Effect of a single oral dose of ddt on lipid metabolism in rat

A single oral dose of 1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane (DDT) (600 $\text{mg}\text{kg}$ body weight) was given to rats and the levels of various lipids in adipose tissue, liver and plasma were studied. No alteration was observed in the levels of various lipid classes in these tissues except for a decrease in the phospholipid and triglyceride fractions of liver. Lipoprotein lipase activity of post-heparin plasma (protamine-sensitive and -resistant) was significantly decreased, whereas in liver and adipose tissue, the activity of this enzyme remained unchanged.     

Lectin-binding characteristics of Wuchereria bancrofti microfilariae

The binding of 10 different lectins to the surface of microfilariae of Wuchereria bancrofti has been investigated. Wheat germ agglutinin (WGA) and Helix pomatia lectin (HPA) bound specifically to the sheathed microfilariae indicating the presence of N-acetyl-D-glucosamine and N-acetyl-D-galactosamine respectively on the surface. Exsheathed microfilariae did not react with any of the lectins. Treatment of sheathed microfilariae with proteases resulted in increased binding of WGA and HPA. Such treated microfilariae showed a weak binding of Concanavalin A (Con A), and lectins of lentil (LCH) and of Limulus polyphemus (LPA). Sheathed microfilariae incubated with sera of people living in endemic zones of filariasis but with no apparent evidence of infection (endemic normals), or with sera of chronic elephantiasis patients, or with their respective gamma globulin fractions, bound Con A and LCH. These lectins bound weakly to exsheathed microfilariae under the same conditions. Binding was due to the mannose components of the specific immunoglobulins of the sera which coated the microfilariae. However, microfilariae when incubated with sera or their globulin fractions from non-endemic normals (NEN), or from microfilarial carriers, did not bind Con A and LCH, suggesting that specific immunoglobulins were neither present in NEN sera nor in significant amounts in sera of microfilarial carriers.     

Brugia malayi: serum dependent cell-mediated reactions to microfilariae

Sheathed and exsheathed microfilariae of Brugia malayi are killed by normal rat cells in the presence of immune serum in vitro. Immune serum heated at 56 degrees C for 1 hour lost this activity which was largely restored by the addition of fresh normal rat serum. EDTA but not EGTA abolished this activity indicating the operation of complement by alternate pathway. Fresh normal rat serum alone promoted cellular adherence without exerting cytotoxicity to the microfilariae. The activity in the immune serum could be removed with Staphylococcus aureus cells containing Protein A or anti-IgG antiserum. The activity could also be absorbed to and eluted from Protein A--sepharose CL-4B suggesting the involvement of IgG. Neutrophils and macrophages participate in the antibody dependent cell-mediated cytotoxicity phenomenon. Eosinophils while adhering to the microfilariae exert cytotoxicity only to the exsheathed parasites.     

Pharmacokinetics of primaquine in patients withP. Vivax malaria

Summary The pharmacokinetics of primaquine (PQ) and its major carboxylic acid metabolite (PQC) have been studied in seven Indian patients withP. vivax malaria following PQ 15 mg/day p.o. for 14 days. After a single oral dose on Day 1, a mean peak blood concentration of 50.7 ng/ml PQ was attained after 2.3 h, which declined monoexponentially with a half-life of 5.6 h. The mean total body clearance was 37.6 l/h and the volume of distribution was 2921. The mean renal excretion (0–24 h) of the drug was only 0.54% of the dose and renal clearance was 0.189 l/h. Following chronic administration, none of the pharmacokinetic parameters was affected, and a steady state blood concentration of 2.5–4.2 ng/ml PQ was attained. After the first dose of PQ, PQC had a mean area under the blood concentration — time curve 11-fold higher than that of the parent drug. In contrast to the rapid distribution and elimination of PQ, the metabolite showed a longer mean residence time and accumulation in the body. The mean C_max and AUC of the metabolite on Day 14 were 48 and 40% higher than the corresponding Day 1 values. The metabolite could not be detected in urine at any time in any patient. PQ and its metabolite did not show any accumulation in blood cells.Communication No.797 from Hindustan CIBA-GEIGY Limited, Research Centre