Recessive ACTA1 variant causes congenital muscular dystrophy with rigid spine

Variants in ACTA1, which encodes α-skeletal actin, cause several congenital myopathies, most commonly nemaline myopathy. Autosomal recessive variants comprise approximately 10% of ACTA1 myopathy. All recessive variants reported to date have resulted in loss of skeletal α-actin expression from muscle and severe weakness from birth. Targeted next-generation sequencing in two brothers with congenital muscular dystrophy with rigid spine revealed homozygous missense variants in ACTA1. Skeletal α-actin expression was preserved in these patients. This report expands the clinical and histological phenotype of ACTA1 disease to include congenital muscular dystrophy with rigid spine and dystrophic features on muscle biopsy. This represents a new class of recessive ACTA1 variants, which do not abolish protein expression.     

Facility-based active management of the third stage of labour: assessment of quality in six countries in sub-Saharan Africa

Objective

To assess the quality of facility-based active management of the third stage of labour in Ethiopia, Kenya, Madagascar, Mozambique, Rwanda and the United Republic of Tanzania.

Methods

Between 2009 and 2012, using a cross-sectional design, 2317 women in 390 health facilities were directly observed during the third stage of labour. Observers recorded the use of uterotonic medicines, controlled cord traction and uterine massage. Facility infrastructure and supplies needed for active management were audited and relevant guidelines reviewed.

Findings

Most (94%; 2173) of the women observed were given oxytocin (2043) or another uterotonic (130). The frequencies of controlled cord traction and uterine massage and the timing of uterotonic administration showed considerable between-country variation. Of the women given a uterotonic, 1640 (76%) received it within three minutes of the birth. Uterotonics and related supplies were generally available onsite. Although all of the study countries had national policies and/or guidelines that supported the active management of the third stage of labour, the presence of guidelines in facilities varied across countries and only 377 (36%) of 1037 investigated providers had received relevant training in the previous three years.

Conclusion

In the study countries, quality and coverage of the active management of the third stage of labour were high. However, to improve active management, there needs to be more research on optimizing the timing of uterotonic administration. Training on the use of new clinical guidelines and implementation research on the best methods to update such training are also needed.     

Immunolocalization of Musashi1 and Fibronectin Type III Domain Containing 3B in Water Buffalo Mammary Glands

Water buffaloes are the principle source of milk in south Asia and Africa. Mammary gland repeatedly undergoes the cycles of growth and regeneration during pregnancy, lactation and involution. It is assumed that buffalo mammary gland has mammary stem and progenitor cells that regulate gland growth and regeneration. In the present study the authors analyzed percentage of cellular composition, proliferation status and putative mammary stem/progenitor cell population. Identification of putative buffalo mammary stem/progenitor cells was attempted using immunohistochemical staining with Musashi1 (MSI1), an adult stem cell marker and fibronectin type III domain containing 3B (FNDC3B), a mammary stem and cancer cell marker. Immunolocalization of MSI1 and FNDC3B showed nuclear and cytoplasmic staining of alveolar and ductal mammary epithelial cells (MEC) and a few stromal cells. The percentage of MSI1-positive MEC in non-lactating (3.31 ± 1.11 %), lactating (2.73 ± 0.78 %) and mastitic glands (3.30 ± 0.97 %) were equivalent, indicating that the proportion of putative stem/progenitor cell population did not differ during various physiological stages. Likewise, the percentage of FNDC3B-positive MEC in non-lactating (12.40 ± 3.22 %) tended to be higher than lactating (8.19 ± 2.71 %) and mastitic glands (4.88 ± 2.37 %). In some cases, expression of MSI1 and FNDC3B was exceptionally high with high proliferative indices (37.6 ± 2.4 %)-an indication of tumor cells. This is the first report on expression of MSI1 and FNDC3B in buffalo mammary gland. Identification of buffalo mammary stem cells using MSI1 and FNDC3B requires further studies and functional validation.     

Novel immunosuppressive agent caerulomycin A exerts its effect by depleting cellular iron content

Background and Purpose

Recently, we have described the use of caerulomycin A (CaeA) as a potent novel immunosuppressive agent. Immunosuppressive drugs are crucial for long-term graft survival following organ transplantation and treatment of autoimmune diseases, inflammatory disorders, hypersensitivity to allergens, etc. The objective of this study was to identify cellular targets of CaeA and decipher its mechanism of action.

Experimental Approach

Jurkat cells were treated with CaeA and cellular iron content, iron uptake/release, DNA content and deoxyribonucleoside triphosphate pool determined. Activation of MAPKs; expression level of transferrin receptor 1, ferritin and cell cycle control molecules; reactive oxygen species (ROS) and cell viability were measured using Western blotting, qRT-PCR or flow cytometry.

Key Results

CaeA caused intracellular iron depletion by reducing its uptake and increasing its release by cells. CaeA caused cell cycle arrest by (i) inhibiting ribonucleotide reductase (RNR) enzyme, which catalyses the rate-limiting step in the synthesis of DNA; (ii) stimulating MAPKs signalling transduction pathways that play an important role in cell growth, proliferation and differentiation; and (iii) by targeting cell cycle control molecules such as cyclin D1, cyclin-dependent kinase 4 and p21^CIP1/WAF1. The effect of CaeA on cell proliferation was reversible.

Conclusions and Implications

CaeA exerts its immunosuppressive effect by targeting iron. The effect is reversible, which makes CaeA an attractive candidate for development as a potent immunosuppressive drug, but also indicates that iron chelation can be used as a rationale approach to selectively suppress the immune system, because compared with normal cells, rapidly proliferating cells require a higher utilization of iron.     

Emerging role of non‐coding RNA in health and disease

Metabolic Brain Disease - Human diseases have always been a significant turf of concern since the origin of mankind. It is cardinal to know the cause, treatment, and cure for every disease...     

Pathophysiology,Diagnosis, and Management of Coronary No-Reflow Phenomenon

Coronary no-reflow phenomenon is a lethal mechanism of ongoing myocardial injury, following successful revascularization of an infarct-related coronary artery. Incidence of this phenomenon is high following percutaneous intervention, and is associated with adverse in-hospital and long-term outcomes. Several mechanisms such as ischemia-reperfusion injury and distal microthromboembolism in genetically susceptible patients and those with preexisting endothelial dysfunction have been implicated. However, the exact mechanism in humans is still poorly understood. Several investigative and treatment strategies within and outside the cardiac catheterization laboratory have been proposed, but have not uniformly shown success in reducing mortality or in preventing adverse left ventricular remodeling resulting from this condition. The aim of this article is to provide a brief and concise review of the current understanding of the pathophysiology, clinical predictors, and investigations and management of coronary no-reflow phenomenon.     

Chronic Obstructive Pulmonary Disease and its Non-Smoking Risk Factors in India

The rising prevalence of the chronic obstructive pulmonary disease (COPD) is generally attributed to smoking, since the role of other risk factors among non-smokers are not well established especially in low and middle income countries like India. This is also reflected by the limited literature available on non-smoking related COPD risk factors like indoor and outdoor air pollution. The present review is an attempt to assess the influence of non-smoking risk factors on COPD and its measures in Indian subcontinent. The most noteworthy factors among non-smokers appear to be the use of biomass fuel for cooking and heating purposes. We observed that the studies undertaken to evaluate the role of such risk factors are inconclusive due to weak methodologies and small sample sizes, may be due to limited financial resources. The present review suggests the need of a nationally representative study to estimate the effect of each of the potential modifiable risk factor (other than smoking) for framing impactful public health policies to prevent and manage COPD at community and population level in India.     

Enrichment for murine keratinocyte stem cells based on cell surface phenotype

The identification and physical isolation of epithelial stem cells is critical to our understanding of their growth regulation during homeostasis, wound healing, and carcinogenesis. These stem cells remain poorly characterized because of the absence of specific molecular markers that permit us to distinguish them from their progeny, the transit amplifying (TA) cells, which have a more restricted proliferative potential. Cell kinetic analyses have permitted the identification of murine keratinocyte stem cells (KSCs) as slowly cycling cells that retain [(3)H]thymidine ([(3)H]Tdr) label, termed label-retaining cells (LRCs), whereas TA cells are visualized as rapidly cycling cells after a single pulse of [(3)H]Tdr, termed pulse-labeled cells (PLCs). Here, we report on the successful separation of KSCs from TA cells through the combined use of in vivo cell kinetic analysis and fluorescence-activated cell sorting. Specifically, we demonstrate that murine dorsal keratinocytes characterized by their high levels of alpha(6) integrin and low to undetectable expression of the transferrin receptor (CD71) termed alpha(6)(bri)CD71(dim) cells, are enriched for epithelial stem cells because they represent a minor ( approximately 8%) and quiescent subpopulation of small blast-like cells, with a high nuclear:cytoplasmic ratio, containing approximately 70% of label-retaining cells, the latter being a well documented characteristic of stem cells. Conversely, TA cells could be enriched in a phenotypically distinct subpopulation termed alpha(6)(bri)CD71(bri), representing the majority ( approximately 60%) of basal keratinocytes that are actively cycling, and importantly contain approximately 70% of [(3)H]Tdr pulse-labeled cells. Importantly, immunostaining of dorsal skin revealed the presence of CD71(dim) cells in the hair follicle bulge region, a well documented location for KSCs.