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V N Sehgal

Publications and source records attributed to V N Sehgal.

At least 19 recordsLinked to original sources
PubMed1992

Reconstruction of anti-leprosy drug depleted complement haemolytic activity by addition of zymosan-treated sera (a source of C142) and CratEDTA (a source of C3-C9).

This paper describes the mechanism of in vitro interaction of human serum complement system with anti-leprosy drugs (dapsone and clofazimine) and anti-lepra reaction drugs such as chloroquine. These drugs could inhibit the complement-mediated lysis of erythrocytes both via direct and alternative pathways, but only at hypertherapeutic doses. Attempts were made to restore the drug depleted complement-mediated lysis of erythrocytes by adding zymosan-treated guinea-pig sera (a source of C142) and also by adding Crat-EDTA sera (a source of C3-C9). Destroyed complement-mediated haemolytic activity by dapsone could be restored by early complement (C142) components, while complement-mediated haemolytic activity blocked by clofazimine could be regenerated by adding both late (C3-C9) and early (C142) complement component. However, chloroquine-mediated inhibition of the complement-mediated haemolysis activity could not be appreciably restored by adding both early and late complement reagents.

Animals↗
PubMed1992

Anti-leprosy drugs inhibit the complement-mediated solubilization of pre-formed immune complexes in vitro.

Incubation of pre-formed immune complexes (IC) (125I-HSA--anti-HSA) with normal human serum resulted in solubilization of IC. When various anti-leprosy drugs were added to human sera, solubilization of IC was fairly explicit with clofazimine, whereas this effect was marginal with dapsone. Rifampicin hardly displayed this effect. Aspirin, chloroquine, and prednisolone, the drugs used in addition to multi-drug therapy to control reactions in leprosy, were in a position to inhibit the solubilization of 125I HSA--anti-HSA by normal serum only at a very high dose. From the current data of the inhibition of solubilization of pre-formed IC along with our earlier observations on the modulation of complement-mediated haemolysis by these drugs, it may be possible to postulate that clofazimine as well as chloroquine affect early complement components. This may in turn be responsible for preventing the deposition of C3 complement onto IC.

Antigen-Antibody Complex↗
PubMed1992

In vivo effects of anti-leprosy drugs on the rat peritoneal macrophages and lymphocyte subpopulations.

The present study describes the in vivo effects of anti-leprosy drugs on rat peritoneal macrophages and T-cell homeostasis. It was observed that BCG-elicited rat peritoneal macrophages produced more H2O2 and expressed more Ia antigen on their cell surfaces compared with resident peritoneal macrophages. Furthermore, elicited macrophages isolated from rats administered multidrug therapy (MDT), consisting of dapsone, clofazimine and rifampicin in high dose (10 x MDT) released more O2-. On the contrary, there was a significant decrease in the Ia antigen expression on these macrophages. Anti-leprosy drug treatment in high dose (10 x MDT) decreased the total number of blood T-helper (W3/25+) cells and increased the total number of blood T-suppressor (OX-8+) cells which resulted in a significant decrease in a W3/25: OX-8 ratio. Electron microscopy of elicited macrophages isolated from 10 x MDT treated rats showed development of many filipodia compared with control macrophages. These data show that 10 x MDT treatment in rats for 1 month alters the homeostasis of blood T-cell subpopulations which perhaps decreases the Ia expression on macrophages. However, the increase in O2- production and the appearance of filipodia on the macrophages is due to a direct effect of drugs on the macrophages. MDT treatment for 1 month in a therapeutic dose has no effect on the above-mentioned parameters.

Animals↗
PubMed1992

Inoculation lupus vulgaris.

An 11-years-old girl with lupus vulgaris on the right buttock following inoculation is described. The diagnosis was formed by the history, morphological characteristics, Mantoux test, histopathology, and was supported by an affirmative response to short course intensive chemotherapy (6 months). This route of infection acquires special significance with the worldwide-spread of HIV infection.

BCG Vaccine↗
PubMed1992

Tuberous sclerosis and spina bifida occulta.

An interesting occurrence of tuberous sclerosis and spina bifida occulta is described, highlighting their unique and previously undescribed association in a 5-year-old boy.

Child, Preschool↗
PubMed1992

Donovanosis.

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Granuloma Inguinale↗
PubMed1992

Significance of antibodies to phenolic glycolipid-I in leprosy diagnosis.

A gelatin particle agglutination assay for the detection of anti PGL-I antibodies in 40 clinically diagnosed and variously classified groups of leprosy cases revealed elevated PGL-I antibody titers in 85% of cases. In contrast, the slit-skin smear examination was positive in only 30% of cases. It was further observed that, out of 28 cases with Bacteriological Index (B.I.) zero, 22 cases (78.5%) had significant levels of PGL-I antibodies. There was no case in which the slit skin smear was positive and the PGL-I antibody titer was not significant. The elevated titers of PGL-I antibody better correlated (84%) with histopathological findings than did B.I. Thus it was concluded that estimation of PGL-I antibody titer is a better supplement to clinical diagnosis than B.I. Significant levels of PGL-I antibody were seen in 85% of cases who had no earlier chemotherapy or were treated for less than 2 months. Similar findings were observed in 12 patients who were on MDT for more than 5 months but for less than 2 years. In order to determine the significance of anti PGL-I antibodies in monitoring the response of patients to chemotherapy, a longer follow up with a greater number of cases should be contemplated.

Antibodies, Bacterial↗
PubMed1992

Lymphocyte adenosine deaminase activity (L-ADA) in leprosy, during and after treatment of reactions.

Twenty-five patients with type 1 (lepra) and type 2 (E.N.L.) leprosy reactions were studied for lymphocyte adenosine deaminase activity (L-ADA), during and after treatment of the reactions, using a standard technique, in order to establish its pattern and if possible, its value in assessing the course of reactions. The results were compared with those from 30 control subjects, comprising 10 normal healthy adults, 10 patients with borderline tuberculoid (BT) leprosy, four patients with borderline lepromatous (BL) leprosy and six patients with lepromatous (LL) leprosy. The level of L-ADA in the leprosy controls was higher than that of normal healthy subjects. The L-ADA values in patients with different types of reactions were about 10-fold higher than those obtained from leprosy controls, emphasizing a possible role in assessing reactions in leprosy. However, there was no significant variation in L-ADA levels, either between the various leprosy controls or reaction groups, before and after treatment.

Adenosine Deaminase↗
PubMed1992

Peripheral T lymphocytes and their subsets in cutaneous tuberculosis.

Fifty-four patients with cutaneous tuberculosis, consisting of 23 with lupus vulgaris, 22 with scrofuloderma, and nine with verrucosa cutis, were investigated for cell-mediated immunity, through estimation of peripheral total T lymphocytes (CD3+), CD4+ (helper/inducer), and CD8+ (cytotoxic/suppressor) lymphocytes, by immunohistochemical staining of peripheral blood smears, using specific monoclonal antibodies and the alkaline phosphatase-antialkaline phosphatase (APAAP) method. Absolute values of total T lymphocytes (CD3+), and CD4+ and CD8+ subsets, were found to be significantly raised in scrofuloderma, but the percentage values and the CD4+/CD8+ ratio remained unaltered. In tuberculosis verrucosa cutis, only the percentage of the CD8+ subset of T lymphocytes was found to be significantly lowered, and this altered the CD4+/CD8+ ratio. No significant change was observed in the peripheral blood T cells and their subpopulations in patients suffering from lupus vulgaris.

Adolescent↗
PubMed1992

Reaction in leprosy: acute phase reactant response during and after remission.

Sera from 25 patients with type 1 (Lepra), upgrading and downgrading, and type 2 (erythema nodosum leprosum [ENL]) reactions were assayed, during the reaction and after its clinical remission, for changes in levels of alpha-1-antitrypsin (A1A) and C-reactive protein (CRP). The results were compared with those from normal healthy adults and patients of leprosy without history and/or clinical evidence of reaction. The A1A levels correlated better with changes in status of type 1 reaction; whereas CRP levels correlated well with alterations in type 2 reactions and were definitely superior to A1A in this situation for monitoring the course of these episodes.

Adolescent↗
PubMed1992

Urticaria.

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Antigen-Antibody Complex↗
PubMed1991

Effect of anti-leprosy drugs on superoxide anion production by rat peritoneal macrophage with special reference to light exposed clofazimine.

The present study describes the in vitro effect of anti-leprosy drugs on superoxide anion (O2-) production by rat resident peritoneal macrophages. Of the three drugs tested i.e. clofazimine, rifampicin and dapsone, the first was most effective in increasing O2- production in a dose dependent manner, while rifampicin had some stimulatory effect and dapsone exhibited minimal action. Furthermore, when clofazimine and dapsone were added together it was observed that the increase of O2- production by macrophages due to clofazimine was not significantly altered by the addition of dapsone. Moreover, it was found that killed Mycobacterium leprae could induce a lesser amount of O2- production in comparison to that of Staphylococcus aureus and the enhancement of O2- release due to clofazimine was stimulus dependent. This increase of O2- release after addition of clofazimine was inhibited by the addition of p-bromophenacyl bromide. Another interesting finding was that the enhancement of O2- production by clofazimine gradually decreased as clofazimine was exposed to light for days. On further investigation it was found that ultraviolet, NMR, infrared and mass spectra of the light unexposed and exposed drug were similar, but the diffusion current of the polarogram of light exposed drug was remarkably more than that observed in light unexposed drug, indicating, thereby, a possible increase in the electron accepting capacity of the light reacted molecule. As far as we know this is the first report describing the effect of light exposed clofazimine on the respiratory burst activity of macrophages.

Animals↗