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Biomedical subjects

D Banerjee

Publications and source records attributed to D Banerjee.

At least 235 records · Page 13Linked to original sources
PubMed1984

Biosynthesis of high density lipoprotein by chicken liver: conjugation of nascent lipids with apoprotein A1.

To study the assembly of newly synthesized lipids with apoprotein A1, we administered [2-3H]glycerol to young chickens and determined the hepatic intracellular sites of lipid synthesis and association of nascent lipids with apoprotein A1. [2-3H]glycerol was rapidly incorporated into hepatic lipids, reaching maximal levels at 5 min, and this preceded the appearance of lipid radioactivity in the plasma. The liver was fractionated into rough and smooth endoplasmic reticulum and Golgi cell fractions. The isolated cell fractions were further subfractionated into membrane and soluble (content) fractions by treatment with 0.1 M Na2CO3, pH 11.3. At various times, the lipid radioactivity was measured in each of the intracellular organelles, in immunoprecipitable apoprotein A1, and in materials that floated at buoyant densities similar to those of plasma lipoproteins. Maximal incorporation occurred at 1 min in the rough endoplasmic reticulum, at 3-5 min in the smooth endoplasmic reticulum, and at 5 min in the Golgi cell fractions. The majority (66-93%) of radioactive glycerol was incorporated into triglycerides with smaller (4-27%) amounts into phospholipids. About 80% of the lipid radioactivity in the endoplasmic reticulum and 70% of that in the Golgi cell fractions was in the membranes. The radioactive lipids in the content subfraction were distributed in various density classes with most nascent lipids floating at a density less than or equal to 1.063 g/ml. Apoprotein A1 from the Golgi apparatus, obtained by immunoprecipitation, contained sixfold more nascent lipids than did that from the endoplasmic reticulum. These data indicate that [2-3H]glycerol is quickly incorporated into lipids of the endoplasmic reticulum and the Golgi cell fractions, that most of the nascent lipids are conjugated with apoproteins A1 in the Golgi apparatus, and that very little association of nascent lipid to apoprotein A1 occurs in the endoplasmic reticulum.

Animals↗
PubMed1984

Endogenous avidin-binding activity in human lymphoid tissue.

Biotin-avidin systems can be used as an alternative to indirect antibody sandwich methods in the detection of T lymphocyte subsets in cryostat sections of human lymphoid tissue. Appreciable endogenous avidin binding activity (EABA) has been found, however, in human lymph nodes and tonsils. Such EABA can be a source of false positive staining when biotin-avidin detection systems are used to identify cells in cryostat sections. The finding that avidin binding cells may also contain endogenous peroxidase activity and are morphologically similar to histiocytes suggests that such cells may be of histiocytic lineage. EABA is not seen in intrafollicular "tingible body" macrophages, however, and only rarely in medullary sinus histiocytes. Thus further studies are necessary to identify the lineage of avidin binding cells in lymphoid tissues. EABA can be effectively blocked by treatment of cryostat sections with 1% avidin followed by 0.01% biotin before specific staining with biotinylated antibodies and avidin-peroxidase or avidin-fluorochrome conjugates.

Avidin↗
PubMed1983

Lymphomatoid granulomatosis involving the central nervous system: complication of a renal transplant with terminal monoclonal B-cell proliferation.

A 33-year-old man, an immunosuppressed renal allograft recipient, developed fever of unknown etiology, multiple pulmonary densities, space-occupying lesions in the liver, confusion, disorientation, and seizures with cerebral infarcts. At autopsy, changes classical of active lymphomatoid granulomatosis (LYG) were found in the brain but those studied in the lungs and liver were in the healing phase. In addition, one cerebral focus in the right temporo-occipital lobe showed a lymphomatous transformation. Immunofluorescence studies done on this focus showed monoclonal IgG-lambda cytoplasmic staining in the perivascular infiltrate. Immunoperoxidase studies confirmed the monoclonal nature of this focus but showed a polyclonal pattern in the other foci. This finding is discussed along with the relationship between LYG and lymphoma.

Adult↗
PubMed1983

Changes in the intracellular accumulation and distribution of metallothionein in rat liver and kidney during postnatal development.

Metallothionein (MT) bound to zinc and copper was detected in high concentration in fetal and newborn rat livers by a cadmium saturation method. The levels of both hepatic zinc and MT remained high for the first 14 days after birth and decreased to adult levels by 24 days of age. There was a direct linear relationship between hepatic metallothionein and zinc concentrations during the first 31 days after birth. The ratio of MT to zinc levels also decreased with age suggesting a rapid degradation of MT during postnatal development. Immunohistochemical localization of MT by peroxidase-antiperoxidase technique, using a specific antibody to MT, showed intense intranuclear staining for MT in fetal and newborn rat liver which persisted until Day 9. The nuclear MT staining decreased with age; at 11 days it was equal both in nucleus and cytoplasm and at 14 days, MT was localized mainly in the cytoplasm, similar to adult rat liver pattern. The intranuclear localization of MT in neonates could be considered as a typical fetal-neonatal morphological pattern and its subsequent presence in the cytoplasm, an adult pattern.

Aging↗
PubMed1983

Biosynthesis of high density lipoprotein by chicken liver: nature of nascent intracellular high density lipoprotein.

Young chickens were administered L-[(3)H]leucine and after 10 or 30 min the livers were removed and fractioned into rough (RER) and smooth (SER) endoplasmic reticulum fractions and into light, intermediate, and heavy golgo cell fractions. The labeled high density lipoprotein (HDL), contained within these intracellular organelles was isolated either by immunoprecipitation using rabbit antiserum to rooster HDL, or by ultracentrifugal glotation between densities 1.063 and 1.21 g/ml. The radioactive apoproteins of nascent HDL were analyzed by SDS PAGE and detected by fluorography. Analyses of radioactive apoproteins obtained by immunoprecipitation from the contents of the RER, the SER, and the three golgi complex fractions revealed only one apoprotein, A1. The C peptide present in serum HDL was not detected intracellularly. The radioactive apoprotein A1 which is present within the cisternae of the RER and the SER fractions failed to float, whereas apoprotein A1, present within the golgi apparatus, readily floated between densities 1.063 and 1.21 g/ml. The HDL particles, isolated by flotation from the golgi apparatus content, were further characterized by lipid and protein analyses and by electron microscopy. Golgi HDL particles have the same density as serum HDL. On a percentage basis, golgi HDL contains less protein and more phospholipids than does serum HDL. Morphologically, golgi HDL is different in appearance from serum HDL. It is more heterogeneous in size, with most of the particles ranging 8.3-25 nm in diameter. The spherical particles contain small membrane tails. Occasionally, a few disk-shaped bilayer structures are also found within the golgi apparatus. These studies show that the newly synthesized apoprotein A1, present within the RER and the SER cell fractions, is not fully complexed with lipid and that apoprotein A1 does not acquire sufficient lipid to float at the proper HDL density until it enters the golgi apparatus. The difference in chemical composition and the heterogeneous size of golgi HDL may be attributed to the different stages of HDL maturation.

Animals↗
PubMed1983

Day-case cataract surgery.

The results of 501 day-case cataract extractions are presented. This is a safe way to manage an operation for which there will be an increased demand. Only 13% of these patients stated that they would have preferred to stay in hospital after surgery.

Aged↗
PubMed1983

Segmental myofiber necrosis in myotonic dystrophy - An immunoperoxidase study of immunoglobulins in skeletal muscle.

Because serum immunoglobulin G levels are low in patients with myotonic dystrophy, it was hypothesized that it might be catabolized within abnormal muscle fibers. Accordingly, immunohistochemical stains for immunoglobulins were performed on muscle sections derived at biopsy or autopsy from patients with myotonic dystrophy, other forms of muscular dystrophy, nondystrophic muscle disease, or normal muscle. Positive staining for immunoglobulins was found only in necrotic segments of myofibers (in 7 of 19 dystrophic and 6 of 27 nondystrophic subjects), and it is believed that the staining was due to nonspecific diffusion. However, staining reactions distinguished between incipient necrosis and artifactual contraction bands and allowed us to study segmental myofiber necrosis, comparing its frequency in the various muscle diseases. Segmental myofiber necrosis was present in 4 of 16 cases of myotonic dystrophy. The relevance of this finding to the clinical and morphologic features of myotonic dystrophy is discussed.

Adolescent↗
PubMed1983

The effect of a MAO inhibitor on reserpine-induced secretion of catecholamines from the adrenal medulla of the rose-ringed parakeet.

The effect of MAO inhibitor on reserpine-induced release of catecholamines from the adrenal medulla of the rose-ringed parakeet was investigated in this biochemical, histochemical, and ultrastructural study. The MAO inhibitor provided some blockade of epinephrine secretion and was ineffective in blocking norepinephrine secretion. Differences between birds and mammals were noted, suggesting that different mechanisms of catecholamine release may be operating in the two classes.

Adrenal Medulla↗
PubMed1982

Studies on superoxide dismutase activities in virulent and avirulent strains of Agrobacterium tumefaciens and also in normal and crown gall tumor cells of Bryophyllum calycinum.

Superoxide dismutase activity in virulent strains of Agrobacterium tumefaciens was found to be higher than that in avirulent strains. Polyacrylamide gel electrophoresis revealed two isoenzymes in both these strains. These isoenzymes are suggested to be iron and manganese containing superoxide dismutases. Crown gall tumor cells of the plant Bryophyllum calycinum were found to have higher superoxide dismutase activity than the normal plant cells. Polyacrylamide gel electrophoresis revealed two isoenzymes in both normal and crown gall tumor cells. Advantages of the higher superoxide dismutase activities in respect of the survival of virulent strains of A. tumefaciens and crown gall tumor growth have been discussed.

Iron↗