Fear of COVID-19 Scale for Hospital Staff in Regional Hospitals in Mexico: a Brief Report

International Journal of Mental Health and Addiction - The presence of COVID-19 has had psychological consequences among health personnel; these include fear, anxiety, and depression. In the...     

Antioxidant effects of taurine, vitamin C, and vitamin E on oxidative damage in hippocampus caused by the administration of 3-nitropropionic acid in rats

The administration of 3-nitropropionic acid increases reactive oxygen species (ROS). Antioxidant defense mechanisms buffer these ROS converting them into non-damaging compounds. Taurine and vitamins C and E are antioxidants that play a role in the defense against cellular damage. This study examines the antioxidant effect of taurine, vitamin C, and vitamin E on acute hippocampal damage caused by 3-NP. Animals treated with 3-NP increased lipid peroxidation levels and astrocytic damage in the hippocampus. Administration of taurine, vitamin C, and vitamin E partially protected from oxidative damage, indicate that while all substances had antioxidant effects, only taurine showed morphological protection in surviving cells.     

Local auxin biosynthesis regulation by PLETHORA transcription factors controls phyllotaxis in Arabidopsis

Lateral organ distribution at the shoot apical meristem defines specific and robust phyllotaxis patterns that have intrigued biologists and mathematicians for centuries. In silico studies have revealed that this self-organizing process can be recapitulated by modeling the polar transport of the phytohormone auxin. Phyllotactic patterns change between species and developmental stages, but the processes behind these variations have remained unknown. Here we use regional complementation experiments to reveal that phyllotactic switches in Arabidopsis shoots can be mediated by PLETHORA-dependent control of local auxin biosynthesis.     

Inhibition of human P450 enzymes by natural extracts used in traditional medicine

Different medicinal plants are widely used in Cuba and Mexico to treat several disorders. This paper reports in vitro inhibitory effects on the P450 system of herbal products commonly used by people in Cuba and Mexico in traditional medicine for decades. Experiments were conducted in human liver microsomes. The catalytic activities of CYP1A1/2, 2D6, and 3A4 were measured using specific probe substrates. The Heliopsis longipes extract exhibited a concentration-dependent inhibition of the three enzymes, and similar effects were produced by affinin (an alkamide isolated from the H. longipes extract) and two catalytically reduced alkamides. Mangifera indica L. and Thalassia testudinum extracts, two natural polyphenol-rich extracts, diminished CYP1A1/2 and 3A4 activities, but not the CYP2D6 activity. These results suggest that these herbs inhibit the major human P450 enzymes involved in drug metabolism and could induce potential herbal-drug interactions.     

The paradox of natural products as pharmaceuticals. Experimental evidences of a mango stem bark extract.

Recent findings regarding basic, pre-clinical and clinical studies on a mango stem bark extract (MSBE) developed in Cuba (Vimang) on an industrial scale are summarized. Ethnomedical studies, extract reproducibility, biological effects and clinical evaluations in terms of patient quality of life are described as experimental evidences to support the statement that natural products, even being a mixture of compounds, could be as effective as "monoceuticals" for medical uses. Discussion about the use of "monoceuticals" versus "natureceuticals" in health care and medicine is based on effectiveness and availability, taking Vimang as an example of a natural product with supported scientific evidence to be used as antioxidant, analgesic, anti-inflammatory and immunomodulator.     

Oxidative damage in substantia nigra and striatum of rats chronically exposed to ozone

The purpose of this work was to study if chronic low-dose ozone exposure could per se induce oxidative damage to neurons of striatum and substantia nigra. Thirty male Wistar rats were divided into three groups--Group 1: exposed to an air stream free of ozone; Group 2: exposed for 15 days to ozone; Group 3: exposed for 30 days to ozone. Ozone exposure was carried out daily for 4 h at a 0.25 ppm dose. Each group was then tested for (1) motor activity, (2) quantification of lipid peroxidation levels, (3) Klüver-Barrera staining, and (4) immunohistochemistry for tyrosine hydroxylase (TH), dopamine and adenosine 3',5'-monophosphate-regulated phosphoprotein of 32 kD (DARPP-32), inducible nitric oxide synthase (iNOS), and superoxide dismutase (SOD), to study neuronal alterations in striatum and substantia nigra. Results indicate that ozone exposure causes a significant decrease in motor activity. Ozone produced lipid peroxidation, morphological alterations, loss of fibers and cell death of the dopaminergic neurons. The DARPP-32, iNOS and SOD expression increased with repetitive ozone exposure. These alterations suggest that ozone causes oxidative stress which induces oxidative damage to substantia nigra and striatum of the rat.     

MHC class I molecules exploit the low G+C content of pathogen genomes for enhanced presentation

Distinguishing self from nonself and pathogenic from nonpathogenic is a fundamental challenge to the immune system but whether adaptive immune systems use pathogen-specific signatures to achieve this is largely unknown. By investigating the presentation of large sets of viruses and bacteria on MHC class I molecules, we analyze whether MHC-I molecules have a preference for pathogen-derived peptides. The fraction of potential MHC-I binders in different organisms can vary up to eight-fold. We find that this variation can be largely explained by G+C content differences of the organisms, which are reflected in amino acid frequencies. A significant majority of HLA-A, but not HLA-B, molecules has a preference for peptides derived from organisms with a low G+C content. Interestingly, a low G+C content seems to be a universal signature for pathogenicity. Finally, we find the same preferences in chimpanzee and rhesus macaque MHC-I molecules. These results demonstrate that despite the fast evolution of MHC-I alleles and their extreme polymorphism and diversity in peptide-binding preferences, MHC-I molecules can acquire a preference to exploit pathogen-specific signatures.     

L-alanyl-L-glutamine-supplemented parenteral nutrition improves infectious morbidity in secondary peritonitis

BACKGROUND & AIMS: A growing number of randomized clinical trials suggest that glutamine (Gln) supplementation may be beneficial in a selected group of patients and conditions. However, the effects of Gln-enriched total parenteral nutrition (TPN) on recovery from acute intra-abdominal infection have not been thoroughly investigated. Therefore, the aim of this study was to investigate whether the provision of Gln-enriched TPN after surgical and medical treatment of secondary peritonitis improves infectious morbidity.METHODS: Thirty-three patients with secondary peritonitis were randomly assigned to receive either standard (n=16) TPN or L-alanyl-L-glutamine-supplemented (n=17) TPN, after medical and surgical treatment of the infectious focus. The two TPN formulae were isonitrogenous and isocaloric, which commenced the morning after surgery and ran continuously for 10 consecutive days. The control group received standard TPN, while the treatment group was given L-alanyl-L-glutamine, 0.40 g/kg/d (Dipeptiven, Fresenius Kabi, Bad Homburg, Germany). Infectious morbidity, nitrogen balance, leukocytes, lymphocytes, subpopulations CD(4) and CD(8), Immunoglobulin A (IgA), total proteins, albumin, hospital and intensive care unit (ICU) stays, and mortality were evaluated. Statistical analysis included one-way ANOVA, the unpaired Student's t-test, the Mann-Whitney U-test, chi(2) test, or Fisher's exact test. RESULTS: Patients in both groups were comparable prior to the operation. Nitrogen balance and the levels of albumin and IgA were significantly better than those in the control group. Also, a significant reduction in the infectious morbidity was found in the Gln-treated group. Lymphocyte counts as well as subpopulations CD(4) and CD(8), and proteins showed a propensity to improvement and a tendency to reduced rates of mortality were observed when comparing the groups. Hospital and ICU stays were similar. CONCLUSION: L-alanyl-L-glutamine-supplemented TPN improved the infectious morbidity of patients with secondary peritonitis. Gln supplementation to parenteral nutrition may be an alternative for enhancing host defenses and improving infectious morbidity.     

Anti-allergic properties of Mangifera indica L. extract (Vimang) and contribution of its glucosylxanthone mangiferin

Vimang is the brand name of formulations containing an extract of Mangifera indica L., ethnopharmacologically used in Cuba for the treatment of some immunopathological disorders, including bronchial asthma, atopic dermatitis and other allergic diseases. However, the effects of Vimang on allergic response have not been reported until now. In this study, the effects of Vimang and mangiferin, a C-glucosylxanthone isolated from the extract, on different parameters of allergic response are reported. Vimang and mangiferin showed a significant dose-dependent inhibition of IgE production in mice and anaphylaxis reaction in rats, histamine-induced vascular permeability and the histamine release induced by compound 48/80 from rat mast cells, and of lymphocyte proliferative response as evidence of the reduction of the amount of B and T lymphocytes able to contribute to allergic response. In these experiments, ketotifen, promethazine and disodium cromoglicate were used as reference drugs. Furthermore, we demonstrated that Vimang had an effect on an in-vivo model of inflammatory allergy mediated by mast cells. These results constitute the first report of the anti-allergic properties of Vimang on allergic models, as well as suggesting that this natural extract could be successfully used in the treatment of allergic disorders. Mangiferin, the major compound of Vimang, contributes to the anti-allergic effects of the extract.     

Platelet count/spleen diameter ratio to predict esophageal varices in Mexican patients with hepatic cirrhosis

AIM:To validate whether the platelet count/spleen size ratio can be used to predict the presence of esophageal varices in Mexican patients with hepatic cirrhosis.METHODS:This was an analytical cross-sectional study to validate the diagnostic test for hepatic cirrhosis and was performed between February 2010 and December 2011.Patients with a diagnosis of hepatic cirrhosis were included and stratified using their ChildPugh score.Biochemical parameters were evaluated,and ultrasound was used to measure the longest diameter of the spleen.The platelet count/spleen diameter ratio was calculated and analyzed to determine whether it can predict the presence of esophageal varices.Upper gastrointestinal endoscopy was used as the gold standard.Sensitivity and specificity,positive and negative predictive values,and positive and negative likelihood ratios were determined,with the cutoff points determined by receiver-operating characteristic curves.RESULTS:A total of 91 patients were included.The mean age was 53.75±12 years;50(54.9%)were men,and 41(45.0%)women.The etiology of cirrhosis included alcohol in 48(52.7%),virally induced in24(26.3%),alcoholism plus hepatitis C virus in three(3.2%),cryptogenic in nine(9.8%),and primary biliary cirrhosis in seven(7.6%).Esophageal varices were present in 73(80.2%)patients.Child-Pugh classification,17(18.6%)patients were classified as class A,37(40.6%)as class B,and 37(40.6%)as class C.The platelet count/spleen diameter ratio to detect esophageal varices independent of the grade showed using a cutoff value of≤884.3,had 84%sensitivity,70%specificity,and positive and negative predictive values of 94%and 40%,respectively.CONCLUSION:Our results suggest that the platelet count/spleen diameter ratio may be a useful tool for detecting esophageal varices in patients with hepatic cirrhosis.