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Biomedical subjects

M K Basu

Publications and source records attributed to M K Basu.

At least 73 records · Page 4Linked to original sources
PubMed1984

Characteristics of I and i antigen receptors on the membrane of erythrocytes in sickle cell anemia.

In this study we employed two approaches in attempts to explain the increased expression of I and i antigens on the membrane surface of SS erythrocytes: immunoelectron microscopy and measurements of antigen-antibody affinity. AA and SS erythrocytes were first reacted with anti-I or anti-i antisera, and then with ferritin-conjugated anti-human IgM. With both antibodies, proportions of cells labeled and ferritin-cluster density on labeled cells were greater for SS erythrocytes at a high level of significance. Studies on the temperature dependence of agglutination by anti-I provided the association constants of agglutination, which were uniformly greater for SS erythrocytes. I and i antigen determinants are carried principally on band 3, the major transmembrane protein of the erythrocyte membrane. Therefore, for SS erythrocytes, the increased I (and i) antigen density and the increased association constant of agglutination by anti-I very likely both reflect the same phenomenon: a relatively greater exposure of I (and i) antigen determinant sites at the membrane surface. Any deviation from normal at the exterior surface of the erythrocyte membrane deserves to be suspect for potential pathogenicity, because this is the cell's region of intimate contact with other elements of the circulation. In addition to enhancing susceptibility of SS erythrocytes to cold agglutinins, an altered exposure of band 3 at the membrane outer surface has the potential for accelerating recognition and removal of SS erythrocytes from the circulation by mononuclear phagocytes.

Agglutination Tests↗
PubMed1983

Primary extranodal lymphoma of the oral cavity: an immunohistochemical study.

Eleven cases of primary extranodal lymphoma occurring within the oral cavity were studied using an immunoperoxidase technique on formalin fixed paraffin embedded tissue to detect immunoglobulin, J chain, lysozyme and alpha 1 antitrypsin. On the basis of immunoglobulin and J chain content, the 11 cases fell into 4 groups. Staining for lysozyme and alpha 1 antitrypsin revealed a large variation in the staining intensity and numbers of reactive histiocytes between cases, although no positive staining of lymphoma cells was found. The results indicate that 64 per cent of the lesions were of B lymphocyte origin with no proven cases of true histiocytic lymphoma and are consistent with similar studies of nodal lesions.

Adult↗
PubMed1983

Benign lymphoepithelial lesion in a patient with Sjögren's disease and an IgG paraprotein.

Clinical and laboratory investigations were performed on a patient presenting with xerostomia and swelling of the parotid gland. Lymphoid infiltration of the salivary glands (parotid and labial) and paraproteinaemia were found. Immunoperoxidase studies of labial and parotid glands revealed that local immunoglobulin synthesis was essentially polyclonal although monoclonal staining of Russell bodies within the labial tissue suggested that at least some of the serum paraprotein was being synthesised locally. The implications of these findings are discussed in terms of diagnosis and treatment.

Diagnosis, Differential↗
PubMed1982

Kaolin powder as a fungal carrier.

Kaolin powder may be used to carry and preserve an Aspergillus sp. for at least 90 days without contamination and with retention of its activity in softening and upgrading barky jute.

Journal Article↗
PubMed1982

Oral tonsils: an immunoperoxidase study.

Tissue morphometry and the distribution of cells containing immunoglobulin (Ig), J chain and secretory component (SC) were studied in eight oral tonsils. Quantitative immunohistochemistry revealed that IgG-containing cells predominated in all lymphoid compartments (follicles, extrafollicular areas and reticular epithelium) and that the IgG:IgA:IgM class ratios of the overall tonsillar immunocyte population were 13:8:2. Cells containing IgD and IgE were rare. IgG immunocytes showed no significant localisation within a given lymphoid compartment, whereas IgA cells were found predominantly in extrafollicular areas, especially adjacent to surface epithelium, and IgM cells were in follicles. J chain was present within IgM and some IgA cells. Tonsillar crypt and surface epithelium was negative for SC, suggesting that these structures are not directly involved in local mucosal immunity.

Humans↗
PubMed1982

Role of membrane lipids in cold agglutination of human erythrocytes.

The membrane lipid fluidity of normal human erythrocytes was modified by enrichment and depletion in cholesterol, and the expression of I and SP1 antigens was assayed by quantitative hemagglutination from 4 degrees to 24 degrees C by use of a continuous flow system. Below 16 degrees--18 degrees C, cholesterol enrichment increased and cholesterol depletion decreased percent agglutination. As temperatures approached approximately 18 degrees--20 degrees C, differences in agglutination between modified and unmodified erythrocytes became insignificant despite marked differences in lipid fluidity at that temperature. Thus, fluidity changes alone cannot be responsible for the effect of membrane cholesterol on cold agglutination. In an additional study, the temperature dependence of a relative equilibrium association constant, estimated by probit analysis of percent agglutination at various antisera concentrations, was biphasic with a sharp break at 16 degrees C. Our studies are consistent with the hypothesis that I and Sp1 antigens preferentially partition into a lipid domain that forms during lateral phase separation of membrane lipid developing at low temperature. A resulting increase in antigen density would then become responsible for augmented agglutination by specific antibody.

Cholesterol↗
PubMed1980

Surface properties of membrane systems: interaction of electrolyte and lipid with Ca2+ ionophores.

When spread from organic solvents onto electrolyte solutions, the Ca2+ ionophores A23187 (I) and X537A (II) formed films with relatively high surface pressures potentials. Ionophores I had collapse pressures between 16 and 19 dynes/cm and nearly equal surface activity on distilled water and on 1000 mEq of either sodium chloride or calcium chloride. Film pressure did not reveal appreciable ion selectivity. However, the surface potential of I on calcium chloride solution was higher than that on sodium chloride, and the potential difference, delta(deltaV), of 40 mv was independent of the electrolyte concentration. In contrast, the ion selectivity of II was dependent on the electrolyte concentrations since the delta(deltaV) value between calcium chloride and sodium chloride was maximal (130 mv) on 1000 mEq and negligible on 500- and 2000-mEq salt solutions. The isotherms of phospholipid-ionophore films were markedly different from those of the individual components, although they revealed ionophore characteristics at low film pressures and phospholipid behavior at high film pressures. The magnitude of the surface potential indicated that dipalmitoyl phosphatidylcholine enhanced, whereas mitochondrial lipid and cardiolipin reduced, the preference of the two ionophores for Ca2+ over Na+. Since the ion selectivity was manifested most at both high electrolyte and high lecithin concentrations, the ionophore probably prefers the low dielectric constant of neutral lipid membranes to complex with the selected cation.

Animals↗
PubMed1979

Surface properties of membrane systems: interaction of ketamine with monomolecular films of ganliosides and mitochondrial lipids.

Ketamine solutions did not form a film (pi=0) but had an appreciable surface potential (delta V=500 mv), indicating a significant array of +/- oriented charge dipoles at the air-water interface, as opposed to calcium chloride solutions whose delta V was zero. The delta V values of ganglioside films spread on the aqueous phase varied in the order water less than sodium chloride less than calcium chloride less than ketamine hydrochloride. At equivalent concentrations, calcium chloride was 500 times as effective as sodium chloride, and ketamine at the clinical concentrations of 10-20 microgram/ml (36-72 micrometer) was 6000 times as effective as calcium chloride in raising the surface potential of gangliosides; the delta V effect with mitochondrial lipid was in the reverse order; water less than sodium chloride = ketamine hydrochloride less than calcium chloride. This calcium-ketamine inversion indicates a unique specificity of ketamine for gangliosides. Since ketamine acts on the brain and did not affect mitochondrial respiration, the surface potential data suggest that part of the mechanism of action of ketamine could be its interaction with synaptic surfaces and, specifically, with the sialic acid of gangliosides and/or glycoproteins present on the synaptic membrane surface.

Absorption↗
PubMed1979

Warty dyskeratoma. A note concerning its occurrence on the oral mucosa, and its possible pathogenesis.

A case of warty dyskeratoma occurring in the oral mucosa is presented. Indirect immunofluorescence tests using the patient's serum showed the presence of IgG class antibodies reactive with intercellular material of guinea-pig lip mucosa and IgM class antinuclear antibodies. The patient did not have any clinical histopathological, haematological or serological evidence of other autoimmune disease.

Darier Disease↗
PubMed1979

Immune responsiveness and oral immunization.

The effects on the immune response of daily feeding of 30 mg of human serum albumin to rats have been studied. Feeding for periods of 17-20 days consistently resulted in a specific systemic hyporesponsiveness evident on subsequent parenteral immunogen challenge. Local secretory sites such as the major salivary glands were not made hyporesponsive as evidenced by the salivary antibody titres and the enumeration of glandular plaque-forming cells. The levels and classes of antibodies present in the secretions and sera were identified by passive haemagglutination, and a sensitive red-cell-linked antigen-antiglobulin reaction. By the use of radioimmunoassay and haemagglutination inhibition assays it was possible to quantitate the amount of antigen appearing in the circulation at varying times after feeding. It was shown in the use of oesophagectomised rats that absorption of small amounts of intact protein occurs from undefined sites in the oral cavity. Attempts were made to transfer the specific systemic hyporesponsiveness to syngeneic animals using spleen cell and serum transfers.

Administration, Oral↗
PubMed1978

Effect of serum albumin on dynamic force-area curve of dipalmitoyl lecithin.

In line with previous findings at 25 degrees C, solutions of serum albumin in the subphase stabilized the surface activity of DPL spread films at 25 degrees C as well as 37 degrees C. In contrast, films adsorbed from mixtures of DPL and albumin exhibitied a marked inhibitory action of the albumin on DPL activity. The inhibitory effect increased with the relative protein concentration but, with albumin/DPL ratios smaller than 2, the DPL activity was regained gradually with cycling. With larger albumin/DPE negative effect of albumin was counteracted by higher temperatures (37 degrees C vs 25 degress C) and modest cholesterol concentrations; with greater cholesterol concentrations the known inhibitory effect of cholesterol prevailed. The inhibitory effect of albumin was potentiated by humidity; saturation of the atmosphere with water vapor at 37 degrees C abolished the DPL character of DPL-RSA mixtures and prevented its return (zero surface tension) upon reversal of the atmosphere from saturated water vapor to dry air. The data are important in the interpretation of the surface activity of pulmonary washings and other pulmonary extracts.

Adsorption↗