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Biomedical subjects

H Kaur

Publications and source records attributed to H Kaur.

At least 19 recordsLinked to original sources
PubMed2006

Residues of DDT and HCH in wheat samples collected from different states of India and their dietary exposure: A multicentre study.

Under a multicentre study conducted by the Indian Council of Medical Research, 1712 samples of wheat grain/flour were collected from urban and rural areas in 11 states representing different geographical regions of India. These samples were analysed for residues of DDT (2,2-bis (p-chlorophenyl)-1,1,1-trichloro ethane) and different isomers of HCH (1,2,3,4,5,6-hexachloro cyclohexane, a mixture of isomers) by gas-liquid chromatography. Residues of DDT were detected in 59.4% of 1080 samples of wheat grain and in 78.2% of 632 samples of wheat flour. Different isomers of HCH were present in about 45-80% of the samples of wheat grain/flour. Medians of DDT and total HCH, respectively, for pooled samples of wheat grain were 0.013 and 0.035 mg kg(-1), while those for wheat flour were 0.01 and 0.02 mg kg(-1). Estimated daily intakes of DDT and different isomers of HCH through the consumption of wheat contaminated at their median and 90th percentiles constituted a small proportion of their acceptable daily intakes. Amongst the pesticide residues analysed, statutory maximum residue limits have been fixed only for gamma-HCH in wheat in India, as 0.1 mg kg(-1) in wheat grain and zero in wheat flour. Residue levels of gamma-HCH exceeded these maximum residue limits in five of 1080 samples of wheat grain and in 340 of 632 samples of wheat flour. The failure to meet the requirement of the gamma-HCH maximum residue limit in large number of wheat flour samples was attributed to the fixation of practically unachievable zero limit. Comparing the previous studies and the present one, the levels of residues of DDT and HCH in wheat were significantly decreased.

Adult↗
PubMed2006

Cell adherence--a determinant of virulence in Yersinia enterocolitica.

The adherence of pathogenic bacteria to eukaryotic cells plays a central role in their ability to colonize the mucosal epithelial surfaces. The adherence by Y. enterocolitica to the mucosal surface of the gut is the initiating event leading to penetration of mucosa. Adhesion of 10 probable pathogenic and one non-pathogenic isolate was studied using ileum and colon epithelial cells of mouse for 90 minutes. Adhesion study revealed that isolates of Y. enterocolitica had a good adhesive property while non pathogenic showed negligible adherence. All isolates showed better adherence to colon epithelial cells. The organism continued to be excreted in faeces up to 8-10 days after oral feeding. Adhesion positive isolates were found to be virulent when tested in mice for diarrhoea and death. Adhesion was found to be thermoregulated.

Animals↗
PubMed2005

Multi-country field trials comparing wash-resistance of PermaNet and conventional insecticide-treated nets against anopheline and culicine mosquitoes.

Insecticide-treated bednets (ITNs) are commonly used as a means of personal protection from malaria transmission by anopheline mosquitoes (Diptera: Culicidae). Long-lasting insecticidal nets (LLINs) have special treatments intended to remain effective after many washes. The present trials assessed the efficacy and wash-resistance of several production batches of PermaNet (polyester net coated with polymer resin containing pyrethroid insecticide deltamethrin 55 mg ai/m2) against malaria vectors in Pakistan, Iran and Tanzania compared to ITNs conventionally treated with alphacypermethrin 15 or 20 mg ai/m2, or deltamethrin 25 or 50 mg ai/m2. Insecticidal efficacy of the nets before and after repeated washing (using W.H.O. recommended and traditional local washing procedures) was monitored through contact bioassays with Anopheles and by experimental hut and outdoor platform tests. Local washing regimes gradually reduced the insecticidal efficacy of conventionally treated nets, but they were not exhausted, even after 21 washes. Using a more rigorous laboratory washing method, insecticide was more readily stripped from conventionally treated nets. PermaNet retained high efficacy after 21 washes, giving more than 97% mortality of Anopheles in contact bioassays with 3-min exposure. Using the more sensitive bioassay criterion of 'median time to knockdown', PermaNet showed no loss of insecticidal activity against Anopheles after washing repeatedly in 2 out of 6 trials; whereas in a further three trials knockdown activity of PermaNet and conventional ITNs declined at comparable rates. Higher mortality levels of Anopheles in contact bioassays did not always translate to superiority in experimental hut or enclosed platform trials. In only one of four comparative field trials did PermaNet out-perform conventional ITNs after washing: this was in the trial of PermaNet 2.0--the product with improved quality assurance. Because PermaNet and conventionally treated nets were both quite tolerant of local washing procedures, it is important in field trials to compare LLINs with conventional ITNs washed an equivalent number of times. Our comparison of PermaNet 2.0 against conventionally treated deltamethrin nets (CTDN) in Pakistan demonstrated superior performance of the LLIN after 20 washes in phase I and phase II bioassays, and this was corroborated by chemical assays of residual deltamethrin. Although PermaNet 2.0 has received WHOPES interim recommendation for malaria control purposes, its performance should be monitored in everyday use throughout its lifespan in various cultural settings to assess its durability and long-term effectiveness for malaria prevention and control. As many millions of conventionally treated nets are already in routine use, and these will require regular re-treatment, programme strategies should be careful to preserve the effectiveness of ITNS before and after establishing the reliability of LLINs in long-term use.

Animals↗
PubMed2005

Activation of natural killer-like YT-INDY cells by oligodeoxynucleotides and binding by homologous pattern recognition proteins.

The present study was designed to examine the binding and signalling effects of single base and CpG dinucleotide phosphodiester (Po) oligodeoxynucleotides (ODN) on the human natural killer (NK)-like cell line (YT-INDY). Single base Po ODN composed of 20-mers of guanosine (dG20), adenosine (dA20), cytosine (dC20) or thymidine (dT20) as well as 'conventional' Po CpG ODN were examined for their ability to bind and activate YT-INDY cells. Binding by dG20 and CpG ODN to YT-INDY cells was saturable and specific. dG20 binding was competitively inhibited by homologous dG20 and heterologous CpG ODN but not by dC20 and dA20. Two different YT-INDY membrane proteins (18 and 29 kDa) were identified by ligand (Southwestern) blotting with biotinylated dG20 and CpG. The specificity of the ODN-binding protein(s) was further confirmed by ODN depletion experiments using a teleost recombinant protein orthologue [nonspecific cytotoxic cells (NCC) cationic antimicrobial protein-1 (ncamp-1)] known to bind CpG and dG20. Cell proliferation and activation studies showed that dG20 and CpG treatment of YT-INDY cells induced cellular DNA synthesis (i.e. G1 to S-phase conversion). This signalling function was accompanied in dG20-treated cells by proliferation 10 h posttreatment. Both dG20 and CpG ODN binding induced a calcium flux in YT-INDY cells within seconds of treatment. These experiments demonstrated that Po single base dG20 and CpG ODN bind to a (potential) new class of cell-surface proteins that mediate the activation of YT-INDY cells.

Adjuvants, Immunologic↗
PubMed2004

Vesicocervical fistula--a rare complication secondary to caesarean section.

We report a case of vesicocervical fistula secondary to caesarean section. This is a rare complication of caesarean section, which was not recognised intraoperatively. Diagnosis was made clinically, radiologically and endoscopically during the post-operative period. Conservative management with indwelling catheterisation for 3 weeks failed. Hence the fistula was repaired surgically by an abdominal approach.

Adult↗
PubMed2004

Single-base oligodeoxyguanosine-binding proteins on nonspecific cytotoxic cells: identification of a new class of pattern-recognition receptors.

The present study was designed to identify a possible new class of pathogen-recognition proteins that bind single-base oligodeoxynucleotide (ODN) ligands. Binding by the teleost natural killer cell equivalent [referred to as nonspecific cytotoxic cells (NCC)] was compared with mammalian cells (mouse RAW264.7 cells and human THP-1 cells). The ODN analysed were composed of 20-mers of guanosine (dG20), adenosine (dA20), thymidine (dT20) or cytosine (dC20). Binding studies first determined the 50% saturation levels for NCC (1.25 microg/ml), RAW264.7 (0.2 microg/ml) and THP-1 (0.8 microg/ml). Binding by dG20 to all the three cell types was saturable. Ligand blots of NCC membrane lysates with biotinylated dG20 revealed two different major molecular weight species (16-18 and 29 kDa) of binding proteins. The 29-kDa protein was identified with the help of Western blot analysis using a polyclonal antibody specific to an NCC antimicrobial protein (ncamp-1). The membrane expression of the 29-kDa ncamp-1 was determined by the binding of surface-biotinylated NCC membrane proteins with digoxigenin dG20 followed by immunoprecipitation using anti-digoxigenin agarose beads. The 29 and 14-18 kDa NCC membrane proteins were cross-reactive using Western blot examination with a polyclonal anti-histone 1 antibody. Function studies revealed that dG20 activated a twofold upregulation of membrane binding by homologous dG20-biotin. dG20 also stimulated NCC-increased membrane expression of NCC receptor protein 1. Additional experiments were performed to determine the DNase sensitivity of the different ODN. dG20 appeared to be more resistant to DNase treatment, compared to dC20, dA20 and dT20. The single-base ODN-binding proteins may represent a new class of pattern-recognition receptors that are involved in innate anti-bacterial resistance mediated by NCC.

Animals↗
PubMed2004

The relationship between temperature and neuronal characteristics.

The purpose of this study was to determine a relationship between surface temperature of the limb and neuronal characteristics of the median and ulnar nerves in non-impaired individuals. Previous literature demonstrates that there is a negative correlation between distal latency and amplitude and temperature while a positive correlation exists between nerve conduction velocity and temperature. It is a common clinical practice to externally manipulate the temperature of a cold limb. Thirty-six participants (21 male, 15 female,) with an age range between 20-38 years old (mean age = 26.6) completed the study. Temperature of the limb was not manipulated by the researchers prior to testing and was measured at the distal wrist crease using a surface probe. Relationship was determined using a Pearson product-moment coefficient of correlation. A significant negative correlation existed for median distal sensory latency (DSL), ulnar DSL, ulnar motor amplitude (CMAP), and ulnar sensory amplitude (SNAP). The investigators conclude that temperature is a factor to consider when performing nerve conduction studies. The researchers suggest using mathematical correction factors to compensate for a cool limb rather than external heating.

Adult↗
PubMed2004

Histopathological and ultrastructural alterations of induced Yersinia enterocolitica infection in mice.

Yersinia enterocolitica is an enteric bacterium and infections by this organism are mostly foodborne. It has been implicated to cause enterocolitis, terminal ilitis. diarrhoea, mesenteric lymphadenitis and arthritis in man. Due to paucity of information regarding histopathological and specially ultrastructural alterations in tissues affected, this study was planned with mice as the experimental model. Nine pathogenic Y.enterocoliticaisolates were used to infect 80 albino mice by oral and intraperitoneal route. Pathological alterations were studied by light and electron microscopy. Histopathological examination of intestines showed severe edema, purulent enteritis, goblet cell hyperplasia infiltration of mononuclear cells, thickening of mucosa and necrosis of the tips of villi. Liver showed congestion, hepatocellular degeneration and necrosis, atrophy of hepatocytes and microabcesses. The lungs revealed congestion, edema, haemorrhage and purulent ronchopneumonia, while kidneys showed mild necrotic changes and bacterial emboli in glomeruli. Ultrastructural changes were indicative of mitochondrial degeneration and their loss in kidneys, membranous degeneration with formation of myelin figures in lungs and disorganization, disruption and bleb formation of microvilli in intestines. Y.enterocolitica caused significant histopathological and ultrastructural alterations in experimentally infected mice. Variation in pathogenicity of different strains of Y.enterocolitica was also observed.

Animals↗
PubMed2003

Attenuation of renal ischemia-reperfusion injury by trimetazidine: evidence of an in vivo antioxidant effect.

Renal ischemia-reperfusion injury constitutes the most common pathogenic factor for acute renal failure and is the main contributor to renal dysfunction in allograft recipients and revascularization surgeries. Many studies have demonstrated that reactive oxygen species play an important role in ischemic acute renal failure. The aim of the present study was to investigate the effects of the synthetic antiischemic agent trimetazidine in a rat model of renal ischemia-reperfusion injury. Renal ischemia-reperfusion was induced by clamping the unilateral renal artery for 45 min followed by 24 h of reperfusion. Trimetazidine (2.5 mg/kg i.p.) was administered 24 and 12 h prior to renal artery occlusion and the same dose was given intravenously 1 h before inducing ischemia. Tissue lipid peroxidation was measured as thiobarbituric acid reacting substances (TBARS) in kidney homogenates. Renal function was assessed by estimating serum creatinine, blood urea nitrogen (BUN), creatinine and urea clearance. Renal morphological alterations were assessed by histopathological examination of hematoxylin-eosin stained sections of the kidneys. Ischemia-reperfusion produced elevated levels of TBARS and deteriorated the renal function as assessed by increased serum creatinine, BUN and decreased creatinine and urea clearance compared with sham operated rats. The ischemic kidneys of rats showed severe hyaline casts, epithelial swelling, proteinaceous debris, tubular necrosis, medullary congestion and hemorrhage. Trimetazidine markedly reduced elevated levels of TBARS and significantly attenuated renal dysfunction and morphological changes in rats subjected to renal ischemia-reperfusion. These results clearly demonstrate the in vivo antioxidant effect and the therapeutic potential of trimetazidine, an anti-ischemic agent, in attenuating renal ischemia-reperfusion injury.

Animals↗
PubMed2003

Systemic concentrations of antioxidants and biomarkers of macromolecular oxidative damage in horses with grass sickness.

REASONS FOR PERFORMING STUDY: The aetiopathogenesis of equine grass sickness (EGS) is unknown. The role of free radical-mediated neuronal damage has not previously been investigated in this condition. OBJECTIVES: To investigate the potential contribution of oxidative damage and antioxidant status to neurodegeneration in EGS. METHODS: Systemic levels of surrogate biomarkers were determined in 10 horses with acute EGS and in 2 control populations; 10 healthy horses co-grazing with the 10 EGS horses at the onset of clinical disease, and 10 healthy mares grazing where EGS has not been reported. RESULTS: EGS horses had alterations in levels of several antioxidants, consistent with oxidative stress, the acute phase response and/or the secondary metabolic complications of EGS. EGS horses had elevated plasma dihydroxyphenylalanine (DOPA) levels. CONCLUSIONS: The elevated DOPA levels probably reflected a generalised disturbance of catecholamine metabolism rather than increased DOPA production via free radical-mediated oxidation of tyrosine. However, there was no evidence of systemic macromolecular oxidative damage. POTENTIAL CLINICAL RELEVANCE: Further work is required to determine whether macromolecular oxidative damage occurring at the neuronal level contributes to EGS.

Animals↗
PubMed2002

Assessment of the carrier status by pedigree analysis in some families from India.

Pedigree analysis is an important tool to assess the carrier status of the females in the families of haemophiliac patients. A study was conducted on 85 families, of which 75 were of haemophilia type A and 10 of haemophilia type B. The probability values of the females being carriers were calculated by the Bayesian method. The results revealed that 45 mothers were genetic obligate carriers and the remaining 40 probable, hence the transmission was of familial nature in 45 families, whereas the remaining 40 were categorized as isolated cases. The probability values of 425 females were calculated and a wide range of probability values ranging from 0.0295 to 1 was observed.

Fathers↗
PubMed2002

Evaluation of the pesticidal potential of the congress grass, Parthenium hysterophorus Linn. on the mustard aphid, Lipaphis erysimi (Kalt.).

Petroleum ether extracts of leaves, stem and inflorescence of Parthenium hysterophorus Linn. at 500, 1000, 2000 and 5000 ppm concentrations were tested in the laboratory for their toxic effects on the mean life span and progeny production of adults of the mustard aphid, Lipaphis erysimi (Kalt.). The investigations revealed a significant decrease in life span and progeny production with treatment. Among the three plant parts tested for their efficacy, the leaf extract showed the most significant effect in causing a dose dependent decline in both the life span and progeny production.

Animals↗
PubMed2001

Cell cycle effects of the phenothiazines: trifluoperazine and chlorpromazine in Candida albicans.

The study demonstrates the in vitro effectiveness of phenothiazine compounds, i.e. chlorpromazine and trifluoperazine against Candida albicans. Anticandidal effect of these drugs is suggested to be because of their interaction with Ca(2+)/calmodulin dependent protein phosphorylation. 3H-thymidine uptake studies revealed that both these compounds affect the DNA synthesis along with decrease in activities of nuclear calmodulin (CaM) and Ca(2+)/calmodulin dependent protein kinase (CaMPK). Failure in cell growth was due to defect in CaM mediated cell cycle arrest. Flow cytometric analysis showed that progression through G(1) and mitotic phase was affected when cells after alpha-factor arrest were grown in the presence of chlorpromazine or trifluoperazine. These drugs also produced significant decline in the cellular lipids and phospholipids. 14C-acetate incorporation studies further substantiated these results. We suggest that chlorpromazine or trifluoperazine affect the cell cycle through DNA synthesis (S phase) and cell division phases which are governed by calmodulin and Ca(2+)/calmodulin dependent protein phosphorylation and lipids and phospholipids appear to be additional targets of phenothiazine compounds in C. albicans. These results will have important significance in the development of new anticandidal compounds.

Antifungal Agents↗