Biomedical subjects

B Tartakovsky

Publications and source records attributed to B Tartakovsky.

57 records · Page 4Linked to original sources

PubMedDate not supplied

Modeling and analysis of co-immobilized aerobic/anaerobic mixed cultures.

Systems of co-immobilized microorganisms are highly effective for conducting two or more consecutive bioprocesses within close proximity of the source and the sink of substrates. In this work, a general model of a co-immobilized aerobic/anaerobic bacterial system was developed and analyzed. The model was used to optimize pellet design and to study the effect of slow cell growth on process efficiency. The analysis demonstrated that co-immobilization of bacterial species accelerates the rate of biotransformation and provides complete transformation of toxic intermediates.

Aerobiosis↗

PubMedDate not supplied

Impairment of cellular immunity in patients with malignant external otitis.

Immunological studies were performed on 4 elderly diabetic patients with Malignant External Otitis caused by Pseudomonas aeruginosa. Impairment of cellular immunity was found. Skin tests for delayed hypersensitivity to PPD, SK-SD and Mumps antigen were negative and stimulation rates of peripheral blood lymphocytes by PHA, Con-A and PWM were depressed in all 4 patients. Serum immunoglobulins and complement levels were normal except in one case in which paraprotein IgG was found. Peripheral blood lymphoid cell markers and the neutrophil nitroblue tetrazolium (NBT) test were within normal limits in the 2 patients tested. These results indicate that cellular immune deficiency predisposes to the development of Malignant External Otitis in elderly diabetic patients.

Aged↗

PubMedDate not supplied

The poised B cell: lymphokines induce an Ia-increase and antigen-presenting function in B cells.

Individual murine B cells express a wide range of Ia densities on the plasma membrane. Here we demonstrate that a dramatic increase in B-cell Ia could be induced by overnight exposure to an uncharacterized lymphokine (LK). Membrane I-A and I-E molecules were both increased after LK treatment, whereas membrane IgM remained unchanged. Two subpopulations of B cells were identified, based on their requirements for expressing maximal Ia; one subpopulation required only LK, the other required both LK and T cells in the overnight culture. Functional changes accompanied the Ia increase. The functional capacity to present antigens to T cells was lacking in normal resting B cells, but was acquired following LK treatment. We suggest that the LK-treated B cell has achieved a new differentiation state, one of preparation for interaction with T cells. We term this state the "poised" B cell, and propose that B cells in the poised state may significantly contribute to T-cell activation as antigen-presenting cells. Moreover, poised B cells may themselves find an advantage over normal B cells in successfully acquiring T-cell help.

Animals↗