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Biomedical subjects

Kazuo Chihara

Publications and source records attributed to Kazuo Chihara.

96 records · Page 6Linked to original sources
PubMed2002

Effect of low-dose of recombinant human growth hormone on bone metabolism in elderly women with osteoporosis.

BACKGROUND: There has been increasing evidence that the growth hormone (GH)-IGF-I axis plays an important part in the maintenance of bone mass. However, controversy still exists as to the effect of GH treatment on bone mineral density (BMD) in elderly patients with osteoporosis. OBJECTIVE: To investigate the effect of low-dose GH treatment on markers of body composition and bone turnover, serum concentrations of IGF-I and IGF-binding proteins (IGFBPs), and BMD at the radius and lumbar spine in eight elderly Japanese women with osteoporosis. METHODS: Participants were treated with GH as a single daily subcutaneous injection (0.125 IU/kg per week; 0.00595 mg/kg per day) for 48 weeks. RESULTS: Markers of bone formation and bone resorption were both increased up to 24 weeks of GH treatment. The bone formation markers remained increased during GH treatment, whereas the bone resorption markers returned to baseline values after 24 weeks of GH treatment. GH treatment caused a rapid (within 2 weeks) and sustained increase in serum IGF-I concentration. As for IGFBPs, serum concentrations of IGFBPs-2, -3 and -4 did not change significantly during GH treatment. In contrast, GH treatment caused a gradual increase in serum IGFBP-5 concentration, with a significant increase seen 48 weeks after the start of GH treatment. Radial BMD seemed to be increased during the late period of GH treatment, although the change was not significant. Lumbar BMD did not change during GH treatment. GH treatment caused a significant increase in hand grip strength. None of the GH-treated participants had new fractures and side effects such as edema and joint pain. Radial BMD was significantly increased after discontinuation of GH treatment for another 48 weeks and a similar tendency was observed at the lumbar spine (7.1+/-2.3% above pretreatment values for the radius and 3.6+/-2.0% for the lumbar spine). CONCLUSIONS: Low-dose GH treatment attenuated the decrease in muscle strength and bone mass in elderly women without side effects, although changes in nutrition and exercise might affect BMD. The present findings provide useful information regarding the use of low-dose GH treatment in elderly women with osteoporosis.

Aged↗
PubMed2002

[McArdle's disease with insulin resistance caused by obesity].

We reported a 29-year-old woman with McArdle's disease accompanied with insulin resistance. The patient was referred to our hospital because of muscle tenderness, swelling and weakness of lower extremities, and elevated serum CK level. Ischemic forearm exercise test showed no elevation in serum lactate and pyruvate levels. Muscle biopsy revealed significant reduction in phosphorylase activity both histochemically and biochemically. Pre-administration of glucagon had no effect on serum lactate and pyruvate levels after ischemic forearm exercise test while serum glucose elevated. The glucose clamp test confirmed insulin resistance. There was no reduction in number of insulin receptor or activity of tyrosine kinase. Her bodyweight was 78.4 kg and body mass index (BMI) was high as 32.0. Her obesity might be a causative factor of insulin resistance.

Adult↗
PubMed2001

Ghrelin modulates the downstream molecules of insulin signaling in hepatoma cells.

Ghrelin was identified in the stomach as an endogenous ligand specific for the growth hormone secretagogue receptor (GHS-R). GHS-R is found in various tissues, but its function is unknown. Here we show that GHS-R is found in hepatoma cells. Exposure of these cells to ghrelin caused up-regulation of several insulin-induced activities including tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1), association of the adapter molecule growth factor receptor-bound protein 2 with IRS-1, mitogen-activated protein kinase activity, and cell proliferation. Unlike insulin, ghrelin inhibited Akt kinase activity as well as up-regulated gluconeogenesis. These findings raise the possibility that ghrelin modulates insulin activities in humans.

Animals↗
PubMedDate not supplied

Risk factors for hip fracture in hemodialysis patients.

BACKGROUND: The incidence and mortality of hip fractures were several times greater in the patients with hemodialysis (HD) than in the general population. Although patients with end-stage renal disease develop renal osteodystrophy, few published data examined the risk factor of hip fractures in the dialysis population. METHODS: The present study was performed to compare various indices and bone mineral density (BMD) of HD patients with or without the history of hip fractures. Moreover, we analyzed the factors which predicted hip fractures in 183 patients with chronic HD enrolled in the cross-sectional study. RESULTS: Serum level of alkaline phosphatase was significantly higher in HD patients with hip fractures, compared to those without hip fractures. Oral calcium carbonate dose was significantly lower in HD patients with hip fractures. 1/3 radius (R)-BMD and ultradistal (UD)R-BMD were significantly lower in HD patients with hip fractures. However, lumbar spine (LS)-BMD was comparable in HD patients with or without hip fractures. Although there was no significant differences of BMD between with and without hip fractures in diabetes mellitus, UDR-BMD of patients with hip fractures was significantly lower than that of patients without hip fractures in chronic glomerulonephritis. Radial BMD was lower in female patients with hip fractures, compared to without hip fractures, although there were no significant differences in male patients. In multiple logistic regression analysis, oral calcitriol dose and 1/3R-BMD were selected as a risk factor of hip fractures in HD patients. CONCLUSION: Radial BMD was lower in HD patients with hip fractures. However, its contribution is different, depending on gender and the original disease leading to HD. Radial BMD and oral calcitriol dose seemed to be important to predict the risk of hip fractures.

Administration, Oral↗
PubMedDate not supplied

[Comparison between MRI and 3D-SSP in olivopontocerebellar atrophy and cortical cerebellar atrophy].

We compared images of three-dimensional stereotactic surface projections (3D-SSP) of SPECT with MRI images in spinocerebellar degeneration patients (13 olivopontocerebellar atrophy (OPCA) and 7 cortical cerebellar atrophy (CCA)). We analyzed a brain blood flow pattern with an image of statistics by 123I-IMP SPECT. In OPCA patients, a blood flow reduction was more remarkable in 3D-SSP than a degree of cerebellar atrophy in MRI. In patients with CCA, the cerebellum showed little blood flow reduction in 3D-SSP despite of apparent atrophy in MRI. Simultaneous examination both MRI and 3D-SSP might be useful for differential diagnosis of spinocerebellar degenerations.

Cerebellar Cortex↗