Search PubMed⌕ Search

Biomedical subjects

C Blank

Publications and source records attributed to C Blank.

9 recordsLinked to original sources
PubMed1992

Murine epidermal Langerhans cells are potent stimulators of an antigen-specific T cell response to Leishmania major, the cause of cutaneous leishmaniasis.

Cutaneous leishmaniasis is initiated by the bite of an infected sandfly and inoculation of Leishmania major parasites into the mammalian skin. Macrophages are known to play a central role in the course of infection because they are the prime host cells and function as antigen-presenting cells (APC) for induction of the cell-mediated immune response. However, in addition to macrophages in the dermis, the skin contains epidermal Langerhans cells (LC) which can present antigen (Ag) to T cells. Therefore, using a murine model of cutaneous leishmaniasis, we analyzed the ability of epidermal cells to induce a T cell response to L.major. The results demonstrated that freshly isolated LC, but not cultured LC, are highly active in presenting L.major Ag in vitro to T cells from primed mice and to a L.major-specific T cell clone. Furthermore, freshly isolated LC had the ability to retain L.major Ag in immunogenic form for at least 2 days. Their efficiency was much greater than that of irradiated spleen cells, a standard population of APC. LC stimulated both T cell proliferation and production of the lymphokines interleukin (IL)-2 and IL-4. The response was Ag specific and could be induced by lysate of L.major parasites and by live organisms. The data suggest that epidermal LC are important APC in cutaneous leishmaniasis. They may perform a critical function by capturing L.major Ag in the skin and presenting it either to quiescent T cells circulating through the draining lymph node or locally to T effector cells infiltrating the cutaneous lesion.

Animals↗
PubMed1992

Reevaluation of benzene exposure for the Pliofilm (rubberworker) cohort (1936-1976).

The Pliofilm cohort is the most intensely studied group of workers chronically exposed to benzene. Information on this cohort has been the basis for regulations and/or guidelines for occupational and environmental exposure to benzene. Rinsky et al. (1986, 1987) and Crump and Allen (1984) developed different approaches for reconstructing the exposure history of each member of the group. The predicted levels of exposure, combined with the data on the incidence of disease, have been used to estimate benzene's carcinogenic potency. In this paper, recent information from worker interviews and historical records from the National Archives and elsewhere were used to evaluate the accuracy of prior exposure estimates and to develop better ones for the cohort. The following factors were accounted for: (1) uptake of benzene due to short-term, high-level exposure to vapors, (2) uptake due to background concentrations in the manufacturing building, (3) uptake due to contact with the skin, (4) morbidity and mortality data on workers in the Pliofilm process, (5) the installation of industrial hygiene engineering controls, (6) extraordinarily long work weeks during the 1940s, (7) data indicating that airborne concentrations of benzene were underestimated due to inaccurate monitoring devices and the lack of adequate field calibration mated due to inaccurate monitoring devices and the lack of adequate field calibration of these devices, and (8) likely effectiveness of respirators and gloves. Our estimates suggest that Crump and Allen (1984) overestimated the exposure of workers in some job classifications and underestimated others, and that Rinsky et al. (1981, 1986) almost certainly underestimated the exposure of nearly all workers. Airborne concentrations of benzene at the St. Marys facility during the years of its operation were found (on average) to be about half those of the two Akron facilities. Our analysis indicates that short-term, high-level exposure to benzene vapors and dermal exposure significantly increased (by about 25-50%) the total absorbed dose of benzene for some workers. One of the key findings was that, unlike prior analyses, the three facilities probably had significantly different airborne concentrations of benzene, especially during the 1940s and 1950s.

Air Pollutants, Occupational↗
PubMed1991

Perinephric inflammatory process following extracorporeal shock wave lithotripsy.

A patient with large branched staghorn calculi was treated with ESWL. She suffered from recurrent urinary tract infections. Following ESWL she developed a perinephric abscess, which necessitated percutaneous drainage. The clinical course is described and a possible pathogenesis of perinephric abscess following ESWL is suggested.

Abscess↗
PubMed1988

Embryonal carcinoma of testis in elderly men.

A rare case of pure embryonal carcinoma of the testis in a 63-year-old man is presented. The literature on germ cell tumours in men 60 years of age and older is also presented.

Age Factors↗
PubMed1987

Vascular polyps of ureter associated with megacalycosis and nephrolithiasis.

Multiple benign vascular polyps of the ureter are rare, and the associated congenital megacalycosis and nephrolithiasis are very uncommon. Herein we report a case with vascular polyps of the right ureteropelvic junction dissociated with extensive hydronephrosis which was considered to be megacalycosis. Clinical features and treatment modalities are reviewed.

Adolescent↗
PubMed1987

Fibroepithelial polyp of the renal pelvis.

Benign tumors of the renal pelvis are rare, with less than 10 cases reported in the literature. The fibroepithelial polyp, a benign mesodermal tumor, seems to be the most common type. We report a case of a fibroepithelial polyp of the renal pelvis, and discuss its clinical features and diagnostic pitfalls.

Adult↗
PubMed1987

Corticosterone response underlying tolerance to stress induced by a gaseous (nitrous oxide) environment.

Conditioned taste aversion (CTA) was demonstrated in rats following a single pairing between ingestion of a novel saccharin solution (CS) and 60 min. inhalation of an 80% N2O2:20% N2O gas mixture (UCS). CTA from a single novel CS-N2O UCS pairing was achieved by methodological improvements including: an inhalation chamber for small animals that achieved complete gas diffusion, an increased UCS duration (60 min. of inhalation) and a decreased CS-UCS interval (1 min.). The increased N2O UCS inhalation probably contributed to CTA, since no duration less than 60 min. of N2O inhalation produced significantly greater plasma corticosterone elevation than 60 min. of N2:O2 inhalation. The hypothesis that CTA is stress-induced was supported, in that plasma corticosterone levels were elevated by N2O inhalation and adrenal catecholamines (CA) were depleted. Further, after 4 N2O pretreatments, which produced partial behavioral tolerance to N2O treatment, plasma corticosterone elevation abated somewhat. However, corticosterone level also was raised by N2:O2 treatment. As a result, abatement of corticosterone elevation cannot account for behavioral tolerance to N2O-induced CTA, though it may be a contributor. Since adrenal CA were depleted by N2O inhalation, this response also might abate and underlie or contribute to behavioral tolerance.

Animals↗