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Biomedical subjects

K Ueda

Publications and source records attributed to K Ueda.

At least 613 records · Page 34Linked to original sources
PubMed1994

Amyloid beta protein-induced neuronal cell death: neurotoxic properties of aggregated amyloid beta protein.

The neurotoxic effects of soluble and aggregated synthetic amyloid beta protein (A beta P) have been investigated in rat primary cultures. Freshly solubilized beta(1-40) was neurotoxic not to immature, but to mature hippocampal neurons. On the other hand, aggregated beta(1-40) was neurotoxic to both. Neurotoxicity induced by aggregated beta(1-40) was 10-fold more potent than soluble beta(1-40) and was not prevented by substance P. The neurotoxicity of aggregated beta(1-40) to cultured neurons depended on the peptide concentration and the duration of exposure to it. Cerebral cortical and hippocampal neurons were significantly susceptible to aggregated beta(1-40) than cerebellar granular cells, and cultured astrocytes were not vulnerable to aggregated beta(1-40) even at high concentrations.

Amyloid beta-Peptides↗
PubMed1994

Comparison of the optimal culture conditions for cell growth and tissue plasminogen activator production by human embryo lung cells on microcarriers.

Optimization of culture conditions such as the dissolved O2 (DO) concentration, temperature and pH was attempted regarding both cell growth and the production of tissue plasminogen activator (TPA) in a microcarrier cell culture of human embryo lung cells. The growth rate was suppressed at a DO concentration below 30% saturation. From the pH range 7.2-7.6, both the specific growth rate and maximal cell concentration decreased. At a lower temperature than 37 degrees C, although both the specific growth rate and the maximal cell concentration decreased, the cell concentration was maintained for a longer time during the production period, high TPA productivity being maintained. As the optimal conditions for culture growth, a DO concentration of 30% saturation or over, temperature of 37 degrees C and pH of 7.4 are recommended. However, for TPA production after cell culture growth, the DO concentration should be in the range 20-30% O2 saturation, and the temperature and pH should be lowered to 33 degrees C and 6.8, respectively.

Cell Division↗
PubMed1994

Polyglucosan bodies in the brain of a cow.

Polyglucosan bodies (PGBs) in the brain of a 12-year-old Holstein cow exhibiting no signs of neurological abnormality were examined by light and electron microscopy and immunohistochemistry. PGBs were disseminated throughout the brain, especially in the pallidum, thalamus and cerebellum. Cow PGBs were found in the neuronal perikaryon and in the neuropil. These were round, slightly to severely basophilic, and were strongly positive for the periodic acid-Schiff reaction. The cow PGBs were immunoreactive for monoclonal antibodies raised against human polyglucosan. Electron microscopic analysis revealed that they were composed of branching filaments, glycogen granules and electron-dense material. These findings indicate that cow PGBs closely resemble human or canine PGBs in Lafora's disease and PGBs found in aged animals that have been reported previously.

Animals↗
PubMed1994

The association of the insulin resistance syndrome with impaired glucose tolerance and NIDDM in the Japanese general population: the Hisayama study.

To elucidate the risk factors for initiating glucose intolerance, the relevant factors were explored in a cross-sectional survey conducted in a sample population aged 40-79 years old selected from a Japanese community, Hisayama, Japan in 1988. A 75-g oral glucose tolerance test was used to classify 1,073 men (72.5% of the entire population in the same age range) and 1,407 women (80.5%) into normal, impaired glucose tolerance and diabetes mellitus groups. In all age and sex groups with normal glucose tolerance, the sum of fasting and 2-h post-load insulin values varied widely and demonstrated significant positive correlations with triglycerides, body mass index, waist-hip ratio, systolic and diastolic blood pressure, while it negatively correlated to HDL cholesterol (p < 0.05). Insulin resistance was presumed to develop in normal glucose tolerance subjects with hyperinsulinaemia. The sum of the insulin concentrations, triglycerides, body mass index, waist-hip ratio and blood pressure levels was significantly associated with impaired glucose tolerance in all age and sex groups after adjustment for age (p < 0.05) and was also related to diabetes in either all or some age and sex groups, respectively (p < 0.05). It was shown that glucose intolerance in the general population was associated with the factors related to insulin resistance. These cross-sectional data, therefore, support the hypothesis that insulin resistance is the primary defect in the development of glucose intolerance in the Japanese general population. However, a further prospective study is still needed in order to confirm this hypothesis.

Adult↗
PubMed1994

Single instillation of hydroxypropylcellulose-doxorubicin as treatment for superficial bladder carcinoma.

A single instillation of hydroxypropylcellulose (HPC)-doxorubicin (20 mg/20 ml) was performed in 20 patients with superficial bladder carcinoma. The therapeutic effect was assessed by cystoscopy at 14-30 days after the instillation, and the residual tumor tissue was resected by transurethral resection (TUR) when possible. The results obtained for the therapeutic effect were as follows: a complete response (CR), in 7 cases (35%); a reduction in size of more than 50% (partial response, PR), in 6 cases (30%); and a reduction of less than 25% in size (no change, NC), in 7 cases (35%). Combined intravesical instillation of HPC-doxorubicin and local hyperthermia using a Thermotron RF-8 was performed in 11 patients with recurrent superficial bladder carcinoma. The total number of treatment courses ranged from three to five per patient. The results obtained for the effect of this combined treatment were as follows: a CR, in 6 cases (54.5%); a PR, in 3 cases (27.3%); and NC, in 2 cases (18.2%). Therefore, the combination of intravesical instillation of HPC-doxorubicin and local hyperthermia was more effective against superficial bladder carcinoma than the single instillation of the chemotherapeutic agent alone.

Administration, Intravesical↗
PubMed1994

Effect of betaine on S-adenosylmethionine levels in the cerebrospinal fluid in a patient with methylenetetrahydrofolate reductase deficiency and peripheral neuropathy.

A 16-year-old Japanese girl with 5,10-methylenetetrahydrofolate reductase deficiency showed peripheral neuropathy. There were no significant responses to vitamin B6, vitamin B12 or folate, given alone or in combination. With the addition of betaine monohydrate, she has been free from gait disturbance and muscle weakness. The concentration of S-adenosylmethionine in cerebrospinal fluid, which was undetectable before receiving betaine monohydrate, increased to about the normal level 24 months after treatment with betaine monohydrate.

Adolescent↗
PubMed1994

Re-evaluation of classic senile plaques by three-dimensional analysis.

We evaluated the proportion of classic plaques among all of the senile plaques in four Alzheimer brains (frontal, temporal, occipital and hippocampal areas) by the usual method of two-dimensional analysis using a single methenamine silver-stained section and three-dimensional analysis using a set of serial sections. Three-dimensional analysis showed the number and percentage of classic plaques to be 2-5 times greater than those revealed by two-dimensional analysis. In the hippocampal area of one case, no classic plaques were found by two-dimensional analysis but three-dimensional analysis showed that some classic plaques were present. From these findings, it is suggested that three-dimensional analysis using serial sections is indispensable for subclassifying senile plaques.

Aged↗
PubMed1994

Inhibitors and activators of ADP-ribosylation reactions.

ADP-ribosylation reaction, that is the transfer of the ADP-ribose moiety of NAD+ to acceptor protein, is catalyzed by two classes of ADP-ribosyltransferases, i.e., poly(ADP-ribose) synthetase and mono(ADP-ribosyl)transferases. These two types differ not only in the number of transferring ADP-ribose units but also in the acceptor amino acid(s) and protein. Their inhibitors, particularly those of poly(ADP-ribose) synthetase, have been successfully employed in studies on biological functions of the enzymes and other related fields of research. Recently, we found many potent and specific inhibitors of poly(ADP-ribose) synthetase, and broadened their chemical as well as biochemical variety. More recently, we found several potent inhibitors of arginine-specific mono(ADP-ribosyl)transferases and activators of poly(ADP-ribose) synthetase.

ADP Ribose Transferases↗
PubMed1994

Influence of upright activity on plasma renin activity and aldosterone concentration in children.

Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured in 156 healthy infants and children under basal conditions of normal diet and recumbency. PRA and PAC were also evaluated during and after stimulation of the renin-angiotension-aldosterone system by postural change. Basal values of PRA significantly declined with increasing age. Postural change by standing up resulted in an increase of PRA and PAC in all age groups. The increment of PRA but not of PAC was greater in older than in younger children. Neither the basal nor the stimulated levels of PRA and PAC were influenced by sex, body weight, body surface area, serum sodium, serum potassium, creatinine, and 24-h urine secretion of sodium and potassium. Both PRA and PAC returned to the basal levels within 60 min after resuming recumbent posture.

Adolescent↗
PubMed1994

Predicting interferon therapy efficacy from hepatitis C virus genotype and RNA titer.

We classified 53 Japanese patients with chronic hepatitis C who were treated with natural interferon-alpha into genotypes and also tested the amounts of hepatitis C virus (HCV) RNA. The rate of the long-term complete response group, whose alanine aminotransferase levels remained within the normal range during the six months after therapy, was significantly higher (P < 0.01) in the type-III patients (4/5, 80.0%) than in type-II patients (4/43, 9.3%). For these long-term complete responders, the amounts of HCV RNA was less than 10(7) copies/ml serum in type-II patients, whereas two type-III patients with relatively high amounts of HCV RNA responded completely. These results confirm that the genotype of HCV is an important factor for predicting the response to interferon therapy. The amounts of HCV RNA can also predict its efficacy in type-II patients.

Adult↗
PubMed1994

Liposteroid against refractory pulmonary haemorrhage in idiopathic pulmonary haemosiderosis.

We describe two Japanese children with idiopathic pulmonary haemosiderosis (IPH), whose refractory haemorrhages were treated with an intravenous lipid emulsion containing dexamethasone (liposteroid). A 22-month-old boy and a 14-month-old girl have been observed with similar symptoms; periodic bouts of anaemia, reticulocytosis, diffuse infiltrates on chest X-ray and the finding of siderophages in sputum or gastric lavage fluid. The MRI of the lung was useful for the diagnosis. Methylprednisolone pulse therapy was successful in treating acute massive bleeding. Subsequent oral prednisolone could not prevent chronic recurrent haemorrhages. However, the intermittent administration of liposteroid (0.05 mg/kg/dose IV) led to a cessation of bleeding; the haemoglobin concentration rose to normal levels. This observation emphasizes the usefulness of liposteroid in the management of refractory IPH.

Dexamethasone↗
PubMed1994

Evaluation of hepatic proliferative activity in chronic liver diseases and hepatocellular carcinomas by proliferating cell nuclear antigen (PCNA) immunohistochemical staining of methanol-fixed tissues.

The proliferative activity of chronic liver diseases and hepatocellular carcinomas (HCCs) was studied by PCNA immunohistochemistry. Human liver tissues were obtained by surgical operation or needle biopsy, and PCNA was detected by immunohistochemistry. PCNA-labelling indices (PCNA-LIs) of methanol-fixed tissues corresponded with the incidence of S-phase cells previously reported, whereas paraformaldehyde-fixed tissues showed extremely high PCNA-LIs in all specimens. Therefore, methanol-fixed tissues were used for evaluation. The PCNA-LIs of the methanol-fixed tissues were: normal liver 0.78 +/- 0.38%, chronic persistent hepatitis 1.06 +/- 0.86%, chronic aggressive hepatitis 2A 1.01 +/- 0.50%, chronic aggressive hepatitis 2B 4.20 +/- 1.79%, inactive cirrhosis 0.81 +/- 0.49%, active cirrhosis 1.96 +/- 0.93%, HCC of Edmondson's type I 4.83 +/- 1.98%, type II 6.65 +/- 1.69%, and type III 38.7 +/- 30.6%. PCNA-positive cells showed little specific distribution; in periportal areas in chronic hepatitis, at the margins of pseudolobules in cirrhosis, and throughout the tumor in HCC. These findings indicated that proliferative activity increased during the progression of chronic hepatitis, but that it decreased at the stage of cirrhosis. In chronic liver diseases, the PCNA-LIs reflected hepatitis activity. HCC showed higher proliferative activity than liver cirrhosis, and the histological grade was correlated with the PCNA-LI.

Analysis of Variance↗
PubMed1994

How to deal with advanced cases of neuroblastoma detected by mass screening: a report from the Pediatric Oncology Study Group of the Kyushu area of Japan.

Since 1985, a nationwide program of mass screening (MS) for neuroblastoma has been underway for 6-month-old infants throughout Japan. As a result, the number of patients with stage I or II disease has obviously increased, and this has resulted in overall improvement of the prognosis for neuroblastoma. Some cases detected by MS were already in an advanced stage and have also had a good prognosis. In such cases, no definitive treatment protocol has been developed. Therefore, the authors investigated (1) the clinical and biological features of the advanced neuroblastoma cases detected by MS and (2) the best way to deal with such cases. The authors analyzed 94 cases of advanced-stage neuroblastoma registered in the Kyushu area (population, 15 million) between 1985 and 1990. Eighteen cases (16 stage III, 2 stage IV) were found by MS, and the others (23 stage III, 53 stage IV) were diagnosed clinically. The following results were obtained: (1) No N-myc amplifications were observed in cases detected by MS, whereas 16 of the 45 examined patients in the non-MS group had high amplifications of N-myc. (2) With regard to Shimada's classification, DNA content, and S-100 protein positivity, most of the advanced tumors found by MS showed characteristics indicating a good prognosis. (3) The 5-year survival rate for the non-MS group is less than 25%, whereas all of the patients whose tumors were detected by MS are alive, even after undergoing mild chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1994

The packaging signal in hepatitis B virus pregenome functions only at the 5' end.

When the hepatitis B virus (HBV) replicates, a full-size transcript of the viral genome, called pregenome RNA, is made and is selectively packaged into virus core particles. This selective encapsidation is dependent upon the presence of a specific cis-acting sequence called the packaging signal that is found at the 5' end of the pregenome RNA. Deletion analysis revealed that this packaging signal was located in a 70 bp stretch of nucleotides. Packaging defective virus genome containing the 70 bp packaging signal sequence at several locations, showed that the packaging occurs effectively only when the signal is located near the 5' end of the pregenome RNA. Packaging also occurred with a 2.4 kb viral RNA whose 5' region sequence was different from that of the pregenome RNA, but which has the packaging signal sequence inserted at the 5' region.

Base Sequence↗
PubMed1994

Behavior of Japanese tree frogs under microgravity on MIR and in parabolic flight.

Japanese tree frogs (Hyla japonica) were flown to the space station MIR and spent eight days in orbit during December, 1990. Under microgravity, their postures and behaviors were observed and recorded. On the MIR, floating frogs stretched four legs out, bent their bodies backward and expanded their abdomens. Frogs on a surface often bent their neck backward and walked backwards. This behavior was observed on parabolic flights and resembles the retching behavior of sick frogs on land--a possible indicator of motion sickness. Observations on MIR were carried out twice to investigate the frog's adaptation to space. The frequency of failure in landing after a jump decreased in the second observation period. After the frogs returned to earth, readaptation processes were observed. The frogs behaved normally as early as 2.5 hours after landing.

Adaptation, Physiological↗
PubMed1994

Spontaneous vascular mineralization in the brains of cows.

The frequency of occurrence and the characteristics of vascular mineralization in the brains of cows were studied. Mineralized lesions were found in the pallidal arteries in eight of 13 cows. They appeared as basophilic deposits in the arterial walls, were sheath-like or tubular in shape, and were accompanied by intimal oedema or fibrous thickening. The deposits were positive for periodic acid-Schiff, von Kossa's, alizarin red and Berlin blue stains. Elemental analysis revealed the presence of large amounts of phosphorus, calcium and zinc, as well as small amounts of iron, copper and sodium.

Animals↗
PubMed1994

Spontaneous aortic arteriosclerosis in layer chickens.

Aortas of 21 grower chickens (both sexes) aged 30-130 days and of 51 layer hens aged 500 days were examined histopathologically. Aortic sclerotic lesions were classified histopathologically into six stages. As early as 30 days, the abdominal aortas of growers had cellular-fibrous plaques that became more severe with advancing age. The majority of the abdominal aortas of all the 500-day-old layers had a conspicuous increase of collagen fibres, with atheromatous lesions in 23 (45.1%). These sclerotic changes were most severe in the distal aortas.

Animals↗