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Biomedical subjects

N Shibata

Publications and source records attributed to N Shibata.

At least 163 records · Page 9Linked to original sources
PubMed1997

Frontal lobe epilepsy with secondarily generalized 3 Hz spike-waves: a case report.

We report a case of frontal lobe epilepsy with bursts of 3 Hz spike-wave, often dominant in the left frontal lobe, that sometimes developed into a secondary bilateral generalization. This patient was a 69-year-old male with a history of epileptic seizures that began 3 months following a head injury at the age of 17. His seizures occurred two or three times a day, but after medication the frequency was halved. The seizures began with a feeling of heaviness of the head, accompanied by myoclonus at both angles of the mouth. Consciousness was clear for most of the seizures, which ranged from several seconds to many minutes. When seizures lasted for longer than 10 minutes, a temporary generalization accompanied by a loss of consciousness was sometimes observed. Neurological tests and cranial MRI yielded no abnormal local findings. The secondary generalized seizure seen in this case is the so called "secondary bilateral synchrony (SBS)." We succeeded in making an EEG recording of the bilateral generalization of a seizure discharge originating in the left frontal lobe, which until now has not been done. This case is direct proof that a primary frontal focus can give rise to SBS.

Aged↗
PubMed1997

A predictive model for area under the concentration versus time curve of cyclosporin A using several routine monitoring results in renal transplant patients.

We created a predictive model for the area under the concentration versus time curve (AUC) of cyclosporin A (CsA) using routine monitoring results, and examined its clinical utility. Based on 48 clinical time courses accumulated from renal transplant patients, the AUC predictive model was created. An estimate of the AUC0-8 (integrated from time zero to 8 h) was then given as follows: AUC0-8 = 5673.1 x log(TL) + 9342.8 x log(OB) + 64.1 x Dprd x 869.4 x DTK - 168.9 x HCT - 161.2 x SCr - 11.3 x GPT + 3.0 x PL - 588.6 x SEX - 24794.5. In this model, the AUC0-8(ng.h/ml) is given as a function of the CsA through levels (TL, ng/ml), obesity (OB, %), daily dose of prednisolone (Dprd, mg/d), donor type of kidney (DTK), hematocrit (HCT, %), serum creatinine (SCr, mg/dl), glutamate-pyruvate transaminase activity (GPT, IU/l), plasma lipids (PL, mg/dl) and sex distinction (SEX). The Statistical significance of the multiple regression was p < 0.00001 (R2 = 0.862, n = 48), and the day after transplantation, neither the administered oral dose of CsA, or the patient's age had any contribution to the regression. The predictive performance of this model was almost equal to that of the existing method which used 3-point data on the concentration versus time curve. In clinical adaptation for renal transplant patients, the steady-state concentration of CsA (Css) based on the AUC0-8 predictive model was significantly decreased during acute gastroenteritis or before acute rejection, whereas nephrotoxicity was increased, even though CsA trough levels were within a normal therapeutic range (100-200 ng/ml). These findings suggest that the created AUC0-8 predictive model using routine monitoring results, i.e., the trough level of CsA, biochemical tests, a daily dose of predorinsolone (PRD), and basic patient information, is convenient as a monitoring device for CsA therapy, and is satisfactory in clinical practice.

Adult↗
PubMed1997

A case of arrhythmogenic right ventricular dysplasia with left and right ventricular hypofunction in an elderly subject--long-term follow-up.

A 72-year-old man was admitted with palpitations caused by sustained ventricular tachycardia. He had been followed for 27 years, with admissions on 7 occasions, on account of ventricular tachycardias, atrial fibrillation, and congestive heart failure. Electrophysiologic examination detected 2 points of origin of ventricular tachycardia in the right and left ventricles. During the examination a myocardial infarction led to death. At autopsy, most areas of the right ventricle and the left ventricular apex were found to have been replaced by fatty tissue, pointing to severe fatty infiltration into the myocardium. Thus, this patient represented a unique cause of arrhythmogenic right ventricular dysplasia (ARVD) with severe fatty degeneration causing progression of ARVD. It is important that a diagnosis of ARVD is made carefully and rigorously in elderly subjects.

Aged↗
PubMed1997

[Influence of sleep apnea on nocturnal blood pressure].

In the present study, we subjected 65 patients to overnight monitoring and continuous nocturnal blood pressure measurement in order to assess the influence of sleep apnea on the circulatory system. Thirty-one patients were compared before and after surgery. The severity of sleep apnea was classified by Apnea Hypopnea Index (AHI), the duration of exposure to low-level oxygen (calculated as the desaturation time: DT), and increment of blood pressure. Before surgery, a significant correlation was noted between the DT and blood pressure changes. Therefore, this index was considered useful for assessing the influence of sleep apnea on nocturnal blood pressure. After surgery, improvement of AHI was greater than 50% in 19/31 patients (61.3%), and this result was almost the same as described in the literature. The improvements in DT and BP change were greater than 50% in 21/31 (67.7%) and 14/31 (45.2%), respectively. With regard to severity before surgery, AHI was > or = 50 and DT was > or = 40% in 10 and 18 patients, respectively. Nineteen patients had BP changes > or = 40 mmHg. After surgery, 1,5, and 2, patients, respectively, still showed these values. Thus, a beneficial effect of surgery was demonstrated.

Adult↗
PubMed1997

[Three cases of thymic hyperplasia associated with hyperthyroidism].

We encountered three cases of thymic hyperplasia associated with hyperthyroidism. Case 1 was in a 35-year-old woman; a chest CT scan showed an anterior mediastinal mass and right-sided pleural effusion, which suggested the presence of a thymoma Case 2 was in a 21-year-old man who complained of palpebral ptosis and also had myasthenia gravis (Osserman type I). Case 3 was in a 47-year-old woman; a chest CT scan showed thymic hyperplasia and mediastinal lymphadenopathy. In all cases, anti-thyroid medication was given first, because of the associations with hyperthyroidism. Moreover, in cases 1 and 2 no tumor was found, and only hyperplasia was detected in the thymus, although both patients underwent extended thymectomy. Furthermore, surgery was not effective against the hyperthyroidism (anti-thyroid medication could not be withdrawn or reduced). In cases 2 and 3, thymic hyperplasia, as seen on chest CT scans, resolved as thyroid function was normalized by anti-thyroid medication. The pretracheal lymphadenopathy seen in case 3 also resolved. Thymic hyperplasia may have been a result, not a cause, of hyperthyroidism. When we encounter patients with thymic masses and hyperthyroidism, we should give anti-thyroid medication and observe the thymus for some time before resorting to surgery.

Adult↗
PubMed1997

[Complication of reservoir hepatic artery infusion chemotherapy and additional treatments].

In 54 patients who underwent hepatic artery infusion chemotherapy for hepatic tumors at our hospital between January 1990 and December 1996, we investigated the complications of this therapy and the therapeutic techniques following its discontinuation. The arterial infusion was discontinued in 36 of the 54 patients; 13 due to death (mean survival period: 15.7 months), and 23 in whom occlusion of the reservoir, etc. made it impossible to use arterial infusion (mean period of use: 13.8 months), and the minimum duration of use was 41 days and maximum duration of use 992 days. The most common complication of the reservoir hepatic artery infusion was reservoir occlusion (14.8%). Another serious complication was reservoir deviation outside the blood vessel in two patients; deviation in to the gastric lumen in one case and intraperitoneal deviation in the other. Four hepatocellular carcinoma patients, in whom it became impossible to use the reservoir due to its occlusion, underwent re-hepatectomy. Three of them survived for more than two years following supplemental local therapy, including subarterial injection, TAE, PEIT, microwave tumor coagulation (MTC). Of four patients with colon cancer metastasizing to the liver, one could undergo re-hepatectomy, one received subarterial injection, and two have survived without relapse. Two of three patients with breast cancer underwent systemic chemotherapy and endocrine therapy successfully, while the third one underwent subarterial injection and TAE, and is still under observation. Hepatic artery infusion should sometimes be discontinued owing to complications caused by various factors. Even if it becomes impossible to use the reservoir, local therapeutic techniques, including re-hepatectomy, TAE, PEIT, MTC, etc., may be performed in some patients. These findings suggest that it is necessary to review the interdisciplinary treatment so as to be appropriate to the primary disease.

Aged↗
PubMed1997

[A case of stage IVb gastric cancer effectively treated by neoadjuvant chemotherapy and total gastrectomy with no residual tumor (R0)].

PA 72-year-old man visited our hospital complaining of body-weight loss and appetite loss. The upper gastrointestinal series and gastrointestinal fibroscopy disclosed a Borrmann 3 type gastric cancer. Laparoscopic examination revealed peritoneal dissemination (P2). Continuous intravenous administration of 5-FU (500 mg/day) for three weeks and drip infusion of CDDP (10mg/day) five days per week every three weeks was given as neoadjuvant chemotherapy. This course was carried out twice. Then laparoscopic reexamination revealed complete disappearance of disseminated lesions of the peritoneum, and total gastrectomy with R0 was done. Histopathological finding of the resected specimen showed significant effects of the neoadjuvant chemotherapy. The patient has been doing well with keeping good performance status (PS) 0 for one year and seven months after first diagnosis.

Adenocarcinoma↗
PubMed1997

Role of QT interval prolongation in the creation of spiral wave type reentry.

The inducibility of reentry was compared for four QT patterns in a heart conduction simulation model. Local (L) and gradual (G) QT prolongation models are more susceptible to reentry induction than the no (N) QT prolongation model (reentry induced episodes for N, L, and G numbered 90, 120, and 122, respectively). This increased vulnerability was diminished when the QT interval was prolonged at all simulation sites (reentry induced episodes for the diffuse QT prolongation model, D model, numbered 82). Decreased QT dispersion might be important for the prevention of reentry induction regardless of whether the QT interval is increased.

Action Potentials↗
PubMed1996

Tranilast suppresses the vascular intimal hyperplasia after balloon injury in rabbits fed on a high-cholesterol diet.

Intimal hyperplasia is a serious problem after percutaneous transluminal coronary angioplasty. In this study, we assessed the effect of tranilast on vascular intimal hyperplasia after balloon injury in rabbits fed on a high-cholesterol diet. In this animal model, intimal hyperplasia more severe than that in rabbits fed on a normal diet was observed. In addition, medial thickening and lipid deposits in both media and intima were also noted. These findings indicate that balloon injury caused intimal and medial hyperplasia and that this hyperplasia was accelerated by the high cholesterol load. Tranilast (300 mg/kg) significantly decreased the intimal area, medial area, and stenosis ratio, and increased the luminal/total area ratio, in the cholesterol-fed rabbits. These results suggest that tranilast may be useful for prevention of restenosis after percutaneous transluminal coronary angioplasty of patients, including those with a clinical risk of hypercholesterolemia.

Animals↗
PubMed1996

Anaerobic crystallisation of an isopenicillin N synthase.Fe(II).substrate complex demonstrated by X-ray studies.

Isopenicillin N synthase (IPNS) was cocrystallised with ferrous sulphate and its substrate, delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine (Aad-Cys-Val). Vital to the successful procedure was the maintenance of a rigorously anaerobic environment. Hanging-drop vapour-diffusion crystallisation experiments, using lithium sulphate as the precipitant produced three crystal forms. Form I crystals, with a plate habit, diffracted X-rays to at least 0.11-nm resolution at the European Synchrotron Radiation Facility and belong to the space group P2(1)2(1)2(1), with unit-cell dimensions a = 4.68, b = 7.15, c = 10.10 nm. Their asymmetric unit contains a single IPNS.Fe(II).Aad-Cys-Val complex with a solvent content of 38.5%. Form II crystals, with a hexagonal habit, diffract X-rays to at least 0.21 nm resolution at the European Synchrotron Radiation Facility and belong to the space group P3(1)21, with unit-cell dimensions a = 10.10, b = 10.10, c = 11.567 nm. Their asymmetric unit also contains a single IPNS.Fe(II).Aad-Cys-Val complex with a solvent content of 69.5%. Form III crystals, needles, do not show well-ordered diffraction. Although all three forms were initially produced in crystallisation experiments under identical conditions, appropriate micro and streak seeding allows selective crystallisation of form I or form II crystals. Extended X-ray-absorption fine-structure studies on a crystalline slurry of the form I crystals demonstrate the presence of an Fe-S(Aad-Cys-Val) bond length of 0.234 +/- 0.003 nm.

Anaerobiosis↗
PubMed1996

Molecular cloning and analysis of the 5'-flanking region of the rat PP1 alpha gene.

We have cloned an 8 kbp genomic fragment of 5'-flanking region of the gene encoding the catalytic subunit of rat protein phosphatase 1 alpha. Neither CAAT box nor TATA box was detected but a 300 bp high GC region containing nine Sp1 transcription factor binding sites is present immediately upstream of the translation start site, demonstrating that PP1 alpha is a housekeeping gene. Luciferase reporter assay showed that transcription of PP1 alpha is controlled at the high GC region.

3T3 Cells↗
PubMed1996

Structure and antigenicity of the mannans of Candida famata and Candida saitoana: comparative study with the mannan of Candida guilliermondii.

The chemical structure of the mannans of antigenic factor 9-expressing yeast, Candida famata and Candida saitoana, was analyzed by acetolysis and NMR. The structural study of the oligosaccharides and mannans using one- and two-dimensional NMR indicated that the mannan of C. saitoana contains a third type of beta-1,2-linked mannose unit. On the other hand, the mannan of C. famata does not contain any beta-1,2-linked mannose units. The mannan of C. saitoana gave two groups of beta-1,2 linkage-containing oligosaccharides by acetolysis. One contains one beta-1,2-linked mannose unit and the other contains two consecutive beta-1,2-linked mannose units at the nonreducing terminal. The inhibition of the reactivity of factor 9 serum on an enzyme-linked immunosorbent assay (ELISA) with these oligosaccharides indicated that the inhibition activity of the former oligosaccharide is 1/20 of that of the latter ones. The ELISA of the mannans of Candida guilliermondii, C. saitoana, and Saccharomyces kluyveri, all of which contain the third type of beta-1,2-linked mannose unit, indicated that Man(beta)1--> 2Man(beta)1-->2Man(alpha)1-->3Man(alpha)1-->works as the antigenic factor 9 but Man(beta)1-->2Man(alpha)1-->3Man(alpha)1--> weakly behaves as both antigenic factors 6 and 9. The epitope structures of the side chain oligosaccharides agreed well with that proposed from the 2D-HOHAHA spectra of the mannans. This result demonstrates the usefulness of the H-1 - H-2-correlated cross-peak pattern, which was reported in a preceding paper (Shibata, N., Akagi, R., Hosoya, T., Kawahara, K., Suzuki, A., Ikuta, K., Kobayashi, H., Hisamichi, K., Okawa, Y., and Suzuki, S. (1996) J. Biol. Chem. 271, 9259-9266) for the determination of the epitope structure of Candida mannans without any chemical fragmentation.

Acetic Acid↗
PubMed1996

Distribution of neurotensin-containing neurons in the central nervous system of the pigeon and the chicken.

Neurotensin is widely located in neurons of the central and peripheral nervous systems among mammalian species. To obtain a comparative evaluation, we examined the distribution of neurotensin-containing cell bodies and fibers in the central nervous system of the pigeon and the chicken. The pattern of localization of neurotensin immunoreactivity was similar in the two species. Abundant accumulations of neurotensin-containing cell bodies were found in the dorsolateral corticoid area, the piriform cortex, the parahippocampal area, the medial part of the frontal neostriatum, the lateral part of the caudal neostriatum, nucleus accumbens, the bed nucleus of the stria terminalis, ventral paleostriatum, the preoptic area, the ventromedial hypothalamic nucleus, the inferior hypothalamic nucleus, the infundibular hypothalamic nucleus, and the mammillary nuclei. Extremely dense networks of neurotensin-containing fibers were found in the pallial commissure, the lateral septal nucleus, the preoptic area, the periventricular gray around the third ventricle, the dorsalis hypothalamic area, the hypothalamic nuclei, the parabrachial nucleus, the locus ceruleus, and the dorsal vagal complex. Major differences of immunoreactivity between the two species were as follows. 1) The chicken neurohypophysis contained an extremely large accumulation of immunoreactive fibers, but there were few in the median eminence. The reverse was found in the pigeon. 2) The optic tectum in the pigeon contained immunoreactive cells and fibers in layers 2 and 4, but no immunoreactivity was seen in the chicken optic tectum. 3) The cerebellar cortex in the pigeon contained a small number of immunoreactive fibers, whereas that in the chicken did not. 4) The pigeon spinal cord contained immunoreactive neurons in the subependymal layer, but the chicken spinal cord did not. Our observations suggest the presence of a very wide network of neurotensin-containing neurons in the avian brain and spinal cord, which is also the case in mammals.

Anatomy, Artistic↗