Interactions between zinc and mitochondria during neuronal injury

Zinc is a ubiquitous heavy metal that binds to proteins involved in critical cellular processes. Apart from its necessary role, excessive release of intracellular free zinc (Zn) is neurotoxic under stressed conditions characteristic of ischemic or epileptic neuronal injury. Our earlier results indicated that Zn-induced cell death is exacerbated in neurons compared to supporting neuroglia, suggesting that astrocytes have means to upregulate Zn buffering mechanisms, i.e. the Zn-binding protein metallothionein (MT). The first aim of this dissertation sought to address whether MT can effectively maintain Zn levels at a non-toxic minimum. From these studies, we have identified a dichotomous role for MT - protective as a Zn buffering agent and detrimental as an oxidant-labile source for toxic Zn. Previous studies demonstrated the role of Zn as a mitochondrial toxin. Although it has been widely speculated that Zn is taken up by the mitochondrial calcium uniporter, the evidence is not entirely convincing. In the second specific aim, we addressed the specific hypothesis that mitochondrial Zn uptake occurs though the uniporter. Using a novel model involving isolated mitochondria pre-incubated with a Zn-selective fluorophore and attached to glass coverslips, we demonstrated for the first time direct visualization of mitochondrial Zn transport. The third specific aim addresses the importance of mitochondria as dynamic intracellular ATP factories, whose intracellular trafficking is critical for neuronal viability. We hypothesized that elevated Zn would attenuate mitochondrial trafficking. Our results revealed that Zn inhibited mitochondrial movement at pathophysiological levels. Intriguingly, acute activation of phosphotidyl inositol 3-kinase was implicated in both Zn-mediated movement inhibition and toxicity, providing a novel role for this traditionally pro-survival signaling pathway.In summary, this dissertation identifies intracellular targets for Zn-mediated neurotoxicity. We specifically emphasize the relevance of mitochondria as a Zn target under two circumstances which are critically dependent on the Zn concentrations established - direct mitochondrial interactions that may involve Zn transport, and indirect mitochondrial interactions that affect intracellular mitochondrial trafficking

Effect Of Oestradiol On Mouse Vaginal Epithelium

Oestradiol which induces the proliferation of the vaginal epithelium is used in the oestrogen replacement therapy for menopausal and postmenopausal disorders. The exact onset of induced cell proliferation and recovery to the controlled level has not been reported before. Hence this study was done in ovariectomised mice and the period of cellular response to ethinyl estradiol, a semisynthetic ester (0.025mg/kg) was recorded. The vaginal epithelium was studied for histological changes and incidence of mitotic figures. The onset of proliferation started at 4h after exposure and reached its maximum at 32h and declined gradually thereafter to reach the base level at 60h

Anti (Q, L)-Fuzzy Subhemirings of a Hemiring

In this paper, an attempt has been made to study the algebraic nature of an anti (Q, L)-fuzzy subhemirings of a hemi ring

Water quality studies of Hoskerehalli lake of Bangalore, Karnataka

The aim of the current study was to evaluate the status of the Hoskerehalli lake water with respect to different physicochemical parameters [pH, temperature, total dissolved solids (TDS), turbidity, electrical conductivity (EC), total hardness (TH), alkalinity, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), phosphate, sulphate, nitrate and potassium] during the year 2005. These parameters were compared with water quality standards to indicate probable pollution. However, the overall water quality of the lake remained within the safe limits throughout the study period. Correlation coefficient matrix between each parameter were estimated to throw light on relationship between different physicochemical parameters under investigation, few parameters like pH - temperature (r = 0.712), TDS - turbidity (r = 0.800), TDS - conductivity (r = 0.988), turbidity - conductivity (r = 0.781), temperature - alkalinity (r = 0.822), sulphate - potassium (r = 0.724) showed good positive correlation. The lake water quality is good and fit for irrigation and fish culture purpose

Evaluation of Bacteriological Water Quality, Bangalore-In View of Public health.

From a public health perspective, access to sufficient amounts of clean and safe drinking water is a crucial issue. The provision of good quality household drinking water is often regarded as an important means of improving health. The study was undertaken to analyze the bacterial water quality in Bangalore district, Karnataka. The bacteriological analysis was carried out using the multiple tube technique (MPN- Most Probable Number) for detection of faecal coliform and subsequently organisms present in the sample of water were identified following standard methods. The identified organisms include E. coli, Staphylococcus species, Citrobacter species, Enterobacter, Klebsiella pneumonia, Proteus species, Pseudomonas, Serratia species. 60% of the isolated organism being of the family Enterobacteriaceae. The total heterotrophic plate count (THPC) gave a range of 1.5*104 to 2.2*104 CFU/ml while the total coliform plate count (TCPC) gave a range of 2*103 to 8.3*103 CFU/ml. The presumptive faecal coliform ranged between 0-180 coliform per 100 ml. E. coli / fecal coliform were detected in 60 % of the water sample

Evaluation of the Microbial Pollution of Water in Ramasandra Lake, Bangalore, Karnataka and Assessment of Multiple Antibiotic Resistance among Escherichia Coli

An experiment was designed to examine microbiology of water samples of Ramasandra Lake and further assess the occurance of the multiple antibiotic resistance of E coli. Analysis of the water samples obtained from the lake indicates high microbial and fecal contamination with microbial load in order of 105 and MPN >1800/100ml. Collected water samples from four stations were screened for the E coli to assess their resistance to 10 different antibiotics. Of the 14 E coli isolates 0% were susceptible to all antibiotics used. The isolates were found resistance to penicillin and tetracycline (100%). Among the 10 antibiotics tested, four pattern of antibiotics resistance were obtained and all of them were multiple antibiotic resistance with the number of antibiotics ranging from 2 to 7. The result indicates the developing antibiotic resistant E coli may be a serious threat on public health, aquatic organisms and environment

New Metric Based Algorithm for Test Vector Generation in VLSI Testing

A new algorithm for test-vector-generation (TVG) for combinational circuits has been presented for testing VLSI chips. This is done by defining a suitable metric or distance, in the space of all input vectors, between a vector and a set of vectors. The test vectors are generated by suitably maximising the above distance. Two different methods of maximising the distance are suggested. Performances of the two methods for different circuits are presented and compared with the random method of TVG. It was observed that method B is superior to the other two methods. Also, method A is slightly better than method R

A New Feature Extraction Approach to Extract Area of Expertise from Resumes to Augment the Hiring Process

Text Feature extraction is a process of detecting and discovering promising data from a large unordered textual data set. The main objective of the feature extraction process is to unearth the promising data and transmit them in to acceptable format to help in decision making. With the ever evolving digital technology number of resumes posted everyday seeking for a job increases steeply and this voluminous data intricate the recruitment firms to identify the right candidate for the right job. The main objective of this paper is to deals with a new feature extraction approach using ranking based frequent text occurrences to extract promising texts from the resume dataset and reduces the hiring agencies manual work considerably, reduces the dimensionality of the data to a larger extent and thereby reduces the running or execution time and memory footprints required largely when compared with the existing approaches

STUDY OF VOLTAGE STRESSES INSIDE REGENERATIVE DRIVE

This paper investigates the effect of voltage stress on the voltage insulation components inside a regenerative active-front-end adjustable-speed drive (ASD). It shows that a high potential voltage insulation issue may exist on various components inside the ASD and cause earlier failures. A simplified system model to describe this phenomenon is described, and the voltage stresses of different components inside the ASD under different grounded conditions and filter capacitor are analyzed. It is concluded that among different grounding systems, a high-resistance grounded system gives minimum stress. Appropriately, designing the insulation components is critical to protect the drive