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Biomedical subjects

C C Shepard

Publications and source records attributed to C C Shepard.

At least 55 records · Page 3Linked to original sources
PubMed1975

Histocompatibility antigens in leprosy.

Results of HL-A typing are presented in 82 patients with leprosy and 50 normal Filipinos from Cebu, and 144 normal Filipino immigrants from the Luzon area. Comparisons of HL-A antigen frequencies among the total patients and normals of Cebu showed no statistically significant differences; however, HL-A10 was increased in frequency among the patients with lepromatous disease compared to the normals, and HL-A5 was increased among the tuberculoid patients compared to the lepromatous patients. None of these comparisons was statistically significant when corrected for the number of antigens tested. Comparisons of HL-A antigen frequencies between normal Filipinos of the Cebu and Luzon regions showed increased W-5 in the Luzon population (corrected p smaller than 0.025).

California↗
PubMed1975

Acedapsone (DADDS) treatment of leprosy patients in the Karimui of Papua New Guinea: status at six years.

Acedapsone (DADDS), a repository sulfone given by injection five times a year, has been used since 1967 for the treatment of all leprosy patients in the Karimui, an area of diffic-lt access. More than 460 patients have been treated, 336 beginning in November 1967 and continuing through the latest assessment 6 years later. The injections have been well received and they have been administered very regularly. Clinical observations were begun before 1967, as a base-line of assessments was available for the patients whose disease appeared before that time. The response to DADDS therapy has been satisfactory except in 5 of the 28 multibacillary patients in whose smears solid-staining Mycobacterium leprae have reappeared. M. leprae was isolated in mice from three of these patients; one strain has been proven to be completely susceptible to dapsone (DDS), and the other two very probably are. DDS levels in the plasma of these five patients were normal and well above the minimal inhibitory concentration. The most probable explanation is that a few viable M. leprae survived in the presence of inhibitory concentrations of DDS for the 4 to 6 years during which dead bacilli were disintegrating and disappearing from the tissues. The other 23 multibacillary patients responded satisfactorily. The decrease in the number of M. leprae in the skin smears has been most prompt in patients with low initial bacterial loads and in those with borderline lepromatous diagnoses. A high initial bacterial load and a fully lepromatous diagnosis were associated with a slow initial loss of M. leprae in the 1st year, followed by a more rapid loss the next year. All of the multibacillary patients have now been treated by the addition of a 90-day course of rifampicin.

Acetamides↗
PubMed1971

Relationship Between the Staining Quality of Mycobacterium leprae and Infectivity for Mice.

The proposal has been made that only solidly staining forms of Mycobacterium leprae are viable. On the basis of a previous study, solidly staining bacilli were defined as those that stained completely and darkly throughout their length. A study was carried out to correlate the proportion of solidly staining bacilli in inocula with the infectivity and rate of appearance of bacillary growth in inoculated mice. The inocula originated in skin biopsy specimens of patients and in mouse passage material; there were 347 inocula suitable for study. The rate of appearance of bacillary growth in inoculated mice confirmed the hypothesis that nonsolid bacilli are inert and nonviable and that all growth originates from the solidly staining organisms. The minimal infectious dose was determined in four suspensions and was found to range from 40 to 3 solidly staining bacilli.

Journal Article↗
PubMed1971

Hereditary Characteristic that Varies Among Isolates of Mycobacterium leprae.

Isolates of Mycobacterium leprae in mouse foot pads were found to differ in two related properties, the average rate of growth between inoculation and harvest (G) and the number of bacilli in the harvest (H). For "fast" strains the median values for G were less than 25 days per generation, and the median values for H were above 10(6.1). For "slow" strains the median values for G were above 30, and the median values for H were below 10(5.6). The G and H values for the 59 isolates for which data were available formed a continuous spectrum between the two extremes; there was no correlation with dapsone resistance. The fastness characteristic was stable; it did not change on passage in mice and was in agreement when more than one isolate had been made from the same patient. No important differences were apparent according to geographic origin of the infection of the patient. Histological studies showed that fast strains grew to a higher level without inducing the infiltrate of lymphocytes and macrophages that appears at the end of the logarithmic phase of growth in mouse foot pads. Although fast strains often had higher ratios of solidly staining (and presumably viable) bacilli in the inoculum, the fast-slow difference was not accounted for by the solid ratio. Slow strains differed from fast by having longer times until harvest and by having fewer generations of growth, even when their frequently lower solid ratios were taken into account.

Journal Article↗
PubMed1971

The first decade in experimental leprosy.

Considerable developments have occurred in the application of the method for growing Mycobacterium leprae in the mouse foot-pad since it was first described about 10 years ago. The method has been used to study growth curves and histology in normal and in thymectomized irradiated mice, to identify supposed isolates of Myco. leprae that have been made in tissue-culture or in non-living media, to evaluate tests of experimental vaccines, to investigate applications to clinical investigations (the loss of infectivity during chemotherapy as a means of monitoring a drug trial, the demonstration of drug-resistance, and the clinical problem of the patient who responds poorly to therapy), and to study new drugs-e.g., dapsone, acedapsone, clofazimine, and rifampicin.

Animals↗