754 research outputs found

    Reply to Dr. Lai regarding Allopurinol Hypersensitivity Syndrome in patients of Asian ancestry

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    We thank Dr Lai for their interest in our study (1). While we did not show a statistically significant link between the use of allopurinol and mortality in people with gout, we agree that Allopurinol Hypersensitivity Syndrome (AHS) is the most serious side-effect of allopurinol, particularly in populations with South East Asian ancestry, leading to the recommendation to screen people of South East Asian descent for the HLA-B*5801 allele prior to starting treatment with allopurinol (2,3)

    Estimating internationally imported cases during the early COVID-19 pandemic

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    Early in the COVID-19 pandemic, predictions of international outbreaks were largely based on imported cases from Wuhan, China, potentially missing imports from other cities. We provide a method, combining daily COVID-19 prevalence and flight passenger volume, to estimate importations from 18 Chinese cities to 43 international destinations, including 26 in Africa. Global case importations from China in early January came primarily from Wuhan, but the inferred source shifted to other cities in mid-February, especially for importations to African destinations. We estimate that 10.4 (6.2 - 27.1) COVID-19 cases were imported to these African destinations, which exhibited marked variation in their magnitude and main sources of importation. We estimate that 90% of imported cases arrived between 17 January and 7 February, prior to the first case detections. Our results highlight the dynamic role of source locations, which can help focus surveillance and response efforts

    Non-treatment of children with community health worker-diagnosed fast-breathing pneumonia in rural Malawi: exploratory subanalysis of a prospective cohort study

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    BACKGROUND: Despite recent progress, pneumonia remains the largest infectious killer of children globally. This paper describes outcomes of not treating community-diagnosed fast-breathing pneumonia on patient recovery. METHODS: We conducted an exploratory subanalysis of an observational prospective cohort study in Malawi. We recruited children (2-59 months) diagnosed by community health workers with fast-breathing pneumonia using WHO integrated community case management (iCCM) guidelines. Children were followed at days 5 and 14 with a clinical assessment of recovery. We conducted bivariate and multivariable logistic regression for the association between treatment of fast-breathing pneumonia and recovery, adjusting for potential confounders. RESULTS: We followed up 847 children, of whom 78 (9%) had not been given antibiotics (non-treatment). Non-treatment cases had higher baseline rates of diarrhoea, non-severe hypoxaemia and fever. Non-recovery (persistence or worsening of symptoms) was 13% and 23% at day 5 in those who did receive and those who did not receive co-trimoxazole. Non-recovery, when defined as worsening of symptoms only, at day 5 was 7% in treatment and 10% in non-treatment cases. For both definitions, combined co-trimoxazole and lumefantrine-artemether (LA) treatment trended towards protection (adjusted OR (aOR) 0.28; 95% CI 0.12 to 0.68/aOR 0.29; 95% CI 0.08 to 1.01). CONCLUSION: We found that children who did not receive co-trimoxazole treatment had worse clinical outcomes; malaria co-diagnosis and treatment also play a significant role in non-recovery. Further research into non-treatment of fast-breathing pneumonia, using a pragmatic approach with consideration for malaria co-diagnosis and HIV status is needed to guide refinement of community treatment algorithms in this region

    Multiple reassortment events in the evolutionary history of H1N1 influenza A virus since 1918

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    The H1N1 subtype of influenza A virus has caused substantial morbidity and mortality in humans, first documented in the global pandemic of 1918 and continuing to the present day. Despite this disease burden, the evolutionary history of the A/H1N1 virus is not well understood, particularly whether there is a virological basis for several notable epidemics of unusual severity in the 1940s and 1950s. Using a data set of 71 representative complete genome sequences sampled between 1918 and 2006, we show that segmental reassortment has played an important role in the genomic evolution of A/H1N1 since 1918. Specifically, we demonstrate that an A/H1N1 isolate from the 1947 epidemic acquired novel PB2 and HA genes through intra-subtype reassortment, which may explain the abrupt antigenic evolution of this virus. Similarly, the 1951 influenza epidemic may also have been associated with reassortant A/H1N1 viruses. Intra-subtype reassortment therefore appears to be a more important process in the evolution and epidemiology of H1N1 influenza A virus than previously realized

    Evaluation of Lay Support in Pregnant women with Social risk (ELSIPS): a randomised controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Maternal, neonatal and child health outcomes are worse in families from black and ethnic minority groups and disadvantaged backgrounds. There is little evidence on whether lay support improves maternal and infant outcomes among women with complex social needs within a disadvantaged multi-ethnic population in the United Kingdom (UK).</p> <p>Method/Design</p> <p>The aim of this study is to evaluate a lay Pregnancy Outreach Worker (POW) service for nulliparous women identified as having social risk within a maternity service that is systematically assessing social risks alongside the usual obstetric and medical risks. The study design is a randomised controlled trial (RCT) in nulliparous women assessed as having social risk comparing standard maternity care with the addition of referral to the POW support service.</p> <p>The POWs work alongside community midwifery teams and offer individualised support to women to encourage engagement with services (health and social care) from randomisation (before 28 weeks gestation) until 6 weeks after birth.</p> <p>The primary outcomes have been chosen on the basis that they are linked to maternal and infant health. The two primary outcomes are engagement with antenatal care, assessed by the number of antenatal visits; and maternal depression, assessed using the Edinburgh Postnatal Depression Scale at 8-12 weeks after birth. Secondary outcomes include maternal and neonatal morbidity and mortality, routine child health assessments, including immunisation uptake and breastfeeding at 6 weeks. Other psychological outcomes (self efficacy) and mother-to-infant bonding will also be collected using validated tools.</p> <p>A sample size of 1316 will provide 90% power (at the 5% significance level) to detect increased engagement with antenatal services of 1.5 visits and a reduction of 1.5 in the average EPDS score for women with two or more social risk factors, with power in excess of this for women with any social risk factor. Analysis will be by intention to treat.</p> <p>Qualitative research will explore the POWs' daily work in context. This will complement the findings of the RCT through a triangulation of quantitative and qualitative data on the process of the intervention, and identify other contextual factors that affect the implementation of the intervention.</p> <p>Discussion</p> <p>The trial will provide high quality evidence as to whether or not lay support (POW) offered to women identified with social risk factors improves engagement with maternity services and reduces numbers of women with depression.</p> <p>MREC number</p> <p>10/H1207/23</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN35027323">ISRCTN35027323</a></p

    Patient-centric trials for therapeutic development in precision oncology

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    An enhanced understanding of the molecular pathology of disease gained from genomic studies is facilitating the development of treatments that target discrete molecular subclasses of tumours. Considerable associated challenges include how to advance and implement targeted drug-development strategies. Precision medicine centres on delivering the most appropriate therapy to a patient on the basis of clinical and molecular features of their disease. The development of therapeutic agents that target molecular mechanisms is driving innovation in clinical-trial strategies. Although progress has been made, modifications to existing core paradigms in oncology drug development will be required to realize fully the promise of precision medicine

    Molecular mechanisms in uterine epithelium during trophoblast binding: the role of small GTPase RhoA in human uterine Ishikawa cells

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    BACKGROUND: Embryo implantation requires that uterine epithelium develops competence to bind trophoblast to its apical (free) poles. This essential element of uterine receptivity seems to depend on a destabilisation of the apico-basal polarity of endometrial epithelium. Accordingly, a reorganisation of the actin cytoskeleton regulated by the small GTPase RhoA plays an important role in human uterine epithelial RL95-2 cells for binding of human trophoblastoid JAR cells. We now obtained new insight into trophoblast binding using human uterine epithelial Ishikawa cells. METHODS: Polarity of Ishikawa cells was investigated by electron microscopy, apical adhesiveness was tested by adhesion assay. Analyses of subcellular distribution of filamentous actin (F-actin) and RhoA in apical and basal cell poles were performed by confocal laser scanning microscopy (CLSM) with and without binding of JAR spheroids as well as with and without inhibition of small Rho GTPases by Clostridium difficile toxin A (toxin A). In the latter case, subcellular distribution of RhoA was additionally investigated by Western blotting. RESULTS: Ishikawa cells express apical adhesiveness for JAR spheroids and moderate apico-basal polarity. Without contact to JAR spheroids, significantly higher signalling intensities of F-actin and RhoA were found at the basal as compared to the apical poles in Ishikawa cells. RhoA was equally distributed between the membrane fraction and the cytosol fraction. Levels of F-actin and RhoA signals became equalised in the apical and basal regions upon contact to JAR spheroids. After inhibition of Rho GTPases, Ishikawa cells remained adhesive for JAR spheroids, the gradient of fluorescence signals of F-actin and RhoA was maintained while the amount of RhoA was reduced in the cytosolic fraction with a comparable increase in the membrane fraction. CONCLUSION: Ishikawa cells respond to JAR contact as well as to treatment with toxin A with rearrangement of F-actin and small GTPase RhoA but seem to be able to modify signalling pathways in a way not elucidated so far in endometrial cells. This ability may be linked to the degree of polar organisation observed in Ishikawa cells indicating an essential role of cell phenotype modification in apical adhesiveness of uterine epithelium for trophoblast in vivo

    TGFbeta induces apoptosis and EMT in primary mouse hepatocytes independently of p53, p21Cip1 or Rb status

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    Melville Trust for the Care and Cure of Cancer to SP and SS.Background: TGF beta has pleiotropic effects that range from regulation of proliferation and apoptosis to morphological changes and epithelial-mesenchymal transition (EMT). Some evidence suggests that these effects may be interconnected. We have recently reported that P53, P21(Cip1) and pRB, three critical regulators of the G1/S transition are variably involved in TGF beta-induced cell cycle arrest in hepatocytes. As these proteins are also involved in the regulation of apoptosis in many circumstances, we investigated their contribution to other relevant TGF beta-induced effects, namely apoptosis and EMT, and examined how the various processes were interrelated. Methods: Primary mouse hepatocytes deficient in p53, p21 and/or Rb, singly or in combination were treated with TGF beta for 24 to 96 hours. Apoptosis was quantified according to morphology and by immunostaining for cleavedcapsase 3. Epithelial and mesenchymal marker expression was studied using immunocytochemistry and real time PCR. Results: We found that TGF beta similarly induced morphological changes regardless of genotype and independently of proliferation index or sensitivity to inhibition of proliferation by TGF beta. Morphological changes were accompanied by decrease in E-cadherin and increased Snail expression but the mesenchymal markers (N-cadherin, SMA alpha and Vimentin) studied remained unchanged. TGF beta induced high levels of apoptosis in p53-/-, Rb-/-, p21(cip1)-/- and control hepatocytes although with slight differences in kinetics. This was unrelated to proliferation or changes in morphology and loss of cell-cell adhesion. However, hepatocytes deficient in both p53 and p21(cip1)were less sensitive to TGF beta-induced apoptosis. Conclusion: Although p53, p21(Cip1) and pRb are well known regulators of both proliferation and apoptosis in response to a multitude of stresses, we conclude that they are critical for TGF beta-driven inhibition of hepatocytes proliferation, but only slightly modulate TGF beta-induced apoptosis. This effect may depend on other parameters such as proliferation and the presence of other regulatory proteins as suggested by the consequences of p53, p21(Cip1) double deficiency. Similarly, p53, p21(Cip1) and pRB deficiency had no effect on the morphological changes and loss of cell adhesion which is thought to be critical for metastasis. This indicates that possible association of these genes with metastasis potential would be unlikely to involve TGF beta-induced EMT.Publisher PDFPeer reviewe

    Regulation of mammary gland branching morphogenesis by the extracellular matrix and its remodeling enzymes.

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    A considerable body of research indicates that mammary gland branching morphogenesis is dependent, in part, on the extracellular matrix (ECM), ECM-receptors, such as integrins and other ECM receptors, and ECM-degrading enzymes, including matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). There is some evidence that these ECM cues affect one or more of the following processes: cell survival, polarity, proliferation, differentiation, adhesion, and migration. Both three-dimensional culture models and genetic manipulations of the mouse mammary gland have been used to study the signaling pathways that affect these processes. However, the precise mechanisms of ECM-directed mammary morphogenesis are not well understood. Mammary morphogenesis involves epithelial 'invasion' of adipose tissue, a process akin to invasion by breast cancer cells, although the former is a highly regulated developmental process. How these morphogenic pathways are integrated in the normal gland and how they become dysregulated and subverted in the progression of breast cancer also remain largely unanswered questions

    Cancer cell differentiation heterogeneity and aggressive behavior in solid tumors

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    The differentiation stage of tumors is a central aspect in the histopathological classification of solid malignancies. The differentiation stage is strongly associated with tumor behavior, and generally an immature tumor is more aggressive than the more differentiated counterpart. While this is common knowledge in surgical pathology, the contribution of differentiation-related gene expression and functions to tumor behavior is often overlooked in the experimental, tumor biological setting. The mechanisms by which tumor cell differentiation stages are perturbed or affected are poorly explored but have recently come into focus with the introduction.of the tumor stem cell concept. While developmental biologists view the differentiation as a unidirectional event, pathologists and tumor biologists have introduced the concept of dedifferentiation to explain phenotypic changes occurring in solid tumors. In this review we discuss the impact of the tumor cell differentiation stage as used in surgical pathology. We further discuss knowledge gained from exploring the molecular basis of the differentiation and dedifferentiation processes in neuroblastoma and breast cancer, two tumor forms where the tumor cell differentiation concept is used in the clinical diagnostic work and where the tumor stem cell theory has been applied
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