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Biomedical subjects

R L Young

Publications and source records attributed to R L Young.

At least 55 records · Page 3Linked to original sources
PubMed1990

Stages of adolescent tobacco-use acquisition.

The present study extended the results of previous research in applying the "stages of acquisition" model to the onset of smokeless tobacco as well as cigarette use. Three expert judges classified an initial pool of items as to whether they represented "precontemplation," "contemplation," "action," or "maintenance" stages of smokeless tobacco acquisition. Fifty items with adequate inter-rater reliability were combined with 21 previously developed items pertaining to cigarette smoking acquisition in an overall tobacco acquisition questionnaire, which in turn was administered to 358 junior and senior high public school students. Three distinct components labeled precontemplation, action, and maintenance were delineated through principal component analyses. Coefficient alphas and discriminant analyses according to self-reported use demonstrated adequate reliability and validity for the new smokeless tobacco- and previously developed smoking-acquisition scale.

Adolescent↗
PubMed1990

Meiotic recombination between yeast artificial chromosomes yields a single clone containing the entire BCL2 protooncogene.

The common translocation found in human follicular lymphoma, t(14;18)(q32;q21), results in deregulation of the BCL2 protoonocogene. The isolation of the intact gene would provide an essential substrate to analyze the molecular basis of this malignancy. Pulsed-field gel electrophoresis suggested that this three-exon gene was several hundred kilobases (kb) long. Therefore, a library of yeast artificial chromosome (YAC) clones was screened to isolate the intact BCL2 gene. Two clones, yA85B6 (200 kb) and yB206A6 (700 kb), were isolated by using polymerase chain reaction (PCR) assays specific for exon I/II and exon III, respectively. However, neither YAC contained the entire BCL2 locus. Since the two YACs were found to overlap by 60 kb, we sought to take advantage of the high recombination frequency in yeast and induce physical recombination between the two clones. Cells containing each YAC were mated and induced to undergo meiotic division and sporulation. Analysis of the resulting tetrads revealed a spore containing a single recombinant YAC of 800 kb. PCR assays and Southern blotting demonstrated that this recombined YAC contained the entire approximately 230-kb BCL2 gene. Furthermore, probe order was conserved and there was no evidence of overt rearrangements or deletions. These results indicate the feasibility of reconstructing large genomic segments with overlapping YAC clones to study genes spanning hundreds of kilobases.

Chromosomes, Fungal↗
PubMed1990

Correlates of health facilitator performance in a tobacco use prevention program: implications for recruitment.

Tobacco use prevention programs vary by type of health facilitator used to deliver the intervention. Because program outcome may be related to the characteristics of a health facilitator, this study investigated the association between the characteristics of 29 college undergraduate health facilitators of an adolescent tobacco use prevention program with their scores on manageability and inclass performance scales. Results indicated health facilitators who rated themselves as outgoing, adventurous, analytical, and were older rated higher on the inclass performance scale. Facilitators who self-reported they wanted an easy class, had lower grade point averages in their academic major, were less outgoing, and wanted to attend graduate school were rated higher on the manageability scale. Inclass performance scales and ratings on the manageability scale correlated negatively. Implications for health facilitator recruitment are discussed.

Adolescent↗
PubMed1990

Management of menopause when estrogen cannot be used.

Estrogen deficiency, whether surgically induced or as a consequence of natural ovarian failure, has destructive effects on many organ systems. With current levels of life expectancy, untreated women may expect to spend a third of their lifetime in this state. Appropriate estrogen replacement therapy (ERT) can avert (if started promptly) or ameliorate these devastating consequences, some of which (osteoporotic fractures, increased cardiovascular morbidity) can be lethal. Nevertheless, from 10 to 20% of postmenopausal women may have significant contraindications to ERT. Treatment of symptoms and improving the quality of life is imperative, yet many physicians abjure intervention, for reasons which are not entirely clear. Recent studies of conventional intervention with sedatives or tranquilisers show results equivalent to placebo therapy. On the other hand, specific agents with demonstrated effectiveness are available for management of the major estrogen-deficiency effects, although none of them are truly adequate replacement for the effect of estrogen itself.

Contraindications↗
PubMed1989

The effect of triphasic oral contraceptives on plasma lipids and lipoproteins.

To determine the effect of triphasic oral contraceptives on plasma lipid transport, 150 nonsmoking women with normolipidemia, ages 18 to 35 years, were randomly assigned to receive one of three contraceptive formulations: (1) ethinyl estradiol, 30, 40, and 30 micrograms/day, each for 6, 5, and 10 days per menstrual cycle, and levonorgestrel, 50, 75, and 125 micrograms/day, each for 6, 5, and 10 days; (2) ethinyl estradiol, 35 micrograms/day for 21 days, and phased norethindrone, 500, 750, and 1000 micrograms/day each for 7 consecutive days; and (3) ethinyl estradiol, 35 micrograms/day for 21 consecutive days, and norethindrone, 500, 1000, and 500 micrograms/day for 7, 9, and 5 days, respectively. A control group consisting of 49 women taking a nonhormonal form of contraception was also included. After 6 months of oral contraceptive treatment, significant increases in plasma triglyceride (28% to 52%) and plasma apolipoprotein B levels (20% to 23%) were observed in each treatment group. The changes in total plasma cholesterol (3% to 10%) and low-density lipoprotein cholesterol values (0% to 11%) were less striking. Changes in total high-density lipoprotein cholesterol levels were statistically insignificant (-2% to -4%); however, high-density lipoprotein2 cholesterol levels decreased by 29% to 33% and high-density lipoprotein3 cholesterol levels increased by 20% to 23%. Concomitantly, plasma apoliporprotein A-1 values increased by 5% to 12%. No consistent significant differences among analyses were observed between and of the groups receiving different oral contraceptives for 6 months.

Adolescent↗
PubMed1989

Risk of pregnancy and dropping out of school among special education adolescents.

This study examined the temporal relationship between dropping out of school and teen-age pregnancy, and whether or not teens in special education programs are at greater risk for pregnancy and dropping out than non-special education teens. Cumulative Student Records and case files were reviewed on a random sample of 135 already pregnant girls served by the San Diego Adolescent Pregnancy and Parenting (SANDAPP) program. A comparison was made of ages at time of dropping out and conception of the first live birth between special education and non-special education groups. The overall prevalence of special education teens in the program was compared with the prevalence rate of 10% in the San Diego Unified School District. Results indicated 20% of SANDAPP adolescents were in special education compared to 10% for the overall school district. Special education teens dropped out of school significantly earlier than non-special education teens. No significant evidence supported the hypothesis that teens dropped out of school first, then became pregnant. Nor was there significant evidence to suggest special education teens experience their first live birth at younger ages than their non-special education counterparts. No relationship was found between mean grade point average and age at conception. The researchers concluded that special education teens are at higher risk for pregnancy and dropping out of school than non-special education teens.

Adolescent↗
PubMed1989

Generic tobacco use among four ethnic groups in a school age population.

The prevalence of overall or "generic" tobacco use among Hispanic, white, Black and Asian youths in grades four, seven, ten and twelve was compared in San Diego, California (n = 4980). Significant differences in generic tobacco use between ethnic groups were found in the 4th, 10th and 12th grades, but were greatest in the 10th grade. Only white youths demonstrated a sharp increase in regular tobacco use (once a month or more) between 7th and 10th grade. Overall, the prevalence of regular use was highest among whites (25.8%), followed by Hispanics (19.7%), Blacks (17.6%) and Asians (12.6%). Marijuana, alcohol, and other drug use explained approximately 40 percent of the variance in tobacco use in each ethnic group. Other predictors varied by ethnicity and included socioeconomic status, happiness of student, strictness of parent, adult tobacco use at home, accessibility to marijuana, and gender.

Adolescent↗
PubMed1989

Pelvic inflammatory disease complicated by massive helminthic hyperinfection.

Strongyloidiasis is a potentially life-threatening condition which, when appropriately diagnosed early in its course, is easily eradicated. When severe, it may mimic other disease processes including appendicitis or severe pelvic inflammatory disease. The diagnosis of parasitic infestation should be considered in any individual who has lived in an endemic area and presents with diarrhea regardless of attendant conditions and superimposed disease processes. A minimum workup consisting of stool examination for ova and parasites should be performed on all such individuals. Thiabendazol is the treatment of choice in nonpregnant patients; however, piperazine tartrate has established safety and efficacy in pregnancy and is therefore preferable in the pregnant patient.

Adult↗
PubMed1988

Availability of organic chemicals for biodegradation in settled bottom sediments.

Biodegradation rates for dodecyltrimethylammonium chloride (TMAC), a quaternary ammonium compound, and phenol were measured in settled sediments to determine if adsorbed chemicals were directly available for biodegradation by sediment-associated bacteria. In settled sediment cores, biodegradation rates for TMAC, which is charged at environmental pH, was a function of the amount of unadsorbed chemical; adsorbed material was not directly degraded by the sediment-associated bacteria. However, the rate of biodegradation of adsorbed phenol, a relatively hydrophobic and neutral chemical, was apparently a function of the total concentration of material present, suggesting that at least a fraction of the adsorbed material was directly degraded. These results indicate that chemical structure and, possibly, the mechanism of adsorption may influence biodegradation in sediments. Studies on TMAC biodegradation in completely mixed sediment/water slurries (up to 10 g/liter sediment) showed that TMAC biodegradation in slurries differed from that in settled sediments. Biodegradation in slurries was a function of the total amount of material present, both adsorbed and unadsorbed. These results suggest that biodegradation in settled sediments may be influenced by high concentrations of sediment present and/or the lack of mixing. Thus mixed, low-sediment-level slurries may not be realistic surrogates for modeling biodegradation processes in settled bottom sediments.

Adsorption↗
PubMed1988

Tobacco use prevention and health facilitator effectiveness.

Tobacco prevention programs often use peers to teach refusal skills to other adolescents. College undergraduate health facilitators delivered a tobacco prevention intervention to sixth and seventh grade students in six schools. Outside observers evaluated facilitators in seven categories: being prepared, maintaining class control, keeping students' attention, encouraging participation, communication, relating to students, and working well in a team. Facilitators were rated highly in all categories. Higher rated health facilitators had more effect in reducing tobacco use than poorly rated facilitators. Facilitators who worked well in a team, related well to students, and were well-prepared were especially effective in positively influencing program outcomes.

Adult↗
PubMed1988

Clinical manifestations of polycystic ovarian disease.

Elevated androgens and/or increased sensitivity to them is at the core of polycystic ovarian disease (PCOD). In orbit around this essential element are a wide variety of signs and symptoms that may come into alignment in unpredictable fashion and frequency. This article considers the clinical history and physical examination of the patient with PCOD, ovarian morphology, the laboratory work-up of patients with PCOD, and the role of ultrasonography, magnetic resonance imaging, and laparoscopy in the diagnosis of PCOD.

Androgens↗
PubMed1988

Sigmoidovaginal fistula secondary to diverticular disease. A report of three cases.

Colovaginal fistula from any cause is rare. Diverticular disease is the most common cause. We treated three women for sigmoidovaginal fistulae secondary to diverticular disease. These 3 cases bring the total number reported to 49. Diagnosis of these fistulae may be difficult, and controversy exists over which form of surgical management should be employed. Since more women are living to an age at which diverticular disease is common, colovaginal fistulae probably will be encountered by the gynecologist with increasing frequency. Colovaginal fistula secondary to diverticular disease should be considered in the differential diagnosis when an elderly women complains of flatus vaginalis.

Aged↗
PubMed1987

Comparison of OECD and radiolabeled substrate methods for measuring biodegradation in marine environments.

Two methods for assessing biodegradation in marine environments, the OECD method, and a method using radiolabeled test substrate, were compared utilizing a model aromatic compound, benzoic acid. In samples from a relatively unimpacted estuary, Santa Rosa Sound, definitive biodegradation at 20 mg/liter was not detected by either method. However, the radiolabeled substrate method measured rapid biodegradation of the material at 50 micrograms/liter, which approximates expected environmental concentrations. In the Fraser River Estuary, which receives large discharges of municipal wastewater, biodegradation of benzoic acid was rapid at both 20 mg/liter and 50 micrograms/liter, and was detected by both methods. The results of the study illustrate the utility of radiolabeled substrates for determining the biodegradation of synthetic chemicals. Methods such as the OECD technique are very useful screening tools for assessing the overall potential of a chemical to biodegrade. However, such techniques generally cannot measure biodegradation at realistic concentrations. The use of radioisotopes in biodegradation studies can significantly increase the sensitivity of biodegradation measurements. As a result, realistic estimates of biodegradation can be obtained at concentrations which are often outside the scope of screening methods.

Benzoates↗
PubMed1987

The endocrine effects of spironolactone used as an antiandrogen.

Eight castrate, estrogen-replaced women were given 200 mg spironolactone daily for 4 weeks. The response of plasma dehydroepiandrosterone sulfate (DHEAS), testosterone (T), and androstenedione (delta 4A), all indicators of adrenal C19-steroid production, varied greatly among individuals. Sixteen women with idiopathic hirsutism were given night-time dexamethasone (DEX) and then superimposed spironolactone for 4 weeks, followed by DEX without spironolactone for an additional 4 weeks. As expected, DHEAS, T, and delta 4A declined on DEX treatment. On addition of spironolactone, there was little further change in DHEAS, while plasma T declined in 7 of 16 women, including all those whose T level had remained elevated despite DEX treatment; most values rebounded when spironolactone was discontinued. The authors conclude from intact DEX-suppressed women that ovarian T, especially when increased, is frequently lowered by spironolactone. Thus, both adrenal and ovarian androgen production (as measured by prevailing plasma levels) may be diminished by this agent. These highly variable effects on androgen production are unlikely to account for the consistent antiandrogenic effects reported clinically.

Adult↗
PubMed1987

Comparison of in vitro fertilization results in women with one or two ovaries.

A study compared the in vitro fertilization results in women with one or two ovaries. Eighteen percent (23/125) of in vitro fertilization/embryo transfer cycles were in patients with one ovary. One-ovary patients averaged 4.2 follicles (greater than or equal to 10 mm) as compared to 7.9 in two-ovary patients, and significantly fewer ova were recovered from one-ovary patients (4.0 vs. 5.3). The total follicular volume was significantly less in one-ovary patients as compared to two-ovary patients, and the serum estradiol per follicle was less in one-ovary patients. However, the volume of the dominant follicle, the maximum serum estradiol levels, the number of ampules of Pergonal given and the ovum fertilization rate were not significantly different in one- and two-ovary patients. The mean number of embryos transferred was 3.9 +/- 1.9 in one-ovary patients and 4.5 +/- 1.8 in two-ovary patients (NS). Two pregnancies occurred in one-ovary patients (8.3% per laparoscopy) and 13 in two-ovary patients (12.9% per laparoscopy). The two one-ovary patients who achieved pregnancy behaved more like two-ovary patients in terms of peak serum estradiol levels and number of ova recovered.

Adult↗