Measurement of hand tremor induced by industrial exposure to metallic mercury.

Hand tremor due to industrial exposure to metallic mercury vapour was recorded in 26 exposed and 25 non-exposed male workers by an accelerometer attached to the dorsum of the hand. The subjects were instructed to hold the hand and the forearm in the same position first without and then with a load of 1250 g supported by the hand. Analysis of the records showed that the highest peak frequencies (HPF) (the frequency corresponding to the highest acceleration) were higher in the exposed men than in the controls and were related to the duration of exposure to mercury and to age. The changes in HPF between rest and load were again higher in the exposed men than in the controls and again related to the duration of exposure and to age. The second moment (M2) (an index taking into account the whole recorded spectrum) was similar in the exposed men and controls at rest. The changes in M2 between rest and load were higher in the exposed men than in the controls but were related to duration of exposure and to the biological measurements (loge of mercury in urine or blood) and not to age. These neurophysiological impairments might result from the tendency of metallic mercury to accumulate in the cerebellum and the basal ganglia. These results are consistent with the hypothesis that metallic mercury, even at concentrations probably below the current TLV-TWA of 0.05 mg/m3, can lead to neurological disorders.

Absences attributed to respiratory diseases in welders.

Certified sickness rates of 36 male welders were examined for the period 1970-9. They were compared with 36 male controls from the same petrochemical plant, matched for age, smoking habits, duration of employment, and social class. Indices of severity (average annual duration), duration (average length of spell), and frequency (inception rate of spells and inception rate per worker) were calculated. Absences for all diseases were similar, but absences attributed to respiratory diseases were slightly higher in welders in severity, duration, and frequency. The proportion of days lost attributed to respiratory diseases was 2.3 times higher in welders compared with controls. This was due to a large increase in absences attributed to lower respiratory tract diseases, the ratio of welders to controls being more than four to one for both severity and inception rate of spells. The comparison between welders and controls in smokers and non-smokers confirms other studies which show that smokers tend to be more affected by welding fumes than non-smokers.

Immersion and venous occlusion plethysmography in patients with idiopathic orthostatic hypotension.

In 3 patients suffering from idiopathic orthostatic hypotension (Shy-Drager's syndrome) venous distensibility was measured by occlusion plethysmography in supine and upright position. In this latter position, venoconstriction was absent, contrasting with the marked venoconstriction observed in normal volunteers studied under identical conditions. Venous occlusion plethysmography therefore seems to be useful to detect the autonomic defect leading to venous pooling. These patients were also immersed in water to the mid-abdomen while standing. This maneuver fully abolished orthostatic hypotension. Immersion is useful in motivating these patients to accept treatment by counterpressure garments, and makes early active physiotherapy possible.

[Pathology of shift work. Study of 4 state-owned factories]. / Pathologie du travail posté.

Out of 131 workers whose 2/3 are shifted, 6 have to stop shift-work due to diseases probably bound to the irregular schedule: the frequency of sleeplessness and absenteism was increased, and a loss of weight was noticed. The "psychological" troubles (irritability, tiredness) are more frequent among the shift-workers.

Intravenous glycerol in cerebral infarction: a controlled 4-month trial.

A double-blind, randomized trial was performed with 51 patients suffering from focal ischemic lesions in the territory of the middle cerebral artery. Intravenous infusions of 10% glycerol in 0.9% NaCl--5% glucose solutions were administered twice daily for 6 days to 26 patients, and the same amount of NaCl--glucose solutions to 25 controls. Glycerol did not reduce mortality (9 deaths in each group). The functional recovery was assessed by repeated neurological examinations during the 4 month trial. Glycerol significantly improved global performances and motor and sensory functions in patients with moderate disability, but its effect on global performances was transient. The patients with severe disability were not improved at all.

Effect of the menstrual cycle, oral contraception and pregnancy on forearm blood flow, venous distensibility and clotting factors.

Forearm blood flow, venous distensibility and various clotting factors were determined in 118 apparently healthy women (mean age 26 years), either during the menstrual cycle, or while taking a combined contraceptive (A) with high progestin:estrogen ratio (d-norgestrel 0.125 mg + ethinylestradiol 0.03 mg), or a sequential contraceptive (B) with low progestin: estrogen ratio (megestrol 0.1/1 mg + ethinylestradiol 0.1 mg), or in the 1st, 2nd and 3rd trimester of pregnancy. Venous distensibility in women taking contraceptive A was higher than in other women during the follicular phase of a normal menstrual cycle. Venous distensibility was not affected by contraceptive B. Blood flow and blood pressure remained unchanged by contraceptives A and B. Fibrinogen concentration was increased by both contraceptives, factor VII was either decreased (A) or unchanged (B), and factor X was either unchanged (A) or increased (B). The oral contraceptive with the high progestagen component appeared to increase venous capacitance and may induce venous stasis, whereas coagulability was particularly enhanced by the estrogen-type contraceptive. Pregnant women differed from women on oral contraceptives in regard to peripheral circulation; they showed a tremendous increase of blood flow with secondary vasodilation.

[Effect of glycerol on cerebral infarct]. / Effets du glycérol sur l'infarcissement cérébral.

Intravenous administration of glycerol under double-blind conditions (25 g twice daily for 6 days) to 26 patients with cerebral infarction localized in the territory of the middle cerebral artery temporarily improved the clinical evolution, as assessed by a scoring system, in comparison with 25 patients receiving placebo infusions.