Biomedical subjects

S Horiguchi

Publications and source records attributed to S Horiguchi.

At least 37 records · Page 2Linked to original sources

PubMed1997

[A case of pituitary apoplexy: remarkable improvement of visual acuity and field by surgical intervention at the subchronic stage].

A case is reported of a pituitary apoplexy which shows remarkable improvement of visual acuity and field by transsphenoidal surgery performed 33 days after hemorrhage. Possible factors contributing to this excellent surgical outcome are speculated about as follows; atrophic brain (wide suprasellar cistern), destruction of the sella floor by the tumor (infrasellar/extracranial decompression), no vasospasm (pure intracapsular hemorrhage), no hypopituitarism, less invasive operation (transsphenoidal surgery), and so on. Transsphenoidal surgery is thought to be worth performing for pituitary apoplexy, even if timing for the operation is later than the acute stage and even if initial visual impairment is severe.

Chronic Disease↗

PubMed1996

Toluene itself as the best urinary marker of toluene exposure.

Head-space gas chromatography (GC) and high-performance liquid chromatography (HPLC) (with fluorescence detectors) methods were developed for toluene (TOL-U) and o-cresol (CR-U) in urine, respectively. In order to identify the most sensitive urinary indicator of occupational exposure to toluene vapor (TOL-A) among TOL-U, CR-U, and hippuric acid in urine (HA-U), the two methods together with an HPLC (with untraviolet detectors) method for determination of HA-U were applied in the analysis of end-of-shift urine samples from 115 solvent-exposed workers (exposed to toluene at 4 ppm as geometric mean). Regression analysis showed that TOL-U correlated with TOL-A with a significantly higher correlation coefficient than did HA-U or CR-U. With regard to the TOL-A concentrations at which the exposed subjects could be separated from the nonexposed by the analyte, TOL-U achieved separation at < 10 ppm TOL-A, whereas both HA-U and CR-U did so only when TOL-A was 30 ppm or even higher. The ratio of the analyte concentrations at 50 ppm TOL-A to those at 0 ppm TOL-A was also highest for TOL-U. Overall, the results suggest that TOL-U is a better marker of exposure to toluene vapor than HA-U or CR-U.

Biomarkers↗

PubMed1996

Early diagnosis and stage classification of vocal cord abductor paralysis in patients with multiple system atrophy.

OBJECTIVES: Vocal cord abductor paralysis (VCAP) is a life threatening complication which may cause nocturnal sudden death in patients with multiple system atrophy. However, the early diagnosis of VCAP is often difficult to make on routine laryngoscopy performed during wakefulness, as stridor, which is the sole symptom of VCAP in the early stage, develops only during sleep. The aim was to investigate laryngeal dysfunction in patients with multiple system atrophy while awake and asleep. METHODS: Seven patients with multiple system atrophy with nocturnal stridor and five control patients were studied. Vocal cord movement was analysed by laryngoscopy while the patients were awake and also during sleep induced by intravenous diazepam. RESULTS: When awake, for the seven patients with multiple system atrophy normal movement of the vocal cords occurred in three, mild abduction restriction in three, and paradoxical movement in one. When asleep, however, all showed obvious paradoxical movement with high pitched inspiratory stridor. In controls, there were no differences in the vocal cord movement between wakefulness and sleep. From these findings, VCAP could be divided into four stages: stage 0 (normal) with normal vocal cord movement during both wakefulness and sleep, stage 1 (mild VCAP) with normal movement during wakefulness and paradoxical movement during sleep, stage 2 (moderately severe VCAP) with abduction restriction during wakefulness and paradoxical movement during sleep, and stage 3 (severe VCAP) with an almost midline position for the vocal cords during both wakefulness and sleep. CONCLUSIONS: Laryngoscopy during sleep can disclose subclinical VCAP, making an early diagnosis of VCAP in patients with multiple system atrophy. Stage 2 of VCAP seems to be a suitable stage for tracheostomy in patients with multiple system atrophy.

Aged↗

PubMed1996

The role of extracellular cations in the development of myogenic contraction in isolated rat small arteries.

The purpose of this study was to determine the roles of extracellular cations (Na+, Ca2+ and K+), membrane K+ channels and Na+/K+ ATPase in the development of myogenic contraction (transmural pressure-induced contraction) in isolated rat skeletal muscle and mesenteric small arteries. The vessels were pressurized under no-flow conditions in a tissue bath. Lumen diameter was measured with a videomicroscopic system. Myogenic contraction was evoked by increasing the lumen pressure from 40 to 100 mmHg. The vessels demonstrated myogenic contraction in low-Na+ (Na+ 1.18 mmol/L) physiological salt solution (PSS), and this was abolished by removing Ca2+ or by applying nifedipine or nisoldipine (10 mumol/L). Neither tetraethylammonium (TEA, 1 mmol/L), Ba2+ (10 mumol/L) nor glibenclamide (1 mumol/L) affected the magnitude of the myogenic contraction. K(+)-free PSS and ouabain (0.1 mmol/L) partially depressed myogenic contraction. In conclusion, myogenic contraction was triggered by a cellular process that requires extracellular Ca2+, but not Na+ or K+. This triggering process is not affected by TEA, Ba2+ or glibenclamide.

Animals↗

PubMed1995

Effects of methanol on styrene metabolism among workers occupationally exposed at low concentrations.

A survey was conducted in the second half of a work week on 39 male workers who were occupationally exposed to styrene in combination with methanol and methyl acetate during the production of plastic buttons. Time-weighted average exposure during an 8-h shift to styrene (Sty-A) and methyl acetate was monitored by carbon cloth-equipped personal samplers and to methanol by water-equipped ones. Urine samples were collected near the end of the shift and analyzed for mandelic (MA-U) and phenylglyoxylic acids (PhGA-U) by HPLC. Geometric mean styrene concentration was 12.4 ppm (micrograms/g) with the maximum of 46 ppm, whereas the values for methanol and methyl acetate in combination were 23.5 ppm and 229 ppm, respectively. The relationship of MA-U and PhGA-U with Sty-A was examined by linear regression analysis. The equations for the regression lines were compared with the results from a previous survey (Ikeda et al. 1983) in which workers were exposed only to styrene, and the methods employed were identical with that in the present study. The comparison showed no evidence to suggest that styrene metabolism is suppressed by coexposure to methanol and methyl acetate at low concentrations below the current occupational exposure limit of 200 ppm.

Acetates↗

PubMed1995

Urinary methylchloroform rather than urinary metabolites as an indicator of occupational exposure to methylchloroform.

In order to compare methylchloroform (MC, or 1,1,1-trichloroethane) per se and its metabolites in urine as indicators of occupational exposure to this solvent, 50 male solvent workers were studied in the second half of a working week to evaluate the exposure-excretion relationship. The time-weighted average intensity of solvent exposure of individuals during an 8-h shift was monitored by personal diffusive sampling. Urine samples were collected near the end of the shift and were analyzed for MC and its metabolites [i.e., trichloroacetic acid (TCA), trichloroethanol (TCE) and total trichloro-compounds (TTC; the sum of TCA and TCE)] by head-space gas chromatography. MC per se, TCA, TCE, and TTC in urine correlated significantly (P < 0.01) with MC in ambient air, and among the four the correlation coefficient was highest for MC. The same result were obtained by multiple regression analysis in which ambient air MC was taken as the dependent variable and either the three indicators urinary MC, TCA, and TCE or the two indicators urinary MC and TTC were taken as independent variables. Taking the specificity and selectivity of the analyte as well as the simple and hazardous chemical-free procedure of analysis into consideration, it is concluded that MC is the analyte of choice as an indicator of occupational exposure to MC, when urine is selected as a specimen available by noninvasive sampling.

Chemical Industry↗

PubMed1995

Vocal cord abductor paralysis (VCAP) in Parkinson's disease: difference from VCAP in multiple system atrophy.

Vocal cord abductor paralysis (VCAP) is rare in Parkinson's disease (PD), while it is frequent in multiple system atrophy (MSA). Although VCAP is a life-threatening complication it has not yet been clarified whether there is any difference in the mechanism of VCAP between PD and MSA. Examining 3 autopsy-proven PD patients who developed severe VCAP requiring tracheostomy, we found the following differences in the mechanism of VCAP between MSA and PD: (1) clinical and laryngofiberscopic examination showed that VCAP in PD was not exacerbated during sleep, unlike in MSA; (2) On histological examination of the intrinsic laryngeal muscles, the posterior cricoarytenoid muscle demonstrated no abnormalities in PD, while the muscle showed characteristic neurogenic atrophy in MSA. There seemed to be two types of VCAP, namely the nonparalytic type observed in PD, and the paralytic type observed in MSA. Severe dysphagia requiring tube-feeding was common among PD patients who presented with VCAP. Although the relationship between VCAP and dysphagia is unknown, one should be aware of the possibility of fatal VCAP in PD patients with severe dysphagia.

Aged↗

PubMed1995

Monitoring of exposure to methylpentanes by diffusive sampling and urine analysis for alcoholic metabolites.

OBJECTIVES: To investigate the possibilities of personal ambient monitoring and biological monitoring for methylpentane isomers. METHODS: The performance of activated carbon cloth to absorb 2- and 3-methylpentane was studied by experimental vapour exposure followed by solvent extraction and gas chromatography (GC). Urine from workers and rats exposed to 2- and 3-methylpentane was analysed by GC with or without acid or enzymatic hydrolysis. RESULTS: Carbon cloth absorbed 2- and 3-methylpentane linearly to exposures up to eight hours and to 400 ppm, and was sensitive enough to detect a 15 minute peak of exposure. The two isomers were clearly separated from hexane on a DB-1 column. For analysis of the urine, enzymatic hydrolysis was superior to acid hydrolysis. Exposure of rats to methylpentane vapours showed that 2-methyl-2-pentanol and 3-methyl-2-pentanol were excreted in urine in proportion to the dose of 2-methylpentane and 3-methylpentane, respectively. 2-Methyl derivatives of 1-, 3-, and 4-propanol, 2-methylpentane-2,4-diol, and 3-methyl-2-pentanol were minor metabolites. Analysis of urine from the exposed workers showed that 2-methyl- and 3-methyl-2-pentanol are leading urinary metabolites after exposure to the corresponding methylpentane. CONCLUSIONS: Diffusive sampling is applicable to monitor 2- and 3-methylpentane vapours as is the case for hexane vapour. 2-Methyl-2-pentanol and 3-methyl-2-pentanol will be markers of occupational exposure to 2-methylpentane and 3-methylpentane, respectively. Also, 2-methylpentane-2,4-diol might be a marker of exposure to 2-methylpentane.

Animals↗

PubMed1995

[Relationship between orthostatic dizziness and/or giddiness, and hypotension in young normal females--a survey of 301 subjects].

Orthostatic dysregulation (OD) generally implies a systemic condition indicating poor circulatory function resulting from autonomic imbalance. It frequently appears in younger individuals at or around puberty, and is predominant in females. It is also known that individuals with this condition experience orthostatic dizziness and/or giddiness, fainting on standing and other various non-specific, subjective symptoms. Three hundred and one young normal females ranging in age from 18 to 21 years were examined using the Schellong test and the OD questionnaire to investigate the relationship between orthostatic dizziness and hypotension. Orthostatic dizziness and/or giddiness was the most frequent symptom, noted in 171 of 301 young subjects (56.8%), regardless of whether or not the subjects were actually diagnosed as having OD based on the questionnaire. Both low systolic blood pressure (90 mmHg or loss) in the supine position and systolic pressure decrease (11 mmHg or more) in the standing position during the procedure for the Schellong test were significantly related to the occurrence of orthostatic dizziness and/or giddiness. It may be reasonable to conclude from the present study that orthostatic dizziness is even more commonly observed in young normal female subjects than expected and correlates more closely with both hypotension and systolic pressure decrease in the standing position than previously thought. Thus, in our opinion, this testing procedure introduced by Schellong can be useful, and is clinically applicable to the assessment of orthostatic dizziness and/or giddiness and OD, since this test has the advantage of being simple enough to carry out in clinical practice.

Adolescent↗

PubMed1995

Excessive level of parathyroid hormone may induce the reduction of recombinant human erythropoietin effect on renal anemia.

We examined the effect of total parathyroidectomy (PTX) on renal anemia in 20 dialysis patients with secondary hyperparathyroidism. We obtained the following results. (1) Before PTX, 13 of these patients were not treated with erythropoietin (EPO) while the remaining 7 patients received EPO therapy. (2) In 8 out of 13 cases without recombinant human EPO treatment before PTX, a 10% increase in RBC was observed after PTX. (3) In 7 of the patients who were treated with EPO before PTX, anemia was improved after PTX despite discontinuation of EPO therapy in 2, a reduced dose of EPO in 3 and the same dose of EPO in 2. Our data is consistent with the notion that elevated blood levels of PTH in patients with chronic renal failure participate in the genesis of anemia of renal failure.

Adult↗

PubMed1995

[High-resolution teleradiology system based on ISDN and small computer].

A high-speed, high-resolution teleradiology system based on the Integrated Services Digital Network (ISDN) is described. The LAN at Saku Central Hospital and the Radiological Department at Shinshu University Hospital (60 km) are interfaced to a Macintosh computer with an image digitizer, interactive display, and network interface. The transmission time for a digitized high-resolution radiographic image with 4.39 megabytes was 358 seconds using a 128 kbps (kilobit-per-second) channel (B1 + B2), and the mean transmission rate was 98.1 kbps. Teleradiology conference is also available using this system. Radiologists can observe the same high-resolution images on the CRT screen simultaneously at two different remote hospitals, indicating a point of interest on the image by means of a mouse cursor. Graphical data of interest to the radiologists are also transmitted and displayed on the CRT.

Computer Communication Networks↗

PubMed1994

Toluene in blood as a marker of choice for low-level exposure to toluene.

The validity of two new biological exposure markers of toluene in blood (TOL-B) and toluene in urine (TOL-U) was examined in comparison with that of the traditional marker of hippuric acid in urine (HA-U) in 294 male workers exposed to toluene in workroom air (TOL-A), mostly at low levels. The exposure was such that the geometric mean for toluene was 2.3 ppm with a maximum of 132 ppm; the workers were also exposed to other solvents such as hexane, ethyl acetate, styrene, and methanol, but at lower levels. The chance of cutaneous absorption was remote. Higher correlation with TOL-A and better sensitivity in separating the exposed workers from the nonexposed subjects were taken as selection criteria. When workers exposed to TOL-A at lower concentrations (< 50 ppm, < 10 ppm, < 2 ppm, etc.) were selected with correlation with TOL-A was examined, TOL-B showed the largest correlation coefficient which was significant even at TOL-A of < 1 ppm, whereas correlation of HA-U was no longer significant when TOL-A was < 10 ppm. TOL-U was between the two extremes. The sensitivities of TOL-B and TOL-U were comparable; HA-U showed the lowest sensitivity. Thus, it was concluded that TOL-B is the indicator of choice for detecting toluene exposure at low levels.

Hippurates↗

PubMed1994

Laryngeal electromyography with separated surface electrodes in patients with multiple system atrophy presenting with vocal cord paralysis.

When recording the activity of the posterior cricoarytenoid muscle (PCA) with surface electrodes, there is contamination from the surrounding muscles such as the cricopharyngeal muscle. We therefore devised a new oesophageal catheter electrode of the separate type, having three individual surface electrodes for the PCA, cricopharyngeal muscle and diaphragm. The records obtained with this catheter demonstrated satisfactory separation between PCA and cricopharyngeal muscle activities. We used this catheter in patients with multiple system atrophy presenting with vocal cord paralysis, who were awake or asleep. There were two interesting electromyographical findings, which were inspiratory activity of the adductor muscle (the thyroarytenoid muscle) and fade-out of the abductor muscle, that is, PCA activity during sleep. Although vocal cord paralysis is one of the most serious life-threatening complications, the precise mechanism has not been clarified. We believe that our catheter may be useful in investigating the mechanism of vocal cord paralysis which could cause sudden death in neurodegenerative disorders, including multiple system atrophy.

Aged↗

PubMed1994

Effects of ryanodine on development of myogenic response in rat small skeletal muscle arteries.

OBJECTIVE: The aim was to elucidate the functional role of the sarcoplasmic reticulum in myogenic contraction. METHODS: Small arteries which perfuse the rat gracilis muscle were isolated and cannulated. The inner diameter was measured under no flow condition. Myogenic contraction was induced by increasing transmural pressure from 40 to 100 mm Hg. The diameter transient and the steady state internal diameter were analysed at 40 (ID40) and 100 mm Hg (ID100) of lumen pressure. RESULTS: In control, the vessels dilated immediately after the pressure change, and then constricted over approximately 4 min (the diameter decay). ID40 and ID100 were 120(SEM 16) and 108(12) microns (n = 6, p < 0.05), respectively. Ryanodine (10(-5) M) decreased ID40 to 82(8) microns. The relative rate of the diameter decay in the first 1 min was lower in the ryanodine treated vessels than in control, at 43(1)% v 74(7)%, n = 6 (p < 0.05). While KCl constriction was similar to that of ryanodine, the diameter decay was identical to that of control. Thus a decrease in baseline diameter was not of itself the cause of the depressed rate of diameter decay in the ryanodine treated vessels. Nisoldipine (10(-6) M) abolished myogenic contraction. CONCLUSIONS: Ryanodine sensitive sarcoplasmic reticular function is probably involved in the mechanism for developing the myogenic response in rat skeletal muscle small arteries.

Animals↗

PubMed1994

Improvement of urinary delta-aminolevulinic acid determination by HPLC and fluorescence detection using condensing reaction with acetylacetone and formaldehyde.

We improved the method for determining urinary delta-aminolevulinic acid (ALA) by HPLC-fluorometer after pre-column derivatization with acetylacetone and formaldehyde, and a stable ALA derivative was obtained without any effect from various urinary components as demonstrated by the complete recovery of ALA (100.9 +/- 5.5%, n = 85) from the urine samples. The modified procedure was as follows: Twenty microliters of urine sample, 5 ml of acetylacetone solution (acetylacetone/ethanol/distilled water containing 4 milligrams of NaCl; 15/10/75), and 0.45 ml of 9.3% formaldehyde solution were mixed and boiled for 15 min. The fluorescent derivative of ALA was separated and analyzed by HPLC with the fluorometer at Ex 246 nm and Em 458 nm. Using a gradient program, the retention time of the ALA derivative was 7.3 min and the analysis could be repeated at 13 min intervals. Concentrations of ALA in urine samples measured by this method were significantly correlated with those measured by the Mauzerall-Granick (M-G) method (n = 85, r = 0.993, p < 0.001). The values obtained by our method were, however, lower than those obtained by the M-G method. Urinary ALA concentrations of 40 non-lead workers ranged from 0.1 to 2.3 mg/g creatinine with the mean +/- SD of 1.1 +/- 0.4 mg/g creatinine as measured by the present method.

Adult↗

PubMed1994

Fractional clearances of low molecular weight proteins in lead workers.

Urinary alpha 1-microglobulin (alpha 1-m) and beta 2-microglobulin (beta 2-m) can be used as early indicators of renal tubular dysfunction. However, low levels of lead exposure cause an increase in urinary alpha 1-m, but not in urinary beta 2-m. In order to clarify the level of tubular dysfunction in early lead nephropathy, fractional clearances of alpha 1-m (FC-alpha 1-m) and beta 2-m (FC-beta 2-m), i.e., the ratios of these clearances to the creatinine clearance, were measured in 99 male lead workers. Blood urea nitrogen, serum creatinine, uric acid, and urinary creatinine and N-acetyl-beta-D-glucosaminidase activity were also measured to diagnose the presence of other renal dysfunction. The median of FC-alpha 1-m was 0.13% in the control group. The FC-alpha 1-m increased in lead workers with blood lead (B-Pb) levels above 20 micrograms/dl. The correlation of FC-alpha 1-m with urinary alpha 1-m was highly significant, but there was no correlation with serum alpha 1-m. The median of FC-beta 2-m was 0.065% in the control group. There was a correlation of FC-beta 2-m with FC-alpha 1-m, but there was no correlation with B-Pb, or with serum beta 2-m. These results suggest the following: There was a very low excretion rate of alpha 1-m and beta 2-m in both the control group and the lead exposed groups. The excretion rate of alpha 1-m was higher than that of beta 2-m.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Turn-over of PAF in cultures of human paranasal sinus mucosa.

The change of PAF concentration in the culture medium was investigated by radioimmunoassay when 10(-8) M PAF or 10(-8) M lyso-PAF was incubated with a piece of normal human paranasal sinus mucosa. The PAF concentration in the medium of the former group was halved within 11.3 min and reduced to less than 5% of the initial concentration within 60 min. However, there was no significant difference in the reduction of PAF concentrations in the medium between groups with or without the mucosa. When 10(-8) M lyso-PAF was incubated with a piece of mucosa, PAF gradually increased and reached the maximum of 0.36 x 10(-8) M at 20 min, and thereafter quickly decreased to a non-detectable level.

Cells, Cultured↗

PubMed1993

[Image-transmission of radiotherapy planning using 64kbps-ISDN videophone].

We carried out the image-transmission using the 64kbps-ISDN and two terminals of the videophone installed in Osaka Teishin Hospital and Department of Radiation Oncology, Biomedical Research Center, Osaka University Medical School. The frame speeds (sec./frame) of the videophone are 1.2 for standard resolution with 320 x 200 matrix and 5.0 for high resolution with 640 x 400 matrix. Although the image with 640 x 400 matrix is not enough for the radiation diagnosis such as the chest radiogram, the image is useful for the radiation therapy planning. This system is easy to operate, and will be widely distributed in near future.

Computer Communication Networks↗