[Autopsied case of Parkinson disease with neuroleptic malignant-like syndrome and rhabdomyolysis].
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Acute Kidney Injury↗
Biomedical subjects
T Ishizaki
Publications and source records attributed to T Ishizaki.
[Drug interactions in combination drug therapy].
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Drug Interactions↗
Simultaneous determination of omeprazole and its metabolites in plasma and urine by reversed-phase high-performance liquid chromatography with an alkaline-resistant polymer-coated C18 column.
Omeprazole (OPZ) is a proton pump inhibitor in gastric parietal cells. A reversed-phase high-performance liquid chromatographic method was developed that enables concentrations of OPZ and its major metabolites, omeprazole sulphone (OPZ-SFN) and hydroxy-omeprazole (H-OPZ), to be determined simultaneously in plasma and that of H-OPZ in urine. To prevent decomposition of OPZ, all the processes (extraction, injection and elution) were carried out under alkaline conditions. Recoveries of the analytes and internal standard were greater than 93.1%. The intra- and inter-assay coefficients of variation were less than 9.1 and 6.4% for plasma samples and less than 2.9 and 3.9% for urine samples, respectively. The minimum determinable concentration (relative standard deviation 10-15%) was 10 ng/ml for all analytes in plasma and H-OPZ in urine samples. The clinical applicability of this assay method was evaluated by determining plasma concentration-and urinary excretion-time courses of the respective analyte(s) in four healthy volunteers after an oral dose of 20 mg of OPZ. The present assay is considered to be simple, precise and accurate and suitable for the study of the kinetic disposition and metabolism of OPZ, which is an extensively metabolized drug in the human liver.
Adult↗
Acute effect of an alpha 1-adrenoceptor antagonist on urinary sodium excretion, plasma atrial natriuretic peptide, arginine vasopressin, and the renin-aldosterone system in healthy subjects.
To elucidate the mechanism underlying the sodium retention caused by alpha 1-adrenoceptor blockade in man, a placebo-controlled, randomised, double-blind study has been made of the acute effects of bunazosin an alpha 1-antagonist, on urinary sodium excretion, atrial natriuretic peptide (ANP), arginine vasopressin (AVP), and the renin-aldosterone system in 7 healthy men. A single oral dose of bunazosin 2.0 mg caused a significant reduction (P less than 0.05) in urinary sodium excretion after 0-2 h, 2-4 h, and 4-6 h. The mean values for plasma ANP, AVP, aldosterone, and cortisol concentrations at those times were similar after placebo and bunazosin, and plasma renin activity was significantly increased 2 and 4 h after bunazosin. Pretreatment with oral enalapril 10 mg, an angiotensin converting enzyme inhibitor, did not prevent the bunazosin-induced reduction in urinary sodium excretion. There was a significant positive correlation between the drug-induced changes in blood pressure and urinary sodium excretion. The results suggest that ANP, AVP, and renin-aldosterone may play little role in the sodium retention caused by acute alpha 1-adrenoceptor blockade in man.
Adrenergic alpha-Antagonists↗
Incidence of S-mephenytoin hydroxylation deficiency in a Korean population and the interphenotypic differences in diazepam pharmacokinetics.
We studied the genetically determined hydroxylation polymorphism of S-mephenytoin in a Korean population (N = 206) and the pharmacokinetics of diazepam and demethyldiazepam after an oral 8 mg dose of diazepam administered to the nine extensive metabolizers and eight poor metabolizers recruited from the population. The log10 percentage of 4-hydroxymephenytoin excreted in the urine 8 hours after administration showed a bimodal distribution with an antimode of 0.3. The frequency of occurrence of the poor metabolizers was 12.6% in the population. In the panel study of diazepam in relation to the mephenytoin phenotype, there was a significant correlation between the oral clearance of diazepam and log10 urinary excretion of 4-hydroxymephenytoin (rs = 0.777, p less than 0.01). The plasma half-life of diazepam in the poor metabolizers was longer than that in the extensive metabolizers (mean +/- SEM, 91.0 +/- 5.6 and 59.7 +/- 5.4 hours, p less than 0.005), and the poor metabolizers had the lower clearance of diazepam than the extensive metabolizers (9.4 +/- 0.5 and 17.0 +/- 1.4 ml/min, p less than 0.001). In addition, the plasma half-life of demethyldiazepam showed a statistically significant (p less than 0.001) difference between the extensive metabolizers (95.9 +/- 11.3 hours) and poor metabolizers (213.1 +/- 10.7 hours), and correlated with the log10 urinary excretion of 4-hydroxymephenytoin (rs = -0.615, p less than 0.01). The findings indicate that the Korean subjects have a greater incidence of poor metabolizer phenotype of mephenytoin hydroxylation compared with that reported from white subjects and that the metabolism of diazepam and demethyldiazepam is related to the genetically determined mephenytoin hydroxylation polymorphism in Korean subjects.
Adult↗
Effects of a sustained thromboxane synthase inhibition on exercise-induced changes in eicosanoid formation, catecholamine concentration, and platelet aggregation in humans.
In an effort to characterize an interaction between the eicosanoids and sympathoadrenal system on platelet aggregation, we tried to determine if a sustained thromboxane A2 (TXA2) synthase inhibition would modulate changes in eicosanoid formation, catecholamine concentration, and platelet aggregation induced by a physical stress. We measured thromboxane B2 (TXB2), 11-dehydro-TXB2, 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), norepinephrine, and epinephrine in vivo and platelet aggregation ex vivo before and after a treadmill exercise with and without the oral doses (400 mg twice daily for 7 days) of a new selective TXA2 synthase inhibitor (DP-1904) in nine healthy male subjects. The exercise tests performed on the pretreatment day (day 0) and posttreatment day (day 7) gave a similar result. DP-1904 caused a decrease in serum and urinary TXB2 and urinary 11-dehydro-TXB2 (p less than 0.001 to p less than 0.01) and an increase in serum 6-keto-PGF1 alpha (p less than 0.001 to p less than 0.05) throughout the dosing interval on days 4 and 7. Despite the drug effect on eicosanoid formation at rest and after exercise, the exercise-induced plasma norepinephrine and epinephrine concentrations did not differ between days 0 and 7. The 7-day treatment decreased (p less than 0.01) platelet aggregation induced both by adenosine diphosphate and by collagen at rest. However, the exercise increased (p less than 0.01) platelet aggregation by the two aggregators, resulting in the disappearance of the drug-induced antiaggregatory effects observed at rest. The treatment with a TXA2 synthase inhibitor does not appear to attain the antithrombotic action during an exercise despite the occurrence of a sustained endoperoxide shunting.
6-Ketoprostaglandin F1 alpha↗
Steady-state pharmacokinetics and bioavailability of total and unbound disopyramide in children with cardiac arrhythmias.
We studied the pharmacokinetics of the total (protein-bound plus -unbound and unbound forms of disopyramide (DP) at steady-state in six children (aged 5.2 to 12.2 years) with cardiac arrhythmias who had received repeated oral DP therapy. Maximum concentrations after the oral dose were reached at 2.5 +/- 1.1 h (mean +/- SD) for both total and unbound DP. The bioavailabilities calculated from total and unbound plasma concentration-time curves were 99 +/- 23 and 89 +/- 27% of the dose, respectively. These parameters seen in our children are similar to those reported from adult subjects. The mean elimination half-lives (t1/2), volumes of distribution, and total body clearances (CL) of total and unbound DP were 3.15 +/- 0.64 and 2.50 +/- 0.37 h, 1.02 +/- 0.25 and 2.60 +/- 0.38 L/kg, and 3.79 +/- 0.82 and 13.12 +/- 2.60 ml/min/kg, respectively. These mean CL and t1/2 values are considerably greater and shorter, respectively, than those reported from adult subjects. The findings indicate that the greater doses of DP per kg of body weight reportedly required for attaining a therapeutic plasma drug level in pediatric age patients should be due to a greater drug CL in children than in adults. A sustained-release preparation of DP may be required for pediatric patients to minimize a large fluctuation of plasma drug levels during the dosing intervals.
Arrhythmias, Cardiac↗
Utility of a one-point (3-hour postdose) plasma metabolic ratio as a phenotyping test using metoprolol in two east Asian populations.
We examined the utility of the postdose 3-h plasma metabolic ratio (MR) as a phenotyping method for assessing genetically determined debrisoquine-type oxidation polymorphism after an oral dose of 100 mg of metoprolol tartrate administered to 402 unrelated, healthy, and native East Asian (218 Korean and 184 Japanese) subjects. All of them were phenotyped simultaneously with the reported MR employing urine samples collected during an 8-h postdose period. In the two populations, the distribution histograms and probit plots of log10plasma MRs derived from the metoprolol/alpha-hydroxymetoprolol concentration values indicated a large gap between the extensive and poor metabolizers who were phenotyped by the reported criteria of the 8-h urinary MR. There were statistically significant (p less than 0.001) correlations (rs = 0.688 and 0.810, respectively) between the postdose urinary and plasma MRs in the Korean and Japanese populations. Two poor metabolizers (one each included in the two racial groups) identified according to the 8-h urinary MR gave the greatest plasma MRs (i.e., 549.7 among the Koreans and 150.0 among the Japanese). The results suggest that the one-point, postdose 3-h plasma MR is also useful for the phenotyping purpose of oxidation pharmacogenetic polymorphism of metoprolol, a widely prescribed beta-adrenoceptor blocking drug.
Adolescent↗
Recent advances in pharmacological management of hypertension in diabetic patients with nephropathy. Effects of antihypertensive drugs on kidney function and insulin sensitivity.
Hypertension is often seen in Type 1 and Type 2 diabetic patients, particularly in those with nephropathy, and the progression of diabetic nephropathy is closely related to blood pressure elevation. Thus, the effects of antihypertensive drugs on kidney function and insulin sensitivity in diabetic patients are of great clinical importance. Successful antihypertensive treatment has been shown to slow the progression of diabetic nephropathy. Several results from short term studies have suggested that angiotensin converting enzyme (ACE) inhibitors may be advantageous over other conventional antihypertensive agents in reducing albuminuria in both hypertensive and normotensive diabetics with microalbuminuria or persistent proteinuria. However, the decline in glomerular filtration rate during ACE inhibitor treatment is comparable to that during effective treatment with conventional antihypertensive drugs in hypertensive Type 1 diabetic patients with overt nephropathy. Whether ACE inhibitors possess a specific effect in preventing the development of diabetic nephropathy remains to be seen in properly designed long term studies. Although calcium antagonists may preserve kidney function or possess a renoprotective effect in hypertensive Type 2 diabetics with nephropathy, firm evidence supporting this contention seems to be lacking and also requires long term evaluation. Increasing attention is being directed toward the effect of antihypertensive drugs on insulin sensitivity in diabetic patients: ACE inhibitors and alpha 1-adrenoceptor blocking agents have been shown to improve this sensitivity. Despite the widespread involvement of calcium in hormone secretion and action, calcium antagonists appear to have little effects on the glucoregulatory and calcium-regulatory hormones within the drug dosages used in clinical practice. Several clinical variables, such as the presence or absence of hypertension, overt nephropathy and microalbuminuria, or a combination of variables should be accounted for when evaluating critically the cumulative data on the effects of antihypertensive drugs on kidney function and albuminuria in the variety of diabetic patient groups. Understanding the pharmacokinetic and pharmacodynamic characteristics of antihypertensive drugs will be of clinical importance in diabetic patients with advanced nephropathy (glomerular filtration rate of less than 30 ml/min) and/or other complications, such as impaired gastric motility or gastroparesis, and will thereby lead to a more rational management of hypertension in those patients.
Antihypertensive Agents↗
[Drug therapy in the elderly].
The elderly are known to be more susceptible to adverse drug reactions. Age differences in pharmacokinetics (i.e., absorption, distribution, metabolism, and elimination) may contribute to an increased susceptibility of the elderly to both the therapeutic and toxic effects of some drugs. For many drugs studied, such pharmacokinetic differences are generally consistent with age differences in body composition, renal function, and protein binding. Ageing is associated with a decrease in lean body mass and total body water, and a decline in glomerular and tubular function in the kidney, and diminished cardiac output and liver blood flow. In addition to considering the epidemiology of adverse drug reactions and the altered physiology and pharmacokinetics in the elderly, this review attempts to provide an overview of what is known about the relationship between advanced age and the pharmacokinetics of some drugs mainly eliminated via the kidney. Thus, several methods are presented to permit rational dosage regimen modifications for elderly patients with diminished renal function. Based on a review of the accumulated literature related to clinical geriatric pharmacology, it is concluded that dosage regimen adjustments based on therapeutic drug monitoring are essential to make drug therapy in the elderly safer and more effective.
Aged↗
[Theophylline toxicity in a patient with status asthmaticus].
A 70-year-old woman was hospitalized for status asthmaticus. The level of CRP was high and chest roentgenogram showed infiltrative shadows in the left middle lung field. Artificial respiration and continuous infusion of methylprednisolone and aminophylline 750 mg/24 hr were performed. Eight hours after admission, seizures suddenly occurred. At this time, brain CT showed no abnormal findings. The seizures were thought to be induced by theophylline toxicity, since serum theophylline concentration was high at 69.9 micrograms/ml. Because theophylline clearance of the patient in a clinically stable condition was normal, it was speculated that theophylline clearance was reduced during status asthmaticus. It is thought that this rare case of theophylline toxicity occurred due to reduction of theophylline clearance during status asthmaticus associated with pneumonia.
Aged↗
A study on conformationally restricted sangivamycins and their inhibitory abilities of protein kinases.
Conformational restrictions of sangivamycin, a rather selective inhibitor of PKC, could be achieved by the use of the steric effect and the gauche effect of the substituents on the ribofuranose moiety. The conformational deviations obtained by these methods were found to nicely correlate with the inhibitory ability of PKC.
Anti-Bacterial Agents↗
[A case of Fabry's disease associated with lupus nephritis].
A 36-year-old woman was hospitalized because of nephrotic syndrome. On admission, laboratory studies revealed total protein 5.9g/dl, total cholesterol 381mg/dl, urine protein 2-4g/day, C3 68mg/dl(90-185mg/dl) and the immunological tests showed that antinuclear factor, anti-DNA antibodies and the LE cell phenomenon were positive. Renal function was within normal range. After admission, renal biopsy was done. Light microscopic finding showed diffuse membranous glomerulonephritis, and vacuolization of epithelial cells. Immunofluorescent microscopic finding showed a granular specific staining for IgG, IgM, C3 and C1q along the capillary loops. Electron microscopic finding showed subepithelial and subendothelial dense deposits, and visceral epithelial cell cytoplasm containing osmiophilic multilamellar lipoid bodies. In the studies of the enzyme activities, the patient's fibroblast extract demonstrated a partial deficiency of alpha-galactosidase, and urine ceramide trihexoside was positive. But the patient's leukocyte extract did not demonstrate a deficiency of alpha-galactosidase. So Fabry's disease associated with lupus nephritis was diagnosed. It seems that the case of Fabry's disease which is an X-linked disorder caused by deficiency of the lysosomal enzyme alpha-galactosidase, associated with lupus nephritis, is extremely rare.
Adult↗
[Bronchial hyperresponsiveness to acetylcholine during acute pulmonary congestion in guinea pigs].
To understand the precise mechanism of bronchial hyperresponsiveness in patients with congestive heart failure, we studied the effect of mild pulmonary congestion on bronchial responsiveness to inhaled acetylcholine (ACh) in guinea pigs. We induced mild pulmonary congestion by inflation of a balloon placed in the left atrium, and maintained the left atrial pressure (Pla) at 10 mmHg for 30 minutes with continuous monitoring of lung resistance (RL) and dynamic compliance (Cdyn). Furthermore, we determined the provocative concentration of ACh producing 100% increase in RL (PC100-ACh), before and during balloon inflation. In animals with propranolol pretreatment, but not in animals without propranolol pretreatment, mild pulmonary congestion caused slight increase in RL (N.S.) and significant decrease in Cdyn (p less than 0.01) and PC 100-ACh (p less than 0.01). Cutting of bilateral vagal nerves partially inhibited the decrease of PC100-ACh, but pretreatment with either phenoxybenzamine, indomethacin, AA-861 or OKY-046 had not effect. These results suggest that blockade of beta-adrenergic receptors and the vagal reflex, but not of alpha-adrenergic receptors or arachidonates, contributes to bronchial hyperresponsiveness during acute pulmonary congestion.
Acetylcholine↗
Caution in the use of a 100 mg dose of racemic mephenytoin for phenotyping southeastern Oriental subjects.
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Adult↗
[Probucol inhibits tobacco smoke-induced decrease in plasma anti-elastase activity and ferroxidase activity in rats].
Elastolytic enzymes and active oxygen species derived from leukocytes and alveolar macrophages during exposure to tobacco smoke, together with active oxygen species directly derived from tobacco smoke, are thought to play a crucial role in the pathogenesis of pulmonary emphysema by inactivating alpha 1 protease inhibitor (alpha 1 PI), a novel anti-elastase. We studied the inhibitory effect of probucol, an oral hypocholesterolemic agent, on tobacco smoke-induced decrease in plasma anti-elastase activity (EIA) and ferroxidase activity (FA) in conscious venous catheter instrumented rats. Rats exposed to the smoke of 5 cigarettes (nicotine 11 mg, tar 115 mg) in a plastic chamber showed a prompt increase in plasma COHb to 17.9 +/- 2.7%, and a prompt decrease in plasma EIA by -17.9% (p less than 0.05) and FA by -14.8% (p less than 0.01), which lasted for 6 hours after exposure. Rats administered probucol (1% probucol in food) for 3 days showed normal cholesterol plasma levels, and rats administered probucol for 4 weeks showed hypocholesterolemic plasma levels. EIA and FA were not depressed after smoking, and lipid peroxide product (TBA reactive substance) in lung tissue (p less than 0.05) and serum (p less than 0.1) showed a smaller increase in association with a smaller decrease in the ratio of lung tissue GSH/GSSG (p less than 0.01) compared with control rats. These results indicate that probucol, via its antioxidant action rather than its cholesterol lowering effect, has a protective effect on lung exposed to tobacco smoke in terms of protease-antiprotease balance and oxidant-antioxidant balance.
Animals↗
[Effects of inhaled and intravenous furosemide on bronchial hyperresponsiveness in patients with chronic congestive heart failure].
We studied the effects of inhaled and intravenous furosemide (40 mg) on bronchial responsiveness to acetylcholine (ACh) in patients with chronic congestive heart failure. The measurement of bronchial responsiveness was performed by inhaling doses of ACh and calculating the provocative concentration of ACh needed to cause a 20% fall in FEV1.0 (PC20-ACh). Intravenous furosemide (N = 11) had a marked diuretic effect (urine output 1014 ml (SEM 156) in 2 hours), but had no effect on resting pulmonary function and PC20-ACh. In contrast, inhaled furosemide (N = 10) had no effect on urine output and resting pulmonary function, but caused significant increase in PC20-ACh from 2.74 (GSEM 1.28) to 8.47 (GSEM 1.22) mg/ml (p less than 0.05). We conclude that inhaled furosemide, but not intravenous furosemide reduces bronchial hyperresponsiveness to ACh in patients with chronic congestive heart failure. The mechanism of this effect appears to be related to the ion transport system of airway epithelium.
Administration, Inhalation↗
[A study of skin test with regard to age differences and agreement with positive results from the RAST and ELISA methods].
Skin tests of the scratch type were performed on 132 asthmatic patients with 28 allergens. The threshold titers of skin test, RAST and ELISA of house dust, HD mites, Japanese cedar pollen, ragweed pollen and orchard grass pollen were included. The main skin-positive allergens among the patients were as follows: house dust, HD mites, Japanese cedar pollen, orchard grass pollen, timothy grass pollen and ragweed pollen. There are age differences on skin-positive rates among 4 age groups of the patients; 90% of the patients under 40 years old groups reacted positively to any of 28 allergens, while half number of the patients groups over 40 years old reacted positively to the allergens. According to the quantitative analysis between threshold titers of skin test and RAST titers using house dust and HD mites allergens, specific IgE production shall be decreased in the patients over 40 years old. Using 5 main allergens above mentioned, the agreements of positive responses between three methods were compared. RAST positive responses correlated well with the skin test results, while ELISA positive responses correlated rather poorly with the skin test results. However, correlation between RAST and ELISA results was relatively good. The correlation of positive responses to house dust and HD mites by the three methods was very good, but there were some cases where positive responses were obtained by only one of the methods.
Adolescent↗