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Biomedical subjects

J Witkowski

Publications and source records attributed to J Witkowski.

At least 55 records · Page 3Linked to original sources
PubMed1981

Proportion of early E rosettes formed by peripheral blood lymphocytes from young and aged subjects.

The absolute number and percentage of early E-rosette-forming cells were determined in blood of young and aged subjects. The assay was carried out at low temperature (+4 degrees C) for 30 min in phosphate-buffered saline without any supplementation. The results indicate that both the absolute number and the percentage of early E rosettes detected are age-dependent, showing a tendency of reaching higher values in both aged females and males. There were also sex-related differences between young males and young females, but the values for aged males and females were approximately the same. The significance of the above-described early E rosette values is discussed and compared with early E rosettes detected by other methods.

Adult↗
PubMed1980

The relationship between mitogen-induced rosette formation and the ability of expressing alpha-naphthyl acetate esterase activity by mouse thymocytes.

Some percentage of mouse thymocytes have been shown to display positive ANAE reaction and some to form mitogen-induced rosettes with SRBC. Both types of cells are not homogeneous with regard to their density. Above 90% of rosette forming cells are simultaneously ANAE positive. Cells with such characteristics are more resistant to hydrocortisone than cells carrying ANAE marker but being negative in terms of rosette formation. The role of ANAE positive and rosette forming cells played in the course of thymocyte differentiation is discussed.

Animals↗
PubMed1979

A study of HLA-A, B, C, and DR specificities in pigeon breeder's disease.

The frequencies of HLA-A, -B, and -C antigens were determined among 51 symptomatic pigeon breeders, 102 asymptomatic pigeon breeders, and 100 normal blood donors. The HLA-DR specificities were also studied in 32 symptomatic and 29 asymptomatic pigeon breeders. All subjects were white. Symptomatic subjects were defined by the development of respiratory symptoms or decreased pulmonary function after aerosol challenge with pigeon serum. Asymptomatic subjects were comparably exposed to pigeons but had no pulmonary signs or symptoms after aerosol challenge. No significant association was found between any of the tested HLA specificities and pigeon breeders. This lack of association and the observed paucity of multiplex families indicate that HLA complex genetic factors tested in this study do not favor the development of pigeon breeder's disease in exposed persons.

Alveolitis, Extrinsic Allergic↗
PubMed1976

Comparison of the early chromatin reaction of the mouse thymocytes incubated with phytohemagglutinin and concanavalin A.

The preliminary activation of mouse thymocytes in vitro following exposure to the mitogens phytohemagglutinin and Concanavalin A, was compared. For this purpose the ratio of the fluorescence intensity for acridine orange-DNA complex at light wave length gamma = 590 nm to the fluorescence intensity of this complex at light wave length gamma = 530 nm was determined. It was shown that 100% of thymocytes showed an increase in chromatin activity under the influence of Con A within 15 minutes of incubation, but that following incubation with PHA an increase in activity occurred only in 25% of cells and was detectable only after 60 minutes of incubation. The results show that differences in the reactivity of thymocytes to PHA and Con A concern not only the late steps of activation such as RNA, protein and DNA synthesis, but also involve the earliest responses to the mitogen. The observed differences are discussed and correlated with the different degrees of maturity of the thymocytes.

Acridines↗