Biomedical subjects
Publications and source records attributed to Y Yasuda.
A patient with active systemic lupus erythematosus presented with generalized convulsions and acute myocardial infarction during the first trimester. Serial determinations of biochemical variables and liver histology indicated that preeclampsia might be responsible for the life threatening episodes.
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Poly-N-para-vinylbenzyl-lactonamide (PVLA)-coated reticulated polyurethane (PVLA-RPU) has been employed for the long-term maintenance of primary rat hepatocyte cultures. After 3 days of incubation of 2 x 10(7) hepatocytes/cm3 embedded in PVLA-RPU discs and kept in culture medium, most cells showed typical hepatocyte morphology, with some bile canaliculus-like intercellular spaces among the hepatocytes on examination with scanning and transmission electron microscopy. The cells were attached to the surface of the PVLA-RPU and formed multicellular spheroids in the reticulated pores. The hepatocytes maintained various liver-specific functions such as albumin secretion, ammonium metabolism, urea synthesis and gluconeogenesis, and they were viable. The liver-specific functions could be maintained for more than 1 month when the cells were kept in the rats' peritoneal cavities. This new system may be useful as a bioreactor for an artificial liver.
Chondroitin 6-sulfotransferase, which transfers sulfate from 3'-phosphoadenylyl sulfate to position 6 of N-acetylgalactosamine in chondroitin, was purified 1,430-fold to apparent homogeneity with a 22% yield from the serum-free culture medium of chick embryo chondrocytes by affinity chromatography on heparin-Sepharose CL-6B, wheat germ agglutinin-agarose, and 3',5'-ADP-agarose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme showed a single broad protein band with an apparent molecular weight of 75,000. Since the purified enzyme has an apparent molecular weight of 160,000 as judged by gel chromatography on Superose 12, the active form of chondroitin 6-sulfotransferase may be a dimer. The purified enzyme transferred sulfate to chondroitin, chondroitin sulfate, and corneal keratan sulfate. Chondroitin sulfate E from squid cartilage, dermatan, sulfate, and heparan sulfate hardly served as acceptors of the sulfotransferase. The sulfated product derived from keratan sulfate was degraded by keratanase but not by chondroitinase ABC.
Two dipicolinic acid (DPA)-binding macromolecules with molecular masses of about 440 kDa and 230 kDa were detected in the soluble fractions of dormant and germinated spores of Bacillus subtilis using native PAGE and an immunological technique. In SDS-PAGE, only one band with the molecular mass of about 50 kDa was found. Proteinase K partially digested the 440-kDa macromolecule of dormant spores to convert it into a 230-kDa one, and completely digested both the 440-kDa and 230-kDa bands of germinated spores. DNase I did not affect either DPA-binding macromolecules. This suggests that the two DPA-binding macromolecules are of similar origin, their main component is protein and a conformational change may occur during germination. DPA was not dissociated from the DPA-binding macromolecules by extensive dialysis and SDS treatment, suggesting the presence of a covalent bonding.
To examine the developmental toxicity of caffeine, Xenopus larvae just after hatching, were continuously exposed to 100-2,000 mg/L caffeine for 48 hours. Caffeine interfered with development of Xenopus larvae at a concentration of 100 mg/L and above in a concentration-dependent manner. Characteristic external abnormalities, such as shortened body with wavy fins, were observed, the severity of which was clearly concentration dependent. These larvae were frequently accompanied by abnormal body flexure and edema in the fin. Light microscopy revealed that exposure to caffeine induced severe damage in the myotome and neural tube, and at higher concentrations, the epidermal tissue was also affected. Myoblasts showed wide intercellular spaces, and their cytoplasm lost uniform staining. Ultrastructural studies of myoblasts revealed distinct myofibril disorganization and degeneration, and mitochondrial alterations. In the neural tube, cells at the dorsal part of tube showed wide intercellular spaces and some of them were segregated to the peripheral region. Furthermore, vacuole-like structures of various sizes appeared in the white matter. The outer layer of epithelial cells in the epidermis were vacuolated and swollen. With regard to the pathogenesis of myofibril damage, caffeine appeared to cause a disturbance of intracellular calcium regulation, by releasing calcium ions from the sarcoplasmic reticulum, and the mitochondrial changes observed in myotomal cells were considered to be reflective of this increased intracellular calcium ion levels. It is speculated that caffeine interferes with cell adhesion in the myotome and neural tube by affecting calcium ion regulation.
To examine the ventilatory response at the onset of passive leg movements during sleep in man and the concomitant changes in cardiac output (Qc), five healthy male subjects had their knee joints extended and flexed alternately at a frequency of about 60.min-1 for about 8 s. Minute ventilation (VI), respiratory frequency, tidal volume, end-tidal partial pressure of carbon dioxide and of oxygen, stroke volume (SV), heart rate (fc) and Qc were measured before, during and after passive leg movement during sleep stage III or IV (SLEEP). These values were compared with those of the awake condition (AWAKE). The VI increased significantly (P < 0.05) compared with the mean of five breaths preceding the movement (pre-movement) within one or two breaths at the onset of passive leg movements in both conditions. The difference between the mean of the first and second breaths after the onset of leg movement and pre-movement was 5.2 (SEM 1.9) l.min-1 for SLEEP and 2.7 (SEM 1.1) l.min-1 for AWAKE, respectively. Four of the five subjects showed a larger increase in ventilation during SLEEP compared with AWAKE. The fc increased significantly (P < 0.05) at the beginning of the passive movement in all cases, while SV showed an increase or decrease so that Qc showed no significant change in either condition. These results would suggest that afferent drive from moving limbs could produce an increase in ventilation without any change in Qc.
Blood was collected from Stage 13 to 14 (1) chick embryos. Primordial germ cells (PGCs) were separated from blood cells by Ficoll density gradient centrifugation. One hundred Rhode Island Red PGCs per embryo were transferred to the blood stream of Stage 14 to 15 White Leghorn embryos. Also, one hundred White Leghorn PGCs per embryo were transferred to the blood stream of Stage 14 to 15 Rhode Island Red embryos. Hatched male and female chicks were raised until sexual maturity, and progeny tests were performed by mating these PGC recipients with Rhode Island Red chickens of the opposite sex. Chicks apparently derived from the transferred PGCs, based on the feather color of the chicks, were produced from all 4 possible mating combinations. The present results indicate that the germ line of PGC recipient chickens consists of 2 distinct populations of germ cells.
Sensory disturbance around the corner of the mouth, in the palm of the hand and in the foot on the same side (cheiro-oral-pedal syndrome) has been reported only in 2 patients with brainstem lesion. We report 2 cases of cheiro-oral-pedal syndrome; the causative lesion was revealed by magnetic resonance imaging to be in the ventral postero-lateral and ventral posteromedial nuclei of the thalamus.
Two patients with mucosal cancer of the periampullary region were treated with papillo-choledochectomy, which entails removal of the papilla of Vater and the whole length of the common bile duct. The neoplasm is dissected out through the plane between the duodenal circular and longitudinal muscles, deep to the sphincter of Oddi and the fibromuscular layer of the bile duct. Pathological examination showed that cancer was confined to the mucosal layer without stromal invasion, and that the operation achieved radical cure. For mucosal cancer, papillo-choledochectomy is an alternative to pancreatoduodenectomy, provided that repeated frozen-section studies confirm the completeness of excision.
We studied a 67-year-old female who suffered from polymyositis associated with primary biliary cirrhosis (PBC). Liver dysfunction was revealed by a screening test. Antimitochondrial antibodies (AMA) and antinuclear antibodies were positive. Liver biopsy was compatible with PBC (Scheuer stage I). Four years later she showed severe weakness and atrophy on her four extremities. Laboratory examination showed a creatinine kinase level of 312 IU/l, IgM 416 mg/dl, and AMA titer 1:320. Muscle biopsy findings were compatible with polymyositis. Electron microscopic examination disclosed diffuse increase of mitochondria in subsarcolemma and intermyofibrils, which has not been reported until now in polymyositis associated with PBC.
A patient with migraine developed ophthalmoplegia, hemiparesis and cheiro-oral syndrome on the left side. T2-weighted MRI showed infarcts in the tegmentum of bilateral midbrains and right pons but no lesion in the cerebral or cerebellar hemisphere. Infarction in the tegmentum of brainstem secondary to the involvement of perforating arteries has not been reported in basilar artery migraine until now.
A case of isolated angiitis of the central nervous system (CNS) which first presented as intracranial hemorrhage during cesarean section is reported. Only one case of isolated angiitis of the CNS in post partum has been reported to date. Although a headache in labor and puerperium usually suggests subarachnoid hemorrhage, isolated angiitis of the CNS should be considered in the differential diagnosis.
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We investigated the effect of cimetidine and histamine on splanchnic circulation in the dogs. Hepatic artery, superior mesenteric artery and portal vein were cannulated to measure each blood pressure. Each blood flow was evaluated utilizing electromagnetic blood flowmetry. And vascular resistances were calculated by measured blood pressure and blood flow. Cimetidine, histamine, 2-PEA (H1-agonist), dimaprit (H2-agonist) and mepyramine maleate (H1-antagonist) were given by intravenous bolus to the dogs. Histamine caused vasodilation of hepatic artery but vasoconstriction of superior mesenteric artery and these effects were similar to the effect of 2-PEA. These hemodynamic responses to histamine were inhibited by H1-antagonist but not inhibited by H2-antagonist. Cimetidine produced dilatation of hepatic artery but constriction of portal vein, superior mesenteric artery and reduced total hepatic blood flow. These effects were not inhibited by H1-antagonist. We concluded that cimetidine did not stimulated H1, H2-receptors rather than had the own effects and that H1-receptor was superior to H2-receptor on splanchnic circulation in the dogs.
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We studied the interaction of influenza virus and a human lymphoblastic line, MOLT4 cells, as a model for that of influenza virus and human T lymphocytes. Influenza virus was found to grow relatively poorly in MOLT4 cells in terms of yield of plaque forming units (PFU) in the presence of trypsin. However, electron microscopy of infected cells revealed that a lot of viral antigens were accumulated in the cytoplasm as well as in the nucleus, and a number of budding virions were on the cell surfaces. Consistently, gel electrophoresis of infected cells demonstrated that the synthesis of virus proteins was abundant. These findings indicated that MOLT4 cells were permissive to influenza virus growth, with production of a relatively smaller number of infectious particles in terms of PFU. Production of interferon (IFN)-alpha and -gamma were not detected in this system by ELISA.