Alteration of prostaglandin metabolism in alcoholic liver disease: its association with platelet dysfunction after chronic alcohol ingestion

Recently, hepatic microcirculation has been focused on as an important pathogenic factor in progression of alcoholic liver disease (ALD). Therefore, blood levels of several prostaglandins, which are associated with organ microcirculation, were determined in various liver diseases, including ALD. Blood thromboxane B2 (TXB2) level was significantly increased in ALD, when compared to other types of liver diseases, whereas both 6-keto prostaglandin F1 alpha (6-keto PGF1 alpha) and prostaglandin E were not changed. These consequences resulted in the imbalance of 6-keto PGF1 alpha to TXB2, which might promote platelet aggregation and blood vessel contraction. Indeed, the increase of beta-thromboglobulin and platelet factor 4 in blood was observed in ALD. Furthermore, in ALD, the rate of arachidonate-induced platelet aggregation was prominently enhanced, and malondialdehyde production in platelet, which was well correlated with blood TXB2 levels, significantly increased. Thus, the present study may indicate that, in ALD, hyper-aggregability of platelet is produced, because of the derangement of prostaglandin metabolism and platelet dysfunction.     

Dual Effect of Organogermanium Compound THGP on RIG-I-Mediated Viral Sensing and Viral Replication during Influenza a Virus Infection

The interaction of viral nucleic acid with protein factors is a crucial process for initiating viral polymerase-mediated viral genome replication while activating pattern recognition receptor (PRR)-mediated innate immune responses. It has previously been reported that a hydrolysate of Ge-132, 3-(trihydroxygermyl) propanoic acid (THGP), shows a modulatory effect on microbial infections, inflammation, and immune responses. However, the detailed mechanism by which THGP can modify these processes during viral infections remained unknown. Here, we show that THGP can specifically downregulate type I interferon (IFN) production in response to stimulation with a cytosolic RNA sensor RIG-I ligand 5′-triphosphate RNA (3pRNA) but not double-stranded RNA, DNA, or lipopolysaccharide. Consistently, treatment with THGP resulted in the dose-dependent suppression of type I IFN induction upon infections with influenza virus (IAV) and vesicular stomatitis virus, which are known to be mainly sensed by RIG-I. Mechanistically, THGP directly binds to the 5′-triphosphate moiety of viral RNA and competes with RIG-I-mediated recognition. Furthermore, we found that THGP can directly counteract the replication of IAV but not EMCV (encephalitismyocarditis virus), by inhibiting the interaction of viral polymerase with RNA genome. Finally, IAV RNA levels were significantly reduced in the lung tissues of THGP-treated mice when compared with untreated mice. These results suggest a possible therapeutic implication of THGP and show direct antiviral action, together with the suppressive activity of innate inflammation.     

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Pandemic: Is Sequela the Bigger Threat?

How to cite this article: Rai N, Baidya DK. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Pandemic: Is Sequela the Bigger Threat? Indian J Crit Care Med 2021;25(2):245–246.     

Quick detection of brain tumors and edemas: A bounding box method using symmetry

A significant medical informatics task is indexing patient databases according to size, location, and other characteristics of brain tumors and edemas, possibly based on magnetic resonance (MR) imagery. This requires segmenting tumors and edemas within images from different MR modalities. To date, automated brain tumor or edema segmentation from MR modalities remains a challenging, computationally intensive task. In this paper, we propose a novel automated, fast, and approximate segmentation technique. The input is a patient study consisting of a set of MR slices, and its output is a subset of the slices that include axis-parallel boxes that circumscribe the tumors. Our approach is based on an unsupervised change detection method that searches for the most dissimilar region (axis-parallel bounding boxes) between the left and the right halves of a brain in an axial view MR slice. This change detection process uses a novel score function based on Bhattacharya coefficient computed with gray level intensity histograms. We prove that this score function admits a very fast (linear in image height and width) search to locate the bounding box. The average dice coefficients for localizing brain tumors and edemas, over ten patient studies, are 0.57 and 0.52, respectively, which significantly exceeds the scores for two other competitive region-based bounding box techniques.     

Intestinal bleeding from arteriovenous malformations of the small bowel in a patient with Cowden syndrome: report of a case

This report presents the case of a patient with Cowden syndrome who had arteriovenous malformations (AVMs) at the jejunum and the ileum and experienced intestinal bleeding. A 54-year-old Japanese male presented with general fatigue and melena. Endoscopic examinations showed gastrointestinal polyposis from the esophagus to the rectum. However, the site of bleeding was not identified. There were some papules on his face and neck. He also had macrocephaly and had multiple papillomas along the gum-line. These findings indicated a clinical diagnosis of Cowden syndrome. Enhanced computed tomography (CT) and angiography analyses indicated the presence of AVMs at the jejunum and the ileum. He was treated with partial resection of the jejunum and ileum including these two AVMs. This was a rare case of two AVMs involving the small bowel in a patient with Cowden syndrome. Enhanced CT was very useful and convenient for the detection of gastrointestinal AVMs in this case.