Transport studies and enzyme assays in mice infected with human Giardia lamblia

It is well established that Giardia infection causes malabsorption. However, the precise mechanism of such a malabsorption is not known. To investigate this, transport studies, using the tissue accumulation technique, were carried out in mice infected with G. lamblia obtained from human stools. There was a significant fall in the transport of D-glucose, L-alanine and glycine in the infected animals compared with the controls. Kinetics of the D-glucose and glycine transport system were examined by measuring the tissue uptake in the presence of different concentrations of the substrate. For glucose, the affinity constant (Km) for the transport site was the same (4 . 37mM) in normal and infected animals but the maximal transport rate (V max) was considerably reduced in infected animals (158 . 7 mu moles/hr/g tissue) compared with (357 . 1 microgram moles/hr/g tissue) in controls. Results with glycine were similar; the Km was similar in control and infected animals (5 . 7 mM) whereas the V max was reduced in infected animals (27 . 02 microgram moles/hr/g tissue) compared with controls (45 . 5 micrograms moles/hr/g tissue). Analysis of the intestinal enzymes showed a significant decrease in the levels of brush border sucrase, lactase and alkaline phosphatase in infected animals; the cellular enzymes, LDH, GOT and GPT remained unaffected. The observed aberrations in the transport functions and brush border enzymes suggest that G. lamblia causes malabsorption by damaging the epithelial membrane of the enterocyte.

Hemostatic abnormalities following Echis carinatus (saw-scaled viper) envenomation in the rhesus monkey

Hemostatic abnormalities following lethal and sublethal doses of Echis carinatus venom were studied in a subhuman primate model. The observations suggest the occurrence of disseminated intravascular coagulation of varying magnitude within a few hours of envenomation. A procoagulant effect of the venom of Echis carinatus is likely to be the major cause of the disturbance in the hemostatic mechanism.

Myco. leprae infection in normal, thymectomised irradiated and thymus transplanted mice

Normal mice and thymectomised, X-irradiated and thymic transplanted groups of mice were challenged with 10(3) Myco. leprae in the foot pad. Course of infection was studied for a period of seven months by sacrificing animals every month and counting the bacilli from the pooled tissues. In the thymectomised irradiated group the counts showed a plateau from 5th month onwards, whereas in control and thymus implant group the counts rose in 6th and 7th months.

Kinetics of lymphocyte subpopulations and their functions in cases of amoebic liver abscess

This study shows the relationship between lymphocyte subpopulations and their response to non-specific stimulant phytohaemagglutinin (PHA) and specific stimulant (amoebic antigen) in cases of amoebic liver abscess in relation to the duration of disease, based on the first appearance of symptoms and/or signs, 26 patients with amoebic liver abscess and 20 normal, healthy controls were studied. Five of the patients gave a history of alcohol intake for the last 10 to 15 years. Eight had a solitary abscess and five had multiple abscesses, as seen on liver scan. No change in the B cell count was noticed in any of the patients. Depression of the T cell number and function was noticed from two weeks onwards. A history of alcohol intake made no difference. Cases with multiple liver abscesses were more immunologically depressed than were those with a solitary abscess.

BCG induced immunity to Mycobacterium leprae in mice

One to three BCG vaccinations were given to various groups of mice--25 to 2 days preceding challenge with Myco. leprae. Harvesting of Myco. leprae was done every month upto a period of 7 months. Lymph node enlargement was taken as an indicator of successful vaccination. An increasing degree of protection was noted in BCG immunised mice as observed by a reduced number of bacilli harvested. Protection afforded was proportional to the number of doses of BCG given.

Assessment of diluted Dharmendra lepromin

Twenty-one patients of lepromatous and tuberculoid type were tested with standard, 1:2 and 1:4 diluted Dharmendra lepromin. It was found that correlation exists between the degree of induration and the number of bacilli in the lepromin. Uniform and reproducible results were obtained with Dharmendra antigen containing 40 million bacilli/ml. This is of special significance in enhancing the present meagre supplies of lepromin.

Cutaneous responses to antigens and irritants in patients of leprosy

Forty seven patients of various types of leprosy were skin tested with PPD, Dharmendra lepromin, DNCB, Coccidiodin, histamine and croton oil. Twenty five age matched normal controls were also included in the study. All types of leprosy patients reacted in smaller numbers and with decreased response to all antigens and irritants as compared to normal controls. Depression of response being minimum in tuberculoid and maximum in lepromatous group. None of the patients or controls reacted to coccidiodin. Details are given.

Serum lipids in leprosy

Sera of 58 patients of various types of leprosy were tested for total fat, phospholipids, cholesterol and alpha and beta lipoproteins. Total fat and both fractions of lipoproteins were found to have values comparable to normals in all types of leprosy. Serum phospholipid levels were significantly reduced in LL type of leprosy as compared to normals and TT group of patients. Similarly cholesterol levels were found to have significantly no value in LL group compared to that of the controls.

Amoebic antigen in immunodiagnosis and prognosis of amoebic liver abscess

The detection of amoebic antigen by counterimmunoelectrophoresis is very useful and important in the immunodiagnosis of invasive hepatic amoebiasis. The antigen was demonstrated in 115 (92%) of 125 patients with amoebic liver abscess. All the 19 cases which showed Entamoeba histolytica in the 'pus' were positive for the antigen and 96 of 106 samples negative for the parasite by smear and culture were also positive for the antigen. In none of the controls was a falsepositive reaction obtained. 12 of 13 liver biopsy specimens were also positive for antigen. The persistence or disappearance of the antigen from the liver pus biopsy specimens was investigated: the antigen disappeared in eight of the 33 cases followed for intervals up to 60 days after cure, suggesting that this is also an important additional criterion for evaluating the prognosis of the disease. Further, it has been shown that amoebic infection is followed by the appearance of specific antigen or antigenic substances in the serum which were demonstrated in 23 of 89 proved cases of amoebic liver abscess cases. Its possible role in immune complex formation and the pathogenesis of the disease is discussed.