PubMed Health⌕ Search

Biomedical subjects

Yasuhiro Komatsu

Publications and source records attributed to Yasuhiro Komatsu.

9 recordsLinked to original sources

Delayed adrenal insufficiency long after unilateral adrenalectomy: prolonged glucocorticoid therapy reduced reserved secretory capacity of cortisol.

A 51-year-old woman with Cushing's syndrome underwent unilateral adrenalectomy for left adrenal adenoma. After 7 years of prednisolone treatment (with some interruptions), followed by 4 years of total withdrawal from prednisolone treatment, she presented with hypotension, weight loss, general fatigue, nausea, hyponatremia and hypoglycemia. These clinical features together with a low response in the rapid adrenocorticotropic hormone test led to the diagnosis of acute adrenal insufficiency. Relatively low serum adrenocorticotropic hormone levels in the face of increased demand for cortisol during adrenal crisis suggested a disordered hypothalamic-pituitary function, indicating secondary adrenal insufficiency. This patient demonstrated the etiology of acute adrenal insufficiency long after unilateral adrenalectomy in association with subsequent glucocorticoid therapy. A reduction in the reserved secretory capacity of cortisol after prolonged prednisolone treatment was considered to have induced secondary adrenal insufficiency, even after 4 years of total withdrawal from prednisolone.

Acute Disease↗

Effects of Dai-saiko-to (Da-Chai-Hu-Tang) on plasma lipids and atherosclerotic lesions in female heterozygous heritable Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits.

We investigated the antihypercholesterolemic effects of traditional Japanese herbal medicine Dai-saiko-to (Da-Chai-Hu-Tang in Chinese) in female heritable Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits. The plasma total cholesterol levels increased for up to 12 weeks after beginning a diet containing 0.1% cholesterol then reached a plateau of about 603 mg dl(-1). Dai-saiko-to was administered at doses of 0.5-1.0 g kg(-1) per day or pravastatin 10 mg kg(-1) per day for 24 weeks. Plasma total cholesterol levels were significantly decreased in the groups administered Dai-saiko-to 1.0 g kg(-1) per day or pravastatin for 4-24 weeks, whereas there were no change with plasma phospholipid and triglyceride levels. However, Dai-saiko-to 1.0 g kg(-1) per day significantly decreased plasma LDL cholesterol levels, but had no effect on either VLDL- or HDL-cholesterol levels. Moreover, LDL-receptor mRNA levels in the liver were significantly increased in the Dai-saiko-to 1.0 g kg(-1) per day group compared with those of animals receiving the 0.1% cholesterol diet. In addition, both groups receiving Dai-saiko-to 1.0 g kg(-1) per day and pravastatin showed a significantly reduced percentage of intimal surface area of thoracic aorta involved with atheromatous plaques in the thoracic aorta at 24 weeks. These results indicated that Dai-saiko-to 1.0 g kg(-1) per day significantly decreased the plasma cholesterol levels and atheromatous plaque area due to expression of the LDL mRNA gene in the liver.

Animals↗

Effect of a traditional Chinese herbal medicine, Ren-Shen-Yang-Rong-Tang (Japanese name: Ninjin-Youei-To), on oligodendrocyte precursor cells from aged-rat brain.

Understanding of oligodendrocyte precursor cells and their role in the generation of oligodendrocytes in developing and adult rodents has been considered, particularly much less is known about aged-rodent oligodendrocyte precursor cells and their cell lineage. In this present study, we have developed oligodendrocyte cultures from the 30-month-old rat brain and examined whether oligodendrocyte precursor cells can proliferate in vitro. Adult oligodendrocyte precursor cells (O1(-), O4(+)) and oligodendrocytes (O1(+), O4(+)) are present in the cultures of the 30-month-old rat brain. They are also capable of proliferating and differentiating in the cultures. These capabilities increased four- to fivefold, when the aged rats are treated with Ninjin-Youei-To for 3 months in comparison with those of control aged rats. These results suggest that Ninjin-Youei-To has a potential mitotic effect on oligodendrocyte precursor cells in aged-rat brains and may be expected to have a therapeutic effect on brain aging.

Aging↗

Changes of materials that scavenge 1,1-diphenyl-2-picrylhydrazyl radicals in plasma by per-oral administration of Kampo medicine, Ninjin-yoei-to in rats.

The Kampo medicine, Ninjin-yoei-to, scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals in a dose-dependent fashion as did ascorbic acid and alpha-tocopherol. Ninjin-yoei-to, which is composed of 12 herbs, had a potent DPPH radical scavenging ability. We investigated the transition of the materials that scavenge DPPH radicals in plasma after oral administration of Ninjin-yoei-to to rats. When 1.0 g kg(-1) Ninjin-yoei-to was administered, the DPPH radical scavenging ability increased at 30 min and biphasic peaks were observed at 2 h and at 10 h. From the response-time profile, kinetic parameters including values for K(a) (absorption rate constant), t(max) (peak concentration time), t(1/2) (half-life) and MRT (mean residence time) of the radical scavenging ability in plasma could be calculated for DPPH radicals. K(a) values were 0.53 +/- 0.03 and 0.36 +/- 0.07 h, t(max) values were 2.1 +/- 1.04 and 8.56 +/- 2.69 h, t(1/2) values were 1.60 +/- 0.12 and 3.39 +/- 1.72 h, and MRT values were 4.14 +/- 1.59 and 8.18 +/- 2.55 h, respectively. These parameters calculated from the antioxidation dynamics were considered to offer a very meaningful procedure for examining the effects of Ninjin-yoei-to.

Animals↗

Urinary acidification in extremely low birth weight infants.

Premature infants often present metabolic acidosis without protein load in the early neonatal period, around days 4-6. In order to elucidate the cause of acidosis, we investigated urinary acidification of infants in the early neonatal period. Urine pH, fractional excretion of HCO(3)(-) (FEHCO(3)), excretion of HCO(3)(-) and NH(4)(+) of the appropriate-for-date infants were measured on days 0-2 and on days 4-6 of life. Extremely low birth weight (ELBW) infants showed higher urine pH than more than 1500 g birth weight infants. FEHCO(3) and HCO(3)(-) excretion were of high values in ELBW infants on days 0-2, but decreased on days 4-6. Urine NH(4)(+) excretion rate was lower in ELBW infants than in birth weight more than 1000 g on days 0-2 of life and still remained at a low rate on days 4-6. These data indicated that insufficiency of NH(4)(+) excretion is the main cause for metabolic acidosis of ELBW infants in the early neonatal period.

Acidosis↗

Age-dependent phosphate homeostasis is regulated by a circulating factor.

To evaluate the age-dependent phosphate homeostasis, we studied the serum inorganic phosphate (P(i)) concentration in 78 recipients, aged 5-25 years, a year after renal transplantation (RT). The significant age-dependent decline of the serum P(i) concentration was observed in recipients (p < 0.0001) as well as in normal children. Our study revealed that a circulating factor may play a central role in the age-dependent change of phosphate regulation in human.

Adolescent↗