Mena/VASP and αII-Spectrin complexes regulate cytoplasmic actin networks in cardiomyocytes and protect from conduction abnormalities and dilated cardiomyopathy

BACKGROUND: In the heart, cytoplasmic actin networks are thought to have important roles in mechanical support, myofibrillogenesis, and ion channel function. However, subcellular localization of cytoplasmic actin isoforms and proteins involved in the modulation of the cytoplasmic actin networks are elusive. Mena and VASP are important regulators of actin dynamics. Due to the lethal phenotype of mice with combined deficiency in Mena and VASP, however, distinct cardiac roles of the proteins remain speculative. In the present study, we analyzed the physiological functions of Mena and VASP in the heart and also investigated the role of the proteins in the organization of cytoplasmic actin networks. RESULTS: We generated a mouse model, which simultaneously lacks Mena and VASP in the heart. Mena/VASP double-deficiency induced dilated cardiomyopathy and conduction abnormalities. In wild-type mice, Mena and VASP specifically interacted with a distinct αII-Spectrin splice variant (SH3i), which is in cardiomyocytes exclusively localized at Z- and intercalated discs. At Z- and intercalated discs, Mena and β-actin localized to the edges of the sarcomeres, where the thin filaments are anchored. In Mena/VASP double-deficient mice, β-actin networks were disrupted and the integrity of Z- and intercalated discs was markedly impaired. CONCLUSIONS: Together, our data suggest that Mena, VASP, and αII-Spectrin assemble cardiac multi-protein complexes, which regulate cytoplasmic actin networks. Conversely, Mena/VASP deficiency results in disrupted β-actin assembly, Z- and intercalated disc malformation, and induces dilated cardiomyopathy and conduction abnormalities

Mutation analysis of BRCA1 and BRCA2 genes in Iranian high risk breast cancer families

Background: Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal stability leading to cellular immortalization. Telomerase has been associated with negative prognostic indicators in some studies. The present study aims to detect any association between telomerase sub-units: hTERT and hTR and the prognostic indicators including tumour's size and grade, nodal status and patient's age. Methods: Tumour samples from 46 patients with primary invasive breast cancer and 3 patients with benign tumours were collected. RT-PCR analysis was used for the detection of hTR, hTERT, and PGM1 (as a housekeeping) genes expression. Results: The expression of hTR and hTERT was found in 31(67.4%) and 38 (82.6%) samples respectively. We observed a significant association between hTR gene expression and younger age at diagnosis (p = 0.019) when comparing patients ≤ 40 years with those who are older than 40 years. None of the benign tumours expressed hTR gene. However, the expression of hTERT gene was revealed in 2 samples. No significant association between hTR and hTERT expression and tumour's grade, stage and nodal status was seen. Conclusion: The expression of hTR and hTERT seems to be independent of tumour's stage. hTR expression probably plays a greater role in mammary tumourogenesis in younger women (≤ 40 years) and this may have therapeutic implications in the context of hTR targeting strategies

Nutritional status and disease severity in children acutely presenting to a primary health clinic in rural Gambia

BACKGROUND: Accurate and timely data on the health of a population are key for evidence-based decision making at both the policy and programmatic level. In many low-income settings, such data are unavailable or outdated. Using an electronic medical records system, we determined the association between nutritional status and severe illness and mortality among young children presenting to a rural primary health care facility in the Gambia. METHODS: Clinical data collected over five years (2010-2014) on children aged under 60 months making acute visits to a primary health care clinic in the rural Gambian district of Kiang West were retrospectively extracted from the medical records system. Generalised estimating equation models were used to investigate associations between nutritional status and illness severity, accounting for repeat visits, gender, age and access to transport to the clinic. The Population Attributable Fraction (PAF) was used to determine the proportion of severe illness likely attributable to different grades of malnutrition. RESULTS: 3839/5021 (77%) children under 60 months of age living in Kiang West presented acutely to the clinic at least once, yielding 21,278 visits (47% girls, median age 20.2 months (Interquartile Range (IQR) 23.92 months)) and 26,001 diagnoses, 86% being infectious diseases. Severe illness was seen in 4.5% of visits (961/21,278). Wasting was associated with an increased risk of severe illness in a dose-dependent manner, ('WHZ < -1' adjusted Odds Ratio (aOR) 1.68, 95% CI:1.43-1.98, p < 0.001, 'WHZ <-2 and ≥-3' aOR 2.78, 95% CI:2.31-3.36, p < 0.001 and 'WHZ < -3' aOR 7.82, 95% CI:6.40-9.55, p < 0.001) the PAF for wasting (WHZ < -2) was 0.21 (95% CI: 0.18-0.24). Stunting, even in the most severe form (HAZ < -3), was not significantly associated with severe illness (aOR 1.19 95% CI:0.94-1.51) but was associated with a significantly increased risk of death (aOR 6.04 95% CI:1.94-18.78). CONCLUSION: In this population-based cohort of young children in rural Gambia, wasting was associated with disease severity in a dose-dependent manner. Further research is needed into strategies to identify and reach these children with effective interventions to improve their nutritional status

Validation of the Emergency Department-Paediatric Early Warning Score (ED-PEWS) for use in low- and middle-income countries:A multicentre observational study

Early recognition of children at risk of serious illness is essential in preventing morbidity and mortality, particularly in low- and middle-income countries (LMICs). This study aimed to validate the Emergency Department-Paediatric Early Warning Score (ED-PEWS) for use in acute care settings in LMICs. This observational study is based on previously collected clinical data from consecutive children attending four diverse settings in LMICs. Inclusion criteria and study periods (2010–2021) varied. We simulated the ED-PEWS, consisting of patient age, consciousness, work of breathing, respiratory rate, oxygen saturation, heart rate, and capillary refill time, based on the first available parameters. Discrimination was assessed by the area under the curve (AUC), sensitivity and specificity (previously defined cut-offs &lt; 6 and ≥ 15). The outcome measure was for each setting a composite marker of high urgency. 41,917 visits from Gambia rural, 501 visits from Gambia urban, 2,608 visits from Suriname, and 1,682 visits from Tanzania were included. The proportion of high urgency was variable (range 4.6% to 24.9%). Performance ranged from AUC 0.80 (95%CI 0.70–0.89) in Gambia urban to 0.62 (95%CI 0.55–0.67) in Tanzania. The low-urgency cut-off showed a high sensitivity in all settings ranging from 0.83 (95%CI 0.81–0.84) to 1.00 (95%CI 0.97–1.00). The high-urgency cut-off showed a specificity ranging from 0.71 (95%CI 0.66–0.75) to 0.97 (95%CI 0.97–0.97). The ED-PEWS has a moderate to good performance for the recognition of high urgency children in these LMIC settings. The performance appears to have potential in improving the identification of high urgency children in LMICs.</p

Pancreatic alpha cell mass in European subjects with type 2 diabetes

AIMS/HYPOTHESIS: Type 2 diabetes is a bi-hormonal disease characterised by relative hypoinsulinaemia and hyperglucagonaemia with elevated blood glucose levels. Besides pancreatic beta cell defects, a low number of beta cells (low beta cell mass) may contribute to the insufficient secretion of insulin. In this study our aim was to determine whether the alpha cell mass is also altered. METHODS: Using a point counting method, we measured the ratio of alpha to beta cell areas in pancreas samples obtained at autopsy from 50 type 2 diabetic subjects, whose beta cell mass had previously been found to be 36% lower than that of 52 non-diabetic subjects. RESULTS: The topography of alpha and beta cells was similar in both groups: many alpha cells were localised in the centre of the islets and the ratio of alpha/beta cell areas increased with islet size. The average ratio was significantly higher in type 2 diabetic subjects (0.72) than in non-diabetic subjects (0.42), with, however, a large overlap between the two groups. In contrast, the alpha cell mass was virtually identical in type 2 diabetic subjects (366 mg) and non-diabetic subjects (342 mg), and was not influenced by sex, BMI or type of diabetes treatment. CONCLUSIONS: The higher proportion of alpha to beta cells in the islets of some type 2 diabetic subjects is due to a decrease in beta cell number rather than an increase in alpha cell number. This imbalance may contribute to alterations in the normal inhibitory influence exerted by beta cells on alpha cells, and lead to the relative hyperglucagonaemia observed in type 2 diabete

Allograft rejection is associated with development of functional IgE specific for donor MHC antigens.

BACKGROUND: Donor-specific antibodies of the IgG isotype are measured routinely for diagnostic purposes in renal transplant recipients and are associated with antibody-mediated rejection and long-term graft loss. OBJECTIVE: This study aimed to investigate whether MHC-specific antibodies of the IgE isotype are induced during allograft rejection. METHODS: Anti-MHC/HLA IgE levels were measured in sera of mice grafted with skin or heart transplants from various donor strains and in sera of kidney transplant patients with high levels of HLA IgG. Mediator release was triggered in vitro by stimulating basophils that were coated with murine or human IgE-positive serum, respectively, with specific recombinant MHC/HLA antigens. Kidney tissue samples obtained from organ donors were analyzed by using flow cytometry for cells expressing the high-affinity receptor for IgE (FcεRI). RESULTS: Donor MHC class I- and MHC class II-specific IgE was found on acute rejection of skin and heart grafts in several murine strain combinations, as well as during chronic antibody-mediated heart graft rejection. Anti-HLA IgE, including donor HLA class I and II specificities, was identified in a group of sensitized transplant recipients. Murine and human anti-MHC/HLA IgE triggered mediator release in coated basophils on stimulation with specific MHC/HLA antigens. HLA-specific IgE was not linked to atopy, and allergen-specific IgE present in allergic patients did not cross-react with HLA antigens. FcεRI+ cells were found in the human renal cortex and medulla and provide targets for HLA-specific IgE. CONCLUSION: These results demonstrate that MHC/HLA-specific IgE develops during an alloresponse and is functional in mediating effector mechanisms

The Impact of Delayed Treatment of Uncomplicated \u3ci\u3eP. falciparum\u3c/i\u3e Malaria on Progression to Severe Malaria: A Systematic Review and a Pooled Multicentre Individual-Patient Meta-Analysis

BACKGROUND: Delay in receiving treatment for uncomplicated malaria (UM) is often reported to increase the risk of developing severe malaria (SM), but access to treatment remains low in most high-burden areas. Understanding the contribution of treatment delay on progression to severe disease is critical to determine how quickly patients need to receive treatment and to quantify the impact of widely implemented treatment interventions, such as \u27test-and-treat\u27 policies administered by community health workers (CHWs). We conducted a pooled individual-participant meta-analysis to estimate the association between treatment delay and presenting with SM. METHODS AND FINDINGS: A search using Ovid MEDLINE and Embase was initially conducted to identify studies on severe Plasmodium falciparum malaria that included information on treatment delay, such as fever duration (inception to 22nd September 2017). Studies identified included 5 case-control and 8 other observational clinical studies of SM and UM cases. Risk of bias was assessed using the Newcastle-Ottawa scale, and all studies were ranked as \u27Good\u27, scoring ≥7/10. Individual-patient data (IPD) were pooled from 13 studies of 3,989 (94.1% aged \u3c15 years) SM patients and 5,780 (79.6% aged \u3c15 years) UM cases in Benin, Malaysia, Mozambique, Tanzania, The Gambia, Uganda, Yemen, and Zambia. Definitions of SM were standardised across studies to compare treatment delay in patients with UM and different SM phenotypes using age-adjusted mixed-effects regression. The odds of any SM phenotype were significantly higher in children with longer delays between initial symptoms and arrival at the health facility (odds ratio [OR] = 1.33, 95% CI: 1.07-1.64 for a delay of \u3e24 hours versus ≤24 hours; p = 0.009). Reported illness duration was a strong predictor of presenting with severe malarial anaemia (SMA) in children, with an OR of 2.79 (95% CI:1.92-4.06; p \u3c 0.001) for a delay of 2-3 days and 5.46 (95% CI: 3.49-8.53; p \u3c 0.001) for a delay of \u3e7 days, compared with receiving treatment within 24 hours from symptom onset. We estimate that 42.8% of childhood SMA cases and 48.5% of adult SMA cases in the study areas would have been averted if all individuals were able to access treatment within the first day of symptom onset, if the association is fully causal. In studies specifically recording onset of nonsevere symptoms, long treatment delay was moderately associated with other SM phenotypes (OR [95% CI] \u3e3 to ≤4 days versus ≤24 hours: cerebral malaria [CM] = 2.42 [1.24-4.72], p = 0.01; respiratory distress syndrome [RDS] = 4.09 [1.70-9.82], p = 0.002). In addition to unmeasured confounding, which is commonly present in observational studies, a key limitation is that many severe cases and deaths occur outside healthcare facilities in endemic countries, where the effect of delayed or no treatment is difficult to quantify. CONCLUSIONS: Our results quantify the relationship between rapid access to treatment and reduced risk of severe disease, which was particularly strong for SMA. There was some evidence to suggest that progression to other severe phenotypes may also be prevented by prompt treatment, though the association was not as strong, which may be explained by potential selection bias, sample size issues, or a difference in underlying pathology. These findings may help assess the impact of interventions that improve access to treatment