Littoral cell angioma: An incidental finding in a traumatic spleen

Littoral cell angioma (LCA) of the spleen, a rare vascular tumor, is usually asymptomatic, often discovered incidentally and a majority of them are benign in nature. A 20-year-old boy with a history of blunt abdominal trauma, who underwent splenectomy showed the presence of a capsular tear and variegated outer surface on gross examination of the spleen. On the cut section, multiple nodular areas with areas of hemorrhage were noted. Microscopical examination revealed the proliferation of anastomosing, irregular, tortuous blood-filled channels with plenty of histiocytes in the splenic tissue and extensive areas of hemorrhage, inflammatory cell infiltration, and fibrinoid deposits. Immunohistochemistry revealed positivity for CD31 (endothelial differentiation), CD68, and lysozyme (histiocytic differentiation) but was negative for CD34. The final diagnosis was LCA in a case of ruptured spleen after ruling out angiosarcoma. The possibility of this benign entity to have contributed to the potentially fatal splenic injury cannot be overlooked

Chloroquine as weekly chemoprophylaxis or intermittent treatment to prevent malaria in pregnancy in Malawi: a randomised controlled trial.

BACKGROUND: Sulfadoxine-pyrimethamine resistance threatens efficacy of intermittent preventive treatment of malaria during pregnancy, and alternative regimens need to be identified. With the return of chloroquine efficacy in southern Africa, we postulated that chloroquine either as an intermittent therapy or as weekly chemoprophylaxis would be more efficacious than intermittent sulfadoxine-pyrimethamine for prevention of malaria in pregnancy and associated maternal and newborn adverse outcomes. METHODS: We did an open-label, single-centre, randomised controlled trial at Ndirande Health Centre, Blantyre, in southern Malawi. We enrolled pregnant women (first or second pregnancy) at 20-28 weeks' gestation who were HIV negative. Participants were randomly assigned in a 1:1:1 ratio using a computer-generated list to either intermittent sulfadoxine-pyrimethamine (two doses of 1500 mg sulfadoxine and 75 mg pyrimethamine, 4 weeks apart), intermittent chloroquine (two doses of 600 mg on day 1, 600 mg on day 2, and 300 mg on day 3), or chloroquine prophylaxis (600 mg on day 1 then 300 mg every week). The primary endpoint was placental malaria in the modified intent-to-treat population, which consisted of participants who contributed placental histopathology data at birth. Secondary outcomes included clinical malaria, maternal anaemia, low birthweight, and safety. This trial is registered with ClinicalTrials.gov, number NCT01443130. FINDINGS: Between February, 2012, and May, 2014, we enrolled and randomly allocated 900 women, of whom 765 contributed histopathological data and were included in the primary analysis. 108 (14%) women had placental malaria, which was lower than the anticipated prevalence of placental malaria infection. Protection from placental malaria was not improved by chloroquine as either prophylaxis (30 [12%] of 259 had positive histopathology; relative risk [RR] 0·75, 95% CI 0·48-1·17) or intermittent therapy (39 [15%] of 253; RR 1·00, 0·67-1·50) compared with intermittent sulfadoxine-pyrimethamine (39 [15%] of 253). In protocol-specified analyses adjusted for maternal age, gestational age at enrolment, bednet use the night before enrolment, anaemia at enrolment, and malaria infection at enrolment, women taking chloroquine as prophylaxis had 34% lower placental infections than did those allocated intermittent sulfadoxine-pyrimethamine (RR 0·66, 95% CI 0·46-0·95). Clinical malaria was reported in nine women assigned intermittent sulfadoxine-pyrimethamine, four allocated intermittent chloroquine (p=0·26), and two allocated chloroquine prophylaxis (p=0·063). Maternal anaemia was noted in five women assigned intermittent sulfadoxine-pyrimethamine, 15 allocated intermittent chloroquine (p=0·038), and six assigned chloroquine prophylaxis (p>0·99). Low birthweight was recorded for 31 babies born to women allocated intermittent sulfadoxine-pyrimethamine, 29 assigned intermittent chloroquine (p=0·78), and 41 allocated chloroquine prophylaxis (p=0·28). Four women assigned intermittent sulfadoxine-pyrimethamine had adverse events possibly related to study product compared with 94 women allocated intermittent chloroquine (p<0·0001) and 26 allocated chloroquine prophylaxis (p<0·0001). Three women had severe or life-threatening adverse events related to study product, of whom all were assigned intermittent chloroquine (p=0·25). INTERPRETATION: Chloroquine administered as intermittent therapy did not provide better protection from malaria and related adverse effects compared with intermittent sulfadoxine-pyrimethamine in a setting of high resistance to sulfadoxine-pyrimethamine. Chloroquine chemoprophylaxis might provide benefit in protecting against malaria during pregnancy, but studies with larger sample sizes are needed to confirm these results. FUNDING: US National Institutes of Health

DRY COOLING IN SOLAR THERMAL POWER PLANTS

ABSTRACT: The purpose of this study is to evaluate the performance metrics of a solar thermal power plant with dry cooling and further implement a method to increase the cycle efficiency, using passive cooling techniques within the dry cooling cycle. Current methods implementing dry cooled condensation use an air-cooled condenser for heat rejection. While this reduces the water consumption of the plant, it results in performance penalties in the overall plant between 5-10% [1]. Passive cooling methods can be used to alleviate the performance penalties. While passive cooling methods have been studied and used on a small scale, this model explores the possibilities of applying these methods to large-scale solar thermal power plants. Based on the model developed, it was found that underground-cooling techniques can improve the performance of the overall dry cooled solar thermal power plant by up to 3% at peak dry bulb temperatures. This study finds that there is a possibility to apply these passive cooling techniques on a large scale to yield positive results. INTRODUCTION: Commercial solar thermal power plants rely predominantly on the Rankine cycle for operation. One of the main concerns in the operation of these plants is the large amount of water consumption in locations where water is generally scarce, desert settings. The main water consumption goes into providing cooling to condense steam exiting the turbine and make up water for the steam cycle. Methods to alleviate the water consumption by means of dry cooling in the condensation process have been propose

Enhanced J-protein interaction and compromised protein stability of mtHsp70 variants lead to mitochondrial dysfunction in Parkinsons disease

Parkinsons disease (PD) is the second most prevalent progressive neurological disorder commonly associated with impaired mitochondrial function in dopaminergic neurons. Although familial PD is multifactorial in nature, a recent genetic screen involving PD patients identified two mitochondrial Hsp70 variants (P509S and R126W) that are suggested in PD pathogenesis. However, molecular mechanisms underlying how mtHsp70 PD variants are centrally involved in PD progression is totally elusive. In this article, we provide mechanistic insights into the mitochondrial dysfunction associated with human mtHsp70 PD variants. Biochemically, the R126W variant showed severely compromised protein stability and was found highly susceptible to aggregation at physiological conditions. Strikingly, on the other hand, the P509S variant exhibits significantly enhanced interaction with J-protein cochaperones involved in folding and import machinery, thus altering the overall regulation of chaperone-mediated folding cycle and protein homeostasis. To assess the impact of mtHsp70 PD mutations at the cellular level, we developed yeast as a model system by making analogous mutations in Ssc1 ortholog. Interestingly, PD mutations in yeast (R103W and P486S) exhibit multiple in vivo phenotypes, which are associated with omitochondrial dysfunction', including compromised growth, impairment in protein translocation, reduced functional mitochondrial mass, mitochondrial DNA loss, respiratory incompetency and increased susceptibility to oxidative stress. In addition to that, R103W protein is prone to aggregate in vivo due to reduced stability, whereas P486S showed enhanced interaction with J-proteins, thus remarkably recapitulating the cellular defects that are observed in human PD variants. Taken together, our findings provide evidence in favor of direct involvement of mtHsp70 as a susceptibility factor in PD

Role of the loop L-4,L-5 in allosteric regulation in mtHsp70s: in vivo significance of domain communication and its implications in protein translocation

Mitochondrial Hsp70 (mtHsp70) is essential for a vast repertoire of functions, including protein import, and requires effective interdomain communication for efficient partner-protein interactions. However, the in vivo functional significance of allosteric regulation in eukaryotes is poorly defined. Using integrated biochemical and yeast genetic approaches, we provide compelling evidence that a conserved substrate-binding domain (SBD) loop, L-4,L-5, plays a critical role in allosteric communication governing mtHsp70 chaperone functions across species. In yeast, a temperature-sensitive L-4,L-5 mutation (E467A) disrupts bidirectional domain communication, leading to compromised protein import and mitochondrial function. Loop L-4,L-5 functions synergistically with the linker in modulating the allosteric interface and conformational transitions between SBD and the nucleotide-binding domain (NBD), thus regulating interdomain communication. Second-site intragenic suppressors of E467A isolated within the SBD suppress domain communication defects by conformationally altering the allosteric interface, thereby restoring import and growth phenotypes. Strikingly, the suppressor mutations highlight that restoration of communication from NBD to SBD alone is the minimum essential requirement for effective in vivo function when primed at higher basal ATPase activity, mimicking the J-protein-bound state. Together these findings provide the first mechanistic insights into critical regions within the SBD of mtHsp70s regulating interdomain communication, thus highlighting its importance in protein translocation and mitochondrial biogenesis

Cushing's Disease: results of treatment and factors affecting outcome

Objective: To analyze the therapeutic results of intervention and the factors affecting the outcome of patients with Cushing’s Disease (CD) cared for at the All Indian Institute of Medical Science (AIIMS), New Delhi. Design: Patients with Cushing’s Disease treated at a teritiary care centre from January 2000 to December 2009 were prospectively studied. Results: Ninety-seven patients received treatment for CD during this period. Mean duration of follow-up was 3.4 &#177; 2.2 (mean&#177;SD) years. Eighty-one patients (83.5%) underwent Transsphenoidal Surgery (TSS) as the primary treatment modality. Fifty-four patients (66.7%) went into remission after initial TSS; ten (18.5%) of them relapsed after a mean follow-up period of 2.9&#177;2.1 (mean&#177;SD) years. Histopathologic examination of resected tissue showed corticotroph adenoma in 48 of the 54 (88.9%) who went into remission and 17 of the 27 (63.0%) who did not go into remission after the initial TSS. Sixteen patients with severe hypercortisolism underwent Bilateral Adrenalectomy (BA) as a life-saving measure which was followed by pituitary surgery 6 to 12 months later. Five patients including one with a large macroadenoma required three or more procedures to achieve eucortisolism. Conclusion: Fifty-four out of 81 (66.7%) of our patients with CD had remission following initial TSS, ten of whom relapsed later on. Sixteen patients unerwent BA as a life-saving procedure. Factors affecting outcome were, age, gender, low dose dexamethasone suppression test cortisol value and histologic confirmation of corticotroph adenom