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Biomedical subjects

Fumitaka Ohsuzu

Publications and source records attributed to Fumitaka Ohsuzu.

80 records · Page 5Linked to original sources

Assessment of diabetic autonomic neuropathy using twenty-four-hour spectral analysis of heart rate variability: a comparison with the findings of the Ewing battery.

A power spectral analysis of heart rate variability has been applied in order to assess diabetic autonomic neuropathy and high frequency spectra are thus considered to possibly reflect vagal nerve integrity in patients with diabetes mellitus. The purpose of this study was to investigate the relationship between the findings of high frequency spectra analysis and the results of the Ewing battery. We performed 24-hour power spectral analysis using an ambulatory ECG monitoring system and standard tests in order to assess diabetic autonomic neuropathy (Ewing battery) in 18 diabetic patients to compare their diagnostic values for diabetic autonomic neuropathy. We used the high frequency amplitude (high frequency spectra; 0.15-0.40 Hz) as a direct measure of vagal nerve integrity from each hourly spectral plot. All hourly high frequency spectra decreased along with the impaired assessment of the battery, especially during the night when the high frequency spectra showed a manifest increase in patients classified as normal according to the battery. High frequency spectra during the night while asleep (22:00-05:00) and during a 24-hour period significantly correlated with the results of the battery. These values markedly decreased even in patients classified as having early vagal damage when compared with those classified as normal. High frequency spectra during night closely reflected the intrinsic vagal nerve integrity in patients with diabetes mellitus. High frequency spectra during night or a 24-hour period is a simple and sensitive measure of diabetic autonomic neuropathy and is considered to be a useful modality for detecting even early changes in autonomic dysfunction.

Adult↗

Complex regional pain syndrome type I induced by pacemaker implantation, with a good response to steroids and neurotropin.

An 84-year-old woman was referred to our hospital because of aches and pain in her left hand and foot. Three months before her symptoms occurred, a pacemaker had been implanted for the treatment of a 2:1 atrioventricular block with bradycardia. In an X-ray examination, prominently decreased bone density was noted in her left fingers and toes. She was diagnosed to have CRPS-I, which was considered to have been induced by the pacemaker implantation. After treatment with methylprednisolone and Neurotropin, her symptoms dramatically improved.

Aged↗

Polyarteritis associated with hypopharyngeal carcinoma.

A rare case of polyarteritis associated with a solid tumor is presented. A 66-year-old man was referred to our hospital, because of gangrene in the bilateral fingers and toes, right pleural effusion, and an abnormal sensation in the throat. A diagnosis of polyarteritis was made based on pleuritis, digital gangrene and the arteriography findings. He also had a hypopharyngeal carcinoma. After being treated with intermittent intravenous cyclophosphamide, oral corticosteroid, alprostadil and aspirin, the pleural effusion rapidly disappeared, while the digital gangrene gradually improved. For the treatment of hypopharyngeal carcinoma, radiation therapy was initiated and resulted in complete disappearance.

Aged↗

Cardiac autonomic nervous dysfunction in diabetic patients with a mitochondrial DNA mutation: assessment by heart rate variability.

OBJECTIVE: To elucidate the degree and characteristics of cardiac autonomic nervous dysfunction in diabetic patients associated with a mitochondrial DNA mutation at base pair 3243. RESEARCH DESIGN AND METHODS: We investigated heart rate variability using 24-h Holter monitoring in 10 diabetic patients with the mutation compared with 55 ordinary diabetic patients and 45 nondiabetic control subjects. RESULTS: Age and sex were similar in the three groups. Between patients with the mutation and ordinary diabetic patients, the duration of diabetes and blood glycemic levels were not different. In the time domain analysis of heart rate variability, patients with the mutation and ordinary diabetic patients had significantly smaller SDNN index and pNN50 than control subjects. Compared with ordinary diabetic patients, patients with the mutation had smaller SDNN index (P < 0.02), but rMSSD and pNN50 were not different. In the frequency domain analysis, total, low frequency (LF), and high frequency (HF) spectra were significantly smaller in patients with the mutation and ordinary diabetic patients than in control subjects. Compared with ordinary diabetic patients, patients with the mutation had smaller total and LF spectra (P < 0.02). However, HF spectra were not significantly different. Notably, the LF/HF spectra ratio was lower in patients with the mutation than in ordinary diabetic patients and control subjects (P < 0.05), but this ratio was similar in ordinary diabetic patients and control subjects. CONCLUSIONS: Our results suggest that diabetic patients with the mitochondrial DNA mutation have more severely impaired cardiac autonomic nervous function with sympathovagal imbalance, as compared with ordinary diabetic patients.

Age of Onset↗

Sweet elements of Siraitia grosvenori inhibit oxidative modification of low-density lipoprotein.

This study examined the ability of sweet elements extracted from Siraitia grosvenori (SG) to inhibit the oxidation of LDL. We monitored the formation of conjugated diene during copper-mediated LDL oxidation in the presence or absence of sweet elements of whole extract of SG (SG extract) or cucurbitane glycosides (CGs) purified from SG extract as sweet elements. CGs consist of Mogroside IV (Mog.IV), Mogroside V (Mog.V), 11-Oxo-mogroside V (11-Oxo-mog.V), and Siamenoside I (Sia.I). In addition, the effect of these elements on human umbilical vein endothelial cell (HUVEC)- mediated LDL oxidation was tested by measuring production of lipid peroxides. SG extract inhibited copper-mediated LDL oxidation in a dose-dependent fashion, but neither glucose nor erythritol suppressed the oxidation. Among CGs, 11-Oxo-mog.V significantly inhibited LDL oxidation, and prolongation of the lag time during LDL oxidation by 11-Oxo-mog.V was dose-dependent. The lag time (119.7 +/- 8.9 min) in the presence of 200 microM 11-Oxo-mog.V was significantly longer than that (76.8 +/- 5.5 min) of control (p < 0.01). In addition, SG extract and 11-Oxo-mog.V inhibited HUVEC-mediated LDL oxidation in a dose-dependent manner. These results demonstrate that SG extract can inhibit LDL oxidation and that 11-Oxo-mog.V, a sweet element of SG extract, provides the anti-oxidative property of SG which might reduce the atherogenic potential of LDL.

Cells, Cultured↗

[The mechanism of neurally mediated syncope assessed by an ambulatory radionuclide monitoring system and heart rate variability indices during head-up tilt].

PURPOSE: Previously, we tested the hypothesis that the great decline in left ventricular volume during head-up tilt test could trigger ventricular mechano-receptor activation, using ambulatory radionuclide monitoring system (C-VEST system). The aim of this study is to investigate the mechanism of tilt-induced syncope further, based on our previous report. METHOD: We measured the temporal changes in left ventricular volume, ejection fraction, cardiac output, and heart rate variability indices during head-up tilt test in 34 patients with syncope of an underdetermined etiology. RESULT: Twenty-two patients had a positive response (P group). Twelve patients showed a negative response (N group). Before syncope, left ventricular volume declined (P group, diastolic volume; -7.9 +/- 6.8%: systolic volume; -23.3 +/- 33.8%: N group, diastolic volume; -2.5 +/- 1.9%: systolic volume; 0.6 +/- 9.5%: p < 0.05), ejection fraction increased (P group, 3.9 +/- 2.5%; N group, -3.5 +/- 7.2%; p < 0.005), and high frequency spectra increased (P group, 12.0 +/- 20.3%; N group, 3.1 +/- 9.7%; p < 0.05), more extremely in the P group than in the N group. The value of the high frequency spectra before the head-up tilt test was significantly higher in the P group than in the N group (P group, 5.8 +/- 0.9 ms; N group, 5.0 +/- 1.1 ms; p < 0.05). CONCLUSIONS: (1) The precise evaluation of left ventricular volume by ambulatory radionuclide monitoring system combined with a heart rate variability analysis is considered to be useful for clarifying the pathophysiology of neurally mediated syncope. (2) Patients with neurally mediated syncope have higher baseline parasympathetic tone than normal population.

Adult↗

Effect of chronic oral supplementation with vitamins on the endothelial function in chronic smokers.

Cigarette smoking has been associated with endothelial dysfunction including impaired endothelium-dependent flow-mediated dilation (FMD). In cigarette smokers, increased oxygen-derived free radicals have been suspected of being one of the major causes of endothelial dysfunction, owing possibly to the inactivation of nitric oxide by free radicals. Vitamins C and E are widely used antioxidant vitamins, which have also been reported to effectively improve the endothelial function in several conditions. To test the effect of moderate-term oral antioxidant vitamin supplementation on the endothelial function in smokers, the authors evaluated the combined effect of vitamins C and E, administered in normal dosages, on FMD in young male smokers. A prospective interventional study was performed. In 15 healthy male subjects (mean age, 24.4 +/-2.5 years old). They studied FMD in the brachial artery by using high-resolution ultrasound. The vascular effects of moderate-term oral supplementation with vitamin C (1.0 g/day) and vitamin E (500 mg/day) were determined during reactive hyperemia, which causes endothelium-dependent FMD. They performed a vascular function study 3 times including before vitamin supplement, after 25 days of vitamin supplement, and 4 weeks after the cessation of the vitamin supplement. The flow-mediated dilator response measurements were repeated twice a day before vitamin supplements, and the repeatability obtained from these measurements was found acceptable (variability of FMD <2%). The oral antioxidant vitamin supplement significantly restored FMD (3.8 +/-2.2% vs 5.9 +/-2.5%; p<0.05), however, this effect disappeared 4 weeks after the vitamin supplementations ended. The combined usual dosage of vitamins C and E supplements was found to improve the endothelial function in chronic smokers.

Administration, Oral↗

Provocation of microvessel spasm by low-dose acetylcholine in patients with suspected coronary artery disease--two case reports.

Endothelial dysfunction plays an important role in the pathogenesis of cardiac syndrome X, and intracoronary low-dose acetylcholine infusion is a widely used diagnostic modality for studying the coronary artery endothelial function. The authors herein report 2 cases of cardiac syndrome X with coronary artery endothelial dysfunction and microvessel spasm. The findings of non-invasive testing were positive for ischemia. Coronary angiograms appeared entirely normal in both cases. However, the intracoronary infusion of low-dose (1.5-15 microg/minute) acetylcholine demonstrated an impairment of the coronary blood flow response and consequently provoked an ST-segment elevation in an electrocardiogram. The coronary angiograms showed no spasm in the epicardial arteries. These patients are thus suggested to have cardiac syndrome X with microvessel spasms associated with coronary artery endothelial dysfunction.

Acetylcholine↗