Tissue distribution of a plasmid DNA encoding Hsp65 gene is dependent on the dose administered through intramuscular delivery

In order to assess a new strategy of DNA vaccine for a more complete understanding of its action in immune response, it is important to determine the in vivo biodistribution fate and antigen expression. In previous studies, our group focused on the prophylactic and therapeutic use of a plasmid DNA encoding the Mycobacterium leprae 65-kDa heat shock protein (Hsp65) and achieved an efficient immune response induction as well as protection against virulent M. tuberculosis challenge. In the present study, we examined in vivo tissue distribution of naked DNA-Hsp65 vaccine, the Hsp65 message, genome integration and methylation status of plasmid DNA. The DNA-Hsp65 was detectable in several tissue types, indicating that DNA-Hsp65 disseminates widely throughout the body. The biodistribution was dose-dependent. In contrast, RT-PCR detected the Hsp65 message for at least 15 days in muscle or liver tissue from immunized mice. We also analyzed the methylation status and integration of the injected plasmid DNA into the host cellular genome. The bacterial methylation pattern persisted for at least 6 months, indicating that the plasmid DNA-Hsp65 does not replicate in mammalian tissue, and Southern blot analysis showed that plasmid DNA was not integrated. These results have important implications for the use of DNA-Hsp65 vaccine in a clinical setting and open new perspectives for DNA vaccines and new considerations about the inoculation site and delivery system.     

Guanine nucleotides can activate the insulin-stimulated phosphodiesterase in liver plasma membranes

The insulin-stimulated cyclic AMP phosphodiesterase from liver plasma membranes is shown to be activated upon incubation with guanine nucleotides in the presence of ATP. The non-hydrolysable analogue of ATP, adenylyl imidodiphosphate failed to substitute for ATP in achieving activation. GTP, its non-hydrolysable analogues p[NH]ppG and GTP-gamma-S, as well as GDP, all elicited activation. It is suggested that guanine nucleotides, and probably insulin, exert their effect on this enzyme through a distinct species of guanine nucleotide regulatory protein.     

Glutathione and glutathione-related enzymes in busulfan treated rat lens

Glutathione (GSH) and GSH-related enzymes, glutathione reductase (GR), gamma-glutamyl cysteine synthetase (gamma-GCS), gamma-glutamyl transpeptidase (gamma-GTP), glutathione S-transferase (GST) and adenosine triphosphatase (ATPase) enzymes were analysed to study the effect of busulfan on the defence mechanisms of the lens. All these enzymes were found to increase significantly except GSH which showed only 7.9% increase as compared to controls in precataractous stage. These results affirm that busulfan is capable of evoking a response from the enzymes involved in the various pathways of GSH enabling the lens to prolong its clarity. The cataractous lenses showed significant decrease in all these parameters. Here, the impairment of the defense mechanism (GST, GR) and the total ATPase may be attributed to the cumulative action of the drug which can react with -SH groups of these enzymes, ultimately causing opacification.     

Characteristics and outcomes of hospital admissions for COVID-19 and influenza in the Toronto area

BACKGROUND:Patient characteristics, clinical care, resource use and outcomes associated with admission to hospital for coronavirus disease 2019 (COVID-19) in Canada are not well described.METHODS:We described all adults with COVID-19 or influenza discharged from inpatient medical services and medical–surgical intensive care units (ICUs) between Nov. 1, 2019, and June 30, 2020, at 7 hospitals in Toronto and Mississauga, Ontario. We compared patient outcomes using multivariable regression models, controlling for patient sociodemographic factors and comorbidity level. We validated the accuracy of 7 externally developed risk scores to predict mortality among patients with COVID-19.RESULTS:There were 1027 hospital admissions with COVID-19 (median age 65 yr, 59.1% male) and 783 with influenza (median age 68 yr, 50.8% male). Patients younger than 50 years accounted for 21.2% of all admissions for COVID-19 and 24.0% of ICU admissions. Compared with influenza, patients with COVID-19 had significantly greater in-hospital mortality (unadjusted 19.9% v. 6.1%, adjusted relative risk [RR] 3.46, 95% confidence interval [CI] 2.56–4.68), ICU use (unadjusted 26.4% v. 18.0%, adjusted RR 1.50, 95% CI 1.25–1.80) and hospital length of stay (unadjusted median 8.7 d v. 4.8 d, adjusted rate ratio 1.45, 95% CI 1.25–1.69). Thirty-day readmission was not significantly different (unadjusted 9.3% v. 9.6%, adjusted RR 0.98, 95% CI 0.70–1.39). Three points-based risk scores for predicting in-hospital mortality showed good discrimination (area under the receiver operating characteristic curve [AUC] ranging from 0.72 to 0.81) and calibration.INTERPRETATION:During the first wave of the pandemic, admission to hospital for COVID-19 was associated with significantly greater mortality, ICU use and hospital length of stay than influenza. Simple risk scores can predict in-hospital mortality in patients with COVID-19 with good accuracy.

International studies report that patients admitted to hospital with coronavirus disease 2019 (COVID-19) have high rates of critical illness and mortality.^1–5 Two small Canadian case series have described care for critically ill patients with COVID-19 and found mortality rates of up to 25%.^6,7 However, outcomes of patients admitted to hospital for COVID-19 in Canada are not well described, particularly outside of intensive care units (ICUs). Case fatality rates for COVID-19 vary dramatically worldwide,⁸ and outcomes of patients admitted to hospital for COVID-19 in Canada may differ from other countries because of differences in populations, public health and health care systems.Seasonal influenza is a useful comparator for COVID-19^9–11 as it is another respiratory virus, familiar to the general public, with high rates of morbidity and mortality. The purpose of this study was to describe patient characteristics, resource use, clinical care and outcomes for patients admitted to hospital with COVID-19 in Ontario, Canada, using influenza as a comparator. We also validated the performance of various prognostic risk scores for in-hospital mortality among patients with COVID-19.     

Mitochondrial DNA variation and genetic structure in populations of Drosophila melanogaster

The understanding of the genetic structure of a species can be improved by considering together data from different types of genetic markers. In the past, a number of worldwide populations of Drosophila melanogaster have been extensively studied for several such markers, including allozymes, chromosomal inversions, and quantitative characters. Here we present results from a study of restriction- fragment-length polymorphisms of mitochondrial DNA (mtDNA) in 92 isofemale lines from many of the same geographic populations of D. melanogaster. Eleven restriction enzymes were used, of which four revealed restriction-site polymorphism. A total of 24 different haplotypes were observed, of which 18 were unique to single populations. In many populations, the unique haplotypes have reached high frequency without being observed in neighboring populations. A Wagner parsimony tree reveals that mutationally close variants show geographical clumping, suggesting local differentiation of mtDNA in populations. The Old-World and the New-World populations are differentiated, with the predominant Old-World haplotype being virtually absent from the New World. These results contrast with those for the nuclear genes, in which many loci show parallel clines in different continents, and suggest a common origin of D. melanogaster populations in North America.      

中国高山ping亚属（Subgerus Alticola）的系统类与分布

高山ｐｉｎｇ亚属广布于中亚山地，即从喜马拉雅山、兴都库库会经帕米尔、天山、西茂而至图瓦、抗爱山和贝加尔湖一带。中国过去仅记录２种：银色高山ｐｉｎｇ（Ａｌｔｉｃｏｌａ ａｒｇｅｎｔａｔｃｓ Ｓｅｖｅｒｔｓｏｖ；有时定作劳氏高山ｐｉｎｇＡ．ｒｏｙｌｅｉ的一亚种）和斯氏高山ｐｉｎｇ。本文依据形态学资料和采用判别函数分析的方法，对该亚属进行了研究。我们认为中国高山ｐｉｎｇ至少有３个以上的物种存在，现概述于