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Biomedical subjects

I S Watanabe

Publications and source records attributed to I S Watanabe.

At least 37 records · Page 2Linked to original sources
PubMed1985

Effects of tobacco and non-tobacco cigarette smoking on endothelium and platelets.

Endothelial damage and platelet activation may mediate increased cardiovascular morbidity and mortality in tobacco cigarette smokers. Our study was designed to determine whether acute effects of tobacco smoking on endothelium and platelets could be avoided by the substitution of non-tobacco cigarettes. Twenty healthy nonsmokers smoked two tobacco cigarettes in 20 minutes and on another occasion (separated by 1 week) smoked two cigarettes made from wheat, cocoa, and citrus plants. Mean endothelial cell counts from venous blood before and after smoking tobacco cigarettes were 2.3 and 4.8 and before and after smoking non-tobacco cigarettes counts were 2.5 and 3.0. Mean platelet aggregate ratios before and after smoking tobacco cigarettes were 0.80 and 0.65 and before and after smoking non-tobacco cigarettes they were 0.81 and 0.78. Much greater effects of tobacco smoking on endothelial cell counts and platelet aggregate ratios suggest the possibility that non-tobacco cigarette smoking may be less harmful to the cardiovascular system than is tobacco cigarette smoking.

Adult↗
PubMed1985

Ototoxicity of intraventricularly administered gentamicin in adult rabbits.

To determine whether daily intraventricular injection of gentamicin sulfate is ototoxic, adult male rabbits were given 0.2 ml of saline (group 1; n = 8) or 0.25 mg/kg of gentamicin sulfate in 0.2 ml of saline (group 2; n = 7) by intraventricular infusion once a day for 21 d. All rabbits were also given intramuscular gentamicin sulfate, 2 mg/kg, twice daily. Before and after antibiotic treatment, brainstem auditory evoked responses (BAERs) were recorded. During the experimental period, neurologic examinations were performed on all rabbits. After treatment, the animals were euthanized; brain tissue and cochleas were then removed for histopathologic examination. The ratios of neurologic abnormalities observed in group 1 and 2 animals, respectively, were 0/8 and 5/7; of abnormal BAERs, 0/8 and 5/7; of abnormal brain morphology, 2/5 and 6/6; and of abnormal cochlear morphology, 0/6 and 7/7. The electrophysiologic evidence of auditory deficit and the structural evidence of ototoxic insult are significantly associated (p less than or equal to 0.006) with intraventricularly administered gentamicin sulfate. These data suggest that intraventricular gentamicin should be used with caution.

Animals↗
PubMed1984

Low energy levels in thiamine-deficient encephalopathy.

Pyrithiamine-induced acute thiamine-deficient encephalopathy was produced in adult male Wistar rats. Twenty-four hours before the onset of neurological signs the brain showed no morphological abnormalities. Encephalopathic rats had symmetrical lesions of edematous necrosis localized in the thalamus, mammillary body, and pontine tegmentum. Biochemically, encephalopathic rats had brain thiamine levels less than 20% of controls. For the assay of the concentrations of adenosine triphosphate (ATP) and phosphocreatine, the brains were fixed using 5 KW microwave irradiation and were divided into four parts: cerebral cortex, diencephalon, lower brainstem, and cerebellum. In the lower brainstem of the encephalopathic rats ATP concentrations were 89.5% of normal controls. Phosphocreatine levels were lowered to 70% of controls in the diencephalon and to 75% in the lower brainstem. Total high energy phosphate levels were decreased to 89% of controls in the diencephalon and 91% in the lower brainstem before the onset of neurological signs and to 76% and 79%, respectively, after the onset. In the cerebral cortex and cerebellum high energy phosphates were not significantly reduced. Lower high energy phosphate levels and the distribution of edematous lesions were coincident in the brain. These findings suggest that a low energy state is closely related to the formation of edematous lesions in thiamine-deficient encephalopathy.

Animals↗
PubMed1983

Effect of glycerol on peripheral nerve: an experimental study.

Håkanson's method of treatment of trigeminal neuralgia by injecting glycerol into the trigeminal cistern is being used in a few clinical centers with encouraging results. We undertook this experimental study utilizing a rat sciatic nerve model to elucidate the mode of action of glycerol. Fifty-six rats were divided into three groups. The topical application of pure glycerol on the sciatic nerve was used in Group I. The intraneural injection of glycerol was used in Group II. The effect of graded concentrations of glycerol was studied in Group III. Physiological saline was the control in Groups I and II. The animals were killed at the end of either 1 or 3 1/2 weeks after the application of glycerol, and the sciatic nerves were examined with light and electron microscopy. Our results show that myelin disintegration and axonolysis occur with glycerol application. Myelinated and unmyelinated fibers are affected at random, although the most striking histological changes were seen in the myelinated fibers.

Animals↗
PubMed1978

About the existence and endings of nerve fibres in the Cebus apella monkey's upper lip.

In the present research, fibres and nerve endings of upper lip of the Cebus apella monkey have been studied. Upper lip of 8 Cebus apella were analysed. The pieces were prepared according to the technic of Castro's silver impregnation and submitted to serial sections 8 micra thick. Our results permit to conclude that the Cebus apella monkey's upper lip has a great number of free nerve endings, between connective and epithelial layers in the mucosa and in the skin. The aspects of nerve fibres and their free and organized endings, like Meissner's corpuscles, in the upper lip mucosa of the monkey, allow comparison of similarity with those of man. The nerve endings in the lip skin of the Cebus monkey are also abundant, characterizing the hair follicles and sebaceous glands innervation and the free nerve endings encountered in the connective tissue as well as in the sub-epithelial layer.

Animals↗
PubMed1978

[Teaching of anatomy in school of dentistry: evaluation of achievement (author's transl)].

An experience of application didactics to the teaching of Anatomy in Dentistry's School was performed. The general part of Anatomy--Systems of the Human Body--was given and evaluated according to the subjects aims of this paper. It were also presented the experience characteristics and the degree of student's achievement in the differents groups was statistically analysed.

Anatomy↗
PubMed1977

Split-line patterns of the mandible following masseterectomy in adult and growing monkeys.

Architectural changes of the mandibular ramus following masseterectomy were analyzed by means of the split-line technique in both adult and growing monkeys. The right masseter muscle was resected in ten tufted capuchin monkeys (Cebus apella) and they were sacrificed following a 12-month period. Along with modifications in the shape of the mandible, the masseterectomy induced structural changes as revealed by alterations in the split-line patterns. These changes were much more evident in the adult animals. In growing monkeys, intrinsic forces determine an architecture of mandibular growth, represented by the direction of the splits. This is not influenced by the lack of mechanical factors like muscle action. Conversely, the final fibrous architecture of the bone in the adult monkey may be modified by extrinsic mechanical factors.

Age Factors↗
PubMed1977

Innervation of the palatine mucous membrane in the Cebus apella monkey.

A histological study was conducted on the innervation of the Cebus apella palatine mucosa. Ten monkeys were used for the present study. After perfusion with 10% formalin, the whole hard palate mucosa was removed in one piece and made into histological sections according to De Castro's method for silver impregnation. We concluded that the nerve fibers form free endings and organized corpuscles, like Meissner corpuscles. Free nerve endings are numerous in the hard palate mucosa and they show a great variety in form and size.

Animals↗
PubMed1977

Neurohistological observations on the tongue of the tufted capuchin, Cebus apella Linnaeus, 1758.

Neurohistological observations of the tongues of the adult monkeys Cebus apella are described. It was noted that the Cebus tongue presents few vallate papilae situated mainly in the posterior and lateral parts; fungi and filiforms are spread all over the dorsal surface. Histologically there was evidence that numerous nerve fibres of variable size come from the deep layers of the tongue to the surface structure. In many regions they constitute plexuses, other cross the muscular and glandular layers, going to the epithelial layer of the tongue's mucosa. The vallate and fungiform papillae are supplied with abundant nerve fibres which terminate free and are furnished with many taste buds. The epithelium and surrounding connective tissue is innervated by the fibres with free or ramified endings. The muscular layer shows muscle fibres distributed in all directions and the presence of motor end plates and nerve fibres is evident.

Animals↗
PubMed1977

[The clivus-sphenoidale angle in children (postnatal flexion of the cranial base)].

The clivus-sphenoidale angle of Landzert expresses the flexion of the cranial base in sagittal direction. In previous studies the same authors verified that the clivus-sphenoidale does not change between the 4th and 9th month of fetal life, with an average value of 127.58 degrees, and that in the adult the angle measures 113.95 degrees. To analyse the variations of the opening of this angle in an age span intermediary to those studied before, 89 human skulls were used belonging to both sexes and varying in age from 2 months extrauterine life to 8 years. The angle was traced and measured upon lateral X-rays taken from all skulls. The distribution of average values according to age is found in tables 1 and 2. For statistical evaluation of data, regression analysis and comparison of averages were used. At hand of the results, it is possible to conclude that: 1) there is a significant reduction of the clivus-sphenoidale angle after birth, that is, from 2 months extrauterine life to 18 months. 2) There is no difference in the average values of the angle between 2 and 8 years of age. 3) Growth of the brain and upright posture seem to be the factors most responsible for the post-natal flexion of the cranial base. 4) The angles show great individual differences in all age groups studied.

Age Factors↗
PubMed1977

Morphologic analysis of the "spina mentalis" in adult mandibles of Brazilian whites and negroes.

This study was carried out to verify the morphology of the spina mentalis. We observed 275 human adult mandibles of both sexes and ethnic groups. An analysis of the results allows the following conclusions: 1. The spina mentalis exists in 90.04% +/- 1.8 of the mandibles of Whites and Negroes; 2. The typical form with four tubercles, as described by some authors, is rarely found; 3. In most cases it characterized by the presence of two upper tubercles (27.27% +/- 7.2); two superior tubercles and one inferior (24.72% +/- 6.7), and one elongated median tubercle (24.0% +/- 6.6); 4. The forms and volumes of the tubercles are very irregular and seem not to depend on age, sex or ethnic group; 5. The spina was absent in 9.8% +/- 3.2 of the cases, especially in mandibles of White teethless individuals; 6. An hypertrophic spina mentalis, generally formed at the expenses of the upper tubercle, is observed in only 1.45% +/- 0.5 of the cases.

Black People↗
PubMed1976

Neurohistologic observations of the Cebus apella monkeys soft palate mucosa.

A neurohistological observation was done in the solf palate mucosa of the Cebus apella monkey. Six mucosa were employed and were removed after perfusion of each animal, with 10% formalin solution, through the external carotid artery of the right side. The mucosa was removed together with the muscular layer and salivary glands. The histologic analysis was performed and therefore the pieces were prepared by the "De Castro" technic of silver impregnation. The material was embedded in the vertical sense to allow frontal sections with the thickness of 8 micra. Our findings allow the following conclusions: a) the mucosa innervation of the soft palate is essencially done by the branches of the lesser palatine nerve; b) the free nerve endings of the soft palate mucosa have a great variation in the form and size and are abundant; c) the superficial fibres are related to the general sensibility and the deepest are directly connected to the innervation of the salivary glands.

Animals↗
PubMed1975

Anatomical data on the intracranial venous drainage of the tufted capuchin, Cebus apella Linnaeus, 1758.

The venous channels responsible for the intracranial drainage were dissected in a series of 25 male and female adult tufted or brown capuchin monkeys (Cebus apella). It was found that Cebus have a venous arrangement fundamentally the same as in man, differing only in that: 1. the monkey has no inferior sagittal sinus, spenoparietal sinus, and emissary parietal and condylar veins; 2. the occipital sinus is not in connection with other sinuses; 3. there are a spenopetrosal sinus, a petrosquamous sinus, and an unpaired inferior cerebellar vein; 4. besides the internal jugular vein, there is additional intracranial drainage through the petrosquamous sinus and the postglenoid vein; 5. the superficial middle cerebral vein opens into the petrosquamous sinus; 6. the lingual and facial veins are not tributaries of the internal jugular vein; 7. there is a bilateral uniform division of the superior sagittal sinus at the confluence of the sinuses to drain equally into both transverse sinuses; 8. the vascular pattern appears to be quite stable; anatomical variations appear to be few and unimportant.

Animals↗