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.

Injuries to the phrenic nerve resulting in diaphragmatic paralysis with special reference to stretch trauma

Traumatic interruption of the phrenic nerve causing diaphragmatic paralysis occurs much more commonly than realized. Patients present with symptoms referable to the respiratory, gastrointestinal, or cardiovascular systems as a result of anatomic displacement of the respective organ (eventration). Symptoms often occur shortly after the injury but may be delayed for many years; consequently, prolonged follow-up of these patients is essential. If patients are symptomatic after trauma, judicious observation is dictated, since many will experience gradual return of normal diaphragmatic function over the succeeding six to twelve months. In those who remain significantly symptomatic, thoracotomy and imbrication of the eventration is a simple and effective surgical procedure.

Localization of alpha-fetoprotein in human and rat fetal livers. An immunohistochemical method using horseradish peroxidase

α-Fetoprotein (AFP) was successfully demonstrated in paraffin-embedded sections of human and rat fetal livers, by a multilayering immunohistochemical technique using the peroxidase-antiperoxidase system. Serial sections simultaneously subjected to immunofluorescence showed identical sites of localization in hepatocytic cytoplasm and sometimes in perivenous connective tissue. AFP-containing hepatocytes were located around efferent veins as well as randomly in the lobule. The immunoperoxidase technique has certain advantages over the immunofluorescence method which would justify the former's application in studies on the dynamics of AFP synthesis.