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Biomedical subjects

L Singer

Publications and source records attributed to L Singer.

At least 127 records · Page 7Linked to original sources
PubMed1980

[Lithium elimination by the isolated perfused rat kidney (author's transl)].

The pharmacokinetics of lithium, a drug with a narrow therapeutic index, depends on the renal elimination of the metal. An open circuit, constant flow isolated rat kidney preparation perfused with gelatinized (Haemaccel) Krebs-solution, was used to study the urinary elimination of lithium relative to sodium. A series of 88 kidney preparations perfused with a solution containing 0.47 mmol/l lithium was compared to another of 52 kidney preparations perfused without lithium. Lithium reduced the tubular reabsorption of sodium but did not modify the elimination of potassium. There is a strong correlation between the tubular reabsorption of lithium and of sodium. The correlation between tubular reabsorption of lithium and filtered load demonstrates the existence of a glomerulo-tubular balance.

Animals↗
PubMed1979

Lack of cytogenetic effects in mice or mutations in Salmonella receiving sodium fluoride.

We have examined the possible effect of fluoride intake on chromosome damage. There was no evidence of increased frequency of chromosomal aberration in bone marrow or testis cells of mice with either 50 ppm fluoride intake over several generations or 100 ppm intake for 6 weeks compared to animals drinking distilled water. Fluoride was not found to be mutagenic in a widely used bacterial mutagenesis assay over a range of 0.1 to as high as 2000 microgram fluoride per plate.

Animals↗
PubMed1979

Lack of effect of fluoride on urinary cAMP excretion in rats.

The urinary excretion of cyclic 3'5'-adenosine monophosphate (cAMP) was measured in rats provided a low fluoride diet (less than 0.5 ppm) and drinking water containing either 0 or 25 ppm of fluoride. The pMole cAMP/microgram creatinine ratio decreased with age but was not influenced by fluoride intake.

Animals↗
PubMed1979

[Lithium and thyroid function. Significance of the TRH test in the diagnosis of lithium-induced thyroid dysfunction].

The treatment by lithium is known to involve certain endocrine complications. Those concerning the thyroid function, with risk of a frank hypothyroidy, are the most important. Aiming to appreciate the frequence and the intensivity of the endocrine effects of lithium, the thyroid parameters and the steady state of the hypothalamo-pituitary-thyroid axis were tested using the TRH test in 52 patients with maniaco-depressive psychosis with special attention to TSH, prolactin and growth hormone: 24 out of them were treated for 1 month to 6 years by lithium; the 28 others were considered as controls. The lithium treatment involves a decrease in the free thyroxine index (1.78 +/- 0.09 vs 2.16 +/- 0.09; p less than 0.01), an increase in the mean baseline TSH level (5.80 +/- 1.49 vs 2.70 +/- 0.24 microU/ml; p less than 0.05) and a noteworthy increase in the TSH responsiveness to TRH (22.7 +/- 2.14 vs 9.75 +/- 1.63 microU/ml; p less than 0.005). The TSH supranormal responses were neither correlated with the length of the treatment nor with the age of the patients. They appear as the consequence of a decrease in the thyroidal hormone secretion. The basal and stimulated prolactinemias remain comparable in the two groups of patients and no response of growth hormone occured after TRH. The TRH test must be considered as a useful complement for the surveillance of the patients treated with lithium because it permits to diagnose early the lithio-induced thyroid dysfunction.

Adolescent↗
PubMed1979

Concentrations of ionic, total, and bound fluoride in plasma.

We found no significant difference between the means for ionic, bound, and total fluoride concentrations in the plasma of male and female subjects of the same age, living in a community with fluoridated water. When results for the 264 fasting subjects were therefore combined according to age, they indicated that persons over 60 years of age have a significantly higher mean ionic (3.89 mumol/L) and total (6.58 mumol/L) fluoride concentration in plasma than do younger age groups. For younger age groups, means ranged from 2.74 to 3.05 mumol/L for ionic fluoride and from 4.74 to 5.58 mumol/L for total. The bound fluoride concentration was lower in individuals 21 to 30 years of age (1.89 mumol/L) than in older age groups (for whom means ranged from 2.42 to 2.68 mumol/L), but was not significantly different from that of individuals who were younger (2.21 mumol/L). A tendency for the mean ionic fluoride concentration to increase with age was noted, but the concentration was significantly higher than the preceding decade group only in those persons over 60 years of age.

Adolescent↗
PubMed1979

Total fluoride intake of infants.

The fluoride content of commercially prepared infant foods processed in fluoridated and nonfluoridated plants has been determined. The use of fluoridated water during processing has been shown to increase significantly the fluoride content of certain infant foods. The data obtained have been employed to calculate the minimum and maximum total daily fluoride intake for infants up to 6 months of age. The maximum total daily fluoride intake for infants up to 6 months of age is 0.127 mg of fluoride per kilogram of body weight. An infant consuming human milk or cow's milk and living in a community that does have fluoridated water has a substantially lower total daily fluoride intake.

Animals↗
PubMed1978

The effects of high and low fluoride diets on the frequencies of sister chromatid exchanges.

A recent report suggests that fluoride has mutagenic activity in mice. To examine the potential clastogenic effect of ingested fluoride, we examined the frequencies of baseline SCE and mitomycin C induced SCE as well as baseline chromsomal aberrations and cell-cycle kinetics in mice raised on high and low fluoride diets. The lack of significant differences in any of these parameters between the two groups of animals indicates that dietary fluoride is not clastogenic and supports the continued use of water fluoridation.

Animals↗
PubMed1978

Long-term follow-up of photocoagulated retinal breaks.

126 cases of retinal breaks treated in our department by photocoagulation during a period of 10 years (1963-1973) were selected for a close annual follow-up. Eliminated from the study were cases of macular holes, breaks which developed in an eye after retinal detachment surgery, and cases in which a close follow-up was impossible for various reasons. The study includes symptomatic retinal breaks in myopic, non-myopic, and aphakic eyes as well as asymptomatic holes which were found in the undetached fellow eye. Four eyes treated by photocoagulation (3.2%) developed a retinal detachment. The causes of failures and complications, such as retinal detachment, vitreous haemorrhage, and macular pucker, are discussed.

Adolescent↗
PubMed1978

[The effects of phenylbutazone on the decrease of lithium clearance].

During the treatment of a manic depressive patient, the authors reported some lithium toxicity signs, as lithium carbonate (3 X 300 mg p.d.) and phenylbutazone suppository (3 X 250 mg/p.d.) were associated, this last medication being prescribed for a phlebitis. Lithiemia increased from .70 to 1,44 mEq/l., the lithiemia clearance falling from 10 ml to 5 ml/mn/1.73 m2) and the lithium tubular reabsorption percentage increasing from 85 to 94% (standard rates: 77.4 +/- 1.3%). In a second time, a rat experimentation corroborated these findings: phenylbutazone treatment (100 mg/kg/p.o. for five days) resulted in a lithium tubular reabsorption increase. It seems that the association of lithium carbonate with phenylbutazone should be avoided. The authors point out the risk of prescribing lithium and pyrazolic by-products as phenylbutazone, which are potentially nephrotoxic.

Animals↗
PubMed1978

Unusual course and long-term follow-up in malignant glaucoma.

One man and 2 women, aged 67, 63 and 68 years, observed for 8, 6, and 2 years, developed a classical postoperative malignant glaucoma. After a second operation, the use of atropine drops was continued for 2 years in one case, whereas in the other 2 cases miotics and later acetazolamide (Diamox) were necessary in order to maintain normal intraocular pressure. All 3 patients refused a preventive operation in the fellow eye and the use of miotics proved both necessary and effective in maintaining normal intraocular pressure, normal visual acuity, and normal visual fields.

Acetazolamide↗