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Biomedical subjects

M Uchiyama

Publications and source records attributed to M Uchiyama.

At least 289 records · Page 16Linked to original sources

Reversal of daunomycin and vinblastine resistance in multidrug-resistant P388 leukemia in vitro through enhanced cytotoxicity by triterpenoids.

Examined in vitro were the effects of some triterpenoids from Panax (Araliaceae) and Glycyrrhiza (Leguminosae) spp. on the sensitivity to daunomycin (DAU) and vinblastine (VBL) of adriamycin (ADM)-resistant P388 leukemia cells (P388/ADM), which were resistant to multiple anticancer drugs. Quasipanaxatriol, 20(S)-protopanaxatriol, ginsenoside Rh2, and compound K greatly enhanced the cytotoxicity of the anti-cancer drugs in P388/ADM cells. The extent of enhancement was different among the triterpene compounds; the 4- to 46-fold increase in DAU cytotoxicity was observed in P388/ADM cells in the presence of non-toxic or marginally toxic concentrations of individual compounds, while those for VBL were in the ratios of 2- to 37-fold. The maximum increase in cytotoxicity was observed with 50 microM quasipanaxatriol; the resistance indices defined to be the ratios of the IC50 values for P388/ADM and P388 parental cells decreased from 79 to 1.7 and from 180 to 4.9 in the cases of DAU and VBL, respectively. The reversal of DAU resistance in P388/ADM by quasipanaxatriol could be explained by the effective accumulation of the drugs mediated by the DAU-efflux blockage.

Animals↗

Evidence for cdk5 as a major activity phosphorylating tau protein in porcine brain extract.

The major kinase capable of phosphorylating tau in a porcine brain extract was suggested to be a brain cdc2-like kinase, called cdk5. Tau protein components of microtubules assembled in the brain extract using ATP were phosphorylated to a higher level, and showed a slower electrophoretic mobility than those assembled with GTP. Most of this phosphorylation and electrophoretic mobility shift, that occurred in the brain extract incubated with ATP, were inhibited by butyrolactone I, a specific inhibitor of cdc2 kinase and cdk5. Further, butyrolactone I inhibited phosphorylation of tau exogenously added to the brain extract by approximately 70%. cdk5 purified from porcine brain decreased the electrophoretic mobility of dephosphorylated tau by in vitro phosphorylation of tau to the level present in microtubules polymerized with ATP. cdc2 kinase purified from starfish oocytes also phosphorylated tau and shifted its electrophoretic mobility to an extent greater than that obtained with cdk5. Western blot analysis showed that cdc2 kinase phosphorylated epitopes recognized by SMI31, 33, 34, and tau 1 antibodies in tau proteins , while cdk5 phosphorylated the site recognized by SMI33 (corresponding to phosphorylation at Ser235 in the longest human tau isoform) and partially phosphorylated the tau 1 site. Phosphorylation experiments performed on tau in brain extracts, in the presence of okadaic acid, suggested the presence of both okadaic acid-sensitive and -insensitive phosphatases acting on phosphorylated Ser235. Rat tau that was prepared immediately after decapitation showed a similar phosphorylation state to tau in microtubules polymerized with ATP, suggesting that tau is relatively phosphorylated in vivo.

4-Butyrolactone↗

Non-X histiocytoma, similar to fibrous histiocytoma, in an infant.

A case is presented of a female infant with an atypical histiocytoma. A gradually enlarging brown lesion was noted on the left side of the chest at the age of 2 weeks. Microscopic study of a biopsy revealed an ill-defined infiltration of spindle cells with indented nuclei. The tumor cells were positive for CD14, HLA-DR, lysozyme, alpha-1-antitrypsin and alpha-1-antichymotrypsin, and negative for CD1, CD3, CD8, CD10, CD19, CD68 and S-100 by immunohistochemistry. Electron microscopy demonstrated no distinct Birbeck's granules, but aberrant granules were seen in a small number of cells. At 7 months of age, a nodule with similar histologic features was noted in the nuchal region, but was incompletely resected. The patient remains recurrence-free at 36 months of age. This case is thought to be a benign form of non-X histiocytoma.

Diagnosis, Differential↗

Influence of parental obesity on the physical constitution of preschool children in Japan.

The objective of this study was to assess the influence of parental obesity on the physical constitution of preschool children. A total of 3187 children aged between 1-6 years and their parents were studied. A child whose per cent obesity (%OB; per cent overweight for age, height and sex) was greater than 15%, and a parent whose body mass index (BMI; kg/m2) was greater than the 95th percentile were defined to be obese (27.40 and 25.97 for a father and a mother, respectively). We found that the incidence of obesity in children with obese fathers (11.5%) was significantly higher than in those with non-obese fathers (6.2%), and a similar difference was obtained between children with obese mothers (14.5%) and with non-obese mothers (6.2%), respectively. The incidence of obesity in children was 6.0% if both parents were non-obese; this incidence rose to 22.7% if one parent was obese, and to 30.8% if both were obese. The %OB of children was more markedly correlated with the mothers' BMI (r = 0.219) than the fathers' BMI (r = 0.165). The %OB of children correlated significantly with fathers' BMI, but only from the age of 3-6 years, whereas mothers' BMI correlated from the age of 1-6 years. We conclude that parental obesity was of significance in determining the development of juvenile obesity even in the preschool period.

Body Constitution↗

Unique form of rickets with low serum 25-hydroxyvitamin D in two normally nourished children.

We present an unusual type of rickets involving two children: a 2 year old boy and a 15 month old boy, who presented with marked bowing of the lower extremities and bulging of costochondral junctions. Both children had normal growth, with their height and body weight greater than the 50th and 97th percentile for age. Roentgenograms of their extremities showed the typical changes of vitamin D refractory rickets. Serum alkaline phosphatase levels were elevated and serum levels of calcium and phosphate were both within the normal range. No primary cause for the rickets, including nutritional deficiencies, was found in the two patients. Characteristic findings were persistently low serum 25-hydroxyvitamin D (25-OH-D) and normal 1,25-dihydroxyvitamin D (1,25-(OH)2-D). Improvements in clinical and X-ray findings were observed after either oral administration of 1 alpha-(OH)-D3 (9-15 micrograms per day) or massive vitamin D2 therapy (600,000 IU single injection). The low serum levels of 25-OH-D did not increase unless massive vitamin D2 therapy was also given. These two cases represent a unique form of rickets that does not meet the criteria for any type of previously known rickets.

25-Hydroxyvitamin D 2↗

HLA-DQB1 allele associates with idiopathic nephrotic syndrome in Japanese children.

HLA-DQA1 and -DQB1 genes were investigated in 30 Japanese children with idiopathic nephrotic syndrome (INS) using the polymerase chain reaction-restriction fragment length polymorphism method. Compared with control children, there was a significant increase in the HLA-DQA1*0501, DQB1*0301 and DQB1*0601 alleles, whereas the frequency of DQB1*0501 showed a significant decrease in the patients. The increase of DQA1*0501 can be explained as being a result of a linkage disequilibrium with DQB1*0301. The previous result demonstrating a positive association of DRw6 and DRw8 with INS is also assumed to be attributable to a linkage disequilibrium with DQB1*0301 and 0601. A total of 83% of patients compared with 37% of controls possessed DQB1*0301 and/or DQB1*0601 allele (P < 0.001, RR = 8.6). Only these alleles have alanine at residue 13 and tyrosine at residue 26 in the hypervariable region in the Beta 1 domain of DQB1 gene. These findings suggest that the unique amino acid residues in the DQB1 gene may contribute to disease susceptibility in Japanese children with INS.

Adolescent↗

Congenital hypothyroidism with delayed rise in serum TSH missed on newborn screening.

We report on a female patient with congenital hypothyroidism (CH) missed on a newborn screening test. She is now 10 years old with retarded development. The patient was born premature at 34 weeks of gestation with birth-weight of 1515 g, and was judged to be normal in the screening programme of Niigata Prefecture. However, she gradually suffered from poor weight gain and retarded development with stridor at breathing. Serum thyroid stimulating hormone (TSH) levels were rechecked and showed high values with normal T3 and T4 levels. She was referred to our hospital at the age of 13 months. She was diagnosed as having CH (ectopic thyroid) with a delayed rise in blood TSH concentration, probably due to the prematurity of the hypothalamic-pituitary-thyroid axis. L-thyroxine therapy brought a decline in TSH levels with partial improvement of her symptoms. Regardless of the result of newborn screening, infants with elevated serum TSH levels should be carefully examined for possible CH, even when T3, T4 and free T4 values are in the normal range.

Child↗

Screening for neuroblastoma: a 9-year birth cohort-based study in Niigata, Japan.

Between April 1985 and March 1994 (9 years), 229,346 babies were born in Niigata prefecture, and 201,888 (88.0%) underwent mass screening (MS) for neuroblastoma at 6 months of age. To date, 29 infants have been screen-detected as having neuroblastoma (1:7908). All screen-detected patients survived after removal of the primary tumor. In the same birth cohort, 17 additional children were clinically diagnosed as having neuroblastoma. The cumulative incidence rate of neuroblastoma at 5 years of age was 10.5 per 100,000 live births in the 5-year birth cohort before MS was introduced, and 18.6 per 100,000 in the first 5-year birth cohort after MS was introduced. These values were not statistically different. The birth cohort incidence rate increased significantly to 22.2 per 100,000 (p < 5% compared with before MS) after the method of MS was changed to high-power liquid chromatography (HPLC), even though this latest birth cohort has not been followed for 5 years. The population-based mortality rate from neuroblastoma was 5.9 per 100,000 in the 5-year birth cohort before MS, and 4.5 per 100,000 after MS in the first 5-year birth cohort, using the vanillymandelic acid (VMA) spot test. These values were not statistically significant. In contrast, no death was observed in the next 4-year birth cohort after MS using HPLC; however, this birth cohort has not yet been followed for 5 years.

Chi-Square Distribution↗

Persistent non-familial asymptomatic hyperphosphatasemia: a report on three cases.

Three male children, aged 9 days, 2 years and 13 years, were found to have elevated serum alkaline phosphatase (ALP) activity (hyperphosphatasemia) in the absence of disease. In these three cases, elevation of ALP activity had persisted for 6-10 years. These patients did not inherit the disease from their parents. Isoenzyme determination revealed a skeletal origin of the elevated ALP in the three patients. They were diagnosed as having persistent non-familial asymptomatic hyperphosphatasemia (PNAH) which differs from transient and persistent asymptomatic familial hyperphosphatasemia. Reviewing the literature, although the term PNAH had not been used, two similar cases have been reported in a 24-year-old female and in a 27-year-old female. PNAH may be another type of benign hyperphosphatasemia.

Adolescent↗

Incidental Lewy body disease in a patient with REM sleep behavior disorder.

We studied an 84-year-old man with a 20-year history of nocturnal violent behavior during sleep, but no other clinically evident neuropsychiatric disorders. Polysomnographic investigations confirmed that he suffered from REM sleep behavior disorder (RBD). Histopathologic examination revealed he had Lewy body disease with a marked decrease of pigmented neurons in the locus ceruleus and substantia nigra. These histologic findings represent the first documented evidence of a loss of brainstem monoaminergic neurons in clinically idiopathic RBD and suggest that Lewy body disease might provide an explanation for idiopathic RBD in the aged.

Aged↗

Studies on dissolution tests for soft gelatin capsules by the rotating dialysis cell (RDC) method. VI. Preparation and evaluation of ibuprofen soft gelatin capsule.

We prepared soft gelatin capsules (SC) containing ibuprofen (IB), a widely used phenylpropionic acid-derived antiphlogistic-analgesic drug. To evaluate the SC, in vitro dissolution tests were performed both by the paddle (PD) method described in the Japanese Pharmacopoeia (JPXII) and by the rotating dialysis cell (RDC) method which we previously developed and evaluated for application. In vivo, the blood IB concentration was determined after administration to beagles. Higher bioavailability was observed after administration of the SC containing IB than after administration of the bulk IB powder. A higher correlation was observed between the in vitro dissolution behavior and in vivo results by the RDC method than by the PD method, suggesting the usefulness of the RDC method in the dissolution test of SC.

Animals↗

Nitric oxide-mediated neurogenic relaxation in monkey mesenteric veins.

The purpose of this investigation was to determine if neurally induced vasodilatation is mediated by nitric oxide (NO) in monkey mesenteric veins. Helical strips of the monkey mesenteric vein were exposed to the bathing media for isometric tension recording, and perivascular nerves were stimulated by nicotine. Nicotine produced a contraction, which was potentiated by treatment with NG-nitro-L-arginine, a NO synthase inhibitor, the effect being reversed by L-arginine. The nicotine-induced contraction was reversed to a relaxation by prazosin. The relaxation was abolished by the NO synthase inhibitor, and it was restored by L-arginine. D-Enantiomers were without effect. The response was not influenced by timolol and indomethacin, but was abolished by hexamethonium and oxyhemoglobin. There were perivascular nerve fibers containing NO synthase immunoreactivity in the monkey vein. Neurally induced venous relaxations appear to be mediated by NO from perivascular nerves, as seen in dog and monkey mesenteric arteries. It is concluded that monkey mesenteric veins are innervated by nitroxidergic and adrenergic nerves, which may balance the vascular tone.

Animals↗

[Intestinal motility after massive small bowel resection].

To evaluate intestinal motility after 80% massive distal small bowel resection (MSBR), we continuously monitored interdigestive and postprandial bowel motility using bipolar electrodes and/or contractile strain gage force transducers in conscious beagle dogs before, and at 0-4 weeks and 8-13 months after the surgery. Fasting duodenal migrating myoelectric (or motor) complexes (MMCs) occurred at longer intervals in the short-term after 80% MSBR than in controls, and were simulated in long-term that in controls. MMCs arising from the duodenum were often migrated to the proximal jejunum, the jejunum above the anastomosis, and to the terminal ileum beyond the anastomosis. The velocity of duodenal MMC propagation was slowed in every intestinal segment in the short-term, and had not recovered even long after the operation. The duration of the postprandial period without duodenal MMCs was prolonged significantly in the short-term, and still remained longer in the long-term than in controls. These findings suggest that changes in gut motility after MSBR tend to compensate for the shorter intestine and maintain small bowel absorption early postoperatively, and adaptations of motility would occur over the long-term to increased intestinal absorption.

Animals↗

[Congenital metabolic disorder].

In children, tubulo-interstitial nephritis (TIN) is often associated with obstructive uropathy, metabolic disorders or hereditary diseases. The author reviewed congenital metabolic disorders (Fanconi syndrome, cystinosis, Lowe's syndrome, and hyperoxaluria) as causes of TIN. The Fanconi syndrome is caused by numerous disorders including cystinosis and Lowe's syndrome, and refers to a dysfunction of the proximal tubule leading to excessive urinary excretion of amino acids, glucose, phosphate, bicarbonate, etc. Prognosis of idiopathic Fanconi syndrome is not so bad if electrofluid balance is well maintained. On the other hand, prognosis of the infantile type of cystinosis, Lowe's syndrome, or hyperoxaluria "type 1" is poor. The pathophysiology of each disease should be fully understood for early diagnosis and treatment.

Child↗