220 research outputs found
Growth restriction in gastroschisis: quantification of its severity and exploration of a placental cause
<p>Abstract</p> <p>Background</p> <p>Gastroschisis patients are commonly small for gestational age (SGA, birth weight [BW] < 10<sup>th </sup>centile). However, the extent, symmetry and causes of that growth restriction remain controversial.</p> <p>Methods</p> <p>We compared BW, crown-heel length (LT), occipitofrontal circumference (OFC) and ponderal index (PI) in 179 gastroschisis cases and 895 matched controls by univariate and multiple regression. Fetal ultrasounds (N = 80) were reviewed to determine onset of growth restriction. Placental histology was examined in 31 gastroschisis patients whose placental tissue was available and in 29 controls.</p> <p>Results</p> <p>Gastroschisis cases weighed less than controls (BW = 2400 ± 502 g vs. 2750 ± 532 g, p < 0.001) and their BW frequency curve was shifted to the left, indicating lower BW as a group compared to controls (p < 0.001 by Kolmogorov-Smirnov test). BW differences varied from -148 g at 33 weeks to -616 g at 38 weeks gestation. Intrauterine growth restriction was symmetric with gastroschisis patients having a shorter LT (45.7 ± 3.3 vs. 48.4 ± 2.7 cm, p < 0.001), smaller OFC (31.9 ± 1.9 vs. 32.9 ± 1.6 cm, p < 0.001), but larger ponderal index (2.51 ± 0.37 vs. 2.40 ± 0.16, p < 0.001) compared to controls. Gastroschisis patients had a similar reduction in BW (-312 g, 95% confidence interval [CI] = -367, -258) compared to those with chromosomal abnormalities (-239 g, CI = -292, -187). Growth deficits appeared early in the second trimester and worsened as gestation increased. Placental chorangiosis was more common in gastroschisis patients than controls, even after removing all SGA patients (77% vs. 42%, p = 0.02).</p> <p>Conclusions</p> <p>Marked, relatively symmetric intrauterine growth restriction is an intrinsic part of gastroschisis. It begins early in the second trimester, and is associated with placental chorangiosis.</p
Sansanmycin natural product analogues as potent and selective anti-mycobacterials that inhibit lipid I biosynthesis.
Tuberculosis (TB) is responsible for enormous global morbidity and mortality, and current treatment regimens rely on the use of drugs that have been in use for more than 40 years. Owing to widespread resistance to these therapies, new drugs are desperately needed to control the TB disease burden. Herein, we describe the rapid synthesis of analogues of the sansanmycin uridylpeptide natural products that represent promising new TB drug leads. The compounds exhibit potent and selective inhibition of Mycobacterium tuberculosis, the etiological agent of TB, both in vitro and intracellularly. The natural product analogues were also shown to be nanomolar inhibitors of Mtb phospho-MurNAc-pentapeptide translocase, the enzyme responsible for the synthesis of lipid I in mycobacteria. This work lays the foundation for the development of uridylpeptide natural product analogues as new TB drug candidates that operate through the inhibition of peptidoglycan biosynthesis
Unusual presentation of Lynch Syndrome
Lynch Syndrome/HNPCC is a syndrome of cancer predisposition linked to inherited mutations of genes participating in post-replicative DNA mismatch repair (MMR). The spectrum of cancer associated with Lynch Syndrome includes tumours of the colorectum, endometrium, ovary, upper gastrointestinal tract and the urothelium although other cancers are rarely described. We describe a family of Lynch Syndrome with an hMLH1 mutation, that harbours an unusual tumour spectrum and its diagnostic and management challenges
Gene-Trap Mutagenesis Identifies Mammalian Genes Contributing to Intoxication by Clostridium perfringens ε-Toxin
The Clostridium perfringens ε-toxin is an extremely potent toxin associated with lethal toxemias in domesticated ruminants and may be toxic to humans. Intoxication results in fluid accumulation in various tissues, most notably in the brain and kidneys. Previous studies suggest that the toxin is a pore-forming toxin, leading to dysregulated ion homeostasis and ultimately cell death. However, mammalian host factors that likely contribute to ε-toxin-induced cytotoxicity are poorly understood. A library of insertional mutant Madin Darby canine kidney (MDCK) cells, which are highly susceptible to the lethal affects of ε-toxin, was used to select clones of cells resistant to ε-toxin-induced cytotoxicity. The genes mutated in 9 surviving resistant cell clones were identified. We focused additional experiments on one of the identified genes as a means of validating the experimental approach. Gene expression microarray analysis revealed that one of the identified genes, hepatitis A virus cellular receptor 1 (HAVCR1, KIM-1, TIM1), is more abundantly expressed in human kidney cell lines than it is expressed in human cells known to be resistant to ε-toxin. One human kidney cell line, ACHN, was found to be sensitive to the toxin and expresses a larger isoform of the HAVCR1 protein than the HAVCR1 protein expressed by other, toxin-resistant human kidney cell lines. RNA interference studies in MDCK and in ACHN cells confirmed that HAVCR1 contributes to ε-toxin-induced cytotoxicity. Additionally, ε-toxin was shown to bind to HAVCR1 in vitro. The results of this study indicate that HAVCR1 and the other genes identified through the use of gene-trap mutagenesis and RNA interference strategies represent important targets for investigation of the process by which ε-toxin induces cell death and new targets for potential therapeutic intervention
Evidence for a Prepore Stage in the Action of Clostridium perfringens Epsilon Toxin
Clostridium perfringens epsilon toxin (ETX) rapidly kills MDCK II cells at 37°C, but not 4°C. The current study shows that, in MDCK II cells, ETX binds and forms an oligomeric complex equally well at 37°C and 4°C but only forms a pore at 37°C. However, the complex formed in MDCK cells treated with ETX at 4°C has the potential to form an active pore, since shifting those cells to 37°C results in rapid cytotoxicity. Those results suggested that the block in pore formation at 4°C involves temperature-related trapping of ETX in a prepore intermediate on the MDCK II cell plasma membrane surface. Evidence supporting this hypothesis was obtained when the ETX complex in MDCK II cells was shown to be more susceptible to pronase degradation when formed at 4°C vs. 37°C; this result is consistent with ETX complex formed at 4°C remaining present in an exposed prepore on the membrane surface, while the ETX prepore complex formed at 37°C is unaccessible to pronase because it has inserted into the plasma membrane to form an active pore. In addition, the ETX complex rapidly dissociated from MDCK II cells at 4°C, but not 37°C; this result is consistent with the ETX complex being resistant to dissociation at 37°C because it has inserted into membranes, while the ETX prepore readily dissociates from cells at 4°C because it remains on the membrane surface. These results support the identification of a prepore stage in ETX action and suggest a revised model for ETX cytotoxicity, i) ETX binds to an unidentified receptor, ii) ETX oligomerizes into a prepore on the membrane surface, and iii) the prepore inserts into membranes, in a temperature-sensitive manner, to form an active pore
Evolution of long-term vaccine-induced and hybrid immunity in healthcare workers after different COVID-19 vaccine regimens
BACKGROUND: Both infection and vaccination, alone or in combination, generate antibody and TÂ cell responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the maintenance of such responses-and hence protection from disease-requires careful characterization. In a large prospective study of UK healthcare workers (HCWs) (Protective Immunity from T Cells in Healthcare Workers [PITCH], within the larger SARS-CoV-2 Immunity and Reinfection Evaluation [SIREN] study), we previously observed that prior infection strongly affected subsequent cellular and humoral immunity induced after long and short dosing intervals of BNT162b2 (Pfizer/BioNTech) vaccination. METHODS: Here, we report longer follow-up of 684 HCWs in this cohort over 6-9Â months following two doses of BNT162b2 or AZD1222 (Oxford/AstraZeneca) vaccination and up to 6Â months following a subsequent mRNA booster vaccination. FINDINGS: We make three observations: first, the dynamics of humoral and cellular responses differ; binding and neutralizing antibodies declined, whereas T and memory B cell responses were maintained after the second vaccine dose. Second, vaccine boosting restored immunoglobulin (Ig) G levels; broadened neutralizing activity against variants of concern, including Omicron BA.1, BA.2, and BA.5; and boosted TÂ cell responses above the 6-month level after dose 2. Third, prior infection maintained its impact driving larger and broader TÂ cell responses compared with never-infected people, a feature maintained until 6Â months after the third dose. CONCLUSIONS: Broadly cross-reactive TÂ cell responses are well maintained over time-especially in those with combined vaccine and infection-induced immunity ("hybrid" immunity)-and may contribute to continued protection against severe disease
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Multiple Independent Loci at Chromosome 15q25.1 Affect Smoking Quantity: a Meta-Analysis and Comparison with Lung Cancer and COPD
Recently, genetic association findings for nicotine dependence, smoking behavior, and smoking-related diseases converged to implicate the chromosome 15q25.1 region, which includes the CHRNA5-CHRNA3-CHRNB4 cholinergic nicotinic receptor subunit genes. In particular, association with the nonsynonymous CHRNA5 SNP rs16969968 and correlates has been replicated in several independent studies. Extensive genotyping of this region has suggested additional statistically distinct signals for nicotine dependence, tagged by rs578776 and rs588765. One goal of the Consortium for the Genetic Analysis of Smoking Phenotypes (CGASP) is to elucidate the associations among these markers and dichotomous smoking quantity (heavy versus light smoking), lung cancer, and chronic obstructive pulmonary disease (COPD). We performed a meta-analysis across 34 datasets of European-ancestry subjects, including 38,617 smokers who were assessed for cigarettes-per-day, 7,700 lung cancer cases and 5,914 lung-cancer-free controls (all smokers), and 2,614 COPD cases and 3,568 COPD-free controls (all smokers). We demonstrate statistically independent associations of rs16969968 and rs588765 with smoking (mutually adjusted p-values<10 and <10 respectively). Because the risk alleles at these loci are negatively correlated, their association with smoking is stronger in the joint model than when each SNP is analyzed alone. Rs578776 also demonstrates association with smoking after adjustment for rs16969968 (p<10). In models adjusting for cigarettes-per-day, we confirm the association between rs16969968 and lung cancer (p<10) and observe a nominally significant association with COPD (p = 0.01); the other loci are not significantly associated with either lung cancer or COPD after adjusting for rs16969968. This study provides strong evidence that multiple statistically distinct loci in this region affect smoking behavior. This study is also the first report of association between rs588765 (and correlates) and smoking that achieves genome-wide significance; these SNPs have previously been associated with mRNA levels of CHRNA5 in brain and lung tissue
Beaked whales respond to simulated and actual navy sonar
This article is distributed under the terms of the Creative Commons Public Domain declaration. The definitive version was published in PLoS One 6 (2011): e17009, doi:10.1371/journal.pone.0017009.Beaked whales have mass stranded during some naval sonar exercises, but the cause is unknown. They are difficult to sight but can reliably be detected by listening for echolocation clicks produced during deep foraging dives. Listening for these clicks, we documented Blainville's beaked whales, Mesoplodon densirostris, in a naval underwater range where sonars are in regular use near Andros Island, Bahamas. An array of bottom-mounted hydrophones can detect beaked whales when they click anywhere within the range. We used two complementary methods to investigate behavioral responses of beaked whales to sonar: an opportunistic approach that monitored whale responses to multi-day naval exercises involving tactical mid-frequency sonars, and an experimental approach using playbacks of simulated sonar and control sounds to whales tagged with a device that records sound, movement, and orientation. Here we show that in both exposure conditions beaked whales stopped echolocating during deep foraging dives and moved away. During actual sonar exercises, beaked whales were primarily detected near the periphery of the range, on average 16 km away from the sonar transmissions. Once the exercise stopped, beaked whales gradually filled in the center of the range over 2–3 days. A satellite tagged whale moved outside the range during an exercise, returning over 2–3 days post-exercise. The experimental approach used tags to measure acoustic exposure and behavioral reactions of beaked whales to one controlled exposure each of simulated military sonar, killer whale calls, and band-limited noise. The beaked whales reacted to these three sound playbacks at sound pressure levels below 142 dB re 1 µPa by stopping echolocation followed by unusually long and slow ascents from their foraging dives. The combined results indicate similar disruption of foraging behavior and avoidance by beaked whales in the two different contexts, at exposures well below those used by regulators to define disturbance.The research reported here was financially supported by the United States (U.S.) Office of Naval Research (www.onr.navy.mil) Grants N00014-07-10988,
N00014-07-11023, N00014-08-10990; the U.S. Strategic Environmental Research and Development Program (www.serdp.org) Grant SI-1539, the Environmental
Readiness Division of the U.S. Navy (http://www.navy.mil/local/n45/), the U.S. Chief of Naval Operations Submarine Warfare Division (Undersea Surveillance), the
U.S. National Oceanic and Atmospheric Administration (National Marine Fisheries Service, Office of Science and Technology) (http://www.st.nmfs.noaa.gov/), U.S.
National Oceanic and Atmospheric Administration Ocean Acoustics Program (http://www.nmfs.noaa.gov/pr/acoustics/), and the Joint Industry Program on Sound
and Marine Life of the International Association of Oil and Gas Producers (www.soundandmarinelife.org)
Robot-assisted radical prostatectomy vs laparoscopic and open retropubic radical prostatectomy: functional outcomes 18 months after diagnosis from a national cohort study in England.
BACKGROUND: Robot-assisted radical prostatectomy (RARP) has been rapidly adopted without robust evidence comparing its functional outcomes against laparoscopic radical prostatectomy (LRP) or open retropubic radical prostatectomy (ORP) approaches. This study compared patient-reported functional outcomes following RARP, LRP or ORP. METHODS: All men diagnosed with prostate cancer in England during April - October 2014 who underwent radical prostatectomy were identified from the National Prostate Cancer Audit and mailed a questionnaire 18 months after diagnosis. Group differences in patient-reported sexual, urinary, bowel and hormonal function (EPIC-26 domain scores) and generic health-related quality of life (HRQoL; EQ-5D-5L scores), with adjustment for patient and tumour characteristics, were estimated using linear regression. RESULTS: In all, 2219 men (77.0%) responded; 1310 (59.0%) had RARP, 487 (21.9%) LRP and 422 (19.0%) ORP. RARP was associated with slightly higher adjusted mean EPIC-26 sexual function scores compared with LRP (3·5 point difference; 95% CI: 1.1-5.9, P=0.004) or ORP (4.0 point difference; 95% CI: 1.5-6.5, P=0.002), which did not meet the threshold for a minimal clinically important difference (10-12 points). There were no significant differences in other EPIC-26 domain scores or HRQoL. CONCLUSIONS: It is unlikely that the rapid adoption of RARP in the English NHS has produced substantial improvements in functional outcomes for patients
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