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Biomedical subjects

D Banerjee

Publications and source records attributed to D Banerjee.

At least 253 records · Page 14Linked to original sources

Monocyte IgG-Fc receptors in myotonic dystrophy.

Myotonic dystrophy (MyD), an autosomal dominant neuromuscular disease with multisystem abnormalities, is associated with hypercatabolism of IgG. The hypercatabolism is not related to structural abnormalities of the IgG molecule in MyD but appears to be due to a derangement of the serum IgG concentration-fractional catabolic rate relationship. Since the catabolic pattern of IgG is governed by the Fc portion of the molecule, the possibility of Fc receptor dysfunction in MyD has been explored. We have observed that although MyD patients have normal numbers of Fc receptor bearing leucocytes in their peripheral blood, MyD monocytes express significantly (P less than 0.02) greater numbers of Fc receptors (47.9 +/- 21.2 X 10(3) receptors/monocyte) than do monocytes of healthy subjects (29.1 +/- 9.6 X 10(3) receptors/monocyte). The mean affinity constants of the Fc receptors was lower in the MyD group (1.5 +/- 0.7 X 10(8)/M) than the normal control group (2.4 +/- 0.9 X 10(8)/M) but this difference was not statistically significant. MyD monocytes showed a propensity to shed Fc receptors in culture at 37 degrees C whereas no significant shedding was observed with control monocytes. Thus MyD monocytes may shed Fc receptors at physiological temperatures but at the same time express more receptors per cell than normal monocytes. This suggests that MyD monocytes may have an abnormally high turn-over of Fc receptors.

Cells, Cultured↗

Studies on membrane ATPase activity and lipid level in vibrio el tor under normal and nitrofurantoin resistant conditions.

Nitrofurantoin resistance brought about decreased level of membrane bound ATPase activity in Vibrio el tor as compared to the normal strain while phospholipid as well as total lipid levels in the membrane fraction was increased. Mg++ was found to be the mose effective co-factor for ATPase. At higher concentrations of sodium and potassium ions, ATPase of normal and nitrofurantoin resistant Vibrio el tor responded quite differently. A soluble ATPase extract having low phospholipid content was found to be activated by the phospholipid extracts of Vibrio el tor, phosphatidyl ethanolamine, and also by phosphatidyl choline which is not a constituent of the membrane preparation of Vibrio el tor strains.

Adenosine Triphosphatases↗

Studies on superoxide dismutase activity and modulation of nitrofurantoin resistance by hyperbaric oxygen in Vibrio el tor.

Superoxide dismutase, purified from Vibrio el tor, was found to have a molecular weight of 40,000. The enzyme was insensitive to KCN and NaN3 but was completely inhibited by H2O2 suggesting it to be an iron containing enzyme. Besides its ability to counteract the bactericidal effect of hyperbaric oxygen, the purified enzyme could to some extent prevent the enhanced bactericidal effect of nitrofurantoin in the presence of hyperbaric oxygen.

Drug Resistance, Microbial↗

Mediastinal mass with acute leukemia. Myeloblastoma masquerading as lymphoblastic lymphoma.

Acute leukemia of myeloblastic or myelomonocytic type after non-Hodgkin's lymphoma is a recognized complication of radiotherapy or chemotherapy. However, a few reports suggest spontaneous development of, or coexistent, acute myeloblastic or myelomonocytic leukemia in patients with non-Hodgkin's lymphoma, unrelated to therapy. We studied a case initially interpreted as being lymphoblastic lymphoma with spontaneous acute leukemia, but subsequently shown by cytochemical and ultrastructural studies to be myeloblastoma. We reviewed the previously reported cases of non-Hodgkin's lymphoma with spontaneous myeloid leukemia in the light of our findings, and such cases may, in fact, represent myeloblastomas (granulocytic sarcomas) rather than non-Hodgkin's lymphoma.

Aged↗

The antibody-independent cytotoxic activity of normal circulating human leucocytes. II. Failure to demonstrate effector cell-target cell interaction and target cell specificity of the circulating cytotoxic-enhancing factor.

The naturally-occurring antibody-independent cellular cytotoxic activity (NOCC) of normal circulating human monocytes and neutrophils was investigated employing a number of erythrocytes and the K-562 cell line as target cells simultaneously. The identity of the effector cell(s) was shown to be dependent upon or be a function of the type of target cell selected for the assay system. A number of erythrocyte targets (rabbit, horse, sheep and ox erythrocytes) were lysed to varying degrees by neutrophils and monocytes and not by lymphocytes. Irrespective of the red blood cell (RBC) target, the effector monocyte invariably possessed receptors for both C'3 and the Fc of IgG. In contrast, the cytotoxic cells using the K-562 target cell were lymphocytes. Monocytes and neutrophils were inactive. The cytotoxic-enhancing activity in normal human serum exhibits specific and non-specific properties which suggests that more than one factor is involved. With respect to the monocyte cytotoxic cells, only the rabbit erythrocytes could totally absorb the serum factor in a specific fashion. Absorption of the serum with horse, sheep or ox erythrocytes resulted in a significant loss of potentiating activity with respect to all of the erythrocyte targets but a more marked loss of activity using the absorbing erythrocytes as targets. With respect to the polymorphonuclear leucocyte effector cells, only the rabbit RBC were capable of specifically absorbing out the cytotoxic-enhancing factor present in the normal human serum. Absorption of the serum with sheep, horse or ox RBC resulted in total cross-absorption of the enhancing factor. Chicken and human RBC, which do not serve as targets for the NOCC assay, could not absorb out the cytotoxic-enhancing factor with respect to any of the target erythrocytes. The composition of the soluble serum factor(s) is under current investigation but it is not an immunoglobulin since pure serum albumin can substitute for normal serum in the NOCC assay. The mechanism of erythrocyte lysis by the cytotoxic monocyte was investigated. Mononuclear cells were incubated with target cell monolayers and with target cells under optimal rosetting conditions. No interaction between the effector and target cells could be detected. The monocytes did not adhere to the target cell monolayer nor did they form rosettes with the target cells. Thus, the results fail to corroborate or support the assumption that the cytotoxic activity of the monocyte is dependent upon conventionally-detectable receptors. Erythrophagocytosis was not observed to any significant degree under the assay conditions used. Therefore, the nature of the interaction between the cytotoxic monocyte and the erythroid target cell which results in lysis of the target cell remains to be elucidated.

Cell Line↗

The antibody-independent cytotoxic activity of normal circulating human leucocytes. I. Lysis of target cells by monocytes and neutrophils in a non-phagocytic pathway.

Normally circulating human leucocytes were found to consistently lyse rabbit erythrocyte (RRBC) target cells within 24 hr in culture. The reaction is referred to as the naturally-occurring cell-mediated cytotoxic, or NOCC, reaction. Characteristics of this cytotoxic reaction are as follows. (i) The cytotoxic reaction described here can be distinguished from the antibody-dependent cellular cytotoxic (ADCC) reaction as conventional Fc receptors do not appear to play a role. Although the cytotoxic reaction occurs optimally in medium fortified with normal human serum to a final concentration of 1%, neither antibodies nor immunoglobulins in general appear to play a role. Agamma human serum or purified human serum albumin without detectable immunoglobulins are as capable of facilitating and sustaining the NOCC cytotoxic reaction as is normal human serum. Furthermore, foetal calf serum, which promotes the ADCC cytotoxic reaction, inhibits the NOCC cytotoxic reaction. (ii) The NOCC reaction is not a phagocytic one as phagocytosis of the RRBC could not be detected during the culture period. (iii) Monocytes and neutrophils, but not lymphocytes, are capable of lysing the target cells in the NOCC reaction. The effector mononuclear cell is a monocyte with receptors for Fc and C'3. (iv) The NOCC cytotoxic reaction is dependent upon direct effector cell--target cell contact and not upon soluble mediators secreted by the effector cells since third-party bystander erythrocytes are not lysed in the presence of rabbit erythrocyte target cells and human mononuclear cells. Supernatants from lysed RRBC target cells could not lyse fresh RRBC. It is concluded that the NOCC cytotoxic reaction utilizing rabbit erythrocytes as target cells permits the identification of cytotoxic subclasses of monocytes and neutrophils.

Antibody-Dependent Cell Cytotoxicity↗

Day-case cataract surgery.

This is a report of prospective trial to compare day-case and inpatient surgery for senile cataract. In this district, cataract extraction is usually delayed until bilateral surgery is warranted. Both eyes are then operated upon a week or so apart. Such patients are ideal for comparing the results of day-case and in-patient management, since if one eye is done by each method, there is a perfect match for age, sex, general medical health, and domestic circumstances. During a period of 27 months, 138 patients aged 50 years or over were included in this trial. Five more patients were dropped from the trial and 78 other cataract operations were performed outside the trial for various reasons. For those included in the trial, the eye with the worse vision was operated upon first and patients were randomly allocated to have this eye managed as a day-case or an inpatient. All these operations were performed by the same surgeon (D.B.). Details of events during the 48 hours after surgery were kept (M.J.T.) separate from the hospital records used for follow-up (R.M.I.) and refraction (R.K.T.), which were therefore done without knowledge of how each eye had been managed. Visual acuity and intraocular pressure were recorded 2 to 3 months and one year after operation for those in the trial. Visual acuity alone was recorded at 2 to 3 months for those not in the trial. It is concluded that provided the patients are carefully selected, the advantages of day-case surgery outweigh the disadvantages both for patient management and considerations of economy.

Aged↗

Direct splenocaval shunt for selective decompression of portal hypertension in children.

A new operation for selective decompression of portal hypertension in children with diminutive splenic veins is desired. The operation, direct splenocaval shunt (S-D-SCS), produces transplenic decompression of gastric-esophageal varices without interfering with the existing portal flow status in any significant measure. The proximal free end of the inferior vena cava (IVC) is joined to the side of the splenic vein, which is ligated on the hepatic side of the anastomosis. Addition of partial gastric devascularization completes the operation. Technically the operation is simple and easily executable. Because the IVC is utilized in creation of the shunt, anastomoses as large as 1.72 +/- 0.45 cm in diameter are obtained with splenic veins of less than 1 cm in diameter. S-D-SCS was performed in 10 children with a mean age of 9.25 +/- 3.36 years and a mean splenic vein size of 8.2 +/- 2.25 mm in diameter. Shunt thrombosis occurred in one patient who died. Nine patients survived the operation and obtained class A surgical results over a follow-up period of 7 to 12 months. None rebled, developed postshunt encephalopathy (PSE), or manifested laboratory evidences of protein intolerance. Insignificant alterations were brought about in liver blood flow (EHBF) and sinusoidal pressure (CSP); portal blood flow to the liver was maintained; and liver function tests were preserved at preoperative levels. The surgical results were superior to those following mesentericocaval and portacaval shunts in our earlier series of children with comparable mean age, body weight, and postoperative interval when studied functionally. About 30% of all of the shunt patients died of liver failure within weeks or months after the operations, and an additional 30% of the patients developed clinically significant PSE over variable periods of follow-up. These high mortality and morbidity rates were preceded by significant reductions in EHBF and CSP and concomitant precipitation of liver function abnormalities.

Adolescent↗

Leukemic reticuloendotheliosis: polyclonal surface immunoglobulin on "hairy" cells.

The cytochemistry, surface markers and functional properties of purified mononuclear cells obtained from the peripheral blood and spleen of a patient with leukemic reticuloendotheliosis were studied. Nonspecific esterase activity, a monocyte marker, was demonstrable in 83% of the peripheral blood mononuclear cells and 84% of the splenic mononuclear cells. Rosetting techniques failed to detect T or B lymphocyte surface markers on the majority of the cells. Direct immunofluorescence revealed capped, noncytophilic surface immunoglobulin on the cells with all immunoglobulin classes being detectable. Since noncapping conditions ahd been used during immunofluorescence staining, the observed caps were attributed to in vivo binding of autoantibodies to the "hairy" cells. This conclusion was supported by the demonstration of susceptibility of the "hairy" cells to lysis mediated by normal allogeneic lymphocytes. It is postulated that the "hairy" cells in this patient are leukemic monocytes which bear autoantibodies directed against leukemia associated antigens.

Antibodies, Neoplasm↗

In vivo effect of colchicine on hepatic protein synthesis and on the conversion of proalbumin to serum albumin.

Treatment of rats with 0.5-25 mumol/100 g body weight of colchicine for 1 h or more caused an inhibition of hepatic protein synthesis. This effect was not seen if animals were exposed to colchicine for less than 1 h. The delayed inhibition of protein synthesis affected both secretory and nonsecretory proteins. Treatment with colchicine (15 mumol/100 g) for 1 h or more caused the RNA content of membrane-bound polysomes to fall but did not change the polysomal profile of this fraction. By contrast, the total RNA content in the free polysome cell fraction was increased, and this was due to the presence of more ribosomal monomers and dimers. Electron microscope examination of the livers from rats treated for 3 h with colchicine showed an accumulation of secretory vesicles within the hepatocytes and a general distention of the endoplasmic reticulum. Administration of radioactive L-leucine to the rats led to an incorporation of radioactivity into two forms of intracellular albumin which were precipitable with antiserum to rat serum albumin but which were separable by diethylaminoethyl-cellulose chromatography. One form has arginine at the amino-terminal position and is proalbumin, and the other form, which more closely resembles serum albumin chromatographically, has glutamic acid at its amino terminus. Only proalbumin was found in rough and smooth endoplasmic reticulum fractions and in a Golgi cell fraction wich corresponds morphologically to mostly empty and partially filled secretory vesicles. However, in other Golgi cell fractions which were filled with secretory products, both radioactive proalbumin and serum albumin were found. This indicates that proalbumin is converted to serum albumin in these secretory vesicles just before exocytosis. Colchicine delayed the discharge of radioactive albumin from these filled secretory vesicles and caused an accumulation of both proalbumin and serum albumin within these cell fractions.

Animals↗

Effect of local anesthetics on plasma protein secretion by rat hepatocytes.

The effects of some local anesthetics on plasma protein secretion by rat liver slices have been studied and have been compared with those of colchicine. Rat liver slices were pulse-labelled with L-[14C]leucine for 9 min at 37 degrees C, collected on filter paper, washed with non-radioactive leucine and reincubated in the presence or absence of the drug to be tested. The radioactive plasma proteins produced were obtained by immunoprecipitation from either the chase medium or from the washed slices. Chlorpromazine, (3.10(-5) M), dibucaine (10(-5) M), lidocaine (10(-3) M) and procaine (5.10(-5) M) inhibited both the synthesis and secretion of plasma protein but did not affect the uptake of L-leucine into the slices nor the incorporation of phosphate into intracellular nucleotide phosphates or into phospholipids. The inhibition of secretion elicited by these drugs is probably not due to the inhibition of protein synthesis since cycloheximide, when added to the chase medium at a concentration which completely inhibits protein synthesis, did not inhibit plasma protein secretion, while cycloheximide plus procaine did inhibit secretion and also caused a retention of non-secreted plasma proteins within the slices. Unlike colchicine, however, procaine did not cause the retained plasma proteins to accumulate in Golgi-derived secretory vesicles, but showed a more general effect causing a distribution among several cell fractions.

Anesthetics, Local↗

The in vivo effect of colchicine on the addition of galactose and sialic acid to rat hepatic serum glycoproteins.

Colchicine inhibits the secretion of plasma protein by rat hepatocytes and causes their intracellular accumulation in Golgi-derived secretory vesicles. This study examines whether colchicine affects secretion before or after galactose and sialic acid have been added to the secretory glycoproteins. D-[G-3H] Galactose was injected into rats and was found to be incorporated into serum glycoproteins contained within Golgi-derived secretory vesicles. The administration of colchicine (25 mumol/100 g, body weight), immediately before the injection of D-[G-3H] galactose, caused an increase in radioactivity of the serum glycoproteins in these cell fractions. D-[G-3H] Glucosamine was incorporated into serum glycoproteins contained within the rough and smooth endoplasmic reticulum and the Golgi cell fractions; however, its incorporation into the sialic acid moieties of these proteins only occurred in Golgi-derived cell fractions. Colchicine administration resulted in an increased incorporation of D-[G-3H] glucosamine into the sialic acid residues of serum glycoproteins contained within the Golgi cell fractions. These data indicate that colchicine inhibits secretion of serum proteins by rat liver after the addition of galactose and sialic acid to the secretory proteins has taken place.

Animals↗

Immunocompetent cells in patients with malignant disease. I. The lack of naturally occurring killer cell activity in the unfractionated circulating lymphocytes from patients with chronic lymphocytic leukemia (CLL).

The unfractionated, buffy coat cells of patients with chronic lymphocytic leukemia (CLL) were compared with their counterpart cells from normal volunteers for the capacity to lyse chromium-labeled xenogeneic target cells in vitro. Whereas killer cells were consistently detected in the circulation of normal individuals, no significant numbers of killer cells could be detected in the circulation of CLL patients. It is concluded that either these cells are not present in the circulation of CLL patients or that they are present in small numbers undetectable by this procedure. The possibility that killer cells in CLL patients are diluted by the much larger number of immunoincompetent cells has been ruled out.

Cytotoxicity Tests, Immunologic↗