DETECTION OF VIBRIO ALGINOLYTICUS AND VIBRIO PARAHAEMOLYTICUS IN SHELLFISH SAMPLES USING COLLAGENASE-TARGETED MULTIPLEX-PCR

The increase of Vibrio infections especially associated with the consumption of contaminated seafood and fish underlines the necessity of an efficient monitoring system for Vibrio spp. supported by appropriate detection tools both in food products and in clinical samples. The aim of this study was the evaluation of the reliability of the collagenase‐targeted multiplex‐polymerase chain reaction (m‐PCR) for the detection of Vibrio alginolyticus, Vibrio cholerae and Vibrio parahaemolyticus in shellfish samples enriched in alkaline peptone water (APW). The coupling of a pre‐enrichment phase of the samples with the specificity of the PCR‐based assay was applied successfully to the detection of V. alginolyticus and V. parahaemolyticus, demonstrating that collagenase‐target m‐PCR may be used as a valid molecular target to discriminate the three Vibrio species.     

MUSCLE AND ROE LIPID COMPOSITION IN DIPLOID AND TRIPLOID SCALLOPS

The use of triploid bivalves is now common in the market. We tested if there was a difference in lipid and long-chain highly unsaturated fatty acid (HUFA) accumulation in the muscle of diploid and triploid scallops ( Argopecten ventricosus ) during maturation, as triploids do not reproduce and lipids are not transferred to the gonad, and thus, could be accumulated in the meat (adductor muscle). Differences in triacylglycerols, phospholipids, esterified and free sterols, as well as HUFA in the reserves of gonads were found between diploid and triploid scallops. In contrast, no differences were found in the muscle for any of the lipid classes or fatty acid content in relation to ploidy, although they varied in relation to the sampling month.

PRACTICAL APPLICATIONS

The results obtained indicate that for human consumption purposes, the quality of the meat and roe of scallops follows a temporal pattern of lipid accumulation, with higher levels of total sterols in summer, but a higher proportion of arachidonic acid in winter and lower docosahexaenoic acid in autumn, and that the muscle lipid composition is not affected by the triploid condition.     

ABSENCE OF PROTEOLYSIS IN PURIFIED MYOFIBRILS OF POSTSPAWNED HAKE (MERLUCCIUS HUBBSI MARINI) DURING IN VITRO STORAGE AT 37C

The biochemical behavior of myofibrils from postspawned hake during in vitro storage at 37C was investigated. SDS‐PAGE, densitometric analysis of the band areas corresponding to the major myofibrillar proteins, and TCA soluble peptides determination showed no evidence of proteolysis in myofibrils after 44 h of incubation either in presence or in absence of a cocktail of protease inhibitors (1 mMPMSF+1mMiodoacetic acid + 1mM of EDTA). The absence of proteolysis in stored postspawned hake myofibrils contrasts with the autolysis in those from prespawned fish previously reported, indicating an influence of the reproductive cycle on the proteolytic activity closely associated to myofibrils.     

Effect of Addition of Chloride Salts on Rancidity of Ground Pork Inoculated with a Moraxella or a Lactobacillus Species

Two experiments were conducted to determine rancidity development in raw-refrigerated ground pork treated with different types and levels of chloride salts. In the first experiment, raw ground pork was inoculated with either a Moraxella or a Lactobacillus species. In the second experiment, samples were not inoculated. In both experiments, samples were treated with either NaCl, KCl, or MgCl₂ at ionic strength of either 0.73 or 0.37 and stored at 5°C. Regardless of inoculation, in both experiments addition of any chloride salt increased (P < 0.05) TBA values over those values for controls (no added salt). Addition of NaCl resulted in the highest (P < 0.05) TBA values among inoculated samples, but these differences were not apparent for noninoculated samples.     

Morphological study of the spermatogenesis in the teleost <i>Piaractus mesopotamicus</i>

The spermatogenesis of Piaractus mesopotamicus was investigated under light and transmission electron microscopy. The specimens were captured from their natural environment (Rio Miranda and Rio Aquidauana, Pantanal Matogrossense, Brazil) during April and September. The results were compared with the spermatogenic data of specimens under captivity condition. In both conditions, P. mesopotamicus presented the typical spermatogenesis pattern of the teleost fishes, showing no significative differences. The spermatozoon was classified as type I, which has a globular head without acrosome, a short middle piece and a long tail constituted only by the flagellum. This type of spermatozoon is considered the basic type in fishes.     

DNA mismatch repair gene methylation in gastric cancer in individuals from northern Brazil

Gastric cancer is one of the most common malignancies. DNA methylation is implicated in DNA mismatch repair genes deficiency. In the present study, we evaluated the methylation status of MLH1, MSH2, MSH6 and PMS2 in 20 diffuse- and 26 intestinal-type gastric cancer samples and 20 normal gastric mucosal of gastric cancer patients from Northern Brazil. We found that none of the nonneoplastic samples showed methylation of any gene promoter and 50% of gastric cancer samples showed at least one methylated gene promoter. Methylation frequencies of MLH1, MSH2, MSH6 and PMS2 promoter were 21.74%, 17.39%, 0% and 28.26% respectively in gastric cancer samples. MLH1 and PMS2 methylation were associated with neoplastic samples compared to nonneoplastic ones. PMS2 methylation was associated with diffuse- and intestinal-type cancer compared with normal controls. Intestinal-type cancer showed significant association with MLH1 methylation. Diffuse-type cancer was significantly associated with MSH2 methylation. Our findings show differential gene methylation in tumoral tissue, which allows us to conclude that methylation is associated with gastric carcinogenesis. Methylation of mismatch repair genes was associated with gastric carcinogenesis and may be a helpful tool for diagnosis, prognosis and therapies. However, MSH6 does not seem to be regulated by methylation in our samples.     

SARS-CoV-2 induced myocarditis: Current knowledge about its molecular and pathophysiological mechanisms

The existence of an inflammatory process in the heart muscle, related to a progressive worsening of myocardial function, different etiopathogenetic mechanisms concur and often overlap, thus making the diagnosis and the therapeutic approach complex. As the COVID-19 pandemic progresses, the effects of the disease on the organ systems and in particular on the cardiovascular system are becoming more and more profound. Cardiac involvement is a well-known event with a high percentage of findings in the heart’s magnetic field, even in asymptomatic areas. There are numerous uncertainties regarding their evolution, in the long and short term, due not only to a difficult to determine the varied clinical expression and the rarely performed intramyocardial biopsy which additionally presents diagnostic problems but also in part to different clinical prognosis. Today, the new SARS-CoV-2 virus that uses the angiotensin converting enzyme 2 (ACE2) which is present at high levels in myocardial cells as its entrance it can create even severe heart injury. The pathophysiology in all of these cases can involve multiple immune and non-immune mechanisms within organs and vessels and can be occur in the clinical phases. Possible mechanisms of direct and indirect myocardial infarction in patients with COVID-19 include additional lesion and oxygen-rich and generalized inflammation response with myocardial immune hyperactivity (myocarditis). Therefore, these can occur through the excessive release of cytokines, the presence of thrombocytopenia, endocrine damage, heart failure, arrhythmias and more. Patients can show average signs of myocardial damage, and some develop spontaneous cardiac complications, such as heart failure, arrhythmias and, rarely, rare cardiogenic disorders. Pathophysiology in all of these may involve multiple mechanisms within the cytokine cephalic membrane, endocrine damage and thrombogenicity. The diagnosis of this myocardial injuri is mainly based on the myocardial enzyme troponin. This viewpoint paper explains today’s knowledge on viral myocarditis, in particular that from SARS-CoV-2 infection, if there is a connection with other possible biomolecular pathogenetic factors that can influence its natural course. In fact, it is for this reason that the pathogenetic mechanisms are analyzed and described. At the same time, its possible interaction with other parameters that are documented risk factors for cardiovascular disease was examined. Although these biomolecular findings were mainly related to necrotic parts of the myocardium, it is important to recognize that myocardial damage early for a better approach and prognosis.