Antioxidant enzymes in Acanthocheilonema viteae and effect of antifilarial agents

Adult worms of Acanthocheilonema viteae were found to be susceptible to the reactive oxygen intermediates (ROI) generated by the xanthine-xanthine oxidase (X-XO) system. The damage caused by this system was completely abolished by superoxide dismutase (SOD) and catalase but not by mannitol. The results, therefore, suggest that superoxide anions (O2-) and hydrogen peroxide (H2O2) alone or in combination might be toxic to the filariid. A. viteae exhibited the presence of an active enzyme system to protect itself against the oxidants. SOD and catalase were present in high levels of activities and appeared to constitute the major defence system. The role of glutathione peroxidase (GPx), on the other hand, seemed less important due to the weak activities of glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PDH). A. viteae also released SOD, catalase and GPx in the ambient medium, which appear useful in protecting the filariid against ROI generated by the host in the immediate surroundings of the parasite. Antifilarial agents, diethylcarbamazine (DEC) and 2,2'-dicarbomethoxylamino-5,5'-dibenzimidazolyl ketone (82/437) appreciably inhibited catalase and GPx of A. viteae. Inhibition of these enzymes appears to render the parasite prone to H2O2 toxicity leading to death. No adverse effect on antioxidant enzymes of liver, lungs and subcutaneous tissue of Mastomys natalensis recorded as a result of exposure to 82/437 suggests a non-toxic nature to the compound.     

Susceptibility of hamsters to caecal amoebiasis by oral infection

A method is described for successfully establishing caecal amoebiasis in hamsters which were not fed and which were pretreated with 1 ml of magnesium sulphate every 24 hours for three days and then given 12 x 10(5) trophozoites of the HM-1 axenic strain or 18 x 10(5) trophozoites of the HK-9 axenic strain of Entamoeba histolytica by the oral route. All the animals developed diarrhoea within 24 hours of infection. When the animals were killed on the fifth day after infection the caecum was swollen and fused. Large macroscopic ulcers full of pus could be seen in the caecum. None of the control animals showed any of the changes mentioned above.     

Fetotoxic response of technical quinalphos in rats.

Technical Quinalphos was administered po to pregnant rats through day 6-20 of gestation at doses of 0.5 or 1.5 mg/kg body weight. Quinalphos produced enzymatic changes in liver and serum of dams associated with mild pathomorphological changes in liver and brain. Fetotoxic effects were not observed at the tested dose levels as determined by total number of implantations, percentage resorption, live fetuses, crown rump length and fetal weight. A few insignificant skeletal deformities were noticed. A significant inhibition of acetylcholinesterase activity in fetal brain and placenta indicated possible transmigration of quinalphos from dams to fetuses.     

Molecular mechanisms of apoptosis in the cells of the immune system in human aging

Summary: Aging is associated with progressive decline in immune functions and increased frequency of infections, autoimmunity, and cancer. Among immune functions, a decline in T‐cell functions during aging predominates. In this review, I discuss the molecular signaling of three distinct pathways of apoptosis, namely the death receptor pathway, the mitochondrial pathway, and the most recently described endoplasmic reticulum stress pathway, and the relative sensitivity of naïve, central memory, and effector memory CD8⁺ T‐cell subsets to apoptosis. In addition, I review apoptosis, especially via death receptor pathway, in naïve and various memory subsets of CD4⁺ and CD8⁺ T cells (with primary emphasis on CD8⁺ naïve and memory subsets) in human aging and discuss the role of apoptosis in immune senescence.     

Lipomeningocoele masquerading as leprous trophic ulcers

Trophic ulcers over both feet in a 24 years old male were initially diagnosed as of leprous etiology. However detailed investigations revealed spina bifida and lipomeningocoele over sacral region. Importance of thorough neurological investigations in such cases is stressed to avoid mis-diagnosis of leprosy.     

Type O renal glucosuria

We observed a 7-year-old boy with virtual absence of renal tubular glucose reabsorption (type O renal glucosuria). Glucose titration studies in his family revealed severe type A renal glucosuria in a younger brother, a mild type A defect in the mother and normal glucose reabsorption in the father; thus a spectrum of renal glucose transport defects was observed in members of the same family.     

CT demonstration of complex dorsal spinal dysraphism.

An unusual case of dorsal spinal dysraphism in a four year old child is presented. Various abnormalities including diastematomyelia, an extradural arachnoid cyst arising from one of the two dural tubes, and lipomeningomyelocele with a related rib-like bony structure were demonstrated with Iohexol CT and subsequently confirmed at surgery.     

Thiazolidinediones and congestive heart failure—exacerbation or new onset of left ventricular dysfunction?

BACKGROUND: Patients with diabetes mellitus have a high incidence of coronary heart disease and congestive heart failure (CHF). Thiazolidinediones (TZD) are a new class of pharmacological agents for the treatment of Type 2 diabetes mellitus, which have many beneficial cardiovascular effects. Peripheral oedema and weight gain have been reported in 4.8% of subjects on TZDs alone, with a higher incidence noted in those receiving combination insulin therapy (up to 15%), but there is limited data on the occurrence of CHF. METHODS AND RESULTS: In this paper, we report on six cases of TZD-induced fluid retention with symptoms and signs of peripheral oedema and/or CHF that occurred in subjects attending our diabetic clinic. The predominant finding in all cases was of diastolic dysfunction. All subjects were obese and hypertensive, with 5/6 having the additional risk factor of LVH, 5/6 subjects had microvascular complications, whilst 3/6 were also on insulin therapy. CONCLUSION: We suggest that obese, hypertensive diabetics may benefit from echocardiographic screening prior to commencement of TZDs, as these agents may exacerbate underlying undiagnosed left ventricular diastolic dysfunction.