Biomedical subjects

K Kadota

Publications and source records attributed to K Kadota.

At least 109 records · Page 6Linked to original sources

PubMed1992

Localization of a 82 kDa protein in postsynaptic density and its association with cytoskeletons.

A fraction of synaptic junctional complex (SJC) was prepared from rat synaptosomes and served as antigen material to produce monoclonal antibodies (Mab) for examining the component proteins of the SJC. An antibody, Mab SJ-8, was obtained, which recognized a protein with a molecular weight of 82,000 Da in the SJC preparation by immunoblot analysis. The immunohistochemical localization of the 82 kDa protein was studied with the rat cerebellum. Mab SJ-8 labeled the peripheral areas of the Purkinje and granule cells. Small punctate areas were also stained in the molecular layer with SJ-8. Intracellular localization of the protein was examined with rat brain synaptosomes. Immunoelectron microscopy demonstrated that Mab SJ-8 strongly labeled the postsynaptic density (PSD) and also a fibrous network spreading out of it. However, the antibody did not label the pre- or post-synaptic membrane or the cleft material.

Animals↗

PubMed1992

A study of clinical response to different kinds of neuroleptics in first time medicated schizophrenics.

Clinical responses to different kinds of neuroleptics in fresh schizophrenics were prospectively investigated. The scales used were the Global Assessment Scale (GAS), Brief Psychiatric Rating Scale (BPRS) and Psychiatric Evaluation Scale (PES). The 48 subjects were classified into three groups, 16 in the phenothiazine response group, 19 in the butyrophenone response group and 13 in the nonresponse group. For the schizophrenics who displayed negative symptoms such as motor retardation and blunted affect, while displaying milder positive symptoms, phenothiazine drugs were effective. Contrarily, for the schizophrenics who displayed severe positive symptoms such as hallucination and delusion while displaying milder negative symptoms, butyrophenone drugs were effective. Large dosages of the drug did not enhance the curative effect in most cases.

Adult↗

PubMed1992

Aggressive fibromatosis in a cat.

A case of aggressive fibromatosis (extra-abdominal desmoid) found in a 9-month-old male mixed breed cat is described. The right forearm was almost completely effaced by fibrous tissue and there were some tumours in the area from the shoulders to the mandible. These tumour-like tissues were composed of abundant collagen fibres and sparse numbers of well-differentiated fibroblasts, whereas their growing pattern was aggressive and non-encapsulated. There was dense growth of immature fibroblasts and multinucleated giant cells in some areas. Vimentin immunohistochemistry and electron microscopy suggested that the giant cells had close relation to the fibroblasts, and such areas may be the sites of cell proliferation. This case is different from nodular fasciitis and may be a proliferative disorder induced by feline oncogenic retrovirus.

Animals↗

PubMed1992

Synaptic vesicle increase correlated to potentiation of transmission at the synapse of the cat superior cervical ganglion in vivo.

Changes in the pattern, number and size of synaptic vesicles during transmitter release were examined in the synapses of the cat superior cervical ganglion (SCG) in vivo in relation to alteration in the amplitude of postganglionic compound action potential (PGP). Stimulation of the preganglionic nerve fibers at 10 Hz caused an increase in the mean amplitude of PGP. It became augmented by approximately 30% compared to control 10-30 sec after starting the stimulation, and then gradually declined to reach a plateau after 4-6 min. This level, about 20% higher in value than control, was sustained until the end of 30 min of stimulation. The nerve terminal was divided into two areas to examine topographically the numerical changes in synaptic vesicles (SVs): zone I on the presynaptic membrane encircled with a diameter equivalent to the active zone length, and zone II occupying the remaining area outside zone I. The synaptic vesicle density in zone I (vesicle number/microns 2) was 96.9 +/- 4.8 (mean +/- S.E.M.) in the unstimulated control ganglia and 128.8 +/- 9.4 (mean +/- S.E.M.) in the ganglia stimulated for 10-30 sec, which was 30% higher in value than control. Then, it decreased slightly reaching a plateau, 20% higher in value than control. The diameter distribution of the SVs showed that their diameters in zone I (56.6 nm mean) were larger than those (51.6 nm mean) in zone II, and that prolonged stimulation induced smaller vesicles in both areas. The results showed that the increase in SV number in zone I correlated well with the elevation of PGP.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

PubMed1992

[Transcranial magnetic stimulation of the facial nerve].

It was the object of the present study to determine whether transcranial facial nerve stimulation using a magnetic coil can be clinically applicable, and to find the site where the facial nerve is best stimulated. A magnetic coil was placed over the parieto-occipital skull of the subjects for stimulation, and the facial nerve was electrically stimulated in its intracranial and peripheral courses. Then an electromyogram was recorded from the nasalis muscle of the face on the stimulated side. In 9 healthy volunteers, 18 facial nerves received magnetic and electric stimuli in the peripheral region, and the actual site of stimulation was estimated from the conduction velocity of the nerve. The conduction velocity was 56.6 +/- 4.8 m/s, and the latency between CMAPs for electric at the magnetic stimuli to the posterior tragus was 1.23 +/- 0.21 ms. Therefore, the position stimulated by magnetic coil was estimated to be 70.0 +/- 11.4 mm central to the posterior tragus, i.e., near the root exit zone. In two patients undergoing surgery in the cerebellopontine angle, transcranial magnetic stimulation and electrical stimulation of the intracranial facial nerve were compared intraoperatively. The CMAP produced by transcranial magnetic stimulation coincided closely with that produced by direct electrical stimulation of the root exit zone. Thus, the facial nerve was stimulated at the root exit zone, and this method could be expected to be useful for evaluation of disorders of the intracranial facial nerve.

Adult↗

PubMed1992

[Transorbital penetrating brain injury].

Transorbital penetrating brain injury is rare during this time of peace. In our paper, we reported seven cases of these injuries and discussed the mechanism and treatment of intracranial complications. Transorbital penetrating brain injuries were caused by thin, long and relative hard objects such as chop-stick (case 3), pencil (case 6), bamboo stick (case 1, 2, 7) and a piece of metal (case 4, 5). CT scan, MRI and angiography demonstrated a large variety of intracranial complications. For instance, intracerebral hematoma, cerebral contusion, intraventricular hemorrhage, pneumocephalus, brain stem injury and carotid cavernous sinus fistula. We had no case of infectious complications such as meningitis and brain abscess. If the direction of the injuring object runs parallel to the orbital roof, it penetrates the cranial cavity commonly via the superior orbital fissure or the optic canal, which routes provide direct access without bone fracture. This direction will cause critical intracranial complications such as CCF or brain stem injury. If the injuring object runs upward and across the orbital roof which has thin bone and therefore offers little resistance, the frontal lobe will be easily damaged, and it will cause intracerebral hematoma. But the prognosis for this type of injury is not so poor because we can easily remove the hematoma and the foreign body. With our treatment policy of "pull and see", all our cases but one recovered well. The one exception was a case in which a large intracerebral hematoma was over-looked in an ophthalmological clinic. This patient died. Nowadays, CT scan and MRI give clear information about the anatomical location of injuring objects and intracranial complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Purification and characterization of three forms of differently glycosylated recombinant human granulocyte-macrophage colony-stimulating factor.

We have purified recombinant human granulocyte-macrophage colony-stimulating factor (hGM-CSF) produced in human lymphoblastoid Namalwa cells. From the results of tunicamycin treatment and N-glycosidase F digestion, it was demonstrated that Namalwa-derived hGM-CSF was highly glycosylated at two potential N-glycosylation sites and several O-glycosylation sites as previously shown for naturally occurring hGM-CSF. We classified the hGM-CSF molecules into three groups according to the molecular weight corresponding to the degree of N-glycosylation: the molecules with two N-glycosylation sites occupied (designated 2N), the molecules with either site glycosylated (1N), and the molecules lacking N-glycosylation (0N). Despite such varied degrees of N-glycosylation, almost all molecules were O-glycosylated. To investigate the role of carbohydrate moieties of hGM-CSF, we isolated each form of hGM-CSF and examined its biological properties. The 2N-type showed 200-fold less in vitro specific activity compared with unglycosylated Escherichia coli-derived hGM-CSF, although the activity of the 0N-type was equivalent to that of the E. coli-derived material. The 1N-type showed an intermediate level of activity. However, in terms of clearance from blood circulation in the rat, the 2N-type showed a half-life five times longer than that of the 0N-type and E. coli-derived hGM-CSF. From these findings, we concluded that N-linked carbohydrate moieties of hGM-CSF play conflicting physiological roles in the efficacy of the protein in vivo but that O-linked carbohydrate moieties do not have such effects.

Animals↗

PubMed1991

An ultrastructural study of vulval myofibroblastoma in a cow.

A case of myofibroblastoma in a 3-year-old Japanese Black cow is described. Raised tumours which formed in the anus and in the labium and vestibulum of the vulva during pregnancy were excised surgically. The latter two tumours had dense growth of slender spindle cells beneath the epithelium, and fibrous connective tissue at the periphery. The anal tumour consisted of abundant collagen and sparse numbers of spindle cells. Proliferating cells contained moderate amounts of thin filaments with focal densities as well as well-developed rough endoplasmic reticulum and Golgi apparatus, and desmosome-like structures were found between the cells. These cells were distinguishable from leiomyoma cells containing abundant thin filaments and poorly-developed organelles. In the neoplastic lesions, there was an infiltration of many lymphocytes, plasma cells and macrophages.

Animals↗

PubMed1991

A new relaxing factor in supernatant of incubated rat peritoneal neutrophils.

It was found that when rat peritoneal neutrophils were added to an organ bath, they released an unstable vasoactive substance designated as neutrophil-derived relaxing factor (NDRF), which is similar to endothelium-derived relaxing factor. Besides NDRF, a more stable (activity maintained for at least 7 days at -80 degrees C) relaxing factor was found to be generated in the supernatant after the incubation of rat peritoneal neutrophils in buffer. This supernatant relaxing factor (SRF) induced an increase in the guanosine 3',5'-cyclic monophosphate content of aortic strips. Its relaxing activity was potentiated by superoxide dismutase. It was inhibited by hemoglobin, hydroquinone, or methylene blue but not by catalase or mannitol. Preincubation of polymorphonuclear neutrophils with aspirin, quinacrine, metyrapone, or AA-861 had no effect on the relaxing activity of SRF. L-Arginine dose dependently increased the relaxing activity of SRF, whereas NG-monomethyl-L-arginine (L-NMMA) decreased it, and this decrease was reversed by L-arginine. In contrast, neither L-arginine nor L-NMMA affected the relaxing activity of NDRF. These data suggest that SRF may represent a relaxing factor that is synthesized de novo from L-arginine.

Animals↗

PubMed1991

Human serum albumin inhibits prostacyclin production by endothelial cells: the relation of the inhibitory activity to sulfhydryl groups in albumin.

Human serum inhibited calcium ionophore-induced production of prostacyclin by cultured bovine aortic endothelial cells. The inhibitory fraction was purified from serum by anion-exchange and Blue-Sepharose affinity chromatography. The molecular weight of the purified substance was 67k dalton as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It was identified as human serum albumin by N-terminal amino acid sequence analysis. Human serum albumin was separated to two forms by high-performance liquid chromatography: mercaptalbumin (SH type) and nonmercaptalbumin (SS type). Both types of albumin inhibited the conversion of arachidonic acid to prostaglandin H2 in a dose-dependent manner without affecting phospholipase A2 or prostacyclin synthetase. This inhibition was more potent in mercaptalbumin than in nonmercaptalbumin. These results suggest that the conversion between mercaptalbumin and nonmercaptalbumin may play an important role in the modulation of prostacyclin synthesis by endothelial cells.

Adenosine Diphosphate↗

PubMed1991

Decreased sulfhydryl groups of serum albumin in coronary artery disease.

We hypothesized that oxidative processes in myocardial tissues initiated by ischemia also cause the same kind of changes in blood proteins and lead to oxidation of sulfhydryl groups (SH). To test this hypothesis, the ratio (%MA) of mercaptalbumin to total albumin (= mercaptalbumin + nonmercaptalbumin) and the total SH contents of serum were measured in patients with coronary artery disease. There was a positive correlation between %MA and total SH contents and both values were reduced in proportion to the severity of the coronary artery disease. Furthermore, these values were lower early hours after the onset of acute myocardial infraction than 4 weeks later. These results support our hypothesis, and may provide a basis for the administration of agents which can counteract oxidative stress in order to protect myocardium in patients with coronary artery disease.

Adult↗

PubMed1991

Bovine brain coated vesicles contain guanine nucleotide regulatory proteins.

Binding of [3H]guanosine triphosphate (GTP) with a high affinity was found to be present in the coated vesicle fraction prepared from bovine cerebral cortex. The binding was saturable and displaced by 1 microM of GTP, guanosine diphosphate and guanosine 5'-(3-O-thio)triphosphate. Incubation of the vesicles with islet-activating protein and [32P]NAD resulted in ADP-ribosylation of a 39,000-41,000-dalton polypeptide. Antibodies to the alpha-subunit of stimulatory guanine nucleotide regulatory proteins (G-proteins) immunoblotted 52,000- and 45,000-dalton polypeptides. The results indicated that stimulatory and inhibitory G-proteins are contained in a fraction of the bovine brain coated vesicles.

Adenosine Diphosphate Ribose↗

PubMed1991

Immunohistochemical studies on ontogeny of bovine lymphoid tissues.

Developing lymphoid tissues of bovine fetuses ranging from 70 to 270 days of fetal age were examined by histological and immunohistochemical procedures. In the peripheral blood, surface membrane immunoglobulin bearing cells (B-lymphocytes) and sheep red blood cell rosette forming cells (T-lymphocytes) had already appeared by 70 days of fetal age. In the lymph nodes intracytoplasmic IgM positive cells appeared at 90 days of fetal age. The cells positive for IgG appeared at 150 days of fetal age and IgA positive cells appeared at 180 days of fetal age. The spleen contained intracytoplasmic immunoglobulin positive cells at almost the same time as those in the lymph nodes. In the ileocecal region, IgM positive cells and IgG positive cells were present at 180 days of fetal age and IgA positive cells were present at 210 days of fetal age. The tonsils contained IgM positive cells and IgG positive cells at 240 days of fetal age. In the thymus, terminal deoxynucleotidyl transferase positive cells appeared at 90 days of fetal age.

Animals↗

PubMed1991

Immunocytochemical localization of synaptophysin on the smooth-surfaced tubular membranes present in nerve terminal and preterminal areas in the rat cerebellar cortex.

The distribution of synaptophysin, a major protein of the synaptic vesicle membrane, was immunocytochemically examined in the rat cerebellar cortex. A monoclonal antibody against synaptophysin recognized the epitope to be present in the presynaptic membranous structures including synaptic vesicles, presynaptic membrane, coated vesicles, and vacuoles of endocytotic origin. In the nerve terminal as well as preterminal areas, the antibody labeled the smooth-surfaced tubular membranes which were located in the relatively interior parts of these areas and consistent in size and appearance with the short tubules comprising the thinner parts of the axonal reticulum. However, the antibody did not stain the short tubular membranes, though similar in appearance to the above, which existed right below the axolemma in the preterminal and nerve terminal areas. The results are discussed with special reference to the precursor membrane compartments of synaptic vesicles.

Animals↗

PubMed1991

[The elevation of serum iron level with oral administration of medroxyprogesterone acetate (MPA) in patients with breast cancer].

The elevation of serum iron level was noted in six out of 45 patients with breast cancers who were treated by medroxyprogesterone acetate (MPA) in Kinki University Hospital. Those six patients were not found to be involved in hemolysis and liver dysfunction during the treatment. The level of serum iron was demonstrated 205-338 micrograms/dl in the blood after MPA treatment. This elevation of serum iron level was not related with another anti-cancer agents. There was no observed serious complication with high level of serum iron. This is the first report of the elevation of serum iron level following MPA therapy for the patients with breast cancers.

Aged↗

PubMed1991

[Spinal artery aneurysm associated with dural AVM of the posterior fossa].

The incidence of an aneurysm of the spinal artery is extremely rare. Only several cases have been documented previously. Herewith, the authors present a patient with a ruptured aneurysm of the anterior spinal artery associated with dural AVM of the posterior fossa. A 51-year-old male had a sudden onset of occipital headache and left shoulder pain. Lumbar puncture revealed bloody CSF. Angiography showed a saccular aneurysm, filling from the anterior spinal artery and dural AVM of the posterior fossa. Aneurysmal neck clipping and cauterization for nidus of dural AVM was performed successfully through suboccipital craniectomy with laminectomy of C1 and C2. The authors reviewed the literature and discussed the features of the aneurysm of a spinal artery.

Aneurysm↗

PubMed1991

[A report of a transsphenoidal operation during pregnancy for a pituitary adenoma].

A 29-year old female, in her second pregnancy, complained of headache, nausea, vomiting and left blurred vision. In spite of improvement of these symptoms in the second postpartum, she complained of recurrent symptoms in her third pregnancy. CT and MRI showed a pituitary adenoma with hematoma. It was totally removed using the transsphenoidal approach during pregnancy at 8 months. The histological examination revealed that the tumor was an acidophilic adenoma with a hemorrhagic change. A healthy baby was born at the full term after the operation. Our transsphenoidal operation during pregnancy was only the second such attempt reported in our collected literature. The management of the pituitary tumor during pregnancy is discussed.

Adenoma↗

PubMed1990

Malignant Sertoli and Leydig cell tumour in a boar.

A rare case of Sertoli and Leydig cell tumour was investigated in a 6-month-old boar. The neoplasm was found in the right testis and had metastasized to the liver, spleen, kidneys and diaphragmatic peritoneum. Metastatic nodules were also present in the tissues near the right testis and some neoplastic cells were present in the superficial inguinal lymph node. The neoplastic cells exhibiting severe pleomorphism were divided into Sertoli and Leydig cell types, although in some sites, it was not possible to classify tumour cells clearly as Sertoli or Leydig in type. In the metastatic lesions there were anaplastic Sertoli cells with abundant collagen fibres. Some neoplastic Sertoli cells and a few neoplastic Leydig cells revealed cytoplasmic reactivity for testosterone. Ultrastructurally, the neoplastic cells were characterized by mitochondria with tubulovesicular cristae, smooth endoplasmic reticulum, membranous structures, lysosomes, lipofuscin granules or lipid droplets.

Animals↗