Biomedical subjects

C Vaishnavi

Publications and source records attributed to C Vaishnavi.

At least 19 recordsLinked to original sources

PubMed1993

Bioaccumulative potential and toxicity of endosulfan insecticide to non-target animals.

1. Endosulfan insecticide is a polychlorinated compound used for controlling a variety of insects; it is practically water-insoluble, but readily adheres to clay particles and persists in soil and water for several years. Its mode of action involves repetitive nerve-discharges positively correlated to increase in temperature. This compound is extremely toxic to most fish and can cause massive mortalities. In fish, it causes marked changes in Na and K concentrations, decrease in blood Ca(2+) and Mg levels and inhibits Na, K and Mg-dependent ATPase (in brain). 2. Bioaccumulation of endosulfan is reported for marine animals; however, freshwater animals (e.g., crayfish) accumulate it to some extent, but they lose the compound rapidly during depuration. Endosulfan is generally less toxic to aquatic invertebrates than fish. However, it causes decreases in adenylate energy charge, oxygen consumption, hemolymph amino acids, succinate dehydrogenase, heart-beat (mussel) and altered osmoregulation. 3. Generally, mammals are less susceptible to endosulfan's toxicity than aquatic animals. The majority of studies conducted on laboratory mammals can be summarized. (a) Neurotoxicity: male rats are more sensitive than females to endosulfan, which decreases brain and plasma acetylcholinesterase activity. Endosulfan I (a metabolite) causes a significant change in norepinephrine, 5-HT and GABA. (b) Renal toxicity: inhibition of MFOs activity was noticed in rats; other effects included changes in proximal convoluted tubules and necrosis of the tubular epithelium. (c) Hepatotoxicity: chemically-induced aminopyrine N-demethylase and aniline hydrolase were found in rat liver, and reduction in the glycogen level occurred. (d) Hematologic toxicity: endosulfan exposure resulted in a significant decrease in the level occurred. (d) Hematologic toxicity: endosulfan exposure resulted in a significant decrease in the erythrocyte glutathione reductase, hemoglobin amount, RBC number and mean corpuscular volume. 4. Respiratory toxicity: involved dyspnea, acute emphysema, cyanosis and hemorrhages in teh interalveolar portions of rat's lungs. 5. Biochemical: in rats, endosulfan caused increased glucose-6-phosphate dehydrogenase activity, blood glucose level, phospholipid contents of the microsomal and surfactant system, and profoundly induced the activity of alcohol dehydrogenase and cytosolic glutathione S-transferases. It also decreased significantly Na+, K+ and Mg(2+) ATPases, plasma calcium level and alkaline phosphatase in the intestinal epithelium. 6. Immunologic toxicity: rat serum antibody titer to tetanus toxin, IgG, IgM and gammaglobulins were significantly reduced. 7. Reproductive toxicity: degenerative changes in the seminiferous epithelium, induction of the rate-limiting enzyme in testosterone production (3beta-hydroxysteroid transferase and 17 beta-hydroxysteroid transferase), histological changes in reproductive organs, testicular atrophy and the occurrence of ovarian cysts were noticed in rat. Reduction in the weight of secondary sex organ was also observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1993

Suppression of ADCC by immune complexes formed in vitro in Mycobacterium leprae-infected mice.

Antibody-dependent cellular cytotoxicity (ADCC) was assessed in mice infected experimentally with Mycobacterium leprae and injected simultaneously with in vitro-formed immune complexes (IC). Significant decrease in the ADCC function was observed in animals given IC at zero day (0dIC) and 3 months (3mIC) post inoculation with M. leprae, when ADCC activity was assessed at 3, 6 and 9 months period. From the data obtained we believe that ADCC is suppressed by IC formed in vitro.

Animals↗

PubMed1992

Detection of a Mycobacterium leprae cell wall antigen in the urine of untreated and treated patients.

A total of 90 leprosy patients, 12 household contacts and 10 normal subjects were studied for the detection of Mycobacterium leprae cell wall antigen in urine using monoclonal antibody (ML30A2 IgG). In untreated multibacillary leprosy (BL-LL) the M. leprae cell wall antigen could be demonstrated in the urine of 14 (64%) patients by immunofluorescence (IF) and 22 (100%) by ELISA. In untreated paucibacillary leprosy (TT-BT), it could be demonstrated in 3 (11.5%) and in 13 (50%) patients by IF and ELISA methods respectively. All but 1 household contact (later confirmed to have BL leprosy) and all 10 normal subjects' urine was negative for M. leprae cell wall antigen by both methods. The same antigen was, however, demonstrated in urine of 50% paucibacillary patients who had received 6 months of treatment and in 68% multibacillary patients who had received 24 months of WHO recommended multidrug therapy. M. leprae cell wall antigen assays in urine will not be useful in the follow-up of leprosy patients on multidrug therapy.

Adolescent↗

PubMed1992

C-reactive proteins, immunoglobulin profile and mycobacterial antigens in cerebrospinal fluid of patients with pyogenic and tuberculous meningitis.

Cerebrospinal fluid (CSF) samples were collected from 12 patients with pyogenic meningitis (PM), 19 with tuberculous meningitis (TBM), 20 with clinically suspected but not definitely proved cases of tuberculous meningitis (STBM) and 12 normal controls. C-reactive proteins, immunoglobulins G, A, M and mycobacterial antigens were estimated in the CSF samples. Seven out of 51 (13.7%) samples obtained from the patient groups were positive for CRP. Immunoglobulins M and A were significantly raised in the PM group. When the TBM and STBM groups were compared with the controls a highly significant increase was obtained for all immunoglobulins. Mycobacterial antigens/epitopes were identified in 36.8% samples with TBAGB1 and TB68-H monoclonals and in 26.3% with WTB72-A2. In case of patients with suspected TBM, 6.6% were positive with TBAGB1 and WTB72-A2 and 13.3% with TB68-H. However, non-tuberculous patients also reacted with WTB72-A2 (10.5%) and TB68-H (21.0%). This is, to the authors' knowledge, the first report on the presence of CRP in the CSF. Technique for immunoglobulins in CSF is also updated in this paper. We infer that the monoclonal antibody TBAGB1 and immunoglobulins G and A may be safely considered as diagnostic markers of TBM. Estimation of CRP in CSF samples may be made to give a preliminary or additional diagnosis of meningitis regardless of its aetiology.

Antigens, Bacterial↗

PubMed1992

Hydrolytic enzymes in leprosy sera.

Serum samples collected from 45 untreated leprosy patients and 10 healthy subjects were studied for the activities of alkaline phosphatase, N-acetyl beta-glucosaminidase and beta-glucuronidase. A highly significant increase in the specific activity of these enzymes was observed in all types of leprosy patients as compared to controls. Increase in the level of circulatory hydrolytic enzymes could be a tissue damaging factor and may be responsible for many of the lesions seen in leprosy.

Acetylglucosaminidase↗

PubMed1992

Release of acid hydrolases in spectrum of human leprosy.

Release of acid hydrolases by blood monocytes (BM) of leprosy patients both before and after 6 months of chemotherapy was measured fluorimetrically. Monocyte cultures were set up for spontaneous as well as zymosan dependent enzyme release measured after 2 hrs and 24 hrs of culture. In the untreated multibacillary group (BL/LL) a significantly higher (P < 0.001) release of both B-glucuronidase (BG) and N-acetyl glucosaminidase (NAG) was observed compared to the paucibacillary group (BT/TT) and healthy controls. On comparing the BT/TT group with controls a significant decrease (P < 0.001) in zymosan dependent NAG release was observed in the former group at 2 hrs culture. After 6 months of antileprosy therapy, a significant decrease (P < 0.05) in BG release was observed from BM of multibacillary patients, whereas NAG activity increased significantly (P < 0.05) in the paucibacillary group compared to the controls. The results of the present study suggest that non-oxidative metabolic status of BM vary within the leprosy spectrum.

Acetylglucosaminidase↗

PubMed1992

Adenosine triphosphate content of Mycobacterium leprae by percoll buoyant density centrifugation.

Thirty nine untreated patients of bacilliferous leprosy with a mean bacteriological index of 4.8 and morphological index of 1.3% formed the study group. Adenosine triphosphate assay was carried out by (i) enzyme treatment method in 18 patients and (ii) percoll buoyant density gradient method in 21 patients. ATP content obtained by percoll buoyant density gradient method was significantly higher than that obtained by enzyme treatment method. Percoll buoyant density centrifugation for purification and isolation of bacilli from human leproma is simplier, quicker and can serve as an alternate method of enzyme treatment.

Adenosine Triphosphate↗

PubMed1992

Field utility of phenolic glycolipid coated latex agglutination test for rapid detection of bacilliferous leprosy cases.

Serum samples were collected from eighty-three leprosy patients and twenty-five healthy controls supposedly not exposed to Mycobacterium leprae infection. Phenolic glycolipid-1 coated latex agglutination test (PGL-LAT) was carried out with the serum samples to detect antibodies specific to M. leprae. Samples showing positive agglutination were 50% in the lepromatous leprosy (LL) group showing no erythema nodosum leprosum (ENL) complications, 66.6% in LL group with ENL complication, 60% in borderline lepromatous (BL) group, 50% in borderline (BB) and 33.3% in borderline tuberculoid (BT). The patients belonging to the tuberculoid (TT) group and most of the long-term treated patients were interestingly negative, and so were sera from all the healthy controls. PGL-LAT developed by us therefore is specific and a fairly sensitive technique to detect antibodies specific to M. leprae and will be very useful in field conditions.

Agglutination Tests↗

PubMed1992

Respiratory burst metabolic status of macrophages in experimental leprosy.

Peritoneal macrophages from uninfected controls and Mycobacterium leprae infected Swiss albino mice were studied for their respiratory burst (RB) activity at different time intervals. The RB metabolic activity of macrophages declined significantly after 3 month infection using latex (p less than 0.001) and M. leprae (p less than 0.01) as stimuli. However, significant rise (p less than 0.001) in the oxidative metabolic activity was seen at 6 and 9 months postinfection period on stimulation with both the stimuli. The sharp rise in the oxidative metabolic status at peak period of infection in the experimental animals suggests that the macrophages are functionally normal though M. leprae is unable to trigger the respiratory burst sufficiently.

Animals↗

PubMed1991

Acute phase reactants in leprosy.

Serum levels of C-reactive protein (CRP) and plasma levels of fibronectin (Fn) were studied in 74 untreated leprosy patients. CRP was detected by latex agglutination in 25.6% of the patients. A significant increase in Fn levels was seen in all the groups of leprosy patients, as compared to the controls.

Acute-Phase Proteins↗

PubMed1991

Epidermal calmodulin levels in psoriasis before & after therapy.

Epidermal calmodulin (CaM) levels were measured in the involved and uninvolved skin in 26 psoriasis patients before and after treatment either with dithranol topically or methotrexate orally. The mean epidermal calmodulin levels (+/- SD) in the involved and uninvolved psoriatic skin before treatment were 21.99 +/- 10.22 and 11.97 +/- 3.50 in the patients to be treated with short contact dithranol therapy (SCDT) while it was 19.46 +/- 8.13 and 11.27 +/- 7.23 in the patients to be treated with systemic methotrexate. Clearance of psoriatic lesions was associated with a significant fall (P less than 0.05) in epidermal calmodulin, activity irrespective of the treatment modality used. Also, there was a significant reduction (P less than 0.05) in the calmodulin levels in the epidermis of uninvolved skin following successful treatment.

Adolescent↗

PubMed1990

Renal brushborder membrane vesicle. Study of marker enzymes and uptake of nutrients in Mycobacterium leprae infected mice.

The renal brush border membrane vesicles (BBMV) were used to elucidate the early biochemical functional status during the course of experimental M. leprae infection in mice. The activities of the characteristic brush-border enzymes viz: alkaline phosphatase, leucine amino peptidase and gamma-glutamyl transpeptidase were found to be significantly decreased (p less than 0.001) at 3 and 6 months after infection. The transport of nutrients viz: D-glucose, L-alanine, L-lysine and L-aspartate across BBMV showed similar pattern. The activity of brush border enzymes and transport of nutrients across the membrane returned to normal at 9 months post-infection suggesting regeneration of the brush border membrane.

Alkaline Phosphatase↗

PubMed1989

Rothmund-Thomson syndrome in two siblings.

Rothmund-Thomson syndrome, a rare autosomal recessive disorder, is characterized by photosensitivity; specific skin changes including poikiloderma, atrophy, and telangiectases; juvenile cataracts; short stature; and bone defects. We describe two siblings with this syndrome.

Bone Diseases, Developmental↗

PubMed1989

Bacillaemia in leprosy and effect of multidrug therapy.

Twenty-five patients of bacilliferous leprosy (17 LL, 8 BL) were studied by the modified haemolysis method for occurrence of bacillaemia and its clearance after two multidrug therapy regimens. Acid-fast bacilli were found in 76% of all patients and in 88.2% LL and 50% BL patients. Bacillaemia occurred with significantly reduced frequency in patients with type II reaction. Acid-fast bacilli were demonstrable in peripheral blood after 1 month in one patient on MDT of an Indian Working Group and 3 lepromatous patients on WHO multidrug therapy. However, bacillaemia could not be demonstrated in any patients after 2 and 3 months of treatment with both regimens.

Adolescent↗

PubMed1989

Effect of suppressor cells on antibody producing cells in mice infected with Mycobacterium leprae.

Swiss albino mice were transfused with suppressor cells obtained after in vivo stimulation of mice with Con A (NS group). Some of the animals were infected with Mycobacterium leprae (NSI-group). Half of these animals were treated with dapsone (NSIT group). Adequate normal (NC) and infected (NI) controls were included. A plaque assay was carried out at different time periods to elucidate the effect of suppressor cells on antibody producing cells. No significant difference was seen in the number of plaque forming cells (PFC) in infected and dapsone treated animals (NSIT) when these were compared with controls. However significant increase seen in the number of IgM plaque forming cells at 6 months in NI and NSI groups and IgG PFC in NI group could be due to the peak footpad infection during this period. The significant decrease in the number of IgG PFC in NS and NSIT group compared to NC at 0 month is probably due to the suppressor cell activity in these groups.

Animals↗

PubMed1989

Urinary excretion of renal brush-border enzymes in lepromatous leprosy--a preliminary investigation.

Activities of the brush-border enzymes, alkaline phosphatase, maltase, leucine aminopeptidase, and gamma-glutamyl transpeptidase, were measured in urine samples of 25 lepromatous leprosy patients and an equal number of age-matched healthy controls. None of the patients were shown to be suffering from any other systematic disease. The enzymatic activities were shown to be significantly elevated in leprosy patients when compared to controls.

Alkaline Phosphatase↗

PubMed1989

Primary dapsone resistance as assessed by uptake of labelled thymidine by the macrophage resident Mycobacterium leprae.

12 untreated lepromatous leprosy patients were screened for primary dapsone resistance by the uptake of labelled thymidine by macrophage resident M. leprae. There were found to harbour primary dapsone resistant strains of M. leprae and another three partially resistant strains to the drug. This rapid, simple and reliable method should be used routinely to screen leprosy patients, for drug resistance.

Cells, Cultured↗

PubMed1989

Leprosy and hepatitis B surface antigen.

An ELISA technique has been developed to detect HBsAg in the sera of leprosy patients. Out of ninety-two serum samples taken from untreated leprosy patients, 10 samples were positive for HBsAg. The ELISA used in the present investigation is a low cost, reliable and sensitive marker of HBsAg. It is better than lesser sensitive (haemagglutination and counterimmunoelectrophoresis), costly and hazardous (radioimmunoassay) techniques and is therefore recommended for routine use.

Enzyme-Linked Immunosorbent Assay↗