Hypopigmented lesions in early leprosy--a clinical and histological study

26 Patients of leprosy presenting with hypopigmented lesions were divided on morphological grounds into 3 Sub groups, Group I (9 patients) with well-defined single patch with moderate to complete sensory loss; Group II (8 patients) with single ill-defined lesion having partial sensory loss; and Group III (9 patients) having multiple hypo-pigmented patches with mild to moderate sensory loss. Epidermal atrophy was a conspicuous histological finding in all groups. Only patients in Group I showed epitheloid cells in dermal infiltrate with erosion of epidermis in one case. This group may be labelled as maculoanesthetic leprosy. Patients in Group II and III showed mononuclear cell infiltrate in dermis, around neurovascular bundles and appendages. They were histologically consistent with indeterminate leprosy. Follow-up biopsy after six to eight months of treatment showed healing of the lesion of reduction in the infiltrate in most cases.

Uptake of purine and pyrimidine nucleosides by macrophage-resident Mycobacterium leprae: 3H-adenosine as an indicator of viability and antimicrobial activity

Freshly extracted human- and armadillo-derived Mycobacterium leprae maintained within murine macrophages incorporated significant levels (p less than 0.05 to p less than 0.001) of 3H-adenosine and 3H-hypoxanthine by 6 and 9 days of the culture period. The incorporation of 3H-adenosine was twofold or more higher than 3H-thymidine in 10 out of 15 human-derived M. leprae isolates. Macrophage-adapted bacilli incorporated 10-14-fold higher levels of 3H-adenosine compared to the same bacilli maintained in axenic cultures. The incorporation of these two labels was inhibited by dapsone and rifampin, indicating the utility of in vitro radiometric assays for screening antileprosy drugs and drug sensitivity/resistance in patients.

Peroral pneumo colon--a double contrast technique to evaluate distal ileum and proximal colon

The technique of peroral pneumocolon (POPC) has been found to be simple and easy to obtain excellent double contrast visualization of the distal ileum and proximal colon. Thirty-four patients were subjected to the POPC examination of which 29 had undergone prior barium meal follow through studies. In 86.2% of these cases POPC was found to be superior as compared to conventional studies. In 5 patients who could not retain Ba-enema, POPC was performed as first line of investigation with 100% efficacy.

Thymic lymphoma cells as a model for complex-formation between thymocytes and thymic medullary epithelial cells

The formation of complexes between thymocytes and thymic stromal elements is known to be involved in T cell differentiation. We have previously described one type of lympho-stromal interaction involving CD4+ CD8+ thymocytes and a medullary epithelial cell line (E-5). In this study we report the potential for complex formation of two different thymic lymphoma cell lines (Ti-6 and RDM-4). Ti-6 cells were shown to adhere to the E-5 cells, while RDM-4 cells were totally incompetent. Phenotypic characterization of these cell lines suggests that immature thymocytes are not capable of forming complexes with medullary epithelium and that a certain level of differentiation is required to do so. Comparison of their phenotypes showed that the possibility of some classical T cell surface markers being the receptor for the E-5 ligand can be dismissed.

Accessory cell heterogeneity in lepromatous leprosy; dendritic cells and not monocytes support T cell responses

Dendritic cell (DC)-enriched cell populations from anergic lepromatous leprosy (LL) patients were found to be several-hundred-fold more efficient than monocytes (MO) in promoting antigen-induced T cell responses in autologous accessory + T cell cultures. Whereas, the use of autologous monocytes over a wide concentration range failed to stimulate Mycobacterium leprae-induced T cell proliferation, DC at concentrations as low as 0.1% induced significant proliferation in 9/15 and interferon gamma production in 14/15 LL patients. Four of the LL patients who failed to show proliferation were, however, able to secrete interferon gamma in the same T cell + DC co-cultures. DC were able to present particulate leprae antigens to autologous T cells. This preference for DC as an accessory cell was not shown when the cross-reacting antigen PPD was used in parallel co-cultures. Though tuberculoid leprosy patients showed some improvement in T cell proliferation with DC as compared to MO constituted co-cultures, this was not statistically significant. These results suggest that there is a heterogeneity in accessory cell requirement across the leprosy spectrum and that many lepromatous patients possess M. leprae-reactive functional T cells.

Fungal infections of ear with special reference to chronic suppurative otitis media

Fungus were found to take important role in ear infections of the 344 patients (CSOM 286, Otomycosis 44, Otitis externa 14), significant fungal infections (with positive smear and culture) were detected on 49%, 79.5%, 66.6% patients respectively. 84.8% patients were detected both by smear and culture, 14.1% patients by culture and 0.1% patients in smear preparation only. In CSOM patients, age predominated in 20-27 yrs group, sex in male below 30 yrs, and Aspergillus flavus, A. niger, Penicillium, A. fumigatus in mycelial fungus, Candida albicans, C. parapsillosis in yeast. But in 18 post antibiotic fungus infected patients Penicillium and A. niger were the important isolates. In otomycosis and otitis externa patients A. niger took the main role.

Involution of thymic epithelium and low serum thymulin bioactivity in weanling mice subjected to severe food intake restriction or severe protein deficiency

The volume of epithelium in the cortex and in the medulla of the thymus was compared in four groups of weanling male and female CBA/J mice. Well-nourished controls (C), food intake restricted (R), and animals given a low-protein diet ad libitum (LP) were fed from 23 to 37 days of age. Baseline controls (B) were studied at 23 days of age. Epithelial volume fraction was estimated for each group by point-counting morphometry on electron micrographs. Other mice were used to obtain group mean estimates of thymic index (mg/g live weight) and volume fraction of cortex and medulla (light microscope-level point-counting morphometry). Cortical and medullary epithelial volumes were calculated for each animal examined by electron microscopy by obtaining the live weight and applying, in sequence, the group mean thymic index, an assumed thymic density of 1.0 mm3/mg, the group mean cortical or medullary volume fraction, and the measured cortical or medullary volume fraction for that animal. Serum thymulin bioactivity was also measured in C, R, and LP mice. The results reveal thymic epithelial involution in the two most common rodent models of malnutrition, and suggest that this may contribute to the low serum thymulin levels found in malnourished experimental animals and humans.

Human T cell proliferative responses to particulate microbial antigens are supported by populations enriched in dendritic cells

The efficacy of dendritic cells in antigen presentation was studied in eight healthy subjects using a lymphoproliferation assay. Both particulate (Mycobacterium leprae, H37Ra) and soluble (PPD, tetanus toxoid) bacterial antigens were used as stimulants over a concentration range of accessory cells (monocytes (MO) and dendritic cells (DC)) varying from 10 to 0.1% in co-cultures using T-enriched cells. In general, co-cultures with T + MO and T + DC at all concentrations of accessory cells showed significant improvement of antigen-induced lymphoproliferation over PBMC cultures. The improvement in delta ct/min of T + DC co-cultures as compared to T + MO with parallel concentrations of accessory cells (P less than 0.05 to less than 0.01) was significant. Of the bacterial antigens used to test the antigen-presenting ability of DC, the particulate antigen (H37Ra) showed the most impressive improvement (380%) of T cell proliferation in DC reconstituted cultures as compared to monocytes. PPD, soluble protein derived from a similar tuberculosis strain of mycobacteria, was not presented as effectively as the particulate equivalent even though the donors of the appropriate cell combinations showed skin test reactivity to this antigen.

Thymic epithelial cells of severely undernourished mice: accumulation of cholesteryl esters and absence of cytoplasmic vacuoles

The thymic epithelium was compared in weanling male and female CBA/J mice when fed ad libitum and when subjected to severe food intake restriction for 14 days. The restriction protocol elicited predominantly a metabolic response to caloric deficit rather than to protein deficiency. Electron microscopy revealed intracytoplasmic accumulations of large, circular, homogeneously electron-dense profiles (with no limiting membrane) in a high proportion of cortical and medullary epithelial cells of thymuses from restricted mice, but not from controls. The electron-dense material was not preserved in the absence of osmium. Thin-layer chromatography (TLC) indicated elevated levels of free and esterified cholesterol, particularly the latter, in whole thymus extracts of restricted mice. Measurements of total cholesterol levels in the thymic extracts were consistent with the results obtained by TLC. In addition, cryostat sections of thymuses from restricted mice, but not from controls, exhibited numerous stained foci throughout the cortex and medulla when treated with oil red O (a general neutral lipid stain) or by the Schultz procedure which is specific for cholesterol. Collectively the results suggest accumulations of cholesteryl esters, together with some free cholesterol, as non-membrane-bound droplets in the cytoplasm of thymic epithelial cells of undernourished mice. It is also of interest that the lipid-laden epithelial cells exhibited none of the cytoplasmic vacuoles observed in controls and believed to be important in thymic hormone secretion. This work provides the first direct evidence of thymus epithelial abnormalities in severe protein-energy malnutrition.

Radiometric macrophage culture assay for rapid evaluation of antileprosy activity of rifampin

The antileprosy effect of rifampin was evaluated by a newly developed rapid in vitro assay wherein 31 human-derived strains and 1 armadillo-derived strain of Mycobacterium leprae were maintained for 2 and 3 weeks, respectively, in murine and human macrophages in the presence of [3H]thymidine. Of these strains, 27 showed significant incorporation of the radiolabel in cultures of live bacilli as compared with control cultures of heat-killed bacilli of the same strain. Consistent and significant inhibition of [3H]thymidine uptake was observed in M. leprae resident cultures with 3 to 200 ng of rifampin per ml as compared with similar cultures without the drug. In general, an increase in percent inhibition was seen from 3 to 20 ng/ml, with marginal increases at 40, 50, and 100 ng/ml. M. leprae strains appear to be remarkably susceptible to this drug in the in vitro assay.

Rapid, radiolabeled-microculture method that uses macrophages for in vitro evaluation of Mycobacterium leprae viability and drug susceptibility

This paper describes a microculture rapid assay using radiolabeling and mouse macrophages to determine the viability and the drug susceptibility or resistance of Mycobacterium leprae. Comparison of M. leprae resident macrophage cultures maintained in 96-well flat-bottomed plates showed results for viability and susceptibility or resistance to dapsone that were similar to results for concurrent cultures in Leighton tubes with greater numbers of bacilli and macrophages.

Lack of correlation between morphological index and viability as assessed by the uptake of 3H-thymidine by macrophage resident M. leprae

Thirty strains of M. leprae derived from skin biopsies of lepromatous leprosy patients were scored for Morphological Index (MI) and concurrently maintained for 2 weeks in macrophage cultures containing 3H thymidine. Selective and significant incorporation of the radioactive label was observed in cultures containing freshly extracted M. leprae as compared to control cultures with autoclaved bacilli from the same biopsy. The percentage incorporation of 3H thymidine ranged from 103 to 1140%. Morphological Index of the bacilli from these individuals varied from zero to 8. Six cultures containing bacilli with MI of less than or equal to 1 and 3 containing bacilli with MI of zero showed significant incropration of 3H thymidine. There was no correlation between the percent of solid or beaded bacilli in the inoculum and the ability of M. leprae to incorporate 3H thymidine in the macrophage cultures.

Studies on allergenic algae of Delhi area: botanical aspects

To study distribution of algae in and around Delhi aerobiological surveys were undertaken for two consecutive years (September, 1972, to August, 1974). The surveys were accomplished by (a) slide exposure method and (b) culture plate exposure method. A total of 850 slides were exposed using Durham's gravity sampling device. Of these, 560 slides were exposed during 1973 (272 slides at two meter and 288 at ten meter height) and the rest (290 slides) were exposed during 1974 at ten meter height. A total of 858 culture plates were exposed (276 for one hour and 282 for two hours) during 1973 and the rest (300 culture plates) were exposed during 1974 at ten meter height for two hours duration only. Air was found to be rich in algae flora during the months of September to November. The dominant forms of algae present were all blue greens. This might be due to the relative greater resistance of blue green algae to unfavorable conditions.