Search PubMed⌕ Search

Biomedical subjects

W Thompson

Publications and source records attributed to W Thompson.

At least 127 records · Page 7Linked to original sources
PubMed1981

Serum and hair concentrations of copper during pregnancy.

Serum and hair concentration of copper were measured in 28 nonpregnant women and 60 pregnant women at 20 to 22 wk gestation (2nd trimester), 36 to 37 wk gestation (3rd trimester), and 3 days postpartum. The serum copper concentration in pregnant women was approximately twice (1.71 to 1.79 micrograms/ml) the normal nonpregnant values (0.98 micrograms/ml). These high levels persisted throughout pregnancy and early postpartum. The mean concentration of serum copper in maternal serum was about five times those in umbilical cord blood (0.33 microgram/ml) and a strong relationship was noted between maternal and cord copper concentration. Hair copper levels were similar in pregnant and nonpregnant subjects. No significant relationship was noted between serum and hair copper concentrations. Serum copper levels were higher and hair copper concentration was lower in primigravida. Previous history of oral contraceptive usage and alcohol intake during pregnancy had no effect on serum or hair copper levels. The effect of smoking was not consistent and showed a significant lowering effect on serum copper values only in the 2nd trimester. The 3rd trimester levels of hair copper and serum copper demonstrated a significant correlation with neonatal weight and head circumference, respectively. Further studies are indicated to understand the implication of such changes in copper metabolism.

Adult↗
PubMed1981

Riboflavin status during pregnancy.

The riboflavin status of 20 nonpregnant and 60 pregnant women (in the 2nd trimester, 3rd trimester, and early postpartum) was determined by the erythrocyte glutathione reductase activation test. None of the nonpregnant subjects but 26 pregnant subjects (21.7% in the 2nd trimester, 20.8% in the 3rd trimester, and 29.6% in early postpartum) had an activity coefficient greater than 1.20, indicative of biochemical deficiency of riboflavin. The deficiency developed at any of the three stages of pregnancy under study. Follow-up of individual cases revealed no progressive deterioration in riboflavin nutriture with advancement of pregnancy. The mean intake of riboflavin was higher than the recommended intake and revealed a significant negative correlation with activity coefficient values at the 3rd trimester. No significant correlation of riboflavin status with the outcome of pregnancy was noted. The effect of numbers of previous pregnancies, history of oral contraceptive usage, smoking, and alcohol showed no consistent effect on the percentage incidence of deficiency at all the three periods.

Adolescent↗
PubMed1981

Zinc concentration in hair and serum of pregnant women in Belfast.

Serum and hair levels of zinc were estimated in 28 nonpregnant women and 60 pregnant women at 20 to 22 wk of gestation (2nd trimester), 36 to 37 wk of gestation (3rd trimester), and 3 days postpartum. The mean serum zinc concentration was significantly lower in pregnant subjects compared to the nonpregnant and showed a continuous significant decline with increasing duration of pregnancy. Mean hair concentration in the various stages of study of pregnant women and nonpregnant subjects were comparable. However, a progressive decrease in hair zinc concentration was noted with advancing pregnancy; the decline between 2nd and 3rd trimester was statistically significant. Mean serum zinc concentration in umbilical cord blood was approximately twice that in maternal blood. Smoking had no effect on zinc concentration, while the effect of alcohol and parity was inconsistent. Oral contraceptive usage before conception appeared to lower hair zinc concentration and increase serum zinc concentration during pregnancy. Two subjects had spontaneous abortion and these had serum zinc in the lower range and hair zinc values in the higher range. The remaining 58 subjects gave birth to normal neonates weighing 2500 to 4500 g. The study revealed that zinc nutrition of the majority of the expectant mothers was adequate for normal growth and development of fetus. The possible cause and implication of observed changes in zinc metabolism are discussed.

Adolescent↗
PubMed1981

Re-innervation of ganglia transplanted to the neck from different levels of the guinea-pig sympathetic chain.

Thoracic and lumbar sympathetic ganglia from donor guinea-pigs were transplanted to the bed of an excised superior cervical ganglion in host animals. Homotopic transplants of superior cervical ganglia served as controls. In this way the same set of preganglionic axons (the cervical sympathetic trunk) was confronted with ganglia from different levels of the sympathetic chain. Re-innervation of the transplants was studied after 3-5 months. 1. Neurones in ganglia transplanted from different levels of the sympathetic chain were re-innervated to about the same over-all degree by the preganglionic axons of the host's cervical sympathetic trunk. Thus, the mean amplitude of post-synaptic potentials, the estimated number of innervating axons, and the number of spinal segments providing innervation to each neurone were similar in transplanted thoracic, lumbar and superior cervical ganglion cells. 2. Neurones in transplanted mid-thoracic ganglia, however, were re-innervated more frequently, and more strongly, by axons arising from more caudal thoracic segments than neurones in transplanted superior cervical ganglia. Stimulation of axons arising from the fourth thoracic spinal segment (T4), for example, elicited post-synaptic potentials that on average were twice as large in transplanted fifth thoracic ganglion cells as in transplanted superior cervical ganglion cells; conversely, axons arising from T1 re-innervated neurones in the superior cervical ganglion about 2-3 times more effectively than fifth thoracic ganglion cells. This difference in the re-innervation of the fifth thoracic and the superior cervical ganglion is in the same direction as (although less pronounced than) the normal difference in the segmental innervation of these ganglia. 3. Transplanted lumbar ganglia were also re-innervated more effectively by relatively caudal segments compared to re-innervated cervical ganglia, but this difference was no greater than that observed for transplanted thoracic ganglia. 4. We conclude that preganglionic axons can distinguish (or be distinguished by) ganglia derived from different levels of the sympathetic chain. Our findings are consistent with the view that ganglion cells have some permanent property that biases the innervation they receive.

Animals↗
PubMed1980

The fate of foreign endplates in cross-innervated rat soleus muscle.

After transplantation of the superficial fibular and the medial plantar nerve to neighbouring sites in the proximal region of adult rat soleus muscles many muscle fibres were initially innervated by axons in both foreign nerves after resection of the original soleus nerve. The foreign endplates were formed at ectopic sites and were often separately located on individual muscle fibres. After 3-4 weeks many endplates had been eliminated and most muscle fibres were innervated by only a single foreign axon. Many muscle fibres still had multiple esterase-staining endplate sites in the region innervated by the foreign nerve. On examination by electronmicroscopy, some of these sites were seen to have lost their presynaptic terminal while the postsynaptic structure of the endplate remained intact. Other sites were only partially occupied by motor axon terminals. On each muscle fibre there was always at least one fully occupied endplate region. In some instances separate endplate sites on the same muscle fibre were innervated by branches of the same motor axon. We conclude that the elimination of endplates is due to a competitive interaction between motor axons innervating the same muscle fibre. Morphologically, the elimination of functional endplates is caused by a retraction of nerve terminals from the postsynaptic site.

Acetylcholinesterase↗
PubMed1980

Contrast-induced acute renal failure: persistent nephrogram as clue to early detection.

Renal failure from urographic contrast media is a serious potential hazard of excretory urography and is usually recognized by the clinician 24--48 hr after the procedure. The association of an abnormally increasing nephrogram with development of oliguric renal failure in children was described in 1969, but in 112 subsequent reported cases of contrast-induced renal failure, a persistent nephrographic pattern was described only once. With special attention to the abnormally persistent nephrogram, we were able to detect nine cases of contrast-induced renal failure after excretory urography. Two of these cases are discussed in detail and pertinent data on the other seven are presented.

Acute Kidney Injury↗
PubMed1980

Vitamin B6 status during pregnancy.

Nutritional status of vitamin B6 was investigated in 20 non-pregnant and 60 pregnant women (in the second trimester, third trimester and early postpartum) by determining the erythrocyte glutamic-pyruvic transaminase (EGPT) index. An EGPT index of greater than 1.15 indicative of vitamin B6 deficiency was noted in 30.0% non-pregnant subjects and in 50.0, 53.1 and 44.4% of pregnant subjects in second trimester, third trimester and postpartum periods, respectively. The deficiency developed at any of the three stages of pregnancy under study. Follow up of individual cases revealed no progressive deterioration in vitamin B6 nutrition with advancement of pregnancy. EGPT index values showed large individual variation during pregnancy. The mean intake of vitamin B6 was lower than the recommended and only 5.9% of subjects reported consuming greater than or equal to 2.5 mg vitamin B6/day. There was no significant correlation between biochemical parameters and vitamin B6 intake/day or vitamin B6/100 g protein/day. No significant relationships were observed between vitamin B6 status and the outcome of pregnancy, or anthropometric measures of neonates.

Adolescent↗
PubMed1980

Thiamin status during pregnancy.

Thiamin status of 20 nonpregnant women and 60 pregnant women was assessed. Of the 60 pregnant women, only 49 and 25 were examined for the biochemical thiamin status in the 3rd trimester and postpartum period respectively. Thirty per cent of nonpregnant women and 28 to 39 per cent of pregnant mothers (in either the 2nd trimester, 3rd trimester, or postpartum phase of pregnancy) had a deficient thiamin status with the thiamin pyrophosphate effect (TPP effect) greater than 20 per cent. None of the pregnant subject were deficient in all the three periods. Follow up of the pregnant subjects in the 2nd trimester, 3rd trimester and postpartum period revealed that the deficiency was not necessarily established in the early pregnancy nor was aggravated with the progress of pregnancy. Thiamine intake was over 2/3 of the recommended in all the pregnant subjects and revealed no significant correlation with the biochemical indices. A history of oral contraceptive usage before conception had no significant effect on the incidence of deficiency in the 2nd or 3rd trimester. The occurrence of deficient thiamin status demonstrated an increase with number of previous pregnancies. No correlation was noted between the vitamin B1 status and anthropometric measurements of neonates.

Adolescent↗
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↗