Default mode network dysfunction in adults with prenatal alcohol exposure

Prenatal alcohol exposure (PAE) is known to cause significant cognitive and attentional dysfunction. Given the relationship between default mode network (DMN) activity and task-related attentional modulation, it is possible that PAE affects activity of this network. In the present study, task-related deactivation as well as structural and resting state functional connectivity of the DMN were examined using diffusional tensor imaging and functional magnetic resonance imaging in non-dysmorphic and dysmorphic PAE populations and compared to healthy controls. The dysmorphic PAE group was found to have reduced DMN deactivation as compared to controls, indicating poorer attentional modulation during the cognitive task. Additionally, structural connectivity and baseline functional connectivity were lower in both PAE groups as compared to controls. Primarily the findings suggest that learning problems seen with PAE may be a combination of general attentional and specific cognitive deficits. A secondary implication is that DMN activity is affected to varying extents depending on the degree of PAE.     

Correlation Between Chemical Composition and Antifungal Activity of the Essential Oils of Eight Cinnamomum. Species

Abstract

Fourteen essential oils hydrodistilled from eight Cinnamomum. (Lauraceae) species (C. pubescens. Kochummen, C. impressicostatum. Kosterm, C. microphyllum. Ridl., C. scortechinii. Gamb., C. rhyncophyllum. Miq., C. cordatum. Kosterm, C. zeylanicum. Blume, and C. mollissimum. Hook f.) were examined for their antifungal activity against six dermatophytes (Trichophyton rubrum, T. mentagrophytes, T. tonsurans, Microsporum canis, M. gypseum., and M. audouini)., one filamentous fungi (Aspergillus fumigatus.), and five strains of yeasts (Candida albicans, C. glabrata, C. tropicalis, C. parapsilosis., and Crytococcus neoformans.) by using the broth microdilution method. The antifungal activities of 13 standard compounds that are prevalent constituents in Cinnamomum. oils were also investigated in an effort to correlate the effectiveness of the oils with those of the components of the oils. The chemical composition of the oils was analyzed by GC and GC-MS. Most of the oils showed moderate to strong activity against the fungi. Among the oils, the leaf and bark oils of C. zeylanicum. showed the highest activity against all the fungi with MIC values of 0.04 to 0.63 μ g μ L^{? 1}. Other oils that gave a strong inhibition on fungal growth were the leaf oil of C. cordatum. and bark and twig oils of C. pubescens. and C. impressicostatum.. Cinnamaldehyde, which was the most abundant component of the bark oil of C. zeylanicum., showed the strongest activity against all the fungi studied. Based on the results of the assay on standard samples, it may be that the high levels of cinnamaldehyde, eugenol, geraniol, benzyl benzoate, and methyl cinnamate in the oils and in combination with the minor components is responsible for the high antifungal activity of the oils.     

Polymorphism and overexpression of HER2/neu among ovarian carcinoma women from Tiruchirapalli, Tamil Nadu, India

Purpose

Alteration and overexpression of HER2 proto-oncogene have been implicated in the carcinogenesis and prognosis of ovarian cancer. We evaluated this hypothesis among women with ovarian carcinoma patients from Tiruchirapalli, Tamil Nadu, India.

Methods

Genomic DNA was extracted from 72 case patients and 288 control subjects and was examined for I655V polymorphism by PCR–RFLP based assay. Immunohistochemistry analysis was carried out in order to study the overexpression of HER2 protein. The observed number of each genotype was compared with that expected for a population in the Hardy–Weinberg equilibrium. In analysing the relation between genotype and overexpression of HER2 protein, Cochran-Mantel–Haenszel statistics was used.

Results

We found that 20.8 % of the case patients and 16.3 % of the control subjects were heterozygous for the Val allele and 10 case patients (13.8 %) and 3 control subjects (1.1 %) were homozygous for this allele (P < 0.001). Compared with women with Ile/Ile genotype, women with Val/Val genotype had an elevated risk of ovarian cancer. The genotype distributions were consistent with the Hardy–Weinberg equilibrium. The risk increased with the number of Val allele and women homozygous for the Val allele had 15-fold (OR = 15.3; 95 %CI = 4.09–57.31) increased risk of cancer. The patients homozygous for the Valine allele showed strong HER2 protein expression.

Conclusion

The results showed that the valine allele may be an indicator of genetic susceptibility to ovarian carcinoma in the study population.     

Carcinogenicity of diethylnitrosamine in vitamin-A-deficient mice

The effect of suboptimal levels of dietary vitamin A on diethylnitrosamine (DEN) carcinogenesis was studied in BALB/c and Swiss mice. Two different dietary regimens were employed to induce vitamin A deficiency and DEN was administered by gavage at 2 dose levels: 0.6 mg/kg as a single dose and 200 mg/kg in 4 divided doses. Shark liver oil (SLO) which was the main source of vitamin A in the standard diet, was deleted in one regimen and reduced to 25% in the other. The mice maintained on the former diet were given a high dose of DEN and those on the latter diet received a low dose. In both strains the deficient mice had a greater tumour incidence than those on standard diet with a marginal reduction in the latent period. At the low level of DEN there was shift in organotrophy, i.e. from liver in controls to lung in the vitamin-A-deficient mice of BALB/c strain. With the higher dose, lung adenomas predominated in deficient as well as control groups in both the strains. Forestomach carcinomas appeared in deficient mice and not in the controls.     

Erythropoietin and cerebral vascular protection： role of nitric oxide

Cerebral vasospasm after subarachnoid hemorrhage (SAH) is a major clinical problem causing cerebral ischemia and infarction. The pathogenesis of vasospasm is related to a number of pathological processes including endothelial damage and alterations in vasomotor function leading to narrowing of arterial diameter and a subsequent decrease in cerebral blood flow. Discovery of the tissue protective effects of erythropoietin (EPO) stimulated the search for therapeutic application of EPO for the prevention and treatment of cerebrovascular disease. Recent studies have identified the role of EPO in vascular protection mediated by the preservation of endothelial cell integrity and stimulation of angiogenesis. In this review, we discuss the EPO-induced activation of endothelial nitric oxide (NO) synthase and its contribution to the prevention of cerebral vasospasm.     

Diethylnitrosamine and acetoxymethyl methylnitrosamine-induced carcinogenesis in mice and vitamin A deficiency

The modulating influence of vitamin A deficiency on carcinogenesis induced by two potent carcinogens, diethylnitrosamine (DEN) and acetoxymethyl methylnitrosamine (AMMN), was studied in BALB/c mice. DEN was administered intragastrically every 30 days at a total dose of 200 mg/kg body weight, split into four doses. AMMN was applied continuously every 14 days on the tongue, at a dose of 2 mg/kg body weight. AMMN and DEN treated animals fed the vitamin A deficient diet had a significantly higher tumor incidence that mice fed the normal diet (p less than 0.05). Studies on the levels of vitamins A, C, B2 and folic acid in the liver and plasma of mice treated with the two carcinogens revealed that both the carcinogens increased vitamin C in both tissues, decreased folic acid and had no effect on vitamin A, while hepatic vitamin B2 was lowered by treatment with AMMN by not by DEN.