Methanesulfonyl fluoride, an acetylcholinesterase inhibitor, attenuates simple learning and memory deficits in ischemic rats

Methanesulfonyl fluoride (MSF), a highly selective CNS inhibitor of acetylcholinesterase, has been recently demonstrated to promote improvement in cognitive performance in patients with senile dementia of Alzheimer type. Because a similar cognitive impairment may accompany stroke, we investigated in the present study whether treatment with MSF could produce beneficial effects in adult rats subjected to an experimental stroke model. Sprague-Dawley rats received transient 60 min intraluminal occlusion of the right middle cerebral artery (MCAo) and were given i.p. injections of either MSF (1 mg/kg at 24 and 48 h post-MCAo and 0.3 mg/kg thereafter every other day) or the vehicle, peanut oil, for 4 weeks. Behavioral tests and biochemical assays were performed at 28 days post-surgery. MSF treatment produced about 90% inhibition of acetylcholinesterase in the brain. Ischemic animals that received the vehicle displayed significant elevated body swing biased activity (84.8 +/- 10%) and significantly prolonged acquisition (398 +/- 62 s) and shortened retention (79 +/- 26 s) of the passive avoidance task. Interestingly, while the ischemic animals that received the MSF exhibited elevated body swing biased activity (87.7 +/- 8%), they performed significantly better in the passive avoidance task (255 +/- 36 s and 145 +/- 18 s in acquisition and retention) than the vehicle-treated animals. Moreover, whereas brains from both groups of animals revealed similar extent and degree of cerebral infarction, the MSF-treated ischemic animals showed more intense immunoreactivity, as well as a significantly higher number (10-15% increase) of septal choline acetyltransferase-positive cells than the vehicle-treated ischemic animals. These results show that MSF, possibly by preserving a functional cholinergic system, attenuated stroke-induced deficits in a simple learning and memory task.     

The use of Epstein-Barr virus transformation for the establishment of class II positive cord blood cells for use in analysis of maternal sera

The use of Epstein-Barr virus transformed cord blood cells to detect maternal antibodies to neonatal class II DR and DQ antigens and to allotype the reacting cells is described.     

Endogenous reactivation of Epstein-Barr virus infections.

In a prior systematic community survey, 20 adults were found to have antibodies to viral capsid antigen (VCA) and early antigen (EA) OF Epstein-Barr virus (EBV) in serum. The presence of the latter antibody suggested a recent response to EBV. In the present study the significance of antibody to EA was more extensively evaluated by examination of the sera of these adults for the presence of EBV-specific IgM antibodies (EBV-IgM) and antibodies to EBV nuclear antigen (EBVNA). Sera of a matched group of adults with antibodies to VCA but without antibodies to EA were compared with those of the 20 adults with antibodies to EA (anti-EA-positive). In the anti-EA-positive group, 19 specimens of serum contained EBV-IgM, 16 contained elevated titers of antibodies to VCA, and 20 contained antibodies to EBVNA. The sera of the matched group had neither detectable EBV-IgM nor elevated titers of antibodies to VCA; however, all sera had antibodies to EBVNA. None of the individuals gave a history of an infectious mononucleosis-like illness. It was suggested that the majority, if not all, of the anti-EA-positive group were manifesting a host immune response to endogenous reactivation of latent EBV. It is of interest that the presence of EBV-IgM was part of this response.     

A clinical trial with Alice/R-75 strain,live attenuated serum inhibitor-resistant intranasal bivalent influenza A/B vaccine

A clinical trial was conducted with Alice/R-75 strain live attenuated intranasal influenza A/B vaccine. With double blind control 88 adult volunteers were administered 2 doses of Alice/R-75 vaccine, 93 volunteers received one dose of Alice/R-75 vaccine and one dose placebo solution and 94 subjects were administered 2 doses of placebo solution. Twenty-three other subjects received Alice strain monovalent influenza A vaccine. For comparison, data from 21 subjects who received monovalent intranasal R-75 strain influenza B in two doses is included. The vaccine was generally well tolerated. Four-fold serum hemagglutination-inhibiting (HAI) antibody titer rises to A/England/42/72 occurred in 39% of the monovalent Alice strain vaccinees; in contrast 18% of those given 2 doses of bivalent Alice/R-75 vaccine and 11% of those given 1 dose of bivalent vaccine had similar four-fold HAI antibody titer rises. HAI antibody titer rises to influenza B/Hong Kong/72 occurred in 38% of R-75 strain monovalent vaccinees, 14% of Alice/R-75 2-dose vaccinees and 11% of Alice/R-75 one dose vaccinees. An epidemic of influenza at the onset of the study made evaluation of the efficacy of the vaccine impossible.This study was supported by a grant from Smith, Kline and French Laboratories, Philadelphia, Pennsylvania     

Primary Epstein-Barr virus infections in children.

During a serioepidemiologic survey of a community, 13 (6.2%) of 209 children were found to be experiencing a current or recent primary Epstein-Barr virus (EBV) infection. The sera contained elevated antibody titers to viral capsid antigen of EBV, antibodies to early antigen (EA) of EBV, and specific IgM. The frequency of primary infections was highest in the first decade of life. The primary EBV infections were usually asymptomatic. The antibody to EA was directed predominantly to the R component. A heterophil antibody response was not detected.     

Detection,treatment and prevention of endodontic biofilm infections: what’s new in 2020?

Abstract

Endodontic disease, a biofilm infection of the root canal space, is a significant cause of dental morbidity worldwide. Endodontic treatment, or root canal treatment, as it is commonly known is founded on the ability to eradicate microbial biofilm infection and prevent re-infection of the highly complex root canal space. Despite many “advances” in clinical endodontics we have seen little improvement in outcomes. The aim of this critical review paper is to provide a contemporary view of endodontic microbiology and biofilm polymicrobiality, provide an understanding of the host response, and how together these impact upon clinical treatment. Ultimately, it is intended to provide insight into novel opportunities and strategies for the future diagnostics, treatment, and prevention of endodontic disease.     

Direct and indirect effects of zinc oxide and titanium dioxide nanoparticles on the decomposition of leaf litter in streams

As the production of metallic nanoparticles has grown, it is important to assess their impacts on structural and functional components of ecosystems. We investigated the effects of zinc and titanium nanoparticles on leaf decomposition in freshwater habitats. We hypothesized that nanoparticles would inhibit the growth and activity of microbial communities leading to decreased decomposition rates. We also hypothesized that under natural light, the nanoparticles would produce reactive oxygen species that could potentially accelerate decomposition. In the lab, whole Ficus vasta leaves were placed in containers holding one liter of stream water and exposed to either 0, 1, 10 or 100 mg/L of ZnO or TiO₂ nanoparticles for six weeks (referred to as Exp. 1). We measured leaf mass loss, microbial metabolism, and bacterial density at 2, 4, and 6 weeks. In a second experiment (referred to as Exp. 2), we measured the effects of light and 10 and 100 mg/L ZnO or TiO₂ nanoparticles on leaf mass loss, bacterial density and the bacterial and fungal community diversity over a 2 week period. In Experiment 1, mass loss was significantly reduced at 10 and 100 mg/L after 6 weeks and bacterial density decreased at 100 mg/L. In Experiment 2, there was no effect of ZnO nanoparticles on leaf mass loss, but TiO₂ nanoparticles significantly reduced mass loss in the dark but not in the light. One possible explanation is that release of reactive oxygen species by the TiO₂ nanoparticles in the light may have increased the rate of leaf decomposition. Bacterial and fungal diversity was highest in the dark, but nanoparticles did not reduce overall diversity.

     

Comparative study of dacryocystorhinostomy with and without intraoperative application of Mitomycin C

Aims and objectives

To compare the outcome of dacryocystorhinostomy surgery with and without the intraoperative use of Mitomycin C.

Methods

Our study is a prospective comparative case study in which 50 patients of primary acquired nasolacrimal duct obstruction were divided on the basis of random sampling into the conventional dacryocystorhinostomy group and the Mitomycin C group in which Mitomycin C 0.2 mg/ml was used intraoperatively. Patients were followed on 1st postoperative day, 1st, 3rd, 6th weeks, 3rd and 6th months. Patient symptoms and satisfaction were noted. Patency of lacrimal passage was assessed by lacrimal syringing and tear meniscus height was recorded on each follow-up.

Results

At the end of 6 months of follow-up, 96% of patients were asymptomatic in the Mitomycin C group whereas 80% patients in the conventional group were asymptomatic. On lacrimal syringing 24 (96%) eyes had patent passage in the Mitomycin C group where as only 1 (4%) patient had complete block with regurgitation of mucopurulent fluid. In the conventional group 20 (80%) eyes had patent passage, 4 (16%) eyes had complete block with regurgitation of mucopurulent fluid and 1 (4%) eye had partially patent passage on lacrimal syringing. Out of 25 eyes, 24 had normal tear meniscus height, and 1 had high tear meniscus height in the Mitomycin C group in comparison to the conventional group in which out of 25 eyes 20 eyes had normal, 1 had moderate and 4 eyes had high tear meniscus height. Intraoperative and postoperative complications in both the groups were identical.

Conclusion

Although the difference between the two groups was not statistically significant, a distinctly higher success was achieved in patients undergoing dacryocystorhinostomy with intra operative Mitomycin C as compared to conventional dacryocystorhinostomy.     

The prevalence and predictors of stigma amongst people living with HIV/AIDS in the Western Province

The aim of the present study was determine the extent to which internalized and enacted stigma is experienced by people living with HIV/AIDS and to establish correlates of such experiences. A convenience sample of 400 HIV-positive participants was selected from three health clinics in the Cape Town area. Respondents' experiences of internalized and enacted stigma were investigated using the HIV/AIDS Stigma Instrument - PLWA (HASI-P). Overall, 28% of respondents endorsed more than one item addressing internalized stigma and 8% endorsed more than one item on any of the four subscales measuring enacted stigma. Male respondents (OR = 0.52, CI = 0.92-0.99), younger respondents (OR = 0.52, CI = 0.29-0.94), and those respondents who had been living with HIV longer were less likely to experience internalized stigma. More educated respondents (OR = 1.19, CI = 1.02-1.39) experienced more internalized stigma than those with less education No demographic characteristics predicted enacted stigma in this particular population. There are a number of possible reasons for low reports of HIV-related stigma, including having access to treatment and not disclosing HIV status.