IWAMA, K.Principal Component Analysis of Motokawa's Data on WavelengthDependence of Retinal Processes. Tohoku J. exp. Med., 1983, 141 (1), 1-8-Electric excitability of the human eye as determined by measuring the threshold for a sensation of phosphene in response to electric stimulation of the eye was found by Koiti Motokawa to increase temporarily after a brief illumination (J. Neurophysiol., 1949, 112, 475-488). While changing the wavelength of illuminating light widely, he found that the time course of the variation in the eye's electric excitability after illumination differed characteristically according to the wavelength. His data on this point (Tohoku J. exp. Med., 1949, 51, 197-205) were subjected to the principal component analysis. Three components were found necessary and sufficient for their linear combinations to reproduce time courses of the excitability enhancement after illumination with lights of varying wavelengths; one of the three components makes a great contribution to the excitability enhancement by green lights, the other to the one by red lights and the remainder to the one by blue lights. This is in support of Motokawa's view that his data are interpretable as summation effects of the three retinal processes which are excited preferentially by red, green and blue lights, respectively.
ASAKI, S., OTA, K., KANAZAWA, N., OHARA, S., ONODERA, H. and GOTO, Y. Ultrasonic Endoscopy. Tohoku J. exp. Med., 1983, 141 (1), 9-12 With the use of a linear scan type ultrasonic endoscope, the possibility of gastric fiberscopy with ultrasonic procedure in the estimation of the extent of deep infiltration of gastric cancer and in the transgastric diagnosis of pancreatic tumors was studied. Results revealed that the echogenicity of the tumor was more clearly recorded by ultrasonic endoscopy than routine ultrasonography taken via the abdominal wall. With improvements in both the probe and manipulation technique, the device is expected to achieve far-reaching contributions to the diagnosis of the deep invasion of gastric cancer and small-sized pancreatic tumors.
H. YAMANAGA Quantitative Analysis of Tremor in Minamata Disease. Tohoku J. exp. Med., 1983, 141 (1), 13-22 - Applying the techniques of power spectrum and pulse correlation, we carried out a quantitative analysis of tremor in normal subjects, patients with methyl mercury poisoning (Minamata disease) and patients with other diseases. We found that tremor of methyl mercury poisoning was different from physiological tremor and the other pathological tremors in frequency and amplitude.
MURAKAMI, M., MIURA, S., ITOH, I., GOTOH, N. and NAKAMICHI, H. Effects of Nucleotides and Nucleosides on the Activity of Cyclic AMP Phosphodiesterasefrom Rat Brain. Tohoku J. exp. Med., 1983, 141 (1), 23-31 -Cyclic nucleotides phosphodiesterase (PDE) was prepared from cerebrum of male rats and its kinetic properties were studied. The phosphodiesterase preparation exhibited two Michaelis constants, 8.7μM and 83.3μM. Adenine derivatives such as adenosine, 5'-AMP and 2'(3')-AMP inhibited the PDE activity at concentrations exceeding 7×10-3M, and 2'-deoxyadenosine inhibited the activity at lower concentrations (Ki=1.8×10-3M); its inhibiting efficacy was almost the same as that of theophylline (Ki=1.9×10-3M). Guanine derivatives, on the other hand, showed several different effects. Guanosine and 3', 5'-cyclic GMP activated the PDE at 10-5M and inhibited at concentrations higher than 10-4M. 2'(3')-GMP showed no effect, but 5'-GMP activated markedly at concentrations of 10-3 to 10-2M. Thymidine showed slight inhibitory effect, but cytidine or 2'-deoxycytidine had no effect. Uracil derivatives such as uridine, 5'-UMP, 3', 5'-cyclic UMP and 2'(3')-UMP activated the PDE at concentrations exceeding 3×10-3 M. These results indicate that individual nucleosides and nucleotides exhibit structure-activity relationship with PDE.
MORISAKI, N., MATSUOKA, N., SAITO, Y. and KUMAGAI, A. Effects ofPantethine and Its Metabolites on Fatty Acid Oxidation in Rat Liver Mitochondria. Tohoku J. exp. Med., 1983, 141 (1), 33-39 - The mechanism of the activating effect of pantethine [D-bis-(N-pantothenyl-β-aminoethyl) disulfide] on fatty acid oxidation was investigated in rat liver mitochondria. Pantethine, pantetheine and 4'-phosphopantetheine activated three steps of fatty acid oxidation, i.e., acyl-CoA synthetase, carnitine acyltransferase and intramitochondrial oxidation, to various extents. Although their effects may have been partly due to CoASH derived from them, they also had specific effects.
MORISAKI, N., MATSUOKA, N., SHIRAI, K., SASAKI, N., SAITO, Y. and KUMAGAI, A. Effect of Pantethine on Fatty Acid Oxidation in Microvessels ofRat Brain. Tohoku J. exp. Med., 1983, 141 (1), 41-45 - Fatty acid oxidation in brain microvessels decreased greatly when persistent hypertension developed in spontaneously hypertensive rats (SHR). Treatment of SHR with pantethine [D-bis-(N-pantothenyl-β-aminoethyl) disulfide] in vivo for 4 weeks restored their fatty acid oxidation activity to the control level. The mechanism of the activating effect of pantethine on fatty acid oxidation was investigated in brain microvessels. Pantethine and its metabolites (pantetheine and 4'-phosphopantetheine) activated three steps of fatty acid oxidation, i.e., acyl-CoA synthetase, carnitine acyltransferase and intramitochondrial oxidation. The relation between changes in fatty acid oxidation activities and injuries of brain microvessels and the protective effect of pantethine against such injuries is discussed.
KUGIMIYA, T., GUNST, M.A., LAVER, M.B. and DUVELLEROY, M.A. Dependencyof O2-Affinity Effects on O2 Consumption in the Isolated Rat Heart. Tohoku J. exp. Med., 1983, 141 (l), 47-59-We have studied the effect of a decrease in hemoglobin-O2 affinity (increased P50) on O2 delivery in the non-paced, isolated, blood-perfused rat heart before and after coronary vasodilatation with and without an increase in myocardial O2 consumption (MVO2) produced with isoproterenol. Changes in perfusate P50 were produced with orthoiodosodium benzoate (OISB). Low concentrations of isoproterenol (0.74μg/liter) caused no significant changes in coronary blood flow (QCOR) or MVO2 per beat. Perfusion with OISB-treated (8mM) blood increased P50 from 29 to 33 mmHg at constant pH. MVO2 per beat increased significantly, QCOR did not change, and the ratio QCOR/MVO2, a reflection of the flow/metabolism distribution, decreased to values obtained in the absence of isoproterenol. With high doses of isoproterenol (5.0μg/liter), MVO2 per beat and QCOR/MVO2 increased. Addition of OISB (13mM) increased P50 from 29 to 39 mmHg, with no significant reduction in either QCOR or the QCOR/MVO2 ratio. Our data suggest that a decrease in blood-O2 affinity affects myocardial O2 delivery depending on the initial metabolic requirement: at basal MVO2 changes in the distribution of myocardial blood flow are probably secondary to the effects of PO2 on vessels that supply metabolically less active regions; at high MVO2 and following a maximum increase in capillary density, changes in vascular PO2 appear less effective than locally generated metabolic vasodilators, and distribution of blood flow is unaffected.
OGAWA, S., KUROKAWA, I. and AKINO, T. Characteristics of PhospholipidsAssociated with Fibrins in Partial Thromboplastin Test. Tohoku J. exp. Med., 1983, 141 (1), 61-69 - With the aim to obtain information on the role of individual phospholipids in the coagulation process, lipids associated with fibrins formed with partial thromboplastin reagents were examined. In the absence of the partial thromboplastin reagents, phosphatidylethanolamine and phosphatidylserine plus phosphatidylinositol in citrated plasma were incorporated preferentially into fibrin, although the main phospholipid associated with the fibrin was phosphatidylcholine. In the presence of the partial thromboplastin reagents, most phospholipids unseparable from the corresponding fibrins appeared to be derived from the reagents with little selectivity for individual phospholipids, except for lysophosphatidylcholine. These results suggest that phospholipids other than thromboplastic phospholipids may play some role in the coagulation process. The incorporation of lysophosphatidylcholine in the reagent into fibrins was significantly enhanced by the addition of activating agents (celite and ellagic acid), suggesting one role of the activating agents in fibrin formation.
FURUHASHI, N., TAKAHASHI, T., FUKAYA, T., KONO, H., SHINKAWA, O. and SUZUKI, M. Human Plasma ACTH, β-Lipotropin and β-Endorphin during Delivery. Tohoku J. exp. Med., 1983, 141 (1), 71-76 Adrenocorticotropic hormone (ACTH), β-lipotropin (β-LPH) and β-endorphin (β-EP) immunoreactivities were measured by high sensitive radioimmunoassay in maternal and umbilical cord plasma samples which were obtained simultaneously in 12 cases. Mean ACTH levels in cord and maternal plasma were significantly higher than those of 8 normal adults. Mean β-EP to β-LPH molar ratio of 0.19 in maternal plasma was different from that of cord plasma (0.13). There was no significant correlation between β-EP levels, or between β-LPH levels, in the paired fetal and maternal samples. These data suggest that β-LPH and β-EP elevate during labor and delivery in response to the stress. Beta-LPH and β-EP in cord plasma are of fetal and/or placental origin.
MATSUNO, S., KANO, K., MIYAGAWA, K., YAMAUCHI, H. and SATO, T. Effectsof Long Term Intravenous Administration of Ethanol on Rat Pancreas. Tohoku J. exp. Med., 1983, 141 (1), 77-89 - Pancreatic exocrine function and morphologic changes were investigated in groups of rats receiving solutions of ethanol by oral or intravenous route, or equicaloric doses of glucose solution by intravenous route daily for a period of 4 weeks. Comparable degrees of exocrine dysfunction and morphologic changes in the pancreas at the ultrastructural level were observed in the groups given ethanol orally and in those receiving i.v. injections of ethanol, suggesting that neither intragastric ingestion nor high blood levels of alcohol is required for alcohol to exert its pancreatotoxic effects. All groups of rats receiving ethanol or glucose showed signs and pathologic findings of nutritional disorder, and at 4 weeks of treatment, electron microscopic abnormalities of the pancreas were more pronounced and higher in incidence in the groups given ethanol p.o. or i.v. than in the groups given i.v. doses of glucose. There was no microscopic evidence of protein plug or other changes in the region of origin of the pancreatic duct system in rats after 18 months of oral administration of ethanol. The present findings indicate that the cytotoxic effect of alcohol on acinar cells and nutritional disorder associated with alcohol ingestion constitute important factors in the pathogenesis of chronic alcoholic pancreatitis.
KAMEYAMA, J., MIYAKAWA, H., SASAKI, I. and SATO, T. Effect of Cimetidineon Gastric Mucosal Barrier in Dogs. Tohoku J. exp. Med., 1983, 141 (1), 91-98 -The effect of cimetidine on the gastric mucosal barrier (GMB) was investigated in adult mongrel dogs with a Heidenhain pouch. A linear correlation was found between the net flux of Na+ and H+, and transmucosal electrical potential difference (PD). The PD was thus considered to be a good indicator for the degree of impairment of the GMB which can be determined easily with high reproducibility. When irrigated with HCl alone, there was a slight, though not significant, upward tendency of the PD following intravenous cimetidine. The destruction of the GMB during perfusion with HCl plus sodium taurocholate resulted in a marked reduction of the PD. This response of the PD was significantly reduced by the injection of cimetidine. These results indicate that cimetidine protects the GMB from impairments by bile acid.
UMEDA, M., NODA, K., TANAKA, K., YAMANE, I. and MATSUYA, Y. Cultivationof V79 Cells in Serum-Free Medium Containing Bovine Serum Albumin and the Useof Gelatin as an Attachment Factor. Tohoku J. exp. Med., 1983, 141 (1) 99-106 -V79 cells were cultivated in a serum-free medium. When a serum-free, bovine serum albumin-containing medium was used, removal of trypsin after cell detachment during subcultivation was necessary for routine mass cultivation. For colony formation addition of an attachment factor to the medium was further necessary. Gelatin was proved to serve as a good attachment factor in the colony formation and it could be substituted for fibronectin as an attachment factor for serum-free cultivation of many types of cells.
MINATO, K., TAKAHASHI, K., IKENO, N., WATANABE, M., ENDO, H. and YAMAMOTO, H. Evidence for Prolactin-Releasing and Release-Inhibiting Effects of Melatonin, Serotonin and Arginine Vasotocin. Tohoku J. exp. Med., 1983, 141 (1), 107-116 - Adult female Wistar rats (in 12hr light/12hr dark) were pinealectomized (PX) or sham-operated (SO) either 21 days after ovariectomy or on the 15-17th day of pregnancy. Ovariectomized (OVX) rats were injected with estrogen and progesterone (EP) 48hr before decapitation. Melatonin, serotonin or arginine vasotocin (AVT; 50, 100 or 200μg) were administered intravenously into OVX-EP rats 9 days after pineal removal. In PX and SO groups, the same study was done 3 days after delivery. Sera and pituitaries were collected 30min after injection in order to determine prolactin (PRL) levels. Fifty μg melatonin significantly suppressed serum PRL levels in PX-OVX-EP rats and PX postpartum rats, but had not significant effect in SO-OVX-EP or PX postpartum rats. After administration of AVT, serum PRL levels markedly rose in PX and SO rats. These results suggest that melatonin may act not only to stimulate but also to inhibit rat PRL secretion and that the stimulatory function would be superior to its inhibitory function when the pineal gland is intact.
TSUCHIDA, S., NISHIZAWA, O., KOINUMA, N., HARADA, T., MORIYA, I., SATOH, S., EBINA, K. and NOTO, H. Paired Extraluminal Strain Gauge Force Transducersfor Measuring Urethral Movements. Tohoku J. exp. Med., 1983, 141 (1), 117-118 - Paired extraluminal strain gauge force transducers were implanted in the urethra to measure separately and simultaneously both longitudinal and transverse movements of the urethra. The advantage of our paired strain gauge force transducers is that both longitudinal and transverse changes of urethral movements can be detected.
YAMAGUCHI, O., IWATA, K., SUZUKI, M., ICHIKAWA, S., SATO, K. and TSUSHIDA, S. Animal Model of Megaureter. Tohoku J. exp. Med., 1983, 141 (1), 119-120 - A rabbit model with a megaureter was produced by the partial obstruction of the ureter. The resultant dilatation obtained after the chronic obstruction (more than 100 days) was approximately 4 times greater than the normal ureteral diameter.
YAMAGUCHI, O., IWATA, K., SUZUKI, M., ICHIKAWA, S. and KOBAYASHI, R. The Contents of Contractile Proteins in the Normal and Dilated Ureter. Tohoku J. exp. Med., 1983, 141 (1), 121-122 - Using an SDS-polyacrylamide gel electrophoresis, the contractile protein content of the normal rabbit Ureter was compared with that of the dilated ureter. The relative amounts of the actin and myosin were significantly decreased in the dilated ureter.
NAKAMURA, S. Decrease in Female University Students Positive for HepatitisB e Antigen. Tohoku J. exp. Med., 1983, 141 (1), 123-124 - Since 1976 university students were screened for hepatitis B surface antigen (HBsAg) every year, and sera positive for HBsAg were tested for hepatitis B e antigen (HBeAg) and antibody to HBeAg (anti-HBe). Yearly changes in the prevalences of HBeAg in the male HBsAg carrier students were relatively small and statistically not significant. In the female HBsAg carrier students, however, HBeAg which was positive by immunodiffusion in 47% of the students in 1976-79 was not detected by radioimmunoassay in 1981 and 1982. The difference of the prevalences of HBeAg between 1976-79 and 1981-82 was statistically highly significant (p<0.001). It is suggested that seroconversion from HBeAg to anti-HBe in female HBsAg carriers is recently accelerated.