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Biomedical subjects

Y Koike

Publications and source records attributed to Y Koike.

At least 253 records · Page 14Linked to original sources
PubMed1990

[Measurement of blood flow in human tympanic membrane with spectrophotometry and laser speckle flow meter].

The purpose of this study is to evaluate the blood volume and blood flow in human tympanic membrane. Hemoglobin concentration (IHb) and oxygen saturation of hemoglobin (ISO2) were measured in 71 ears by using a tissue spectrum analyzer. Blood flow (Flow level) was measured in 40 ears by using a laser speckle flow meter. By using two fiber optic probes, these three parameters were measured in the tense part of the tympanic membrane. A comparison was made between the measurements made with fiber probe touching the tympanic membrane and the measurements not touching it. Between two measuring patterns, there was no significant differentiation in three parameters, so we took non-touching technique. IHb and Flow level had reproducibility between the first and second recordings. But ISO2 did not have clear reproducibility. In normal tympanic membrane, IHb and Flow level were not significantly correlated (r = 0.52). IHb was 16 +/- 1.3 (Mean +/- SEM) in normal cases, 17 +/- 4.6 in otitis media with effusion and 104 +/- 22.8 in acute otitis media. Flow level was 0.7 +/- 0.07 in normal cases, 0.6 +/- 0.07 in otitis media with effusion and 2.2 +/- 0.37 in acute otitis media. It is considered that the measurement of hemoglobin concentration by using tissue spectrum analyzer and the measurement of blood flow by using laser speckle flow meter are useful in the studies of the pathophysiology of human tympanic membrane.

Adolescent↗
PubMed1990

[Measurement of human laryngeal mucosal blood volume].

To the best of our knowledge little if any information is available concerning human laryngeal mucosal blood volume presumably because the larynx is an anatomical position which renders the measurement of blood flow there difficult. With the advent of a reflectance spectrophotometer, however, studies of tissue blood flow have been facilitated to a great extent. As a result, attempts have been made to determine mucosal blood volume in various organs and tissues including the gastric mucosa. Recently, an ultra-thin fiber probe (1.8 m min diameter) for measurement of tissue blood volume has been developed. Using a laryngeal flexible fiberscope attached with this newly developed probe in the opening for the forceps, an attempt was made to measure laryngeal mucosal blood volume by the method of reflectance spectrophotometry, determining IHb and ISO2 the former of which is a parameter of hemoglobin in the tissue blood vessels and the latter, a parameter of hemoglobin oxygen saturation in the tissue blood vessels. IHb of the vocal folds is significantly low, about half those of the false folds and arytenoid region, whereas ISO2 is significantly higher in the false folds and arytenoid region than in the vocal folds. The hemodynamics in the vocal folds as a high-speed vibrator are specific, unlike in other laryngeal regions. We have plans to determine laryngeal tissue blood volume at more sites so as to investigate the laryngeal tissue distribution of blood volume in greater detail. Furthermore, tissue blood volume in morbid conditions will also be determined for information which will be of value in clinical applications.

Adult↗
PubMed1990

[Effects of high dose steroid on the experimentally induced facial palsy].

As a conservative treatment for Bell's palsy, the high dose steroid therapy introduced by Stennert in 1982 are highly evaluated clinically from many investigators. In the present study, model animals with experimentally-induced facial paralysis were prepared using guinea pigs in which the effect of administration of high dose steroid on the recovery process of the palsy was investigated electrophysiologically and morphologically. The main trunk of the facial nerve was exposed under Nembutal anesthesia, and compressed for 10 sec. using a needle holder. The model animals were divided into three groups, a high dose steroid group (Group A) and a low dose steroid group (Group B) and control group (Group C). The evoked EMGs of orbicularis oris muscle were recorded before operation and on the third, seventh and 14th days after operation, and each time course of the amplitude changes in Groups A, B and C was compared. Recovery patterns of amplitude in Group A was much more rapid than in Groups B and C. Light microscopy revealed extensive destruction and existence of only a small number of normal myelinated fibers on the 14th day after operation in Group C. In Group A, however, these changes were slight. And the numbers of normal myelinated fibers decreased to a minimum in Group C, while the number of fibers in Group A already increased on the 14th day. Electron microscopy, in Group C, disclosed distortion of the sheath of myelinated fibers and abnormal changes in the axon. But in Group A, dense lamellar structure of myelin sheath and no axonal degeneration were disclosed. These experimental results support the efficacy of high dose steroid therapy upon Bell's palsy.

Animals↗
PubMed1990

Immunolocalization of heparan sulfate proteoglycans to the prion protein amyloid plaques of Gerstmann-Straussler syndrome, Creutzfeldt-Jakob disease and scrapie.

Previous histochemical studies have demonstrated highly sulfated glycosaminoglycans (GAGs) localized to the amyloid plaques in the brains of humans and animals with prion diseases (Snow et al., Acta Neuropathol 77:337, 1989). However, the identity of the specific class of proteoglycan/GAG present was not known. The current investigation used immunocytochemical techniques to identify and localize heparan sulfate proteoglycans (HSPGs) in human cases of Gerstmann-Straussler syndrome and Creutzfeldt-Jakob disease, as well as in experimental scrapie of hamsters. Polyclonal and monoclonal antibodies to either the protein core or GAG moiety of the basement membrane-derived HSPG were utilized. The results demonstrate that both the protein core and the GAG chains of HSPGs are immunolocalized to the prion protein amyloid plaques in each of these diseases. HSPG immunostaining was also evident in these tissues in blood vessels, choroid plexus, myelinated axons, and in the cytoplasm of certain neuronal and astrocytic populations, particularly those in close proximity to the amyloid plaques. Additionally, in Creutzfeldt-Jakob disease and Gerstmann-Straussler syndrome cerebellum, positive immunostaining for heparan sulfate GAGs was observed within the cell bodies of Purkinje cells. The specific accumulation of HSPGs in the amyloid deposits of both the prion diseases and Alzheimer's disease (Snow et al., Am J Pathol 133:456, 1988), suggests that a common mechanism involving HSPGs may occur in the pathogenesis of amyloidosis in each of these diseases.

Amyloid↗
PubMed1990

[Effects of ethanol on GTP binding protein function in rat cerebral cortex: strain difference between Wistar and Fischer 344 rats].

The effect of ethanol on GTP-binding protein of cortical adenylate cyclase (AC) system in the Wistar and Fischer 344 rats was examined. In both Wistar and Fischer 344 rats, ethanol (100mM) potentiated Gpp (NH) p-stimulated AC activity and decreased EC50 for Gpp (NH)p in the cerebral cortical membrane (CCM). Ethanol treatment also augmented Mn-stimulated AC activity in Wistar CCM, whereas there was no significant change in Fischer 344 CCM. IC50 calculated from the Gpp (NH)p (0.01-0.3 microM) inhibition of forskolin-stimulated AC was decreased by ethanol treatment in Wistar CCM, but this was not the case in Fischer 344 CCM. There was no appreciable change in ADP-ribosylation of Gs and Gi in CCM with pertussis or cholera toxin. These results suggest that ethanol in vitro enhances the Gi function as well as affecting the Gs function in Wistar rat cortical AC system, and the effect of ethanol on Gi protein are different in Wistar and Fischer 344 CCM.

Adenylyl Cyclases↗
PubMed1990

Early accumulation of heparan sulfate in neurons and in the beta-amyloid protein-containing lesions of Alzheimer's disease and Down's syndrome.

A monoclonal antibody (HK-249) that recognizes a glucosamine sulfate alpha 1----4 glucuronic acid-containing determinant in heparan sulfate (HS) chains of a basement membrane-derived heparan sulfate proteoglycan identified and immunolocalized HS specifically to the amyloid deposits in neuritic plaques (NPs), congophilic angiopathy (CA), as well as in neurofibrillary tangles (NFTs) and non-tangle-bearing neurons in the brains of Alzheimer's and Down's syndrome (DS) patients. Ultrastructural immunohistochemistry demonstrated that HS within neurons of Alzheimer's disease (AD) brain was localized to lipofuscin granules, an aging pigment previously shown also to contain beta-amyloid protein (BAP). Heparan sulfate also was localized to neurite-containing, nonfibrillar 'primitive' plaques that also demonstrated positive BAP immunoreactivity in both AD and DS brains. Antibodies to laminin, fibronectin, and a chondroitin sulfate proteoglycan failed to show positive immunostaining of the HS-containing sites described above. Analysis of DS patients at different ages revealed that HS accumulated within neurons of the hippocampus and amygdala as early as 1 day after birth. Young age-matched controls did not demonstrate similar positive HS immunoreactivity in neurons, whereas positive immunostaining for HS was observed in other regions thought to normally contain HS. The earliest deposition of BAP was first observed as 'amorphous' or 'diffuse' cortical deposits in DS brain in patients aged 18 and 24 years before the accumulation of fibrillar amyloid (observed in DS patients who are 35 years and older). These cortical deposits also contained positive HS immunoreactivity, implying that HS accumulation in conjunction with the BAP is an early event that ultimately may contribute to the early age-related accumulation (ie, as early as 35 years of age in DS) of NPs, NFTs, and/or CA. Furthermore the colocalization of HS and BAP in a number of specific locales in AD and DS brain indicates a possible interaction between these two macromolecules that may be important in lesion development in these two diseases.

Adolescent↗
PubMed1990

[Vasopressin effect and pathophysiological analysis on postprandial hypotension].

In order to clarify the effect of arginine vasopressin (AVP) on postprandial hypotension (PPH) in patients with multiple system atrophy, a loading test of 75 g glucose in 225 ml water was performed during infusion of AVP (0.3 U/min). AVP (0.3 U/min) infusion prior to the loading was significantly effective for PPH in all patients: PPH following to oral intake of glucose was completely prevented. We conclude that infusion of AVP maintained circulating systemic blood volumes by reduced portal venous flow (after a reduction of portal venous inflow) as a result of vasoconstrictive effect of AVP on the splanchnic vessels in patients with PPH.

Adult↗
PubMed1989

[Diagnostic imaging of gallbladder carcinomas with special reference to ultrasonographic findings. Retrospective review with emphasis on diagnostic problems in preoperatively undiagnosed gallbladder carcinomas].

The diagnostic images of twenty surgically-resected gallbladder carcinomas were retrospectively reviewed for correlations with macroscopic findings. Among them, nine cases were correctly diagnosed preoperatively; 11 were not. Macroscopically, all correctly diagnosed lesions were elevated type carcinomas. Preoperatively undiagnosed lesions were comprised by 9 superficial and 2 elevated types of carcinomas. None of these 11 undiagnosed carcinomas could be identified on retrospective review of the ultrasonographic findings. Thorough evaluation of the gallbladder wall was prevented by gallstones and/or emphysema in 6 cases, and by contraction of the gallbladder in 4 cases. There was no definite evidence of wall thickening in one case of diffuse superficial carcinoma involving the muscle layer. As for lesion detectability, computed tomography was inferior to ultrasonography, though the former demonstrated localized wall thickening of the gallbladder in the majority of cases of elevated type carcinomas. Intravenous cholangiographic findings were non-specific.

Adenocarcinoma↗
PubMed1989

A novel nonpeptidic, orally active renin inhibitor.

BW-175 is a newly synthesized renin inhibitor which is a nonpeptidic, norleucine analog. Its IC50 values for renin activity in human, squirrel monkey, marmoset, dog, hog, rabbit and rat plasma were 3.3, 6.6, 2.4, 42, 110, 86 and 3500 nM, respectively, and 26 microM for cathepsin D. Pepsin and angiotensin converting enzyme were hardly inhibited at 10(-4) M. BW-175 showed an oral bioavailability of 2.8% at 10 mg/kg and 9.7% at 30 mg/kg in rats. In normotensive, furosemide-treated high-renin marmosets, BW-175 (30 mg/kg p.o.) caused an intensive reduction in plasma renin activity and plasma angiotensin I formation, associated with a reduction in systolic blood pressure of 10-20 mm Hg for 2 hours.

Aminocaproates↗
PubMed1989

Effects of traxanox sodium on blood pressure and serum uric acid in hypertensive patients: a preliminary study.

The effects of chronic administration of traxanox sodium (traxanox) on blood pressure and serum uric acid level were investigated in 15 patients who had mild to moderate hypertension. Traxanox or its placebo was orally administered in a single-blind protocol. Blood pressure was significantly reduced from baseline after treatment with traxanox. The serum uric acid level after drug administration was significantly lower than with placebo whereas urinary uric acid excretion was significantly greater and uric acid clearance tended to be greater. These results indicate that chronic administration of traxanox reduces serum uric acid level as well as blood pressure in patients with mild to moderate hypertension. This reduction in serum uric acid is due in part to a traxanox-induced elevation of urinary uric acid excretion.

Adult↗
PubMed1989

Demonstration by lectin cytochemistry of rod and cone photoreceptors in the lamprey retina.

Lectin cytochemical analysis was undertaken to examine the distribution of glycoconjugates associated with the short and long photoreceptor cells in the lamprey retina. Concanavalin A bound preferentially to the outer segment region of the short cells. Wheat germ agglutinin bound weakly to both long and short cells. The outer segment regions of the long cells were stained intensely with peanut agglutinin. Pretreatment with neuraminidase to remove sialic acid resulted in decreased binding of wheat germ agglutinin throughout the retina and increased binding of peanut agglutinin to the outer segment region of the short cells and the region of myoid process of the long cells. These results suggest that there is a difference in the distribution of glycoconjugate residues between the long and short cells. A rod-like character of the short cell and a cone-like character of the long are tentatively discussed. Lectin-binding patterns in other retinal regions is also examined.

Animals↗
PubMed1989

Combined effects of vibration and noise on palmar sweating in healthy subjects.

The combined effects of vibration and noise on palmar sweating were studied experimentally in healthy subjects. Ten subjects were exposed to vibration at an acceleration of 100 m.sec-2 root mean square at a frequency of 125 Hz, a noise level of 105 dB(A) at a frequency of 1000 Hz and both stimuli together. Vibration was applied to the right hand and noise to both ears from headphones. Palmar sweating was measured by the ventilated capsule method. Vibration caused a marked increase in palmar sweating of the right hand directly exposed to vibration and also of the left hand not exposed to vibration. Simultaneous vibration and noise caused a greater increase in palmar sweating than by each of the factors separately. The combined effects tended to be greater in subjects who were more susceptible to vibration or noise.

Adult↗
PubMed1989

Induction of physical dependence on pentobarbital by new infusion method in the rat.

1. A new intermittent intravenous infusion method was developed for the induction of tolerance to and physical dependence on pentobarbital in rats. 2. Female and male rats were injected with pentobarbital (20 mg/kg/injection) through an implanted intravenous cannula. 3. The rats were allowed to receive an injection after the completion of a fixed amount of behavioral activity counted from the preceding injection, and therefore, the sedative and hypnotic effects of pentobarbital were used as an index in the determination of the injection intervals. 4. During pentobarbital treatment, the number of pentobarbital injections per day rapidly increased and stabilized (approximately 40: male, approximately 30: female) on the third to fifth day. 5. Upon withdrawal, the female and male rats who were maintained on pentobarbital administration of more than 30 and 40 injections/day for approximately 10 days manifested withdrawal signs which included spontaneous convulsion. 6. These results suggest that a new infusion method exists to produce a high degree of physical dependence in rats on a short-acting barbiturates, pentobarbital.

Animals↗
PubMed1989

Kidney-preserving radical tumor resection in advanced neuroblastoma.

The possibility of kidney-preserving radical tumor resection in advanced neuroblastoma was evaluated. Eighteen patients with stage III and IV adrenal neuroblastoma underwent delayed primary surgery after chemotherapy consisting of high doses of cyclophosphamide (1,250 mg/m2). Radical tumor resection with nephrectomy was performed in 13 patients (group A) and kidney-preserving radical tumor resection was performed in six patients (group B). Macroscopic findings were evaluated in all patients; angiographic and microscopic findings were evaluated in group A patients and tumor recurrence in group B patients. Macroscopically, the tumors were observed within the tumor capsule (C1) in five, outside the tumor capsule but not beyond the midline (C2) in seven, and beyond the midline (C3) in six. In group A, under microscopic examination, the tumor invasion into the renal parenchyma was observed in only three patients among C2 and C3 cases. Tumor vessels from the capsular and/or perforating arteries plus from the intrarenal arteries could be visualized in all patients, three of whom had tumor invasion into the renal parenchyma. In group B, no tumor recurrence around the kidney occurred, and two patients have survived for greater than 2 years. The kidney-preserving radical tumor resection is recommended in surgical treatment of advanced neuroblastoma following preoperative chemotherapy, and is predictable preoperatively by angiography.

Adrenal Gland Neoplasms↗
PubMed1989

Purification of human alpha 2-plasmin inhibitor using monoclonal antibody column chromatography.

alpha 2-Plasmin inhibitor (alpha 2PI) was purified directly from human plasma by using a monoclonal antibody affinity column, which recognizes the reactive site of alpha 2PI. alpha 2PI was eluted from the column under mild conditions with 50% v/v ethyleneglycol containing 0.05% Tween 80 in phosphate-buffered saline, pH 7.4. The yield was around 50% and the specific activity of the purified protein was the same as that of the best product of preparation conventionally purified alpha 2PI.

Antibodies, Monoclonal↗
PubMed1989

Reaction times of movement preparation in patients with Parkinson's disease.

We studied the onset of preparatory postural responses and subsequent voluntary movements by measuring soleus muscle activities in the standing position in 20 patients with Parkinson's disease. We measured the postural response in preparing to rise on tiptoe as the onset of the premotion silent period (PMSP). Our patients showed no delay when compared with age-matched healthy controls, but did show a significant delay in the onset of voluntary movement. The elongated PMSP (increased duration of the preparatory postural adjustments) was related to the severity of bradykinesia. Results indicate that the conventional reaction time is increased in patients with Parkinson's disease, even though there is no delay of central processing for the preparation of voluntary movements, and that there is bradykinesia of involuntary postural movements.

Adult↗
PubMed1989

Comparative study on computed tomography and neurotological findings in spinocerebellar degeneration.

The classification of SCD on the basis of the neurotological findings was with classification based on CT findings in 40 cass of SCD. The areas of pons, cerebellar hemisphere, vermis and posterior fossa on CT films were measured by craniometer, and were compared in order to estimate the degree of atrophy. From these assessments, patients were classified into 3 types as follows; (1) 14 cases of cerebellar type, (2) 9 cases of brain stem type and (3) 17 cases of combined type. The classification of SCD based on the neurotological findings including the findings of gaze test, positioning test, eye tracking test, OKN, and fixation suppression test of caloric nystagmus, was well correlated to the classification based on CT findings. From the results, neurotological examination was demonstrated to make a contribution to the estimation of lesions and types in SCD.

Caloric Tests↗