Functional Histology and Ultrastructure of the Digestive Tract in Two Species of Chitons (Mollusca, Polyplacophora)

. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.To continue the investigation on the digestive system of polyplacophoran molluscs, a histological and ultrastructural study of the oesophagus, stomach and intestine of Chaetopleura angulata and Acanthochitona fascicularis was carried out. Stomach content examination revealed an omnivorous diet. In both species the epithelium of the whole digestive tract consisted mostly of elongated absorptive cells with an apical border of microvilli. Cilia were also frequently present. Mitochondria and electron-dense lysosomes were the prominent organelles in the region above the nucleus. The basal region was characterised by an association of mitochondria, peroxisomes and lipid droplets. In general, glycogen deposits were also abundant in absorptive cells. The ultrastructural features indicate that the absorptive cells of the digestive tract epithelium are involved in endocytosis, intracellular digestion and storage of reserves. Histochemical techniques showed that the secretory cells of the digestive tract contained proteins and polysaccharides in their secretory vesicles. The secretory cells with vesicles of low electron density were classified as mucous cells, and the ones with electron-dense vesicles were designated basophilic cells due to their staining by basic dyes in light microscopy. Additionally, basal cells that seem to correspond to enteroendocrine cells containing oval electron-dense vesicles were found along the digestive tract epithelium of both species. The thin outer layer of the digestive tract wall consisted of muscle cells and nerves embedded in connective tissue.publishersversionpublishe

Inactivation of Geobacillus stearothermophilus spores by alkaline hydrolysis applied to medical waste treatment

Although alkaline hydrolysis treatment emerges as an alternative disinfection/sterilization method for medical waste, information on its effects on the inactivation of biological indicators is scarce. The effects of alkaline treatment on the resistance of Geobacillus stearothermophilus spores were investigated and the influence of temperature (80 degrees C, 100 degrees C and 110 degrees C) and NaOH concentration was evaluated. In addition, spore inactivation in the presence of animal tissues and discarded medical components, used as surrogate of medical waste, was also assessed. The effectiveness of the alkaline treatment was carried out by determination of survival curves and D-values. No significant differences were seen in D-values obtained at 80 degrees C and 100 degrees C for NaOH concentrations of 0.5 M and 0.75 M. The D-values obtained at 110 degrees C (2.3-0.5 min) were approximately 3 times lower than those at 100 degrees C (8.8-1.6 min). Independent of the presence of animal tissues and discarded medical components, 6 log10 reduction times varied between 66 and 5 min at 100 degrees C-0.1 M NaOH and 110 degrees C-1 M NaOH, respectively. The alkaline treatment may be used in future as a disinfection or sterilization alternative method for contaminated waste

A glycolytic phenotype is associated with prostate cancer progression and aggressiveness: a role for monocarboxylate transporters as metabolic targets for therapy.

Metabolic adaptation is considered an emerging hallmark of cancer, whereby cancer cells exhibit high rates of glucose consumption with consequent lactate production. To ensure rapid efflux of lactate, most cancer cells express high levels of monocarboxylate transporters (MCTs), which therefore may constitute suitable therapeutic targets. The impact of MCT inhibition, along with the clinical impact of altered cellular metabolism during prostate cancer (PCa) initiation and progression, has not been described. Using a large cohort of human prostate tissues of different grades, in silico data, in vitro and ex vivo studies, we demonstrate the metabolic heterogeneity of PCa and its clinical relevance. We show an increased glycolytic phenotype in advanced stages of PCa and its correlation with poor prognosis. Finally, we present evidence supporting MCTs as suitable targets in PCa, affecting not only cancer cell proliferation and survival but also the expression of a number of hypoxia-inducible factor target genes associated with poor prognosis. Herein, we suggest that patients with highly glycolytic tumours have poorer outcome, supporting the notion of targeting glycolytic tumour cells in prostate cancer through the use of MCT inhibitors.Pertega-Gomes N. and Sousa S. received fellowships from the Portuguese Foundation for Science and Technology (FCT), refs. SFRH/BD/61027/2009, and PTDC/SAU-MET/113415/2009, respectively. Felisbino S. received a fellowship from the Sao Paulo Research Foundation (FAPESP) ref. 2013/08830-2 and 2013/06802-1. We thank the core facilities at the Cancer Research UK Cambridge Institute led by James Hadfield (Genomics), Matt Eldridge (Bioinformatics) and Allen Hazelhurst (BRU). We also thank the support and critical advice on the project given by Christian Frezza and Marco Sciacovelli from The MRC Cancer Cell Unit and Professor Rui Henrique from Portuguese Institute of Oncology for providing samples from patients with metastatic prostate cancer.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/path.454

Extracellular matrix in Staphylococcus epidermidis biofilms: a consequence of bacterial production or cell wall degradation?

Staphylococcus epidermidis is a leading pathogen accounting for nosocomial infections. The ability to form biofilms is considered the major virulence factor of this bacterium. The hallmark of this type of infection is the presence of an extracellular polymeric matrix that, in the case of S. epidermidis biofilms, is mainly constituted by an N-acetylglucosamine polymer. We have identified a subpopulation of bacteria that we believe to be the responsible for the extracellular matrix accumulation in S. epidermidis biofilms as they have comparative significant higher amount of surface N-acetylglucosamine. Flow cytometric evaluation of cell wall permeability and transmission electronic microscopy are highly suggestive of primary wall degradation in these bacteria. In overall, these results suggest that the extracellular matrix in S. epidermidis biofilms is a consequence of the degradation of the bacteria cell wall and that propide iodium should be used with care when used as a marker for bacteria dead in biofilms

Management of infection by the Zika virus

A panel of national experts was convened by the Brazilian Infectious Diseases Society in order to organize the national recommendations for the management of zika virus infection. The focus of this document is the diagnosis, both clinical and laboratorial, and appropriate treatment of the diverse manifestations of this infection, ranging from acute mild disease to Guillain-Barré syndrome and also microcephaly and congenital malformations.1

Toxic Effects of Domoic Acid in the Seabream Sparus aurata

Neurotoxicity induced in fish by domoic acid (DA) was assessed with respect to occurrence of neurotoxic signs, lethality, and histopathology by light microscopy. Sparus aurata were exposed to a single dose of DA by intraperitoneal (i.p.) injection of 0, 0.45, 0.9, and 9.0 mg DA kg−1 bw. Mortality (66.67 ± 16.67%) was only observed in dose of 9.0 mg kg−1 bw. Signs of neurological toxicity were detected for the doses of 0.9 and 9.0 mg DA kg−1 bw. Furthermore, the mean concentrations (±SD) of DA detected by HPLC-UV in extracts of brain after exposure to 9.0 mg DA kg−1 bw were 0.61 ± 0.01, 0.96 ± 0.00, and 0.36 ± 0.01 mg DA kg−1 tissue at 1, 2, and 4 hours. The lack of major permanent brain damage in S. aurata, and reversibility of neurotoxic signs, suggest that lower susceptibility to DA or neuronal recovery occurs in affected individuals