270 research outputs found
Expression of proto-oncogenes and muscle specific genes during cardiac hypertrophy and development in rats and humans
A regulatory interdependence of expression of proto-oncogenes and muscle specific genes observed in smooth muscle was examined in cardiac muscle during normal development and hypertrophy both in rats and humans. During normal development in rats, myosin light chain 2 expression is very low at prenatal stages, while c-fos expression starts from the early stages of embryonic development. In aorta constricted rats c-fos induction occurs within 30 min whereas myosin light chain 2 expression is sufficiently high only after 3 or 4 days of post operative period. In the case of humans, the expression of myosin light chain 2 as well as c-fos occurs at high levels during embryonic development. Similar results were obtained with tissue samples obtained from patients with cardiac abnormalities. Induction of the c-fos gene in cultured myocytes by 12-O-tetradeeanoylphorbol 13-acetate has no influence on the expression of myosin light chain 2. These studies were extended with studies on c-myc and Î’-myosin heavy chain gene expression which revealed a similar pattern of expression as that of c-fos and myosin light chain 2. These results have indicated that the expression of proto-oncogenes in cardiac muscle may be independently regulated from the expression of muscle specific genes
Efficient methods for enol phosphate synthesis using carbon-centred magnesium bases
Efficient conversion of ketones into kinetic enol phosphates under mild and accessible conditions has been realised using the developed methods with di-tert-butylmagnesium and bismesitylmagnesium. Optimisation of the quench protocol resulted in high yields of enol phosphates from a range of cyclohexanones and aryl methyl ketones, with tolerance of a range of additional functional units
Altered Circulating Levels of Matrix Metalloproteinases and Inhibitors Associated with Elevated Type 2 Cytokines in Lymphatic Filarial Disease
Lymphatic filariasis afflicts over 120 million people worldwide. While the infection is mostly clinically asymptomatic, approximately 40 million people suffer from overt, morbid clinical pathology characterized by swelling of the scrotal area and lower limbs (hydrocele and lymphedema). Host immunologic factors that influence the pathogenesis of disease in these individuals are not completely understood. Matrix metalloproteinases are a family of circulating and tissue proteins that influence the development of tissue fibrosis. They are regulated by another family of proteins called tissue inhibitors of metalloproteinases. The interplay between these proteins governs tissue fibrosis in a variety of conditions. In addition, certain cytokines are known to promote pro-fibrotic events. We have attempted to elucidate the role of the above-mentioned factors in disease pathogenesis by comparing the plasma levels of the various markers in four groups of individuals: chronic pathology individuals with or without active filarial infection; asymptomatic, filaria-infected individuals; and uninfected, endemic normal individuals. We show that altered ratios of the metalloproteinases and their inhibitors—as well as elevated levels of pro-fibrotic cytokines—characterize filarial infection-induced lymphatic pathology
Predicting electronic structures at any length scale with machine learning
The properties of electrons in matter are of fundamental importance. They
give rise to virtually all molecular and material properties and determine the
physics at play in objects ranging from semiconductor devices to the interior
of giant gas planets. Modeling and simulation of such diverse applications rely
primarily on density functional theory (DFT), which has become the principal
method for predicting the electronic structure of matter. While DFT
calculations have proven to be very useful to the point of being recognized
with a Nobel prize in 1998, their computational scaling limits them to small
systems. We have developed a machine learning framework for predicting the
electronic structure on any length scale. It shows up to three orders of
magnitude speedup on systems where DFT is tractable and, more importantly,
enables predictions on scales where DFT calculations are infeasible. Our work
demonstrates how machine learning circumvents a long-standing computational
bottleneck and advances science to frontiers intractable with any current
solutions. This unprecedented modeling capability opens up an inexhaustible
range of applications in astrophysics, novel materials discovery, and energy
solutions for a sustainable future
Helminth-induced arginase-1 exacerbates lung inflammation and disease severity in tuberculosis
Parasitic helminth worms, such as Schistosoma mansoni, are endemic in regions with a high prevalence of tuberculosis (TB) among the population. Human studies suggest that helminth coinfections contribute to increased TB susceptibility and increased rates of TB reactivation. Prevailing models suggest that T helper type 2 (Th2) responses induced by helminth infection impair Th1 immune responses and thereby limit Mycobacterium tuberculosis (Mtb) control. Using a pulmonary mouse model of Mtb infection, we demonstrated that S. mansoni coinfection or immunization with S. mansoni egg antigens can reversibly impair Mtb-specific T cell responses without affecting macrophage-mediated Mtb control. Instead, S. mansoni infection resulted in accumulation of high arginase-1–expressing macrophages in the lung, which formed type 2 granulomas and exacerbated inflammation in Mtb-infected mice. Treatment of coinfected animals with an antihelminthic improved Mtb-specific Th1 responses and reduced disease severity. In a genetically diverse mouse population infected with Mtb, enhanced arginase-1 activity was associated with increased lung inflammation. Moreover, in patients with pulmonary TB, lung damage correlated with increased serum activity of arginase-1, which was elevated in TB patients coinfected with helminths. Together, our data indicate that helminth coinfection induces arginase-1–expressing type 2 granulomas, thereby increasing inflammation and TB disease severity. These results also provide insight into the mechanisms by which helminth coinfections drive increased susceptibility, disease progression, and severity in TB
Transcriptional and immunohistological assessment of immune infiltration in pancreatic cancer.
Pancreatic adenocarcinoma is characterized by a complex tumor environment with a wide diversity of infiltrating stromal and immune cell types that impact the tumor response to conventional treatments. However, even in this poorly responsive tumor the extent of T cell infiltration as determined by quantitative immunohistology is a candidate prognostic factor for patient outcome. As such, even more comprehensive immunophenotyping of the tumor environment, such as immune cell type deconvolution via inference models based on gene expression profiling, holds significant promise. We hypothesized that RNA-Seq can provide a comprehensive alternative to quantitative immunohistology for immunophenotyping pancreatic cancer. We performed RNA-Seq on a prospective cohort of pancreatic tumor specimens and compared multiple approaches for gene expression-based immunophenotyping analysis compared to quantitative immunohistology. Our analyses demonstrated that while gene expression analyses provide additional information on the complexity of the tumor immune environment, they are limited in sensitivity by the low overall immune infiltrate in pancreatic cancer. As an alternative approach, we identified a set of genes that were enriched in highly T cell infiltrated pancreatic tumors, and demonstrate that these can identify patients with improved outcome in a reference population. These data demonstrate that the poor immune infiltrate in pancreatic cancer can present problems for analyses that use gene expression-based tools; however, there remains enormous potential in using these approaches to understand the relationships between diverse patterns of infiltrating cells and their impact on patient treatment outcomes
Unilateral hemothorax in a 46 year old South Indian male due to a giant arteriovenous hemodialysis fistula: a case report
In a patient undergoing regular hemodialysis through an arteriovenous fistula access, pleural effusion is a known long term complication. However, a unilateral hemothorax is relatively uncommon. Here we report a 46 year old male, end-stage renal disease patient, on maintenance hemodialysis, who presented with a giant brachiocephalic AV fistula in his left arm and progressive breathlessness. Radiological imaging revealed a left sided pleural effusion. Ultrasound guided aspiration revealed a hemorrhagic pleural fluid. A Doppler study of the fistula revealed a high velocity blood flow through the fistula, thereby establishing the cause of the unilateral hemothorax. Ligation of the fistula resulted in complete resolution of the hemothorax. The other possible causes for hemothorax in a dialysis patient are also discussed in this case report
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