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Biomedical subjects

R L Collins

Publications and source records attributed to R L Collins.

At least 73 records · Page 4Linked to original sources
PubMed1990

Endorsement and strength of alcohol expectancies.

It has been suggested that the strength of alcohol-related expectancies can be ascertained from the number of items endorsed on subscales consisting of multiple items. In the present study, subjects were asked to rate the strength of their beliefs in addition to indicating whether or not they endorsed the items on a measure of alcohol-related expectancies. Three issues were addressed: (1) Do strength ratings and endorsements predict the perceived likelihood of drinking when their correlated effects are taken into consideration and do these responses interact? (2) Do the endorsements and strength ratings form higher order factors? and (3) Do men and women with various drinking habits rate the strength of their beliefs for a moderate and a large dose of alcohol in a way that mirrors their endorsements? The results suggest that the strength of an alcohol-related expectancy must be measured in its own right and cannot be inferred from the pattern of endorsements. Interactions of endorsements and strength ratings produce unique information that is not deducible from either measure alone.

Adolescent↗
PubMed1990

Pneumomediastinum and subcutaneous emphysema during laparoscopy.

Laparoscopy, with the use of carbon dioxide or nitrous oxide for insufflation is a common procedure with the potential for several major complications. For example, pneumomediastinum, pneumothorax, and subcutaneous emphysema can occur singly or in any combination with this procedure. The authors report a patient in whom pneumomediastinum and massive subcutaneous emphysema developed without pneumothorax. Possible mechanisms are presented, along with discussion of the need for prompt diagnosis and termination of the procedure with deflation of the abdomen. The life-threatening potential of this complication is emphasized.

Adult↗
PubMed1990

A quantitative study of cerebrovascular variation in inbred mice.

The arteries of the base of the mouse brain were examined after perfusion with India ink. A qualitative difference exists between inbred mice of three strains (C57BL/6J, 129/J and BALB/cCF) on the one hand, and genetically defined heterogeneous mice on the other; the latter consistently show anomalies similar to those previously described in genetically undefined rodents, whereas inbred mice do not. A quantitative morphometric analysis of the Circle of Willis of inbred mice was undertaken. The results of this analysis are consistent with the notion that the differences in shape between the circles of Willis of different strains of inbred mice are due to additive genetic variation between these strains.

Animals↗
PubMed1989

Failure of spermatozoa from T/t mice to fertilize in vitro is overcome by zona drilling.

Failure of epididymal spermatozoa from T/t mutant mice, but not from t/t individuals, to fertilize oocytes in vitro was partially overcome by opening a small aperture in the zona pellucida with acidified Tyrode's solution to permit direct access of the spermatozoon to the vitellus. This study provides a model system to evaluate requirements for successful zona drilling in the treatment of human infertility and further insights into the effects of the t complex on sperm fertility.

Animals↗
PubMed1989

Gamete processing in an environmental chamber: effect on in vitro fertilization outcome.

A study of mouse gamete processing for in vitro fertilization (IVF) under various conditions showed that it is necessary to control the atmosphere if the temperature is raised from 22 degrees C to 37 degrees C. The data suggest that maximum IVF success is attained by processing the gametes at 37 degrees C, under an atmosphere of 5% O2 and 5% CO2, and overlaying the medium with silicone oil.

Animals↗
PubMed1989

Smoking cessation and cardiovascular reactivity to stress.

Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) reactivity to mental arithmetic and deep knee bends were monitored in a sample of smokers prior to and 6 months following smoking cessation. There was no reduction in cardiovascular reactivity to either stressor following cessation. However, heightened pretreatment DBP and HR reactivity to mental arithmetic and SBP reactivity to deep knee bends were associated with relapse by the 6-month follow-up. Demographic and smoking history variables and pretreatment nicotine dependence were not associated with treatment outcome. Further exploration of cardiovascular reactivity to stress among smokers may elucidate the process of relapse.

Adult↗
PubMed1989

Increased human menopausal gonadotropin dose during the early follicular phase: effect on follicular recruitment and treatment outcome.

To investigate whether the provision of increased gonadotropins would enhance follicular recruitment and selection, women not responding (N = 18) to our standard clomiphene citrate (CC)-human menopausal gonadotropin (hMG) regimen were treated with increased hMG (treatment cycle II). Estradiol levels were higher in treatment cycle II and these differences were significant on days 8 and 9 (P less than or equal to 0.05 and P less than or equal to 0.03, respectively). On day 9, better follicular development was seen in cycle II (P less than or equal to 0.05). While none of the patients responded in cycle I, 10 of 18 responded in cycle II. Of the 10 responders, 2 conceived following in vitro fertilization and embryo placement. Increasing the dose of hMG improved the development of a cohort of follicles so that aspiration and possible pregnancy were achieved in women who were previously unresponsive to therapy.

Clomiphene↗
PubMed1989

Combined clomiphene citrate (CC) and human menopausal gonadotropins (hMG) in a fixed schedule for follicular recruitment during in vitro fertilization: effects on premature luteinizing hormone (LH) surges.

Recognizing the association between plasma progesterone (P) and an imminent LH surge, we investigated the frequency of P elevation in our stimulation protocol (clomiphene citrate-human menopausal gonadotropins). P was measured retrospectively on the day before, the day of, and the day after human chorionic gonadotropin hCG administration. The means +/- 2 standard deviations for P were as follows: day before hCG, 0.58 +/- 0.86; day of hCG, 0.64 +/- 0.56; and day after hCG, 1.47 +/- 1.22. Seven patients (8%) had P levels greater than 2 SD above the mean. Significant P elevations prior to hCG are infrequent with this protocol, and in the few patients with raised P a trend toward lowered fertilization was noted. The low incidence of P elevation may be secondary to the administration of hCG in a timely manner on the sixth day of estradiol (E2) rise.

Chorionic Gonadotropin↗
PubMed1989

Failed fertilization in human in vitro fertilization analyzed with the deoxyribonucleic acid-specific fluorochrome Hoechst 33342.

The degree and normality of nuclear maturation were assessed with the fluorochrome Hoechst 33342 in two groups of inseminated human oocytes that had failed to undergo fertilization. Group 1 consisted of 67 oocytes from 27 patients, each of whom had at least two other oocytes that had been fertilized and had cleaved. Group 2 consisted of 65 oocytes from 14 patients, none of whose oocytes had been fertilized. In group 1, 52.3% of the oocytes were found to be immature (germinal vesicle stage or metaphase-telophase I), whereas in group 2 only 26% were found to be immature. Thus oocyte nuclear immaturity was the major cause of fertilization failure when companion oocytes were fertilized. When no oocytes of a patient were fertilized, most oocytes were found to be mature, so other factors, such as sperm dysfunction or zona binding abnormalities, must account for most of the fertilization failure in this group of patients.

Benzimidazoles↗
PubMed1989

A program for matched, anonymous oocyte donation.

The authors' program for matched, anonymous oocyte donation has resulted in two successful pregnancies among the first eight oocyte recipients. All oocyte recipients to date have had ovarian failure or absence with premature ovarian failure the most common cause. All recipients were cycled on a program of incremental oral micronized estradiol and intramuscular progesterone-in-oil. Thirteen candidates for oocyte donation were screened to obtain 8 donors. One donor candidate was excluded because of her medical history. The psychological screening of 2 of the other donor candidates (who subsequently did not complete the donation cycle) revealed a primary motive of financial gain. In general, the psychological profiles of donor candidates revealed a high incidence of troubled families and either reproductive loss or loss of a parent. Ovarian stimulation of the donors followed our standard in vitro fertilization protocol. The recipients' exogenous steroid replacement continued until days 97 and 101, respectively, of the two gestations. Both pregnancies resulted in the delivery of normal singleton males--the first at 40 weeks, the second at 35 weeks.

Adult↗
PubMed1989

Efficacy of a gonadotropin-releasing hormone agonist in the treatment of uterine leiomyomata: long-term follow-up.

The authors employed a gonadotropin-releasing hormone agonist (GnRH-a) (D-His6-pro9-NET-GnRH) to treat 19 patients with symptomatic uterine leiomyomata, by daily subcutaneous injections (4 micrograms/kg) for 6 months. After therapy, patients were followed for 6 months without any therapy. Uterine volumes were measured by serial pelvic examinations and pelvic sonography. Measurements of serum estradiol, luteinizing hormone, and follicle-stimulating hormone were used to assess treatment response. Pituitary desensitization and hypoestrogenemia were achieved in all within 8 weeks, and in 18 of 19, hypoestrogenemia was maintained for the duration. Uterine volume at the conclusion of therapy (207.5 +/- 152.7 ml) was significantly reduced in all patients when compared with pretreatment sizes (420.8 +/- 276.4, P less than 0.05). Side effects included hot flashes (78%), vaginal dryness (32%), and transient frontal headaches (55%). All patients reported partial or complete relief from their symptomatic leiomyomata. Uterine volume at the conclusion of follow-up (345.4 +/- 195.7 ml) was greater than at the conclusion of therapy. Menses resumed in all patients within 4 to 8 weeks. In conclusion, GnRH-a therapy does not provide definitive therapy for symptomatic uterine leiomyomata but is effective in reducing the size of leiomyomata as a temporary measure. Gonadotropin-releasing hormone agonist therapy may be useful as an adjunct before myomectomy or hysterectomy and deserves further investigation.

Adult↗
PubMed1989

Independence of uniphasic and biphasic audiogenic seizure progressions in mice.

DBA/2J mice were monaurally or binaurally tested for susceptibility to sound-induced seizure. Two seconds following the beginning of running, one group of binaurally tested mice had acoustic stimulation interrupted for 15 s. These mice later seized when the stimulation was readministered. Their seizure progression closely resembled the behavior exhibited by noninterrupted binaurally stimulated mice and did not shift to the biphasic motor pattern of monaurally stimulated subjects. We conclude that the single burst of running of a binaurally tested mouse is qualitatively different from either of the two bursts of running exhibited by monaurally tested mice.

Acoustic Stimulation↗
PubMed1989

Monaural and binaural audiogenic seizures in mice.

The progression of sound-induced seizures was examined in unilaterally or bilaterally sensitized SJL/J mice tested either monaurally or binaurally. An unexpected right-side advantage for becoming susceptible to audiogenic seizure was observed. In addition, two distinct patterns of seizure progression were noted, a uniphasic sequence in which a single burst of running preceded the convulsion and a biphasic pattern with two such bursts. The biphasic progression is viewed to be the result of unilaterally initiated seizures and characteristically reached only a clonic level of severity. Uniphasic seizures are concluded to be the result of bilaterally initiated seizures and, when they occurred after more than 30 s of auditory stimulation, frequently reached a tonic level of intensity. The present results support the view that audiogenic seizures are characterized by precisely timed, sequential processes dependent upon the specific priming and test procedures employed.

Acoustic Stimulation↗
PubMed1988

Follicular aspiration: a comparison of an ultrasonic endovaginal transducer with fixed needle guide and other retrieval methods.

Ultrasonic techniques have been developed as alternatives to conventional laparoscopic aspiration for oocyte retrieval for in vitro fertilization (IVF). Given the advantages (less risk, lower cost, and greater patient acceptance) of these alternative techniques, it is appropriate to assess their efficacy compared with traditional laparoscopic retrieval. This article examines the recovery rate of oocytes and their subsequent fertilization rate with the use of an ultrasonic endovaginal transducer with fixed needle guide and compares these results with other retrieval methods. Comparisons were made between laparoscopic harvesting (n = 71, group I), ultrasonic transabdominal transvesical (n = 21, group II), and ultrasonic vaginal transducer (n = 76, group III). The data demonstrate comparable success using an ultrasonic endovaginal transducer with fixed needle guide. The authors believe this technique to be the procedure of choice for all routine oocyte retrievals during IVF treatment.

Female↗
PubMed1988

Pure follicle stimulating hormone does not enhance follicular recruitment in clomiphene citrate/gonadotropin combinations.

Patients beginning an in vitro fertilization (IVF) treatment cycle were prospectively randomized in double-blind fashion to receive either follicle-stimulating hormone (FSH) (Metrodin, Serono Laboratories, Inc., Randolph, MA) (n = 50) or human menopausal gonadotropin (hMG) (Pergonal, Serono) (n = 48) in combination with clomephene citrate (CC) (Serophene, Serono). There were no statistically significant differences in the percentage of dropped cycles, follicular response as measured by serum estradiol or ultrasound imaging, cycle day for hCG administration, number of oocytes recovered, fertilization and cleavage rates of the recovered oocytes, or the rate of clinical pregnancy establishment. In conclusion, there were no clinically important differences between FSH and hMG when combined with CC for enhanced follicular recruitment for IVF. Therefore, there is no apparent justification for the use of FSH in CC combination regimens, considering FSH's increased cost as compared with hMG.

Adult↗
PubMed1988

Relapse prevention versus broad spectrum treatment for smoking cessation: a comparison of efficacy.

The efficacy of a smoking cessation relapse prevention (RP) program, emphasizing cognitive-behavioral coping skills, was compared to that of a broad spectrum (BS) program, which emphasized behavioral skills. It was hypothesized that the RP program would be more effective in producing long-term abstinence, compared to the BS package. Abstinence rates validated by saliva thiocyanate and carbon monoxide, as well as self-report of smoking reduction, were measured at posttreatment, 3 and 6 months. No differences in posttreatment quit rates were found between the two groups, although both programs produced significantly higher quit rates than the wait-list control group. Contrary to prediction, the BS group produced marginally significantly greater abstinence at 3 months. No differences in abstinence were found at 6 months. Reduction in cigarette consumption was marginally significantly greater for the BS group at 3 and 6 months. Various mediators of treatment outcome were not found to influence success in quitting. There was a significant weight gain in those who quit.

Adult↗