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Biomedical subjects

N Takemura

Publications and source records attributed to N Takemura.

At least 37 records · Page 2Linked to original sources

Plasma atrial natriuretic peptide in normal calves during the first 10 days of life.

The concentration and molecular form of the plasma atrial natriuretic peptide (ANP) in normal calves during the first 10 days of life were investigated. The mean (SEM) ANP concentration on the day of birth was 62.7 (5.52) pmol litre-1, and thereafter it decreased progressively and significantly (P < 0.001). After 10 days, the plasma ANP concentration had decreased to normal adult values (11.3 [3.87] pmol litre-1). On the day of birth and 10 days later a single peak corresponding to alpha-ANP alone was detected in the plasma of the calves.

Aging↗

Brain abscess due to infection with Entamoeba histolytica.

We successfully treated a serious case of Entamoeba histolytica infection showing brain abscess, meningitis, and liver abscess by oral administration of metronidazole, intramuscular injection of dehydroemetine, and drainage of the brain abscess. The diagnosis of amebic brain abscess was based on a combination of clinical symptoms and signs, computed tomography and magnetic resonance imaging findings, a positive serologic test result for E. histolytica, a dramatic response to anti-amebic drugs after an ineffective therapeutic history with antibacterial drugs, and application of the polymerase chain reaction method.

Administration, Oral↗

Cerebral retroflexion in holoprosencephaly developed following ventriculo-peritoneal shunting: a case report.

Retroflexion of the hypoplastic fused cerebrum is a rare condition in holoprosencephaly. We describe a new case of this entity in a 7-year-old boy with alobar holoprosencephaly whi developed retroflexion of the holosphere 7 years after a ventriculo-peritoneal shunt was placed. The radiological findings revealed retroflexion of the cerebrum anchored to the cranial vault between the precerebral space and the dorsal sac, which were open to each other. In patients with holoprosencephaly, the possibility of retroflexion of the holosphere should be considered after placement of a ventriculo-peritoneal shunt for associated hydrocephalus.

Brain↗

Immunochemical characterization and localization of endothelin ETB receptor.

A highly specific antiserum was raised against purified bovine endothelin ETB receptor and used to determine the tissue distribution of the receptor subtype ETB and to localize the receptor immunohistochemically in the kidney, adrenal gland, lung, cerebellum, and pituitary gland whose functions are known to be under strong influence of endothelin. The antiserum raised in a rabbit specifically recognized the receptor band on Western blot analysis of membrane proteins. Furthermore, it immunoprecipitated only ETB, establishing its ETB specificity. By determination of the percentage of the total number of the endothelin receptors that is immunoprecipitable with the antiserum, the amounts of the ETB relative to those of the ET receptors were found to vary from tissue to tissue: lung (70%), cerebellum (55%), pituitary gland (50%), kidney (25%), adrenal gland (10%), and testis (< 2%). This means that, in the lung, ET is the major form, whereas in the testis, ETA is predominant, comprising >95% of the receptors. Immunohistochemical examination of tissue sections revealed endothelium localization of the ETB endothelin receptor.

Adrenal Glands↗

Changes of plasma osmotic pressure during lactation in rats.

It is known that blood and plasma volume increase during lactation. The present paper examines whether an increase in plasma volume is accompanied by the change in plasma composition or attributed to hydro-dilution. Six dam-nursed pups and six dam-removed pups housed individually were designated as lactating rats and control rats, respectively. The plasma osmotic pressure and hematocrit value (Ht) were measured in the rats on days 3, 5, 7, 10, 13 and 18 of lactation. The total plasma protein (TP) and serum sodium concentration were also measured as they are factors affecting the plasma osmotic pressure. In addition, milk yield was estimated by the Morag technique. On day 5 and after day 10, the osmotic pressure of the lactating rats was found to be significantly lower than that of the control rats. The serum sodium concentration (days 5 and after day 10) and Tp values (days 3, 10 and 18) of the lactating rats were significantly lower than those of the control rats. Except on day 5, the Ht values of the lactating rats were significantly lower than those of the controls. During the period between days 3 and 10, milk yield was increased and it become steady (18 g/12 hr) on days 10 and 18. On and after day 10 when rats secreted a large amount of milk, it is considered that a decrease in the plasma osmotic pressure was mainly attributed to the reduction of sodium concentration by hydro-dilution. The Ht values indicate that an increase in blood volume is mainly through plasma volume rather than blood cell volume in lactating rats.

Animals↗

Cerebral cysticercosis.

A 44-year-old female underwent a right frontal craniotomy under a diagnosis of metastatic brain tumor and a fluid-filled cystic lesion was extirpated. One rice grain sized nodule was identified in the cyst and histopathological examination of the nodule showed a scolex with hooks and suckers. These macro and microscopic findings indicated a diagnosis of cerebral cysticercosis, caused by infection of the larval stage of some type of Taenia species. A therapeutic course of praziquantel was given after craniotomy. The patient has been a resident of the Kanto area of Japan since birth and has never been outside Japan.

Adult↗

Atrial natriuretic peptide in the dog with mitral regurgitation.

The concentration and molecular form of the plasma atrial natriuretic peptide (ANP) in dogs with mitral regurgitation was investigated. Plasma ANP concentration in dogs with mitral regurgitation was significantly increased (29.4 +/- 1.88 pmol litre-1, n = 40) compared to that in the controls (14.5 +/- 0.62 pmol litre-1, n = 20, P less than 0.01). Molecular forms of plasma ANP were determined by the gel permeation chromatogram. A single peak corresponding to alpha-ANP was detected in the plasma from the controls. However, a peak corresponding to beta-ANP and, or, gamma-ANP was detected in the plasma of the dogs with mitral regurgitation in addition to alpha-ANP. These results suggest that the process of ANP synthesis was altered and excretion of ANP from the heart was enhanced in dogs with mitral regurgitation.

Animals↗

Glycated hemoglobin fractions in normal and diabetic dogs measured by high performance liquid chromatography.

We established a new analytical condition to measure the canine glycated hemoglobin by high performance liquid chromatography (HPLC) using cation exchange column. The canine hemoglobin gave five peaks consisting of 2 major and 3 minor hemoglobin fractions such as HbA1a, HbA1b and HbA1c. Measurement was done in 38 clinically normal dogs and 10 diabetic dogs. Mean HbA1c values (% of total Hb) in normal and diabetic dogs were 2.60 and 6.41%, respectively. And mean HbA1 values were 3.58 and 7.41%, respectively. The mean values of the canine HbA1c and HbA1 in diabetic dogs was higher than those in normal dogs, significantly (p less than 0.01). Advantages of the HPLC method and applicability for monitoring effectiveness of insulin therapy in the canine diabetes mellitus are discussed.

Animals↗

Brain natriuretic peptide is cosecreted with atrial natriuretic peptide from porcine cardiocytes.

Using primary cultures of atrial cardiocytes from neonatal pig, the secretion brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP)-like immunoreactivities (LI) was studied in vitro. Porcine cardiocytes time-dependently secreted both BNP-LI and ANP-LI into medium under a serum-free condition, although the amount of BNP-LI secreted was about one-third that of ANP-LI. Phorbol ester and Ca2+ ionophore had less stimulatory effects on secretion of BNP-LI than that of ANP-LI. Reverse-phase HPLC of the conditioned medium revealed a single major BNP-LI component corresponding to synthetic porcine BNP(1-26). These data suggest that a small molecular weight form BNP, possibly BNP(1-26), is cosecreted with ANP from porcine cardiocytes.

Animals↗

An enzymatic assay method for D(-)-3-hydroxybutyrate and acetoacetate involving acetoacetyl coenzyme A synthetase from Zoogloea ramigera.

An enzyme assay method for D(-)-3-hydroxybutyrate and acetoacetate involving acetoacetyl coenzyme A (CoA) synthetase was developed. To determine the concentration of D-3-hydroxybutyrate, it was oxidized with D-3-hydroxybutyrate dehydrogenase in the presence of nicotinamide adenine dinucleotide (NAD+) to acetoacetate, which was then converted to acetyl CoA via acetoacetyl CoA through the combined actions of acetoacetyl CoA synthetase and 3-ketothiolase in the presence of adenosine triphosphate (ATP) and CoA. To determine the concentration of acetoacetate, acetoacetyl CoA generated from acetoacetate with acetoacetyl CoA synthetase was reduced to 3-hydroxybutyryl CoA with 3-hydroxyacyl CoA dehydrogenase in the presence of NADH. The amount of D-3-hydroxybutyrate or acetoacetate was estimated from the increase or decrease in the absorbance at 340 nm, respectively. The present assay method seemed to be accurate and quick. Furthermore, as to the assaying of D-3-hydroxybutyrate, the omission of hydrazine, which is included for the standard method, may be preferable for routine assaying.

3-Hydroxybutyric Acid↗

Bovine atrial natriuretic peptide in heart failure.

The present study describes the concentration and molecular form of atrial natriuretic peptide (ANP) in Holstein dairy cattle with mild (bacterial endocarditis; BEC) or severe (dilated cardiomyopathy; DCM) heart failure. Significant increases in plasma concentration of ANP were observed in cattle with DCM (73.3 +/- 16.02 pmol/l, n = 4, P less than 0.01) and BEC (20.6 +/- 3.45 pmol/l, n = 7, P less than 0.05), when compared with those in control cattle (14.5 +/- 1.84 pmol/l, n = 12). The concentration of ANP in cattle with DCM was significantly (P less than 0.01) higher compared with that in cattle with BEC. Plasma concentration of ANP correlated significantly with right atrial pressure (r = 0.95, P less than 0.01) and left ventricular end-diastolic pressure (r = 0.84, P less than 0.01). Gel-permeation chromatography of ANP in plasma and the right atrium from control and cattle with BEC revealed a single peak corresponding to the elution position of authentic human ANP(99-126) in plasma, and two peaks corresponding to those of authentic human ANP(99-126) and pro-ANP in the atrial extract. In cattle with DCM, however, peaks corresponding to the elution positions of authentic human beta-ANP and/or pro-ANP were detected in addition to the peak corresponding to ANP(99-126). The content of ANP in the right atrium of cattle with DCM was significantly (P less than 0.05) increased compared with that in control cattle and those with BEC. The present study therefore suggests that the synthesis and secretion of ANP might be stimulated by atrial distention induced by increased atrial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effects of butoctamide hydrogen succinate and nitrazepam on psychomotor function and EEG in healthy volunteers.

We studied the effects of butoctamide hydrogen succinate and nitrazepam on psychomotor function and EEG in eight male volunteers aged 19-32. The hypnotic effects, effects on psychomotor performance, EEG activity and standing steadiness between BAHS 1000 mg and nitrazepam 5 mg were compared at regular intervals for 10 h. The serum levels of both drugs were also assayed. The hypnotic effects of BAHS were very weak compared to those of nitrazepam. BAHS did not exert any effects on psychomotor performance and standing steadiness during the test period. In contrast, nitrazepam impaired psychomotor performance and standing steadiness as the serum drug levels increased. Nitrazepam decreased the alpha activity and increased the beta activity in a concentration-dependent manner. BAHS did not change the alpha activity but increased beta-2 activity at Fz and Cz at 10 h of the post-drug period. BAHS was eliminated more rapidly than nitrazepam. These results indicated that BAHS, at the dose used, was less potent than nitrazepam and the effects on psychomotor performance and standing steadiness were minimal.

Acoustic Stimulation↗

Pharmacokinetics of quinidine sulfate in dairy cattle.

Pharmacokinetic profile and therapeutic range of plasma quinidine concentration were determined in dairy Holstein cows. Plasma half-life of intravenous quinidine was 1.28 +/- 0.492 (0.41-1.65) hr. The pattern of plasma quinidine transition after oral administration varied greatly among individuals. Total body clearance was 58.7 +/- 24.49 ml/min/kg, although renal quinidine clearance was 0.76 +/- 0.441 ml/min/kg. Therefore, the involvement of some extrarenal organ as the main site of excretion was suspected. Seven cows, diagnosed as atrial fibrillation or ventricular premature contraction, were orally administered with quinidine at various dosages. They showed plasma concentration of 2.3 +/- 1.59 mg/l when therapeutic effect was observed. Clinical signs of intoxication were observed at plasma quinidine concentrations over 10 mg/l. These results suggest the difficulty with the maintenance of effective plasma quinidine concentration by an oral or a single intravenous administration, and thus it is concluded that use of quinidine for treatment arrhythmic cows must be carefully done in order to avoid possible intoxication.

Administration, Oral↗

Myocarditis with myocardial infarction like findings in a 3-year old girl.

A 3 year-old Japanese girl had an acute onset associated with vomiting. The electrocardiogram (ECG) indicated changes similar to those of acute myocardial infarction (MI); there was no past history of kawasaki disease. Selective coronary angiography taken on the 28th day of illness revealed no abnormality. Thallium 201 scintigraphy was also performed and it revealed that the area of absent myocardial uptake was in the anterior wall. In serological findings, antibody titers against Coxsackie B-3 virus had risen significantly; therefore acute myocarditis caused by Coxsackie B-3 virus infection was diagnosed.

Antibodies, Viral↗