Effects of Selected Therapeutic Agents on Urolithiasis Induced by Terephthalic Acid in the Male Weanling Fischer 344 Rat

Effects of Selected Therapeutic Agents on Urolithiasis Inducedby Terephthalic Acid in the Male Weanling Fischer 344 Rat. Wolkowski-Tyl,R. and Chin, T.Y. (1983).Fundam. Appl. Toxicol. 3:552–558.Exposure of male weanling Fischer 344 rats to 4.0% terephthalicacid (TPA) in the diet (positive controls) for two weeks (postnataldays 28–42) resulted in a 50% incidence of bladder calculi,aciduria, elevated urinary excretion of calcium (Ca) and magnesium(Mg), and slightly elevated serum levels of Ca and Mg relativeto negative controls. Possible mechanisms of TPA-induced urolithiasiswere examined by daily oral administration of allopurinol, chlorothiazide,or neutral phosphates, at their recommended therapeutic dosesduring exposure to dietary 4.0% TPA. An additional group wasfed 4.0% TPA and 4.0% sodium bicarbonate in the diet for twoweeks. Chlorothiazide or dietary bicarbonate abolished TPA-inducedurolithiasis, but allopurinol and neutral phosphates had noeffect. Bicarbonate increased water intake above that of positivecontrols and ameliorated the TPA-induced aciduria. It also increasedurinary Mg and TPA above positive control values. Chlorothiazidereduced urinary Ca and TPA levels below those of positive controls.Treatment with chlorothiazide, neutral phosphates or bicarbonateslightly reduced serum Ca below the levels in either positiveor negative controls. Drug treatment did not alter TPA-inducedelevated serum Mg levels, but bicarbonate reduced serum Mg levelsto negative control values. In conclusion, TPA-induced urolithiasisin male weanling rats was abolished by therapeutic agents whichreduced urinary Ca and TPA excretion (chlorothiazide), or whichenhanced water intake, urinary Mg and TPA excretion, and amelioratedTPA-induced aciduria (dietary bicarbonate). These factors appearto be critical for TPA-induced urolithiasis.     

Enhanced Effectiveness of Dimethyl-4,4‘-dimethoxy-5,6,5’,6‘-dimethylene dioxybiphenyl-2,2’-dicarboxylate in Combination with Garlic Oil against Experimental Hepatic Injury in Rats and Mice

The present study was designed to evaluate the effects of dimethyl-4,4′-dimethoxy-5,6,5′,6′-dimethylene dioxybiphenyl-2,2′-dicarboxylate (PMC) in combination with garlic oil against chemical-induced hepatic injury in rats and mice. Rats insulted with carbon tetrachloride were concomitantly treated with PMC and/or garlic oil (50 and 100 mg kg^?1, respectively) for four weeks. Whereas treatment of animals with garlic oil alone was ineffective in suppressing carbon tetrachloride-induced hepatotoxicity, administration of PMC in combination with garlic oil more effectively protected the liver against the carbon tetrachloride-induced insult than PMC alone, as monitored by serum aminotransferase activity. Hepatoprotective effects of the formulation were further supported by the changes in the numbers of Kupffer cells and dead hepatocytes. Although prior treatment of rats with PMC for three days failed to protect hepatotoxicity elicited by allyl alcohol, the formulation of PMC and garlic oil was capable of blocking allyl alcohol-induced hepatotoxicity by ～ 40%. To further examine the effect of the agents on lipid metabolism in the liver, hepatic triglycerides and cholesterol contents were assessed in mice after a diet containing PMC and/or garlic oil for one week followed by a single dose of carbon tetrachloride. Garlic oil appeared to be more effective in bringing hepatic lipid levels to those of control than PMC alone. Treatment of animals with PMC in combination with garlic oil synergistically improved chemical-induced impairment of hepatic triglycerides and cholesterol. These results demonstrated that PMC in combination with garlic oil is effective in protecting (or treating) chemical-induced hepatic injury and that the formulation may be effective against chemical-induced fat-infiltration of the liver.     

The Effect of Radiofrequency Catheter Ablation on Permanent Pacemakers: An Experimental Study

Radiofrequency current is being investigated as an alternative to direct current shock for transcatheter ablation of cardiac arrhythmias. Permanent pacemakers are known to be susceptible to high frequency electromagnetic interference. This study was performed to examine the effects of transcatheter radiofrequency ablation on permanent pacemakers in a worst-case scenario. Nineteen pulse generators representing 16 models from seven manufacturers were acutely implanted in 12 dogs to assess their function during and after ablation. Pulse generators were implanted subcutaneously in the neck and connected to a transvenous permanent pacing lead positioned in the right ventricular apex. A 6F quadripolar electrode catheter was positioned approximately 1 cm from the tip of the permanent pacing lead. Radiofrequency current from an electrosurgical unit was applied between the distal electrode of the catheter and a large diameter skin electrode placed below the left scapula. Three additional ablation sessions were performed with the catheter situated 4-5 cm from the permanent pacing lead. Each ablation consisted of 15 W of radiofrequency power, delivered for up to 30 seconds. Twelve pulse generators were falsely inhibited during radiofrequency ablation while programmed to the VVI or DDD mode, nine of which continued to be inhibited while programmed to the VOO or DOO mode. Five pulse generators paced at abnormal rates, including three examples of one pulse generator model that displayed pacemaker runaway. Runaway was observed during eight ablations, resulting in two episodes of ventricular fibrillation. Eleven pulse generators reverted to noise mode behavior during ablation. Only three pulse generators were unaffected during ablation. No reprogramming or pacing system malfunctions were observed after cessation of radiofrequency current application or during ablations greater than 4 cm from the permanent lead.(ABSTRACT TRUNCATED AT 250 WORDS)     

Extramammary Paget''s disease of the vulva subclinically extending to the bladder neck: Correct staging obtained with endoscopic urethral biopsy

We report a 65-year-old woman with extramammary Paget's disease which recurred on the skin flap. We performed a mapping-biopsy of the urethra by ureteroscopy to select the appropriate treatment. This method is presumed to be useful for determining the margin, deciding the correct staging for extramammary Paget's disease and for making a judgement on appropriate therapy.     

ROLES OF IFN-γ ON STAGE CONVERSION OF AN OBLIGATE INTRACELLULAR PROTOZOAN PARASITE,Toxoplasma Gondii

IFN-γ downregulates the stage conversion of Toxoplasma gondii (T. gondii), from bradyzoites to tachyzoites, and the expression of heat shock protein 70 (HSP70) of T. gondii ( T.g. HSP70) by tachyzoites. T.g. HSP70 has been shown to downregulate NO release from macrophages and also to induce auto-HSP70 antibody formation and IL-10 secretion by VH11-JH1 B-1 cells, resulting in the suppression of host defense responses to T. gondii infection. A novel category of virulent tachyzoite stage of T. gondii expressing T.g. HSP70 (virulent tachyzoite), which indirectly manifests its pathogenicity by downregulating host defense responses, has been proposed.     

A NOTE ON WHITE BLOOD CELL COUNTS IN WHOOPING COUGH

The presence of leucocytosis and lymphocytosis in the blood in pertussis has been well knoxvn since the early report of Frohlich in 1897 (1). Subsequent observations of Meunier (2), Cabot (3), Churchill (4), Crombie (5), Barach (6) and others showed that the increase in the total number of leucocytes occurred almost universally and elevation of the percentage of the lymphocytes occurred in from 80 t0 90 percent of the cases. These authors considered these hematological findings to be of great diagnostic value, especially during the early stage of the disease. However, recent studies of Sauer and Hambrecht (7) and that of Dolgopol (8) demonstrated that such a characteristic blood picture usually occurred only when the clinical symptoms of the disease have well developecl. Nevertheless, there remains the undeniable value of the blood picture in the diagnosis of the disease, as when the patients are brought to the hospital for treatment, they are mostly in the late catarral or early paroxysmal stage and the leucocytosis and the lym phocytosis of the blood :may serve as confirmatory evidences for the clinical diagnosis.     

Postchemotherapy retroperitoneal residual mass in infantile yolk sac tumor

BACKGROUND: Persistent postchemotherapy retroperitoneal residual mass with normalization of alpha-fetoprotein (AFP) in infantile yolk sac tumor is rare. METHODS/RESULTS: A 38-month-old boy with recurrent yolk sac tumor was treated with cisplatin-based combination chemotherapy. After chemotherapy, the retroperitoneal lymph node metastasis, 7 x 6 cm in size, decreased to 2 x 2 cm. Serum AFP levels returned to normal. The retroperitoneal residual mass was resected and histologically showed complete necrosis without viable cancer cells. CONCLUSION: The patient has remained free of disease for 36 months after operation.