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Biomedical subjects

A Nishimura

Publications and source records attributed to A Nishimura.

At least 19 recordsLinked to original sources

Age-related decrease of serotonergic fibres and S-100 beta immunoreactivity in the rat dentate gyrus.

The age-related changes of serotonergic fibres and S-100 beta-positive astrocytes in the rat dentate gyrus were examined using immunohistochemistry. A significant reduction in the number of the serotonergic fibres and S-100 beta-positive astrocytes was observed throughout the dentate gyrus of the aged rat. A positive correlation was noted between the decrease of serotonergic fibres and S-100 beta-positive astrocytes in the aged rat dentate gyrus. These findings support the hypothesis that the age-related degeneration of serotonergic fibres in the dentate gyrus is caused by the decrease in serotonergic neurotrophic factor S-100 beta in the astrocytes.

Aging

Thyrotropin-releasing hormone in treatment of intractable epilepsy: neurochemical analysis of CSF monoamine metabolites.

The efficacy of thyrotropin-releasing hormone in children with intractable epilepsy was investigated and changes in cerebrospinal fluid monoamine metabolites were analyzed. The 18 patients had either West syndrome (12 patients) or Lennox-Gastaut syndrome (6 patients), which was intractable to antiepileptic drug therapy and to adrenocorticotrophic hormone. Thyrotropin-releasing hormone-tartrate was administered for 4 weeks. Before and after the thyrotropin-releasing hormone administration, cerebrospinal fluid was collected and analyzed for 5-hydroxyindoleacetic acid, kynurenine, homovanillic acid, and 3-methoxy-4-hydroxyphenyl glycol. The patients were classified into 3 groups, based on seizure frequency and electroencephalographic effects: cessation of seizures and seizure discharges (very effective; group A), reduction of seizures and/or seizure discharges (effective; group B), and no changes in frequency of seizures or discharges (not effective; group C). There were 6 patients in group A, 3 in group B, and 9 in group C. There were no significant differences in monoamine metabolites before and after the thyrotropin-releasing hormone therapy. A trial of thyrotropin-releasing hormone for the treatment of intractable epilepsy is warranted and further study is required on the mechanism of the antiepileptic action of thyrotropin-releasing hormone.

Child

Developmental changes in P300 wave elicited during two different experimental conditions.

Age-related correlations on auditory event-related potentials were studied using a task-relevant oddball paradigm in 175 normal subjects aged 4-21 years and age-related correlations in the "ignore" condition were studied in 108 normal subjects aged 1-21 years. In the ignore condition, subjects more than 4 years of age were instructed to read a book to divert attention from the auditory stimulus. From 4 to about 17 years of age, the latencies of task-relevant P300 in event-related potentials (ERPs) gradually shortened. In the ignore condition experiment, the P300 latency shortened progressively, but stabilized at about 12 years of age. Whereas P300 in the ignore condition likely corresponds to P3a described previously (passive attention), the conventional P300 wave corresponds to P3b (active attention). The findings indicate a developmental difference between the P3a and P3b potential.

Adolescent

[Preventive chemotherapy for residual liver after resection of hepatic metastasis from colorectal cancer].

We compared 12 cases treated with intra-arterial chemotherapy (group A), with 15 cases only undergoing the usual hepatectomy (June 1991-February 1995). Six cases in group A were H1, 4 were H2, and 2 were H3; 12 cases in group B were H1, and 3 were H2. In both groups, primary lesions were removed. All cases received high-dose intermittent 5-FU infusion (WHF) at 1,000 mg/m2 via a reservoir for 5 hours a week at the outpatient clinic. Cumulative survival rates for 1 and 3 years are 100% and 68.6%, respectively, in group A, and 58.7% and 25.2% in group B, which indicates the treatment outcome in group A was significantly better. Recurrence in residual liver was not found in group A except for one case whose tumor was unremoved, but it was found in 8 cases (53.3%) in group B up to this writing. CEA value after resection in group A was within the normal range except for one case with a local recurrence. It seems that intra-arterial 5-FU infusion chemotherapy for residual liver after resection of hepatic metastasis from colorectal cancer has a preventive effect on residual liver, and the improvement of the cumulative survival rate can be expected.

Aged

Clinical abnormalities in adults with pancreaticobiliary maljunction with and without bile-duct dilatation.

OBJECTIVE: To study clinical diseases associated with pancreaticobiliary maljunction with or without bile-duct dilatation. DESIGN: A retrospective study over 16 years. SETTING: A single university surgical service in Japan. PATIENTS: Thirty-three patients with pancreaticobiliary maljunction. MAIN OUTCOME MEASURES: Gallstones and cancer in patients with and without bile-duct dilatation. RESULTS: Twenty-five patients had dilatation of the bile duct, 8 did not. Seven (28%) of the 25 patients with bile-duct dilatation had gallstones compared with 1 (12%) of the 8 patients with no dilatation. Seven (88%) of the 8 patients with no dilatation had carcinoma (all of the gallbladder), but only 3 (12%) of the 25 patients with bile-duct dilatation had carcinoma (1 of the gallbladder, 2 of the bile duct). CONCLUSION: Prophylactic cholecystectomy is recommended for patients with pancreaticobiliary maljunction and no dilatation of the bile duct because of the high incidence of gallbladder cancer.

Adolescent

[The mechanism of cardiorespiratory arrest due to subarachnoid hemorrhage].

This report describes the clinical course of patients with sudden cardiorespiratory arrest (CRA) due to subarachnoid hemorrhage (SAH). We have seen fifteen patients of SAH that presented initially as CRA. All of them were diagnosed as SAH by CT scan. The patients were divided into two groups; one group (early DOA group) included 11 patients, who had been recognized as CRA within 60 minutes from the onset of SAH, the other group (late DOA group) consisted of 4 patients, who developed CRA more than 60 minutes after the initial onset. The major mechanism leading to delayed CRA in the late DOA group appeared to have been from brain stem herniation, but another mechanism appeared to be involved in sudden CRA in the early DOA group. Sixty percent of our patients with CRA due to SAH had a low serum potassium concentration, though hypokalemia was observed in only 4 out of 100 patients with CRA due to diseases other than SAH. These facts suggest that sympathetic hyperstimulation might result not only from stress but also from a disorder of the central autonomic nervous system. We speculate that the mechanism leading to early CRA after SAH appears to result from a disorder of the central autonomic nerve system.

Aged

Introduction of DNA into sea urchin eggs by particle gun.

We have applied the particle gun method, which was developed to introduce DNA into plant cells, to sea urchin eggs and have obtained excellent expression of the introduced DNA in the embryos. The expression can be normalized by concomitantly-introducing a reference construct. The method provides a new approach to quantitative analysis of cis-regulatory elements in sea urchin embryos.

Animals

Monoamine metabolites in the cerebrospinal fluid in infantile spinal muscular atrophy.

Analyses of tryptophan and tyrosine metabolites in cerebrospinal fluid were performed to examine an abnormality of the monoamine neurone system in severe infantile spinal muscular atrophy (SMA type I). The levels of 5-hydroxyindoleacetic acid and homovanillic acid were significantly lower than those in controls. Decreases in the concentration of 5-hydroxyindoleacetic acid and kynurenine seemed to be related to the severity of SMA type I. These results suggest that the monoamine neurone system may play a role in the pathophysiology of SMA type I.

Biogenic Monoamines

Two-color analysis of peripheral lymphocyte surface antigens in inherently healthy adults.

We studied 134 "healthy persons" with no past history of any serious or latent diseases, and observed differences in their 25 lymphocyte subsets by conducting two-color analyses using 12 useful combinations of dye-labeled monoclonal antibodies. CD4+Leu8+ cells and CD25+CD3+ cells were significantly higher in males than in females, whereas CD4+Leu8- cells and CD23+CD19+ cells were significantly higher in females. In comparison of the 25 lymphocyte subsets among four age groups, CD45RA-CD4+ cells and CDw29+CD4+ cells significantly increased with age, and CD8+ CD11b- cells and CD57-CD8+ cells significantly decreased with age. In females, helper T cells significantly increased and helper inducer T cells increased, while cytotoxic T cells decreased with age. These are important findings that should be considered in studies of immune function and autoimmune disorders.

Adult

The development of a pyogenic liver abscess following radical resection of cholangiocellular carcinoma with ligation of the right hepatic artery: report of a case.

We present herein the case of a pyogenic liver abscess developing from hepatic ischemia caused by resection of the right hepatic artery when a left hemihepatectomy with caudate lobectomy and extrahepatic bile duct resection was performed for cholangiocellular carcinoma. Postoperative cholangiography revealed communication between the abscess cavity and the intrahepatic bile duct. The liver abscess was successfully treated by percutaneous transhepatic drainage. Thus, breakdown of the intrahepatic bile duct due to ischemia may play an important role in the development of a pyogenic liver abscess following hepatic arterial occlusion.

Bile Duct Neoplasms

Extended central bisegmentectomy--an en bloc resection of hepatic segments 4, 5, 8 and 7: report of a case.

We herein present an example of an extended central bisegmentectomy in a patient with a large hepatocellular carcinoma. According to a magnetic resonance imaging study, the right hepatic vein was displaced and narrowed at its origin and a large inferior right hepatic vein was revealed. In this case, owing to the only slightly functional remaining hepatic reserve, an extended central bisegmentectomy was selected as the optimum treatment. The postoperative course was uneventful except for some bile leakage. Twelve months after operation, the patient is still alive and no sign of recurrence has been detected. The extended central bisegmentectomy is an en bloc resection of hepatic segments 4, 5, 7, and 8. When the large inferior right hepatic vein is present, segment 6 can be preserved even when the right hepatic vein is sacrificed at its origin.

Carcinoma, Hepatocellular

Identification of four metabolites of 3-(phenylamino)alanine, a constituent in L-tryptophan products implicated in eosinophilia-myalgia syndrome, in rats.

3-(Phenylamino)alanine (PAA), a contaminant found in L-tryptophan tablets, has been discussed as a possible cause of eosinophilia-myalgia syndrome (EMS). We administered PAA (100 mg/kg) by gastric gavage to Wistar rats to determine its distribution and metabolism. We developed a purification procedure, using Bond Elut SCX cartridges followed by high performance liquid chromatography (HPLC) in order to determine levels of PAA. The level of PAA in blood was 4.22 micrograms/ml at 5 h and urinary excretion was 21.7 micrograms for 5 h and 84.6 micrograms between 5 and 24 h. The amount of PAA in the contents of the large intestine at 5 h was 0.76 microgram, indicating poor transfer of PAA to the large intestine. However, the highest concentration of PAA was 12.3 micrograms/g in the brain, indicating the passage of PAA through the blood-brain barrier. In addition to detecting PAA in the blood and organs, we also detected four metabolites of PAA in urine. We used gas chromatography mass spectrometry to identify PAA in rat liver, as well as N-(hydroxyphenyl)glycine, N-phenylglycine, 3-(pheylamino)lactic acid, and 3-(hydroxyphenylamino)-lactic acid in rat urine. These results suggest that the degradation pathway of PAA is similar to that of phenylalanine.

Administration, Oral

Serial MRI in infantile bilateral striatal necrosis.

A 3-year-old girl with left hemiparesis suffered from bilateral paresis, motor rigidity, gait disturbance, axial hypotonia, dysarthria, apathy, and incontinence. After steroid therapy, mild improvement occurred, but muscle weakness, gait disturbance, and rigidity remained. Leigh encephalopathy was excluded on the basis of muscle biopsy and laboratory findings. Computed tomography and serial magnetic resonance imaging at an early stage revealed right-sided dominant lesions in the putamen and caudate nucleus and later bilateral striatal lesions, appearing as hyperintense signals on T2-weighted images and mixtures of hypo- and hyperintense signals on T1-weighted images. This is the first demonstration of serial magnetic resonance imaging findings in infantile bilateral striatal necrosis.

Basal Ganglia Diseases

Compressed air injury of the colon complicated by rhabdomyolysis: case report.

We present a case of traumatic injury of the colon by compressed air. Elevated levels of urinary myoglobin, creatinine phosphokinase, lactate dehydrogenase, and glutamic oxaloacetic transaminase indicating rhabdomyolysis were noted. In this type of injury, rhabdomyolysis related to acute peripheral circulatory failure may occur because of obstruction of venous return to the heart following a great increase in intraperitoneal pressure.

Adult

Experimental arthritis induced by continuous infusion of IL-8 into rabbit knee joints.

To determine the roles of IL-8 in inflammatory synovitis, examination was made of the results of continuously injecting human recombinant IL-8 into the knee joints of New Zealand while rabbits. Recombinant human IL-8 was infused continuously into the joint cavity at 75 ng/h for 14 days by a polypropylene catheter connected to a mini-osmotic pump implanted in each rabbit. Infiltration of inflammatory cells into joint cavity and histopathological changes in synovial tissue were examined at 7 and 14 days following the start of infusion. The continuous infusion of IL-8 for 14 days led to severe arthritis characterized by apparent erythema and joint pain, the accumulation of leucocytes, infiltration of mononuclear cells in synovial tissue, and marked hypervascularization in the synovial lining layer. IL-8 may be a factor which can contribute to the inflammatory process of chronic arthritis by mediating leucocyte recruitment and hypervascularization in inflamed joints.

Animals

Aberrant distribution of tyrosine hydroxylase and substance P in infants with brain-stem infarction.

The distribution of tyrosine hydroxylase (TH) and substance P (SP) was examined in the brain-stem of 4 infants with respiratory abnormalities associated with remote brain-stem or cerebellar infarction utilizing immunohistochemical methods. TH-immunoreactive cells and SP-immunoreactive fibers were found in and around the area of the infarction in the tegmentum, in amounts and sites different from that seen in controls. The aberrant localization of SP and TH may represent an altered repair process associated with resolution of the infarction and may be related to abnormal respiratory control or sudden death.

Brain Stem

Efficacy of thyrotropin-releasing hormone in the treatment of spinal muscular atrophy.

Children with spinal muscular atrophy were treated by the administration of thyrotropin-releasing hormone. In three infants with spinal muscular atrophy type I, thyrotropin-releasing hormone showed little efficacy, but in children with types II and III, there was improvement in motor function and electromyographic findings after the thyrotropin-releasing hormone therapy. Thyrotropin-releasing hormone has a neurotrophic effect on the spinal anterior motor neurons of spinal muscular atrophy patients and thus may be warranted for the management of spinal muscular atrophy.

Age of Onset