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L K Bhutani

Publications and source records attributed to L K Bhutani.

At least 19 recordsLinked to original sources
PubMed1991

Enzyme immunoassay of phagocytosis stimulating tetrapeptide "tuftsin" in normal and leprosy sera.

The serum concentrations of the phagocytosis stimulating the tetrapeptide, tuftsin, were determined by competitive enzyme immunoassay in borderline tuberculoid/tuberculoid (BT/TT, 16 cases), borderline lepromatous/lepromatous (BL/LL, 16 cases), and in healthy controls (20 cases). Using checkerboard titration, 10 ng/well of diphtheria toxoid-p-aminophenylacetyl tuftsin (DTPT) conjugate when incubated with tuftsin antisera at 1:15,000 dilution with a preincubation time of 60 min with the competitor (tuftsin) followed by a further 60-min incubation onto the DTPT-coated wells gave consistent results with a sensitivity of 5 ng/well tuftsin. The mean serum tuftsin concentration was significantly lower in BL/LL patients (134.42 +/- 48.7 ng/ml, p less than 0.01) than in healthy controls (262.86 +/- 59.8 ng/ml), while BT/TT sera (210.94 +/- 75.5 ng/ml) showed slightly decreased levels than did normals, which was not statistically significant. The mean serum IgG levels in BL/LL and BT/TT patients (37.26 +/- 10.99 mg/ml; 28.08 +/- 6.57 mg/ml, respectively) showed significantly (p less than 0.001) higher concentrations than did healthy controls (12.3 +/- 3.6 mg/ml). These observations on the serum concentrations of tuftsin and IgG in leprosy individuals suggest that there is splenic dysfunction in BL/LL patients in terms of the processing of leukokinin to release the free, active molecule tuftsin.

Binding, Competitive↗
PubMed1990

Modulation of human lepromatous monocyte-macrophage functions in vitro by tuftsin.

Human peripheral blood monocytes/macrophages derived from normal donors, patients of tuberculoid leprosy (BT/TT) and lepromatous leprosy (BL/LL) were assayed for stimulated phagocytic responses to the potent macrophage stimulator "Tuftsin" (NH2-Thr-Lys-Pro-Arg-OH) after varying periods (6 h to 14 days) of culture in vitro. The assays consisted of visual scoring of ingested Mycobacterium leprae and radiometric measurement of ingested 14C-acetate labelled Staphylococcus aureus and Mycobacterium tuberculosis (H37Ra). While normal and BT/TT macrophages showed a progressively increasing ability for tuftsin-stimulated phagocytosis with increasing age of culture in vitro, BL/LL macrophages showed the opposite response so that 14-day cultures were refractory to a stimulatory dose of up to 7.0 microM (10 to 20 times the optimal dose for normal and BT/TT macrophages). The 14-day BL/LL macrophage cultures were, however, responsive to 35 microM tuftsin (100 times the optimal dose for normal macrophages). Analysis of the dose-response curves also indicates that BT/TT cultures despite exhibiting an apparent similarity to normal macrophages demonstrate a rightward shift for a maximal stimulated phagocytosis. Finally SEM photo-micrographs of 14-day macrophage cultures of the three groups revealed that while normal and BT/TT cultures demonstrated an increase in membrane ruffling and filopodia on stimulation with 0.8 microM tuftsin, BL/LL cultures exhibited none of the features associated with stimulation. From the above findings, we conclude that lepromatous macrophages may display an aberrant differentiation profile leading to a terminal state of unresponsiveness and that the defect may possibly lie at the level of tuftsin receptor expression or transmembrane signal transduction.

Amino Acid Sequence↗
PubMed1990

Effect of tuftsin stimulation on the microbicidal activity exerted by blood monocyte-macrophages of leprosy patients.

The ability of blood monocyte/macrophages from normal donors, tuberculoid leprosy (BT/TT) and lepromatous leprosy (BL/LL) patients to exert enhanced microbicidal activity was assayed after stimulating with 0.8 microM tuftsin, as a function of the duration of cultures in vitro. Normal and BT/TT macrophage cultures showed a statistically significant increase in microbicidal activity against Staphylococcus aureus at all ages of culture (6 h to 14 days), though the overall magnitude of the enhancement shows a decrease with increasing culture age in the same populations. However, 14-day old BL/LL macrophage cultures were unable to undergo tuftsin-mediated stimulation of microbicidal activity against S. aureus and even, fresh 6 h-old cultures exhibited a tuftsin-stimulated response profile similar to 14-day old normal and BT/TT cultures. Also, 7 and 14-day cultures of normal, BT/TT and BL/LL macrophages were unable to inhibit/kill intracellular Mycobacterium leprae after a single stimulation with 0.8 microM tuftsin. However, serial, daily stimulation with 0.8 microM tuftsin resulted in 77-140% inhibition of 3H-thymidine uptake by the 12th day of cultures in vitro in the three groups. These results suggest that BL/LL macrophages exhibit a premature inability to undergo tuftsin stimulated microbicidal activity, which may possibly be reversed by serial dosage of tuftsin.

Blood Bactericidal Activity↗
PubMed1989

Lymphoproliferation and in vitro antibody synthesis in leprosy patients.

An in vitro system to assess B-cell function in leprosy patients is described. In vitro lymphoproliferation and antibody synthesis by peripheral blood mononuclear cells (PBMC) in response to pokeweed mitogen (PWM) and Formalin-treated Staphylococcus aureus Cowan I (FSA) from 31 leprosy patients and 13 healthy controls were studied. DNA synthesis was induced by both PWM and FSA in PBMC from all of the leprosy patients and control subjects. Lepromatous leprosy (LL) patients' cells showed higher responses to both PWM and FSA. However, these increases were not statistically significant. The levels of secreted IgM, IgG, or IgA were examined in the 7-day culture supernatants of PBMC cultured with or without PWM or FSA using an enzyme-linked immunosorbent assay. Wide individual variations were observed in in vitro antibody synthesis. IgM secretion in PBMC from normal subjects and various groups of leprosy patients in response to PWM and FSA was comparable. In vitro IgG secretion in response to PWM was the highest in cells from LL patients; it was significantly decreased in cells from tuberculoid leprosy (TT) patients (p less than 0.01). The levels in cells from borderline leprosy (BB) patients were intermediate in response to the same mitogen. Cells from leprosy patients as a group showed a higher spontaneous secretion of IgA in comparison with cells from normal subjects. Overall, the in vitro Ig secretion by PBMC in different patient groups appears to reproduce the spectrum of antibody levels observed in patients in vivo. Thus, the present in vitro culture system may help to delineate the mechanisms of B-cell dysregulation in leprosy.

Antibodies, Bacterial↗
PubMed1985

Natural emergence of antigen-reactive T cells in lepromatous leprosy patients during erythema nodosum leprosum.

Fifteen lepromatous leprosy (LL) patients undergoing erythema nodosum leprosum (ENL) reactions were compared with 13 stable, uncomplicated, anergic individuals of the same leprosy background. ENL patients showed significant antigen-induced leukocyte migration inhibition (migration index = 0.058 +/- 0.01), paralleling the values obtained with a responder tuberculoid leprosy population (migration index = 0.04 +/- 0.004). Both phytohemagglutinin-induced general T-cell proliferation and, more significantly, antigen-induced lymphoproliferation were enhanced during the acute phase of the reaction. Suppressor cell activity, monitored by a costimulant assay, showed enhanced antigen-stimulated suppression of mitogen responses. Interestingly, the improvement in in vitro T-cell responses was not reflected in dermal reactivity, since 48-h delayed-type hypersensitivity responses after intradermal injection of soluble Mycobacterium leprae antigens continued to be poor. After subsidence of reactional lesions, leukocyte migration inhibition, lymphoproliferation, and suppressor cell activity were reduced to the unresponsive state seen in stable LL patients. Significantly, perturbations of T-cell reactivity are detectable in ENL reactions, indicating the natural but transient emergence of antigen-induced T cells in LL.

Antigens, Bacterial↗
PubMed1979

Pediculosis capitis.

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Black or African American↗
PubMed1977

Study of the effects of certain drugs on experimental porphyria in rats.

The effect of ethanol, phenobarbitone, griseofulvin or chloroquine on 3,4-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-induced porphyria in rats has been studied in experiments lasting up to 40 days. Ethanol, phenobarbitone or griseofulvin given later, in addition to DDC, resulted in a clearly greater porphyrin excretion and liver porphyrin concentration than with DDC alone. Chloroquine at first increased, then decreased porphyrin excretion and liver porphyrin was lowered. No drug without DDC was porphyrogenic.

Animals↗