Irfan Zia Qureshi

Expression of sulphonylurea receptor protein in mouse kidney

Abstract The sulphonylurea receptor (SUR) is the site of action for sulphonylurea derivatives such as glibenclamide, which are widely used as oral hypoglycaemic agents. Sulphonylureas have also been shown to affect urine flow and salt excretion by the kidney; therefore, the use of these drugs may have important implications for the pharmacological manipulation of renal salt handling. The purpose of the present investigation was to increase our understanding of the possible role of SUR in the regulation of renal function by determining the distribution of SUR isoforms within mouse kidney. Immunostaining with anti-SUR antisera revealed specific staining of SUR2B in distal nephron segments of mouse kidney. A diffuse, low level staining was observed in proximal tubules in the inner cortical region. No evidence was found for the presence of SUR2B in intra-renal blood vessels. Reverse-transcription polymerase chain reaction and Western blotting experiments indicated that SUR2B is the only known isoform expressed. These data demonstrate that SUR2B in mouse kidney is expressed in tubule regions that are critical in determining renal salt excretion.

Intraperitoneal kisspeptin-10 administration induces dose-dependent degenerative changes in maturing rat testes.

AIMS Kisspeptin, a peptide secreted by hypothalamic neurons, is a critical regulator of reproduction and puberty but its role in the regulation of gonadal maturation in sexually immature males is elusive. The present study investigated the effects of 12 days of pulsatile kisspeptin administration on gonadotropins and testosterone release and maturation of immature male gonads. MAIN METHODS Kisspeptin-10 was administered intraperitoneally at different dosage concentrations (1 μg, 1 ng, and 10 pg) to 5 weeks old prepubertal male rats, twice daily for 12 days. Plasma LH, FSH and testosterone concentrations were measured through competitive-binding radioimmunoassay. Spermatogenesis was studied mainly at stage VII of the spermatogenic cycle through light and electron microscopy. KEY FINDINGS At the end of the treatments plasma LH and testosterone concentrations were reduced significantly at 1ng and 1μg kisspeptin doses (P<0.05; P<0.01). Type A spermatogonia, preleptotene spermatocytes, pachytene spermatocytes, step 7 spermatids, elongated spermatids and daily sperm production decreased significantly (P<0.05). Sertoli cell efficiency and total support capacity of Sertoli cells were reduced at all doses (P<0.05). Meiotic index decreased (P<0.05) at 1 μg dose only, whereas coefficient of mitosis increased at 1 ng and 1 μg (P<0.01) kisspeptin doses. Histologically, degeneration of seminiferous tubules was evident showing tubular necrosis, multinucleated giant cell formation, intratubular vacuolization, widened lumen and deshaped germ cells. Marked ultrastructural changes characterized by thin basal laminae, enlarged intratubular spaces, abnormal acrosome and disrupted germ cells were noticeable. SIGNIFICANCE In conclusion long-term kisspeptin-10 administration negatively regulates gonadal maturation in prepubertal testes.

Dual action spirobicycloimidazolidine-2,4-diones: antidiabetic agents and inhibitors of aldose reductase-an enzyme involved in diabetic complications.

The desired 3-(arylsulfonyl)spiroimidazolidine-2,4-diones were synthesized by reacting spiroiminoimidazolidine-2,4-dione with arylsulfonyl chlorides. Spiroimidazolidine-2,4-dione was in turn synthesized from norcamphor. Structures of the synthesized molecules were established by modern spectroscopic techniques. The synthesized compounds were screened for in vivo antidiabetic activity and aldose reductase inhibition. Compounds 2a, 2b and 2g exhibited excellent dual activity, compound 2a being most prominent. These results reveal that the synthesized compounds may serve as the molecule of choice to treat diabetes and diabetic complications using a single medication.

Passive immunization using purified IgYs against infectious bursal disease of chickens in Pakistan.

Infectious bursal disease (IBD) is an acute and highly contagious disease of young chickens caused by Birnavirus. Mortality of infected birds can be best prevented if injected with antibodies. The present study was an attempt to raise specific hyper-immune polyclonal antibodies against IBD virus in Pakistan. Commercial layers divided into four groups were injected with IBD vaccine subcutaneously according to four different treatment regimens. Eggs were collected daily and antibodies were purified from yolk with dextran sulphate. Titers of antibodies in serum and yolk were evaluated with enzyme linked immunosorbant assay and agar gel precipitation test. Antibody titers were significantly higher in yolk than serum. Eggs collected at 28 days post-vaccination had maximum antibody titers. Of treatment regimens, T3 was found to be most effective for hyperimmunization. Lyophilized antibodies stored at 4℃ did not lose their activity till the end of experiment. IBD virus infected birds were injected with purified antibodies which induced 92% recovery as compared to control birds. The study implicates that the purified antibodies may be useful as a therapeutic agent to cure IBD infected birds.

Tetra primer ARMS-PCR relates folate/homocysteine pathway genes and ACE gene polymorphism with coronary artery disease

Cardiovascular disorders and coronary artery disease (CAD) are significant contributors to morbidity and mortality in heart patients. As genes of the folate/homocysteine pathway have been linked with the vascular disease, we investigated association of these gene polymorphisms with CAD/myocardial infarction (MI) using the novel approach of tetraprimer ARMS-PCR. A total of 230 participants (129 MI cases, 101 normal subjects) were recruited. We genotyped rs1801133 and rs1801131 SNPs in 5′10′ methylenetetrahydrofolate reductase (MTHFR), rs1805087 SNP in 5′ methyltetrahydrofolate homocysteine methyltransferase (MTR), rs662 SNP in paroxanse1 (PON1), and rs5742905 polymorphism in cystathionine beta synthase (CBS). Angiotensin converting enzyme (ACE) insertion/deletion polymorphism was detected through conventional PCR. Covariates included blood pressure, fasting blood sugar, serum cholesterol, and creatinine concentrations. Our results showed allele frequencies at rs1801133, rs1801131, rs1805087 and the ACE insertion/deletion (I/D) polymorphism varied between cases and controls. Logistic regression, after adjusting for covariates, demonstrated significant associations of rs1801133 and rs1805087 with CAD in the additive, dominant, and genotype model. In contrast, ACE I/D polymorphism was significantly related with CAD where recessive model was applied. Gene–gene interaction against the disease status revealed two polymorphism groups: rs1801133, rs662, and rs1805087; and rs1801131, rs662, and ACE I/D. Only the latter interaction maintained significance after adjusted for covariates. Our study concludes that folate pathway variants exert contributory influence on susceptibility to CAD. We further suggest that tetraprimer ARMS-PCR successfully resolves the genotypes in selected samples and might prove to be a superior technique compared to the conventional approach.

Prospective role of ascorbic acid (vitamin C) in attenuating hexavalent chromium-induced functional and cellular damage in rat thyroid.

Occupational exposure to toxic heavy metals may render industrial workers with thyroid-related problems. Here, we examined the role of ascorbic acid (vitamin C) against hexavalent chromium Cr (VI)-induced damage in rat thyroid gland. Potassium dichromate (K2Cr2O7) and ascorbic acid doses were 60 µg and 120 mg kg—1 body wt (intraperitoneally [i.p.]) respectively. Treatment regimens were group I rats, saline treated control; group II, only K2Cr2O7; group III, ascorbic acid 1 hour prior K2Cr2O7; group IV, simultaneous doses of ascorbic acid and K2Cr2O 7, and group V, a combined premix dose of ascorbic acid and K2 Cr2O7 (2:1 ratio). Blood samples were taken before dosing the animals and 48 hours post exposure to determine the serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4) concentrations. Toward end of experiment, rats were sacrificed and thyroid glands were processed to evaluate the extent of cellular insult. Results showed significantly increased TSH and decreased FT3 and FT4 concentrations in groups II, III and IV rats as compared to control levels (p < 0.05). In contrast, in group V rats, serum TSH, FT3 and FT4 concentrations neared control concentrations. Histopathologically, protective effect of ascorbic acid was found in group V rats only, where thyroid gland structure neared control thyroid except the follicular size that was decreased (p < 0.05). Follicular density was no different from control. Basal laminae were intact, interfollicular spaces were normal. Colloid retraction and/or reabsorption were reduced maximally. Epithelial cell height was no different from control; epithelial follicular index increased only 1.3 fold, whereas nuclear-cytoplasmic (N/C) ratio was decreased by 14% only. The study indicates that the ascorbic acid may have the potential to protect thyroid gland from chromium toxicity; however, the study warrants further in-depth experimentation to precisely elucidate this role.

Synthesis, pH dependent photometric and electrochemical investigation, redox mechanism and biological applications of novel Schiff base and its metallic derivatives

A novel Schiff base, 1-((2, 4-dimethylphenylimino)methyl)naphthalen-2-ol abbreviated as (HL) and its four metallic complexes were synthesized and confirmed by 1H and 13C NMR, FTIR, TGA and UV-Visible spectroscopy. Schiff base was also characterized by X-ray analysis. The photometric and electrochemical responses of all the synthesized compounds were investigated in a wide pH range. Structures of the compounds were optimized computationally for the evaluation of different physico-chemical parameters. On the basis of electrochemical results the redox mechanistic pathways of the compounds were proposed. The cytotoxicity analysis on Hela cells revealed that HL and its complexes inhibit cell growth as revealed from their IC50 values (HL):106.7μM, (L2VO): 40.66μM, (L2Sn): 5.92μM, (L2Zn): 42.82 and (L2Co): 107.68μM. The compounds were tested for anti-diabetic, triglyceride, cholesterol, anti-microbial, anti-fungal and enzyme inhibition activities. The results revealed that HL and its complexes are promising new therapeutic options as these compounds exhibit strong activity against cancer cells, diabetics, fungal and microbial inhibition.

Exposure to sub-acute doses of fipronil and buprofezin in combination or alone induces biochemical, hematological, histopathological and genotoxic damage in common carp (Cyprinus carpio L.).

Use of pesticides or insecticides can be highly toxic to aquatic life forms due to leaching and agricultural runoff, rains or flood. Fipronil (FP) is a GABA receptor inhibitor, while buprofezin (BPFN) is an insect growth regulator. Presently, we exposed groups of aquaria acclimated carp fish (Cyprinus carpio) for 96h to sub-lethal concentrations of fipronil (400μgL(-1); 9.15×10(-7)molL(-1)) and buprofezin (BPFN, 100mgL(-1); 1.072×10(-6)molL(-1)) singly or in combination. The extent of damage was assessed at biochemical, hematological, molecular biological and histopathological level. Results obtained in treated fish were compared statistically with those of control non-treated fish and also among treatment groups. Significance level was p<0.05. Compared to control, serum total protein and globulin concentrations decreased significantly (p<0.0001) in fish treated with FP; while albumin concentration remained unaltered with all treatments. Glucose concentration decreased significantly (p<0.002) in fish treated with FP. In contrast, combined FP+BPFN treatment and BPFN treatment caused insignificant elevation of glucose concentration. Hematological assessment demonstrated significant decrease in red blood cell and thrombocyte counts, hemoglobin concentration and hematocrit percent; while white blood cell count showed an increase in all treatment groups (p<0.0001). Blood smears from pesticide treated fish revealed aberrant erythrocyte morphologies which included necrosis, micronuclear formation and hyperchromatosis. DNA laddering assay carried out on whole blood demonstrated excessive smear formation in combined FP+BPFN and BPFN treatment groups but no smear formation was noticeable in FP treated fish. Compared to control, whole blood DNA content increased significantly in the combined FP+BPFN and BPFN treatment groups (p<0.001 and p<0.009). With all treatments histopathological changes observed in the gills were: epithelial uplifting and necrosis of lamellae, lamellar atrophy, disruption of cartilaginous core, fusion and disorganization of lamellae and telangiectasia. In liver these were: karyorrhexis, hepatocellular hypertrophy, nuclear hypertrophy, melanomacrophage aggregates and central vein contraction, while in the kidney: deterioration of glomerulus and dilatation of Bowmans space, dilatation of renal tubules, thyroidisation, altered tubular lumen, nuclear hypertrophy, cellular atrophy, and cellular necrosis were the outcome. Our study revealed that FP and BPFN produce highly toxic effects on fish when given in combination or singly. To our knowledge, this is the first report on toxicity caused by FP and BPFN in single and combined state.

Synthesis, molecular docking and biological evaluation of new thiazolopyrimidine carboxylates as potential antidiabetic and antibacterial agents

Abstract A series of new thiazolopyrimidine analogues were conveniently synthesized by one-pot multicomponent condensation reaction of ethyl acetoacetate, 2-aminothiazole and benzaldehyde substituted with different electron-donating and electron-withdrawing groups, in order to find some more potent antidiabetic and antibacterial drugs. The structures of the synthesized compounds were assigned based on elemental analyses and spectral data. An in vitro effect on total serum concentration of glucose, cholesterol and triglycerides was evaluated in adult male BALB/c mice, compared to two standard drugs “alloxan” and “glibenclamide,” and good results were observed with the presence of –Cl and –Br groups at the para position of the phenyl ring. The antibacterial activities were tested against five bacterial strains, Micrococcus luteus, Salmonella typhimurium, Bacillus subtilis, Bordetella bronchiseptica and Escherichia coli. Most of the compounds showed good to excellent bacterial zone inhibition compared to the reference drug “kanamycin.” An in silico molecular docking was also performed on synthesized compounds to support the experimental findings, which were in good agreement with computational results. The current study is expected to provide useful insights into the design of antidiabetic and antibacterial drugs, and understanding the mechanism by which such drugs interact with RNA and diabetes targets and exert their biochemical action.

Kisspeptin-10 induces dose dependent degeneration in prepubertal rat prostate gland

Kisspeptin peptides mediate their actions through the GnRH loop system. How kisspeptins affect prostate gland in prepubertal male mammals remains elusive.