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Yutaka Naito

Publications and source records attributed to Yutaka Naito.

6 recordsLinked to original sources

Clinical evaluation of plasma free phenytoin measurement and factors influencing its protein binding.

The relationship between free phenytoin concentrations and clinical responses, and the factors influencing protein binding of phenytoin were investigated. A total of 119 plasma samples from 70 patients treated orally with phenytoin were analysed. The mean free phenytoin concentration was significantly higher in the patients who received phenytoin monotherapy and were classified as having a complete response (1.25 +/- 1.09 microg/ml) than that in the partial response group (0.59 +/- 0.07 microg/ml), whereas the mean total concentrations were not significantly different between the two groups. Samples were divided into three groups based on the free fraction of phenytoin, i.e. low, <5%; medium, 5%-10%; high, > 10%. The mean age (55.3 +/- 10.9 years) was significantly higher in the high group than in the low (42.7 +/- 21.2 years) and medium (42.8 +/- 16.0 years) groups. The mean creatinine clearance (CLcr) (55.3 +/- 10.9 ml/min) and serum albumin concentration (3.30 +/- 1.25 g/dl) were significantly lower in the high group than the low (88.3 +/- 29.0 ml/min and 4.08 +/- 0.50 g/dl, respectively) and medium (95.0 +/- 32.8 ml/min and 3.95 +/- 0.92 g/dl, respectively) groups. These results suggest that the free phenytoin concentration, rather than the total concentration, is more useful for monitoring antiepileptic effects in patients receiving phenytoin monotherapy. It was also found that the free phenytoin fraction was significantly influenced by aging, CLcr and serum albumin levels.

Adolescent↗

[Successful treatment by tacrolimus in two patients with Osserman's grade III intractable myasthenia gravis and elderly IIb].

Tacrolimus, a potent immunosuppressive agent, has recently become available for the treatment of myasthenia gravis (MG). However, few reports have evaluated the usefulness of tacrolimus in the elderly and in intractable MG classified as Osserman's grade IIb or higher. In this study, we examined the effects of tacrolimus in two patients with postthymectomy Osserman's grade III and IIb MG. The effects of tacrolimus were evaluated using the modified quantitative MG score (QMG score) and anti-acetylcholine receptor antibody (AChRAb) titer. Patient 1 was a 39-year-old woman with Osserman grade III MG. Her MG score improved after tacrolimus administration (3 mg/day), allowing gradual decreases in the doses of prednisolone and pyridostigmine because of improvement in MG symptoms. The AChRAb titer also decreased from 100.0 to 25.7 nmol/l during tacrolimus treatment. The concentrations of tacrolimus in whole blood ranged from 5.5 to 8.2 ng/ml during treatment. Patient 2 was a 68-year-old man diagnosed with Osserman grade IIb MG. After the initiation of tacrolimus treatment, dysphagia improved dramatically, and he was able to swallow food without a nasal feeding tube. The AChRAb titer decreased from 42.4 to 23.4 nmol/l during the treatment period. The concentration of tacrolimus in whole blood was 7.0 ng/ml 6 days after the initiation of treatment. These findings suggest that tacrolimus is effective in intractable and elderly MG patients.

Adult↗

Steroid-induced diabetes mellitus and related risk factors in patients with neurologic diseases.

STUDY OBJECTIVE: To determine the frequency of steroid-induced diabetes mellitus (SDM) and the related risk factors in patients with neurologic diseases who receive high doses of steroids. DESIGN: Retrospective chart review. SETTING: Neurology ward of a university-affiliated hospital. PATIENTS: Twenty-five patients with neurologic diseases who received prednisolone 30-60 mg/day orally after breakfast for more than 2 weeks. MEASUREMENTS AND MAIN RESULTS: Plasma glucose concentrations were determined immediately before and 2 hours after each meal. Steroid-induced diabetes mellitus was diagnosed if the patient had either a fasting glucose concentration of 126 mg/dl or greater, or a random glucose concentration of 200 mg/dl or greater. The patients were divided into two groups on the basis of whether SDM had developed (13 patients) or not (12 patients). Ages, body mass indexes, cumulative total doses and daily doses of prednisolone, duration of therapy, and serum cholesterol and triglyceride concentrations were compared between the groups. Thirteen of the 25 patients were identified with SDM, and all of them had plasma glucose concentrations of 200 mg/dl or greater 2 hours after lunch. Mean age (59.1 +/- 10.2 yrs) and cholesterol concentration after prednisolone treatment (226.8 +/- 36.4 mg/dl) in the SDM group were significantly higher than those values in the non-SDM group (41.3 +/- 18.0 yrs and 188.1 +/- 27.2 mg/dl, respectively, p<0.01). CONCLUSIONS: A close relationship among postprandial hyperglycemia, advanced age, and hypercholesterolemia is a characteristic of SDM in patients with neurologic diseases. Therefore, monitoring the plasma glucose concentration 2 hours after lunch may be useful to detect SDM in these patients.

Adult↗

[Essential points to differentiate various diseases causing parkinsonism].

This review article deals with the cardinal features to differentiate various conditions which present with parkinsonism other than Parkinson's disease. Special attention is paid to the distinctive clinical features, laboratory data and neuroimaging findings of frequent diseases as well as important ones including multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration, Lewy body disease, drug-induced parkinsonism, vascular pseudo-parkinsonism, normal pressure hydrocephalus and manganese intoxication due to parenteral nutrition. MRI is useful to diagnose MSA, vascular pseudo-parkinsonism and manganese intoxication. Benzamide derivatives including sulpiride and metoclopramide are the main causes of drug-induced parkinsonism in recent years in Japan.

Humans↗