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Biomedical subjects

Y Koike

Publications and source records attributed to Y Koike.

At least 199 records · Page 11Linked to original sources
PubMed1994

[Changes of arterial CO2 (PaCO2) and urine output by carbon dioxide insufflation of the peritoneal cavity during laparoscopic cholecystectomy].

We studied on the effects of carbon dioxide insufflation during laparoscopic cholecystectomy on the arterial blood gas analysis and urine output. Intra-abdominal pressure was increased up to either 10cmH2O or 15cmH2O, and we compared the PaCO2 values before and during insufflation. Both increase of PaCO2 and decrease in pH were larger in intra-abdominal pressure of 15cmH2O than 10cmH2O. In the intra-abdominal pressure 15cmH2O group, the increase of PaCO2 by CO2 peritoneal insufflation was significantly larger in operative time of more than 60 minutes group than in less than 60 minutes group, but no significant changes were observed in 10cmH2O group. In the group of obesity index of more than 120, elevation levels of PaCO2 by CO2 insufflation were significant, but in the group of less than 120 no significant elevation were observed. The tendency that the urine output during operation was decreased as increase of intra-abdominal pressure or operative time, but the obesity had no definite effects on urine output. Insufflation of the abdomen with CO2 caused large changes in PaCO2 or pH in the patients with a previous history of major cardiopulmonary disorder. It was shown that the low insufflation pressure and short operative time is good for the maintenance of normal physiological state.

Adult↗
PubMed1994

Diagnostic specificity of anti-neutrophil cytoplasmic antibodies (ANCA) in otorhinolaryngological diseases.

The incidence and titer of ANCA were examined with 871 sera from patients with otorhinolaryngological diseases at our hospital. The cytoplasmic pattern of ANCA (c-ANCA) whose titer was more than 16 was detected only in the sera of patients with Wegener's granulomatosis (WG). The incidence of c-ANCA in active WG was more than 90%. The perinuclear staining pattern of ANCA (p-ANCA) was detected in almost 40% of patients with Sjögren's syndrome, 2.0% of inflammatory diseases and 1.0% of tumorous diseases. A high diagnostic value of c-ANCA in WG was found in patients with otorhinolaryngological diseases.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1994

An experimental study on the generator of amplitude-modulation following response.

To clarify the contribution of the auditory cortex and the inferior colliculus to amplitude-modulation following response (AMFR), lesion experiments were conducted on 8 cats. Bilateral auditory cortices of 2 cats were aspirated, and the right inferior colliculus of 3 cats, and the left inferior colliculus of another 3 cats were electrocoagulated to make lesions. Auditory brainstem response (ABR) evoked by clicks and AMFR elicited with 1000 Hz sinusoidally amplitude-modulated tones, at modulation frequencies (MF) of 20-200 Hz in 20-Hz steps, were examined before and after making lesions. Stimulus intensity was fixed at 90 dB SPL in both responses. AMFR was detected by phase spectral analysis using fast Fourier transformation. No change was observed in the phase spectral analysis of AMFR after bilateral cortical lesions. Remarkable changes were observed in AMFRs at MFs lower than 80 Hz and 200 Hz after lesions in the ipsilateral inferior colliculus and at all MFs after contralateral lesions of the inferior colliculus, while no such change was observed in ABR. The results suggest that the auditory cortex is not the source of AMFR, but that the inferior colliculus has great impact on the generation of AMFR at modulation frequencies of 20 to 200 Hz.

Acoustic Stimulation↗
PubMed1993

Wheat germ agglutinin-induced intracellular calcium mobilization in human platelets: suppression by staurosporine and resistance to cyclic AMP inhibition.

The lectin wheat germ agglutinin (WGA) elicited a prompt and sharp increase in intracellular Ca2+ concentration in human platelets. The WGA-induced Ca2+ mobilization was markedly inhibited by a protein kinase inhibitor staurosporine, whereas Ca2+ mobilization by receptor-mediated agonists, including thrombin, platelet-activating factor, and arginine-vasopressin, was not. In contrast, the lectin-induced Ca2+ mobilization was resistant to cyclic AMP inhibition, compared with that induced by receptor-mediated agonists. These findings indicate that the mechanism of intracellular Ca2+ mobilization, or possibly phospholipase C activation, induced by WGA is different from that induced by receptor-mediated agonists in human platelets.

Alkaloids↗
PubMed1993

Treatment of postprandial hypotension with selective alpha 1 and beta 1 adrenergic agonists.

In order to treat postprandial hypotension (PPH), we orally administered a combination of denopamine (10 mg, a selective beta 1-adrenergic agonist) and midodrine-HCl (4 mg, a selective alpha 1-adrenergic agonist) to eight patients with autonomic failure (AF) prior to and after eating. When the patients were given 75 g glucose with 225 ml water without drugs, blood pressure fell subsequently, cardiac output (CO) was unchanged, and vascular resistance of the lower legs (LVR) decreased. However, concomitant administration of denopamine and midodrine-HCl prevented PPH and increased CO and LVR. The portal blood flow was not indifferent to the drugs. A marked increase in heart rate after drug administration was seen in some patients with AF, which reflects the supersensitivity to denopamine. Combined oral administration of denopamine and midodrine-HCl is a safe and useful therapy for PPH in patients with AF.

Adrenergic alpha-Agonists↗
PubMed1993

Postprandial hypotension: hemodynamic differences between multiple system atrophy and peripheral autonomic neuropathy.

To clarify the mechanism of postprandial hypotension (PPH), we performed hemodynamic investigation after oral glucose ingestion in ten patients with multiple system atrophy (MSA), three patients with peripheral autonomic neuropathy (PN) and 16 normal controls. Blood pressure (BP) and heart rate (HR) were measured with an automatic sphygmomanometer; cardiac out (CO) and lower leg blood flow (LBF) with impedance plethysmography; and portal blood flow (PBF) using a B-mode pulse Doppler. In normal subjects, BP, LBF and vascular resistance of the lower leg (LVR) were not changed, but HR slightly increased, and PBF and CO significantly increased after oral ingestion of 75 g glucose. In the patients with MSA, BP fell significantly 15 min after glucose ingestion, and HR and CO did not increase. PBF and LBF increased and LVR fell significantly. In PN patients, BP decreased at 15 min after glucose ingestion, but soon recovered. Increase of PBF and decrease of LVR in them were almost similar to those in the MSA group, and increase of CO was greater than that in the controls. These results suggest that both systemic vasodilatation (presumably due to gastrointestinal vasodilatatory peptides) and lack of compensatory increase of CO and LVR play important roles in PPH.

Administration, Oral↗
PubMed1993

Effect of optokinetic stimulation on human balance recovery in unexpected forward fall.

We examined whether optokinetic stimulation (OKS) affects balance recovery in an unexpected forward fall. Ten healthy male subjects participated in the study. Each was held in an initial, leaning-forward position supported by a cable connected to a strong magnet which enable unpredicted release. Instruction was given to move against forward fall by taking steps. To evaluate the relation between OKS velocities and balance recovery, ten stages of OKS velocities ranging from -100 (upward) degree/sec to +100 (downward) degree/sec were presented randomly. Balance recovery against forward fall was characterized by the reaction time, heel off, maximum vertical push, and heel contact. The latencies of these events decreased as the downward velocity of OKS increased; the latencies increased with the increment in the upward velocity of OKS. Changes in the latencies of the parameters took place in the early phase, in which the parameters of balance recovery depended little on the proprioceptive afferents from the lower limbs. This suggests that vection induced by the OKS affected the condition of the motor program which controls the initiation of the motor response. In other words, information from the visual system may modulate the condition of the motor program before the onset of movement.

Adult↗
PubMed1993

Optimal modulation frequency for amplitude-modulation following response in young children during sleep.

In young children, there appears to be no advantage to recording steady-state response (SSR) at a stimulus rate of 40 Hz. To determine the optimal modulation frequency in auditory SSR evoked by sinusoidally amplitude-modulated (SAM) tones (amplitude-modulation following response: AMFR) in children during sleep and compare response patterns of AMFR at different modulation frequencies while awake with those during sleep, AMFR was examined in 10 adults with normal hearing while awake and during sleep and in 10 young children with normal hearing during sleep. The stimulus was a 1000 Hz, 50 dBnHL SAM tone with a modulation depth of 95%. Modulation frequency was varied from 20 to 200 Hz in 20 Hz steps. Response was determined by phase spectral analysis and the S/N ratio calculated by spectral amplitude at the modulation frequency and noise level around the modulation frequency using fast Fourier transform. Although AMFR was clearly evoked only by a modulation frequency of 40 Hz in adults while awake, AMFRs at modulation frequencies of 80 and 100 Hz were detected during sleep, in addition to 40 Hz AMFR. In children, 40 Hz AMFR was difficult to detect, but response could be clearly detected at higher modulation rates, especially at modulation frequencies of 80 and 100 Hz, compared with response in adults during sleep. Modulation frequencies from 80 to 100 Hz would thus appear optimal for detecting AMFR during sleep in children.

Adult↗
PubMed1993

Intraductal papillary neoplasms of the pancreas: diagnosis by endoscopic pancreatic biopsy.

Intraductal papillary neoplasms of the pancreas (IPN) are rare tumors, distinct from other pancreatic duct cell carcinomas both in terms of papillary polyp formation in the main pancreatic duct and their favorable prognosis. In the present study, endoscopic pancreatic biopsy (EPB) under fluoroscopic control was employed in three cases of IPN to obtain a tissue diagnosis prior to surgery. There were no complications and all biopsy specimens were adequate for histopathological evaluation. In our experience, EPB is a simple, safe and effective method, yielding sufficient material for preoperative tissue diagnosis of pancreatic tumors, especially in the case of IPN.

Adenocarcinoma, Papillary↗
PubMed1993

[A new lupin alkaloid, (-)-leontalbinine N-oxide, in Sophora flavescens var. angustifolia seeds and its synthesis by biomimetic transformation from (+)-matrine N-oxide].

The possibility of the biomimetic transformation of (+)-matrine N-oxide, a main alkaloid in Sophora flavescens var. angustifolia, under various oxidative conditions was examined by the use of several metallic ions. When (+)-matrine N-oxide was warmed with FeSO4, or Fe(COOH)2 in MeOH-H2O at 40 degrees C, (-)-7, 11-didehydromatrine [(-)-leontalbinine], a minor alkaloid in the same plant, was obtained along with (+)-matrine. This selective formation of (-)-leontalbinine seems to be specific to the reaction of (+)-matrine N-oxide with ferrous reagents. In addition, the structure of the newly isolated minor lupin alkaloid from the seeds of S. flavescens. was determined as (-)-leontalbinine N-oxide from its spectral comparison with the authentic sample.

Alkaloids↗
PubMed1993

Sleep apnea and palatal myoclonus in a patient with neuro-Behçet syndrome.

A 50-year-old man with neuro-Behçet syndrome showed truncal imbalance, dementia, palatal myoclonus, snoring and rhythmic inspiration synchronized with palatal myoclonus. Magnetic resonance imaging showed hypertrophy of the bilateral inferior olivary nuclei with slight pontine atrophy. A polysomnographic recording disclosed sleep apnea during non-REM sleep: 6% central type, 46% mixed type, and 48% obstructive type. We speculate that lesions of the respiratory center or related structures in the brainstem resulted in sleep apnea and that laryngeal myoclonus also affected the apnea.

Behcet Syndrome↗
PubMed1993

EEG changes during mental calculation, reverse recitation and association exercises in patients with dementia of the Alzheimer type.

The cerebral functional impairment in dementia of the Alzheimer type (DAT) was a quantitatively assessed using easily repeatable electroencephalographic analysis. Waveform recognition was employed to analyze the EEG (electroencephalogram) changes displayed before and after tasks of mental calculation, reverse recitation and mental association. Marked decrements in the incidence of theta and alpha waves together with decrements of the average amplitude of alpha waves were noted in normal elderly subjects after mental calculation and reverse recitation. In the patients with DAT, mental association tasks evoked pronounced decrements in the average amplitude of theta waves, the average frequency of alpha waves, and both the average frequency and average amplitude of beta waves. These results indicate that analysis of EEG activity responses to mental tasks provides an objective assessment of dementia.

Aged↗
PubMed1993

An application of phase spectral analysis to amplitude-modulation following response.

A phase spectral analysis developed by Fridman (1982) was applied to the detection of amplitude-modulated frequency following response (AMFR) and its clinical usefulness was evaluated. A 1000 Hz sinusoidally amplitude-modulated tone with a modulation frequency of 40 Hz and a modulation depth of 90% was delivered to the right ear of 10 normal-hearing subjects. According to Fridman's technique, an ensemble of sweeps was divided into 10 groups and group averages were obtained. Then phase variances were calculated using fast Fourier transform for the group averages. In order to determine the optimal conditions of analysis for constructing an automatic detection program using phase spectral analysis, frequency spacing, number of sampling points and number of sweeps averaged per group were investigated. The sensitivity of phase spectral analysis for automatic detection of AMFR was also evaluated. The results suggested that the optimal number of sampling points and frequency spacing are 512 points and 4.9 Hz (observation window 204.8 ms), respectively. Concerning the average number of sweeps, the synchrony measure of the frequency component corresponding to the modulation frequency increased as the number of sweeps increased. Furthermore, it was demonstrated that threshold determination by phase spectral analysis is more sensitive than detection of the threshold by visual analysis of waveform configuration.

Adult↗
PubMed1993

[Clinical application of transiently evoked otoacoustic emissions in screening for auditory dysfunction].

Transiently evoked otoacoustic emissions (TEOAE) should be used clinically as an objective and noninvasive screening test for auditory dysfunction in children. The features of TEOAE measured by "ILO88" with non linear click stimuli are discussed. The following results were obtained: 1) The normal range of a power spectrum was determined using 42 adults with normal hearing and compared with data for sensorineural hearing disturbance. The power spectrum of TEOAE in adults with normal hearing sloped downward at high frequency and was the same for right and left ears in both males and females. For comparison with sensorineural hearing disturbance, a significant correlation between the audiogram and power spectrum of TEOAE was sought. 2) Patients with otitis media with effusion (109 ears in 67 children) were examined by audiometry, tympanometry and TEOAE. The hearing disturbance threshold of 45 cases with TEOAE was lower than that in cases with no TEOAE. In tympanometry, low intratympanic pressure was noted in the absence of TEOAE. 3) TEOAE and spontaneous otoacoustic emission were examined in 42 adults with normal hearing and 27 neonates using the same probe and level of stimuli to clarify differences in TEOAE according to age. The amplitude of TEOAE and the highest peak of the frequency component at 4kHz in neonates exceeded those of adults. The peak stimuli recorded with the intracanal probe in neonates was also larger than that of adults. Three out of 15 neonates had spontaneous otoacoustic emission and essentially the same proportion was noted in young adults.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Impedance Tests↗
PubMed1993

[Immunohistochemical studies on expression of epidermal growth factor receptor (EGFR) and proliferative activity in human colorectal cancers].

Expressions of epidermal growth factor receptor (EGFR) were studied immunohistochemically in a total of 101 human colorectal cancers, and compared with clinicopathological findings. DNA polymerase alpha, a marker of the proliferating cells, was stained immunohistochemically in 26 cases in which fresh and frozen sections were obtained, and growth fraction was calculated as labeling index. EGFR positive tumor cells were detected in 17 cases (16.8%) of the 101 colorectal cancers. Significantly high incidence of EGFR expression was observed in more deeply invasive tumors, larger tumor sizes and more infiltrating macroscopic types. No significant differences, however, were observed between EGFR-positive and EFGR-negative cases regarding lymphnode metastasis, histopathological classification and pathological staging. DNA polymerase alpha laveling index was 597.9 +/- 76.6, and 428.4 +/- 140.2 in EGFR-positive cases, and EGFR-negative cases, respectively. There was a significant (p < 0.01) correlation between DNA polymerase alpha labeling index and EGFR status. These results indicate that EGFR positive cases in colorectal cancers have higher proliferative activity and more invasive stage, compared with EGFR negative cases, and suggest that EGFR produced by tumor cells play an important role in the progression and proliferation of colorectal cancers.

Adenocarcinoma↗