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Biomedical subjects

S Uchiyama

Publications and source records attributed to S Uchiyama.

At least 109 records · Page 6Linked to original sources
PubMed1996

Cloning and sequencing of a 27.8-kb nucleotide sequence of the 79 degrees-81 degrees region of the Bacillus subtilis genome containing the sspE locus.

The nucleotide sequence of a 27830-bp DNA segment in the 79 degrees-81 degrees region of the Bacillus subtilis genome has been determined. This region contains 29 complete ORFs including the sspE gene, which encodes a small acid-soluble spore protein gamma and locates on the one side terminal of our assigned region. A homology search for the products deduced from the 29 ORFs revealed that nine of them exhibit significant similarity to known proteins, e.g. proteins involved in an iron uptake system, a multidrug resistance protein, a chloramphenicol resistance protein, epoxide hydrolase, adenine glycosylase, and a glucose-1-dehydrogenase homolog.

Amino Acid Sequence↗
PubMed1996

Microbial cyanide sensor for monitoring river water.

A microbial cyanide sensor using Saccharomyces cerevisiae for monitoring a river water is described. This sensor is based on the inhibition of S. cerevisiae's respiration by cyanide. This sensor is a reactor type flow system and composed of two oxygen electrodes and a reactor which contains S. cerevisiae immobilized beads. The S. cerevisiae's respiration activity is measured using the oxygen electrodes. The sensor showed a linear response in the range from 0 to 15 microM and maintained stable response for 9 days at ambient temperature. The sensor was optimized for the monitoring of river water and was applied to river water analysis.

Biosensing Techniques↗
PubMed1996

Histologic evidence of absorption of sequestration-type herniated disc.

STUDY DESIGN: The reactions to sequestrated disc fragments, which were removed surgically from 35 patients, were examined histologically. OBJECTIVES: To elucidate whether or not there is histologic evidence of absorption of sequestrated discs. SUMMARY OF BACKGROUND DATA: Spontaneous disappearance or diminution of lumbar herniated discs in the spinal canal has been recognized, and this could be a possible explanation for relief of symptoms without surgery. The mechanism of this phenomenon is unclear. METHODS: Sequestrated discs removed surgically from 35 patients were examined histologically. RESULTS: In 30 cases, neovascularization was observed at the periphery of the sequestrated discs. Many foamy cells (macrophages) were present in the vascularized areas. In addition, immunohistochemistry revealed that many spindle-shaped, fibroblast-like cells were positive for CD68, a marker of macrophages. No fibrous scar formation was observed in any region. CONCLUSION: These findings suggest that organization is not a main course for this type of herniated disc and that a kind of "absorption" process occurs predominantly in the healing stage.

Adult↗
PubMed1996

Characteristics of compensatory hypertrophied muscle in the rat: I. Electron microscopic and immunohistochemical studies.

BACKGROUND: Complex branched muscle fibers are frequently observed in the muscles of mdx mutant mice and/or in damaged muscles. To investigate whether the complex branched fibers were present in the compensatory hypertrophied muscles of rats, we examined the morphological changes in these muscles. METHODS: We examined the hypertrophied plantaris (PLA) muscle of the Wistar male rats, prepared by surgical ablation of synergistic muscles. The muscle was examined using three-dimensional analysis with scanning electron microscopy, immunohistochemical detection of proliferating cells using 5-bromo-2'-deoxyuridine (BrdU) and histological and histochemical characterization. Studies were performed at 48 hours, 2, 4, 6, 10, and 15 weeks after surgical preparation. RESULTS: The muscle hypertrophy ratio (muscle weight relative to the contralateral intact control side), gradually increased from 2 to 10 weeks, and the peak value (48.6%) occurred at the 10th week. The total number of fibers did not change significantly at any time interval. However, the number of branched muscle fibers increased significantly (P < 0.05) after 6 weeks, and accounted for about 2.5% of the total fibers at the 15th week. Most branched fibers showed complex features resembling the "anastomosing syncytial reticulum" described in myopathic animals. The fibers were observed mainly in the middle and distal portions of the PLA muscle. The proportion and distribution of proliferating cells in the entire PLA muscle corresponded with the distribution of the complex branched fibers. These results were also observed in muscle tissues prepared for histological and histochemical examination. CONCLUSIONS: The presence of a large proportion of complex branched fibers in a limited segment of the compensatory hypertrophied muscle suggests that this hypertrophy model represents a pathological and/or pathophysiological hypertrophy model rather than a normal physiological process.

Adaptation, Physiological↗
PubMed1996

Spinal tracts producing slow components of spinal cord potentials evoked by descending volleys in man.

Slow negative (N) and slow positive (P) waves are frequently produced in the posterior epidural space at the lumbosacral enlargement by epidural stimulation of the rostral part of human spinal cord. The production of these slow potentials are thought to be responsible for analgesia at the stimulated segment as well as below that level. In order to define the spinal tract which mediates these slow potentials, we stimulated directly or from the epidural space the dorsal, dorsolateral, lateral and ventral columns at the cervical or thoracic level, and epidurally recorded spinal cord potentials (des.SCPs) at the lumbosacral enlargement in 7 patients who underwent spine or spinal cord surgery. The des.SCPs recorded in the lumbosacral enlargement consisted of polyphasic spike potentials followed by slow N and P waves. At a near threshold level of stimulus intensity the slow N and P potentials were consistently elicited only by stimulation of the dorsal column. The slow waves were also produced by intense stimulation of other tracts, but remained significantly (P < 0.05 - P < 0.01) smaller than those evoked by dorsal column stimulation when compared at the same stimulus intensity. Moreover, the slow P wave could not be elicited even by intense stimulation (10 times the threshold strength for the initial spike potentials) of the ventral column. Thus, the results suggest that the slow N and P waves are mostly mediated by the antidromic impulses descending through the dorsal column.

Adult↗
PubMed1996

Cloning and sequencing of a 40.6 kb segment in the 73 degrees-76 degrees region of the Bacillus subtilis chromosome containing genes for trehalose metabolism and acetoin utilization.

In the framework of the international project aimed at the sequencing of the Bacillus subtilis genome, a 40.6 kb chromosome segment, which contains the tre locus, has been cloned and sequenced. This region (40 601 bp; 73 degrees-76 degrees on the genetic map) contains 38 complete ORFs and one partial one. Three ORFs, the closest to the hsdC locus, correspond to the treP, treA and treR genes encoding enzyme IITre, trehalose-6-phosphate hydrolase and the repressor of the tre operon, respectively. A homology search for the products deduced from the 39 ORFs revealed that 23 exhibit significant similarity to known proteins, e.g. proteins involved in acetoin utilization, deoxyribonuclease, methyladenine glycosidase, hydroxyisobutyrate dehydrogenase, multidrug resistance proteins, protein phosphatase, cyclic-nucleotide phosphodiesterase, 5'-nucleotidase and NADP(H)-flavin oxidoreductase. Based on the gene organization and the results of the homology search, it is predicted that YfjG, YfjH, YfjI, YfjJ and YfjK form an acetoin dehydrogenase system (acetoin regulatory protein, and acetoin dehydrogenase components/subunits E3, E2, E1 beta and E1 alpha respectively). yfkN, an extremely large ORF comprising 4386 nucleotides, seems to correspond to the fusion of the genes for 2',3'-cyclic-nucleotide 2'-phosphodiesterase and 5'-nucleotidase precursor.

Acetoin↗
PubMed1996

[Diagnosis of intracardiac thrombi by various imaging techniques and activation of platelets and coagulation-fibrinolysis in patients with cardioembolic stroke].

Recent epidemiological studies have suggested that 15 to 30% of all ischemic stroke is comprised of cardioembolic stroke. The presence of intracardiac thrombi might prove to be the most reliable tool when making a diagnosis of cardioembolic stroke, although not always easy to determine even with recent advanced technique. In this study, sensitivities to detect intracardiac thrombi of transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), cardiac-enhanced CT (CCT) and scintigraphy with indium-111-tropolone-labelled platelets (PSG) were compared, in order to provide a relevant guideline for the diagnosis of intracardiac thrombi in 83 patients suspected of cardioembolic stroke. Also studied was the correlation of intracardiac thrombi with activation of platelets and coagulation-fibrinolysis through performing various hemostatic tests in order to investigate their utility for the evaluation of in situ thrombosis or prothrombotic state in the heart chamber. Detection rates of intracardiac thrombi were 35% in TEE, 26% in CCT, 19% in PSG, and 11% in TTE. There was a significant difference in the sensitivity between TEE and TTE (p < 0.05). Left atrial thrombi were frequently detected in TEE (4 out of 5 patients) and CCT (7 out of 10), while they were found less in PSG (2 out of 4) an TTE (4 out of 10). Thrombi in the left appendage were visualized in 3 out of 3 by TEE, while only in 1 out of 3 by PSG, 1 out of 4 by TTE and 1 out of 4 by CCT. Left ventricular thrombi; CCT (3 out of 3), TTE (2 out of 3), PSG (1 out of 1); TEE was not performed since this technique could not be expected to provide high-quality images of left ventricular thrombi. Thus, left atrial thrombi were considered to be more sensitively detected by TEE and CCT, left appendage thrombi by TEE, and left ventricular thrombi by TTE and CCT. There was no patient in whom an intracardiac thrombus was visualized by PSG alone. On the basis of the results above, we propose the following guideline for the detection of intracardiac thrombi in patients presented with cardioembolic stroke. First, TTE and CCT appear to be relevant for screening tests because of simple and non-invasive techniques. These two tools might be sensitive enough to find left ventricular thrombi. Second, TEE should be recommended when a thrombus is suspected in the left atrium or appendage. Finally, PSG may be used to determine the activity of the thrombus, according to its necessity. Among the patients having intracardiac thrombi, frequently observed was the increase of beta-thromboglobulin, platelet factor 4, platelet lysis, thrombin-antithrombin III complex, D-dimer in 67%, 75%, 71%, 80% and 80%, respectively, as well as the shortening of platelet survival in 100%, while anrithrombin III was reduced in only 38%. In addition, when hemostatic abnormalities were compared between positive and negative groups of intracardiac thrombi, the shortening of platelet survival (p < 0.0001), the increase of platelet lysis, and the increase of D-dimer (p < 0.04) were more frequent in the positive group than in the negative group. These results indicate that the findings of activation of platelets and coagulation-fibrinolysis, except for the reduction of antithrombin III, especially the findings of platelet consumption and lysis as well as fibrinolysis activation are useful as sensitive parameters of in situ thrombosis or prothrombotic state, which may lead to the formation of intracardiac thrombi.

Adolescent↗
PubMed1996

Histologic changes in the disc after cervical spine trauma: evidence of disc absorption.

We examined the histologic changes in the disc in two cases of traumatic cervical disc herniation and compared it with previous histologic studies done in degenerative disc herniations. Differences in the absorption of herniated cartilage endplate and annulus fibrosus are also discussed. The herniated disc material was surrounded by fibrovascular tissue. Vessels in this fibrovascular tissue were seen to continue into the annulus fibrosus but not into the endplate. Scattered cartilage fragments and macrophages in the fibrovascular tissue were localized around the margin of the disc. The herniation produced a visible defect in the injured intervertebral disc. On serial sections, the amount of herniated annulus fibrosus appeared to be smaller than the defect produced in the annulus fibrosus of the injured disc. However, the herniated endplate seemed to be the same size as the defect produced in the endplate of the injured disc. Fibrovascular tissue formation, vessel infiltration into annulus fibrosus, and the presence of peripheral macrophages suggest marginal absorption. The cartilage fragments are probably remnants of disc tissue produced during the process of absorption. These findings are similar to that seen in degenerated herniated discs and suggest an absorptive process. Absorption of the annulus is more significant than absorption of the endplate.

Accidental Falls↗
PubMed1996

Genetic characterization of protein C deficiency in Japanese subjects using a rapid and nonradioactive method for single-stand conformational polymorphism analysis and a model building.

We studied the molecular basis of protein C deficiency in 28 Japanese families including 4 asymptomatic families. Two showed a decreased level of function with a normal antigen concentration consistent with type II protein C deficiency and the remaining 26 showed type I deficiency with decreases in both function and antigen level. All the exons and intron/exon junctions of the protein C gene were studied using a strategy combining polymerase chain reaction (PCR) amplification and rapid nonradioactive single-strand conformational polymorphism (SSCP) analysis. The PCR-amplified fragments with aberrant migration on SSCP analysis were sequenced. We identified 11 missense mutations, 1 nonsense mutation, 2 neutral polymorphisms, 1 frameshift deletion, 1 inframe deletion, and 1 splice site mutation. We also identified two different rare mutations in the 5'-untranslated region in the protein C gene that may be responsible for the phenotype. Of these molecular defects, ten were novel. From the results of genetic analysis of 47 Japanese families with protein C deficiency reported in this and previous studies, Phe139Val and Met364Ile substitutions and a G8857 deletion were only found in Japanese subjects and seem to be a founder effect. In contrast, Arg169Trp and Val297Met substitutions, both occurring at CG dinucleotides, were commonly observed in not only Japanese but also Western populations, indicating that these are hot spots for mutation in the protein C gene. These molecular defects were found in 22 families in total, accounting for 47% of Japanese families with protein C deficiency. The structural models of the second EGF and protease domains of activated wild-type and mutant human protein C suggest a possible substrate binding exosite on two loops; one from amino acid position 349 to 357 and the other from position 385 to 388, both of which are close to each other in the three-dimensional model.

Amino Acid Sequence↗
PubMed1996

[A case of neuroborreliosis with unilateral radiculoneuropathy and elevated serum antibodies for Borrelia garinii and Borrelia afzelii].

A 24-year-old male patient was admitted to our hospital because of dysesthesia and weakness of the right leg. Six weeks before admission he traveled to southern China. A week later he noticed multiple papules with itching on his right leg that were suspected to be insect bites. Four days later numbness of the right leg developed. Then he began to limp because of the leg weakness. Two weeks before admission severe pain in the right leg developed. On admission neurological examination revealed hypesthesia, muscle weakness and atrophy, areflexia, radicular pain and Lasègue sign of the right leg, and patchy hypesthesia of the left leg. The cranial nerves were intact, and meningeal signs were negative. Complete blood counts and serum biochemistry were unremarkable except for eosinophilia and mild elevation of IgE. A test for antinuclear antibody was positive. Cerebrospinal fluid was normal. Nerve conduction study and sural nerve biopsy showed multifocal severe axonopathy. Although antibody for Borrelia burgdorferi sensu stricto was negative, antibodies for B. garinii and for B. afzelii were positive in serum immunoblotting. Neurological symptoms improved after administration of intravenous ceftriaxon following oral doxycycline. In Japan, this is the second case of neuroborreliosis not due to B. burgdorferi sensu stricto. To test antibodies for B.garinii and for B. afzelii is recommended in patients with suspected neuroborreliosis.

Adult↗
PubMed1995

Activation of the estrogen receptor through phosphorylation by mitogen-activated protein kinase.

The phosphorylation of the human estrogen receptor (ER) serine residue at position 118 is required for full activity of the ER activation function 1 (AF-1). This Ser118 is phosphorylated by mitogen-activated protein kinase (MAPK) in vitro and in cells treated with epidermal growth factor (EGF) and insulin-like growth factor (IGF) in vivo. Overexpression of MAPK kinase (MAPKK) or of the guanine nucleotide binding protein Ras, both of which activate MAPK, enhanced estrogen-induced and antiestrogen (tamoxifen)-induced transcriptional activity of wild-type ER, but not that of a mutant ER with an alanine in place of Ser118. Thus, the activity of the amino-terminal AF-1 of the ER is modulated by the phosphorylation of Ser118 through the Ras-MAPK cascade of the growth factor signaling pathways.

Amino Acid Sequence↗
PubMed1995

Posterior migration of cervical spinal cord between split laminae as a complication of laminoplasty.

STUDY DESIGN: This is a case report. OBJECTIVE: To focus attention on a possible neurologic complication of laminoplasty. SUMMARY OF BACKGROUND DATA: An iatrogenic spinal cord lesion developed after laminoplasty as an operative complication of unknown cause. METHODS: Two patients had iatrogenic damage to the spinal cord from an unknown cause after laminoplasty of the cervical spine, but recovered soon after an additional laminectomy. They were evaluated with regard to the mechanism of damage and prevention. RESULTS: The spinal cord damage occurred when the spinal cord migrated posteriorly and deformed between the split laminae at the apex of the lordosis, where the maximum posterior displacement of the spinal cord was achieved. CONCLUSION: This damage was caused by a relatively narrower canal resulting from the split laminae of the apex of the adjacent laminae.

Aged↗
PubMed1995

Method for the measurement of friction between tendon and pulley.

An experimental system was developed that allows direct measurement of friction at the tendon-pulley interface, and the results were interpreted by use of a theoretical model for friction of a cable around a fixed pulley. Validation experiments were conducted with a nylon cable around a nylon rod. One end of the cable was connected to an actuator via a load cell, and the other end was connected to a 4.9 N load via a similar load cell. The cable was passed around the nylon rod and then pulled toward the actuator. Tests were performed at five different arcs of contact. The friction forces, as measured by the difference between two load transducers, were compared with those determined for a theoretical model and were used for calculation of the friction coefficient. The measurement system then was used to study the friction force between the flexor digitorum profundus tendon and the A2 pulley on nine fresh frozen index digits. The method allows us to measure the direct interaction between the tendon and pulley and could be used to evaluate and compare procedures for tendon-pulley and pulley repair and reconstruction, as well as for the study of tendon-pulley friction in various pathological conditions.

Fingers↗
PubMed1995

Heterotopic gastric mucosa of the gallbladder.

A case of heterotopic gastric mucosa in the fundus of the gallbladder is reported. A 23-year-old man, who had been healthy and asymptomatic, visited our hospital because of abnormal findings in a liver enzyme test given during a routine health screening. Ultrasonography demonstrated a highly echogenic polypoid mass in the fundus of the gallbladder. The gallbladder mass was confirmed by both computed tomography and intravenous cholangiogram. After a 10-month follow up, laparoscopic cholecystectomy was performed. Intraoperative touch smear cytology of this lesion revealed class II cells. The surgical specimen revealed a 15 x 10 x 5 mm polypoid lesion in the fundus, with no gallstones in the gallbladder. Histologically, the polypoid lesion consisted of both fundic type and pyloric type gastric glands located in the mucosa of the gallbladder. In the literature, 42 cases of heterotopic gastric mucosa of the gallbladder have been reported, only 3 of which, including this present case, were found incidentally, with no apparent symptoms.

Adult↗
PubMed1995

Adenomyoma of the common hepatic duct.

A very rare case of adenomyoma of the common hepatic duct is described. A 54-year-old woman was admitted with impending obstructive jaundice secondary to adenomyoma of the common hepatic duct. Our impression, formulated from her clinical presentation, endoscopic investigations, and biochemical and radiological findings, was a cancer of the proximal common hepatic duct. The patient was treated successfully by combination surgical resection and hepaticojejunostomy. Despite our obtaining an intraoperative frozen section, final histological examination was required to confirm the diagnosis. The patient remains well 16 months postoperatively. A survey of the world literature revealed that this is the second report of adenomyoma occurring in the common hepatic duct.

Adenomyoma↗
PubMed1995

Absolute and relative growth of rat skeletal muscle.

Change in body weight and lower hindlimb length as physical properties, muscle weight and length as whole-muscle properties, and fiber numbers, diameters, and numbers of proliferating cells as intramuscular properties, were measured in 2- to 60-week-old Wistar male rats. Results showed that the rapid increase in muscle weight (muscle mass) in the postnatal "growing phase" depended on the longitudinal and transverse growth. The increase in muscle length is due to longitudinal growth of muscle fiber, which may be derived from an increase in the number of sarcomeres. The increase in muscle girth depends on the increase of individual fiber diameter (muscle fiber hypertrophy) and fiber numbers (hyperplasia). The remaining increase in muscle mass in the "steady phase" (after the 10th week) is caused entirely by transverse growth, depending mainly on the muscle fiber hypertrophy (but may include increase of connective tissues). In conclusion, to study the effects of exercise and/or various overloads on muscle hypertrophy or hyperplasia, especially in the case of the plantaris muscle in Wistar rats, they should be 10-30 weeks old, and over 300 g in body weight, because in this period their characteristics remain most constant.

Animals↗