Control of the rate of phosphocreatine resynthesis after exercise in trained and untrained human quadriceps muscles

We examined the effect of differences in exercise intensity on the time constant (t _c) of phosphocreatine (PCr) resynthesis after exercise and the relationships betweent _c and maximal oxygen uptake (VO_2max) in endurance-trained runners (n = 5) and untrained controls (n = 7) (average VO_2max = 66.2 and 52.0 ml · min^–1 · kg^–1, respectively). To measure the metabolism of the quadriceps muscle using phosphorus nuclear magnetic resonance spectroscopy, we developed a device which allowed knee extension exercise inside a magnet. All the subjects performed four types of exercise: light, moderate, severe and exhausting. The end-exercise PCr: [PCr + inorganic phosphate (P_i)] ratio decreased significantly with the increase in the exercise intensity (P < 0.01). Although there was little difference in the end-exercise pH, adenosine diphosphate concentration ([ADP]) and the lowest intracellular pH during recovery between light and moderate exercise, significant changes were found at the two higher intensities (P < 0.01). These changes for runners were smaller than those for the controls (P < 0.05). The _c remained constant after light and moderate exercise and then lengthened in proportion to the increase in intensity (P < 0.05). The runners had a lowert _c at the same PCr and pH than the controls, particularly at the higher intensity (P < 0.05). There was a significant correlation betweent _c and [ADP] in light exercise and betweent _c and both end-exercise PCr and pH in severe and exhausting exercise (P < 0.05). The threshold of changes in pH andt _c was a PCr: (PCr + P_i) ratio of 0.5. There was a significant negative correlation between the VO_2max andt _c after all levels of exercise (P<0.05).However, in the controls a significant correlation was found in only light and moderate exercise (P < 0.05). These findings suggest the validity of the use oft _c at an end-exercise PCr:(PCr + P_i) ratio of more than 0.5 as a stable index of muscle oxidative capacity and the correlation between local and general aerobic capacity. Moreover, endurance-trained runners are characterized by the faster PCr resynthesis at the same PCr and intracellular pH.     

Stimulation of prostaglandin E2 synthesis by exogenous phospholipase A2 and C in rabbit kidney medulla slices.

We have investigated the effects of phospholipase A2 and C on the synthesis of prostaglandin E2 in rabbit kidney medulla and the release of fatty acids from the medulla slices. Exogenous phospholipase A2 [from Naja naja (Indian cobra) venom] and phospholipase C (from Clostridium welchii) stimulated prostaglandin E2 production in a dose-dependent manner. At the maximal effective concentrations (0.5 unit of phospholipase A2/ml, 2 units of phospholipase C/ml), phospholipase C increased prostaglandin E2 formation to the level observed with phospholipase A2. Phospholipase A2 enhanced the release only of unsaturated fatty acids, whereas phospholipase C stimulated the release of individual free fatty acids (C 16:0, C 18:0, C 18:1, C 18:2 and C 20:4). Moreover, p-bromophenacyl bromide inhibited phospholipase A2-stimulated prostaglandin E2 production and the release of fatty acids, but it had no influence on prostaglandin E2 formation and the release of fatty acids increased by phospholipase C, indicating that the stimulatory effect of phospholipase C is not mediated through the activation of endogenous phospholipase A2. These results suggest the presence of diacylglycerol lipase and monoacylglycerol lipase in the kidney and the importance of this pathway in prostaglandin synthesis by the kidney.     

Levamisole in postoperative adjuvant immunochemotherapy for gastric cancer

Summary The usefulness of LMS in postoperative immunochemotherapy of gastric cancer was investigated. In compliance with the protocol, MMC was given at a dose of 20 mg on the day of gastrectomy, and an additional 10 mg on the next day IV. The patients receiving 600 mg Tegafur daily were then divided into two groups according to whether LMS was also given or not. LMS was administered for 3 days before the operation in a daily dose of 150 mg and for 1 year or more after operation according to a schedule of 3 days' administration followed by an 11-day interval. The 2-year follow-up demonstrated that in stage III patients, the LMS (+) regimen was superior to the LMS (–) regimen, since the former prolonged the relapse-free interval significantly. The survival rate for stage III disease was also significantly higher in the LMS (+) than in the LMS (–) group. There was no significant difference in the incidence of subjective or objective side-effects between two groups. The incidence of agranulocytosis was comparable in the two groups.Gastrointestinal Cancer Research Group, Japan Levamisole Research AssociationChairmen of the Gastrointestinal Cancer Research Group, Japan LMS Research AssociationController of the Gastrointestinal Cancer Research Group, Japan LMS Research AssociationMembers of the Data Collection and Analysis SubcommitteeThis study was carried out by the Gastrointestinal Cancer Research Group, Japan LMS Research Association (directed by Prof. Kiyoshi Inokuchi, Dept. of Surgery, Kyushu University and Prof. Eiro Tsubura, Dept. of Internal Medicine, Tokushima University). The results were presented in part at the 19th General Meeting of the Japanese Society for Gastroenterological Surgery in February, 1982     

Two cholesterol ester hydrolases. Distribution in rat tissues and in cultured human fibroblasts and monkey arterial smooth muscle cells.

Hydrolytic activity against acetone-dispersed [4-14C]cholesterol oleate has been assayed as a function of pH in seven parenchymal tissues, blood cells, and plasma of the rat, as well as in cultured human fibroblasts and monkey (Macaca nemestrina) arterial smooth muscle cells. Both acid and neutral hydrolytic activities were present in all of these except rat plasma. The pH optima were in all cases close to pH 4.5 and pH 6.8. Acid activity was quite constant from tissue to tissue, while neutral activity varied greatly, being greatest in adrenal, testis, and adipose tissue. Subcellular fractionation of human fibroblasts allowed demonstration that activities at pH 4.5 and pH 6.8 were concentrated in different fractions, apparently lysosomal and polysomal, respectively. It appears most cell types, including fibroblasts and smooth muscle cells, contain two separate enzymes capable of hydrolyzing cholesterol esters. The neutral pH polysomal enzyme, which is especially prominent in certain tissues, may have a function related to the specialized roles of these tissues.     

Detection and characterization of idiotype-specific enhancing cells generated in mice immunized with idiotype

Cellular interaction between MOPC-104E (M104E) cross-reactive idiotypic (CRI) antibody-producing B lymphocytes and lymphocytes generated by immunization with the relevant idiotype, M104E, was investigated. Adoptive transfer of M104E idiotype-primed and normal spleen cells into 600R x-irradiated syngeneic recipient mice resulted in striking enhancement of the M104E-CRI positive antibody response upon simultaneous immunization of recipients with dextran B1355S. The enhancement was not attributable to a simple additive effect but was due to synergistic cooperation between the two lymphocyte populations. This synergistic enhancement of the anti-idiotype immune cells producing CRI antibody was specific for MOPC-104E CRI, and was reproducible in an in vitro culture system. Because of the cellular characteristics of the enhancing cells, they were assumed to be B lymphocytes specific for the corresponding idiotype, since the activity was not abrogated by treatment with anti-Thy-1, anti-Lyt-1, anti-Lyt-2, or anti-brain-associated theta antisera plus complement, but was eliminated by means of a planning method using a rabbit-anti-mouse immunoglobulin-coated or idiotype-coated dish. The mechanisms of interaction between the CRI-positive B cells and anti-idiotypic B cells in response to the thymus-independent antigen dextran B1355S are discussed.     

Microinjection of macromolecules into normal murine lymphocytes by means of cell fusion. II. Enhancement and suppression of mitogenic responses by microinjection of monoclonal anti-cyclic AMP into B lymphocytes

Reproducible methods are now available for introducing protein molecules such as antibodies into normal murine lymphocytes by fusion with protein molecule-containing erythrocyte ghosts. Monoclonal antibodies against cyclic AMP were raised by hybridoma technique and packed into erythrocyte ghosts. Then, monoclonal anti-cyclic AMP containing ghosts were fused with splenic B lymphocytes by polyethylene glycol-mediated fusion at various intervals after LPS stimulation. This method made it possible for us to quantitatively microinject antibodies into B lymphocytes. Microinjection of anti-cyclic AMP antibody molecules into lymphocytes at a very early stage of LPS stimulation resulted in a marked enhancement of DNA synthetic responses as well as increased numbers of plaque-forming cells. Intracellular cyclic AMP levels were found to be markedly decreased after microinjection of monoclonal anti-cyclic AMP, suggesting that lowering the intracellular cyclic-AMP level in the B lymphocytes at an early stage of stimulation might have induced the enhanced proliferative as well as differentiative responses to LPS. Similar enhancing effects on cell proliferation were obtained when antibodies were injected 18 hr after stimulation. Microinjection of anti-cyclic AMP at 12 hr after culture, however, inhibited the DNA synthetic responses, and induction of plaque-forming cells was suppressed when anti-cyclic AMP was injected 6 hr after LPS stimulation. The present data suggest the biphasic regulatory roles of cyclic AMP at the early stage of B lymphocyte activation. This approach may be useful in identifying regulatory molecules in B lymphocyte induced by mitogenic or antigenic stimulation.     

Relation of the structure and function of ferricytochrome c bound to the phosphoprotein phosvitin

The relationship between the structure and function of ferricytochrome c bound to the phosphoprotein phosvitin was investigated. The rates of reduction of phosvitin-bound ferricytochrome c by cytochrome b2, ascorbate and the superoxide radical generated by xanthine oxidase wer repressed where the binding ratio was less than half the maximum, but at higher ratios they were restored gradually with increase in the ratio. The affinity of cytochrome b2 for cytochrome c was not affected by binding of cytochrome c to phosvitin. The redox potential of the bond form was lower than that of the free form and only decreased with decrease in the ratio. The conformatin around the heme moiety and the electronic structure of the heme group of bound ferricytochrome c were similar to those of free ferricytochrome c, but the conformational stability in the vicinity of the prosthetic group was related to the binding ratio as ratios above half the maximum and was well correlated with the reduction rate. Since the binding of cytochrome c to phosvitin is much stronger at binding ratios below half the maximum, these results suggest that this binding strength exclusively affects the conformational flexibility of the heme crevice in the cytochrome molecule, thus altering the reduction rate.     

Differences in growth response to hydrocortisone and ascorbic acid by human diploid fibroblasts

Summary The effects of hydrocortisone and ascorbic acid on growth parameters were measured in human diploid skin fibroblasts from fetal and adult donors. In the presence of culture medium containing 10% fetal bovine serum, 0.3 μM hydrocortisone produced a 20% increase in the population growth rate and a 50 to 70% increase in the confluent density of fibroblasts from adult donors. Daily addition of 28 μM ascorbic acid also stimulated the population growth rate and cell density at confluency. The effects of hydrocortisone and ascorbic acid on the final cell density were additive. The action of hydrocortisone was restricted to cells in log-phase growth, whereas ascorbic acid affected cells in both the log and the postconfluent phases of the growth cycle. In fibroblasts from fetal donors, ascorbic acid was stimulative but hydrocortisone was not. The data suggest that whereas both compounds stimulate cell growth in an additive manner, they do so by different cellular mechanisms. This investigation was supported in part by USPHS Grants AM 02456, AM 05020 and AM 15312, and by the Kroc Foundation, No. UW 63-2986. Dr. Rowe is a fellow of the Helen Hay Whitney Foundation. Dr. Fujimoto is a recipient of a Research Career Development Award, AM 47142, from NIAMDD.     

Duplication of the segment q12.2→qter of chromosome 22 due to paternal inversion 22(p13q12.2)

Summary A 1730-g male infant, born at 37 weeks gestation, had multiple congenital anomalies, consisting of microcephaly, hypertelorism, bilateral cleft lip and palate, micrognathia, lowset ears, and cryptorchidism. Chromosome analysis showed a recombinant 22 derived from the paternal inversion (22) (p13q12.2). The proband's karyotype is 46,XY,rec(22),dup q,inv(22)(p13q12.2)pat, which has a duplication of q12.2qter. An identical recombinant has been reported in a female infant in Mexico whose mother was a carrier of the inversion. Similar congenital anomalies present in these two patients demonstrate the phenotype of duplication of the distal long arm 22. This report also documents the occurrence of an identical inversion in two apparently unrelated Mexican families.