Occupational exposure to hexachlorocyclohexane. IV. Sex hormone alterations in HCH-exposed workers.

In a lindane (gamma-hexachlorocyclohexane)-producing factory 54 male workers (mean age 40 years, mean duration of exposure 8 years) were studied with regard to their blood levels of testosterone, LH, and FSH. Twenty clerks of nearly the same age were examined for control purposes in the same way. Serum-LH concentrations of the exposed workers were significantly higher than in controls.

Occupational exposure to hexachlorocyclohexane. II. Health conditions of chronically exposed workers.

Sixty male workers in a lindane (gamma-hexachlorocyclohexane)-producing factory were examined with regard to health in comparison with an external control group of 20 clerks. Case history, physical examination, neurologic status, and ECG revealed no significant differences between groups. However, the following significant differences in clinical-chemical blood tests were ascertained: higher polymorphonuclear leukocyte count, lower lymphocyte count, higher reticulocyte count, lower prothrombin (Quick's) test, and lower blood concentrations of creatinine and uric acid.

Occupational exposure to hexachlorocyclohexane. I. Body burden of HCH-isomers.

In a lindane (gamma-hexachlorocyclohexane = gamma-benzenehexachloride)-producing factor 57 workers were studied with regard to their blood levels of the three hexachlorocyclohexane isomers: alpha-, beta-, and gamma-HCH. The TLV-TWA (MAK value 1979) for gamma-HCH of 0.5 mg/m3 was not exceeded at any of the workplaces where HCH is synthesized and purified to lindane.

[Hormone-producing thyroid carcinoma with hyperthyroidism. Analysis of 6 cases and review of the literature].

Report on 6 female patients with follicular thyroid carcinoma producing hyperthyroidism. Two of them had large metastases with hormone production, while 4 mimicked an autonomously functioning thyroid adenoma. Hormone synthesis was investigated in the tumor tissue of one patient and was found to be similar to that of normal thyroid tissue.

Replication of mouse mammary tumor cells in monolayer cultures stimulated with embryo extract.

A particulate fraction derived from homogenized chicken embryos was added to primary monolayer cultures of mouse mammary tumor cells. All culture media contained fetal calf serum (10%). After 4 days, the extract had stimulated a twofold increase (relative to controls lacking the extract) in (1) total DNA per culture; (2) the rate of incorporation of labeled DNA precursors; (3) epithelial cell number, and (4) total protein.

Volume of brain ventricles in man determined by computer tomography.

In order to measure the absolute ventricular volumes in ml we developed a method using the numerical prints of CT (EMI, CT 1000) on which--by comparing with corresponding Polaroid photos--the margin between brain tissue and ventricles was drawn. For further evaluation, a curve digitizer and a digital computer were used. In 51 patients without any abnormal findings in CT, we studied the volume of single ventricles.

Quantitative studies of protein uptake in microperfused renal proximal tubules.

Proximal convoluted tubules were microperfused with an iodine 125 egg-white-lysozyme containing perfusion solution. The intraluminal lysozyme concentration decreased about 10% per mm tubular length over a wide range of intraluminal lysozyme concentrations tested indicating a constant fractional reabsorption over a wide concentration range. Lysozyme reabsorption at a high intraluminal lysozyme concentration of 10 mg/ml indicated that the tubular protein uptake by endocytosis is a saturable process.

The mechanism of action of harmaline on renal solute transport.

The effect of the hallucinogenic drug harmaline was tested on rat kidney proximal tubular solute and water transport, using in vivo micropuncture and electrophysiological techniques as well as in vitro biochemical techniques. During peritubular application harmaline (5 mmol/l) was found to block net tubular volume absorption reversibly (by 85%) through inhibition of active Na+ transport and possibly active HCO-3 transport. The inhibition was accompanied by a rapid strong depolarization of the tubular cell membranes.

Effect of parathyroid hormone and cyclic adenosine 3',5'-monophosphate on isotonic fluid reabsorption: polarity of proximal tubular cells.

Isotomic fluid reabsorption (JV) of rat renal proximal tubules was examined by the shrinking droplet method in combination with simulatneous perfusion of blood capillaries. Sensitivity of JV measurement was improved by using each punctured tubule for control measurements: 1) Parathyroid hormoen (PTH) on the contraluminal cell side reduced JV in a dose-response behavior. The maximal inhibition was achieved at a PTH concentration of 10(-5) M, the half maximal inhibition at a concentration of 3 X 10(-9) M.

[Neurotic disorders in monkeys during increased stress on analytic-synthetic processes].

It has been shown in experiments on three rhesus monkeys that an enhanced stress of analytical-synthetic processes consisting in learning to differentiate a sequence of tones, leads to neurotic disorders of monkeys higher nervous activity. They are manifested individually and consist in disturbances of general behaviour, in forced movements, breakdowns of differentiations, the missing of positive responses in the previously elaborated conditioned stereotype and in typical dynamics of the formation of positive and negative conditioned reflexes to a chain of tones (2000 + + 4000 c/s; 2000 + 2000 c/s; 4000 + 2000 c/s; 4000 + 4000 c/s).

On the action of nifedipine under conditions of variable stimulation patterns and [Ca2+]0 in guinea-pig atrium.

The effect of nifedipine is studied in perfused isolated guinea-pig left atrium at a temperature of 37 degrees C and a stimulation rate between 60 and 240/min. Rhythmical stimulation at 240/min was interrupted by interposed stimulus intervals (test intervals) in a range of 0.1-4 s.

Delay in diastolic restitution of full myocardial contractility in guinea pig atrium.

In an isolated perfused left atrium of guinea pig, pressure amplitudes were recorded at 37 degrees C and a stimulation rate of 240/min with interposed variable resting pauses. After prolonged intervals the preparation develops maximum pressure, which does not depend on perfusion time or on any positive inotropic intervention. The latter is found to shorten the time needed for restitution of full contractility.

[The effect of sudden changes in the stimulation rate of the heart on peak systolic pressure (author's transl)].

The changes in systolic pressure were studied in 48 patients during artificially (by electrical stimulation) induced sudden increases and consecutive decreases in heart rate. Various patterns could be separated respective to phase A (sudden switch from low (80-120 impulses/min) to higher heart rate (140-180 impulses/min)) and to phase B (sudden switch-back from high to lower (control) beating rate): AI) The systolic peak-pressure of the first contraction after the shortened stimulation interval is very low and often stays ineffective (below the aortic opening pressure). The second contraction develops already a higher pressure than the first one, during the consecutive beats the systolic pressure increases gradually until a new steady state is reached, which is usually lower than the systolic pressure during the foregoing lower beating rate.

Plasma renin activity (PRA) and plasma aldosterone (PA) in hypertensive kidney allograft recipients.

Basal and stimulated plasma renin activity (PRA) and plasma aldosterone (PA) were measured in 13 hypertensive and 16 normotensive patients with kidney allografts one to nine years after transplantation. In both groups no significant differences were observed between mean basal and stimulated PRA and PA values. Therefore, we conclude that abnormal renin secretion might not be the main factor causing hypertension in renal allograft recipients.

Effect of cyclic nucleotides on the isotonic fluid reabsorption in the proximal convoluted tubule of rat kidney.

In order to reveal the sidedness of the cyclic AMP action on renal tubules the effect of cyclic nucleotides on isotonic fluid reabsorption was examined in proximal convoluted rat kidney tubules by using advanced micropuncture techniques. Cyclic AMP inhibited isotonic fluid reabsorption preferentially when applied on the luminal cell side. This finding coincides with a predominant distribution of a membrane bound cyclic AMP dependent protein kinase in a luminal cell membrane fraction.

Renal proximal tubular buffer-(glycodiazine) transport. Inhomogeneity of local transport rate, dependence on sodium, effect of inhibitors and chronic adaptation.

Using the stop flow microperfusion technique with simultaneous capillary perfusion the secretory rate of H+ ions in the proximal tubule was evaluated by measuring the level flow reabsorption as well as the static head concentration difference of 3H labeled glycodiazine. At ambient glycodiazine concentration of 21 mmol/l the level flow reabsorption is in the same range as that of bicarbonate. In the early proximal loops the reabsorption is 20% greater than in the late proximal loops.

[Stress sensitivity and adaptation].

On the basis of theoretical, clinical and experimental analyses the influence of different stress categories, especially of psycho-emotional and socio-emotional stress, upon cerebro-visceral regulation processes is investigated. Central-nervous information processing in various brain areas (neocortex, limbic system, hypothalamus, formatio reticularis mesencephali etc.) and learning processes are equally affected by stress factors as are haemodynamic and biochemical parameters.

Renal phosphate transport: inhomogeneity of local proximal transport rates and sodium dependence.

The standing droplet method has been used in combination with the peritibular perfusion of blood capillaries to determine the build up of transtubular concentration differences of phosphate (Piota) in the renal proximal convoluted tubule of parathyroidectomized rats. Electron probe analysis was used to estimate Piota. At zero time both the intraluminal and the contraluminal Piota concentration was 2 mM.