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Biomedical subjects

J Curtis

Publications and source records attributed to J Curtis.

At least 145 records · Page 8Linked to original sources
PubMed1981

A colony assay for blast cell progenitors in non-B non-T (common) acute lymphoblastic leukemia.

A clonal method in cell culture is described that permits the quantitation of blast precursors in common (non-T, non-B) ALL; the method also yields information about progenitor properties, based on analysis of cells in colonies. The technique is identical to that used successfully for normal and malignant B-cell progenitors except that it requires culture at below O2 tension (5%-7%); mononuclear cells from blood or marrow are depleted of T cells and cultured with media conditioned by T cells in the presence of phytohemagglutinin and irradiated T cells. Cultures are incubated for 5-7 days in a moist atmosphere at 5% CO2 and 5%-7% O2. Colonies were obtained from marrow or blood of 16 of 18 ALL patients. Cells in colonies had the same characteristics (E-, slg-, cALL+ and clgM+ or clgM-) as the cells in the patient. By replating pooled colonies, self-renewal of progenitors was shown. The findings are considered in light of a model of leukemic blasts that depicts such populations as lineages maintained by progenitors that either renew themselves or give rise to blast cells with little or no proliferative capacity.

Antigens, Neoplasm↗
PubMed1981

A lack of correlation between antigen-specific cellular reactions and resistance to Mycobacterium lepraemurium infection in mice.

Following infection subcutaneously in the footpad with 10(7) Mycobacterium lepraemurium organisms C57BL mice were able to limit multiplication of organisms at the infection site for the 6 months studied and to limit organism spread to the draining lymph node. Large numbers of organisms were present in the footpad and draining lymph node of BALB/c mice at 6 months. In spite of this difference in local immunity the changes in cellular reactivity to specific antigen as assessed by the delayed footpad response and the in vitro proliferative response of draining lymph node cells were similar in the two strains over the time studied.

Animals↗
PubMed1981

Differences in cell-mediated immune responses of 'high-resistance' and 'low-resistance' mice to a nonpathogenic mycobacterium.

The kinetics of the footpad response of bacillus Calmette-Guérin (BCG)-infected mice to soluble BCG antigens were compared in two strains of mice with different degrees of susceptibility to Mycobacterium lepraemurium. For the first 21 days the responses of the 'high-resistance' C57BL and the 'low-resistance' BALB/c to the nonpathogenic BCG were similar to that produced when the pathogenic mycobacterium was used. After 4 weeks the kinetics of the BALB/c mice changed and resembled that of the C57BL mice. The change in kinetics was compared with circulating antimycobacterial antibody levels and the response of draining lymph node cells in the antigen-specific lymphocyte transformation test. A dissociation was found between the kinetics of the delayed footpad response and the lymphocyte transformation response. Since both strains of mice are equally resistant to BCG, it appears that the delayed footpad response cannot be used as an indicator of host resistance in all mycobacterial infections.

Animals↗
PubMed1980

Activation of the alternative pathway of complement by mycobacteria and cord factor.

The ability of a number of mycobacteria and some of their components to activate complement was examined. Mycobacterium bovis BCG (Glaxo strain), Mycobacterium leprae, Mycobacterium lepraemurium, and cord factor activated the alternative pathway of complement in normal human serum and normal and C4-deficient guinea pig sera and generated biologically active products. BCG (Pasteur strain) and muramyl dipeptide did not activate complement. The relevance of activation of complement by mycobacteria to their induction of granulomas is discussed.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1979

Mitsuda-type lepromin reactions as a measure of host resistance in Mycobacterium lepraemurium infection.

The footpad reaction to autoclaved whole Mycobacterium lepraemurium organisms (MLM lepromin) in high-resistance (C57BL) and low-resistance (BALB/c) mice was studied. Infected C57BL mice gave a prolonged footpad response persisting for 4 weeks after skin testing with high and low doses of lepromin. This was accompanied by mononuclear cell infiltration. Uninfected C57BL mice gave no response. The majority of infected BALB/c mice gave no increase in footpad thickness. However, a high proportion of infected and control BALB/c mice tested with the high dose showed mononuclear cell infiltration which resembled that in C57BL mice. The low dose caused little infiltration in infected or control BALB/c mice. The course of infection in the two strains was different. Dissemination of organisms from the infected footpad was minimal in C57BL mice 5 months after infection. In BALB/c mice, dissemination to the draining lymph node and to some extent to the liver had occurred by 5 months. The draining lymph node of BALB/c mice showed histological evidence of local antibody formation, which uas not found in C57BL mice. On the basis of these findings, it was possible to fit murine leprosy in these two strains into a classification similar to that used for human leprosy.

Animals↗
PubMed1979

Development of delayed hypersensitivity responses in Mycobacterium lepraemurium infections in resistant and susceptible strains of mice.

C57Bl mice are relatively resistant to a moderate subcutaneous infection with Mycobacterium lepraemurium while BALB/c mice are much more susceptible. Cutaneous delayed hypersensitivity reactions which develop in the first 3 weeks of infection were compared in these two strains of mice. Both strains gave a peak of delayed hypersensitivity between 6 and 10 days after infection which was followed by a period of low reactivity before the development, in the third week, of a stable persistent delayed hypersensitivity reaction. There was no difference between the strains in the size at 24 h of the delayed hypersensitivity reaction but the reactions differed in their kinetics. The low resistance strain, BALB/c, gave a Jones-Mote-type of response while the high resistance strain gave a response which could be described as a tuberculin-type reaction.

Animals↗
PubMed1978

Number of response alternatives and spatial arrangement on a visual discrimination task.

Normal children, 30 each from ages 5 and 7 yr., were administered a visual discrimination test through a programmed learning machine. Visual discrimination was defined as a match-to-sample task in which subjects pointed to the geometric form, number, or printed letter of the alphabet that matched the stimulus form. Procedures were designed to eliminate learning variables. Although both age groups performed well, there was a statistically significant difference in the total performance at the two ages. A 3-way analysis of variance showed age, number of response alternatives, and type of stimulus form were significant variables; all interactions were significant. It appeared that the significant variable for the 5-yr.-olds was the type of geometric configuration, while the variable most important for the 7-yr.-olds was the number of response alternatives. Patterns of errors on the most difficult item showed the 5-yr.-olds made errors involving a reversal or rotation of the stimulus figure, while the 7-yr.-olds made errors involving some detail of the stimulus figure.

Child↗
PubMed1977

Circulating T-cell numbers and their mitogenic potential in leprosy--correlation with mycobacterial load.

The effect of treatment and mycobacterial load on circulating T-cell numbers and their functional ability was investigated in forty-one patients with leprosy. Both early binding T cells and their responses to phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) were profoundly and uniformly depressed in untreated, and partially treated, bacilleferous lepromatous leprosy (LL) patients as compared with normal subjects and tuberculoid patients. On elimination of mycobacteria, subsequent to chemotherapy, LL patients regain normality in T-cell numbers and their functions. On the other hand, the specific response of lymphocytes to M. leprae did not alter with decrease in mycobacterial load. It appears that the decrease in T-cell numbers and the deficit in their mitogenic potential is a secondary consequence of disease and is related to the antigenic load in patients with lepromatous leprosy.

Antigens, Bacterial↗
PubMed1975

Lymphatic visualization during hip arthrography.

Lymphatic visualization at arthrography has been reported previously in patients with rheumatoid arthritis. The authors describe this phenomenon in 4 patients undergoing arthrography of the hip following prosthetic surgery, only one of whom had a history of rheumatoid arthritis. It is suggested that lymphatic visualization is not a reliable indicator of any specific type of arthritis, but rather an ancillary sign of inflammation, and that it may occur whenever lymphatic hyperplasia or increased synovial membrane permeability is present.

Aged↗
PubMed1975

Lymphocytes devoid of T and B cell markers in chronic lymphatic leukemia.

Peripheral lymphocytes of 16 patients with chronic lymphatic leukemia were studied for B and T cell markers with peroxidase-labelled anti-immunogloulin antisera and complement and spontaneous rosetting techniques. Increased numbers of B cells and normal numbers of T cells were noted. A significant observation was the presence of a large proportion of circulating lymphocytes without the conventional markers for T and B cells. This finding is correlated with clinical features.

Animals↗