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F Kamel

Publications and source records attributed to F Kamel.

45 records · Page 3Linked to original sources
PubMed1975

Characterization and physiological validation of a radioimmunoassay for plasma testosterone in the male rat.

A radioimmunoassay (RIA) to measure testosterone concentration in the plasma of male rats was formalized, tested and physiologically validated. The procedure measured testosterone equally well, whether or not estimation of recovery and chromatographic purification preceded the RIA. The results were equivalent to those achieved by the method of competitive protein binding. No 17beta-hydroxy-5alpha-androstan-3-one was found in the plasma of male rats. Adrenalectomy did not significantly decrease plasma testosterone in either male or female rats. The simplified protocol met all requirements of precision, sensitivity, accuracy and specificity. A single investigator can analyze 1,000 plasma samples for testosterone in one week if necessary.

Animals↗
PubMed1974

Reversion of frameshift mutations by mutator genes in Escherichia coli.

The Escherichia coli mutator genes mutU4, mutS3, and mut-25 (a possible allele of mutL), previously known to induce transitional base changes, increased significantly the frequencies of reversion of lacZ frameshift mutations. mutT1, previously shown to induce only the transversion of adenine-thymine to cytosine-guanine, had no effect on the reversion of lacZ frameshift mutations. With mutator genes other than mutT1, small increases were found in the frequencies of reversion of trpA frameshift mutations.

Acridines↗
PubMedDate not supplied

Intracellular receptors mediate gonadal steroid modulation of LHRH-induced LH release.

Primary cultures of enzymatically dispersed rat pituitary cells were used to study the role of intracellular receptors in gonadal steroid modulation of LHRH-induced LH release. Nuclear receptors for both testosterone (T) and 17 beta-estradiol (E) were observed, with KD values of 6.3 and 0.1 nM respectively. Occupation of these receptors was correlated with modulation of LH secretion. The relationship between these two parameters was nonlinear, so that steroid effects on LH secretion were maximal when fewer than 50% of the receptors were occupied. The androgen antagonist cyproterone blocked both T binding to nuclear receptors and T inhibition of LH secretion. Similarly, the estrogen antagonist CI-628 blocked both E binding and E stimulation of LH secretion. In cultures derived from pseudohermaphrodite rats. T did not bind to nuclear receptors, nor did it inhibit LH secretion. These results, showing a relationship between occupation of nuclear receptors and modulation of LH secretion, suggest that steroid effects on LH secretion are mediated by these receptors.

Animals↗
PubMedDate not supplied

Sexual behavior of a sample of females with epilepsy.

A sample of 700 female epileptic outpatients was examined between 1985 and 1987. The incidence of psychosexual disorders was 18%. Epileptic females with psychosexual disorders were compared with epileptic females without sexual disorders and with normal female controls on selected clinical and EEG parameters. Epileptic females with sexual disorders showed: lower marriage rates, a longer duration of illness, sexually colored prodromata, predominance of partial complex seizures (83%) and a higher incidence of menstrual abnormalities. Hyposexuality and exhibitionism were the psychosexual disorders most frequently noted. Temporal lobe EEG abnormalities were significantly higher.

Ambulatory Care↗
PubMedDate not supplied

Dietary intake of calcium, magnesium and antioxidants in relation to risk of amyotrophic lateral sclerosis.

Dietary factors have long been suspected of being risk factors for amyotrophic lateral sclerosis (ALS), but few human studies have been reported. To address several of the dietary hypotheses, a case-control study of risk factors for ALS conducted in New England in 1993-1996 included an abbreviated food frequency questionnaire. We examined the dietary intake of calcium, magnesium and antioxidants among 107 ALS cases and 262 community controls. Overall, these dietary factors were not related to risk of ALS, though modestly protective associations were suggested for magnesium and lycopene.

Adult↗