Modulation of mouse anti-trinitrophenyl plaque-forming cell affinity by adjuvants or lectins

The efffects of several kinds of adjuvants or lectins, such as Corynebacterium parvum, dextran, poly AU, poly IC, dibutyryl cAMP, concanavalin A (Con A), phytohemagglutinin (PHA) and pokeweed mitogen (PWM) on anti-trinitrophenyl (TNP) direct plaque-forming cells (PFC) in the spleen of mice and the affinity of antibodies produced by these PFC were examined. The numbers of anti-TNP PFC in the spleens of mice which had been injected with C. parvum 7 days in advance were greater than those in controls after immunization with TNP-coupled heterologous erythrocytes, while the affinity of antibodies released by these PFC. Copolymers of nucleotides, poly AU and poly IC, were capable of enhancing splenic anti-TNP PFC responses, but showed almost no altering of PFC affinity. Dibutyryl cAMP did not have any effect on this system. Con A had potencies to both augment the number of anti-TNP PFC and heighten the PFC affinity, while PHA seemed to lack these potencies. Injection of PWM in the presence of antigen increased the number of anti-TNP PFC and heightened slightly the PFC affinity. These results indicate that the heightening of the affinity at the cellular level is regulated in ways different from the augmenting effects on the number of anti-TNP PFC by adjuvants or lectins. These results are discussed in the light of the mode of action of the substances used.

Dissolution behavior and bioavailability of phenytoin from a ground mixture with microcrystalline cellulose

The ground mixture of phenytoin and microcrystalline cellulose was prepared by grinding in a vibrational ball mill. The X-ray diffraction patterns indicated the amorphous nature of the ground mixture. Comparative studies were made concerning the in vitro dissolution and in vivo absorption of fine phenytoin powder, phenytoin sodium powder, and the ground mixture. The ground mixture showed a greater dissolution rate than the fine powder and attained supersaturation in the pharmacopeial disintegration media at pH 1.2 and 7.4. In vivo absorption studies of each preparation were carried out in five subjects, using a crossover design, by measuring the urinary excretion rate of a main metabolite, 5-(p-hydroxyphenyl)-5-phenylhydantoin. The blood levels of phenytoin and the corresponding urinary excretion patterns of the metabolite were determined in two subjects. The ground mixtures significantly improved the bioavailability of phenytoin. The drug was completely and rapidly absorbed after oral administration of the ground mixture. The vibrational ball milling technique for a poorly water-soluble drug with microcrystalline cellulose provides a promising way of improving the in vivo drug absorption.

L-Rhamnose dehydrogenase of pullularia pullulans

Growth of Pullularia pullulans on L-rhamnose induces formation of L-rhamnofuranose dehydrogenase, whichreversibly converts L-rhamnofuranose to L-rhamnono-gamma-lactone with the concomitant reduction of NAD, but not of NADP. The dehydrogenase was purified 100-fold by MnCl(2) treatment...

Controlled drug permeation I: controlled release of butamben through silicone membrane by complexation

The effects of caffeine, beta-cyclodextrin, and povidone on the permeation behavior of butamben from saturated solutions in these complexing agents through a dimethyl polysiloxane membrane were investigated at 30 degrees. In all systems, these agents increased the rate of release over the plain saturated drug solution. The effect was more pronounced with caffeine and beta-cyclodextrin than with povidone. Interpretation of these results with the aid of solubility data for the corresponding systems led to the following generalization. For a fixed total (free and complexed) amount of drug available for release, sustained release is associated with systems containing more stable complexes. The practical value of this approach to the controlled release of drug is discussed.

Studies on the interaction between coxsackievirus A9 and HeLa cells. I. Plaque-forming ability of coxsackievirus A9 in HeLa cell cultures

Most of the coxsackievirus A9 (CA 9 virus) including the prototype strain formed plaques in HeLa cell monolayers under agar overlay, although they showed little or no cytopathogenicity under fluid medium. These viruses were isolated or passaged in primary cynomolgus monkey kidney (MK) cell cultures, and the infectivity of any strain in terms of plaque-forming units was much higher in MK cells than in HeLa cells, even after plaque purification of the virus in HeLa cell cultures. CA 9 virus contained in the original throat swabs as well as some clones obtained by plaque purification in MK cells failed to form plaques in HeLa cells, but virus preparations obtained after several undiluted passages through MK cells included plaque-formers in HeLa cells, suggesting that such plaque (HeLa)-forming viruses may have developed at a certain rate during multiplication of the original non-plaque (HeLa)-forming virus population in MK cells. Out of four lines of HeLa cells examined, two, including a clonal line S3, failed to support plaque formation by CA 9 virus.

Studies on the interaction between coxsackievirus A9 and HeLa cells. II. Mode of growth of coxsackievirus A9 in HeLa cell cultures and the effect of sulfated polysaccharide on plaque formation

For the purpose of clarifying the mechanism of plaque formation in HeLa cell cultures by coxsackievirus A9, which does not show definite CPE in fluid cultures, we investigated the growth pattern of the virus in HeLa cells, comparing plaque (HeLA)-forming and non-plaque (HeLa)-forming viruses. It was revealed that the yield of both viruses per cell was nearly the same, but non- plaque (HeLa)-forming virus was far less efficient in infecting HeLa cells. Dextran sulfate was effective in releasing more virus from cells, when HeLa cell cultures were infected with plaque (HeLa)-forming virus, but not in cultures infected with non-plaque (HeLa)-forming virus. From these experimental results, the mechanism by which plaques are formed in HeLa cell cultures by coxsackievirus A9 was discussed.

Localized submassive liver cell necrosis as a terminal event of liver carcinoma

Six cases of hepatocellular carcinoma (HCC) and one case of metastatic liver carcinoma in which SGOT, SGPT, and SLDH were suddenly and markedly elevated immediately before death are described. All had a large blood loss and systemic hypotension in the preterminal period; autopsy disclosed irregularly shaped, patchy necrotic areas or infarcts, often clearly demarcated by hemorrhagic rims, in the noncancerous liver parenchyma. Tumor growths in the intrahepatic portal branches were extensive in all six cases with HCC; in the metastatic case, invasion and narrowing of the portal branches were extensive. The incidence of this terminal catastrophe was 3.3% (6 of 184 cases) for HCC and 1.15% (1 of 87) for metastatic carcinoma. The terminal liver necrosis was probably a result of sudden reduction in portal perfusion which had been inadequate because of tumor thrombosis, combined with hypotension of hepatic arteries.

A possible mechanism of the generation of singlet molecular oxygen in nadph-dependent microsomal lipid peroxidation

A simplified system, consisting of NADPH, Fe3+-ADP, EDTA, liposomes, NADPH-cytochrome c reductase and Tris - HCl buffer (pH 6.8), has been employed in studies of the generation of singlet oxygen in NADPH-dependent microsomal lipid peroxidation. The light emitted by the system involves 1deltag type molecular oxygen identifiable by its characteristic emission spectrum and its behavior with beta-carotene. The generation of another excited species (a compound in the triplet state) could be demonstrated in this system by changes of light intensity and emission spectra which arise from photosensitizer (9,10-dibromoanthracene sulfonate, eosin, Rose-Bengal)-mediated energy transfers. Chemiluminescence in the visible region was markedly quenched by various radical trappers and by an inhibitor of NADPH-cytochrome c reductase, but not by superoxide dismutase. During the early stage of lipid peroxidation, the intensity of chemiluminescence was proportional to the square of the concentration of lipid peroxide. These characteristics suggest that singlet oxygen and a compound in the triplet state (probably a carbonyl compound) are generated by a self-reaction of lipid peroxy radicals.

Immunosuppressive effect of bacterial lipopolysaccharide on antibody response

Injection of endotoxins (bacterial lipopolysaccharide: LPS) several days prior to immunization causes the suppression of antibody response. The supressive effects of several kinds of LPS preparations on the plaque-forming cell (PFC) antibody response in the spleen of mice were examined after immunization with sheep red blood cells (SRBC). Glycolipids obtained from heptoseless mutants(Reform) of salmonella or its lipid A preparation coupled artificially with bovine serum albumin (BSA) are capable, like LPSobtained from a wild type (S form) strain, of inducing suppressionson of the PFC response, while alkaline-detoxified LPS can not. The refractory periods of the PFC response induced by LPS injection last only a few days. However, the use of cyclophosphamide (CY) together with LPS can extend the refractory periods of antigenic stimulation for several weeks. Injections of LPS andCY can also induce unresponsive states of OH agglutinin antibody response to antigenic stimulation with formalin-killed organisms of Escherichia coli or Salmonella enteritidis (presumably both thymus-independent antigens). These unresponsive states induced by LPS and CY are easily terminated by a transfer of syngeneic bone marrow cells but not by thymocyte transfer.