Regional Membrane Phospholipid Alterations in Alzheimer's Disease

Regional levels of membrane phospholipids [phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC)] were measured in the brain of Alzheimer's disease (AD) and control subjects. The levels of PE-derived and PI-derived total fatty acids were significantly decreased in the hippocampus of AD subjects. Here significant decreases were found in PE-derived stearic, oleic and arachidonic and docosahexaenoic acids, and in PI-derived oleic and arachidonic acids. In the inferior parietal lobule of AD subjects, significant decreases were found only in PE and those decreases were contributed by stearic, oleic and arachidonic acids. In the superior and middle temporal gyri and cerebellum of AD subjects, no significant decreases were found in PC-, PE- and PI-derived fatty acids. The decrease of PE and PI, which are rich in oxidizable arachidonic and docosahexaenoic acids, but not of PC, which contains lesser amounts of these fatty acids, suggests a role for oxidative stress in the increased degradation of brain phospholipids in AD.     

Absence of enantioselectivity in the pharmacodynamics of P450 2B induction by 5-ethyl-5-phenylhydantoin in the male rat liver or in cultured rat hepatocytes

To explore the enantioselectivity of ligand interaction with the putative phenobarbital receptor, the pharmacodynamics of cytochrome P450 2B (CYP2B) induction by racemic 5-ethyl-5-phen-ylhydantoin and its two enantiomers were investigated in the male F344/NCr rat and in cultured adult male rat hepatocytes. Steady-state serum drug concentrations, measured following 14 days of administration of the compounds in the diet (0-1320 ppm, n = 3 rats per group), were used as an approximation of intrahepatocellular drug concentration. The serum xenobiotic concentrations associated with half-maximal hepatic CYP2B induction were 5-10 μM, based on measurement of pentoxy- or benzyloxyresorufin O-dealkylation activities, or immunoreactive CYP2B1 protein. The corresponding potency values in the hepatocyte culture experiments were 8-12 μM, based on measurement of total cellular RNA coding for CYP2B1. In both the in vivo and the hepatocyte culture experiments, the potencies for CYP2B induction were essentially equivalent for the racemate and the individual enantiomers of 5-ethyl-5-phenylhydantion. In the case of this compound, there would appear to be no enantioselectivity for CYP2B induction. This finding may be interpreted as evidence against receptor mediation in the induction of CYP2B activity, although it is also possible that a receptor is involved that does not exhibit enantioselectivity.     

Nonspecific light loss and intrinsic DNA variation problems associated with feulgen DNA cytophotometry.

Nonspecific light loss by the cell-wall-plus-cytoplasm (CWC) can cause a 50% increase in Feulgen absorption units in peanut root-tip nuclei as determined by scanning at 450 nm, whereas this phenomenon is not evident with chicken erythrocytes. A two wavelength scanning method of subtracting nonspecific 450 nm absorption from 550 nm Feulgen absorption values eliminated the nonspecific light loss in CWC, However, the two wavelength scanning method is time consuming and somewhat impractical with a regular scanning microdensitometer such as Vickers M85. Elimination of the problem of nonspecific light loss is suggested by careful determination of background setting with the spot position close to the nucleus in CWC. The accuracy of the CWC background setting method was further tested by comparison with subtraction method. The use of plant nucleis as an internal standard in plant DNA measurements was also evaluated. Significant variation among the replicate slides due to the variation in pine nuclear DNA amounts was observed and plant nuclei generally are not reliable internal standards. Mature chicken erythrocytes are recommended as an internal standard because the cell type and metabolic state is known.     

Promoter Hypermethylation in Tumor Suppressing Genes p16 and FHIT and Their Relationship with Estrogen Receptor and Progesterone Receptor Status in Breast Cancer Patients from Northern India

BACKGROUND: Aberrant DNA methylation has been recognized in human breast carcinogenesis as a common molecular alteration associated with the loss of expression of a number of key regulatory genes. The present study was undertaken to determine whether methylation and expression of p16 and FHIT genes would correlate with the estrogen receptor (ER) and progesterone receptor (PR) status. METHODS: Methylation-specific polymerase chain reaction, messenger RNA (mRNA) expression analysis, immunohistochemistry, and Western blot analysis were performed to study the methylation of p16 and FHIT genes in 351 pairs of malignant/normal breast tissues. We examined the expression of ER and PR in those specimens by immunohistochemistry. Mutations of p16 and FHIT genes in tumors were detected by direct sequencing. RESULTS: The frequency of hypermethylation was 31.9% and 36.8% in p16 and FHIT genes, respectively, and showed significant harmony in concordant hypermethylation (P < .0001). In postmenopausal patients, methylation frequency in both genes is significantly higher in poorly and moderately differentiated tumors. Loss of protein expression of p16 and FHIT in 77 and 74 tumors, respectively, is associated with their methylation status in premenopausal women. CONCLUSION: We did not find any significant differences in tumor-related gene methylation patterns relevant to both ER and PR status of breast tumors.     

Comparative effects of selenate and selenite on growth and biochemical composition of rapeseed (Brassica napus L.)

High levels of selenium can cause adverse effects in plants as well as animals. In a greenhouse experiment, rapeseed (Brassica napus) was grown in an alkaline sandy loam soil treated with different levels of selenate-Se and selenite-Se ranging from 0 to 4 mg kg^?1. Total dry matter yield of selenium-treated rapeseed plants decreased significantly as compared to control plants. Plants were stressed at a very early stage of vegetative growth and produced fewer rosettes and flowers. Plant height and leaf production were negatively affected by selenate-Se. Dry matter of leaves was significantly higher in selenite- than in selenate-treated plants. Selenate-treated plants accumulated 75–160 times more Se in shoots and 2–18 times more in roots as compared to selenite-treated plants at the rosette formation stage, with this difference narrowing at peak flowering stage. Rapeseed leaves were subjected to biochemical analysis at rosette and peak flowering stages. Accumulation of selenium in leaves resulted in a significant increase in lipid peroxidation, chlorophyll, vitamin C and free amino acids, and a decrease in phenols, total soluble sugars and starch concentration.     

PARTAKE Survey of Public Knowledge and Perceptions of Clinical Research in India

Background

A public that is an informed partner in clinical research is important for ethical, methodological, and operational reasons. There are indications that the public is unaware or misinformed, and not sufficiently engaged in clinical research but studies on the topic are lacking. PARTAKE – Public Awareness of Research for Therapeutic Advancements through Knowledge and Empowerment is a program aimed at increasing public awareness and partnership in clinical research. The PARTAKE Survey is a component of the program.

Objective

To study public knowledge and perceptions of clinical research.

Methods

A 40-item questionnaire combining multiple-choice and open-ended questions was administered to 175 English- or Hindi-speaking individuals in 8 public locations representing various socioeconomic strata in New Delhi, India.

Results

Interviewees were 18–84 old (mean: 39.6, SD±16.6), 23.6% female, 68.6% employed, 7.3% illiterate, 26.3% had heard of research, 2.9% had participated and 58.9% expressed willingness to participate in clinical research. The following perceptions were reported (% true/% false/% not aware): ‘research benefits society’ (94.1%/3.5%/2.3%), ‘the government protects against unethical clinical research’ (56.7%/26.3%/16.9%), ‘research hospitals provide better care’ (67.2%/8.7%/23.9%), ‘confidentiality is adequately protected’ (54.1%/12.3%/33.5%), ‘participation in research is voluntary’ (85.3%/5.8%/8.7%); ‘participants treated like ‘guinea pigs’’ (20.7%/53.2%/26.0%), and ‘compensation for participation is adequate’ (24.7%/12.9%/62.3%).

Conclusions

Results suggest the Indian public is aware of some key features of clinical research (e.g., purpose, value, voluntary nature of participation), and supports clinical research in general but is unaware of other key features (e.g., compensation, confidentiality, protection of human participants) and exhibits some distrust in the conduct and reporting of clinical trials. Larger, cross-cultural surveys are required to inform educational programs addressing these issues.     

A quantitative real-time PCR method for absolute telomere length

Telomere shortening is an important risk factor for cancer and accelerated aging. Here we describe the development of a simple and reproducible method to measure absolute telomere length. Based on Cawthon's quantitative real-time PCR (qRT-PCR) assay, our method uses an oligomer standard that can be used to generate absolute telomere length values rather than relative quantification. We demonstrate a strong correlation between this improved method and the "gold standard" of telomere length measurement-terminal restriction fragment analysis (TRF) by Southern hybridization. The capability to generate absolute telomere length values should allow a more direct comparison of results between experiments within and between laboratories.     

Next Generation Sequencing Reveals Regulation of Distinct Aedes microRNAs during Chikungunya Virus Development

Background

Application of genomics and Next Generation sequencing has led to the identification of new class of cellular functional molecules, namely, small RNAs. Of the several classes of ncRNAs (non-coding RNA), microRNAs have been demonstrated to exert determinative influence on various cellular processes. It is becoming abundantly clear that host/vector/pathogen encoded microRNAs impact eventual pathogenesis. In this context, the participation of vector based microRNAs in disease transmission and pathogen development is being investigated intensively. A few studies have highlighted the role of vector encoded microRNAs in pathogen infection. We conducted this study to evaluate the role of host miRNAs upon CHIKV (Chikungunya Virus) infection in an important vector, Aedes albopictus.

Findings

We identified 88 and 79 known miRNAs in uninfected and CHIKV infected Ae. albopictus Singh''s cell line respectively. We further identified nine novel miRNAs in Ae. albopictus. Comparison of the two libraries revealed differential expression of 77 common miRNAs between them. CHIKV infection specifically altered the miRNA profile of a specific set of eight miRNAs. Putative targets of these regulated miRNAs were identified and classified into their pathways.

Conclusions

In our study we have identified and described the profiles of various miRNAs upon CHIKV infection in Ae. albopictus. This investigation provides an insight about cellular modification by miRNAs during CHIKV infection and the results provide leads for identifying potential candidates for vector based antiviral strategies.     

Understanding alternative fluxes/effluxes through comparative metabolic pathway analysis of phylum actinobacteria using a simplified approach

Actinobacteria are known for their diverse metabolism and physiology. Some are dreadful human pathogens whereas some constitute the natural flora for human gut. Therefore, the understanding of metabolic pathways is a key feature for targeting the pathogenic bacteria without disturbing the symbiotic ones. A big challenge faced today is multiple drug resistance by Mycobacterium and other pathogens that utilize alternative fluxes/effluxes. With the availability of genome sequence, it is now feasible to conduct the comparative in silico analysis. Here we present a simplified approach to compare metabolic pathways so that the species specific enzyme may be traced and engineered for future therapeutics.