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Biomedical subjects

W Thompson

Publications and source records attributed to W Thompson.

At least 37 records · Page 2Linked to original sources
PubMed1989

Genetic factors influencing lignin peroxidase activity in Phanerochaete chrysosporium ME446.

Haploid recombinant progeny of Phanerochaete chrysosporium ME446, genome compositions of which had been defined by RFLP-mapping, vary in their idiophasic behaviour. This allowed us to formulate a model of the sequence of idiophasic activities. One component of this variation, the amount of lignin peroxidase activity, is independent of the allele distributions of the lignin peroxidase gene clusters, but correlates with the allele distribution of another locus. This locus appears to control the spread of the lignin peroxidase-active state within the idiophasic mycelial mat and may be the mating-type locus. The successful determination of linkage relied on analysis of chromosome intervals rather than linkage to single markers; this approach should be generally useful for analysing quantitative characters by RFLP mapping.

Alleles↗
PubMed1989

Assessment of children's Type A behavior: relationship with negative behavioral characteristics and children and teacher demographic characteristics.

Thirty-two teachers rated Type A behavior, using Matthews Youth Test for Health, (MYTH) and negative characteristics of hyperactivity, negative peer relations, social withdrawal, and depression in 105 children, between the ages of 6 and 11, from lower to middle class Black and White families. Children's age, gender, race, and socioeconomic status (SES) and teachers' gender, grade taught, and years of teaching experience were not related to teachers' MYTH ratings. However, White teachers rated children higher on Type A behavior than Black teachers. Controlling for teacher race effects, MYTH total scores, rather than reflecting a global negative view of the child, showed a strong overlap with hyperactivity and were differentiated from social withdrawal and depression. The MYTH Impatience/Aggression factor was highly related to hyperactivity and negative peer interactions; the Competitiveness factor was associated with a lack of social withdrawal. The conclusions verify the multidimensional nature of children's Type A behavior pattern and the importance of rater demographic characteristics in the assessment of children's behavior.

Black or African American↗
PubMed1988

Ultrasound evaluation of cholelithiasis in the morbidly obese.

The ability to detect gallstones in the morbidly obese population has been questioned in recent literature. Utilizing state-of-the-art, real-time ultrasound equipment, 44 morbidly obese patients were examined prior to gastric exclusion surgery and concomitant cholecystectomy. The 91% sensitivity and 100% specificity of gallstone detection in this series matches the results for the general population. This study provided the unique opportunity to evaluate a large number (34) of negative ultrasound examinations, with subsequent surgical confirmation yielding a negative predictive value of 97%. This confirms the continued role of ultrasound in the evaluation of cholelithiasis.

Adolescent↗
PubMed1988

Conventional dose intravenous pulsatile GnRH therapy does not induce ovulation in polycystic ovarian disease.

The value of pulsatile GnRH therapy for induction of ovulation in patients with polycystic ovarian disease remains unclear. Intravenous pulsatile GnRH therapy was administered to a defined group of 5 patients with polycystic ovarian disease; all were infertile, had an LH:FSH ratio of greater than 2:1 on two or more occasions, and had multiple cysts on ovarian ultrasonography. All had failed to respond to clomiphene citrate. The 5 patients received increasing doses of GnRH (5-40 micrograms/pulse) continuously for up to 6 weeks. The response was evaluated by serial hormone levels and ovarian ultrasonography. During nine treatment periods no patient ovulated, and in only one did the LH:FSH ratio revert to normal. Four patients have subsequently had wedge resection of the ovaries and in each case the diagnosis of polycystic ovarian disease was confirmed. Pulsatile GnRH therapy was of no value in the management of this group of infertile patients with strictly defined polycystic ovarian disease.

Adult↗
PubMed1987

Effect of induced leucocyte migration on mammary cell morphology and milk component biosynthesis.

Effects of increasing milk somatic cell count on milk composition, milk component biosynthesis, and quantitative mammary histology were studied following intramammary infusion of sterile oyster glycogen in lactating ewes. Oyster glycogen had no direct effect on mammary tissue utilization of radiolabeled acetate. Intramammary infusion of oyster glycogen following each of six consecutive milkings in six lactating ewes increased mean milk somatic cell count (6-fold) and increased percent fat and protein but decreased milk lactose concentration. Quantity of damaged or nonsecretory epithelial cells was increased. Infused glands had increased concentrations of neutrophils (3-fold) and plasma cells (1.3-fold) in the subepithelial stroma and of neutrophils (2.7-fold) within the epithelial lining of alveoli. Infusion of oyster glycogen every 3 d for 30 d in four ewes elicited similar changes in milk somatic cell count and mammary histology. Loss of functional mammary cells associated with leucocytosis may explain lost milk production associated with increased milk somatic cell count.

Animals↗
PubMed1987

LHRH analogue therapy in infertile women with luteal phase defects.

Management of patients with unexplained (ovulatory) infertility is a difficult clinical problem. Some of these women exhibit repetitive luteal phase defects which may or may not respond to conventional treatment with anti-oestrogens or progesterone supplementation. Ablation of the defective cycles, by rendering the patients hypogonadotrophic, and then substituting induced cycles using exogenous gonadotrophins, was employed in 10 women who had been inexplicably infertile for up to 14 years. Over a trial period of six cycles good luteal phase progesterone profiles were achieved in all instances, but only two term pregnancies occurred. A further two patients conceived but one aborted and one had a tubal pregnancy. The results are discussed critically, regarding the importance of luteal phase defects in the aetiology of infertility and the conception rates which may occur even if no specific therapy is prescribed.

Adult↗
PubMed1979

Prenatal diagnosis of the Meckel syndrome.

Prenatal diagnosis of the Meckel syndrome was made at 20 weeks of gestation from the findings of a biparietal diameter smaller than expected for gestational age, a grossly raised amniotic fluid alphafetoprotein level and a rapid growth of foetal macrophages after 20 hours culture. Termination at 23 weeks of gestation resulted in a male foetus with an occipital encephalocele, microcephaly, polydactyly, and bilateral polycystic kidneys. This case report emphasies the importance for genetic counselling of delineating the Meckel syndrome from the multifactorial cases of neural tube defects, and also illustrates, at least in some cases, that the syndrome can be diagnosed in utero.

Abnormalities, Multiple↗
PubMed1979

The effects of post-ganglionic axotomy on selective synaptic connexions in the superior cervical ganglion of the guinea-pig.

Stimulation of preganglionic axons arising from different levels of the thoracic spinal cord causes different effects on end-organs supplied by the superior cervical ganglion (Langley, 1892; Nja & Purves, 1977a; Lichtman, Purves & Yip, 1979). For example, stimulation of the first thoracic ventral root (T1) causes pupillary dilatation and widening of the palpebral fissure; stimulation of T4, on the other hand, has little effect on the eye, even though axons arising from this level innervate about as many superior cervical ganglion cells as those from T1. Thus ganglion cell innervation is selective. (1) Three months after crushing the major post-ganglionic branches of the superior cervical ganglion this differential effectiveness is lost: T1 and T4 stimulation have approximately equal effects on the end-organs of the eye. (2) In normal animals, the cellular counterpart of selective end-organ effects is the innervation of each ganglion cell by a contiguous subset of the spinal segments that innervate the ganglion as a whole. One of these segments is usually dominant, the strength of innervation from adjacent segments falling off as a function of distance from the dominant one (Nja & Purves, 1977a). Intracellular recordings from ganglion cells 3 months after post-ganglionic axotomy showed that this selective pattern is re-established. (3) Since the innervation of ganglion cells appears normal, the abnormal end-organ responses after post-ganglionic axotomy suggest that ganglion cell axons are not limited to their original targets during peripheral re-innervation. This suggestion is supported by the finding that ganglion cells sending axons to different peripheral destinations via the second and third cervical spinal nerves were no longer distinguishable on the basis of their segmented inputs 3 months after post-ganglionic axotomy. (4) Similar results were obtained when the preganglionic cervical trunk was cut at the same time as the post-ganglionic axons were crushed; the pattern of end-organ responses was abnormal, whereas individual ganglion cells were re-innervated according to the rules of contiguity and segmental dominance. (5) These results indicate that ganglion cells do not undergo a compensatory change in the segmental innervation they receive when their axons regenerate to targets different from, or in addition to those they originally innervated, even when an entirely new set of ganglionic connexions is formed. This suggests that ganglion cells, or some aspect of their immediate environment, possess a permanent label that determines the segmental innervation they receive.

Animals↗
PubMed1979

Trisomy 20 mosaicism in amniotic fluid cell culture.

Chromosomal mosaicism in cultured amniotic fluid cells presents one of the most difficult problems in prenatal diagnosis in predicting the foetal phenotype. We present a case in which trisomy 20 mosaicism was diagnosed prenatally but not confirmed in the aborted foetus.

Abortion, Induced↗