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Biomedical subjects

M Gibson

Publications and source records attributed to M Gibson.

At least 145 records · Page 8Linked to original sources
PubMed1988

Bilateral transfer in mentally retarded children of ages 7 to 17 years.

The purpose of this study was to describe the effect of age on bilateral transfer of mildly mentally retarded girls (IQs of 70 to 90) after practice on a 45-rpm rotary pursuit task. Subjects were 96 girls from 7 to 17 yr. old. Each performed 14 trials on a rotary pursuit task (30-sec. trials, 10 sec. between trials), half performing the first seven trials with the nonpreferred hand, using the preferred hand on the next seven trials. The order was reversed for the remaining subjects. Nonsignificant differences between Trial 1 scores of the two groups indicated that the task was novel. Trial 1 scores of both groups were positively associated with age (r = 0.5). There was no transfer to preferred hand, with negative transfer occurring to the nonpreferred hand. It was concluded that, for the task used in this study, mentally retarded girls do not experience positive bilateral transfer as do normal, age-matched girls.

Adolescent↗
PubMed1988

A comparison of laparoscopy and laparotomy for the treatment of ectopic pregnancy.

A case-control method was used to examine differences in outcome between laparoscopy and laparotomy for the treatment of ectopic pregnancy. Cases and controls, 25 each, were matched by criteria selected to minimize differences in preoperative morbidity and technical difficulty. Patients treated laparoscopically had significantly shorter hospital stays (1.34 +/- 0.8 versus 3.92 +/- 1.1 days; mean +/- SD; P less than .01) and less operating time (77.5 +/- 26.1 versus 103.6 +/- 26.7 minutes; P less than .05). In addition, a laparoscopic approach resulted in a shorter convalescence (8.7 +/- 7.8 versus 25.7 +/- 16.2 days; P less than .01) and reduced postoperative analgesia requirements (0.84 +/- 2.3 versus 4.64 +/- 2.9 doses; P less than .01). We conclude that laparoscopic treatment of ectopic pregnancy is well tolerated by patients and, in comparison with laparotomy, requires fewer medical resources, thereby significantly reducing cost.

Convalescence↗
PubMed1988

Reproductive outcome after medical management of complicated pelvic inflammatory disease.

A significant proportion of women with PID will have their disease complicated by a TOC. We conclude that it is appropriate in women with this stage of PID to treat initially with clindamycin and an aminoglycoside. In addition, since more than half of the women will suffer reproductive difficulties, efforts to improve early diagnosis and therapy should continue. Based on our data, an early infertility evaluation is indicated in women wishing to conceive after complicated PID.

Aminoglycosides↗
PubMed1987

Ly-1 B helper cells in autoimmune "viable motheaten" mice.

Previous work has demonstrated that Ly-1 B cells from normal C57BL/6J mice help the response of B cell subsets to the 4-hydroxy-3-nitrophenylacetyl hapten (NP). This regulatory cell population, called BH, preferentially helps the expression of plaque-forming B cells which express a predominant set of serologically related determinants collectively known as the NPb idiotype family. The specificity of BH cell activity in the NP system is a reflection of NPb idiotype-specific BH cell surface receptors. Thus, BH cells recognize autologous (i.e., idiotype) antigens. Given these observations and previous associations of increased Ly-1 B cell frequency in autoimmune mice, it was hypothesized that autoreactive Ly-1 BH cells may be present in high frequencies and in an activated state in autoimmune mice. To test this hypothesis the immunologic activity of BH cells in autoimmune viable motheaten (mev/mev) mice was studied. It was determined that splenic BH cells are approximately 10 times more frequent in viable motheaten than normal mice. The fact that BH cells from viable motheaten mice are activated was suggested by the presence of NPb idiotype-specific BH replacing helper activity in sera or B cell supernatants from these autoimmune mice. The soluble helper activities constitutively produced in mev/mev splenic B cell cultures and detected in mev/mev serum were resolved into two moieties, an NPb idiotype-specific immunoglobulin and a nonimmunoglobulin lymphokine(s) fraction. Purified mev/mev B cell-derived B cell maturation factor could substitute for the lymphokine moiety in the NPb idiotype helper cell assay. These results suggest that at least two signals, anti-idiotype immunoglobulin and a late-acting B cell maturation factor, are required for BH-dependent helper activity. The relationships of these results to current concepts of B cell activation mechanisms and the possible association of Ly-1 BH cells with autoimmunity are discussed.

Animals↗
PubMed1987

The relationship of tubal infertility to barrier method and oral contraceptive use.

We studied past contraceptive use in 283 nulliparous infertile women who had a diagnosis of tubal adhesions or occlusion and in 3833 women admitted for delivery at seven collaborating hospitals from 1981 to 1983. The relative risk of tubal infertility associated with barrier contraceptive use or oral contraceptive use was calculated using multivariate logistic regression to control for confounding by region, age, religion, education, smoking, number of sexual partners, time since menarche, and use of other contraceptive methods. Women who had ever used barrier methods of contraception were at a significantly decreased risk of tubal infertility (relative risk = 0.6; 95% confidence limits, 0.5 and 0.8). When type of barrier method used for the longest time was evaluated, those who used the diaphragm or condoms plus spermicides were at lower risk than those who used condoms or spermicides alone. Overall, past use of oral contraceptives neither increased nor decreased a woman's risk of tubal infertility, but there was evidence that the association between oral contraceptives and tubal infertility may vary by the amount of estrogen and type of progestogen in the oral contraceptive used. We conclude that contraceptive users who use barrier methods that combine both a mechanical and chemical barrier, such as diaphragms, cervical caps, and condoms plus spermicides, have the clearest protection against tubal damage.

Adult↗
PubMed1987

The association between smoking and female infertility as influenced by cause of the infertility.

Smoking histories were compared in 901 women with infertility of different types and 1264 women admitted for delivery at seven collaborating hospitals. The relative risk for infertility associated with cigarette smoking prior to the infertility diagnosis for nulliparous cases or first live birth for controls was calculated using a multivariate logistic-regression model to control for potential confounding factors, including center, age, religion, education, number of sexual partners, and contraceptive use. The adjusted risk for infertility attributed primarily to cervical factor (n = 96) was 1.7 (P = 0.04), to tubal disease unrelated to endometriosis (n = 225) was 1.6 (P = 0.009), to ovulatory factor (n = 389) was 1.0 (not significant [NS]), and to endometriosis (n = 191) was 0.9 (NS). The authors conclude that cigarette smoking is significantly associated only with certain types of primary female infertility.

Adult↗
PubMed1987

Norethindrone inhibition of testosterone secretion by an ovarian Sertoli-Leydig cell tumor.

A woman with severe hyperandrogenemia and virilization was found to have a fall in serum testosterone (T) concentration while taking an oral contraceptive containing norethindrone (500 vs. 164 ng/dL). Subsequent surgical exploration revealed an ovarian Sertoli-Leydig cell tumor. In vitro, the tumor secreted T (mean, 1.88 ng/mg X 4 h). hCG did not stimulate T secretion. In addition, norethindrone inhibited T secretion (0.33 ng/mg X 4 h). We conclude that norethindrone directly suppressed T production by the Sertoli-Leydig cell tumor.

Adult↗
PubMed1987

Circadian rhythmicity restored by neural transplant. Immunocytochemical characterization of the graft and its integration with the host brain.

It is well established that overt circadian rhythms are permanently disrupted following lesions of the hamster hypothalamic suprachiasmatic nucleus (SCN). In the present study, we show that implantations of brain grafts containing the fetal SCN reestablish circadian rhythms of locomotor activity in adult hamsters previously made arrhythmic by SCN lesions. The restoration of free-running rhythms in conditions of constant darkness is correlated with the presence in the graft of neuropeptides normally present in the SCN of unlesioned hamsters, including vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and vasopressin (VP). In several recipients, grafts were found to receive retinal input, and appeared to send efferents into the host brain. Not all functions of the SCN were reinstated by the graft: animals with restored locomotor rhythms did not show gonadal regression in the absence of light, and failed to synchronize (entrain) to light intensities to which SCN-intact animals responded.

Animals↗
PubMed1987

Diagnostic strategies of fifth year medical students in a neurological case. The importance of the first hypothesis.

The problem-solving strategies of fifth year medical students were studied using two simulated cases. One of these cases involved a neurological problem which was unfamiliar to the students. With the use of stimulated recall the study looked at the origin of the first hypothesis. The symptoms given by the patient did not trigger an appropriate hierarchy of questions and the students resorted to problem-solving techniques, such as drawing on commonsense. In some cases they matched symptoms against clinical cases they had seen previously. Recall from lectures was used occasionally. Instead of rational methods of hypothesis generation, they were most likely to be influenced by recent clinical exposures. Students having identical experiences may have had differing perceptions of these exposures. As a result, their early hypothesis formation showed marked individual variation. These findings need to be considered in the light of how students learn and the content of the teaching that is meaningful to them.

Curriculum↗
PubMed1986

The relation of endometriosis to menstrual characteristics, smoking, and exercise.

We compared menstrual characteristics and constitutional factors in 268 white women with primary infertility due to endometriosis and in 3,794 white women admitted for delivery at seven collaborating hospitals from 1981 to 1983. Adjusting for confounding factors, including location, age, religion, and education, women with short-cycle lengths (less than or equal to 27 days) and longer flow (greater than or equal to one week) had more than double the risk for endometriosis compared with women with longer cycle lengths and shorter duration of flow. There was a trend for increasing risk for endometriosis to be associated with increasing menstrual pain. Adjusting for these menstrual characteristics, we found decreased risk for endometriosis associated with smoking or exercise that was largely confined to women who began either habit at an early age and were heavier smokers or more strenuous exercisers. We conclude that risk for endometriosis may relate to menstrual factors that predispose to greater pelvic contamination with menstrual products and to constitutional factors that influence endogenous hormonal levels.

Adolescent↗
PubMed1986

A trial of flunarizine in the treatment of Duchenne muscular dystrophy.

Twenty-seven boys with Duchenne muscular dystrophy (DMD) entered a double-blind controlled trial of treatment with the calcium antagonist flunarizine. They were matched for age and disability. At monthly intervals, muscle power, functional ability, locomotor score, contractures, and forced vital capacity were measured by a team not involved in clinical care. Over a period of 1 year, flunarizine in a dose of up to 0.25 mg/kg/day had no effect on the clinical course of the disease.

Adolescent↗
PubMed1986

Effect of prostaglandin synthesis inhibition on human corpus luteum function.

The hypothesis that human luteolysis is mediated by prostaglandin F2 alpha was initially tested through placebo-controlled observations of the effect of a single dose of ibuprofen on progesterone and luteinizing hormone levels late in the luteal phase in normal human subjects. Falling levels of progesterone at rest, not significantly attenuated by ibuprofen, did not support, and falling progesterone/luteinizing hormone ratios at rest, significantly attenuated by ibuprofen, did support this hypothesis. The pulsatile nature of progesterone levels in the human was confirmed in this study.

Corpus Luteum↗
PubMed1986

Percentage body fat and prevalence of obesity in a UK offshore population.

1. Body-weight, body height and skinfold measurements were taken in 419 adult males working in the UK offshore oil industry. Percentage body fat was estimated from skinfold thicknesses and the Quetelet index (weight:height) determined. 2. The prevalence of overweightness, assessed from the Quetelet index, in the age groups 20-29, 30-39 and 40-49 years was 31.6, 50.0 and 66.2% respectively. The Office of Population Census and Surveys (1981) showed that for age-matched groups, the incidence of overweightness in an onshore population was 26, 40 and 50% respectively. 3. The percentage body fat for each respective age group was greater than that reported for an age-matched onshore population. 4. The Quetelet index was significantly related to body fat (r 0.765, P less than 0.0001) and poorly correlated with height, thus this weight:height relation may be utilized in the assessment of overweightness in offshore personnel. 5. In conclusion it appears that the offshore population had a higher percentage body fat than their onshore peers and that the prevalence of overweightness was also greater.

Adipose Tissue↗
PubMed1986

Infectious causes of recurrent pregnancy loss.

Current knowledge supports the view that nonviral organisms may be responsible for repeated pregnancy wastage through chronic or recurrent occupancy in the maternal reproductive tract. However, two forms of evidence that would establish more clearly such a role lack for all of the organisms presented: recovery of the same organism from the products of conception in successive pregnancy losses, and demonstration of improved pregnancy outcome following specific treatment in a randomized prospective controlled trial. While acquisition of such data is scientifically justified, the necessary study designs may be viewed as unethical if the body of information derived from circumstantial cases and therapeutic trials using historical controls only continues to shape clinical opinion. Further confirmation of a specific role in pregnancy wastage for any of these organisms eventually will have to address the mysterious discrepancy between the prevalence of colonization and the incidence of sporadic and recurrent abortion purportedly due to the organism.

Abortion, Habitual↗
PubMed1986

Bilateral transfer across ages 7 to 17 years.

The purpose of this experiment was to determine the effect of age on bilateral transfer. 96 girls, ages 7 to 17 yr., performed 14 trials on a rotary pursuit tracking task (45 rpm, 30-sec. trials, 10 sec. between trials). Half of the subjects performed the first seven trials with the preferred hand, using the nonpreferred hand on the subsequent seven trials. The order was reversed for the other subjects. There were no significant differences between groups in initial scores or in increases in time on target over the first seven trials, supporting the hypothesis that this was a novel task. There was an increase in time on target across ages and age influenced bilateral transfer, with older girls profiting more from the other-hand practice. Transfer was greater from preferred to nonpreferred than the reverse.

Adolescent↗
PubMed1986

Early recognition of ectopic pregnancy in an infertility population.

On an infertility service, 170 patients were evaluated for possible ectopic pregnancy using tests for beta-human chorionic gonadotropin levels, ultrasound, and clinical examination. Thirty-four (20%) of those evaluated underwent laparoscopy, of whom 31 (91%) were found to have ectopic pregnancies. Only three of the ectopic pregnancies were ruptured; only two women had significant hemoperitoneum and only two required transfusion. Subsequent intrauterine pregnancy occurred in 5 of 11 patients who underwent salpingectomy (45%) and in 1 of 15 patients who underwent salpingotomy (7%). There were no subsequent pregnancies in five patients after expression of the ectopic from the tube. Early intervention in an infertile population decreases morbidity and may favor conservative tubal surgery, although our series could not confirm the benefits of such surgery.

Chorionic Gonadotropin↗