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Biomedical subjects

L M Wilson

Publications and source records attributed to L M Wilson.

At least 55 records · Page 3Linked to original sources
PubMed1988

Fertilization of human oocytes in relation to varying delay before insemination.

Fertilization and pregnancy rates in an in vitro fertilization and embryo transfer program were studied after a range of insemination times of between 1 and 26 hours after oocyte recovery. There was no significant variation in fertilization rate across this range. The pregnancy rate showed no significant variation for insemination between 3 and 16 hours after aspiration. However, it was disappointing at 2 hours (3%), and no pregnancies were achieved from the nine patients whose ova were inseminated 20 or more hours after aspiration. It is concluded that mature oocytes can be inseminated in vitro at any time between 3 and 16 hours after aspiration and still retain the same potential to produce a pregnancy.

Female↗
PubMed1988

Effect of the trichothecene deoxynivalenol on brain biogenic monoamines concentrations in rats and chickens.

Male Sprague-Dawley rats (180 g) and 28-day-old Single Comb White Leghorn Cockerels (300 g) were orally dosed with deoxynivalenol (DON) at 2.5 mg kg-1 body weight. In the first experiment, whole brains were collected at 2, 6, 12, 24 and 48 hours after the toxin treatment and analyzed for brain biogenic monoamines by high-performance liquid chromatography with electrochemical detection. Although several interesting trends were observed, DON did not influence whole brain concentrations of monoamine neurotransmitters or their metabolites in either species, at any time. In a second experiment, brains were collected 24 hours postdosing, dissected into 5 brain regions (pons and medulla oblongata, cerebellum, hypothalamus, hippocampus and cerebral cortex), and analyzed. DON treatment resulted in significantly elevated concentrations of serotonin (HT) and 5-hydroxyindole-3-acetic acid (HIAA) in all brain regions of the rat. However, this was not seen in poultry, where DON treatment resulted in a decrease in norepinephrine (NE) in the hypothalamus and hippocampus, and a decrease in dopamine (DA) in the pons and medulla oblongata region. These results suggest that DON influences brain biogenic amine metabolism, and that there may be intraspecies differences in the central effects of this mycotoxin.

Animals↗
PubMed1988

Effect of T-2 toxin on brain biogenic monoamines in rats and chickens.

Two experiments were conducted to determine the effect of T-2 toxin on brain biogenic monoamines and their metabolites. Male rats (180 g) and cockerels (28 day, 300 g) were orally dosed with T-2 toxin at 2.5 mg kg-1 body weight. In the first experiment, whole brains were collected 2, 6, 12, 24 and 48 h postdosing and analyzed for monoamines by high performance liquid chromatography with electro-chemical detection. T-2 toxin did not influence whole brain concentrations of monoamines in either species. In the second experiment, brains were collected 24 h postdosing, dissected into five brain regions, and analyzed for monoamines. T-2 toxin treatment resulted in increased serotonin and 5-hydroxy-3-indoleacetic acid in all brain regions of the rat. However, this was not seen in poultry where T-2 toxin treatment resulted in an increase in 5-hydroxy-3-indoleacetic acid, no alteration in serotonin concentration and a decrease in regional norepinephrine and dopamine concentrations. These results suggest that T-2 toxin influences brain biogenic amine metabolism and that there is an intraspecies difference in the central effects of this mycotoxin.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1987

Results using medium supplemented with either fresh or frozen stored serum in human in vitro fertilization.

This study retrospectively compared the success of in vitro fertilization (IVF) among patients whose gametes had been incubated either in medium supplemented with freshly prepared pooled serum (331 cases) or in pooled serum which had been stored at -20 degrees C prior to use (728 cases). Frozen stored serum was as effective as fresh serum with regard to the proportion of oocytes which fertilized and embryos which implanted and was not associated with any increased incidence of fetal loss during postimplantation development.

Blood Physiological Phenomena↗
PubMed1987

Incidence of cardiac septal defects in children with Wilms' tumour and other malignant diseases.

In a population-based series of 8045 children with malignant neoplasms in Great Britain, the incidence of septal defects was 0.40%. The high rate of 19% in Down's syndrome children and the overall rate of 0.28% in children without Down's syndrome were both comparable with rates found in previous large prospective studies. The incidence of septal defects in children with Wilms' tumour was 1.82%, greater than 10 times that for non-Down's children with other neoplasms. The presence of this association in Wilms' tumour patients with and without aniridia and the recent finding of a loss of heterozygosity in chromosome 11 in many Wilms' tumours taken from patients without aniridia suggest the possibility of a link between Wilms' tumour, some septal defects and chromosomal abnormalities.

Adolescent↗
PubMed1986

Immunizations against infectious diseases and childhood cancers.

A study based upon an unusually large series of childhood cancers and matched controls found a significant deficit of case/control pairs in which the cancer case had fewer immunizations against infectious diseases than the matched control. All types of immunizations and cancers were affected but the case/control differences were more pronounced for older cases with late immunizations than for younger cases with early immunizations, and more pronounced for solid tumours than leukaemia. Therefore there may be immune system responses to immunizations (or simulated infections) which make it difficult for small clones of cancer cells to enlarge and are more successful in preventing localised tumours in adolescents than childhood leukaemias.

Adolescent↗
PubMed1986

A formula for scoring human embryo growth rates in in vitro fertilization: its value in predicting pregnancy and in comparison with visual estimates of embryo quality.

Two systems for measuring embryo development in vitro were evaluated. One was a 1-4 scale based on a subjective evaluation of embryo quality (EQ) from microscopic appearance. In addition, a formula for scoring embryo growth rate in vitro was developed. The embryo development rating (EDR) was based on the ratio between the time at which embryos were observed at a particular stage after insemination and the time at which they would be expected to reach that stage in a hypothetical "ideal" growth rate with a cell cycle length of 11.9 hr. Using this scoring system, "normally" growing embryos scored 100. This approach was aimed at partially normalizing the data and allowed all embryos to be analyzed similarly regardless of the time of observation. Analysis of 1539 embryo replacements resulting in 232 clinical pregnancies showed that both EDR and embryo-quality scores were of value in predicting success, with clinical pregnancy most likely to eventuate from a combination of moderate to good EQ scores (2-4) coupled with average or above-average growth rates (EDR scores from 90 to 129). Poor-quality and very slowly or very rapidly growing embryos were underrepresented in cycles that proceeded to pregnancy. These inferences were based on all embryos transferred (mean, 2.73 per transfer cycle), and they were substantiated by an analysis of 33 pregnancies resulting from replacement of a single embryo and from 18 pregnancies in which all embryos scored the same with both systems. EQ and EDR were significantly associated with each other and together provide a valuable guide in predicting pregnancy, in selecting embryos for freezing, and in monitoring day-to-day performance in the in vitro fertilization (IVF) program.

Embryo Transfer↗
PubMed1985

Thermal preference behavior of genetically obese (ob/ob) and genetically lean (+/?) mice.

Chronically lower colonic temperatures (TcS) of genetically-obese (ob/ob) mice at ambient temperatures below thermoneutrality have led to speculation that these mutants regulate a lowered thermal setpoint relative to lean mice. Previous experiments, however, have not provided an opportunity for obese mice to exhibit compensatory thermoregulatory behaviors which might reinstate normal body temperature. In the present experiment, adult obese and lean (+/?) mice were tested at room temperature (25 degrees C) on a copper bar, thermal gradient to determine what temperatures they would select and what effect their selection would have on their TcS. The data revealed that ob/obs were more frequently observed within 25-35 degrees C locales than were lean controls, which spent more time in the below-25 degrees C zone (p less than 0.005). Ob/obs also raised their TcS to pretest values of leans' TcS, although ob/obs' TcS remained significantly lower than those of leans at the conclusion of testing. These data suggest that the hypothermia exhibited by the ob/ob may reflect both the absence of the opportunity to behaviorally thermoregulate and a genetic defect in thermogenesis.

Animals↗
PubMed1982

Prenatal factors in the aetiology of testicular cancer: an epidemiological study of childhood testicular cancer deaths in Great Britain, 1953-73.

A case-control study is reported based on 87 deaths from testicular cancer that occurred in children in Great Britain 1953-73. Factors that significantly increased relative risk were tuberculosis of the mother during the index pregnancy and maternal epilepsy; factors that increased risk but not significantly were hyperemesis in the index pregnancy, a maternal history of stillbirths, and hernia and genitourinary defects in the child. Cryptorchidism was not studied. The available evidence suggests that prenatal determinants of testicular cancer in adults are also determinants of testicular cancer in childhood. The incidence and mortality from this disease are not increasing among children in Britain and other countries, whereas there is an increasing trend in young adults in several developed countries. Probably, therefore, the secular increase in the rates of young adult testicular cancer is due to factors that affect adults but not children, the hence are likely to be postnatal.

Abortion, Spontaneous↗
PubMed1981

Suckling: developmental indicator of genetic obesity in mice.

The Bar Harbor obese-hyperglycemic mouse (ob/ob) characteristically develops its obese phenotype during the postweaning period, when access to food is unrestricted and its behavioral phenotype of hyperphagia appears. In the present study suckling behavior (viz., nipple attachment latencies and total suckling time) of lean and preobese mouse pups, derived from matings of heterozygous lean patients, was measured in either fed or fasted conditions from 6 to 21 days postpartum on anesthetized dams. Twenty-hour milk deprivation selectively channeled pup activity into suckling for both preobese and lean mice, although, in general, preobese mice nipple-attached sooner and suckled longer than leans. In particular, fed preobese pups suckled longer than fed lean pups from 18 days on, providing a preweaning behavioral indicant of a genetic tendency to obesity when environmental constraints on overeating are minimized.

Age Factors↗
PubMed1979

Nephroblastoma: treatment during 1970-3 and the effect on survival of inclusion in the first MRC trial.

In 1970-3 313 children were diagnosed as having nephroblastoma in Great Britain. From the start of the first Medical Research Council nephroblastoma study in October 1970 until the end of 1973, 98 children (57% of all eligible children) were included in the trial. Of the 313 children, 288 (92%) had a nephrectomy, 248 (79%) received a course of radiotherapy, and 267 (85%) were given at least four days' chemotherapy. The three-year survival rate was 58%; the rate among children in the trial (77%) was significantly better than that among children who were eligible for the trial but not included (58%). Children who had nephrectomies at specialised children's and teaching hospitals had a higher survival rate than those treated elsewhere. All children with nephroblastoma should be treated according to well-defined protocols which take into account the age of the child and the stage of the tumour and include a full course of maintenance chemotherapy.

Adolescent↗