 at a dose of 1 mg per rat. Downstream pathological changes such as PAP and fibrosis were observed in response to all three particles 90 days after treatment, with a trend towards greatest severity in animals exposed to VD when comparing animals that received the same dose. These findings may inform workplace exposure reduction efforts and provide a better understanding of the pathogenesis of an emerging occupational health issue. |
| Sintered indium-tin oxide particles induce pro-inflammatory responses in vitro, in part through inflammasome activation
Badding MA , Schwegler-Berry D , Park JH , Fix NR , Cummings KJ , Leonard SS . PLoS One 2015 10 (4) e0124368 Indium-tin oxide (ITO) is used to make transparent conductive coatings for touch-screen and liquid crystal display electronics. As the demand for consumer electronics continues to increase, so does the concern for occupational exposures to particles containing these potentially toxic metal oxides. Indium-containing particles have been shown to be cytotoxic in cultured cells and pro-inflammatory in pulmonary animal models. In humans, pulmonary alveolar proteinosis and fibrotic interstitial lung disease have been observed in ITO facility workers. However, which ITO production materials may be the most toxic to workers and how they initiate pulmonary inflammation remain poorly understood. Here we examined four different particle samples collected from an ITO production facility for their ability to induce pro-inflammatory responses in vitro. Tin oxide, sintered ITO (SITO), and ventilation dust particles activated nuclear factor kappa B (NFkappaB) within 3 h of treatment. However, only SITO induced robust cytokine production (IL-1beta, IL-6, TNFalpha, and IL-8) within 24 h in both RAW 264.7 mouse macrophages and BEAS-2B human bronchial epithelial cells. Our lab and others have previously demonstrated SITO-induced cytotoxicity as well. These findings suggest that SITO particles activate the NLRP3 inflammasome, which has been implicated in several immune-mediated diseases via its ability to induce IL-1beta release and cause subsequent cell death. Inflammasome activation by SITO was confirmed, but it required the presence of endotoxin. Further, a phagocytosis assay revealed that pre-uptake of SITO or ventilation dust impaired proper macrophage phagocytosis of E. coli. Our results suggest that adverse inflammatory responses to SITO particles by both macrophage and epithelial cells may initiate and propagate indium lung disease. These findings will provide a better understanding of the molecular mechanisms behind an emerging occupational health issue. |
| Intravenous and gastric cerium dioxide nanoparticle exposure disrupts microvascular smooth muscle signaling
Minarchick VC , Stapleton PA , Fix NR , Leonard SS , Sabolsky EM , Nurkiewicz TR . Toxicol Sci 2014 144 (1) 77-89 Cerium dioxide nanoparticles (CeO2 NP) hold great therapeutic potential, but the in vivo effects of non-pulmonary exposure routes are unclear. The first aim was to determine whether microvascular function is impaired after intravenous and gastric CeO2 NP exposure. The second aim was to investigate the mechanism(s) of action underlying microvascular dysfunction following CeO2 NP exposure. Rats were exposed to CeO2 NP (primary diameter: 4 +/- 1 nm, surface area: 81.36 m2/g) by intratracheal instillation, intravenous injection, or gastric gavage. Mesenteric arterioles were harvested 24 h post-exposure and vascular function was assessed using an isolated arteriole preparation. Endothelium-dependent and -independent function and vascular smooth muscle (VSM) signaling [soluble guanylyl cyclase (sGC), and cyclic guanosine monophosphate (cGMP)] were assessed. Reactive oxygen species (ROS) generation and nitric oxide (NO) production were analyzed. Compared to controls, endothelium-dependent and -independent dilation were impaired following intravenous injection (by 61% and 45%) and gastric gavage (by 63% and 49%). However, intravenous injection resulted in greater microvascular impairment (16% and 35%) compared to gastric gavage at an identical dose (100 mug). Furthermore, sGC activation and cGMP responsiveness were impaired following pulmonary, intravenous, and gastric CeO2 NP treatment. Finally, nanoparticle exposure resulted in route-dependent, increased ROS generation and decreased NO production. These results indicate that CeO2 NP exposure route differentially impairs microvascular function, which may be mechanistically linked to decreased NO production and subsequent VSM signaling. Fully understanding the mechanisms behind CeO2 NP in vivo effects is a critical step in the continued therapeutic development of this nanoparticle. |
| Generation of reactive oxygen species from silicon nanowires
Leonard SS , Cohen GM , Kenyon AJ , Schwegler-Berry D , Fix NR , Bangsaruntip S , Roberts JR . Environ Health Insights 2014 8 21-29 Processing and synthesis of purified nanomaterials of diverse composition, size, and properties is an evolving process. Studies have demonstrated that some nanomaterials have potential toxic effects and have led to toxicity research focusing on nanotoxicology. About two million workers will be employed in the field of nanotechnology over the next 10 years. The unknown effects of nanomaterials create a need for research and development of techniques to identify possible toxicity. Through a cooperative effort between National Institute for Occupational Safety and Health and IBM to address possible occupational exposures, silicon-based nanowires (SiNWs) were obtained for our study. These SiNWs are anisotropic filamentary crystals of silicon, synthesized by the vapor–liquid–solid method and used in bio-sensors, gas sensors, and field effect transistors. Reactive oxygen species (ROS) can be generated when organisms are exposed to a material causing cellular responses, such as lipid peroxidation, H2O2 production, and DNA damage. SiNWs were assessed using three different in vitro environments (H2O2, RAW 264.7 cells, and rat alveolar macrophages) for ROS generation and possible toxicity identification. We used electron spin resonance, analysis of lipid peroxidation, measurement of H2O2 production, and the comet assay to assess generation of ROS from SiNW and define possible mechanisms. Our results demonstrate that SiNWs do not appear to be significant generators of free radicals. |
| Lung biodurability and free radical production of cellulose nanomaterials
Stefaniak AB , Seehra MS , Fix NR , Leonard SS . Inhal Toxicol 2014 26 (12) 733-49 The potential applications of cellulose nanomaterials in advanced composites and biomedicine makes it imperative to understand their pulmonary exposure to human health. Here, we report the results on the biodurability of three cellulose nanocrystal (CNC), two cellulose nanofibril (CNF) and a benchmark cellulose microcrystal (CMC) when exposed to artificial lung airway lining fluid (SUF, pH 7.3) for up to 7 days and alveolar macrophage phagolysosomal fluid (PSF, pH 4.5) for up to 9 months. X-ray diffraction analysis was used to monitor biodurability and thermogravimetry, surface area, hydrodynamic diameter, zeta potential and free radical generation capacity of the samples were determined (in vitro cell-free and RAW 264.7 cell line models). The CMC showed no measurable changes in crystallinity (xCR) or crystallite size D in either SUF or PSF. For one CNC, a slight decrease in xCR and D in SUF was observed. In acidic PSF, a slight increase in xCR with exposure time was observed, possibly due to dissolution of the amorphous component. In a cell-free reaction with H2O2, radicals were observed; the CNCs and a CNF generated significantly more [Formula: see text] radicals than the CMC (p < 0.05). The [Formula: see text] radical production correlates with particle decomposition temperature and is explained by the higher surface area to volume ratio of the CNCs. Based on their biodurability, mechanical clearance would be the primary mechanism for lung clearance of cellulose materials. The production of [Formula: see text] radicals indicates the need for additional studies to characterize the potential inhalation hazards of cellulose. |
| Cytotoxicity and characterization of particles collected from an indium-tin oxide production facility
Badding MA , Stefaniak AB , Fix NR , Cummings KJ , Leonard SS . J Toxicol Environ Health A 2014 77 (20) 1193-209 Occupational exposure to indium compound particles has recently been associated with lung disease among workers in the indium-tin oxide (ITO) industry. Previous studies suggested that excessive alveolar surfactant and reactive oxygen species (ROS) may play a role in the development of pulmonary lesions following exposure to indium compounds. However, toxicity at the cellular level has not been comprehensively evaluated. Thus, the aim of this study was to assess which, if any, compounds encountered during ITO production are toxic to cultured cells and ultimately contribute to the pathogenesis of indium lung disease. The compounds used in this study were collected from eight different processing stages at an ITO production facility. Enhanced dark field imaging showed 5 of the compounds significantly associated with cells within 1 h, suggesting that cellular reactions to the compound particles may be occurring rapidly. To examine the potential cytotoxic effects of these associations, ROS generation, cell viability, and apoptosis were evaluated following exposures in RAW 264.7 mouse monocyte macrophage and BEAS-2B human bronchial epithelial cell lines. Both exhibited reduced viability with exposures, while apoptosis only occurred in RAW 264.7 cells. Our results suggested that excessive ROS production is likely not the predominant mechanism underlying indium-induced lung disease. However, the effects on cell viability reveal that several of the compounds are cytotoxic, and therefore, exposures need to be carefully monitored in the industrial setting. |
| Females with FVIII and FIX deficiency have reduced joint range of motion
Sidonio RF , Mili FD , Li T , Miller CH , Hooper WC , DeBaun MR , Soucie M . Am J Hematol 2014 89 (8) 831-6 Little is known about rates of joint bleeding among females with FVIII/FIX deficiency or hemophilia carriers. In a cross-sectional study, we tested the hypothesis that females with FVIII or FIX deficiency enrolled in the Universal Data Collection (UDC) project had a reduced mean overall joint range of motion (ROM) compared with historic controls from the Normal Joint Study. Demographics, clinical characteristics, and joint ROM measurements on 303 females without a bleeding disorder and 148 females with FVIII and FIX deficiency, respectively, between the ages of 2-69 years and a body mass index (BMI) ≤ 35 were compared. Multivariate linear regression was performed with the overall joint ROM (sum of the right and left ROM measurements of five joints) as the dependent variable and FVIII or FIX activity as the independent variable adjusting for age, race, BMI, and number of joint bleeds reported over the last 6 months. As FVIII and FIX activity decreased, the mean overall joint ROM became reduced and in most cases was significantly lower than that of the controls regardless of age and clinical hemophilia severity. Further investigation of reduced joint ROM as evidence of subclinical joint bleeding in females with FVIII and FIX deficiency is warranted. |
| A comparison of cytotoxicity and oxidative stress from welding fumes generated with a new nickel-, copper-based consumable versus mild and stainless steel-based welding in RAW 264.7 mouse macrophages
Badding MA , Fix NR , Antonini JM , Leonard SS . PLoS One 2014 9 (6) e101310 Welding processes that generate fumes containing toxic metals, such as hexavalent chromium (Cr(VI)), manganese (Mn), and nickel (Ni), have been implicated in lung injury, inflammation, and lung tumor promotion in animal models. While federal regulations have reduced permissible worker exposure limits to Cr(VI), this is not always practical considering that welders may work in confined spaces and exhaust ventilation may be ineffective. Thus, there has been a recent initiative to minimize the potentially hazardous components in welding materials by developing new consumables containing much less Cr(VI) and Mn. A new nickel (Ni) and copper (Cu)-based material (Ni-Cu WF) is being suggested as a safer alternative to stainless steel consumables; however, its adverse cellular effects have not been studied. This study compared the cytotoxic effects of the newly developed Ni-Cu WF with two well-characterized welding fumes, collected from gas metal arc welding using mild steel (GMA-MS) or stainless steel (GMA-SS) electrodes. RAW 264.7 mouse macrophages were exposed to the three welding fumes at two doses (50 microg/ml and 250 microg/ml) for up to 24 hours. Cell viability, reactive oxygen species (ROS) production, phagocytic function, and cytokine production were examined. The GMA-MS and GMA-SS samples were found to be more reactive in terms of ROS production compared to the Ni-Cu WF. However, the fumes from this new material were more cytotoxic, inducing cell death and mitochondrial dysfunction at a lower dose. Additionally, pre-treatment with Ni-Cu WF particles impaired the ability of cells to phagocytize E. coli, suggesting macrophage dysfunction. Thus, the toxic cellular responses to welding fumes are largely due to the metal composition. The results also suggest that reducing Cr(VI) and Mn in the generated fume by increasing the concentration of other metals (e.g., Ni, Cu) may not necessarily improve welder safety. |
| A chemical free, nanotechnology-based method for airborne bacterial inactivation using engineered water nanostructures
Pyrgiotakis G , McDevitt J , Bordini A , Diaz E , Molina R , Watson C , Deloid G , Lenard S , Fix N , Mizuyama Y , Yamauchi T , Brain J , Demokritou P . Environ Sci Nano 2014 1 (1) 15-26 Airborne pathogens are associated with the spread of infectious diseases and increased morbidity and mortality. Herein we present an emerging chemical free, nanotechnology-based method for airborne pathogen inactivation. This technique is based on transforming atmospheric water vapor into Engineered Water Nano-Structures (EWNS) via electrospray. The generated EWNS possess a unique set of physical, chemical, morphological and biological properties. Their average size is 25 nm and they contain reactive oxygen species (ROS) such as hydroxyl and superoxide radicals. In addition, EWNS are highly electrically charged (10 electrons per particle on average). A link between their electric charge and the reduction of their evaporation rate was illustrated resulting in an extended lifetime (over an hour) at room conditions. Furthermore, it was clearly demonstrated that the EWNS have the ability to interact with and inactivate airborne bacteria. Finally, inhaled EWNS were found to have minimal toxicological effects, as illustrated in an acute in-vivo inhalation study using a mouse model. In conclusion, this novel, chemical free, nanotechnology-based method has the potential to be used in the battle against airborne infectious diseases. |
| An analysis of root cause identification and continuous quality improvement in public health H1N1 after-action reports
Singleton CM , Debastiani S , Rose D , Kahn EB . J Public Health Manag Pract 2013 20 (2) 197-204 OBJECTIVE: To identify the extent to which the Homeland Security Exercise and Evaluation Program's (HSEEP) After Action Report/Improvement Plan (AAR/IP) template was followed by public health entities and facilitated the identification of detailed corrective actions and continuous improvement. DESIGN: Data were drawn from the US H1N1 Public Health Emergency Response (PHER) federal grant awardees (n = 62). After action report/improvement plan text was examined to identify the presence of AAR/IP HSEEP elements and characterized as "minimally complete," "partially complete," or "complete." Corrective actions (CA) and recommendations within the IP focusing on performance deficits were coded as specific, measurable, and time-bound, and whether they were associated with a problem that met root cause criteria and whether the CA/recommendation was intended to address or fix the root cause. MAIN OUTCOME MEASURES: A total of 2619 CA/recommendations were identified. More than half (n = 1480, 57%) addressed root causes. Corrective actions/recommendations associated with complete AARs more frequently addressed root cause (58% vs 51%, chi = 9.1, P < 0.003) and were more specific (34% vs 23%, chi = 32.3, P < 0.0001), measurable (30% vs 18%, chi = 37.9, P < 0.0001), and time-bound (38% vs 15%, chi = 115.5, P < 0.0001) than partially complete AARs. The same pattern was not observed with completeness of IPs. Corrective actions and recommendations were similarly specific and measurable. Recommendations significantly addressed root cause more than CAs. CONCLUSIONS: Our analysis indicates a possible lack of awardee distinction between CA and recommendations in AARs. As HSEEP adapts to align with the 2011 National Preparedness Goal and National Preparedness System, future HSEEP documents should emphasize the importance of root cause analysis as a required element within AAR documents and templates in the exercise and real incident environment, as well as the need for specific and measurable CAs. |
| Inactivation of infectious virus and serological detection of virus antigen in Rift Valley fever virus-exposed mosquitoes fixed with paraformaldehyde
Kading R , Crabtree M , Miller B . J Virol Methods 2013 189 (1) 184-8 Formaldehyde is routinely used to fix tissues in preparation for pathology studies, however concerns remain that treatment of tissues with cellular fixatives may not entirely inactivate infectious virus particles. This concern is of particular regulatory importance for research involving viruses that are classified as select agents such as Rift Valley fever virus (RVFV). Therefore, the specific aims of this study were to 1) assay RVFV-exposed Aedes aegypti mosquitoes fixed in 4% paraformaldehyde for the presence of infectious RVFV particles at various time points following infection and 2) demonstrate the utility of immunofluorescence assay (IFA) for the detection of RVFV antigen in various tissues of paraformaldehyde-fixed mosquitoes. Mosquitoes were administered an infectious blood meal containing one of two strains of RVFV, harvested at various time points following infection, intrathoracically-inoculated with 4% paraformaldehyde, and fixed overnight at 4 degrees C. The infection status of a subset of mosquitoes was verified by IFA on leg tissues prior to fixation, and infectivity of RVFV in fixed mosquito carcasses was determined by Vero cell plaque assay. Paraformaldehyde-fixed mosquitoes harvested 14 days post infection were also paraffin-embedded and sectioned for detection of RVFV antigen to particular tissues by IFA. None of the RVFV-exposed mosquitoes tested by Vero cell plaque assay contained infectious RVFV after fixation. Furthermore, incubation of mosquito sections with trypsin prior to antibody staining is recommended for optimal visualization of RVFV antigen in infected mosquito tissues by IFA. |
| A bounding estimate of neutron dose based on measured photon dose around single pass reactors at the Hanford site
Taulbee TD , Glover SE , Macievic GV , Hunacek M , Smith C , DeBord GW , Morris D , Fix J . Health Phys 2010 99 (1) 26-38 Neutron and photon radiation survey records have been used to evaluate and develop a neutron to photon (NP) ratio to reconstruct neutron doses to workers around Hanford's single pass reactors that operated from 1945 to 1972. A total of 5,773 paired neutron and photon measurements extracted from 57 boxes of survey records were used in the development of the NP ratio. The development of the NP ratio enables the use of the recorded dose from an individual's photon dosimeter badge to be used to estimate the unmonitored neutron dose. The Pearson rank correlation between the neutron and photon measurements was 0.71. The NP ratio best fit a lognormal distribution with a geometric mean (GM) of 0.8, a geometric standard deviation (GSD) of 2.95, and the upper 95 th % of this distribution was 4.75. An estimate of the neutron dose based on this NP ratio is considered bounding due to evidence that up to 70% of the total photon exposure received by workers around the single pass reactors occurs during shutdown maintenance and refueling activities when there is no significant neutron exposure. Thus when this NP ratio is applied to the total measured photon dose from an individual film badge dosimeter, the resulting neutron dose is considered bounded. |
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