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Biomedical subjects

A Taylor

Publications and source records attributed to A Taylor.

At least 541 records · Page 30Linked to original sources
PubMed1990

Dietary energy restriction decreases ex vivo spleen prostaglandin E2 synthesis in Emory mice.

Dietary energy restriction prolongs life-span and enhances immune responsiveness by mechanisms yet to be elucidated. Prostaglandin E2 (PGE2) has a suppressive effect on several parameters of cell-mediated immunity. The effect of energy restriction on splenic PGE2 synthesis in Emory mice was studied. Weanling Emory mice were fed an energy-restricted (R, 71.3 kcal/wk) or control (NR, 90.8 kcal/wk) diet for 11-14 mo. The final weights of R mice were 66% of weights of NR mice (27 +/- 1 vs. 41 +/- 1 g for females and 34 +/- 1 vs. 51 +/- 1 g for males, for R and NR, respectively). NR female mice had higher spleen PGE2 levels than NR male mice (698 +/- 64 vs. 522 +/- 47 ng/mg protein, P = 0.03). In all cases, R mice had less PGE2 than NR mice, and there was no sex-related difference in R mice (418 +/- 39 vs. 698 +/- 64 ng/mg protein in R and NR females, P = 0.001 and 416 +/- 39 vs. 522 +/- 47 ng/mg protein in R and NR males, P = .009). Total spleen PGE2 was also reduced significantly by energy restriction; however, gender differences were not observed in total spleen PGE2 level of NR mice. Thus, 1) spleens from female mice synthesize more PGE2/mg protein than do those from male mice, and 2) dietary energy restriction reduces ex vivo spleen PGE2 synthesis. This phenomenon may contribute to the observed immunostimulatory effect of dietary energy restriction in mice.

Aging↗
PubMed1990

Comparison of Tc-99m MAG3 and Tc-99m DTPA in renal transplant patients with impaired renal function.

Tc-99m mercaptoacetyltriglycine (MAG3) is a new Tc-99m renal agent that compares favorably to I-131 Hippuran in animal models, normal volunteers, and patients. Based on the fact that Tc-99m MAG3 has a much more rapid clearance than Tc-99m DTPA and a smaller volume of distribution, it was postulated that the image quality of Tc-99m MAG3 studies should be superior to scans obtained using Tc-99m DTPA, particularly in patients with impaired renal function. To test this hypothesis, Tc-99m DTPA and MAG3 images were obtained in three transplant patients during periods of stable but impaired renal function. In one study, the Tc-99m DTPA study was potentially misleading, whereas the Tc-99m MAG3 examination assessed the clinical situation correctly. In all three cases, the Tc-99m MAG3 images were superior.

Adult↗
PubMed1990

Use of sodium aurothiomalate during lactation.

The report concerns a mother who breast fed her infant whilst receiving sodium aurothiomalate for the treatment of rheumatoid arthritis. The milk:serum concentration ratio was not constant, reflecting the non-concurrence of the concentration-time profiles of gold in milk and maternal serum after i.m. injection. Gold was detected in the infant's serum. Calculations indicate that the weight-adjusted dose to the infant exceeded that received by the mother.

Adult↗
PubMed1990

Permeability of the human placenta in vivo to four non-metabolized hydrophilic molecules.

1. Permeability of the human placenta to four permeants of different molecular size was measured at Caesarean section in seven normal full-term pregnancies. 2. Placental clearance for mannitol was 8.7 +/- 1.1 ml min-1 (mean +/- S.E.M.), lactulose 6.3 +/- 0.8, chromium ethylenediaminetetraacetic acid (CrEDTA) 3.7 +/- 0.5, and inulin 0.98 +/- 0.1. 3. The permeability data were analysed in terms of restricted diffusion through 'notional' water-filled pores and found to be incompatible with a single population of uniform pores.

Adult↗
PubMed1990

Raised dopamine metabolites in a case of malignant paraganglioma.

This paper describes the case of a malignant retroperitoneal paraganglioma with extensive metastases. The patient presented with a supraclavicular mass and an absence of hypertension. Exclusively raised dopamine metabolites were detected which may be a marker of a malignant process and account for the lack of hypertension.

Adult↗
PubMed1990

Effect of hypercalcemia on the anion gap.

It has been assumed, but not documented, that hypercalcemia induces an appreciable reduction in the serum anion gap (AG) because it represents an increase in the level of unmeasured cations. To test this question, we retrospectively compared the data of 59 hypercalcemic patients with malignancy [group 1, serum Ca 13.3 +/- SE 0.3 mg/dl] with those of 108 patients whose hypercalcemia was of parathyroid origin (group 2, serum Ca 12.1 +/- 0.1 mg/dl), and those of 51 control subjects (group 3, serum Ca 9.5 +/- 0.1 mg/dl). The AG of group 2 subjects (8.7 +/- 0.3 mEq/l) was significantly lower than that of the other two groups (p less than 0.001 for both) despite their higher serum albumin and lower serum Ca in comparison to group 1. The AGs of group 1 (11.1 +/- 0.4 mEq/l) and group 3 (11.1 +/- 0.3 mEq/l) were identical. There was no statistically significant correlation between the AG and serum Ca in the hypercalcemic patients. The major finding that the association of hypercalcemia with reduced AG is seen in hyperparathyroidism, but not in malignancy-related hypercalcemia, is not explained by differences in serum albumin, renal function, or acid-base status. Overlap of values between groups limits the diagnostic usefulness of the AG in an individual patient. Nevertheless, in the absence of multiple myeloma, the finding of an AG of 5 mEq/l or less in a hypercalcemic patient may be a helpful clue suggesting that malignancy is not the etiology.

Acid-Base Equilibrium↗
PubMed1990

Age-related cognitive recovery after general anesthesia.

This study was designed to quantify the rate of mental recovery in elderly and young patients after general anesthesia for intraabdominal surgery (cholecystectomy). Forty patients (25-83 yr) were given four tests assessing neuropsychological function once preoperatively and on five occasions postoperatively. Two of the four neuropsychological tests showed impairment in scores in the elderly patients on the first postoperative day (Symbol Digit Modalities Test, P less than 0.004; The Trail Making Test, P less than 0.03). In addition, one of the tests (Symbol Digit Modalities Test) showed a deterioration in the younger patients (P less than 0.05). The changes that did occur in these tests on the first postoperative day reverted to baseline levels thereafter. There were no significant changes in the remaining two tests, the Mini Mental State Test or the Digit Span Test, at any time in either group. We conclude that postoperative mental deterioration is no greater in elderly than in young patients.

Adult↗
PubMed1990

Insulin-like growth factor 1 and its binding protein 1 during normal and diabetic pregnancies.

Investigations of circulating insulin-like growth factor 1, hPL, and infant size during pregnancy in normal and insulin-dependent diabetic women have yielded conflicting results and have not been analyzed longitudinally. We studied serial changes in maternal serum insulin-like growth factor 1 levels (measured by radioimmunoassay after acid ethanol extraction) throughout pregnancy in 22 normal women and in 38 with insulin-dependent diabetes. The diabetic women had significantly lower serum insulin-like growth factor 1 concentrations than normal women throughout pregnancy and after delivery, although the rates of change in both groups of women were similar. Within-patient analysis showed a significant decrease in serum insulin-like growth factor 1 between 6-12 weeks' gestation and a significant increase between 24-32 weeks, followed by a significant decrease from 36 weeks' gestation to 12 weeks after delivery. Incremental changes in insulin-like growth factor 1 between 24-32 weeks' gestation correlated significantly with incremental changes in hPL (r = 0.40; P less than .001) and with birth weight (r = 0.37; P less than .01), but not with ultrasound measurements of fetal growth. The correlation of increments in insulin-like growth factor 1 and birth weight became nonsignificant when the association of hPL with both insulin-like growth factor 1 and birth weight was taken into account. Neither insulin-like growth factor binding protein 1 (placental protein 12) nor its ratio to insulin-like growth factor 1 showed any association with infant size. The physiologic changes in maternal serum insulin-like growth factor 1 in pregnant diabetic women do not appear related to the increased birth weight of their infants.

Adult↗
PubMed1990

Longitudinal study of proteins in plasma and dialysate during continuous ambulatory peritoneal dialysis (CAPD).

The aim was to evaluate plasma proteins during continuous ambulatory peritoneal dialysis (CAPD) in relation to dialysis losses, membrane permeability, renal insufficiency, and time on CAPD. Ten male patients, established on CAPD for at least 14 months, were studied every 8 weeks for 56 weeks. Blood and dialysate from the morning exchange were analysed for urea, creatinine, and 7 proteins, and used to calculate dialysate to plasma concentration ratios (D/P). These ratios were not significantly changed suggesting that permeability remained constant. However, there was a trend for beta 2-microglobulin, creatinine, and urea to increase progressively. After 56 weeks, beta 2-microglobulin had increased from 27.9 to 31.3 mg/L (p less than 0.05) and creatinine 1006 to 1099 mumoL/L (p less than 0.05) and both correlated with time on CAPD (p less than 0.001). Plasma alpha 1-acid glycoprotein, albumin, transferrin, IgG, IgA, and complement C3 were not significantly changed, although IgA and complement C3 were each negatively correlated with time on CAPD (r = -0.70 and -0.67, respectively), creatinine (r = 0.51 and -0.54), and urea (r = -0.61 and -0.61) (p less than 0.001 for all). It is concluded that increases in beta 2-microglobulin, creatinine, and urea are not due to loss of membrane permeability but reflect a slight increase in uraemia. Long-term decreases in immunological proteins may be caused by uraemia or progressive depletion.

Adult↗
PubMed1990

Long-term treatment of acromegaly with a long-acting analogue of somatostatin, octreotide.

We have treated 16 acromegalic patients for up to 44 months with octreotide in varying doses. Growth hormone levels were suppressed in 14 patients with associated clinical improvement. IGF-1 levels were measured in 12 and fell into the normal range in 10. Prolactin was suppressed in six hyperprolactinaemic patients but was unaltered in normoprolactinaemic acromegalic patients. Post-prandial hyperglycaemia with impaired insulin secretion was noted in all patients, and one patient required oral hypoglycaemic agents. Octreotide did not affect thyroid function. CT scans from before and after six months of treatment demonstrated minimal tumour shrinkage in only two patients. Octreotide was well tolerated with no serious haematological or biochemical disturbance and no evidence of malabsorption. Two patients developed gallstones. Octreotide is effective in acromegaly. The development of gallstones is the only serious adverse event we have encountered.

Acromegaly↗
PubMed1990

Normal versus sickle red blood cells: hemodynamic and permeability characteristics in reperfusion lung injury.

Decreased deformability and increased internal viscosity of the sickle red blood cell (SRBC) contribute to abnormal flow in the microcirculation. Since the lungs are commonly affected in sickle cell disease, we compared the hemodynamics of the normal human red blood cell (NRBC) with the SRBC in the pulmonary circulation. The SRBC has decreased antioxidant enzyme activities compared with the NRBC. Thus, using the capillary filtration coefficient (Kfc), we determined the ability of the NRBC and the SRBC to attenuate the increased permeability and resulting edema seen in the oxidant stress of reperfusion lung injury (RLI). We found that lungs perfused with a 5% SRBC perfusate had higher pulmonary arterial pressures (Ppa) and resistances than lungs perfused with a 5% NRBC perfusate. Lungs made ischemic and reperfused with a physiologic cell-free perfusate resulted in a significant increase (P less than .05) in Kfc compared with the preischemic Kfc (.45 +/- .06 to 1.4 +/- 22 mL.min-1.cm H2O.100 g-1). In lungs reperfused with 5% RBC-containing perfusates, the Kfc did not change from preischemic Kfc with NRBCs and decreased from the preischemic Kfc with SRBCs. These findings suggest that the SRBC causes physiologically significant increases in Ppa and resistances and the SRBC, like the NRBC, offers apparent protection in RLI.

Anemia, Sickle Cell↗
PubMed1990

Bone scans after total knee arthroplasty in asymptomatic patients. Cemented versus cementless.

The natural history of bone scans after total knee arthroplasty (TKA) was studied in 26 patients with 28 cemented TKAs and 29 patients with 31 cementless TKAs. The bone scans were examined at specified postoperative intervals. Radionuclide activity of the femoral, tibial, and patellar regions was measured. Six patients who developed pain postoperatively were excluded. Bone scans immediately postoperative and at three months demonstrated increased uptake, which gradually decreased to baseline levels at ten to 12 months. Radioisotope uptake was comparable in the cemented and cementless groups, but was highly variable in individual patients and in each of the follow-up periods. A single postoperative bone scan cannot differentiate component loosening from early bone remodeling. Sequential bone scans, as a supplement to the clinical examination and conventional radiography, may prove useful in the diagnosis of TKA failure.

Aged↗
PubMed1989

A protein with several possible membrane-spanning domains encoded by the Drosophila segment polarity gene patched.

The patterning of cells in insect segments requires the exchange of information between cells, which in Drosophila depends on the activity of members of the segment-polarity class of genes. Here we report the molecular characterization of one such gene, patched. We find that patched encodes a large protein with several possible membrane-spanning domains and is expressed in a complex pattern during embryogenesis.

Alleles↗
PubMed1989

Morphology of jaw-muscle spindle afferents in the rat.

The morphology of jaw-muscle spindle afferents in the rat has been studied by intra-axonal injection of horseradish peroxidase. All stained axons were located in the motor root of the trigeminal nerve and could be traced dorsomedially to the vicinity of the trigeminal motor nucleus, where they divided into an ascending branch in the tract of the mesencephalic nucleus and a descending branch in the tract of Probst. Axon collaterals and swellings on fine collateral branches presumed to be synaptic boutons were located in the following regions: the trigeminal motor nucleus, the region dorsal to the trigeminal motor nucleus including the supratrigeminal nucleus, the parvicellular reticular formation immediately caudal to the trigeminal motor nucleus, the reticular formation at the level of the facial nucleus, and the caudal portion of the mesencephalic nucleus. No evidence of a projection to the cerebellum was observed. Boutons were most numerous in the region surrounding the trigeminal motor nucleus, especially dorsally. Here they were not demonstrated in close proximity to counterstained cells, and therefore it was not possible to determine how many of these contacts are located on cells in this region and how many are on the distal dendrites of trigeminal motorneurons. Boutons located within the trigeminal motor nucleus were always confined to a small portion of the nucleus and were significantly larger than those located dorsally. Some boutons were found in close apposition to trigeminal motorneurons and presumably make somatic contacts. These results suggest that jaw-muscle spindle afferents make somatic and proximal dendritic contacts with only a limited number of trigeminal motorneurons and also project to masticatory interneuronal regions dorsal and caudal to the motor nucleus.

Afferent Pathways↗