Purification and some properties of two NADP+-specific isocitrate dehydrogenases from an obligately psychrophilic marine bacterium, Vibrio sp., strain ABE-1

Two isozymes of NADP+-specific isocitrate dehydrogenase [ICDH; EC 1.1.1.42] were confirmed to be present in an obligately psychrophilic marine bacterium, Vibrio sp., strain ABE-1, on the basis of the temperature-activity curve and electrophoretic mobilities. These isozymes were separated and purified about 170-fold for isozyme I (specific activity at 40 degrees C, 24.3 units/mg protein) and about 180-fold for isozyme II (specific activity at 20 degrees C, 59.2 units/mg protein), though the isozymes were still not homogeneous. The molecular weights of these isozymes determined by gel filtration were both about 85,000, but the properties of the isozymes were considerably different from each other. The thermostability of isozyme I resembled those of mesophiles, but isozyme II was extremely labile above 20 degrees C. NaCl affected the ICDH isozymes in different ways; the salt protected isozyme I from heat inactivation, but not isozyme II. Nevertheless it enormously enhanced the activity of isozyme II at low concentrations. Moreover, these ICDH isozymes showed different pH optima, Km values for isocitrate, susceptibilities to concerted inhibition by glyoxylate plus oxalacetate, and effects of 2-mercaptoethanol on their stabilities.

Studies on biologically active halogenated compounds. 1. Synthesis and central nervous system depressant activity of 2-(fluoromethyl)-3-aryl-4(3H)-quinazolinone derivatives

Some 2-(fluoromethyl) analogues of 2-methyl-3-aryl-4-(3H)-quinazolinones have been synthesized and screened for CNS activities. It was shown that the 2-(fluoromethyl) analogues possess in general more potent CNS depressant activities and less toxicities than their parent compounds. Of particular interest were the 2-(fluoromethyl) analogues (22, 24, and 31) of methaqualone and 6-aminomethaqualone. Compound 24 was more potent in CNS depressant activity and less toxic than methaqualone. Compound 31 exhbited potent central muscle relaxing activity and markedly reduced toxicity as compared with 6-aminomethaqualone.

Successful treatment of Nocardia asteroides infection with minocycline in kidney transplant patients

Two cases of Noca dia asteroides infection were encountered out of 55 kidney transplant patients at Chiba University Hospital. One patient developed an extrapleural abscess and the other had a pulmonary infiltration with chest wall abscess. The patients were successfully treated by surgical drainage of the chest wall abscesses and by oral administration of minocycline. No adverse effects caused by minocycline were observed during the therapy. From 1900, when the first case of Nocardia infection was reported in Japan, there have been 60 cases reported in Japanese literature through 1973, including those we observed. This is the first report on nocardiosis in kidney transplant patients and on successful treatment of nocardiosis with minocycline in Japan.

Improved preparation and cooperative calcium contraction of glycerinated Vorticella

An improved method for the preparation of glycerinated Vorticella convallaria was investigated. The pretreatment of living vorticellas with a medium containing 0.1% saponins and subsequent treatment with an extraction medium containing 35% glycerol at about 0 degrees C was satisfactory. The equilibrium average length of contractile stalks of glycerinated vorticellas was measured at various free calcium concentrations in the reaction medium. It was found that the contractile element in the spasmoneme of the stalk is contracted by a cooperative interaction involving at least two calcium ions.

[Pharmacological studies of antipsychotic drug, penfluridol. 2. General pharmacological properties]

General pharmacological properties of penfluridol (TLP-607) a long-acting antipsychotic drug, were examined in experimental animals and the following results were obtained. 1) TLP-607 produced a lowering of arterial blood pressure and bradycardia but had almost no effect on respiration and peripheral blood flow. 2) TLP-607 slightly hypertension induced by dopamine, adrenaline and noradrenaline, but had no effect on hypotension induced by acetylcholine and histamine. 3) Antagonistic actions of TLP-607 on such spasmogens as acetylcholine, histamine and barium chloride were slightly stronger than those of haloperidol and chlorpromazine. 4) TLP-607 had neither ganglionic nor neuromuscular blocking action. 5) TLP-607 had a slight or no effect in the following experiments; protection against stomach ulcer, activity of ileum and uterus in vivo and in vitro, urinary volume and electrolytes excretion, and gastro-intestinal propulsion. These results suggest that TLP-607 has no striking peripheral actions in experimental animals.

Functional characterization of a naturally occurring antibody cytotoxic for a subpopulation of splenic T cells

Sera from old (greater than 6 months) New Zealand Black (NZB) mice were shown to contain an IgM antibody which was cytotoxic for thymus-derived (T) lymphocytes in the presence of rabbit complement. This antibody in the presence of complement markedly decreased the response of normal spleen cells to the T cell mitogen concanvalin A (Con A) but not to another T cell mitogen phytohemagglutinin-P (PHA-P). Responses of these treated cells to the polyclonal B cell mitogens, bacterial lipopolysaccharide (LPS), and polyriboinosinic-polyribocytidylic acid (poly[I]-poly[C]) were unimpaired. This naturally occurring NZB antibody was different from conventional anti-theta serum which abolished the response to both PHA-P and Con A. Moreover, the NZB serum affected spleen cells from both theta-C3H and theta-AKR mice. The ability of such serum to influence, differentially, Con A reactive cells as opposed to PHA-P-reactive cells, suggest that the NZB antiserum recognizes a subpopulation of T lymphocytes.

The mixed kidney cell-lymphocyte reaction in rats

Optimal conditions for obtaining the proliverative response in mixed kidney cell-lymphocyte culture (MKLC) have been determined in rats. The addition of 2-mercaptoethanol to the culture medium was essential for successful stimulation of lymphocytes by allogeneic kidney cells. Proliferative responses by standard MLC and MKLC were compared in rats with the same or a different Ag-B locus. In most strain combinations, there was a significant correlation between MLC and MKLC reactions, However, the DA-ACI combination, compatible at the Ag-B locus, consistently showed negative MLC and positive MKLC reactions. This suggested the possibility that this technique allowed the expression of kidney specific antigens.

Oxygenation properties and intraerythrocytic constituents of human blood when stored in different media of ACD and CPD

In the blood stored in acid-citrate-dextrose solution (ACD blood), the oxygen affinity and red cell 2, 3-diphosphoglycerate (2, 3-DPG) content showed parallel exponential decays with half-lives of 3 to 4 days. In the blood stored in citrate-phosphate-dextrose solution (CPD blood), the two parameters increased during the first 4 days before showing the same decay as that seen in the ACD blood. There was no significant change in the transmembrane pH gradient of the red cells, and thus the intracellular pH at the plasma pH of 7.40 was always in the range of 7.17 +/- 0.02 throughout the period of storage in ACD medium. In both ACD and CPD blood, the Hill exponent n was always normal (approximately 2.8) while the Bohr coefficient (delta log P50/delta pH) rose along with the lapse of time for preservation. The oxygen affinity of the CPD blood was less influenced by the red cell 2, 3-DPG than was that of the ACD blood. This phenomenon was thought to derive from higher concentration of salts within the CPD-stored red cells. The efficiency of blood oxygen transport in ACD and CPD blood was compared.

Specificity and immunosuppressive potency of a rabbit antimouse T cell-specific antiserum

An attempt was made to prepare a specific heterologous rabbit antimouse T cell antiserum (anti-MTLA) by absorbing rabbit antimouse thymocyte globulin (ATG) with spleen cells from BALB/c TXBM mice. Cytotoxicity data showed that whereas ATG was cytotoxic to both T and B cells, anti-MTLA was highly cytotoxic to only T cells. Whereas spleen cells treated with ATG and complement (C) failed to respond in all assays studied, spleen cells treated with anti-MTLA and C: (1) responded to the B cell mitogens but failed to respond to the T cell mitogens; (2) were able to stimulate allogeneic spleen cells but failed to respond to mixed lymphocyte culture (3) failed to act as T killer cells in the CML reaction but retained their ability to kill antibody-coated target cells; and (4) did not cause a graft-versus-host reaction when injected in allogeneic mice and increased their survival significantly. Furthermore, anti-MTLA was just as immunosuppressive in vivo as ATG in its ability to suppress the immune response to sheep red blood cells and prolong skin allograft survival. Anti-MTLA was found to be different in specificities from anti-theta serum by several points: (1) it was cytotoxic for T cells from both theta-C3H and theta-AKR mice; (2) it was highly immunosuppressive in vivo when compared to anti-theta serum; (3) absorption of anti-MTLA with mouse brain did not decrease the immunosuppressive activity; and (4) rabbit antimouse brain antiserum failed to show any immunosuppressive activity. These data indicate that anti-MTLA is a specific antiserum against a unique marker on T cells distinct from the theta marker.

Effect of antithymocyte serum on reaginic antibody formation in the rat

The effect of the time and dose of heterologous antithymocyte serum (ATS) on reaginic antibody formation was studied in the rat. Animals were treated with a single intravenous injection of ATS at various times before or after the primary immunization with dinitrophenylated Ascaris suum extract (DNP-As) and Bordetella pertussis vaccine. If animals were treated with a large lymphopenic dose of ATS shortly before or at the time of immunization, the production of reaginic as well as IgM and IgG antibodies was greatly suppressed, whereas the same treatment if given shortly after the immunization was started significantly enhanced and prolonged the reagin production. On the other hand, smaller doses of ATS even if given at the time of immunization only delayed the reaginic antibody response which also showed a marked prolongation. Furthermore, an unusual sequential production of IgM and IgG antibodies was observed in some of the ATS-treated animals. These results suggest that ATS can inhibit either inductive or regulatory function of the thymus-derived lymphocytes (T cells) depending on the time when it is administered and on the dose of ATS. Some other supporting data indicating that ATS inhibits the T cells specialized in the regulation of antibody formation are also presented.