Search PubMed⌕ Search

Biomedical subjects

J Suzuki

Publications and source records attributed to J Suzuki.

At least 523 records · Page 29Linked to original sources
PubMed1989

[Venous hum and innominate vein flow velocity in chronic anemia: a pulsed Doppler echocardiographic study].

To assess the hemodynamic correlates of the cervical venous hum in patients with chronic anemia, 14 patients (mean age; 49 years, mean hemoglobin (Hb); 7.3 g/dl) and 14 control subjects (mean age; 50 years, mean Hb; 14 g/dl) without cardiac disease were studied by auscultation, phonocardiography and Doppler echocardiography in two positions (supine and sitting). Venous hum was detected in the sitting position in 11 of the 14 anemic patients whose Hb was less than 9 g/dl, and in six anemic patients in the supine position, while venous hum was absent in the control subjects in both positions. Pulsed Doppler echocardiography with the transducer in the supraclavicular fossa revealed significantly (p less than 0.01) higher peak velocity in the innominate vein in the 11 anemic patients with venous hum (supine; 71 +/- 12, sitting; 111 +/- 24 cm/sec, mean +/- SD) than in the control subjects (supine; 46 +/- 15 sitting; 76 +/- 27 cm/sec) in both positions. Intensity of venous hum increased concomitantly with increased innominate vein flow velocity when the body position was changed from supine to sitting. Peak velocity in the innominate vein correlated significantly with Hb in all study subjects (r = 0.65, p less than 0.01). In conclusion, the cervical venous hum in patients with chronic anemia is related to the hemoglobin concentration and flow velocity in the innominate vein.

Adolescent↗
PubMed1989

Effects of interocular blur suppression ability on monovision task performance.

Suppression of anisometropic blur induced by monovision contact lenses was examined in 18 presbyopic subjects. Suppression ability was quantified by reducing the contrast of a bright test target, viewed by subjects wearing a monovision correction, until the blurred image was suppressed. Subjective success with monovision was evaluated using a patient survey and no correlation to blur suppression ability was found. Objective success was evaluated in terms of performance at three near work tasks, each requiring a different level of stereoscopic localization. A significant correlation was found between card filing performance (requiring a moderate level of stereopsis) and blur suppression ability. Correcting either the dominant or non-dominant eye for near in the monovision correction did not significantly affect blur suppression ability. There was no evidence for adaptation to monovision in terms of increasing blur suppression ability over time.

Adult↗
PubMed1989

[A case of intramedullary spinal cavitation after minor trauma].

A case of surgically treated intramedullary spinal cavity which appeared 1 year after a minor injury was presented. A 15 year-old boy developed nuchalgia and muscle weakness of his right arm and leg. On admission, he had right hemiparesis and sensory disturbances in the right C6-C8 and left T1-S5 dermatomes. Metrizamide-CT scan and MRI disclosed an intramedullary spinal cavity between C4-C5 vertebral levels. A myelotomy and a biopsy of the cavity wall were carried out in order to communicate the cavity with the subarachnoid space, and to make a definite diagnosis. The microscopic examination of a biopsy specimen revealed no tumor findings but inflammation. Taking into account the location of the cavity, a site corresponding with the site of a previous trauma, the authors finally diagnosed the cavity as intramedullary spinal cavitation after minor trauma. His symptoms improved remarkably after the operation.

Adolescent↗
PubMed1988

A novel sodium channel inhibitor from Conus geographus: purification, structure, and pharmacological properties.

A novel toxin, tentatively named conotoxin GS (CGS), has been isolated from a marine snail, Conus geographus. CGS was found to exist as a single polypeptide chain, consisting of 34 amino acid residues, cross-linked by three disulfide bonds. Its amino acid sequence was shown to be Ala-Cys-Ser-Gly-Arg-Gly-Ser-Arg-Cys-Hyp-Hyp-Gln-Cys-Cys-Met-Gly-Leu-Arg- Cys-Gly - Arg-Gly-Asn-Pro-Gln-Lys-Cys-Ile-Gly-Ala-His-Gla-Asp-Val. In competition experiments, CGS inhibited the bindings of [3H]Lys-tetrodotoxin ([3H]Lys-TTX) and [3H]propionylconotoxin GIIIA to Electrophorus electricus electroplax membranes, with Ki values of 34 nM and 24 nM, respectively. The toxin inhibited the binding of [3H]Lys-TTX (1 nM) to rat skeletal muscle homogenates with an IC50 value of 880 nM but showed very little effect on this binding to the rat brain P2 fraction at 10 microM. These binding studies indicate that CGS belongs to the same group of Na channel inhibitors as TTX, STX (saxitoxin), and mu-conotoxins. Although CGS, like the mu-conotoxins, is a pharmacological probe for distinguishing between neuronal and muscle Na channel subtypes, the homology in the sequences of CGS and mu-conotoxins is very limited.

Amino Acid Sequence↗
PubMed1988

Experiences with CT-guided stereotaxic biopsies in 121 cases.

Needle biopsy using a CT-guided stereotaxic technique was performed in 121 cases of suspected brain tumour. Using this technique, it is possible to perform biopsies safely and accurately on even small and deep-seated lesions with a minimum of surgical intervention. However, accurate diagnoses are sometimes not possible when only a small number of viable cells are obtained, such as in lesions containing old haematoma, cystic tumours, previously treated tumours or tumours which are either too hard or too soft. We were able to make accurate diagnoses in 98 of our 121 cases (81%). The accuracy of diagnosis is somewhat hampered by the small volume of sample material obtained using this biopsy technique, and this fact should be kept in mind when evaluating the histological material.

Adolescent↗
PubMed1988

Immunohistochemical study of Rathke's cleft cyst.

An immunohistochemical study was made of ten cases of asymptomatic and three cases of symptomatic Rathke's cleft cyst. The cysts in the asymptomatic cases had monolayer columnar or cuboidal epithelium. Within the epithelium, cells which were positive for at least one of the pituitary hormones were found. The rate of positive reactions for these six pituitary hormones was between 70% and 100%. In contrast, the cysts in the symptomatic cases had an epithelium which was partly stratified squamous and partly squamous epithelium, and none of the pituitary hormones were found in them. Therefore, when a Rathke's cleft cyst enlarges to the extent that clinical symptoms are produced, we consider that changes have already occurred in structure and function of the cyst epithelium. In addition, we believe there is a tendency for monolayer epithelia to undergo squamous metaplasia and for cells which are positive for pituitary hormones to change into non-granulated cells.

Aged↗
PubMed1988

The development and morphogenesis of the human pituitary gland.

In order to clarify the environmental factors which are involved in the development of the primordium of the pituitary gland such as cell-cell interactions, a three-dimensional reconstruction of this organ and its surrounding tissues was carried out. Pituitary material was obtained from human fetuses mainly during the period of organogenesis. Rathke's diverticulum was found to stretch rostrally from the stomodeal epithelium to the middle of the mesoderm, and already by the 5th week of fetal growth, it was clearly seen to be involved with the diencephalon. The area of contact between Rathke's pouch and the diencephalon gradually moved from the rostral to caudal regions and, after 13 weeks of development, had a position similar to that found in the newborn infant. Among the cells forming Rathke's pouch, it was found that the closer their relationship was to the diencephalon, the greater were their epithelial characteristics. When the relationship of such cells to the diencephalon was weaker, their differentiation to endocrine cells occurred earlier. Immunohistochemically, that portion of the pituitary primordium which has a close relationship with the diencephalon, later to become the pars intermedia, showed an adrenocorticotropic hormone (ACTH) immunoreactivity later than that of the pars anterior. On the other hand, in the 21st fetal week, nearly all of the cells of the pars intermedia were found to be ACTH-positive. This finding is thought to indicate a close connection between the physical contact between the brain (diencephalon) and the pituitary primordium and the development of the pars intermedia; the differentiation of ACTH cells. The surface of the epithelium of Rathke's cavity continues to increase at least until the 21st fetal week, so the growth of the epithelium of Rathke's pouch is thought to be heavily involved in the growth of the primordium of the pituitary gland in the early stages of development.

Cell Communication↗
PubMed1988

Bifrontal interhemispheric approach for carotid-ophthalmic aneurysms.

The authors report their experience with the surgical treatment of carotid-ophthalmic aneurysms in 29 cases, and describe their surgical technique. The technique can be summarized as follows. When dissecting the aneurysm, temporary vascular occlusion of the common carotid artery and external carotid artery is done in the neck under the administration of cerebral protective substances. Through a bifrontal craniotomy, wide dissection of the Sylvian fissures and the interhemispheric fissure is performed. When necessary, the anterior clinoid process and the roof of the optic canal are removed. This approach allows for observation of the neck of the aneurysm from various angles, thus facilitating clipping of the neck. There have been no previous reports of direct surgery on carotid-ophthalmic aneurysms using an interhemispheric approach, but this approach provides a much larger operative field and a better exposure of the aneurysm than other surgical approaches.

Adult↗
PubMed1988

Intracerebral hemorrhage from a metastatic brain tumor. Importance of differential diagnosis preceding stereotaxic hematoma aspiration.

Three cases of sudden intracerebral hemorrhage, which were diagnosed as hemorrhage from metastatic brain tumors following stereotaxic aspiration of a hematoma, are reported. Two cases had subcortical hemorrhage and one had cerebellar hemorrhage. Neither contrast-enhanced computed tomography scans nor angiograms revealed any findings other than those indicating the hematoma in all three cases. However, retrospective study of the anamnesis showed very mild symptoms due to metastasis to the brain or spinal cord in one case each. In cases of intracerebral hematoma located at atypical sites, extreme care is required for the differential diagnosis.

Adenocarcinoma↗
PubMed1988

Photochemical mutagen formation from aerobically treated night-soil effluent and the contributive substances.

Effluents from a night-soil treatment plant, where night-soil was aerobically treated by an activated sludge process, were irradiated with a UV lamp excluding short wavelengths less than 300 nm as a model of exposure to sunlight and the mutagenicities of the ethylacetate extracts from the irradiated effluents were assayed using Salmonella typhimurium TA98. The extracts exhibited mutagenicity toward S. typhimurium TA98 in the absence of rat liver S9 fraction only when the effluents were fortified with nitrite ion (more than 6 ppm) by over aeration or by artificial addition of nitrite, indicating that a limiting factor for mutagen formation is nitrite ion concentration. Nine organic-N-containing compounds as models of the organic components in the effluent were also irradiated and direct-acting potent mutagens were found to be produced from such compounds having indole moiety as indole, oxindole, tryptophan and tryptamine.

Journal Article↗
PubMed1988

Superior protective effects of phenytoin against hypoxia in a pharmacological screening test.

The selection of drugs to prevent the development of pathology in cerebral infarction remains an important problem. For the selection of effective drugs from among a large number of possible candidates, widely-used test screening techniques are sufficient for obtaining a good understanding of candidate drug effects. The effects of various drugs on the survival time of mice made hypoxic by exposure to a 4% O2-96% N2 gas have been examined. The survival time of 110 control animals was 170 +/- 6 s, showing a nearly normal distribution pattern. No control mouse had a survival time beyond 8 min. The survival time after the drugs were administered was as follows: suloctidil (12.5 mg/kg, n = 11), 1833 +/- 487 s; vitamin E (200 mg/kg, n = 15), 1160 +/- 342 s; pentobarbital (50 mg/kg, n = 12), 602 +/- 74 s; and phenytoin (100 mg/kg, n = 10), 2667 +/- 452 s. In contrast, administration of vitamin C, coenzyme Q, cytochrome c, beta-methasone, mannitol or germanium-132 did not result in prolongation of survival time. Comparison of the percentage of animals in each group which survived for more than 1 h showed 0% in the control group, 45.5% in the suloctidil group (12.5 mg/kg), 23.5% in the vitamin E group (200 mg/kg), 0% in the pentobarbital group (50 mg/kg) and 70% in the phenytoin group (100 mg/kg). These findings suggest that phenytoin is the most effective drug in combatting the effects of hypoxia (survival time was expressed as mean +/- SE).

Animals↗
PubMed1988

The protective effect of mannitol, vitamin E and glucocorticoid on ischaemic brain injury: evaluation by chemiluminescence, energy metabolism and water content.

We currently have used three drugs in combination [mannitol, vitamin E and glucocorticoid (beta-methasone)] for the treatment of cerebral infarction in the acute stage. For the purpose of evaluating the efficacy of this therapy, we have conducted experiments evaluated by chemiluminescence (CL), energy metabolism and water content of the cortex using a global highly ischaemic rat brain. During the ischaemic period, CL levels increased with time and further increases were seen after recirculation of the blood flow. However, in the group which was administered the three drugs in combination, there was marked inhibition of CL value. Determination of adenine nucleotide and carbohydrate levels revealed that these drugs in combination promoted their recovery at the time of recirculation following ischaemia. In particular, the increase in lactate was inhibited during the ischaemia, thus preventing the progression of lactic acidosis. Moreover, in the group given all three drugs and in the group given 20% or isotonic mannitol, the increase in cortical water content following recirculation was inhibited. From these results it is deduced that these three drugs inhibit the cellular destruction by attenuation of free radical mediated peroxidation.

Adenine Nucleotides↗
PubMed1988

Cerebral protective effect of flunarizine in a canine model of cerebral ischaemia.

To test the effect of flunarizine on cerebral ischaemia, 15 dogs were subjected to ischaemia, using the 'canine model of the completely ischaemic brain regulated with a perfusion method' in which the cerebral blood flow (CBF) can be fully regulated. Five animals served as untreated controls, 10 received flunarizine, a calcium antagonist (1 mg/kg in 5 dogs and 3 mg/kg in 5 dogs), before the ischaemic period. After 1 h CBF was restored and recovery of the electrical activity of the brain and the degree of brain swelling were observed for 3 h. At the end of the experiments, the degree of extravasation of Evans blue was examined. Remarkable recovery of EEG was found in the groups given flunarizine when compared with untreated controls. However, no significant difference was found between untreated controls and flunarizine treated groups for the degree of brain swelling and the degree of extravasation of Evans blue. These results suggest that the treatment of flunarizine is of benefit for functional recovery against cerebral ischaemia, but does not suppress ischaemic brain oedema.

Animals↗
PubMed1988

Correlation among lipid peroxidation, brain energy metabolism and brain oedema in cerebral ischaemia.

In order to study the involvement of lipid peroxidation in the generation of ischaemic cell damage, sequential measurements were made on the chemiluminescence, energy metabolism, water content and the volume of Na+ and K+ in the cerebral cortex using a rat model for severe cerebral ischaemia. It was found that the amount of chemiluminescence increased due to ischaemia and increased further following recirculation. In chemiluminescence spectral analysis, peaks were found at 480, 520-530, 570, 620-640, 680-700 nm. It is thought that these wavelengths reflect the release of energy due to the reduction of active oxygens to more stable states during the breakdown of lipid hydroperoxide. The recovery of ATP in the 5 min ischaemic brain after reflow with ATP stopped at approx. 60% of the pre-ischaemia level, whereas the water content of the cortex showed an increase after 5 min of recirculation, and a gradual recovery thereafter for 30 min. There was a strong correlation between the increase in cortical water content after recirculation and the amount of chemiluminescence. It is concluded that causes of the ischaemic cerebral oedema include not only decreased activation of ATP-dependent Na+, K+-ATPase, but also functional changes in ion channels due to an increase in free radicals following recirculation.

Adenosine Diphosphate↗
PubMed1988

Heterogeneity of hemolytic efficiency and isoelectric point of streptolysin O.

Using thin-layer agarose gel isoelectric focusing overlaid with thin-layer erythrocyte agar plates, we found that crude streptolysin O (SLO) consisted of a variety of hemolytic components with different isoelectric points (pIs) and that the distribution of pIs in crude SLO was different even in samples which were produced from a single strain of Streptococcus pyogenes under similar conditions. All of the hemolytic components in crude SLO were shown to have the properties of SLO with respect to their susceptibility to oxygen and anti-SLO serum and their molecular weight. The SLO components showed a single molecular weight of 64,000, but they exhibited various pIs ranging from pH 5.4 to 8.3, with major components showing a pI of 6 and/or 7.5. Further examination revealed the slope of the hemolytic titration curve to be dissimilar among the samples of crude SLO. Since the slope of the hemolytic titration curve of a component appears to be based on its hemolytic efficiency, the value of the slope was designated its hemolytic efficiency index. When SLO was purified by isoelectric focusing, the pI of the components was correlated with its hemolytic efficiency index; hemolytic components with lower pIs exhibited a lower hemolytic efficiency index. These results indicate that SLO consists of heterogeneous components with different pIs and suggest that the differences in hemolytic efficiency indices of SLO components are due to the different electrical charges of SLO molecules, which are related to their polymerization and affect hemolytic efficiency.

Animals↗
PubMed1988

Assessment of the thickness of the right ventricular free wall by magnetic resonance imaging in patients with hypertrophic cardiomyopathy.

Electrocardiogram gated magnetic resonance imaging was performed in nine healthy volunteers, in four patients with pulmonary hypertension, and in 16 patients with hypertrophic cardiomyopathy. Fifty two short axis images in diastole were examined to assess the usefulness of magnetic resonance imaging for the measurement of the thickness of the free wall of the right ventricle and the degree of hypertrophy of the right ventricular free wall in hypertrophic cardiomyopathy and pulmonary hypertension. Magnetic resonance imaging gave a clear image of 68% of the length of the right ventricular free wall, showing both the endocardial and epicardial margins. The mean (1 SD) thickness of the right ventricular free wall measured at a total of 512 points was 0.44 (0.12) cm in patients with hypertrophic cardiomyopathy, 0.29 (0.08) cm in healthy individuals, and 0.73 (0.27) cm in patients with pulmonary hypertension.

Cardiomyopathy, Hypertrophic↗
PubMed1988

Lack of effect from a single cigarette challenge on bronchial responsiveness in healthy non-smoking subjects.

The effect of smoking a cigarette on bronchial responsiveness was studied in healthy non-smokers. Twenty two subjects performed a methacholine inhalation test before and after smoking a single cigarette. Ten of the subjects took part in a further study in which propranolol was inhaled before the smoking challenge to diminish the baseline beta adrenergic tone of the airway. After they had smoked a single filtered or non-filtered cigarette the indices of bronchial responsiveness (the cumulative dose of methacholine starting a decrease in the reciprocal of resistance, Grs (Dmin), and the cumulative dose causing a 35% drop in the Grs (PD35Grs)) did not change significantly. With the inhalation of propranolol mean (SD) log Dmin decreased from 1.37 (0.44) units to 0.74 (0.57) (p less than 0.01) and log PD35Grs from 1.93 (0.38) to 1.51 (0.38) (p less than 0.01). Smoking a single cigarette after the inhalation of propranolol did not, however, cause any further change in bronchial responsiveness. This study suggests that smoking a single filtered or non-filtered cigarette does not change bronchial responsiveness in non-smokers, and that changes in beta adrenergic tone of the airway do not modify the effect of smoking a single cigarette on bronchial responsiveness.

Adult↗