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Biomedical subjects

C Watanabe

Publications and source records attributed to C Watanabe.

At least 145 records · Page 8Linked to original sources
PubMed1991

A change in the spontaneous release of endogenous acetylcholine from rat striatal slices after repeated injection of haloperidol.

The spontaneous and 50 mM K(+)-stimulated release of endogenous acetylcholine (ACh) from rat striatal slices was measured to investigate an adaptive change of striatal ACh after a withdrawal period for 24 h from chronic treatment of the rat with haloperidol. The haloperidol injections (2.5 mg/kg/day) for a period of 3, 7 or 14 days all reduced the spontaneous release of ACh significantly by 20-50% without changing tissue levels of ACh. On the contrary, these treatments produced a very small (by about 10%) but significant increase in K(+)-stimulated release except for the treatment of 7 days. These results suggest that the spontaneous ACh release is under the control of a dopaminergic mechanism, which might be different from the mechanism controlling the evoked release of ACh and emerges following withdrawal from chronic haloperidol treatment.

Acetylcholine↗
PubMed1991

Gastric mucosa in female patients with fundic glandular polyps.

To evaluate the characteristics of the gastric mucosa in women with fundic glandular polyps, we examined gastric acid secretion, fasting serum levels of pepsinogen I and gastrin, and gastric histology in 11 female patients with fundic polyps, and compared the results with 30 female controls without endoscopic abnormalities and 50 female patients with gastric foveolar hyperplastic polyps. No significant difference was found in gastric and secretion and fasting serum levels of pepsinogen I and gastrin between the patients with fundic glandular polyps and the control subjects. Histological examination showed that atrophic gastritis was generally not found in the patients with fundic glandular polyps. In contrast, gastric acid secretion and fasting serum levels of pepsinogen I were significantly lower and serum gastrin levels were significantly higher in the patients with foveolar hyperplastic polyps than in the other two groups. Also, patients with foveolar hyperplastic polyps had a higher prevalence and further advanced atrophic gastritis in the fundus than did the other two groups. Our investigations demonstrated that fundic glandular polyps arise from gastric mucosa without atrophic gastritis, whereas foveolar hyperplastic polyps develop from mucosa affected by atrophic gastritis, especially type A gastritis.

Female↗
PubMed1991

Lack of correlation between P pulmonale and right atrial overload in chronic obstructive airways disease.

The correlation between P pulmonale and right atrial overload in chronic lung disease was studied. Right atrial pressure, pulmonary artery pressure, and cardiac output were measured with a Swan-Ganz catheter in nine patients with chronic lung disease and P pulmonale on the electrocardiogram (P wave amplitude of greater than or equal to 2.5 mm (0.25 mV) in leads II, III, and a VF. The results were compared with those in six patients with an atrial septal defect (left to right shunt greater than or equal to 50%) and six patients with pulmonary hypertension (mean pressure greater than or equal to 30 mm Hg without left sided heart disease). Right atrial volume and wall thickness were measured in 10 cases of P pulmonale among 1000 necropsy cases and compared with 141 normal hearts from the same series. The patients with P pulmonale did not show a significant increase in right atrial or pulmonary artery pressures. None of the patients with an atrial septal defect or pulmonary hypertension had P pulmonale on the electrocardiogram. In the necropsy cases of P pulmonale mean (1 SD) in right atrial volume (32 (12) ml) and wall thickness (1.5 (0.7) mm) were not significantly increased (40 (14) ml and 1.4 (0.5) mm in the normal hearts). There was a significant inverse relation between the presence of P pulmonale and the cardiothoracic ratio. In all the patients with P pulmonale chest x ray showed a low cardiothoracic ratio, a considerably depressed diaphragm, and a pendulous heart. This study showed no correlation between P pulmonale and right atrial overload in chronic lung disease. A more vertical anatomical position of the heart, particularly of the right atrium, seems to be the major factor responsible for generation of P pulmonale in chronic airways disease.

Aged↗
PubMed1991

[Systolic anterior motion of the anterior mitral leaflet and/or the chordae tendinae in the elderly].

Systolic anterior motion of the anterior mitral leaflet and asymmetric septal hypertrophy (ASH) are characteristic features of hypertrophic obstructive cardiomyopathy (HOCM) on an echocardiogram. Among 9,670 patients over 60 years old examined by echocardiography from January, 1984 to October, 1990, 55 patients showed systolic anterior motion of the anterior mitral leaflet and/or the chordae tendinae (SAM). We investigated clinical features and morphological features of the left ventricle on an echocardiogram in the 55 patients with SAM. They were classified into three groups according to the degree of SAM. Thirty eight cases (group I) had no mitral and/or chordal-septal contact, 10 (group II) had brief contact (less than 30% on the echocardiographic systole) and 7 (group III) had prolonged contact (greater than or equal to 30%). Ages ranged from 60 to 99 with a mean age of 78.2 years. There were 19 males and 36 females and there was a predominance of females in each group. Thirty five cases had hypertension and 34 left ventricular hypertrophy on electrocardiograms. One case of group I, 3 of group II and 7 of group III had a clinical diagnosis of HOCM. In comparison with each group, the incidence of LVH (SV1 + RV5 greater than or equal to 35 mm) was 52% in group I, 90% in group II and 83% in group III and that of LVH (SV1 + RV5 greater than or equal to 70 mm) was 29%, 20% and 67%, respectively. On echocardiographic examination, the diastolic descent rate of the anterior mitral leaflet in the 3 groups was 36.1 +/- 13.1 mm/sec, 19.4 +/- 13.1 mm/sec and 10.7 +/- 11.8 mm/sec (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Influence of water on the transverse strength of posterior composite resins.

In an attempt to evaluate the influence of water on the mechanical properties of composite resin, the transverse strengths of 15 commercially available composites were determined in water at 37 degrees C and compared with the strength measured in air after storage in water for periods of 1 day to 3 months. Some of the composites, including two which contained a blend filler, showed remarkable reduction of transverse strength when measured in air, according to the procedures specified in ISO 4049, in comparison with transverse strength measured in water. The change of water content in the material can predominantly affect the mechanical behavior of composite resin.

Composite Resins↗
PubMed1991

[Morphological observation of the mitral annulus fibrosus (II)].

In 1986, Hutchins observed a high incidence of the disjunction of the mitral annulus fibrosus in mitral valve prolapse syndrome. However, we could not prove his view in our previous study using one section in each case. In this study, the types of mitral annulus fibrosus were analyzed in plural sections. Autopsy hearts of nine aged cases were used for examination of the mitral annulus fibrosus in five to eight longitudinal sections from the posterolateral wall. The types of the mitral annulus fibrosus were classified as; Type A (the mitral valve attaches to the left ventricle), Type B (the valve attaches to the left atrium), Type C (the atrialis layer of the valve continues to the left atrium, while the fibrosa layer continues to the left ventricle), and type D (mitral annulus calcification). A1-3 and B1-3 are subtypes. In the nine cases there were no consistent patterns in type distributions. All sections showed Type A1 (Case 2), Type A1 to A3 (Case 5), and Type B1 to B3 (Case 8). In other cases, a combination of Type A and B (Case 4, 6, 7, 9), and inclusion of Type C (Case 1) and Type D (Case 3) were found. The location of the middle scallop of the posterior mitral leaflet corresponded to the section of the previous study. Among three cases of Type A in the middle scallop, two showed Type A in every section. Among five cases of Type B in the middle scallop, only one case showed Type B in every section. Other four cases showed various combinations with the other types. A case of Type D in the middle scallop showed also Type B and Type C. The conclusion of this study was that in 1/3 of the cases, the type of the mitral annulus fibrosus was consistent, but in the other 2/3 they were not consistent. In other words, one section is not necessarily representative of the morphology of the mitral annulus fibrosus in each case.

Aged↗
PubMed1990

Toxicity modification of sodium selenite by a brief exposure to heat or cold in mice.

The effect of a brief exposure to heat/cold on the subsequent development of toxicity of sodium selenite (SS) was evaluated in male ICR mice. Mice were exposed to one of three ambient temperatures (Ta; approx. 8 degrees, 22 degrees and 33 degrees C). One and a half hours after the beginning of the exposure, they were injected with 45 mumol/kg of SS subcutaneously. The exposure was terminated 3 h after injection and the mice were returned to Ta of 22 degrees C. Heat-induced enhancement of toxicity was recognized in some plasma enzyme activities 3 days after injection and in the suppression of body weight for up to 3 weeks. On the other hand, cold exposure alleviated SS toxicity in terms of these indices. Thus, the Ta during this short period was recognized to be important in determining subsequent development of SS toxicity. At the end of the thermal exposure, heat increased renal concentration of the injected Se. On the other hand, in the liver and the other organs examined, the highest Se concentration was found in the cold-exposed group, followed by the control (room temperature) and the heat-exposed. The relation between the modification of toxicity and the altered distribution was not clear. Neither glutathione level in the liver nor that in the kidney at the time of SS injection could explain the observed modification of the toxicity.

Animals↗
PubMed1990

Modification by nickel of instrumental thermoregulatory behavior in rats.

The effects of NiCl2 on the colonic temperature and thermoregulatory behavior (TRB) of rats were examined. TRB was evaluated in an instrumental (operant) setting in which rats were required to press a level to obtain convectional heat (SEEK) or to avoid heat (ESCAPE). Orthogonal polynomial regression was used to describe the response patterns in both the SEEK and ESCAPE situations. Two milligrams per kilogram of Ni (ip) caused rapid, transient hypothermia at an ambient temperature of 21 degrees C. When given access to heat reinforcement, rats responded for heat at a lower rate immediately after 2 or 5 mg/kg of Ni (up to 5-15 min) than after saline. Subsequently, response rates rose 30 min or more after Ni injection. A converse pattern was found with the heat escape situation. These observations, confirmed by two contrasting procedures, indicate that the changes were thermoregulatory in nature and cannot be explained by nonspecific suppressive or excitatory effects of Ni. They further suggest that Ni-induced hypothermia results from an altered body temperature set point. The subsequent reversal in behavior probably arises from a direct action of Ni on autonomic effector mechanisms. The origin and biological significance of these findings require further investigation. Physical requirements and response topography are discussed as critical variables in the interpretation of experiments requiring similar responses under different ambient temperatures.

Animals↗
PubMed1990

Transient hypothermia and hyperphagia induced by selenium and tellurium compounds in mice.

The effects of sublethal doses of selenite, selenate, selenocystine (Se-Cys) and selenomethionine (Se-Met) as well as of tellurite on body temperature and feeding behavior were examined in male ICR mice. Ten or 30 mumol/kg of chemicals were injected subcutaneously and body temperature was measured up to 4 h. In a separate experiment, the gastric content was weighted 4 h after injection. All chemicals except Se-Met induced both hypothermia and hyperphagia, suggesting that: (a) these two effects are related to each other; (b) among the chemicals tested, Se-Cys appears to be the most potent hypothermia inducer; (c) Se-Met is unique in that it has neither effect.

Animals↗
PubMed1990

Possible role of cementoblasts in the resorbant organ of human deciduous teeth during root resorption.

Human deciduous teeth undergoing physiologic root resorption were extracted and fixed with a mixture of formaldehyde and glutaraldehyde and processed for scanning (SEM) and transmission (TEM) electron microscopy, and for acid (ACPase) and alkaline phosphatase (ALPase) cytochemistry. The resorbant organ, rich in odontoclasts, cementoblasts, fibroblasts, and macrophages, formed prominent resorption lacunae in root dentin. SEM observations of resorption lacunae treated with trypsin solution showed islands of newly-formed cementum matrix in part of the resorbing dentin surfaces. Such cementum consisted of bundles of densely-arranged collagen fibrils and, in part, contained forming cementocytic lacunae and canaliculi. Active cementoblasts adjacent to odontoclasts on resorbing dentin surfaces showed cuboidal outlines and were characterized by the presence of numerous cisterns of rough endoplasmic reticulum, well-developed Golgi complexes, secretion granules, and many mitochondria. They sometimes formed a thin layer of cementoid and/or cementum matrix upon the resorbing dentin surface. These cementoblasts had ACPase-positive lysosomes in the cell bodies and exhibited intense ALPase activity along the plasma membranes of whole cell surfaces. These results suggest that, during root resorption, 1) active cementoblasts are present adjacent to active odontoclasts and 2) these cementoblasts are involved in remodeling the resorbing dentin surfaces.

Acid Phosphatase↗
PubMed1990

Cellular roles in physiological root resorption of deciduous teeth in the cat.

This study has attempted to assess the importance of mesenchymal cells, fibroblasts, cementoblasts, and mononuclear phagocytes (i.e., macrophages) in physiological root resorption of feline deciduous teeth. Deciduous incisors of three- to six-month-old kittens undergoing root resorption were investigated by means of electron microscopy. In an early phase of root resorption, the resorption organ consisted of many fibroblasts and relatively few macrophages and odontoclasts, the last with a wide, clear zone and narrow, immature, ruffled border. In the active phase of root resorption, the resorption organ contained many odontoclasts with a well-developed ruffled border and a reduced clear zone, cementoblasts, fibroblasts, macrophages, neutrophils, and many blood vessels. Cementoblasts were present usually on the resorbing dentin surface adjacent to odontoclasts and, in many cases, these cells communicated with each other via gap junctions. Cementoblasts frequently extended broad cell processes with secretion granules and with phagosomes containing collagen fibrils into the dentinal tubules exposed to resorption lacunae. Some macrophages exhibiting a clear zone-like structure also appeared on resorbing dentin surfaces. In the resting phase of root resorption, the dentin surface was covered mostly with cementoblasts resembling bone lining cells. There was an occasional macrophage, but no odontoclasts were observed during this phase. During removal of the periodontal ligament concomitant with root resorption, many fibroblasts phagocytosed mature collagen fibrils, as well as amorphous fluffy material. These results suggest that these mesenchymal cells, as well as odontoclasts, are essential for the cellular removal of dental hard and soft tissues during shedding of feline deciduous teeth.

Animals↗
PubMed1990

[A clinical study of hypertrophic obstructive cardiomyopathy in the elderly].

Seven elderly patients with hypertrophic obstructive cardiomyopathy (HOCM), who had the three following characteristics on echocardiograms 1) extremely thickened septum, 2) systolic anterior motion of the mitral valve, 3) mid systolic semi-closure of the aortic valve, were clinically evaluated. Ages ranged from 73 to 86 years old (average 78.9% yr.) and all were women. None had not a family history of hypertrophic cardiomyopathy but they had mild hypertension. Six patients showed a significant high voltage on the ST-segment and T-wave abnormalities ("strain" pattern). The left ventricular posterior wall as well as the septum was thickened in 5 and the remaining 2 showed asymmetrical septal hypertrophy (ASH) on echocardiograms. The left ventricular cavity was narrowed due to left ventricular hypertrophy and the shape of the left ventricular cavity was ovoid in all patients. The aorto-septal angles in these 7 patients were 80 degrees to 120 degrees. In addition, proximal septal bulge in all and anterior displacement of the mitral posterior leaflet due to the mitral ring calcification (MRC) in some patients contributed to the narrowing of the left ventricular outflow tract, and the mitral valve was pulled up toward the septum because of the good left ventricular systolic function (ejection fraction: 70 to 94% by echocardiography) and blood was ejected at a high velocity through a narrowed outflow tract (Venturi effect). Pressure gradients in the left ventricular outflow tract was 38 to 146 mmHg in 5 examined by cardiac catheterization. Biopsy specimens were obtained from 2 patients, showing hypertrophic myocytes (diameter: 20 to 30 micron) in 2 and mild disarray in 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Morphological observation of the mitral annulus fibrosus in patients with mitral valve prolapse].

Sixteen cases of mitral valve prolapse (MVP) with mitral regurgitation (MR) in the aged (mainly in their eighth and ninth decades) with both clinical and pathological evidences were investigated. One hundred autopsy cases served as the control. The longitudinally-sectioned mitral annulus fibrosus was pathologically studied in all with special reference to the atrium-valve disjunction reported by Hutchins. Morphologically, the mitral annulus fibrosus was classified either as type A (the mitral valve attaches to the left ventricle), type B (the mitral valve attaches to the left atrium: Hutchins' disjunction), type C (the atrialis continues to the left atrium and the fibrosa to the left ventricle), or type D (mitral annulus calcification). Type B was observed in only 31% of the MVP cases, whereas it was seen in 43% of the control cases. It was concluded that Hutchins' observation could not be regarded as the characteristic pathological finding of MVP.

Aged↗
PubMed1989

A case of benign cementoblastoma.

A rare case of benign cementoblastoma is reported. Active cementoblasts adding cementoid tissue were observed histologically by means of specific staining for unmineralized matrix of hard tissue. A polarizing microscope and an x-ray diffractometer were used to clarify the cementum-like tissue of benign cementoblastoma. The collagen bundles of tumor tissue showed irregular and random arrangements under polarized light. The qualitative analysis revealed that the mineralized component was composed of low-crystalline hydroxylapatite.

Adolescent↗
PubMed1989

Cytodifferentiation and degeneration of odontoclasts in physiologic root resorption of kitten deciduous teeth.

To investigate the cytodifferentiation and degeneration of odontoclasts in physiologic root resorption, we studied deciduous incisors undergoing resorption in 6-month-old kittens by electron microscopy of ultrathin sections. The endogenous peroxidase activity within the cells was also examined by incubating the tissue slices in diaminobenzidine-H2O2 medium. The resorbing tissues, consisting of multinucleated giant cells, macrophages, granular leukocytes, fibroblasts and many blood vessels, were observed at the resorbing surface of the root dentine. Macrophages and granular leukocytes exhibited endogenous peroxidase activity, but mononuclear and multinucleated preodontoclasts and multinucleated odontoclasts did not. These preodontoclasts contained abundant mitochondria, a moderate amount of rough endoplasmic reticulum, stacks of Golgi membranes, lysosomes and numerous polyribosomes scattered throughout the cytoplasm. Many cellular processes extended from their cell surfaces by which the preodontoclasts appeared to fuse to one another during their multinucleation. Concomitant with the multinucleation process, the preodontoclasts developed numerous pale vacuoles throughout the cytoplasm. These vacuoles seemed to arise from some smooth endoplasmic reticula, perhaps representing Golgi-endoplasmic reticulum-lysosome, and the Golgi saccules. However, the preodontoclasts did not yet form a ruffled border and clear zones. When these preodontoclasts came into direct contact with resorbing dentine surfaces, they began to form the clear zones against dentine surfaces. Characteristically, numerous pale vacuoles were accumulated in the cytoplasm adjacent to the clear zone, then they penetrated into the cytoplasm of the clear zone, and with this, ruffles of the plasma membranes appeared. Through a further movement of more pale vacuoles towards the ruffled plasma membranes, the odontoclasts developed typical ruffled borders against the resorbing dentine surfaces. At this differential phase, little pale vacuoles appeared in the Golgi area, but the cisterns of the Golgi apparatus themselves reached their greatest extent during cellular differentiation. Fully differentiated odontoclasts frequently extended long broad cellular processes into the dentinal tubules exposed to the resorption lacunae. Although some odontoclastic processes penetrating the dentinal tubules contained vacuoles and lysosomal structures, most processes lacked any cytoplasmic organelles, and their cytoplasm resembled that of the clear zone. But these processes never exhibited ruffled-border-like structures.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

A clinicopathologic study of the accessory bypass tracts in six cases of Wolff-Parkinson-White syndrome.

A clinical and histologic correlation study was conducted to examine the accessory bypass tracts in 6 cases of Wolff-Parkinson-White syndrome. (1) Types A, B (Rosenbaum) and C (Ueda) were found in 2 cases each. From the polarity of the delta waves, the site of the bypass tract was assumed to be in the left posterior and left lateral free wall in type A, the right lateral and right posterior paraseptal regions in type B and in the right posterior paraseptal and right anterior paraseptal areas in type C. (2) In 6 cases 19 bypass tracts were found, consisting of 18 Kent bundles and 1 Mahaim fiber, from a total of 146,400 serial sections. The site of the bypass tract was the left lateral and left posterior walls in 2 type A cases, and the right lateral and right posterior walls in 2 type B cases, with good correspondence to our assumption. In both type C cases it was biventricular, composed of left posterior paraseptal and right lateral regions with an additional Mahaim fiber in 1 case. (3) A total of 46 cases of WPW syndrome were collected from the literature and the present paper; they consisted of 16 cases of type A, 20 of type B, 4 of type A + B and 6 of type C. Seventy % of type A cases showed a bypass tract in the left heart, and 64% of type B in the right heart. In 6 cases of type C, the bypass tract was found in various sites and in various combinations, requiring further investigation.

Adult↗