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Biomedical subjects

M Nishimura

Publications and source records attributed to M Nishimura.

At least 991 records · Page 55Linked to original sources
PubMed1991

[Autosomal recessive oculopharyngeal "muscular dystrophy"--clinical features and association with reduced activity of myophosphorylase].

We reported two cases of brothers demonstrating oculopharyngeal muscular dystrophy (OPMD). The cases had consanguineous parents and five healthy siblings, which suggested the autosomal recessive inheritance. The initial symptom was slowly progressive blepharoptosis with onset in the third decade. On examination, total external ophthalmoplegia was observed in both patients. Additionally, the elder, a 57-year-old man, exhibited dysarthria, dysphagia and muscular weakness with atrophy of the face, bilateral proximal upper limbs and diffuse lower limbs. The younger brother, a 55-year-old man, displayed muscular weakness and atrophy distributed in the face and four limbs. Muscle biopsy of both cases revealed rimmed vacuoles and spheroid bodies in the atrophic and normal-sized fibers. Biochemical study of the biopsy specimens of the elder brother disclosed the myophosphorylase activity reduced to about 40% of the normal value, although in the younger brother, that activity was normal. OPMD is usually inherited in the autosomal dominant mode, and autosomal recessive OPMD is rare. The onset age of our cases was younger than that of the autosomal dominant OPMD. There were some differences in the clinical manifestation between the presented cases, which could be interpreted as phenotypic variation. The elder brother was thought to be associated with McArdle's disease.

Blepharoptosis↗
PubMed1991

Clinicopathological and histochemical studies of linitis plastica type gastric cancer with special reference to early gastric cancer in the region of the fundic gland.

In this study, early gastric cancer in the region of the fundic gland was found to occur predominantly in women. Many lesions of this type were identified in the posterior wall of the middle portion of the stomach. Histologically, the lesions were classified as poorly differentiated carcinomas in all cases of early cancer. On the other hand, in 9 patients with cancer of linitis plastica type having IIc lesions (less than 2.0 cm in diameter) located in the region of the fundic gland, the tumor focus was also in the posterior wall of the middle portion of the stomach. Giant folds were present diffusely in all other portions of the gastric mucosa in these latter cases. These cases also had diffuse infiltration of cancer cells into the submucosa, muscle layer and extraserosal regions. Histologically, the lesions were classified, in all cases of linitis plastica type, as poorly differentiated carcinomas including signet ring cells. Acid mucopolysaccharides (AMPS) and sialic acid were histochemically detected in the interstitial tissues of early gastric carcinomas and linitis plastica type gastric cancers. The AMPS digestion rates were higher for early cancer tissue. The present results support the hypothesis that early gastric cancer in the region of the fundic gland may occur in conditions favorable to tumor growth and may develop into cancer of linitis plastica type.

Adult↗
PubMed1991

Radiation-induced myeloid leukemia in C3H/He mice and the effect of prednisolone acetate on leukemogenesis.

We found that the incidence of spontaneous myeloid leukemia in C3H/He male mice was less than 1%, but it could be increased considerably by total-body X irradiation. The induction of myeloid leukemia was seen to increase after doses from 0.47 Gy (3%) to 2.84 Gy (23.9%), and then decrease after a dose of 4.73 Gy (13.6%). The administration of prednisolone acetate (synthesized glucocorticoid) after irradiation resulted in a significant increase in the incidence of myeloid leukemia from 23.9 to 38.5% after a dose of 2.84 Gy; however, corticosterone, a glucocorticoid secreted by cells, did not have such an enhancing effect.

Animals↗
PubMed1991

Adamantinoid basal cell carcinoma. An ultrastructural study.

We describe an adamantinoid basal cell carcinoma that has developed in the mucocutaneous border of the upper lip. An ultrastructural study disclosed three types of cells that were morphologically distinct in the tumor nest. Cells of the first type were basically the same as those of ordinary basal cell carcinoma. Cells of the second type showed varying degrees of cytoplasmic content loss in a worm-eaten pattern and seemed to consist of degenerating cells. Cells of the third type possessed a well-developed rough endoplasmic reticulum filled with medium electron-dense fine substance, which was also seen in the extracellular space. In relationship with the histochemical findings, and based on the histogenesis of adamantinoid basal cell carcinoma, we propose that subpopulations of tumor cells undergo spontaneous degeneration and that the spaces of such disappearing cells are refilled with products containing glycosaminoglycans secreted by another subpopulation of the tumor cells.

Basal Cell Carcinoma↗
PubMed1991

[A clinical study on pulmonary tissue uptake of flomoxef].

Based on the results of a study on pulmonary tissue uptake of flomoxef (FMOX), a new antibiotic agent, in 45 patients undergoing thoracotomy, the following conclusions were drawn: 1. Immediately preoperative 1 hour-drug infusion of 1 g FMOX led to maximum serum concentration (averaging 42.4 micrograms/ml) 1 hour later, with a half-life of its beta phase of 1.26 hours. 2. Normal lung (alveolar) tissue concentration was Cmax 17.98 micrograms/g with its ratios to serum peak value being 31.8, 27.1, 22.2, 9.4, 5.9 and 5.0% at 1, 2, 3, 4, 5 and 6 hours later, respectively. 3. Bronchiolar tissue concentration was Cmax 31.91 micrograms/g, with its ratios to serum peak value being 27.8, 19.3 and 10.1% at 2, 3 and 4 hours later, respectively, indicating its good bronchiolar intra-tissue transition. The above results suggested the usefulness of FMOX for both the treatment of respiratory infections and the prevention of postoperative infections.

Adolescent↗
PubMed1991

[Analysis of dysanapsis in healthy twins and sons of patients with chronic obstructive lung disease].

Pulmonary function tests and tracheal cross-sectional area (X-SA) measured on chest roentgenograms were analyzed in 72 healthy pairs of twins and in 34 healthy sons of patients with chronic obstructive lung disease. In the twin study, genetic influence was positive on most pulmonary function tests, including VC, FEV1/FVC, V25, but not so on X-SA. The ratio of X-SA to VC, which represents dysanapsis, had no relation to sex nor height. However, the ratio of X-SA/VC showed marked sex-associated differences, when expressed as a function of VC, and had a negative correlation with VC both in men and women. The ratio of X-SA/VC was significantly lower in sons of patients with COPD than in normal controls, which was caused by significantly larger VC in the former group. The relatively low ratio of tracheal size to lung size may partly explain the susceptibility to the possible future development of COPD in those subjects.

Adolescent↗
PubMed1991

[Anesthesia for cesarean section in patients with fetal anomaly].

Twenty-two cases of Cesarean section due to fetal anomaly diagnosed prenatally were reviewed in terms of the anesthetic managements. In 6 cases, diazepam 0.3 mg.kg-1, which provides fetal anesthesia for surgery scheduled immediately after birth, was administered intravenously to the mothers with/without fentanyl (2 general anesthesia and 4 regional anesthesia). The diagnosis of their fetuses was congenital diaphragmatic hernia, congenital cystic adenomatoid malformation of the lung, gastroschisis or omphalocele. No fetal anesthesia was performed in the other 16 cases (15 spinal anesthesia and 1 general anesthesia). Seven of their fetuses were diagnosed as hydrops. Since the general condition of the diseased newborn is known to be deteriorated after receiving various stress and aerophagia, fetal anesthesia in Cesarean delivery has the advantage of stress reduction and prevention of aerophagia. When the newborn is considered to need immediate neonatal resuscitation or intensive care including surgery, fetal anesthesia may be a choice of anesthetic technique.

Anesthesia, Obstetrical↗
PubMed1991

[Chemical burn caused by povidone-iodine].

Povidone-iodine (PVP-I) is a widely used antiseptic because of its low toxicity and high germicidal effect. A one-year-old boy who had undergone Nissen's fundoplication developed a chemical burn on his back postoperatively. The lesion was exposed to the surgical sheet immersed with a large amount of 10% PVP-I solution for 4 hours. Patch test with PVP-I (small aluminum chamber keeps a wet paper with PVP-I) revealed positive response in the patient. The same patch tests were performed in 17 volunteers. Sixteen subjects showed positive and one negative, while direct painting of a small quantity of PVP-I on skin without the chamber produced negative responses. This may indicate that prolonged exposure to wet PVP-I is harmful. It is important to use PVP-I carefully for the prevention of contact dermatitis.

Burns, Chemical↗
PubMed1990

Cloning and nucleotide sequence of cDNA for retinochrome, retinal photoisomerase from the squid retina.

The Rhodopsin-retinochrome system is essential for the visual photoreception of molluscs. cDNA coding for retinochrome of the squid (Todarodes pacificus) was cloned and the nucleotide sequence has been determined. The sequence (2.1 kb) covers the whole coding region of 903 bp. The deduced primary sequence suggests that retinochrome contains seven transmembrane spanning domains. The homology with bovine rhodopsin and the possible retinal binding site are also discussed.

Amino Acid Sequence↗
PubMed1990

[Experimental studies on the effects of insulin on central regulation of blood pressure].

It has been widely revealed that an insulin-like immunoreactive substance (ILI) is distributed in the brain, particularly in the hypothalamus and circumventricular areas where it is supposed that the balances of water and electrolytes are regulated. Although the insulin synthesis of the brain has not been clarified, the existence of ILI in the brain is clearly demonstrated, and ILI may play some important physiological roles on blood pressure regulation as well as feeding behavior. Taking notice of the Na(+)-K+ ATPase activating action of insulin, we aimed to investigate the central cardiovascular effects of insulin using rats, in comparison with the endogenous digoxin-like immunoreactive substance (DLI), which exists in the same sites of ILI, inhibits Na(+)-K+ ATPase activity, and increases blood pressure. When rats were fed high-salt diets for 4 weeks, hypothalamic and pituitary contents of ILI decreased significantly compared to those of rats on a regular diet. Intracerebroventricular (i.c.v.) infusion of insulin lowered the femoral arterial pressure and decreased the heart rate significantly in both urethane-anesthetized and conscious rats, and inhibited the renal sympathetic activities in urethane-anesthetized rats. Intravenous infusion of the same amounts of insulin, however, influenced neither blood pressure nor heart rate. Simultaneous i.c.v. infusion of insulin abolished the elevation of both blood pressure and heart rate produced by i.c.v. infusion of hypertonic saline. The increase in the plasma DLI was also abolished significantly. Inhibiting central sympathetic nerve activities and DLI secretion from the hypothalamus, cerebral insulin may effect the central regulations of blood pressure, particularly in salt-loading conditions.

Animals↗
PubMed1990

Human T lymphotrophic virus type I may not be associated with multiple sclerosis in Japan.

To study the possible involvement of human T lymphotrophic virus type I (HTLV-I) or a related retrovirus in Japanese cases of multiple sclerosis (MS), we first performed a Western blot analysis with purified Ag of HTLV-I. Ten out of 31 MS patients (32.2%), 19 of 66 patients (28.8%) with other neurologic diseases, and 2 of 64 healthy blood donors (3.1%) had antibodies reactive with Ag corresponding to the group-specific Ag (gag) proteins (p15, p19, p24) on their sera. There were no significant differences between MS and other neurologic diseases concerning the patterns and the frequency. Second, we tried to establish T cell lines from PBMC of 22 MS patients with crude IL-2 without accessory cells, because HTLV-I-infected T cells can be immortalized in a high ratio under those conditions. Only one T cell line (MS-14C), however, could be maintained in long term culture. MS-14C and cultured T cells for 3 to 5 wk derived from MS patients were examined by Southern blot analysis under both stringent and low stringent conditions with HTLV-I as a probe. No HTLV-I related bands could be detected. By polymerase chain reaction examination, we also could not detect HTLV-I provirus genome in the fresh PBMC from 20 MS patients, although some of them had gag-reactive antibodies. Our data do not favor the hypothesis of HTLV-I or an HTLV-I-related human retrovirus in the etiology of MS.

Antigens, Viral↗
PubMed1990

The inhibitory effect of probenecid on renal excretion of famotidine in young, healthy volunteers.

Effects of coadministration of probenecid on pharmacokinetic behaviors of famotidine, an H2-receptor antagonist, after oral administration, were studied in eight young, healthy volunteers. They received an oral 20 mg dose of famotidine with and without coadministration of oral 1500 mg doses of probenecid. The mean area under the serum famotidine concentration-time curve up to 10 hours was increased by coadministration of probenecid from 424 +/- 19 (SEM) to 768 +/- 39 ng.hr/ml. The mean urinary excretion rate of unchanged famotidine, the mean amount of unchanged famotidine excreted in urine up to 24 hours and mean renal clearance were decreased by coadministration of probenecid. The mean tubular secretion clearance of famotidine was decreased from 196.2 +/- 21.4 to 22.0 +/- 4.2 ml/min. These data suggest that probenecid, which is a classical inhibitor of renal tubular secretion of organic anions, inhibits the renal tubular secretion of famotidine, which exists partly in a cationic form under physiological pH conditions.

Adult↗
PubMed1990

Anticholinergic action of quinidine sulfate in the rabbit atrioventricular node.

Anticholinergic action of quinidine sulfate was electrophysiologically studied by recording spontaneous action potentials and membrane current of the rabbit atrioventricular node. In the presence of 0.1 mumol/l carbachol, the spontaneous activity of the atrioventricular nodal preparations was markedly inhibited, whereas subsequent addition of 1, 5 and 20 mumol/l quinidine restored automaticity in a concentration-dependent manner. In some preparations, quinidine at concentrations of 5 mumol/l and higher slowed the spontaneous activity by its direct membrane action even in the presence of carbachol. The dose-response curve for acetylcholine action on the spontaneous firing frequency showed that one molecule of acetylcholine bound to one muscarinic receptor of the atrioventricular node cell (Hill coefficient = 1.2). A parallel shift of this curve towards higher acetylcholine concentrations was observed at 0.03, 0.1 and 0.3 mumol/l but not at 1 and 3 mumol/l quinidine, suggesting a noncompetitive antagonism of quinidine against acetylcholine. Voltage clamp experiments revealed that 5 mumol/l quinidine reduced the slow inward current, hyperpolarization-activated inward current, and delayed rectifying K+ current, through its membrane actions. Quinidine at this concentration almost completely suppressed the acetylcholine-activated K+ current, which showed a relaxation phenomenon. Hence, the direct blockage of the acetylcholine-activated K+ current by quinidine was considered responsible for the anticholinergic action of this drug. We conclude that quinidine is a non-specific ionic channel blocker that inhibits all the membrane currents in the atrioventricular node including the acetylcholine-activated K+ current.

Action Potentials↗
PubMed1990

Electrophysiologic actions of aprindine in rabbit atrioventricular node.

Aprindine hydrochloride is a potent antiarrhythmic agent against various atrial and ventricular tachyarrhythmias. To elucidate its pharmacological actions in the atrioventricular node, electrophysiologic experiments were conducted by applying microelectrode and voltage clamp methods to small preparations of the rabbit atrioventricular node. At a concentration 1 mumol/l, aprindine decreased the spontaneous firing frequency, maximal rate of depolarization, action potential amplitude, and take-off potential (P less than 0.05, n = 7). The spontaneous and rate-controlled action potential durations at 50 and 100% repolarization were prolonged by aprindine. Voltage-clamp experiments using the double microelectrode method revealed that aprindine blocked the slow inward current (Isi) in a voltage-dependent manner with a dissociation constant of 10 mumol/l and Hill coefficient of 0.8. The steady-state inactivation curve for Isi was shifted toward more negative potentials by 2.5 +/- 0.9 mV (P less than 0.05, n = 5) without a significant change in the slope factor. This finding suggests that aprindine has a higher affinity for inactivated slow inward (or Ca2+) channels than for resting channels. Aprindine caused use-dependent block of Isi, a result consistent with the drug's slow dissociation from inactivated Ca2+ channels. The delayed rectifying K+ current (IK) tail obtained on repolarization from +10 mV to -60 mV was significantly decreased from 15.4 +/- 2.4 to 6.8 +/- 1.4 nA (P less than 0.01, n = 6) and the deactivation time constant significantly increased by 20.7% (P less than 0.01, n = 6). The steady-state activation curve for IK was shifted in the hyperpolarized direction by 6.9 +/- 2.9 mV, suggesting a potent voltage-dependent block of this current by aprindine. The hyperpolarization-activated inward current (Ih) was decreased from 14.4 +/- 5.4 to 12.0 +/- 5.5 nA (P less than 0.05, n = 5). The transient outward and inward currents induced by 1 mumol/l acetylstrophanthidin were almost completely suppressed after the addition of 1 mumol/l aprindine. These results suggest that aprindine exerts a negative chronotropic action both by slowing deactivation of IK and by reducing Isi and Ih, and delays atrioventricular nodal conduction by reducing Isi and IK. These blocking actions of aprindine together with its inhibition of the transient outward and inward currents may explain its antiarrhythmic effects on the atrioventricular node.

Action Potentials↗