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Biomedical subjects

M Uchiyama

Publications and source records attributed to M Uchiyama.

At least 253 records · Page 14Linked to original sources

Effects of a small dose of triazolam on P300 and resting EEG.

The aim of the present study was to clarify whether cognitive impairments caused by benzodiazepines (BDZs) are a consequence of their specific direct effects on cognitive function or whether they are explained as secondary effects of increased sleepiness. Ten healthy men (mean age, 33.9 years) participated in two experimental sessions in a randomized cross-over, double-blind study: in one session subjects were given a placebo and in the other they were given 0.125 mg triazolam (TRZ). Each experimental session was conducted on 1 day. After a pre-drug EEG recording and an event-related potential (ERP) recording, under an oddball paradigm, subjects took the TRZ or placebo orally at 1000 hours. Thereafter, EEG and ERP recording sessions, following the same procedure as the pre-drug sessions, were conducted at 1, 2, 4, 6 and 8 h after drug administration. The EEG and ERP recordings from Cz and Pz referred to the bilaterally linked ear electrodes were used. We found that P300 latency was significantly prolonged in TRZ condition at 2 h (Pz) and 4 h (Cz and Pz) after TRZ, and that the P300 amplitude was significantly reduced at 2 h (Cz and Pz) and 4 h (Pz) after TRZ, compared to the same times after placebo. The absolute power values for the theta (4-7 Hz), alpha 1 (8-9 Hz), and alpha 2 (10-12 Hz) bands did not differ at any measurement time between the treatments. Only the beta band (13-19 Hz) power value was significantly elevated after the TRZ administration (versus placebo). No significant sedative effects were detected in subjective measurements. These results indicate that a single oral dose of 0.125 mg TRZ caused cortical changes without distinct general sedation or subjective sleepiness.

Adult↗

Efficacy of mianserin on symptoms of delirium in the aged: an open trial study.

1. The authors administered the tetracyclic antidepressant mianserin to aged patients with delirium to examine its efficacy in delirium. 2. The subjects were 62 consecutive aged patients with delirium, diagnosed according to DSM-IV. 3. The patients' symptoms of delirium were assessed once a week over the 4-week study period using the Delirium Rating Scale. 4. It was found that mianserin was effective, especially in treating behavioral and sleep-wake disturbance and that it was almost free from undesirable side-effects. It appears to be particularly useful for elderly patients with delirium, who easily develop extrapyramidal side-effects when given antipsychotic drugs. These properties of mianserin are worthy of further study.

Aged↗

Mediastinal yolk sac tumor in a young girl: case report and review of the literature.

The authors report a rare case of a female infant who underwent successful treatment of a mediastinal yolk sac tumor. Therapy included four cycles of preoperative PVB (cisplatinum, vinblastine, bleomycin), complete surgical resection of the tumor, and one postoperative cycle of PVB and four cycles of VAC (vincristine, actinomycine, cyclophosphamide) chemotherapy. The successful treatment of this tumor depends on preoperative chemotherapy to reduce the size, followed by complete surgical excision with subsequent postoperative chemotherapy. Recent improvements in the treatment of mediastinal yolk sac tumors are discussed.

Antineoplastic Combined Chemotherapy Protocols↗

Main ginseng saponin metabolites formed by intestinal bacteria.

Ginseng saponin metabolites produced by human intestinal bacteria and the urinary and blood compounds after oral administration of Ginseng extract and its saponins in human and specific pathogen-free rats were examined in order to elucidate their metabolites absorbed from the intestines. The main metabolites of ginsenosides Rb1, Rb2, Rc, Re, and Rg1 after anaerobic incubation with fecal flora were identified as 20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol (I) 20-O-[alpha-L-arabinopyranosyl (1-->6)-beta-D-glucopyranosyl]-20(S)-protopanaxadiol (II), 20-O-[alpha-L- arabinofuranosyl(1-->6)-beta-D-glucopyranosyl]-20(S)-protopanaxadiol+ ++ (III), and 20(S)-protopanaxatriol (IV), though the metabolic rate and mode were affected by fermentation media. Furthermore, metabolites I-IV and 20(S)-protopanaxadiol (XII) were detected in blood (0.3-5.1 micrograms/ml) and in urine (2.2-96 micrograms/ day) after the oral administration of Ginseng extract (150 mg/ kg/day) to human and of total saponin (1 g/kg/day) to rats.

Animals↗

Enzyme-linked immunosorbent assay of pravastatin, a HMG-CoA reductase inhibitor, in human plasma.

An enzyme-linked immunosorbent assay (ELISA) was developed for sensitive and specific determination of pravastatin (PS) sodium, a HMG-CoA reductase inhibitor. Preparation of immunogens to obtain antisera was carried out using chemically modified PS; beta-alanine derivative of PS (for ELISA-1) and 5-deoxy- PS (for ELISA-2) were linked to bovine serum albumin via its terminal carboxylic acid by the N-succinimidyl ester method, to avoid intramolecular lactonization of PS. Enzyme-labeled antigens were prepared similarly by coupling with horseradish peroxidase, and were used by homogeneous combination of antisera. The enzymic activity was determined using a microtiter plate coated with second antibody and tetramethylbenzidine as a chromogenic substrate. Both of the ELISA systems enabled the determination of PS in a range of 5 to 500 pg/well, with an IC50 of 36 to 130 pg/well. Cross-reactivties with main metabolites in plasma, which differed from PS in decaline moiety, were less than a few percent. When ELISA-1 was applied to the determination of PS in human plasma directly after dilution with the ELISA buffer, the detection limit and the intra-assay coefficient (5 ng/ml of PS) were 500 pg/ml and 4.5%, respectively. Further, ELISA-1 was validated by gas chromatography-mass spectrometry with the determination of PS in human plasma after oral administration at a dose of 10 mg/body.

Administration, Oral↗

Delayed phase jumps of sleep onset in a patient with non-24-hour sleep-wake syndrome.

We studied a 30-year-old man with non-24-hour sleep-wake syndrome. To investigate the relationship between environmental light-dark cycles and his sleep-wake rhythm, we documented his sleep log and rectal temperature data without any therapeutic interventions. We found that 1) the patient's sleep-wake pattern consisted of two different components, appearing alternatively, with a period of 27.2 days: regular free-run (R free-run), consisting of a daily 30- to 60-minute regular delay of sleep onset; and jumping free-run (J free-run), with clusters of delayed (> 4 hours) phase jumps in sleep onset (DP jump): 2) the frequency of sleep onset was higher during late evening hours to midnight hours than in the daytime; 3) DP jumps occurred exclusively when the prior sleep onset was delayed into the daytime; and 4) a cluster of DP jumps was likely to start when the patient's low temperature zone (a period in which rectal temperature was below average) at subjective night was illuminated by sunlight. These results suggest that DP jumps in the patient may occur due to illumination of the delay portion of the phase-response curve.

Adult↗

Analysis of body-burden measurements of 137Cs and 40K in a Japanese group over a period of 5 years following the Chernobyl accident.

A selected group of about 20 male researchers at the NIRS that reside in Chiba, Japan, was measured for total body content of radiocesium and 40K every 3 mo from February 1986 to May 1991. A whole-body counter at the NIRS was used to measure their radioactivity in a scanning mode of 5 cm min-1 in a shielded iron room with walls 20 cm in thickness. A maximum radiocesium level of 59 Bq was observed in May 1987. The annual change in the body burden decreased with an apparent half-time of 1.8 y after May 1987. The period of five years was sufficient to eliminate the effects of the accident in this group. Even in the most contaminated period, the dose from radiocesium was below 2 microSv y-1. The cumulative dose for 5 y was estimated to be 5.6 microSv, which is nearly equal to the total dose to the Japanese people caused by the artificial radionuclide fallout for the first year following the accident. It is much smaller than the committed dose of 82 microSv for internally deposited 137Cs resulting from nuclear explosions in 1961 and 1962 and the annual dose of 170 microSv from internal 40K. No detectable health risk was expected for the present group.

Body Burden↗

Intestinal motility after massive small bowel resection in conscious canines: comparison of acute and chronic phases.

To evaluate intestinal function after 80% massive distal small bowel resection (MSBR), we continuously monitored interdigestive and postprandial bowel motility using bipolar electrodes and/or contractile strain gauge force transducers in conscious beagle dogs before and at 2-4 weeks (acute postoperative phase; acute phase) and 8-13 months (chronic postoperative phase; chronic phase) after the surgery. Fasting duodenal migrating myoelectric (or motor) complexes (MMC) occurred at longer intervals in the acute phase after 80% MSBR than in control beagles. Intervals between duodenal MMC in the chronic phase were similar to those found in control beagles. MMC arising from the duodenum were often interrupted before the jejunum above the anastomosis in the acute phase, and a slight recovery of propagation frequency to the jejunum above the anastomosis was observed in the chronic phase. However, duodenal MMC did not migrate smoothly to the terminal ileum in both groups. In the acute phase, the velocity of duodenal MMC propagation was slowed in every intestinal segment, including the duodenum and the jejunum above the anastomosis, and had not recovered even long after the operation. The duration of the postprandial period without duodenal MMC was prolonged significantly in the acute phase postoperatively. Although it shortened in the chronic phase, it still remained significantly longer 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. However, these compensatory changes decrease over the long term, and their adaptive contributions to increased intestinal absorption may decrease as well.

Anastomosis, Surgical↗

Differentiation induction therapy with all-trans retinoic acid (ATRA) in a patient with secondary 11q23 leukemia.

PURPOSE: Frequently recurrent leukemia is encountered in childhood and is usually resistant to multidrug therapy. We evaluated the efficacy of differentiation induction therapy in a child with leukemia. PATIENT AND METHODS: We administered all-trans retinoic acid (ATRA) alone, and then a combination of low-dose 1-beta-D-arabinofuranosylcytosine (Ara-C), to a 7-year-old boy who had leukemia secondary to etoposide with chromosomal abnormality 11q23. RESULTS: The patient exhibited a good response to ATRA and had a complete remission after combination therapy of ATRA and low-dose Ara-C. CONCLUSION: Differentiation induction therapy with ATRA was effective in treating a patient with recurrence of leukemia without t(15;17) translocation, and which is resistant to conventional cytotoxic treatment.

Antineoplastic Combined Chemotherapy Protocols↗

Analysis of Met235 to Thr variant of the angiotensinogen gene in relation to the blood pressure and family history of essential hypertension in Japanese children.

A recent study reported a significant relationship between a T704-->C (Met235-->Thr) variant in exon 2 of the angiotensinogen gene in adults and essential hypertension. In the present study, this variant was detected in 131 Japanese children using a polymerase chain reaction. The allele frequency of the variant was 0.76. The genotype frequency of the homozygote for the allele was 0.59, and children who were homozygous had higher systolic blood pressure than those with the other two genotypes. No relationship was found between children's polymorphism and a family history of essential hypertension. These findings suggest that this molecular variant of the angiotensinogen gene may play some role in the regulation of blood pressure in Japanese children.

Angiotensinogen↗

Effect of clonidine on the height of a child with glycogen storage disease type VI: a 13 year follow-up study.

A 9-month-old male was found to have hepatomegaly when he was treated by his doctor for bronchitis. At the age of 2 years and 3 months, glycogen storage disease (GSD) of type VI (GSD VI) was diagnosed in this patient. Despite the recommended diet therapy, his growth was not good, changing under or along the line of -2.0 SD. At the age of 6 years, oral clonidine therapy (0.15 mg/day, 0.2 mg/m2 body surface per day) was started. Six to 10 months after the initiation of clonidine therapy, his height began to increase more than the values for -2.0 SD and once reached the value for -1.0 SD at the age of 10 years. His growth rate and bone age increased. Clonidine therapy was continued regularly for 7 years until the age of 13 years, 11 months. At that time his development was normal and his height reached 150.8 cm (-1.34 SD). However, cessation of the treatment at the patient's free will resulted in a reduction of the growth rate at age 15 years 6 months. These observations suggest the effect of clonidine therapy on height. Side effects were not noted during the clonidine therapy. Other clinical and laboratory findings of GSD VI also completely improved during treatment. In conclusion, administration of clonidine could be another treatment modality in children with GSD, not only of type VI but also I and III.

Administration, Oral↗

The usefulness of measuring body fat deposition for detecting obesity and atherogenesity in Japanese school children.

Body fat deposition was measured in overweight and non-overweight children using a bioelectrical impedance method, and its relationship with serum lipids and apolipoproteins was investigated in 90 overweight children (over 120% of their ideal weight) and 241 non-overweight children aged 10-15 years in Niigata Prefecture. The results were as follows. Overweight boys had significantly higher levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), atherogenic index (AI), RLP-cholesterol (RLP-C), apoA1, apoA2, apoB, apoC2, apoC3, apoE and the ratio of apoB to apoA1 than non-overweight boys. Overweight girls had significantly higher levels of TC, LDL-C, AI, remnant-like lopoprotein cholesterol (RLP-C), apoA2, apoB, apoC2, apoC3, apoE and the ratio of apoB to apoA1 than non-overweight girls. It has been reported that of all children studied 2.1% had higher levels of RLP-C than its upper limit known for adults (12 mg/dL). Of the overweight children in the present study, 4.4% had a high level of RLP-C whereas only 1.2% of non-overweight children had a high RLP-C level. No difference in the lipoprotein levels was found between overweight and non-overweight children. In both boys and girls, relative weight, body fat, skinfold thickness and body mass index (BMI) were correlated with the lipoprotein levels. Non-overweight boys whose body fat was over 20% had significantly higher levels of TC, LDL-C, apoA2, apoB, apoC2, apoE and apoB/A1 than those whose body fat was less than 20%. It was concluded that the measurement of body fat deposition, together with relative weight, was useful for detecting obesity and atherogenesity in Japanese school children.

Adolescent↗

Seasonal variation of mood and behaviour in a healthy middle-aged population in Japan.

A population survey of seasonality in six representative cities in Japan was conducted using the Japanese version of the Seasonal Pattern Assessment Questionnaire (SPAQ). The questionnaires were given to 951 parents (male: female ratio 1:1 age range 34-59 years) of high-school students. Significant regional differences in seasonal variations of mood, length of sleep, and weight were observed; the proportion of individuals reporting high seasonality in the two northern cities was significantly higher than that in the other areas. These results provide evidence for a northern predominance in the prevalence of seasonal affective disorder in Japan.

Adult↗

The relationship between the intrauterine environment and blood pressure in 3-year-old Japanese children.

In 195 Japanese children the systolic pressure at 3 years of age was inversely correlated to the body weight at birth and positively correlated to the mothers' systolic pressure during pregnancy: the average systolic pressure in children whose body weight at birth exceeded 3510 g was 3.0 mmHg, which was lower than that of children whose body weight at birth was 2990 g or less. There was an increase of 0.12 mmHg in the children's systolic pressure with each increment of 1 mmHg in the systolic pressure of their mothers. The systolic pressure at 3 years in children of mothers who had had pretibial oedema during pregnancy (101.0 +/- 8.8 mmHg) was significantly higher compared with children whose mothers did not have oedema (96.6 +/- 9.6 mmHg).

Anthropometry↗

Canine retinal arterial and arteriolar dilatation induced by nipradilol, a possible glaucoma therapeutic.

The effects of nipradilol, an ocular hypotensive drug, on isolated canine retinal central arteries and on retinal arterioles in vivo were investigated. Nipradilol (10(-9) to 10(-5) mol/l) produced a dose-related relaxation of the arterial strips contracted with prostaglandin F2 alpha which was not influenced by timolol or indometacin. The median effective concentration of this drug was five times that of glycerol trinitrate (GTN). The nipradilol-induced relaxation in the endothelium-intact strips was not influenced by NG-nitro-L-arginine, a nitric oxide synthase inhibitor, but was abolished by oxyhemoglobin and methylene blue. Treatment with high concentrations of sodium nitroprusside abolished the response to nipradilol, as observed with that to GTN. Retinal arterial strips responded to isoproterenol with a slight relaxation which was depressed by nipradilol. In anesthetized dogs, intra-arterial injections of nipradilol dilated the retinal arterioles in the ocular fundus; the dilator potency was approximately one fifth that of GTN. It is concluded that nipradilol dilates canine retinal arteries in vitro and arterioles in vivo, possibly due to activation of soluble guanylate cyclase and increased production of cyclic guanosine monophosphate that are associated with nitric oxide liberated from the molecule itself in the tissue but not derived from the endothelium and perivascular nerve. Beta adrenoceptor blocking action was determined in the retinal artery.

Animals↗

Study on proteinase-inhibiting capacity of plasma alpha 2-macroglobulin in idiopathic nephrotic syndrome.

We studied the relationship between plasma alpha 2-macroglobulin (alpha 2M) and depressed cell-mediated immunity in idiopathic nephrotic syndrome (INS). Plasma alpha 2M concentrations (mumol/l) were increased during relapses of INS; however, the proteinase inhibitory activity, measured using bacterial thermolysin, was significantly decreased when calculated per 1 mol of alpha 2M, implying a reduced proteinase-inhibiting capacity of alpha 2M. The decreased proteinase-inhibiting capacity of alpha 2M was associated with the inhibitory activity of plasma on normal lymphocyte blastogenesis. Purified alpha 2M, when complexed with chymotrypsin, intensively inhibited normal lymphocyte blastogenesis induced by concanavalin A, as compared with the free form of alpha 2M. From these results it is suggested that, although the amount of alpha 2M protein has increased in the plasma of INS patients during relapse, its binding capacity to proteinases has relatively decreased. The results of this study may provide speculation for both the well-known high plasma alpha 2M concentrations and the immunodepression, both of which have been observed in INS patients in the past few decades.

Adolescent↗

[Changes in intestinal motility after massive small bowel resection with a reversed jejunal segment].

To evaluate the functioning and effectiveness of a 20-cm reversed jejunal segment after 75-80% massive small bowel resection (MSBR), and whether migrating polarity changes or not, we continuously measured the postoperative bowel motility (using bipolar electrodes and/or contractile strain gage force transducers) in interdigestive and postprandial conscious dogs in short- (2-5 weeks) and long-term (6-10 months) after surgery. The fasting migrating myoelectric (or motor) complex (MMC) arising from the duodenum was often interrupted at the jejunum above the proximal anastomosis and did not migrate smoothly to the reversed segment or terminal ileum. In addition, brief small discordant contractions were frequent in the jejunum above the proximal anastomosis and the proximal part of the reversed segment. The duodenal MMCs predominantly propagated to the ileum through the inherent anatomic continuity of the bowel. These findings of the MMC propagation pattern are very similar in short- and in long-term after surgery. The duration of the postprandial period without duodenal MMC activity was markedly longer in short-term, but shorter in long-term (both were significantly longer than in controls). Marked dilatation of the jejunum and reversed jejunal segment was noted across the proximal anastomosis. These results suggest that the transit time and passage of intestinal contents can be delayed and stagnated for at least 10 months after MSBR with a 20-cm reversed jejunal segment. Although, reports on the polarity of peristalsis in the reversed segment in long-term followup have been contradictory in both experimental and clinical studies, this results support the conclusion that the reversed jejunal segment maintains its inherent propagative polarity and pattern over a long postoperative period.

Anastomosis, Surgical↗