Fumihiro Sata

Autonomic neurotoxicity of alcohol assessed by heart rate variability

Measurement of heart rate variability (CVR-R) provides a promising approach for evaluation of the autonomic nervous function. Specifically, high- and low-frequency component coefficients of variation of the CVR-R (C-CVHF and C-CVLF), computed from component spectral powers by autoregressive spectral and component analyses, are inferred to reflect parasympathetic and sympathetic activities, respectively. To assess the acute and chronic effects of alcohol on parasympathetic and sympathetic activities, ECGs in the supine posture were obtained in 11 male healthy volunteers, and in 23 male patients with severe alcoholic dependency together with the same number of age-matched healthy men. Significant changes in the CVR-R and heart rate were found 1 h after ethanol intake in the volunteers; also, the 1-h alteration in heart rate after intake was inversely correlated with that in the C-CVHF. The CVR-R, C-CVHF and C-CVLF were significantly depressed in the alcoholics compared to the matched controls. In the alcoholics, the age-adjusted correlation coefficients between not only the CVR-R but also C-CVHF and heart rate were negatively significant. These data suggest that acute and habitual intake of alcohol affects cardiac autonomic functions including sympathetic and parasympathetic activities; and, increase of heart rate in relation to alcohol, at least in alcoholics, seems to occur through reducing the parasympathetic activity.

Adjustment for urinary flow rate: an improved approach to biological monitoring

SummaryThe use of urinary monitoring in medical surveillance programs in industry requires the development of an accurate and unbiased index of urinary concentrations of occupational toxins. To examine the effects of urinary flow rate on adjusted and non-adjusted urinary excretion of 11 heavy metals and organic substances, 19 metal-foundry workers were studied during four time periods of the day under conditions of water restriction and loading. The results indicate that urinary flow rate significantly affects not only the non-adjusted urinary concentration for all substances, but also affects timed excretion as well as concentrations adjusted to urinary specific gravity and to urinary creatinine during any time period of the day. On the other hand, the concentration adjusted to urinary flow rate (UF-adjusted concentration) is independent by definition of urinary flow; therefore, this adjustment is applicable for highly diluted and highly concentrated urine samples without repetition of urine collection. It is concluded that UF-adjusted concentration is a useful index for the measurement of most urinary substances, while adjustments to urinary specific gravity and to urinary creatinine concentration have only limited utility in evaluating toxin levels in spot urine samples.

Adjustment of creatinine-adjusted values in urine to urinary flow rate: a study of eleven heavy metals and organic substances

The use of urinary monitoring in medical surveillance programs in industry requires development of an accurate and unbiased index of urinary concentrations of occupational toxins. To examine the effects of urinary flow (UF) rate on the standard creatinine (Cn)-adjusted value and the UF- and Cn-adjusted values according to Greenberg and Levine and to Araki et al. for 11 heavy metals and organic substances, 19 metal-foundry workers aged 34–59 years (mean 48), who had been exposed to lead, zinc, and copper for 2–17 (mean 10) years, were studied during four periods of the day under water-free, water-restrictive and water-loading conditions for 6 days. The blood lead concentrations of the 19 workers ranged from 22 to 59 (mean 38) μg/dl. The results indicated that there was no significant OF effect on the UF- and Cn-adjusted values of Araki et al. for all urinary substances except mercury and coproporphyrin. On the other hand, the UF- and Cn-adjusted value of Greenberg and Levine was positively correlated with OF rate for all urinary substances, and the standard Cn-adjusted value was either positively or inversely correlated with OF rate for many urinary substances. Therefore, the UF- and Cn-adjusted value of Araki et al. is considered to be applicable to the measurement of most urinary substances under conditions of wide variation in OF rate.

Immunological effects of CaEDTA injection: Observations in two lead workers

To evaluate the effects of calcium disodium ethylenediamine tetraacetate (CaEDTA) injection on human immune system in relation to exposure to lead, we administered CaEDTA by intravenous injection for 1 hr three times (three consecutive days) a week to two male lead workers. They had been engaged in recycling lead for 31 and 22 years, aged 61 and 53 years (workers 1 and 2), respectively. Before the treatment of CaEDTA, their blood lead concentrations (PbB) were 81 and 68 micrograms/dl, respectively. The administration of CaEDTA had been carried out to worker 1 for 10 weeks and to worker 2 for 6 weeks. A significant decrease in PbB between before and after three-times CaEDTA injection was found in both workers. Significant increases in IgG, IgA, IgM, CD8+, and CD57+ cells were found in worker 1. A significant increase in IgD was found in worker 2. During the study period, IgG in worker 1 and CD4+ cells in worker 2 were gradually increasing. There was a significant negative correlation between IgG and PbB in worker 1. It is suggested that the immunological function such as antibody formation in lead workers might be improved by CaEDTA injection.

Are Faster or Slower Large Myelinated Nerve Fibers More Sensitive to Chronic Lead Exposure? A Study of the Distribution of Conduction Velocities1

To determine which of the faster and slower large myelinated nerve fibers (alpha fiber group) are more sensitive to chronic lead exposure, the distribution of nerve conduction velocities (DCV) as well as conventional sensory nerve conduction velocity (SCV) were measured once a month for 20 and 11 months in two male lead workers with blood lead concentrations of 70 to 121 and of 63 to 85 μg/dl, respectively. Differences in the frequency beyond the “normal” ranges between conduction velocities of faster nerve fibers (V80, V90, or SCV) and those of slower fibers (V10 or V20) were analyzed by the McNemar test. In the two lead workers, the values below the lower normal limits for the V80 and V90 velocities were more frequent than those for the V10 and V20 velocities; similarly, lower values for the SCV were more frequent than those for the V10 and V20 velocities (P < 0.05). It was suggested that faster nerve fibers are more sensitive to chronic lead exposure than slower nerve fibers. These findings agree with our published data on the effects of local vibration, thallium, n-hexane, styrene, mixed organic solvents, alcohol dependency, and diabetes mellitus.