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Biomedical subjects

H Maeda

Publications and source records attributed to H Maeda.

At least 595 records · Page 33Linked to original sources
PubMed1994

Distemper skin lesions in a dog.

Skin lesions were studied in a 3-year-old male Maltese dog with distemper. Hyperkeratosis and parakeratosis with vesicles and pustule formation were the outstanding features of the skin lesions around the eye, nose, and mouth. Multinucleated syncytial giant cells together with nuclear and cytoplasmic inclusion bodies containing viral particles and viral antigen were scattered in the epidermis, and epidermal appendages. These findings suggest a direct viral attack on the skin.

Animals↗
PubMed1994

A theoretical and neurophysiological consideration on the pathogenesis of positive symptoms of schizophrenia: implications of dopaminergic function in the emotional circuit.

The implications of the emotional circuit and the gating mechanism by dopamine (DA) proposed by Maeda in the pathogenesis of positive symptoms of schizophrenia were reconsidered based upon recent advances and findings in the fields of neurophysiology and neuropharmacology and in biological studies of schizophrenia. The gating mechanism by DA was partly supported by new evidence that glutamatergic or GABAergic neurotransmission, which mediates the hippocampo-lateral septal or the piriform cortico-amygdaloid neuronal connections, is likely to be modulated by DA. The compensation-facilitating or gating functions of DA was considered again to play an important role in producing positive symptoms in schizophrenics, who have been suggested to have morphological abnormalities in the limbic system or in the prefrontal cortex prior to the appearance of positive symptoms.

Brain↗
PubMed1994

Autologous blood transfusion for the patient with placenta previa complicated by placenta increta: a case report.

The patient, who was 34 years of age, had previously had a transverse incision of the lower uterine segment cesarean section because of placenta previa. She was admitted to the hospital due to placenta previa again at 27 weeks of gestation in the current pregnancy. Ultrasound examination revealed placenta increta as well as placenta previa. In an attempt to avoid homologous blood transfusion at the time of profuse hemorrhage anticipated to occur during cesarean section, an autologous blood transfusion was planned. Fifteen hundred ml of autologous blood was collected by a leap-frog method during the 8 weeks prior to cesarean section. A cesarean hysterectomy was performed at 37 weeks of gestation because of placenta increta. Blood loss was estimated at 1,830 ml, and 1,500 ml of autologous blood was transfused. A leap-frog method of autologous blood collection for this pregnant woman with risk of massive hemorrhage was simple and beneficial, resulting in the preservation of more than 1,500 ml of autologous blood for transfusion.

Adult↗
PubMed1994

Keratin staining pattern in clinically normal and diseased oral mucosa of lichen planus patients.

The keratin pattern in oral epithelia is related to the type of terminal differentiation observed morphologically (keratinization/nonkeratinization) and to the presence or absence of epithelial dysplasia. Furthermore, it has been suggested recently that inflammatory phenomena influence the keratin expression in human gingiva. The aim of the present study was to describe the keratin pattern in oral lichen planus (OLP) lesions, which are well known to be characterized by hyperkeratinization and severe inflammatory changes, in order to elucidate the role of inflammation in keratin expression of oral epithelia. Tissue sections were stained with antikeratin antibodies directed to groups of keratins (AE1 and AE2) and to single keratin proteins (Nos. 5, 8, 13, and 19). The keratin pattern in OLP lesions differed in some respects from that of leukoplakias and frictional keratoses as characterized in previous studies. No consistent patterns for use in a diagnostic context were found. However, the changes in OLP lesions did not mimic those previously described in inflamed gingival specimens and in oral epithelial dysplasias. Thus, the results encourage further studies on the potential diagnostic use of keratin expression in premalignant oral lesions. Furthermore, the study suggests that the inflammatory reaction seen in OLP lesions does not influence keratin expression in a way comparable with the suggested influence of inflammation in gingival specimens.

Antibodies, Monoclonal↗
PubMed1994

Inhibitory effect of aspirin on root resorption induced by mechanical injury of the soft periodontal tissues in rats.

The purpose of the present study was to study histologically and histometrically the inhibitory effect of aspirin on root resorption induced by mechanical injury of the periodontal soft tissues in rats. Resorption lacuna in the root surface of the molar in animals given both mechanical injury and aspirin administration contained fewer odontoclasts and was smaller in length and area than that in animals given only mechanical injury. The result of the present investigation indicated that the administration of aspirin might suppress root resorption induced by mechanical injury of the periodontal soft tissues.

Animals↗
PubMed1994

Effect of fluoride on root resorption caused by mechanical injuries of the periodontal soft tissues in rats.

The present study was carried out to investigate histologically and histometrically the effect of fluoride on root resorption induced by mechanical injuries of the periodontal soft tissues in rats. Resorption lacuna in the root surface of the molar in animals given both mechanical injuries and fluoride administration was significantly smaller in length and area than that in animals given only mechanical injuries. Moreover, resorption lacuna in the former animals contained fewer odontoclasts than that in the latter. The results of the present study might suggest that the administration of fluoride suppressed root resorption induced by mechanical injuries of the periodontal soft tissues.

Animals↗
PubMed1994

Chemical specificity of short-chain fatty acids in stimulating insulin and glucagon secretion in sheep.

The chemical specificity and structural requirements of short-chain fatty acids (SCFAs) in stimulating pancreatic endocrine responses was investigated in conscious sheep. Normal SCFAs with one to eight carbons were injected intravenously at seven doses of 39-2,500 mumol/kg body wt. The isomers or derivatives of SCFAs were administered at 625 mumol/kg body wt. Analysis of dose-response curves showed that n-butyric acid (4 carbons in the molecule) was most effective for both insulin and glucagon secretion among the normal SCFAs tested. In addition, one carboxylic group was absolutely required, since hormone secretion was significantly reduced or abolished with compounds in which the carboxylic element was replaced by other groups and with dicarboxylic acids. The form of the hydrocarbon chain (branched, cyclic, or benzoic ring) also affected hormone secretory activity. Most of the compounds that replaced hydrogen in the hydrocarbon chain by other groups at various positions reduced or abolished the hormone secretory effect obtained by n-butyric acid. In conclusion, a monocarboxylic acid with several numbers of hydrocarbons was required for insulin or glucagon secretion. These results suggest that the pancreatic endocrine system can recognize the chemical structure of SCFAs in detail and induce hormone secretion in sheep.

Animals↗
PubMed1994

Venous distensibility during pregnancy. Comparisons between normal pregnancy and preeclampsia.

Preeclampsia is associated with increased peripheral resistance. This study was performed to determine whether an increase of venous distensibility occurs as well in preeclampsia. We obtained venous distensibility by measuring the venous pressure-volume relation in the forearm with a water-filled plethysmograph. Twenty-one women with normal pregnancy, 12 women with severe preeclampsia, and 8 women with mild preeclampsia were studied during the third trimester and/or 6 weeks after the delivery. Ten nonpregnant normotensive women were also studied. Venous distensibility was greater (P < .01) in normal pregnant women and smaller (P < .01) in women with preeclampsia during pregnancy than postpartum. The magnitude of the decrease of venous distensibility correlated with the severity of preeclampsia. Venous distensibility was similar between normotensive nonpregnant women, women with normal pregnancy during the postpartum period, and women with preeclampsia during the postpartum period. Thus, venous distensibility increased during normal pregnancy. In preeclampsia, the decrease of venous distensibility occurred during pregnancy but was reversed postpartum. These results may suggest that a decrease of venous distensibility occurs during preeclampsia. These venous abnormalities may contribute to impaired control of hemodynamics in preeclampsia during pregnancy.

Adult↗
PubMed1994

Asymptomatic carotid lesions and silent cerebral infarction.

BACKGROUND AND PURPOSE: Few studies have investigated the relationships between asymptomatic carotid lesions and silent infarcts confirmed on magnetic resonance imaging. METHODS: A consecutive series of 117 subjects (average age, 62 +/- 9.4 years) who were free from neurological deficit but had at least one established risk factor for stroke were investigated by B-mode carotid ultrasonography and magnetic resonance imaging of the brain. Carotid lesions were evaluated by plaque score, maximum percent stenosis, and the existence of ulcerated lesions. The relations between the carotid lesions and the incidence, size, or localization of the brain lesions were investigated. RESULTS: The incidence of silent infarcts was 42% in all subjects and significantly increased with advancing age (P < .05). Most lesions were smaller than 1 cm in diameter and were usually localized in the subcortical white matter or the basal ganglia. The percentage of subjects with infarcts increased significantly as the plaque score increased (P < .05) or when subjects had high-grade stenosis (P < .05) or ulcerated lesions (P < .01). These relationships were also noted in each decade of age. A higher incidence of larger lesions (> 1 cm) was found in the brain hemisphere ipsilateral to the carotid lesion, particularly in subjects with high-grade stenosis or ulcerated lesions (P < .01). Multivariate analysis indicated significant correlations with silent infarcts for age, hypertension, and plaque score. CONCLUSIONS: Both the severity and characteristics of asymptomatic carotid lesions estimated by B-mode ultrasonography were closely related to the appearance of silent infarcts. These results demonstrate that noninvasive assessment of carotid lesions can be useful in predicting the existence of silent cerebral infarction even in patients free from neurological deficits.

Adult↗
PubMed1994

Paradoxical embolism as a cause of ischemic stroke of uncertain etiology. A transcranial Doppler sonographic study.

BACKGROUND AND PURPOSE: This study was designed to test the hypothesis that paradoxical embolization would be a cause of embolic strokes and transient ischemic attacks in patients with stroke of uncertain etiology in all age groups. METHODS: Thirty patients who had stroke of uncertain etiology were studied. They were divided into the following three groups: 13 patients with sudden onset (group A), 11 patients with subacute onset (group B), and 6 asymptomatic stroke patients (group C). Eleven patients with stroke of obvious etiology (group D) and 11 normal healthy volunteers (group E) were also studied as controls. In all patients transcranial Doppler sonography and contrast echocardiography were recorded simultaneously after intravenous injection of the contrast medium. Findings of positive patient foramen ovale in contrast echocardiography or "chirp" sounds in transcranial Doppler sonography were defined as positive for paradoxical contrast embolization. Radioisotope phlebography of the lower extremities and pulmonary scintigraphy, using technetium-99 macroaggregated albumin, were performed in all 17 patients who had positive findings of paradoxical contrast embolization and in 12 patients whose findings were negative. RESULTS: Positive findings of paradoxical contrast embolization were found in 17 subjects by transcranial Doppler sonography but in only 8 on contrast echocardiography. These positive findings were detected more frequently in group A (77%) than in groups B, D, and E (9%, 18%, and 9%, respectively) (P < .05). In group C, 4 of 6 patients (67%) had positive findings. There were positive findings on both phlebography and pulmonary scintigraphy only in 6 group A patients, with positive findings of paradoxical contrast embolization. CONCLUSIONS: Transcranial Doppler sonography is a sensitive detector of right-to-left shunts. Paradoxical cerebral embolization might be frequent in patients with stroke of unknown etiology, especially when the stroke is of sudden onset.

Adult↗
PubMed1994

Effects of ascorbic acid on iproniazid-induced hepatitis in phenobarbital-treated rats.

The effects of ascorbic acid (AA) on hepatic injury induced by iproniazid (IPN) in phenobarbital-treated rats were investigated by the evaluation of hepatic function using the clearance of aminopyrine (AM). Either IPN or isopropylhydrazine (IP-Hy), a potent toxic metabolite of IPN, were administered as a pretreatment to rats with or without AA. After i.v. injection of AM, the blood concentration of AM was determined by capillary gas chromatography by isotope dilution analysis using deuterium-labeled AM (AM-d9) as the internal standard. The kinetic parameters of AM, Vd, kel and total body clearance, were estimated from the time course of blood concentration. Pretreatment with IPN with AA led to a marked increase in the kel and in the clearance compared with pretreatment using IPN alone. A significant increase in the kel and the clearance was also found in the case of combined pretreatment using IP-Hy with AA. The effects of AA on the hepatic injury induced by IPN were studied according to its histological aspects. In the specimens obtained following the administration of IPN or IP-Hy with AA, the degree of cell necrosis was remarkably lowed both quantitatively and qualitatively. The present results clearly demonstrate that AA was effective in reducing IPN-induced hepatitis.

Alanine Transaminase↗
PubMed1994

Isotopic fractionation of isopropylantipyrine and its deuterated analogues by capillary gas chromatography.

Isotopic fractionation of isopropylantipyrine (IPA) and its deuterated analogues was examined by gas chromatography (GC) using capillary column. The separation of IPA and seven kinds of deuterated IPAs were proportional to the number of labeled deuterium atoms and inversely to the temperature of the column oven. The resolution coefficient between IPA and IPA-3-C2H3-4-(C2H3)2 (IPA-2H-7) was 1.46 at 200 degrees C for column temperature. The present isotopic fractionation procedure was applied to the isotope dilution analysis of IPA. Measurement of the sample prepared by the addition of a known amount of IPA and IPA-2H-7 to the control plasma of rabbit allowed observation of a linear relationship between peak area ratio and added amount ratio. The correlation coefficient obtained by regression analysis was 1.000. The present method was also applied to determine the plasma level of IPA in rabbit after oral administration.

Animals↗
PubMed1994

Study of the effect of a Chinese medical preparation, hokoei-to, on the rat ovary.

Female rats were given Hokoei-to orally to investigate its effects on hormones. Progesterone and estradiol levels fell markedly in ovariectomized young rats. Administration of Hokoei-to for 25 d produced increased levels of hormones in these rats. A similar effect was found in parous rats, demonstrating replacement of the lost female hormones after Hokoei-to administration.

Administration, Oral↗
PubMed1994

Aminopeptidase P, capable of hydrolyzing oligoproline, from bovine brain.

An aminopeptidase P, capable of hydrolyzing oligoproline, was isolated from the homogenate of bovine brain. The molecular mass of the enzyme was 140 kDa by gel filtration. The enzyme was activated by Mn2+ and inhibited by o-phenanthroline. The enzyme hydrolyzed substrates such as Pro-Pro-Pro-Pro, Pro-Pro-Pro, and Pro-Pro to proline, and cleaved N-terminal amino acids from peptides containing penultimate prolines such as bradykinin and neuropeptide Y.

Amino Acid Sequence↗
PubMed1994

Respiratory muscle strength and hemodynamics in chronic heart failure.

To examine whether respiratory muscle weakness is associated with cardiac function and/or exercise capacity in chronic heart failure (CHF), 23 patients with CHF were evaluated with respiratory muscle strength, pulmonary function tests, cardiac catheterization, and exercise test. The subjects were divided into three groups on their New York Heart Association (NYHA) functional class. Group A consisted of 13 patients with NYHA functional classification class 3 or 4, group B consisted of 10 patients with NYHA classification class 2, and group C consisted of 15 age-matched normal controls. Respiratory muscle strength was assessed with maximal static inspiratory mouth pressure at residual volume level and expiratory mouth pressure at total lung capacity level (PImax, PEmax, respectively). Pulmonary functions in patients with CHF showed almost normal. PImax in group A was significantly less than that in group B or C, although PImax in group B was not significantly different from that in group C. In the patients with CHF, PImax correlated positively with cardiac index and maximal oxygen consumption (r = 0.460 and r = 0.503, p < 0.05, respectively). These findings suggest that inspiratory muscle strength, which was impaired in patients with severe CHF, may be dependent on cardiac function and may be one of the limiting factors on impaired exercise capacity in the patients with CHF.

Aged↗