Biomedical subjects
Publications and source records attributed to P Kaur.
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The immunoregulatory activity of bone marrow leukemic blasts from five patients with null-cell acute lymphoblastic leukemia (ALL) and two children with T-cell ALL was evaluated. Blasts were studied in co-culture for their effects on the proliferative responses of normal allogeneic peripheral blood lymphocytes to phytohemagglutinin. Mitomycin C-treated null cell ALL blasts from two of five children suppressed the proliferative responses of normal responder cells by 80% and 58% whereas those from two other children enhanced the responses by 118% and 31%. T-cell leukemic blasts from one patient with T-cell ALL exhibited helper cell activity (26%) and T-leukemic blasts from the other demonstrated suppressor cell activity (53%). The helper cell activity of leukemic blasts was associated with stimulating capacity of null blasts in one-way mixed lymphocyte reactions. In six of seven cases, incubation of blast cells with concanavalin A (20 microgram/ml) for 48 hours prior to co-culture with responder cells did not result in the generation of significant suppressor cell activity. Our study suggests that leukemic blasts from certain patients with 'null' and T-cell ALL may possess spontaneous helper or suppressor cell immunoregulatory activity. This functional heterogeneity of leukemic blasts may help in subclassifying the ALL.
The genotoxic activity of diesel exhaust emissions, particulate matter, and an organic extract of the particulate matter was evaluated in transplacentally exposed Syrian hamster fetal liver cells. The frequency of sister chromatid exchange (SCE) was determined on day 13 of gestation. The extract of diesel particulate matter caused a dose-dependent increase in the frequency of SCE with a doubling in the incidence above 320mg/kg. The diesel particulate matter and diesel exhaust emissions did not alter the frequency of SCE. The extract and particulate matter did cause a dose-dependent decrease in the mitotic activity of the fetal liver. The in utero SCE analysis was demonstrated to be a sensitive assay for determination of the genotoxic activity of a complex mixture in transplacentally exposed fetuses.
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Benzo[a]pyrene between 50 and 125 mg/kg administered maternally caused a dose-related increase in sister-chromatid exchange in fetal hamster liver cells. There was no difference on days 11, 13 and 15 of gestation in the sensitivity of fetal liver to benzo[a]pyrene.
Particulate matter was collected from the emissions of a diesel-powered engine and the organic components were extracted. The extract induced a dose-related increase in sister-chromatid exchanges in human lymphocytes with a potency of about one-fifth that of benzo[a]pyrene.
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Examination of intrafamilial contacts among the first degree relatives of 400 hanseniasis patients, revealed an additional 101 cases. Distribution pattern of disease types detected in the contacts, in relation to that found in the index cases, are analysed. An attempt has been made to evaluate the role of genetic factor in determining the type of hanseniasis in a patient.
Reports of acute nonlymphoblastic leukemia occurring after successful treatment of Hodgkin and non-Hodgkin lymphoma (NHL) are appearing with increasing frequency. Two years after completion of LSA2-L2 therapy for stage III, poorly differentiated lymphocytic lymphoma, a 16-year-old boy developed a preleukemic state characterized by a refractory macrocytic anemia with excess blasts, dyshematopoiesis, abnormal cluster:colony ratio on in vitro bone marrow culture, and acquired deficiencies of erythrocyte pyruvate kinase, triose phosphate isomerase, and adenylate kinase. Four months later acute myeloblastic leukemia was evident. The RNA index determined by flow cytofluorometry was increased. Four marker chromosomes were found and involved complex translocation of chromosomes 11 and 17 (t11;l17) in 100% of the cells, and chromosomes 4 (t4q;4) in 10% of the cells. A thorough literature search uncovered four other reports of acute nonlymphoblastic leukemia occurring in children treated for NHL and a total of 58 cases in the adult and pediatric age groups. Over 50% of the patients had AML, were mean over 50 years of age, and were treated with radiotherapy and chemotherapy. It is anticipated that additional cases of second malignancies will be reported in this population of patients whose outlook for the curability of the primary malignancy is 75%.
Irradiated Syrian hamster fetal cells (feeder layer) and rat-liver homogenate (S9 mix) were used to compare their capacity to metabolize 3 known promutagens/carcinogens; BaP, 3-MC and DMBA. DNA-damaging potential was determined by the induction of SCE in V79 target cells. The S9 mix (1/20th strength) was toxic to the target cells and reduced the mitotic index by half with an exposure time of 2.5 h. The feeder layer was not toxic to the target cells and, therefore, was included for the duration of the Expt. The test chemicals elicited a dose-response with both activating systems. At similar concentrations of the test chemicals, the cells grown on the feeder layer showed a greater number of SCEs as compared to those activated by the S9 mix.
Penile involvement was seen in 19.5% of 261 patients, aged 11 to 30 years, with tinea cruris. It was more common in patients under the age of 20 years (p less than 0.05). The increased incidence is probably related to the use of langota, a semiocclusive undergarment that may favor the growth of dermatophytes.
Age of onset of leprosy is merely a subjective information based upon the memory, intelligent appreciation and awareness of the patient and his relatives, in absence of a more reliable method. In the present study, a modification of the conventional method which we named "Complemented recall" method was adopted to determine the age of onset of 400 leprosy patients, in an attempt to collect a better approximate data.
Innate incapacity to elaborate a protective cellular immunity has been thought to underlie the evaluation of the disease process of lepromatous leprosy. Although both family and twin studies were suggestive of the involvement of some genetic factors, they have so far not been evaluated fully. Keeping this in view, the present study, conducted at the family level, was designed to evaluate the role of genetic factors in determining the type of leprosy in a patient.