Biomedical subjects

K Nishiyama

Publications and source records attributed to K Nishiyama.

At least 19 recordsLinked to original sources

PubMed1992

The carboxyl-terminal region of SecE interacts with SecY and is functional in the reconstitution of protein translocation activity in Escherichia coli.

Genes encoding the C- and N-terminal regions of SecE were constructed and placed under the control of the tac promoter on plasmids. The C-terminal region of SecE (SecE-C) was sufficient for suppression of the secEcs phenotype, confirming the results of Schatz et al. (Schatz, P. J., Bieker, K. L., Ottemann, K. M., Silhavy, T. J., and Beckwith, J. (1991) EMBO J. 10, 1749-1757). SecE-C allowed the overproduction of SecY, and its overproduction was achieved when the tac-secY gene, on a plasmid, was induced, indicating that the C-terminal region is the site of interaction of SecE with SecY and that the interaction makes the two Sec proteins stable. SecE-C was purified and used with SecY for the reconstitution of protein translocation activity. SecE-C was active in the functional reconstitution. The SecE-C/SecY-dependent protein translocation absolutely required SecA and ATP as the native translocation reaction did. Quantitative analysis revealed that SecE-C was 50% as active as intact SecE. The N-terminal region of SecE (SecE-N) also suppressed in vivo the defect caused by the secEcs mutation. SecE-N was, however, inactive in the overproduction of SecY. A possible oligomeric structure of SecE is discussed.

Adenosine Triphosphate↗

PubMed1992

Temporary threshold shift of temperature sensation caused by vibration exposure.

The temporary threshold shift of temperature sensation due to vibration exposure was studied to clarify the significance of frequency and acceleration on it. The discrete frequencies of the vibrations tested were 32, 63, 125, 250 and 500 Hz, and the accelerations were at the level of 2, 4, 8 and 16 g. The threshold shift of warm sensation (TTSw) was markedly, but that of cool sensation was small and not significantly different from the control value. TTSw increased with a rise in the level of acceleration and was largest at 125 Hz among the frequencies examined. The most effective frequency among the vibrations tested for warm sensation was inferred to be lower than that for vibratory sensation. After exposure, TTSw or the increment of the neutral zone decayed exponentially but bounced slightly in the later period. These patterns of TTSw are similar to those of the vibration-induced TTS of vibratory sensation.

Adult↗

PubMed1992

Suppression of myoelectrical activity of gastric smooth muscle by endogenous gastric prostaglandin E2.

The myoelectrical activity of the gastric smooth muscle, recorded by a bipolar electrode placed at the gastric antrum in rats, could be recorded when the stomach was distended with 5 ml of physiological saline. This activity may be induced by a mucosal reflex and was inhibited both by atropine and by pirenzepine. Replacement of physiological saline with solutions of NaCl suppressed this myoelectrical activity. This suppression was dependent on the concentrations of NaCl in the solutions, from 0.3 to 1.0 M. Pretreatment with indomethacin (10 mg/kg, intravenous) completely prevented this suppression induced by different concentrations of NaCl solutions. Intragastric administration of 1.0 M NaCl in solution caused an increase in the levels of PGE2 in the gastric lumen. Intragastric administration of OU-1308, a synthetic derivative of PGE1, also suppressed the myoelectrical activity in a dose-dependent manner. It is concluded that the suppression of gastric myoelectrical activity by hyperosmolar NaCl may be attributable to the generation of endogenous PGE2 in the stomach.

Alprostadil↗

PubMed1992

Randomized, controlled study on adjuvant immunochemotherapy with PSK in curatively resected colorectal cancer. The Cooperative Study Group of Surgical Adjuvant Immunochemotherapy for Cancer of Colon and Rectum (Kanagawa).

A randomized, controlled trial of adjuvant immunochemotherapy with PSK (Kureha Chemical Industry Co., Tokyo, Japan) in curatively resected colorectal cancer was studied in 35 institutions in the Kanagawa prefecture. From March 1985 to February 1987, 462 patients were registered. Four hundred forty-eight of those patients (97.0 percent) satisfied the eligibility criteria. The control group received mitomycin C intravenously on the day of and the day after surgery, followed by oral 5-fluorouracil (5-FU) administration for over six months. The PSK group received PSK orally for over three years, in addition to mitomycin C and 5-FU as in the control group. At the end of February 1990, the median follow-up time for this study was four years (range, three to five years). The disease-free survival curve and the survival curve of the PSK group were better than those of the control group, and differences between the two groups were statistically significant (disease-free survival, P = 0.013; survival, P = 0.013). These results indicate that adjuvant immunochemotherapy with PSK was beneficial for curatively resected colorectal cancer.

Adjuvants, Immunologic↗

PubMed1992

A single serine:pyruvate aminotransferase gene on rat chromosome 9q34-q36.

It was found in our previous study (Oda et al., 1990. J. Biol. Chem. 265: 7513-7519) that in the rat two mRNAs encoding mitochondrial and peroxisomal serine:pyruvate aminotransferase (SPT/AGT) are formed from a single SPT/AGT gene through alternative transcription initiation in exon 1. In an attempt to analyze the mechanisms underlying this unique phenomenon, we have isolated genomic clones harboring the entire rat SPT/AGT gene. In the present study, the location of the rat SPT/AGT gene was determined to be in the q34-q36 region of chromosome 9 by fluorescence in situ hybridization. Southern blot analysis of rat genomic DNA revealed an allelic BamHI restriction fragment length polymorphism among three different inbred rat strains. These results indicated that a single copy SPT/AGT gene is located on chromosome 9q34-q36 in the rat genome. This locus has been assigned the gene symbol Spat.

Animals↗

PubMed1992

Glycosaminoglycans of trabecular meshwork and adjacent tissues of the rabbit eye.

Glycosaminoglycans (GAGs) extracted from the trabecular meshwork (TM) of rabbit eyes were analyzed by cellulose acetate electrophoresis and sequential enzymatic degradation, and compared with GAGs extracted from the adjacent tissues including the cornea, sclera, iris and ciliary body. The TM contained hyaluronic acid (HA), chondroitin 4- and/or 6-sulfate (CS), dermatan sulfate (DS), keratan sulfate (KS), heparan sulfate (HS) and an unidentified band of Alcian-blue-stained material which was resistant to degradation by the enzymes and chemicals used. The GAGs of the rabbit TM included: 13.9% HA, 31.6% CS, 47.1% DS, 4.6% KS and 1.2% HS, and were distinct from those of the cornea and the sclera.

Animals↗

PubMed1992

Glycosaminoglycans of organ-cultured rabbit trabecular meshwork.

The anterior segments of rabbit eyes were dissected into two types of corneoscleral explants: one a large, ring-shaped block of tissue from one eye and the other consisting of small blocks of tissue from the other eye which was dissected into 8 parts. Explants were cultured for up to 2 weeks. The glycosaminoglycan (GAG) profiles of the organ-cultured rabbit trabecular meshwork were then investigated and compared with respect to explant size. The results revealed: (1) similar trabecular GAG profiles in both sizes of explants, (2) trabecular GAG profiles obtained within the culture period came to resemble those of noncultured specimens and (3) incorporation of the radiolabels continued for up to 5 days, with 2 days sufficient for GAG analysis.

Animals↗

PubMed1992

[Age-related effects of gastroduodenoscopy on arterial oxygen saturation].

Although endoscopy is widely used for safe and accurate examinations of gastroduodenal disease cases, several investigators reported arterial oxygen desaturation occurring during endoscopy. Endoscopy-induced oxygen desaturation is hazardous because it increases the risk of cardiac arrhythmia. This study is designed to investigate whether gastroduodenal endoscopy causes remarkable oxygen desaturation in elderly patients in comparison with younger ones and to study whether nasal oxygen administration can prevent it. Forty-four patients over 61 years old and 37 patients younger than 60 were divided into two groups, to one of which 100% oxygen (2 l/min) was administered through nasal prongs. During endoscopy, blood pressure, pulse rate, and arterial oxygen saturation (SaO2) were recorded at one-minute intervals by a pulse oximeter. Intubation of the endoscope caused a transient drop in oxygen saturation both younger and older patients with greater drops in older subjects (1.7 +/- 0.4% in the young and 3.3 +/- 0.8% in the old groups). In the older groups, two out of 20 patients who had no oxygen administration showed a saturation decrease of over 7%. On the other hand, no younger subject showed such a large degree of oxygen desaturation. Oxygen administration effectively prevented the endoscopy-induced desaturation both in younger and in older patients. In summary, the results of this study suggested that older subjects had a greater decrease of oxygen saturation during gastroduodenofiberscopy and that oxygen administration is useful to prevent the endoscopy-induced desaturation.

Aging↗

PubMed1992

Radioactive cesium in dirt accumulations on the roof of buildings.

The concentrations of 137Cs and 134Cs in dirt deposits on the roofs of buildings are much higher than those in the surface of soil at ground level. Thus dirt on roofs concentrates radioactive cesium in fall-outs. The 137Cs concentration in dirt deposits on the roofs of older buildings is not consistently higher than that on the roofs of new ones, but the 137Cs/134Cs ratio is higher in deposits on older buildings constructed before the first half of the 1970s, and decreases exponentially with decrease in age of the buildings gradually reaching 1.9 +/- 0.2, the value in the air-borne dust at the time of the Chernobyl accident. From this relationship, the contribution of Chernobyl radioactivity to accumulated 137Cs was calculated as 32% on buildings constructed in 1962. The radioactive cesium concentrations in dirt deposits in gutters of private houses and on the roofs of university buildings in Japan were also determined.

Air Pollutants↗

PubMed1992

[A case of fibromuscular dysplasia presenting with Wallenberg syndrome, and developing a giant aneurysm of the internal carotid artery in the cavernous sinus].

A 25-year-old man developed Wallenberg syndrome (WS). At that time his carotid angiography was normal. When he was 28 years old, he suffered from retinal artery embolism in the left eye. At the age of 30 years, he had an acute onset of abducens nerve palsy in his right eye. The carotid angiography showed a giant aneurysm at the cavernous sinus portion in the right internal carotid artery. At his age of 38, the right oculomotor, trochlear and trigeminal nerves were involved. A vertebral angiography revealed a bead-like formation, and a diagnosis of fibromuscular dysplasia (FMD) was made. An intensive angiographic examination revealed many stenotic or dilated lesions in the carotid, vertebral, coronary, renal, and hepatic arteries. A sural nerve biopsy specimen revealed that the sural vein was involved. In Japan only one case of FMD presenting with WS is known. FMD should be under consideration as an underlying disease, when WS occurred in younger patients with few risk factors. In this patient an angiography revealed no abnormality in the cavernous sinus portion of the internal carotid artery, when he suffered from WS. However, eight years later he was proved to have a giant aneurysm in the cavernous sinus portion. In conclusion, we support the hypothesis that aneurysm may originate from angiographically normal arterial wall in FMD.

Adult↗

PubMed1992

[Comparison of treadmill exercise, handgrip, and cold-pressor tests: with particular reference to the effects on hemodynamics, respiratory gas exchange, and sympathetic nervous activity].

The treadmill test (TM), handgrip test (HG) and cold-pressor test (CP) are now frequently used clinically for multiple purposes. However, gas exchange analysis has not been a common procedure during HG. In particular, during CP, it has not been previously reported. Relationships between these 3 tests and blood pressure, heart rate (HR), respiratory gas exchange and the sympathetic nervous activity of normal subjects have not been reported, either. This study was undertaken to clarify these points. Symptom-limited TM was performed in 11 normal male subjects with a mean age of 45 +/- 8 yrs according to the Bruce protocol, with the HG using the weight-sustaining method (equal weight of 50% maximal voluntary contraction) for 3 min, and CP for 2 min. Systolic and diastolic blood pressures (Ps, Pd) were recorded; HR was measured every 30 sec, and gas exchange variables, such as oxygen uptake (VO2) and carbon dioxide production, were documented every 10 sec using an aereomonitor AE-280 (Minato Medical Science Co). In 10 of 11 subjects, concentrations of plasma noradrenaline (PNA) and plasma adrenaline (PAD) were measured at rest and at the times of peak values of the 3 tests. The peak values of Ps and HR were much higher during TM than during HG and CP (p < 0.01), while the peak values of Pd during HG and CP were higher than during TM (p < 0.01). The VO2 increased significantly for all of the 3 tests (TM: +781%, HG: +65%, CP: +20%), with the increment being the greatest during TM. Both PNA and PAD increased significantly for the 3 tests, with the increments of PNA and PAD being the greatest during TM. The percent change in PAD was more prominent during HG and CP than during TM. This tendency was not as clear for PNA as for PAD. There was no correlation of delta Ps and delta Pd between the 3 tests, but values of delta HR correlated partially. No significant correlations of peak VO2 were observed between the 3 tests. The peak PNA correlated between HG and CP (r = 0.77, p < 0.01), and the peak PAD correlated between TM and CP (r = 0.67, p < 0.05). In summary, numerous differences in hemodynamic and respiratory responses and in sympathetic nervous activation were observed in the 3 tests. When the 3 tests are undertaken, careful attention should be paid for their characteristics, discrepancies and limitations.

Adult↗

PubMed1992

[Anesthetic management of a hemophilia A carrier for palliative operation and radical repair of a cardiac anomaly].

We experienced the anesthetic management of a hemophilia A carrier for two palliative operations (left and right unifocalization) and radical repair of cardiac anomaly. The patient was a ten-year-old girl and her father had hemophilia A. She was diagnosed as tetralogy of Fallot, major aortopulmonary collateral arteries and pulmonary atresia. Laboratory findings showed prolonged bleeding time and activated partial thromboplastin time, and decreased levels of factor VIII activity of 26%. When she was eight and nine years old, she underwent unifocalization. At both occasions, excessive bleeding tendency continued into postoperative period. This time she underwent radical repair in which her bleeding tendency was successfully controlled by use of a usual dose of concentrated factor VIII for twice.

Carrier State↗

PubMed1992

[The effect of anticholinergic drugs on 123I-IMP SPECT in Parkinson's disease].

Several reports have suggested that anticholinergics have some associations with mental deterioration in Parkinson's disease (PD). We investigated the effect of anticholinergics on regional cerebral uptake of tracer in PD patients using N-isopropyl p-[I-123] iodoamphetamine SPECT. Sixteen pairs of region of interest (ROI) were located in the cortex, a pair in the basal ganglia, thalamus, and cerebellum. The size of each ROI was about 16 mm x 16 mm. Regional cerebral uptake ratio (rCUR) was calculated by the next equation: rCUR = (total count in an ORI)/(mean of total count in the cerebellar ROIs). The comparison consisted of two parts; (1) 7 PD patients (age 59-76 (65.4 +/- 6.7 mean +/- S.D.)) who had been on chronic anticholinergic therapy underwent SPECT and Wechsler Adult Intelligence Scale (WAIS) twice, for the first time when they were on anticholinergics and second a month after discontinuation of anticholinergics. All but two patients performed significantly better on WAIS after discontinuation than when they were on anticholinergics. The improvement was about 10 points in total IQ. (2) 11 PD patients (age 52-79 (64.5 +/- 8.6 mean +/- S.D.)) on chronic anticholinergic therapy including all but two patients mentioned above (group A) and 25 PD patients (age 52-88 (66.7 +/- 9.8 mean +/- S.D.)) not receiving anticholinergics (group B) also underwent SEPCT. In the comparison (1), at all but two ROIs was the mean rCUR higher after discontinuation than when they were on anticholinergics and the difference was significant at 10 ROIs out of 32 ROIs in the cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1992

[A case of progressive hemiatrophy with type 2 muscle atrophy in muscle biopsy].

We reported a case of progressive hemiatrophy, whose skeletal muscle biopsy revealed type 2 fiber atrophy. This patient, a 40-year-old woman, noticed left leg atrophy at the age of 39. She had a history of minor trauma of the left thigh at the age of 30. On admission, physical examination revealed atrophy of various parts of her left side of body, predominantly in the left leg. There was no dermatological or neurological abnormalities except these atrophies. Hematological and biochemical examinations were normal. EEG, EMG, nerve conduction studies and autonomic function tests were normal in either side of the body. MRI study showed reduced muscle bulk as well as subcutaneous fatty tissue especially in her left leg. Skeletal muscle biopsy of her left quadriceps femoris muscle revealed type 2 fiber atrophy and type 1 fiber predominance. However, no abnormality was found in the intramuscular nerves. We considered that type 2 muscle fiber atrophy was one of the cause of atrophy of this case.

Adult↗

PubMed1992

Gastroesophageal reflux after endoscopic injection sclerotherapy.

The effect of sclerotherapy of esophageal varices on the gastroesophageal reflux was studied. Gastroesophageal reflux was monitored by a 24-h pH-monitoring catheter introduced into the distal esophagus. The results of pH monitoring of 16 patients who underwent sclerotherapy were compared with those of 21 patients with untreated varices. Seven of the 16 treated patients showed high occurrence rates of gastroesophageal reflux comparable to those observed in cases with severe reflux esophagitis. In the untreated group, only one patient showed pathological reflux (there was a significant difference between treated and untreated groups; p less than 0.01). When the level of reflux was compared with factors that might influence sclerotherapy-induced gastroesophageal reflux, there was a positive correlation between the magnitude of reflux and amount of sclerosant injected paravariceally in the submucosal tissue (p less than 0.05). The results indicate that the paravariceal injection of sclerosant for the treatment of esophageal varix may cause pathological gastroesophageal reflux after sclerotherapy is completed.

Analysis of Variance↗

PubMed1992

[XYY syndrome associated with motor neuropathy].

We described a case of XYY syndrome associated with motor neuropathy. The case was a 27-year-old male, who had 47-XYY chromosome karyotype. His symptoms were distal dominant muscle weakness and muscle atrophy in his lower extremities without objective sensory disturbance. He had no mental retardation or family history of neurologic diseases. The electrophysiological and pathological examinations revealed that his symptoms were due to peripheral motor neuropathy (neuronal type). His motor neuropathy may be of sporadic type. There may be some relation in the pathogenesis between XYY syndrome and motor neuropathy, although in the literature, XYY syndrome with motor neuropathy had not been reported so far.

Adult↗

PubMed1992

Transient osteopenia of the hip joint in children.

Two pediatric cases of transient osteopenia of the hip joint are reported. Roentgenograms showed bone atrophy in the femoral head, the femoral neck, and the pelvis. Bone scintigrams showed a higher accumulation. At the follow-up study, osteopenia disappeared in both cases, however coxa magna was recognized in one case. The emphasis is on differential diagnosis from more severe disease, because the syndrome is characterized by spontaneous resolution.

Bone Diseases, Metabolic↗

PubMed1991

SecY is an indispensable component of the protein secretory machinery of Escherichia coli.

Using a reconstitution system for protein translocation, the involvement of SecY in the translocation of secretory proteins across the cytoplasmic membrane of Escherichia coli was studied. Anti-SecY antibodies raised against the N- and C-terminal sequences prevented the functional reconstitution of the translocation system. Depletion of SecY from the solubilized membrane preparation was performed by treatment with anti-SecY IgG, followed by removal of IgG with protein A-agarose. The SecY-depleted preparation was inactive as to functional reconstitution. However, reconstitution with it was demonstrated in the presence of a protein fraction, which was released from the anti-SecY immunoprecipitate upon addition of the SecY fragment used to raise the antibody. Reconstitution with the SecY-depleted membrane fraction was also demonstrated in the presence of a purified SecY preparation. OmpT proteinase specifically cleaved SecY in the solubilized membrane preparation. The cleavage was accompanied by a decrease in the reconstituted activity. Based on these findings we conclude that SecY is an indispensable component of the secretory machinery.

Amino Acid Sequence↗