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.

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.

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.

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.

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)

Biological monitoring and possible health effects in workers occupationally exposed to methyl methacrylate

Monitoring by means of blood and urine analysis for methanol was successfully applied in 32 male workers who were exposed to methyl methacrylate (MMA) monomer at 6 ppm as a geometric mean and at 112 ppm as the maximum. Measurement of time-weighted average (TWA) intensity of the vapor exposure was successfully conducted with a diffusive sampler with activated carbon cloth as an adsorbent. Methanol concentrations in whole blood, serum, and urine samples were measured by headspace gas chromatography. The methanol concentrations in the three biological samples collected at the end of 8-h workshifts related linearly with the TWA MMA vapor concentrations, with correlation coefficients of 0.8-0.9. Quantitative evaluation of MMA in vapor and of methanol in urine suggests that only 1.5% of MMA inhaled will be excreted in urine as methanol. There were no significant clinical symptoms or abnormal hematological or serum biochemical findings at this exposure level, except that some workers complained throat irritation and frequent cough and sputa. The results indicate that biological monitoring by analysis for methanol is sensitive enough to detect MMA exposure at levels at which no serious health effects are to be expected.

Modification of myogenic intrinsic tone and [Ca2+]i of rat isolated arterioles by ryanodine and cyclopiazonic acid

The role of the sarcoplasmic reticulum (SR) in regulating myogenic tone and [Ca2+]i was examined with ryanodine and cyclopiazonic acid (CPA) in the rat skeletal muscle arteriole (A(sk)) and mesenteric arteriole (Ams). Arterioles were cannulated at both ends to control luminal pressure in a tissue bath. Luminal diameter was measured with a video-monitored microscopic system. Fura 2-AM was loaded to measure [Ca2+]i using the fluorescence intensity ratio at excitation wavelengths of 340 to 380 nm (F340/380). The myogenic response (luminal pressure was increased from 40 to 100 mm Hg) and the intrinsic tone at 40 mm Hg were observed in A(sk) but not in Ams. Ryanodine (10(-5) M decreased the steady-state diameter of A(sk) from 138 +/- 8 to 85 +/- 9 microns (P < .05) and increased the F340/380 ratio; these effects were reversed by nifedipine or Ca(2+)-free solution. Ryanodine shifted the [Ca2+]o-contraction response curve upward. CPA (10(-5) M) also decreased the steady-state diameter of A(sk) from 131 +/- 7 to 98 +/- 11 microns (P < .05). In contrast, Ams responded to neither ryanodine nor CPA. Caffeine-induced contractions were significantly reduced by either ryanodine or CPA in both arterioles. These results indicate that SR dysfunction increased the susceptibility of the arteriolar tone to [Ca2+]o and enhanced the tone of A(sk). In conclusion, the SR function may play a critical role in regulating [Ca2+]i and the intrinsic tone of A(sk) that was myogenically active at physiological luminal pressure.

Exposure-excretion relationship of styrene and acetone in factory workers: a comparison of a lipophilic solvent and a hydrophilic solvent

A factory survey was conducted in the second half of a working week on 41 exposed male workers, who were engaged in fiber-reinforced plastics work and exposed to the mixed vapors of styrene and acetone. Nonexposed workers, 20 men, were recruited from the same factory. Styrene and acetone in respiratory zone air were monitored for a 8-h shift with carbon cloth- and water-equipped personal diffusive samplers, respectively. Blood and urine samples were collected at the shift-end. Acetone and styrene concentrations in whole blood, serum and urine were measured by head-space gas chromatography, and phenylglyoxylic acid in urine by high-performance liquid chromatography. All biological exposure indicators analyzed correlated significantly with the intensity of exposure to the corresponding solvent during the shift. The slopes of the regression lines indicate that a very small fraction of styrene absorbed will be excreted into urine as styrene per se, and that styrene is quite effectively excreted into urine after metabolic conversion. In contrast, the slopes of regression lines for acetone suggest that acetone distributes both in the blood and urine quite evenly. When the distribution of the solvent in serum was compared with that in the whole blood, it was found that almost all of styrene in blood is present in the serum, whereas acetone distributed very evenly in the cellular and noncellular fractions of the blood.

[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.

Comparative evaluation of blood and urine analysis as a tool for biological monitoring of n-hexane and toluene

Blood and urine samples were collected from 57 male Japanese solvent workers [exposed to n-hexane (Hex-A), ethyl acetate, and toluene (Tol-A) at 1.5, 2.3, and 2.3 ppm as GM-TWA, respectively] and also from 20 male nonexposed workers at the end of a 8-h shift, and analyzed for n-hexane (Hex-B) and toluene (Tol-B) in blood, and n-hexane (Hex-U), toluene (Tol-U), 2,5-hexanedione [both with (HD-U/cHYD) and without hydrolysis (HD-U/sHYD)] and hippuric acid (HA-U) in urine. Regression analysis showed that both Hex-B and Tol-B correlated significantly with corresponding exposure to the solvents. Solvents in urine (Hex-U and Tol-U) also correlated with solvents in air but with smaller correlation coefficients than the solvents in blood. Both HD-U/cHYD and HD-U/sHYD showed significant correlation with Hex-A, but HA-U failed to do so with Tol-A. Based on the correlation among biological exposure indicators and solvent concentration in air, sensitivity as an exposure indicator was compared between the solvent in blood and the metabolite in urine in terms of the lowest solvent concentration at which the exposed can be separated (with statistical significance) from the nonexposed (the lowest separation concentration; LSC). The LSC was 3.9 ppm for Hex-B, 1 to 2 ppm for HD-U/sHYD and 10 to 30 ppm for HD-U/cHYD, suggesting that HD-U/sHYD is superior even to Hex-B in detecting low n-hexane exposure; this high sensitivity of HD-U/sHYD is due to the absence of HD-U/sHYD in the urine from the nonexposed.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal lesions induced in F344/DuCrj rats by 4-weeks oral administration of dimethylarsinic acid

The nephrotoxicity of dimethylarsinic acid (cacodylic acid, DMA) was examined in male and female F344/DuCrj rats. DMA administered perorally at doses of 113, 85, and 57 mg/kg for 4 weeks produced dose-related decreases in body weight and survival rate in both sexes. Mortality was higher and appeared more quickly in females than in males. Histopathological findings in the kidney were proximal tubular degeneration and necrosis, as well as papillary necrosis, and hyperplasia of the epithelium covering the papillae. Since extensive proximal tubular necrosis was observed only in dead animals of both sexes, and not in survivors or the controls, it was therefore concluded that the main cause of death could be attributed to nephrotoxicity of DMA. The results thus show that DMA is nephrotoxic to both male and female rats.

Urinalysis vs. blood analysis, as a tool for biological monitoring of solvent exposure

Blood and urine samples were collected at the end of an 8-h workshift from 30 male workers exposed to a mixture of n-hexane, ethyl acetate and toluene (each being about 2 ppm as geometric means) and also from 20 nonexposed male workers. Blood samples were analyzed for n-hexane and toluene, and urine samples were analyzed for n-hexane, toluene, 2,5-hexanedione (both with and without hydrolysis) and hippuric acid. Based on the correlation between biological exposure indicators and solvent concentrations in air, sensitivity as an exposure indicator was compared between solvents in blood and solvents or metabolites in urine in terms of the lowest solvent concentration at which the exposed subjects can be statistically separated from the nonexposed. Both n-hexane and toluene in blood were sensitive enough to detect the exposure at 6.1 ppm and 1.4 ppm, respectively. n-Hexane exposure below 2 ppm was detectable also by urinalysis for 2,5-hexadione without hydrolysis. Urinary hippuric acid, however, failed to detect low toluene exposure under the conditions studied. Of additional interest is the fact that toluene in urine correlated significantly with toluene in air, which apparently deserves further study for confirmation.

Formic acid excretion in comparison with methanol excretion in urine of workers occupationally exposed to methanol

A semiautomated head-space gas chromatographic (GC) method was developed for measuring formic acid in urine. The method consists of heating 1 ml urine sample in a 20-ml air-tight vial in the presence of 1 ml sulfuric acid and 2 ml ethanol at 60 degrees C for 30 min for ethyl esterification and air-liquid equilibrium, followed by automatic injection of 1 ml head-space air into a flame ionization detector GC. The detection limit was 1 mg/l for formic acid. The method was applied to measure formic acid in the shift-end urine samples from 88 workers exposed to methanol at 66.6 ppm (as geometric mean) and in urine samples from 149 nonexposed controls. Methanol concentrations were also determined. Regression analysis showed that urinary formic acid concentrations, as observed or corrected for either creatinine concentration or specific gravity of urine (1.016), correlated significantly with time-weighted average intensities of exposure to methanol vapor. Men excreted significantly more formic acid than women. Comparison with methanol excretion suggested, however, that urinary formic acid is less sensitive than urinary methanol as an indicator of methanol vapor exposure, primarily because the background level for formic acid (26 mg/l as arithmetic mean, or 23 mg/l as geometric mean) is more than ten times higher than the level for methanol (1.9 mg/l as arithmetic mean, or 1.7 mg/l as geometric mean). After theoretical methanol exposure at infinite concentration, the urinary formic acid/methanol ratio should be about 0.4.

Serum immunoglobulin and complement C3 levels in workers exposed to lead

Serum immunoglobulin and complement C3 levels were measured in workers exposed to lead at a secondary lead refinery and a solder factory. In the first survey, significant correlations were found between blood lead and IgA with a correlation coefficient of 0.296, and between blood lead and IgE with a correlation coefficient of 0.314. No other significant correlations were found among the indicators of lead exposure and humoral immunity. In the second survey, no significant correlations were found between blood lead and IgG and IgA. A significantly higher number of subjects with IgE of more than 400 IU/ml was found in the group with blood lead of more than 60 micrograms/100 g.

Comparative evaluation of urinalysis and blood analysis as means of detecting exposure to organic solvents at low concentrations

One hundred and forty-three workers exposed to one or more of toluene, xylene, ethylbenzene, styrene, n-hexane, and methanol at sub-occupational exposure limits were examined for the time-weighted average intensity of exposure by diffusive sampling, and for biological exposure indicators by means of analysis of shift-end blood for the solvent and analysis of shift-end urine for the corresponding metabolite(s). Urinalysis was also performed in 20 nonexposed control men to establish the "background level." Both solvent concentrations in blood and metabolite concentrations in urine correlated significantly with solvent concentrations in air. Comparison of blood analysis and urinalysis as regards sensitivity in identifying low solvent exposure showed that blood analysis is generally superior to urinalysis. It was also noted that estimation of exposure intensity on an individual basis is scarcely possible even with blood analysis. Solvent concentration in whole blood was the same as that in serum in the case of the aromatics, except for styrene. It was higher in blood than in serum in the case of n-hexane, and lower in the cases of styrene and methanol.

[A case of progressive supranuclear palsy presenting mouth opening difficulty with tonic contraction of the orbicularis oris muscle]

A 72-year-old man developed supranuclear ophthalmoplegia, bradykinesia, rigidity, unsteady gait, dementia, dysphagia, retrocollis, grasp reflex and apraxia of eyelid opening. These findings were compatible with progressive supranuclear palsy (PSP). At the age of 66, he presented a peculiar phenomenon characterized by simultaneous tonic contraction of the orbicularis oris muscle (OOM) and the palatal muscles elicited by pronouncing "pa", which resulted in difficulty of voluntary opening of the mouth and the rhinopharynx. Therefore, the respiration air reciprocated between the lung and the closed mouth. The expiratory pressure puffed out the cheeks, while the lips remained tightly closed. While the respiratory movements and the pressure increased by degree, the OOM contracted more strongly in proportion to the pressure. Sixty to ninety seconds after the elicitation, the pressure overcame the contraction of the OOM and the course of the phenomenon was completed. The electromyograms showed that the OOM activity was prolonged after initial voluntary contraction, remaining thus after a tracheostomy for pneumonia at the age of 72, and that it increased in response to the pressure. Apraxia of eyelid opening, one of the other symptoms, resembled this phenomenon in terms of the aspect of difficulty of voluntary mouth opening. The "holding" phase of grasp reflex, yet another symptom, resembled it in the recruitment of the OOM activity. The phenomenon is not common in patients with PSP. However, we concluded that it may be included among the symptoms of PSP because it has similar characteristics to apraxia of eyelid opening and grasp reflex, which are not uncommon in patients with PSP.

[The inhibitory effects of platelet activating factor (PAF) on ciliary activity of human paranasal sinus mucosa]

The effect of platelet activating factor (PAF) on human paranasal ciliated cells was investigated in vitro. Normal human paranasal sinus mucosa was obtained by surgical procedure and incubated with Eagle's MEM containing 10% FCS in the form of tissue culture. Ciliary activity was viewed at 37 degrees C under an inverted microscope equipped with a thermoregulator and a humidified CO2 chamber, recorded on video tapes and photoelectrically measured. Ciliary inhibition was observed by the treatment with PAF, in a dose dependent manner, at concentrations from 10(-10) M to 10(-6) M. The inhibitory effect of 10(-8) M PAF on ciliary activity was completely blocked when the mucosa was treated with 10(-6) M CV-3988 or 10(-6) M CV-6209 (specific PAF receptor antagonists). By the radioimmunoassay, the concentration of PAF in tissue culture was reduced by half within 12.5 min, and within 60 min it was only 5% of the initial concentration. There was no significant difference in ciliary inhibition between irrigation after a 60 min incubation with 10(-8) M PAF and non-irrigation. These results indicate that PAF inhibited ciliary activity directly and specifically, and induced irreversible damage primarily within the first 60 min after the challenge.

In vitro hydrolysis of methyl acetate, a limitation in application of head-space gas-chromatography in biological monitoring of exposure

Stoichiometric conversion of methyl acetate to methanol in vitro was detected when methyl acetate was incubated with blood for 2 to 8 h. The velocity of the reaction was so fast that almost all of methyl acetate disappeared in 8 h. The methanol formation was further confirmed by means of gas-chromatography-mass spectrometry. The capacity to hydrolyze methyl acetate was evenly distributed in cellular and noncellular fractions of blood, but not in urine. The significance of the observation is discussed in relation to biological monitoring of exposure to industrial ester solvents by means of head-space gas-chromatography of blood samples.

Curvi-linear relation between acetone in breathing zone air and acetone in urine among workers exposed to acetone vapor

An occupational health study was conducted on 45 acetone-exposed male workers in combination with 343 non-exposed men to examine the quantitative relationship between the intensity of acetone vapor exposure and the concentration of acetone in urine. The time-weighted average acetone concentrations were measured by means of diffusive samplers with water as absorbent, whereas urine samples were collected at the end of the shift as well as before the shift on the next morning. Acetone concentration in shift-end urine did not increase when the workers were exposed to acetone up to approx. 15 ppm, and this was followed by a gradual increase at a higher atmospheric acetone concentration, in a manner dependent to acetone vapor concentration. The comparison in acetone concentrations between the urine samples collected at the shift-end and those before the shift of the next morning showed that the levels in two sets of samples were the same among those exposed to 15 or less ppm acetone, whereas acetone in the shift-end samples was significantly higher than the counterpart levels in the pre-shift samples among those exposed to acetone at more than 15 ppm.

Monitoring of workers exposed to a mixture of toluene, styrene and methanol vapours by means of diffusive air sampling, blood analysis and urinalysis

Exposure of 34 male workers to combined toluene, styrene and methanol was monitored by personal diffusive sampling of solvent vapours in breathing zone air, analysis of shift-end blood for the 3 solvents and analysis of shift-end urine for hippuric, mandelic and phenylglyoxylic acids and methanol. The exposure of most of the workers was below current occupational exposure limits. Regression analysis showed that a linear correlation exists for each of the 3 solvents between any pairs of the concentrations in air, blood and urine. Namely, toluene, styrene and methanol concentrations in blood obtained at the end of a shift are linearly related to the time-weighted average intensity of exposure to corresponding solvents, and also hippuric, mandelic and phenylglyoxylic acids as well as methanol in shift-end urine. The concentrations of hippuric, mandelic and phenylglyoxylic acids as well as methanol in urine correlated with the respiratory exposure intensity. Comparison of the present results with the exposure--excretion relationship after occupational exposure to the individual solvent showed that no modification in metabolism is induced by the combined exposure when exposure is low, as in the present case.

[Mechanisms of hypoalgesia induced by intracisternal administration of PGD2 or PGE2]

Intracisternal administration of PGD2 (5 micrograms) and PGE2 (5 micrograms) induced hypoalgesia in conscious mice in acetic acid writhing test. The hypoalgesia caused by PGD2 was blocked by para-chlorophenylalanine, cyproheptadine or phenoxybenzamine. However, the suppression of writhing responses caused by PGE2 was not blocked at all by these drugs. These results indicate that the actions of PGD2 depend upon serotonin and norepinephrine systems.