333 research outputs found

    Whole genome sequencing-based mapping and candidate identification of mutations from fixed zebrafish tissue

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    As forward genetic screens in zebrafish become more common, the number of mutants that cannot be identified by gross morphology or through transgenic approaches, such as many nervous system defects, has also increased. Screening for these difficult-to-visualize phenotypes demands techniques such as whole-mount in situ hybridization (WISH) or antibody staining, which require tissue fixation. To date, fixed tissue has not been amenable for generating libraries for whole genome sequencing (WGS). Here, we describe a method for using genomic DNA from fixed tissue and a bioinformatics suite for WGS-based mapping of zebrafish mutants. We tested our protocol using two known zebrafish mutant alleles, gpr126st49 and egr2bfh227, both of which cause myelin defects. As further proof of concept we mapped a novel mutation, stl64, identified in a zebrafish WISH screen for myelination defects. We linked stl64 to chromosome 1 and identified a candidate nonsense mutation in the F-box and WD repeat domain containing 7 (fbxw7) gene. Importantly, stl64 mutants phenocopy previously described fbxw7vu56 mutants, and knockdown of fbxw7 in wild-type animals produced similar defects, demonstrating that stl64 disrupts fbxw7. Together, these data show that our mapping protocol can map and identify causative lesions in mutant screens that require tissue fixation for phenotypic analysis

    No Evidence of HIV and SIV Sequences in Two Separate Lots of Polio Vaccines Used in the First U.S. Polio Vaccine Campaign

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    AbstractWe obtained sealed vials of two different polio vaccine lots, expiration date 1955, which were used in the first U.S. polio vaccine campaign. These early lots were pulled from the market because they contained live infectious poliovirus which caused polio in some of the vaccines. Theoretically, these vaccines could have contained other infectious retroviruses, including HIV. No viral sequences were detected using RT-PCR analyses with primers capable of amplifying chimpanzee SIV and HIV-1-related viruses nor with primers for macaque SIV, sooty mangabey SIV, and HIV-2-related viruses. Poliovirus sequences were readily amplified by RT-PCR, suggesting that the technique used would have detected SIV or HIV sequences, if present

    8-Bromo­naphthalen-1-amine

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    The title compound, C10H8BrN, was obtained by slow addition of sodium azide to 8-bromo-1-naphthoic acid, followed by addition of aqueous ammonia. The crude product was crystallized from petroleum ether to give pink crystals. Compared to other 1,8-disubstituted naphthalene compounds, this compound exhibits less strain between the 1 and 8 substituents. Additionally, the NH protons form both intra- and inter­molecular hydrogen bonds. The naphthalene units are arranged in a herring-bone stacking motif

    Atypical propylthiouracil-induced ANCA-positive vasculitis: report of a case with unusual clinical and histopathologic findings

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    The side effects of propylthiouracil, including cytopenia and vasculitis, are well established.  We present an interesting case in which cytopenia and cutaneous vasculopathy occurred concomitantly in a critically ill patient.  The patient was initially treated for suspected infection until dermatologic and rheumatologic workup revealed ANCA-positivity and vasculopathy on histopathology, most consistent with an atypical presentation of ANCA-positive vasculitis.  Upon initiation of immunosuppressive therapy, the patient’s condition rapidly improved emphasizing the importance of early recognition of this condition

    Myelinating Schwann cells ensheath multiple axons in the absence of E3 ligase component Fbxw7

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    In the central nervous system (CNS), oligodendrocytes myelinate multiple axons; in the peripheral nervous system (PNS), Schwann cells (SCs) myelinate a single axon. Why are the myelinating potentials of these glia so fundamentally different? Here, we find that loss of Fbxw7, an E3 ubiquitin ligase component, enhances the myelinating potential of SCs. Fbxw7 mutant SCs make thicker myelin sheaths and sometimes appear to myelinate multiple axons in a fashion reminiscent of oligodendrocytes. Several Fbxw7 mutant phenotypes are due to dysregulation of mTOR; however, the remarkable ability of mutant SCs to ensheathe multiple axons is independent of mTOR signaling. This indicates distinct roles for Fbxw7 in SC biology including modes of axon interactions previously thought to fundamentally distinguish myelinating SCs from oligodendrocytes. Our data reveal unexpected plasticity in the myelinating potential of SCs, which may have important implications for our understanding of both PNS and CNS myelination and myelin repair

    Maternal Influences on Nausea and Vomiting in Early Pregnancy

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    Symptoms of nausea and vomiting in early pregnancy (NVP) are common among pregnant women, but whether some women are more likely than others to experience these symptoms has not been well established. We examined potential risk factors for NVP symptom severity, timing of onset, and duration. We included 2,407 newly pregnant women who participated in a prospective cohort study on early pregnancy health between 2000 and 2004 in three U.S. cities. Data on NVP and other health information were collected through telephone interviews, early gestation ultrasound, and medical record abstractions. Generalized linear models were used to model possible risk factors for each NVP characteristic. Eighty-nine percent of women had NVP; for 99% of these, symptoms started in the first trimester. None of the characteristics examined were associated with having NVP. Among those with NVP, increasing risk of delayed symptoms onset was associated with advancing maternal age; increased risks were also seen among non-Hispanic Black [Risk ratio (RR) = 4.3, 95% confidence interval (CI): 1.6,11.6] and Hispanic women (RR = 2.3, 95% CI:0.4,11.5). NVP symptoms for multigravidae were more likely to last beyond the first trimester with each additional pregnancy. Most pregnant women experienced NVP. Nearly all of them, regardless of characteristics examined, had symptoms beginning in the first trimester. Maternal age, race/ethnicity, and gravidity were associated with delayed onset and symptoms that persisted into the second trimester

    Cancer Incidence in World Trade Center Rescue and Recovery Workers, 2001–2008

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    Background: World Trade Center (WTC) rescue and recovery workers were exposed to a complex mix of pollutants and carcinogens. Objective: The purpose of this investigation was to evaluate cancer incidence in responders during the first 7 years after 11 September 2001. Methods: Cancers among 20,984 consented participants in the WTC Health Program were identified through linkage to state tumor registries in New York, New Jersey, Connecticut, and Pennsylvania. Standardized incidence ratios (SIRs) were calculated to compare cancers diagnosed in responders to predicted numbers for the general population. Multivariate regression models were used to estimate associations with degree of exposure. Results: A total of 575 cancers were diagnosed in 552 individuals. Increases above registry-based expectations were noted for all cancer sites combined (SIR = 1.15; 95% CI: 1.06, 1.25), thyroid cancer (SIR = 2.39; 95% CI: 1.70, 3.27), prostate cancer (SIR = 1.21; 95% CI: 1.01, 1.44), combined hematopoietic and lymphoid cancers (SIR = 1.36; 95% CI: 1.07, 1.71), and soft tissue cancers (SIR = 2.26; 95% CI: 1.13, 4.05). When restricted to 302 cancers diagnosed ≥ 6 months after enrollment, the SIR for all cancers decreased to 1.06 (95% CI: 0.94, 1.18), but thyroid and prostate cancer diagnoses remained greater than expected. All cancers combined were increased in very highly exposed responders and among those exposed to significant amounts of dust, compared with responders who reported lower levels of exposure. Conclusion: Estimates should be interpreted with caution given the short follow-up and long latency period for most cancers, the intensive medical surveillance of this cohort, and the small numbers of cancers at specific sites. However, our findings highlight the need for continued follow-up and surveillance of WTC responders
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