Diagnosis,Burden and Mortality of Pneumocystis jirovecii Pneumonia in Venezuela

Current Fungal Infection Reports - The aim of this work is to contribute to the knowledge of diagnosis, burden, and mortality of pneumocystosis or Pneumocystis jirovecii pneumonia (PCP) in...     

Variation in trophic resources in female South American sea lions at a small geographic scale

Difference among colonies in the population structure of otariids can be driven by philopatry and/or by specializations in the foraging ecology of females. In northern Patagonia, the South American sea lion (SASL) shows some degree of spatial genetic structure among colonies from north and south zones. This study aims to explore the isotopic niche of SASL females in the last period of the pregnancy from different colonies of northern Patagonia and to consider whether the fine scale genetic spatial structuring is potentially related to variation in trophic resources. Stable isotope analysis was performed on 101 skin samples of newborn pups in 10 colonies, as a proxy for the feeding ecology of their mothers. Differences among colonies in the metrics studied revealed the plasticity of the species and support individual trophic specialization of SASL females at a small geographic scale. Also, significant differences were found in all isotopic metrics between the north and south zones. Several hypotheses were proposed to explain the differences in SASL females' isotope values (e.g., use of different foraging areas or prey, isotopic baseline variation). Nonetheless, further research is needed to better understand the relation between fine scale genetic structuring and the foraging ecology of SASL females.     

Bacteriocinogenic Potential of Bacillus amyloliquefaciens Isolated from Kimchi,a Traditional Korean Fermented Cabbage

Bacteriocin production is considered a favorable property for various beneficial cultures. In addition to their potential as biopreservatives, bacteriocins are also promising alternatives for the control of multidrug-resistant pathogens and the inhibition of some viruses and cancer cells. The objective of this study was to screen and characterize a bacteriocin-producing strain with the aim of its future application for control of Listeria monocytogenes, an important food-borne pathogen. A total of 22 potentially bacteriocinogenic strains active against L. monocytogenes ATCC15313 were isolated from locally produced kimchi through a three-level approach. Pure cultures were obtained according to good microbiological practices and differentiated through RAPD-PCR using the primers OPL01, OPL09, and OPL11. Altogether, 5 strains were selected for further study. Specific focus was given to strain ST05DL based on its specific inhibitory activity against L. monocytogenes ATCC15313, while not affecting different strains belonging to the genera Lactobacillus, Pediococcus, Leuconostoc, and Weissella, most of which are beneficial microorganisms. The strain ST05DL was identified as Bacillus amyloliquefaciens based on its sugar fermentation profile obtained through API50CHB analysis and 16S rRNA partial sequencing. The antimicrobial compound produced by B. amyloliquefaciens ST05DL was found to be sensitive to pepsin and α-chymotrypsin, evidence of its proteinaceous nature. The presence of skim milk, NaCl, Tween 80, glycerol, and SDS did not affect the antimicrobial activity. The addition of 20% cell-free supernatant (CFS) obtained from a 24-h culture of B. amyloliquefaciens ST05DL to an exponentially growing culture of L. monocytogenes ATCC15313 successfully inhibited the test microorganisms during the monitored 10-h incubation. Optimal bacteriocin production by B. amyloliquefaciens ST05DL was observed during the stationary phase at 12 h (800 AU/mL) and remained stable for the next 15 h. The ratio between live and dead cells during this period was 74.37% and 25.66%, respectively, as determined by flow cytometry. The presence of the virulence genes hblA, hblB, hblC, nheA, nheB, and nheC was not detected in the total DNA of B. amyloliquefaciens ST05DL, and the strain was resistant only to ampicillin out of 10 tested antibiotics. Future evaluation of expressed bacteriocin/s by B. amyloliquefaciens ST05DL (amino acid sequence, molecular mass, cytotoxicity, detailed mode of action, etc.), will be the next step in the characterization and its potential application as biopreservative and/or pharmaceutical product.

     

Towards an understanding of the role of intrinsic protein disorder on plant adaptation to environmental challenges

Intrinsic protein disorder is an interesting structural feature where fully functional proteins lack a three-dimensional structure in solution. In this work, we estimated the relative content of intrinsic protein disorder in 96 plant proteomes including monocots and eudicots. In this analysis, we found variation in the relative abundance of intrinsic protein disorder among these major clades; the relative level of disorder is higher in monocots than eudicots. In turn, there is an inverse relationship between the degree of intrinsic protein disorder and protein length, with smaller proteins being more disordered. The relative abundance of amino acids depends on intrinsic disorder and also varies among clades. Within the nucleus, intrinsically disordered proteins are more abundant than ordered proteins. Intrinsically disordered proteins are specialized in regulatory functions, nucleic acid binding, RNA processing, and in response to environmental stimuli. The implications of this on plants’ responses to their environment are discussed.     

Expression of miR-34a and miR-15b during the progression of cervical cancer in a murine model expressing the HPV16 E7 oncoprotein

Journal of Physiology and Biochemistry - The high-risk human papillomavirus (HR-HPV) E7 oncoprotein appears to be a major determinant for cell immortalization and transformation altering critical...     

Climatic and socio-economic factors supporting the co-circulation of dengue,Zika and chikungunya in three different ecosystems in Colombia

Dengue, Zika and chikungunya are diseases of global health significance caused by arboviruses and transmitted by the mosquito Aedes aegypti, which is of worldwide circulation. The arrival of the Zika and chikungunya viruses to South America increased the complexity of transmission and morbidity caused by these viruses co-circulating in the same vector mosquito species. Here we present an integrated analysis of the reported arbovirus cases between 2007 and 2017 and local climate and socio-economic profiles of three distinct Colombian municipalities (Bello, Cúcuta and Moniquirá). These locations were confirmed as three different ecosystems given their contrasted geographic, climatic and socio-economic profiles. Correlational analyses were conducted with both generalised linear models and generalised additive models for the geographical data. Average temperature, minimum temperature and wind speed were strongly correlated with disease incidence. The transmission of Zika during the 2016 epidemic appeared to decrease circulation of dengue in Cúcuta, an area of sustained high incidence of dengue. Socio-economic factors such as barriers to health and childhood services, inadequate sanitation and poor water supply suggested an unfavourable impact on the transmission of dengue, Zika and chikungunya in all three ecosystems. Socio-demographic influencers were also discussed including the influx of people to Cúcuta, fleeing political and economic instability from neighbouring Venezuela. Aedes aegypti is expanding its range and increasing the global threat of these diseases. It is therefore vital that we learn from the epidemiology of these arboviruses and translate it into an actionable local knowledge base. This is even more acute given the recent historical high of dengue cases in the Americas in 2019, preceding the COVID-19 pandemic, which is itself hampering mosquito control efforts.     

Lipid and protein oxidation in hepatic homogenates and cell membranes exposed to bile acids

Cholestasis occurs in a variety of hepatic diseases and causes damage due to accumulation of bile acids in the liver. The aim was to investigate the effect of several bile acids, i.e. chenodeoxycholic, taurochenodeoxycholic, deoxycholic, taurodeoxycholic, ursodeoxycholic, lithocholic and taurolithocholic (TLC), in inducing oxidative damage. Hepatic tissue of male Sprague-Dawley rats was incubated with or without 1 mM of each bile acid, with or without 0.1 mM FeCl₃ and 0.1 mM ascorbic acid for the purpose of generating free radicals. Several bile acids increased lipid and protein oxidation, with TLC being the most pro-oxidative (657% and 175% in homogenates and 350% and 311% in membranes, respectively). TLC also enhanced iron-induced oxidative stress to lipids (21% in homogenates and 29% in membranes) and to proteins (74% in membranes). This enhancement was dose- and time-dependent and was reduced by melatonin. These results suggest that bile acids differentially mediate hepatic oxidative stress and may be involved in the physiopathology of cholestasis.     

Intestinal perfusion indicates high reliance on paracellular nutrient absorption in an insectivorous bat Tadarida brasiliensis

Flying vertebrates have been hypothesized to have a high capacity for paracellular absorption of nutrients. This could be due to high permeability of the intestines to nutrient-sized molecules (i.e., in the size range of amino acids and glucose, MW 75–180 Da). We performed intestinal luminal perfusions of an insectivorous bat, Tadarida brasiliensis. Using radio-labeled molecules, we measured the uptake of two nutrients absorbed by paracellular and transporter-mediated mechanisms (l-proline, MW 115 Da, and d-glucose, MW 180 Da) and two carbohydrates that have no mediated transport (l-arabinose, MW 150 Da, and lactulose, MW 342 Da). Absorption of lactulose (0.61 ± 0.06 nmol min^? 1 cm^? 1) was significantly lower than that of the smaller arabinose (1.09 ± 0.04 nmol min^? 1 cm^? 1). Glucose absorption was significantly lower than that of proline at both nutrient concentrations (10 mM and 75 mM). Using the absorption of arabinose to estimate the portion of proline absorption that is paracellular, we calculated that 25.1 ± 3.0% to 66.2 ± 7.8% of proline absorption is not transporter-mediated (varying proline from 1 mM to 75 mM). These results confirm our predictions that 1) paracellular absorption is molecule size selective, 2) absorption of proline would be greater than glucose absorption in an insectivore, and 3) paracellular absorption represents a large fraction of total nutrient absorption in bats.     

Phosphitylation of Primary Carboxamides. Synthesis of Peptide-Oligonucleotide Conjugates with Acylphosphoramidate Linkages

Abstract

N-acylphosphoramidates can be obtained from the reaction of phosphitylated primary carboxamides and an alcohol in the presence of an acid catalyst such as tetrazole and subsequent oxidation. The reaction is useful for the preparation of peptide-oligonucleotide conjugates.