On the re-isolation and taxonomic study of Candida viswanathii Viswanathan et Randhawa 1959

Summary A detailed taxonomic study of a new isolate ofCandida viswanathii from sputum is reported.     

On the occurrence of two new species of Trichophyton in Indian soils

Summary Two new species ofTrichophyton, T. indicum andT. evolceanui, isolated from soil in India by the hair baiting technique, are described.T. indicum is characterized by its flat colony and delicately roughened microconidia. It is common and widely distributed in soil in India. T. evolceanui can be distinguished fromT. indicum by its heaped and folded colony on tomato juice agar and its echinulate and obovate microconidia which are consistently wider than those ofT. indicum on the various culture media tested.T. evolceanui also differs fromT. indicum in producing perforating organs on hair in vitro soil culture. It has restricted occurrence in Indian soils.     

Both Paraoxonase-1 Genotype and Activity Do Not Predict the Risk of Future Coronary Artery Disease; the EPIC-Norfolk Prospective Population Study

Background

Paraoxonase-1 (PON1) is an antioxidant enzyme, that resides on high-density lipoprotein (HDL). PON1-activity, is heavily influenced by the PON1-Q192R polymorphism. PON1 is considered to protect against atherosclerosis, but it is unclear whether this relation is independent of its carrier, HDL. In order to evaluate the atheroprotective potential of PON1, we assessed the relationships among PON1-genotype, PON1-activity and risk of future coronary artery disease (CAD), in a large prospective case-control study.

Methodology/Principal Findings

Cases (n = 1138) were apparently healthy men and women aged 45–79 years who developed fatal or nonfatal CAD during a mean follow-up of 6 years. Controls (n = 2237) were matched by age, sex and enrollment time. PON1-activity was similar in cases and controls (60.7±45.3 versus 62.6±45.8 U/L, p = 0.3) and correlated with HDL-cholesterol levels (r = 0.16, p<0.0001). The PON1-Q192R polymorphism had a profound impact on PON1-activity, but did not predict CAD risk (Odds Ratio [OR] per R allele 0.98[0.84–1.15], p = 0.8). Using conditional logistic regression, quartiles of PON1-activity showed a modest inverse relation with CAD risk (OR for the highest versus the lowest quartile 0.77[0.63–0.95], p = 0.01; p-trend = 0.06). PON1-activity adjusted for Q192R polymorphism correlated better with HDL-cholesterol (r = 0.26, p<0.0001) and more linearly predicted CAD risk (0.79[0.64–0.98], p = 0.03; p-trend = 0.008). However, these relationships were abolished after adjustment for HDL (particles-cholesterol-size) and apolipoproteinA-I (0.94[0.74–1.18], p-trend = 0.3).

Conclusions/Significance

This study, shows that PON1-activity inversely relates to CAD risk, but not independent of HDL, due to its close association with the HDL-particle. These data strongly suggest that a low PON1-activity is not a causal factor in atherogenesis.     

Modeling recapitulates the heterogeneous outcomes of SARS-CoV-2 infection and quantifies the differences in the innate immune and CD8 T-cell responses between patients experiencing mild and severe symptoms

SARS-CoV-2 infection results in highly heterogeneous outcomes, from cure without symptoms to acute respiratory distress and death. Empirical evidence points to the prominent roles of innate immune and CD8 T-cell responses in determining the outcomes. However, how these immune arms act in concert to elicit the outcomes remains unclear. Here, we developed a mathematical model of within-host SARS-CoV-2 infection that incorporates the essential features of the innate immune and CD8 T-cell responses. Remarkably, by varying the strengths and timings of the two immune arms, the model recapitulated the entire spectrum of outcomes realized. Furthermore, model predictions offered plausible explanations of several confounding clinical observations, including the occurrence of multiple peaks in viral load, viral recrudescence after symptom loss, and prolonged viral positivity. We applied the model to analyze published datasets of longitudinal viral load measurements from patients exhibiting diverse outcomes. The model provided excellent fits to the data. The best-fit parameter estimates indicated a nearly 80-fold stronger innate immune response and an over 200-fold more sensitive CD8 T-cell response in patients with mild compared to severe infection. These estimates provide quantitative insights into the likely origins of the dramatic inter-patient variability in the outcomes of SARS-CoV-2 infection. The insights have implications for interventions aimed at preventing severe disease and for understanding the differences between viral variants.     

Inheritance of endo-β-1,4-glucanase production in Trichoderma reesei

Abstract Mutants of Trichoderma reesei QM9414 were isolated and characterized with respect to their cellulolytic and auxotrophic markers. Fusion of protoplasts isolated from uninucleate conidia was used to obtain hybrids between different pairs of mutants. Induced haploidization of the hybrids allowed recovery of stable segregants, which were screened for endoglucanase production. Segregants of each cross displayed a range of titers divulging their quantitative nature and polygenic control. Biometrical analysis suggests the involvement of 4–7 operationally recognizable units of function (effective factors) in the overall endoglucanase phenotype. High titer segregants were obtained from most crosses.     

Aneuploidy detection with a short-term hexaploid wheat assay

A new type of assay for the identification of agents causing aneuploidy is described. This assay takes advantage of allohexaploid wheat in which monosomic and nullisomic cell lineages can be genetically detected. The wheat strain used (Neatby's virescens) was homozygous for a pair of recessive alleles (v1) which in homozygous condition interfere with normal pigmentation of the leaves at low temperature whereas at higher temperature nearly normal green color formation is permitted. In a single dose this allele cannot suppress the formation of green color even at low temperature, i.e., it is hemizygous ineffective. This locus is in the short arm of chromosome 3B near the centromere. As a consequence of non-disjunction of this chromosome twin sectors may be detected, in which the monosomic cell lineages appear green whereas the trisomic sectors display with color on a cream-colored background at low temperature. This genetic system can also be used for the detection of deletions or duplications involving the short arm of chromosome 3B, and to some extent the A- and the D-genome homeologues. We have determined the pattern of differentiation of the shoot apex and on that basis we can separate the independent genetic events from reappearance of the sectors of common origin in the successive leaves. Such an understanding of development of the leaf sectors permits a quantitative estimation of the genetic response of the plants to mutagenic factors. We have found that X-rays, gamma-rays, p-fluorophenylalanine, 3-aminotriazole, caffeine, vinblastin sulfate, benzo[a]pyrene and auramine significantly increased aneuploidy, and diethylstilbestrol, sulfacetamide, safrole and dichlorvos caused some increase of sectoring. Cytological data on root tips of irradiated seeds support the interpretation of the mechanism of sector formation in the leaves. The test is simple, fast, inexpensive, and it does not require elaborate facilities or highly trained technicians. The trials were well reproducible during a period of 3 years in 2 laboratories. Therefore we consider the new assay a useful complement to other tests of chemicals or physical agents that may cause non-disjunction and other chromosomal aberrations in human populations.     

Effects of pyrimidine-2-thiol on the ovarian histology of Epilachna vigintioctopunctata (Fabr.) (Coleoptera: Coccinellidae)

The telotrophic ovary of Epilachna vigintioctopunctata is composed of 32-40 ovarioles, each with an apical germarium and a basal vitellarium. The germarium encloses mononucleate and binucleate trophocytes, prefollicular tissue and oogonia, while the vitellarium contains 2-5 oocytes arranged in order of maturity. Definite nutritive cords are absent. When females are exposed to 75 mg 4,4,6-trimethyl-1h, 4H-pyrimidine-2-thiol by contact, the trophocytes and the follicular epithelial cells disintegrate to form dark-staining clumps and thus fail to supply nourishment to the developing oocytes, which consequently remain yolk-less and are ultimately reduced to shrunken masses.