Immunological studies of human placentae: complement components in pre-eclamptic chorionic villi.

Forty human placentae were studied by immunofluorescence for the presence of complement (C) components C1q, C4, C3d, C6 and C9 with the use of characterized antisera. The tissues were grouped as control placentae from 20 normal pregnancies and 20 from cases of pre-eclampsia (PE): the PE samples were sub-grouped as being obtained from patients with mild or severe PE. All of the C components studied were found in the same distribution for test and control samples, but statistical analysis of each pattern of distribution revealed that the deposition of C1q, C3d and C9 were increased in PE as compared to normal tissues. This impression was strengthened by the finding that the deposition of these C components was further increased when chorionic villus immunopathology was compared between mild and severe PE. These data indicate that immunological mechanisms are operating in PE chorionic villi, and they suggest that, among other mechanisms, immune processes may be operative in the pathophysiology of this clinical disease, and that more studies along these lines are in order to rule either in or out this possibility.     

Effects of (-)-epicatechin, a flavonoid on lipid peroxidation and antioxidants in streptozotocin-induced diabetic liver, kidney and heart

The present study was designed to elucidate the antioxidant effect of (-)-epicatechin in streptozotocin (STZ)-induced diabetes in rats. Intraperitoneal administration of (-)-epicatechin at doses of 15 and 30 mg/kg to diabetic rats for a period of 35 days resulted in a significant decrease in blood glucose, thiobarbituric acid reactive substances and hydroperoxides and a significant increase in the concentration of glutathione and the activities of catalase, superoxide dismutase and glutathione peroxidase. (-)-Epicatechin at a dose of 30 mg/kg was found to be more effective. Administration of insulin to diabetic rats normalized the changes caused by STZ.     

LC determination of glimepiride and its related impurities

Five impurities in glimepiride drug substance were detected and quantified using a simple isocratic reverse phase HPLC method. For the identification and characterization purpose these impurities were isolated from a crude reaction mixture of glimepiride using a normal phase HPLC system. Based on the spectroscopic data like NMR, FTIR, UV and MS these impurities were characterized and used as impurity standards for determining the relative response factor during the validation of the proposed isocratic reverse phase HPLC method. The chromatographic separation was achieved on a Phenomenex Luna C8 (2) 100 Å, 5 μm, 250 mm × 4.6 mm using a mobile phase consisting of phosphate buffer (pH 7.0)–acetonitrile–tetrahydrofuran (73:18:09, v/v/v) with UV detection at 228 nm and a flow rate of 1 ml/min. The column temperature was maintained at 35 °C through out the analysis. The method has been validated as per international guidelines on method validation and can be used for the routine quality control analysis of glimepiride as active pharmaceutical ingredient (API).     

Ncm-D-aspartate: a novel caged D-aspartate suitable for activation of glutamate transporters and N-methyl-D-aspartate (NMDA) receptors in brain tissue

The D-isomer of aspartate is both a substrate for glutamate transporters and an agonist of N-methyl-D-aspartate (NMDA) receptors. To monitor the behavior of these receptors and transporters in intact tissue we synthesized a new photo-labile analogue of D-aspartate, N-[(6-nitrocoumarin-7-yl)methyl]-D-aspartic acid (Ncm-D-aspartate). This compound was photolyzed rapidly (t(1/2)=0.11 micros) by UV light with a quantum efficiency of 0.041 at pH 7.4. In acute hippocampal slices, photolysis of Ncm-D-aspartate by brief (1 ms) exposure to UV light elicited rapidly activating inward currents in astrocytes that were sensitive to inhibition by the glutamate transporter antagonist DL-threo-beta-benzyloxyaspartic acid (TBOA). Neither Ncm-D-aspartate nor the photo-released caging group exhibited agonist or antagonist activity at glutamate transporters, and Ncm-D-aspartate did not induce transporter currents prior to photolysis. Glutamate transporter currents were also elicited in cerebellar Purkinje cells in response to photolysis of Ncm-D-aspartate. Photo-release of D-aspartate from Ncm-D-aspartate did not induce alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate receptor or metabotropic glutamate receptor (mGluR) currents, but triggered robust NMDA receptor currents in neurons; Ncm-D-aspartate and the photolzyed caging group were similarly inert at NMDA receptors. These results indicate that Ncm-D-aspartate can be used to study NMDA receptors at excitatory synapses and interactions between transporters and receptors in brain tissue.     

Intralenticular bimanual irrigation: aspiration for subluxated lens in Marfan's syndrome

We describe a new technique of aspiration of subluxated lens in young patients with Marfan's syndrome. Two small circular anterior capsulorhexis (1.5 mm to 2.0 mm) openings were created, and bimanual irrigation/aspiration was performed by introducing the irrigation cannula through 1 capsular opening and the aspiration cannula through the other. The irrigation cannula served the dual purpose of hydrating the lens matter and holding the lens in central position to ensure complete aspiration of the lens matter. The lens capsule was later removed and anterior vitrectomy performed by a vitrectomy cutter. This new technique of intralenticular irrigation/aspiration is effective and safe in performing lens aspiration in extensively dislocated crystalline lens in Marfan's syndrome.     

Glutathione depletion enhances the formation of endogenous cyclic DNA adducts derived from t-4-hydroxy-2-nonenal in rat liver

Earlier, we detected the cyclic adducts of deoxyguanosine (dG) derived from t-4-hydroxy-2-nonenal (HNE), a long chain alpha,beta-unsaturated aldehyde (enal) product from oxidation of omega-6 polyunsaturated fatty acids, in tissue DNA of rats and humans as endogenous DNA damage. Recent evidence implicates the cyclic HNE adducts in human liver carcinogenesis. Because glutathione (GSH) protects against oxidative stress, we undertook a study to examine the effect of GSH depletion on the HNE-derived cyclic adducts in vivo. Four F344 rats were administered L-buthionine-(S,R)-sulfoximine (BSO), a potent inhibitor of GSH biosynthesis, at 10 mM in drinking water for 2 weeks. Rats in the control group were given water only. Livers were harvested, and each liver was divided into portions for GSH and DNA adduct analyses. The BSO treatment depleted hepatic GSH by 77%; the GSH levels were reduced from 6.3 +/- 0.3 in the control rats to 1.5 +/- 0.1 micromol/g tissues in the treated group. The formation of HNE-dG adducts, analyzed by an HPLC-based 32P-postlabeling assay, was increased by 4-fold, from 6.2 +/- 2.2 nmol/mol dG in liver DNA of control rats to 28.5 +/- 16.1 nmol/mol dG in the rats treated with BSO (p <0.05). The formation of 8-oxodG in liver DNA was also increased as a result of BSO treatment, although the increase was not statistically significant. These results further support the endogenous origin of HNE-dG adducts and, more importantly, indicate a critical role that GSH plays in protecting against in vivo formation of the promutagenic cyclic DNA adducts derived from HNE.     

Activated clotting time during cardiopulmonary bypass: is repetition necessary during open heart surgery?

We evaluated the need of activated clotting time monitoring and efficacy of heparinization protocol in 100 patients undergoing open heart surgery. Patients were anticoagulated with 300 or 400 units.kg(-1) heparin, based on their heparin sensitivity assessed at 5 min by activated clotting time. One-third of the initial dose was repeated at 90 min and thereafter hourly until completion of cardiopulmonary bypass. Patients who attained an activated clotting time of > 350 seconds at 5 min were included. Activated clotting time was repeated every 30 min. A time of < 350 seconds or presence of clot in the surgical field/extracorporeal circuit was considered failure of the protocol. Cardiopulmonary bypass was performed using a membrane oxygenator, non-pulsatile flow, hypothermia and crystalloid/blood priming solution. At 5 min, 94 patients had activated clotting time of > 350 seconds, 6 were < 350 seconds. At predetermined time intervals of 30 min, up to 210 min, 406 activated clotting time measurements were above 400 seconds and 40 were between 350 and 400 seconds. No clot was observed in the surgical field or extracorporeal circuit. This anticoagulation protocol ensures adequate anticoagulation during hypothermic cardiopulmonary bypass. With this protocol, only one activated clotting time at 5 min after heparin administration is required and essential; subsequent monitoring is not necessary.     

Breast cancer stage at time of detection in women with systemic lupus erythematosus

Mounting evidence suggests an increased cancer risk in several autoimmune diseases, including systemic lupus erythematosus (SLE). However, greater scrutiny for cancer in subjects with chronic disease (compared to the general population) might explain this apparent association. If so, one would expect cancers in SLE to be diagnosed at earlier stages than in the general population. This might be particularly evident in cancers where screening is available, such as breast cancer. We linked the University of Pittsburgh lupus cohort with the Pennsylvania Cancer Registry to determine the frequency distribution for stage at diagnosis of invasive breast cancers in the SLE subjects. Data on staging of cancers occurring in the general population of Pennsylvania were obtained from The US Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute. A lower percentage of women with SLE presented with localized breast cancer (nine of the 16, 56.2%) compared to the general population of women (63.5%). Although not definitive, this evidence suggests that cancers in SLE are not necessarily diagnosed at earlier stages than in the general population.