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Biomedical subjects

P Chandra

Publications and source records attributed to P Chandra.

At least 109 records · Page 6Linked to original sources
PubMed1980

Unilateral analgesia following epidural and subarachnoid block.

A case of unintentional unilateral analgesia following both epidural and subarachnoid block is presented. It is suggested that the presence of an anomalous congenital midline diffusion barrier in both the epidural and subarachnoid spaces could explain this phenomenon.

Adult↗
PubMed1980

Immune responses in pulmonary lymph of sheep after intrabronchial administration of heterologous erythrocytes.

The response of the lower respiratory tract to intrabronchial administration of horse red blood cells (HRBC) was studied in sheep by continuous monitoring of efferent lymph issuing from the regional caudal mediastinal lymph node. The immune response was assessed by enumerating direct and indirect plaque-forming cells (PFC) in pulmonary lymph, bronchoalveolar lavage, and blood as a function of time after immunization. Within 3 days, PFC began to appear in pulmonary lymph, reaching a peak between Days 5 and 7. During the primary immune response, PFC were not detected in either bronchoalveolar lavage or blood. A second antigenic challenge resulted in a rapid, marked increase in lymph PFC, predominantly of the indirect type. Plaque-forming cells in lung lavage and blood, although observed after a secondary challenge, were inconsistent, particularly with the lower dosages of antigen. Within the narrow range of antigen dosage used, there was a clear dose-response relationship for a lymph-borne PFC during both the primary and secondary immune response. As with PFC, a high titer of antibody in lymph preceded its appearance in serum. The results indicated that monitoring efferent lung lymph can be a very sensitive and reproducible method to assess various aspects of pulmonary immune responses. In contrast, bronchoalveolar lavage elements did not effectively reflect the status of immune reactivity in the lower respiratory tract.

Animals↗
PubMed1980

Recovery of thebaine and cryptopine from Indian opium.

The thebaine content of the opium collected in the Madhya Pradesh region of India has been estimated and reported to range from 1.5 to 2.0 per cent. A technological process for the recovery of thebaine from the mother liquor remaining after the separation of natural codeine in the Government Opium and Alkaloid Works, Neemuch, has been developed in the laboratory and stepped up to an industrial scale. A method for the recovery to thebaine from the waste slaked-lime residues obtained from crude alkaloid cake mother liquor in the Government Opium and Alkaloid Works at Ghazipur has been worked out and the technical details of the process described. The recovery of thebaine would help to increase the production of codeine, and thebaine can also be used as a raw material for the manufacture of other drugs. Cryptopine has also been recovered from the mother liquor after the separation of thebaine.

Alkaloids↗
PubMed1980

Cyclic oscillation of blood neutrophils in a patient with multiple myeloma.

A patient with multiple myeloma developed periodic blood neutropenia (periodicity of 15-25 days) after 3 yr of intermittent treatment with cytotoxic agents. Peaks of serum colony-stimulating activity (CSA) level coincided with valleys of blood neutrophils. Fraction of marrow neutrophils in the multiplicative pool was high during blood neutrophil valleys and low during neutrophil peaks. In contrast, the maturation storage pool exhibited the reverse pattern. An increased fraction of marrow neutrophilic cells in the multiplicative pool was in active proliferation during a blood neutrophil valley and a decreased fraction during a blood neutrophil peak. These findings suggest that the marrow granulopoiesis was regulated through CSA. The defect causing the periodicity was probably related to the reduced number of neutrophils in the marrow maturation storage pool, which in turn may be related to a reduced and/or defective granulocytic stem cell pool size consequent to the long-term administration of cytotoxic drugs and/or infiltration of the marrow by myeloma cells.

Agranulocytosis↗
PubMed1980

Distribution of T and B lymphocytes in blood and lymphoid tissues of fetal and adult sleep.

Distributions of B and T lymphocytes in blood and various lymphoid tissues of clinically normal adult and fetal sheep were studied. The B and T lymphocytes were identified in enriched preparations of blood lymphocytes and cell suspensions of solid tissues. The T lymphocytes were quantitated by indirect immunofluorescence, using rabbit antisera to sheep thymus cells. The B lymphocytes were identified by direct immunofluorescence, using rabbit antisera to sheep immunoglobulin.

Animals↗
PubMed1979

Experience with sonography as an adjunct to amniocentesis for prenatal diagnosis of fetal genetic disorders.

This report summarized our experience with a consecutive series of 800 women referred for midtrimester amniocentesis for prenatal diagnosis of a fetal genetic abnormality. The results are compared before and after introduction of sonography immediately prior to the tap as a routine adjunct of the procedure. Following use of sonography there was a statistically significant reduction in the frequency of bloody taps, and an increase in the proportion of successful and informative initial taps. Moreover, in many instances sonography provided information useful for identification of fetal abnormalities or for management of pregnancy. These findings support the recommendation that examination by sonography should be utilized routinely as an adjunct to amniocentesis, despite the uncertainities relating to possible long-term adverse effects of intrauterine exposure to ultrasound.

Amniocentesis↗
PubMed1979

Proliferation of human lymphocytes in culutre: determination by measurement of nuclear volume and cell number.

Proliferation of stimulated human lymphocytes was studied in cultures by determining cell counts and nuclear volume enlargement. DNA content and the nuclear volume increase before the cell divides. Volume-frequency curves were obtained of unstimulated and phytohemagglutinin (PHA) stimulated lymphocytes on 0, 3, 6 and 9 days of cultures with the Coulter Counter H4 system. As the number of lymphocytes in the cultures transformed and enlarged in volume, the area under the volume-frequency curve increased proportionately. The fraction of transforming cells was determined by comparing the area under the curve of the unstimulated and the stimulated lymphocytes. This method provides both the fraction of cells transformed and the increment of the number of cells in the culture and is therefore a better indicator of cell proliferation than the commonly used isotope-labeled thymidine uptake method which monitors the fraction of the cells in DNA synthesis phase only.

Cell Count↗
PubMed1979

Purification and biochemical characterization of a virus-specific reverse transcriptase from human osteosarcoma tissue.

A RNA-dependent DNA polymerase (RTase) was purified from human osteosarcoma tissue by successive column chromatography of the microsomal fraction on DEAE-cellulose (DE-23 and DE-52) and phosphocellulose. The purified enzyme has a molecular weight of about 68,000, a pH optimum of 8.1, a Mg2+ optimum of 0.8 mM, Mn2+ optimum of 1.0 mM and a KCl optimum of 60 mM. The enzyme transcribes (rA)n . (dT)12, (rC)n . (dG)12-18 and (2-O-methyl C)n . (dG)18, but is unable to transcribe (dA)n . (dT)10. The enzyme has no catalytic activity in the presence of oligodeoxynucleotide initiators alone, indicating the absence of terminal deoxynucleotidyl transferase. The purified enzyme is able to transcribe the heteropolymeric regions of a 70S RNA from R(Mu)LV. The presented data support the presence of a RNA-dependent DNA polymerase in human osteosarcoma tissue with biochemical properties, resembling those of C-type RNA tumor viruses.

Adolescent↗
PubMed1979

Correlation of total body potassium and leukemic cell mass in patients with chronic lymphocytic leukemia.

Total body leukemic mass in patients with chronic lymphocytic leukemia (CLL) was measured by quantitation of total body potassium (TBK) with a whole-body counter. In addition, the predicted normal total body potassium (Kp) for each patient was calculated from an empirically derived relationship involving height, weight, age, and sex. Both the absolute TBK and the relative excess of total body potassium (TBK/Kp) were related to the stage of disease. Patients in the early stages of CLL were found to have lower TBK and TBK Kp than patients in the late stages of disease. Both of these parameters increased with the successively advanced stages of the disease. The clinically monitored reduction of leukemic cell mass following therapy was accompanied by reductions in TBK and TBK/Kp. Data presented support the notion that TBK/Kp is a useful indicator of the total body leukemic mass. Furthermore, the results of these studies quantitatively validate the proposed clinical staging system for CLL. Quantitation of TBK by a whole-body counter is an accurate and noninvasive procedure and does not require administration of isotopes.

Humans↗
PubMed1979

[Clinical trials with mercapto polycytidylic acid in the treatment of acute childhood leukemia (author's transl)].

Mercapto Polycytidylic acid (MPC) is a potent inhibitor of oncornaviral reverse transcriptase. The fact that this enzyme has been found in human leukemic cells, has let to the clinical trials of MPC in the treatment of childhood acute leukemia. This report discribes the first pilot clinical trial on 23 patients. The results are encouraging, and have let to a second pilot study including other clinical centers on the clinical efficacy of MPC in the treatment of leukemia.

Acute Disease↗