PubMed Health⌕ Search

Biomedical subjects

R L Lee

Publications and source records attributed to R L Lee.

16 recordsLinked to original sources
PubMed1992

Population genetics of colonic cancer.

BACKGROUND: There are several well known but rare syndromes of inherited colonic cancer. Genetic epidemiologic studies also have demonstrated that relatives of individuals with colonic cancer in general exhibit an excess risk for this malignancy. METHODS: This report reviews the literature pertinent to genetic and familial risk for colonic cancer with emphasis on the recent work that suggests that inherited susceptibility to colonic neoplasms is common. RESULTS: The adenomatous polyposis syndromes are rare inherited colonic cancer conditions caused by a mutant gene which recently has been characterized. Hereditary nonpolyposis colorectal cancer is likewise inherited and may account for up to 5% of cases. The molecular genetics of this disease remain to be clarified. The majority of colonic cancer cases are considered sporadic but are known to often cluster in families. Recent work suggests that inherited susceptibility may be the basis of this familial occurrence. Screening strategies based on inherited and familial risk are suggested. CONCLUSIONS: Knowledge of the familial and inherited risk for colonic cancer is leading to a better understanding of this disease and is suggesting more directed preventive strategies.

Adenomatous Polyposis Coli↗
PubMed1992

Hereditary aspects of colorectal adenomas.

BACKGROUND: Inheritance is important to the development of colonic adenomatous polyps and colon cancer. Current knowledge of inherited susceptibility to colonic neoplasms suggests that colon cancer screening strategies should consider familial and genetic risk. METHODS: This report reviews the literature pertinent to adenomatous polyp and colon cancer inheritance and suggests polyp-cancer screening procedures based on inherited or familial risk. RESULTS: Colorectal adenomas and cancer occur in several rare inherited syndromes and more commonly as sporadic cases. Intensive screening protocols have been suggested for the inherited syndromes because of the high associated cancer risk. Recent evidence suggests that inherited susceptibility also may be important in a large fraction of the so-called sporadic cases. Preliminary screening guidelines are suggested for this category based on the number of first-degree relatives affected with colon cancer. CONCLUSIONS: Inherited susceptibility appears to be more important to the pathogenesis of colorectal adenomas and cancer than previously recognized. Screening strategies which consider inherited risk may increase the effectiveness of cancer detection and prevention.

Adenoma↗
PubMed1990

Effects of intrathecal administration of 8-OH-DPAT on genital reflexes and mating behavior in male rats.

Systemic administration of the 5HT1A receptor agonist, 8-OH-DPAT, consistently decreases the threshold of ejaculatory behavior and enhances some aspects of arousal. Previous findings by others demonstrated the in copula ejaculatory behavior effect using intrathecal (IT) injection at the level of the lumbosacral spinal cord, but the dose used was in the range that produced results systemically. This study aimed at a) a more comprehensive study of the sexual effects of 8-OH-DPAT and b) use of IT doses of 8-OH-DPAT below those effective when administered systemically. The ex copula genital reflex test showed severe inhibition. At doses of 5 micrograms or more, significant inhibition of the percentage of rats displaying ejaculation occurred, and the two highest doses also significantly reduced the percentage of rats displaying erection. In the in copula mating test, 20 and 80 micrograms IT 8-OH-DPAT, significantly reduced ejaculation latency, intromission frequency and intercopulatory interval. Copulatory plugs, collected at the highest dose only, showed a trend towards weight reduction. We conclude that the facilitation of ejaculatory behavior and some measure of arousal by 8-OH-DPAT can be mediated directly via the lumbosacral spinal cord. An hypothesis for explaining the inhibitory effect on ejaculation ex copula is presented, but the inhibitory effect on erectile reflexes is without interpretation.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1989

The relationship between cholecystectomy and colon cancer: an Iowa study.

The relationship between cholecystectomy and subsequent development of colon cancer was investigated in a case-control study of 165 patients with histologically proven adenocarcinoma of the colon. These patients were from a community in Iowa where incidence of colon cancer was considered to be higher than average in the United States. The relative risk of developing colon cancer after cholecystectomy was shown to be 2.11 (P = .009) for the entire series and 2.91 (P = .002) for the female group. There was a difference of frequency in developing colon cancer after cholecystectomy between the right- and left-sided colons; the relative risk of the right versus the left colon cancer was 2.31 (P = .019). The other factors, including blood group, red cell indices, obesity, serum cholesterol, colonic diverticula, and co-existence of hyperplastic or adenomatous polyp disclosed no significant relation to colon cancer developed after cholecystectomy.

Adenocarcinoma↗
PubMed1989

A component analysis of the effects of DPAT on male rat sexual behavior.

Male rat sexual behavior was examined in a variety of tests following a single acute IP injection of the serotonin1A (5-HT1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (DPAT). The objective was to determine the effects of 5-HT1A receptor stimulation on the components of sexual behavior (arousal/motivation, erection and ejaculation) using this prototypical 5-HT1A ligand. In the ex copula genital reflex test, DPAT dramatically inhibited ejaculation and the display of penile erections. When examined in the mating behavior test, DPAT caused a significant reduction in intromission frequency (IF), ejaculation latency (EL), intercopulatory intervals (ICI) and postejaculatory interval (PEI). The decrease in IF and EL indicated a lowering of the behavioral-ejaculatory threshold, while the reduction in ICI and PEI indicated a stimulation of two aspects of sexual arousal. Further tests, however, revealed complexities. Using the mounting test (with genital anesthesia) as an assessment of sexual arousal, no effect of DPAT was found. Collection and examination of the coagulated ejaculates resulting from mating (copulatory plugs) provided evidence of an impairment in ejaculation, as a result of DPAT treatment. The data suggests that 5-HT1A receptor stimulation lowers the behavioral-ejaculatory threshold despite inhibition of ejaculation in and ex copula; as well as stimulating specific aspects of sexual arousal. It remains to be determined whether the effects on arousal were either due to nonselectivity as currently believed or because 5-HT1A receptor stimulation affects alpha 2-adrenoceptor activity by some as yet undefined mechanism; and as a result modulates sexual arousal.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1987

Alpha 2-adrenoceptor antagonists and male sexual behavior: I. Mating behavior.

Three alpha 2-adrenoceptor antagonists yohimbine, idazoxan, and imiloxan were compared by examining the effects of a single injection on male rat copulatory behavior. Dose ranges were: yohimbine: 0.25-8.0 mg/kg; idazoxan: 0.25-8.0 mg/kg; imiloxan: 12.5-50.0 mg/kg. Yohimbine and idazoxan administration produced significant increases in the number of animals copulating to ejaculation and all three drugs increased the rate of copulation as evidenced by reductions in ejaculation latency and intercopulatory interval. Only yohimbine significantly reduced mount latency and postejaculatory interval, but yohimbine and imiloxan significantly reduced intromission latency and idazoxan showed a similar trend. The highest yohimbine dose suppressed sexual activity. A time-course experiment with yohimbine (2.0 mg/kg) and idazoxan (4.0 mg/kg) showed stimulation at 75 min and a trend at 5. To further explore the arousal-stimulating capacity of the two more effective drugs, a mounting test with genital anesthetization was used. Yohimbine but not idazoxan showed marked increases in mounting at 1.0-4.0 mg/kg. Both drugs had a suppressive effect at the highest doses. These data support the involvement of alpha 2-adrenoceptors in the regulation of male sexual behavior, specifically by facilitating sexual arousal, with no effects on ejaculatory threshold, as measured by intromission frequency. Yohimbine is the most globally effective agent and it is likely that factors other than yohimbine's alpha 2-antagonism may play a role in its unique, consistent and broad behavioral effects.

Adrenergic alpha-Antagonists↗
PubMed1987

Alpha 2-adrenoceptor antagonists and male sexual behavior: II. Erectile and ejaculatory reflexes.

Three alpha 2-adrenoceptor antagonists, yohimbine, idazoxan, and imiloxan, all shown to have stimulatory effects on sexual arousal/motivation, were studied to identify their possible effects on the other two major components of male copulatory behavior: erection and ejaculation. Genital reflex ex copula tests were used in order to assess these two responses without the confounding factors of mating behavior. Dose ranges were yohimbine: 0.25-4.0 mg/kg; idazoxan: 1.0-8.0 mg/kg; and imiloxan: 12.5-50.0 mg/kg. Lower doses of two of the drugs significantly enhanced the frequency of erections, while the third (yohimbine) showed a strong trend in that direction. At higher doses, all three alpha 2-antagonists produced significant reductions in the number of rats showing penile reflexes, including both erections and ejaculations. In those rats which did show penile reflexes, higher doses of yohimbine (4.0 mg/kg) inhibited the frequency of erections, while the higher dose of idazoxan showed a trend towards such inhibition. Thus, profound, largely inhibitory effects of these agents were demonstrated at dose ranges which have been shown to enhance sexual arousal. These data indicate that within the nervous system alpha 2-adrenoceptor antagonists can modulate erectile and ejaculatory mechanisms quite independently from effects on arousal/motivation.

Adrenergic alpha-Antagonists↗
PubMed1976

Clincal observations of sex as a reverberation of the total relationship.

In the psychiatric treatment of sexual dysfunctioning the generally accepted method has been to concentrate heavily on the intrapsychic conflicts of one or both spouses. There now is increasing evidence that treatment is sometimes more effective if the therapeutic intervention takes place directly in the interpersonal system. Such evidence has been provided by those therapists with clinical experience in marital systems who are prepared to utilize theories evolved from a multidisciplinary approach to marital problems. This paper is meant to discuss and illustrate this shift in treatment strategy as it applies to sexual dysfunctioning and deals with the function of the interplay of sex, love, and commitment through the illustrative cases.

Female↗