Effect of pentoxifylline on the pharmacokinetics of rosiglitazone in Wistar rats

The aim of this study was to investigate the effect of pentoxifylline (PTX), an antiplatelet agent, on the pharmacokinetics of rosiglitazone (RSG) in rats. Pharmacokinetic parameters of RSG were determined in rats after oral administration (3 mg/kg/day) in the presence and absence of PTX (10 mg/kg) 3 times daily. Compared to control animals, rats pretreated with PTX for 7 days had a decrease in RSG peak plasma concentration (Cmax) of 19% with no change in the values of the area under the concentration-time curve (AUC). Alternatively, rats coadministered single-dose PTX did not show any differences from control with regard to RSG Cmax and AUC parameters. The time to peak concentration (tmax) of RSG was significantly increased in rats pretreated with PTX under both single- and multiple-dose conditions, whereas the elimination half-life (t1/2) of RSG was increased only with multiple-dose PTX pretreatment. In conclusion, the presence of PTX was found to cause a slight decrease in the oral exposure of RSG in rats. Concurrent use of PTX with RSG therefore needs to be appropriately evaluated for proper dose adjustments in humans.     

Role of the lateral septal noradrenergic system in the elaboration of male sexual behavior in rats

The study was aimed at investigating the possible involvement of noradrenergic mechanisms in the lateral septum (LS) for elaboration of male sexual behavior in rats. In this study, norepinephrine (NE), yohimbine (YOH), isoproterenol (ISOP), propranolol (PROP), saline (SAL) and dimethyl sulfoxide (DMSO) were injected bilaterally in the LS in six different groups of sexually active male rats, and various components of sex behavior were recorded. The application of NE (3 microg) and alpha(2)-antagonist YOH (1 microg) produced a stimulation of most of the components of male sexual behavior, and there was increase in sexual arousal as well as performance. The microinfusion of nonspecific beta-agonist ISOP (2 microg) also produced a stimulation of copulatory behavior whereas beta-antagonist PROP (2 microg) produced an inhibition. The stimulation of male sexual behavior by YOH application at the LS could be due to an increased release of NE by its blocking effect on presynaptic alpha(2)-receptors. These results suggest that the noradrenergic system in the LS has stimulatory effect upon male sexual behavior, probably acting through beta-receptors.     

Use of chlorophyll fluorescence in metal-stress research: a case study with the green microalga Scenedesmus

Metal toxicity on the photosystem II (PS II) photochemistry of the green microalga Scenedesmus obliquus was investigated in vivo using a pulse-amplitude-modulated fluorometer. The results demonstrated that the test metals (copper, chromium, nickel, cadmium, and zinc) inhibited PS II photochemistry substantially, which was clearly evident for F0, Fv/Fm, qN, and qP following 12h of metal exposure, whereas Fm, Fv/2, and F0/Fv depicted significant alteration after only 1h of treatment. Thus, metals are not only found to affect the initial and maximal fluorescence, maximum quantum yield, photochemical and nonphotochemical quenching, and plastoquionone pool but the water-splitting apparatus was also significantly altered under metal stress. Among all these fluorescence characteristics, the F0/Fv registered the highest sensitivity to all the five test metals, thus indicating that the water-splitting apparatus of the oxidizing side of PS II is the primary site of action of toxic metals. This study therefore, concludes that F0/Fv ratio can be used as a powerful tool in metal-stress research.     

Sequential study of the IgA system in relapsing IgA nephropathy

Cellular and immunochemical parameters of the IgA system were studied in 15 subjects with IgA nephropathy (IgAN) and 15 agematched controls. In IgAN remission no abnormalities of the IgA system were detectable by the methods used. In IgAN relapse, [macroscopic hematuria associated with upper respiratory tract infection (URTI) (N = 6)] there were rises in IgA-bearing B-lymphocytes (three of six), T helper/suppressor cell ratio (six of six) and pokeweed mitogen-induced IgA production (four of six). Total serum and salivary IgA were unchanged. Serum IgA profile (HPLC-ELISA) showed increases in polymer IgA (three of six). No such changes were found during URTI in controls. These findings support the view that an exaggerated IgA response to mucosal antigen challenge initiates glomerular damage and hematuria in IgAN.     

Evaluation of direct agglutination test (DAT) and ELISA for serodiagnosis of visceral leishmaniasis in India

The direct agglutination test (DAT) and the enzyme-linked immunosorbent assay (ELISA) were used for serodiagnosis of parasitologically confirmed Indian visceral leishmaniasis (VL) cases. All the sera of VL cases were positive by both the methods. DAT titres of VL cases were greater than or equal to 1:3,200, and ELISA values were greater than or equal to 0.55 1:400 dilution. In the control group, sera of widely prevalent diseases of India, such as leprosy, tuberculosis, malaria, and liver cirrhosis, were included. Both tests could discriminate between VL and other patients of the control group. The sera of post-kala-azar dermal leishmaniasis (PKDL) patients gave OD values of greater than 0:55 and had DAT titres of 1:1,600. Both tests are sensitive and specific for the diagnosis of VL cases. DAT, being simpler and more economical, will be suitable for diagnosis and epidemiological studies for VL under rural conditions of India.     

Childhood cutaneous polyarteritis nodosa: an unusual presentation

A 6-year-old boy presented with post-burn like cutaneous scars over the buttocks and the back of thighs, following skin ulceration. Cutaneous polyarteritis (CPA) was diagnosed based on the histopathological examination of the skin biopsy specimen from one of the scars. Such a presentation of childhood CPA, to our knowledge, is not documented in the English literature.     

Dexmedetomidine infusion to facilitate opioid detoxification and withdrawal in a patient with chronic opioid abuse

Many patients are admitted to the intensive care unit (ICU) for acute intoxication, serious complication of overdose, or withdrawal symptoms of illicit drugs. An acute withdrawal of drugs with addiction potential is associated with a sympathetic overactivity leading to marked psychomimetic disturbances. Acute intoxication or withdrawal of such drugs is often associated with life-threatening complications which require ICU admission and necessitate prolonged sedative analgesic medications, weaning from which is often complicated by withdrawal and other psychomimetic symptoms. Dexmedetomidine, an alpha-2 (α(2)) agonist, has been used successfully to facilitate withdrawal and detoxification of various drugs and also to control delirium in ICU patients. Herein, we report a case of a chronic opioid abuse (heroin) patient admitted with acute overdose complications leading to a prolonged ICU course requiring sedative-analgesic medication; the drug withdrawal-related symptoms further complicated the weaning process. Dexmedetomidine infusion was successfully used as a sedative-analgesic to control the withdrawal-related psychomimetic symptoms and to facilitate smooth detoxification and weaning from opioid and other sedatives.     

131I activity for remnant ablation in patients with differentiated thyroid cancer: A systematic review

CONTEXT: Radioiodine ablation of the thyroid remnant after thyroidectomy is commonly performed in the management of patients with differentiated thyroid cancer. Although many centers administer an activity of 100 mCi, there is uncertainty over using a lower activity. OBJECTIVE: A systematic review of the published literature was used to compare the success rates of remnant ablation using approximately 30 mCi with approximately 100 mCi (1.1 vs. 3.7 GBq). DATA SOURCES: Data were obtained from MEDLINE and EMBASE for the years 1966 to March 2006. STUDY SELECTION: All studies that reported rates of successful ablation associated with approximately 30 or approximately 100 mCi of radioiodine were reviewed. DATA EXTRACTION: Studies were based on reviews of patient case notes (n = 41), prospective cohorts (n = 12), and randomized trials (n = 6). We obtained the success of thyroid remnant ablation according to different administered activities of radioiodine. Where a study reported on two or more activities, the risk ratio of having a successful ablation (approximately 30 vs. approximately 100 mCi) was calculated and combined in a meta-analysis. DATA SYNTHESIS: Observational studies confirmed the high ablation success rate ( approximately 80%) using approximately 100 mCi, although 22% of studies reported a rate of 90% or greater. The pooled ablation success rate in these studies was 10% lower using 30 mCi compared with 100 mCi (95% confidence interval, 3-17%; P = 0.01). The meta-analysis of the randomized trials produced equivocal results. For example, the rate of successful ablation in patients given 30 mCi was 8% lower compared with 100 mCi (95% confidence interval, 29% lower or up to 20% greater, P = 0.58), consistent with there being no difference or that 30 mCi is much less effective. CONCLUSIONS: From the published data, it is not possible to reliably determine whether ablation success rates using 30 mCi are similar to using 100 mCi. Large randomized trials are needed to resolve the issue and guide clinical practice.