Bloodstream Infection of a Cancer Patient by Cystobasidium minutum: A Case Report and Literature Review

Mycopathologia - Emergent fungal infections are uncommon conditions which frequently lead to death. To our knowledge, only a few cases of invasive infection by...     

Fixation probabilities for the Moran process with three or more strategies: general and coupling results

We study fixation probabilities for the Moran stochastic process for the evolution of a population with three or more types of individuals and frequency-dependent fitnesses. Contrary to the case of populations with two types of individuals, in which fixation probabilities may be calculated by an exact formula, here we must solve a large system of linear equations. We first show that this system always has a unique solution. Other results are upper and lower bounds for the fixation probabilities obtained by coupling the Moran process with three strategies with birth–death processes with only two strategies. We also apply our bounds to the problem of evolution of cooperation in a population with three types of individuals already studied in a deterministic setting by Núñez Rodríguez and Neves (J Math Biol 73:1665–1690, 2016). We argue that cooperators will be fixated in the population with probability arbitrarily close to 1 for a large region of initial conditions and large enough population sizes.

     

Measuring the structural impact of mutations on cytochrome P450 21A2, the major steroid 21-hydroxylase related to congenital adrenal hyperplasia

Abstract

Congenital adrenal hyperplasia is an inherited autosomal recessive disorder related to deficient cortisol synthesis. The deficiency of steroid 21-hydroxylase (cytochrome P450 21A2), an enzyme involved in cortisol synthesis, is responsible for ～95% of cases of congenital adrenal hyperplasia. This metabolic disease exhibits three clinical forms: salt-wasting, simple virilizing, and non-classical form, which are divided according to the degree of severity. In the present study, structural and mutational analyses were performed in order to identify the structural impact of mutations on cytochrome P450 21A2 and correlate them with patient clinical severity. The following mutations were selected: arginine-356 to tryptophan (R356W), proline-30 to leucine (P30L), isoleucine-172 to asparagine (I172N), valine-281 to leucine (V281L), and the null mutation glutamine-318 (Q318X). Our computational approach mapped the location of residues on P450 and identified their implications on enzyme electrostatic potential mapping to progesterone and heme binding pockets. Using molecular dynamics simulations, we analyzed the structural stability of ligand binding and protein structure, as well as possible conformational changes at the catalytic pocket that leads to impairment of enzymatic activity. Our study sheds light on the impact structural mutations have over steroid 21-hydroxylase structure-function in the cell.

Communicated by Ramaswamy H. Sarma     

Correction to: Coccidioidomycosis in a Pediatric Patient

Mycopathologia - A correction to this paper has been published: https://doi.org/10.1007/s11046-021-00559-9     

The role of regioselective hydroxylation on toxicity of diclofenac and related derivatives

ABSTRACT

Diclofenac and related derivatives become more toxic after biotransformation reactions in the body by electron or hydrogen transfers. The structure–reactivity study on regioselective hydroxylation of diclofenac acid was elucidated by using quantum chemistry calculations at level of DFT/B3LYP/6-31G(d,p). HOMO, ionisation potential, bond dissociation energy, and spin density distributions were used as chemical reactivity parameters. Also, some properties are related to lumiracoxib and fenclofenac. The higher flexibility of lumiracoxib can be responsible for the increase of COX₂ selectivity. Diphenyl-amine moiety is responsible for their potent antioxidant capacity. Chloro atoms have a strong effect under electron transfer capacity when compared to acetic acid group. Hydroxylation for the 5-hydroxydiclofenac is more favoured in either electron or hydrogen transfers. Both hydroxylation increased the electron donation and antioxidant capacity. These properties were observed to the fenclofenac derivatives and can be related to their toxicity by redox mechanism.     

Arundic Acid (ONO-2506) Attenuates Neuroinflammation and Prevents Motor Impairment in Rats with Intracerebral Hemorrhage

Cellular and Molecular Neurobiology - Intracerebral hemorrhage (ICH) is a severe stroke subtype caused by the rupture of blood vessels within the brain. Increased levels of S100B protein may...     

Frequency and molecular characterisation of Entamoeba histolytica,Entamoeba dispar,Entamoeba moshkovskii,and Entamoeba hartmanni in the context of water scarcity in northeastern Brazil

This study aimed to estimate the frequency, associated factors, and molecular characterisation of Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, andEntamoeba hartmanni infections. We performed a survey (n = 213 subjects) to obtain parasitological, sanitation, and sociodemographic data. Faecal samples were processed through flotation and centrifugation methods.E. histolytica, E. dispar, E. moshkovskii, and E. hartmanni were identified by nested-polymerase chain reaction (PCR). The overall prevalence of infection was 22/213 (10.3%). The infection rate among subjects who drink rainwater collected from roofs in tanks was higher than the rate in subjects who drink desalinated water pumped from wells; similarly, the infection rate among subjects who practice open defecation was significantly higher than that of subjects with latrines. Out of the 22 samples positive for morphologically indistinguishableEntamoeba species, the differentiation by PCR was successful for 21. The species distribution was as follows: 57.1% to E. dispar, 23.8% to E. histolytica, 14.3% toE. histolytica and E. dispar, and 4.8% E. dispar and E. hartmanni. These data suggest a high prevalence of asymptomatic infection by the group of morphologically indistinguishable Entamoeba histolytica/dispar/moshkovskiicomplex and E. hartmanni species. In this context of water scarcity, the sanitary and socioenvironmental characteristics of the region appear to favour transmission.     

Feeding habits of the cuttlefish <Emphasis Type="Italic">Sepia</Emphasis> <Emphasis Type="Italic">officinalis</Emphasis> during its life cycle in the Sado estuary (Portugal)

The importance of cephalopods in marine ecosystems is well recognized as they serve as important predators and prey in many food chains. During a 1-year period, cuttlefish were monthly sampled in five areas throughout the Sado estuary, and the stomachs of 445 individuals were examined. Significant changes in the diet according to their life stage were revealed, but similar food habits were presented by males and females. Juvenile individuals (the smaller ones with no visible distinct gonads) preyed mainly upon small crustaceans, while the immature ones (maturity stages I and II) had the most diverse diet with brachyurans as the major prey group. The mature individuals (maturity stages III and IV) showed a clear preference for larger crabs and fishes. Although the cuttlefish are known for their opportunistic feeding behaviour, a preference for some prey according to length and behaviour could be perceived during this study. Seasonal differences in the diet were mostly due to the variation of individuals according to their maturity stage during the year.