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Biomedical subjects

S Wilson

Publications and source records attributed to S Wilson.

At least 451 records · Page 25Linked to original sources
PubMed1988

The asparagine-linked oligosaccharides on bovine fetuin. Structural analysis of N-glycanase-released oligosaccharides by 500-megahertz 1H NMR spectroscopy.

The structures of the entire population of sialylated asparagine-linked oligosaccharides present on bovine fetuin were elucidated. Asparagine-linked oligosaccharides were released from fetuin with N-glycanase, radiolabeled by reduction with NaB[3H]4, and fractionated by anion-exchange high performance liquid chromatography (HPLC), ion-suppression amine adsorption HPLC, and concanavalin A affinity chromatography. The 3H-labeled oligosaccharide fractions obtained were analyzed by 500-MHz 1H nuclear magnetic resonance spectroscopy, revealing the presence of 23 distinct oligosaccharide structures. These oligosaccharides differed in extent of sialylation (3% mono-, 35% di-, 54% tri-, and 8% tetrasialylated), number of peripheral branches (17% di- and 83% tribranched), linkage (alpha 2,3 versus alpha 2,6) and location of sialic acid moieties, and linkage (beta 1,4 versus beta 1,3) of galactose residues. This represents the first time that the asparagine-linked oligosaccharides of fetuin have been successfully fractionated and characterized as sialylated species. The sialylated oligosaccharides derived from fetuin were also used to further define the specificities of the lectins leukoagglutinating phytohemagglutinin and Ricinus communis agglutinin I. The behavior of these oligosaccharides during lectin affinity HPLC further establishes the structural features which predominate in the interaction of oligosaccharides with leukoagglutinating phytohemagglutinin and R. communis agglutinin I.

Asparagine↗
PubMed1988

Nonfunctioning islet cell carcinoma of the pancreas. Complete response to continuous 5-fluorouracil infusion.

An unresectable, intraabdominal recurrence of a nonfunctioning islet cell carcinoma of the pancreas developed in a 56-year-old man 9 years after he achieved complete remission from extensive radiotherapy. Chronic renal failure secondary to radiation nephritis precluded the use of streptozotocin. 5-fluorouracil (5-FU) (300 mg/m2 per day) was given as a continuous, systemic infusion through a chronic indwelling central venous catheter for 1 year's duration. Treatment resulted in the prompt disappearance of all signs and symptoms of cancer, and computed tomography (CT) of the abdomen documented complete response. The patient continues in complete clinical remission 16 months after 5-FU was stopped. Continuous 5-FU infusion may be a potentially efficacious and less toxic alternative to streptozotocin in the treatment of islet cell carcinoma. Further clinical evaluation will be necessary to define its overall role in the management of these patients.

Adenoma, Islet Cell↗
PubMed1988

Clonal heterogeneity, experimental metastatic ability, and p21 expression in H-ras-transformed NIH 3T3 cells.

We examined individual clones of murine NIH 3T3 cells, transformed with the human bladder cancer (T24) H-ras oncogene, for p21 expression and for experimental metastatic ability in the immunodeficient chick embryo. We found that the clones were heterogeneous for both of these properties. In general, p21 expression was a good predictor of metastatic ability of the clones. Cells from poorly metastatic clones were passaged in the chick embryo metastasis assay to determine whether cells with increased metastatic ability could be selected. We found that the selected cells were more metastatic and that substantial increases in expression of p21 also accompanied this increase in metastatic ability. The relationship between p21 expression and metastatic ability appeared linear, with a high correlation coefficient (r = .85), suggesting that in this model system quantitative increases in metastatic properties can result from increased expression of the ras oncogene protein product p21.

Animals↗
PubMed1988

An investigation of the beta-adrenoceptor that mediates metabolic responses to the novel agonist BRL28410 in rat soleus muscle.

The beta-adrenoceptor agonist BRL26830A selectively stimulates metabolic rate in the rat and this thermic effect is resistant to blockade by propranolol. These effects of BRL26830A are partly due to selective stimulation by its metabolite BRL28410, of brown adipocyte beta-adrenoceptors, these receptors being resistant to propranolol. To investigate whether the metabolic effects of BRL28410 in skeletal muscle are also mediated by atypical beta-adrenoceptors, the potencies of BRL28410 and isoprenaline were compared for beta-adrenoceptor mediated responses in rat stripped soleus muscle. In addition, pA2 values for antagonism by propranolol of these responses were determined. Isoprenaline had similar EC50 values for stimulation of lactate formation (4.3 X 10(-9) M) and inhibition of glycogen synthesis (3.4 X 10(-9) M) and these values are similar to its reported EC50 values for stimulation of atrial rate (beta 1-adrenoceptor-mediated) and relaxation of the uterus (beta 2-adrenoceptor-mediated). BRL28410 had similar EC50 values for stimulation of lactate formation (3.7 X 10(-6) M) and inhibition of glycogen synthesis (3.8 X 10(-6) M). These values are only about two-fold less than reported values for relaxation of the uterus, but ten-fold less than reported values for stimulation of atrial rate. The pA2 value of dl-propranolol for antagonism of the effect of isoprenaline on glycogen synthesis (8.38 +/- 0.13) was in the range expected for beta 1- or beta 2-adrenoceptors, but with BRL28410 as agonist the pA2 value was about one unit lower (7.39 +/- 0.11). The beta-adrenoceptors that mediate the metabolic effects of BRL28410 in soleus muscle therefore differ from those that mediate atrial rat, uterine relaxation and adipocyte lipolysis. In addition, the low pA2 value of dl-propranolol versus BRL28410 in rat soleus muscle, which contrasts with the normal pA2 value previously reported for guinea-pig trachea, suggests that beta 2-adrenoceptors in these two tissues can be differentiated with suitable pharmacological agents.

Animals↗
PubMed1988

Young age as a prognostic factor in cervical cancer: analysis of population based data from 10,022 cases.

The effect of young age on survival in cervical cancer is not fully known, although evidence has suggested that it is a poor prognostic factor and that young patients should therefore be treated differently from older patients. All 10,022 cases of invasive cervical cancer in the west Midlands during 1957-81, which comprised 10% of the cases in England and Wales, were analysed to determine the prognostic effect of age. Univariate analysis showed a median survival time of 54 months for all cases, with survival rates at five years of 69% for patients aged under 40 and 45% for those aged 40 or older (chi 1(2) (log rank) = 331.4; p less than 0.0001). This difference remained significant after stratification for stage (chi 1(2) (log rank) = 7.1; p = 0.008). Cox regression analysis with nine covariables, including age and year of registration, reaffirmed the importance of conventional prognostic factors such as stage of disease, size of tumour, state of lymph nodes, and differentiation of the tumour. After allowance was made for the effects of other prognostic factors young age was found to be a small but significant favourable factor that did not change during the period of the study. Estimated survival distributions obtained from the Cox model showed that for women presenting with the common characteristics associated with stage Ib disease who were treated with radical radiotherapy the survival rate at five years fell non-linearly from 71% in the group aged 25-29 to 65% in the group aged 65-69. Young age alone is not a reason to alter existing policies for treatment for patients with invasive cervical cancer.

Adenocarcinoma↗
PubMed1988

Acute effects of a beta-adrenoceptor agonist (BRL 26830A) on rat brown-adipose-tissue mitochondria. Increased GDP binding and GDP-sensitive proton conductance without changes in the concentration of uncoupling protein.

GDP binding, proton conductance and the specific concentration of uncoupling protein were measured in brown-adipose-tissue mitochondria of rats treated acutely with the novel beta-agonist, BRL 26830A. At 1 h after dosing with BRL 26830A, mitochondrial GDP binding was increased more than 2-fold. The increase in binding resulted from an increase in the number of binding sites. An iterative analysis of Scatchard binding data suggested that there is only one high-affinity GDP-binding site (Kd 0.3 microM) in brown-adipose-tissue mitochondria. The acute increase in GDP binding produced by treatment with BRL 26830A occurred without any alteration in the specific mitochondrial concentration of uncoupling protein, as determined by radioimmunoassay. Treatment with the beta-agonist did, however, lead to a small increase in the GDP-sensitive component of mitochondrial proton conductance. These results indicate that GDP-binding sites on uncoupling protein can be rapidly unmasked after treatment with a brown-fat-specific beta-agonist, and that the increase in binding reflects an increase in the activity of the mitochondrial proton-conductance pathway.

Adipose Tissue, Brown↗
PubMed1988

Transabdominal chorionic villus sampling in the second trimester.

Transabdominal chorionic villus sampling under ultrasound guidance was carried out in 19 patients in the second trimester. We found that needle size combination 17/19 provided the best results with consistently adequate samples of tissue. Transabdominal chorionic villus sampling is a potentially useful technique for providing relatively rapid prenatal genetic diagnosis in patients at high risk in the second trimester.

Biopsy↗
PubMed1988

Melanotic neuroectodermal tumor of infancy: evidence for multicentricity.

The melanotic neuroectodermal tumor of infancy (MNTI) is a rare neoplasm that is believed to be derived from cells of the neural crest. This case demonstrates a multicentric distribution of the MNTI. The possibility of a multicentric variant of benign MNTI is discussed with respect to both the present case and previously described reports. Suggestions for evaluation and surgical management are given.

Alveolar Process↗
PubMed1988

Effects of sulphur dioxide, hydrogen fluoride and their combination on three Eucalyptus species.

The effects of joint action of SO(2) and HF on three Eucalyptus species were studied by exposing them to combinations of < 13, 122 or 271 microg m(-3) of SO(2) and 0.03, 0.39 or 1.05 microg m(-3) of HF in open top chambers for 120 days. HF and SO(2) reduced the area and weight of immature leaves in all three species, but there were few interactive effects on immature leaves. The response of mature leaves to exposure differed among the species, with the greatest effects on E. calophylla and least effects on E. marginata. The interaction of HF + SO2 had no effect on leaf S concentrations in any of the species, but it reduced leaf F concentrations in E. calophylla and E. gomphocephala. HF increased leaf injury in E. calophylla and E. gomphocephala when simultaneously exposed to 271 microg m(-3) of SO(2), but had no effect at 122 microg m(-3), or on E. marginata. The addition of 271 microg m(-3) of SO(2) increased leaf injury when E. gomphocephala was exposed to 0.39 microg m(-3) of HF and when E. calophylla was exposed to 1.05 microg m(-3) of HF, despite reducing the leaf F concentrations. In some cases the interaction of the pollutants may increase susceptibility to visible injury.

Journal Article↗
PubMed1988

The joint action of sulphur dioxide and hydrogen fluoride on the yield and quality of wheat and barley.

The effects of joint action of SO(2) and HF on the yield and quality of wheat and barley were studied by exposing them to combinations of <13,130 or 267 microg m(-3) SO(2) and 0.03 or 0.38 microg m(-3) HF in open top chambers for 90 days. At the concentrations used, SO(2) had greater effects than HF. All responses were marked by compensatory changes. The treatments had no effect on wheat yield, although SO(2) reduced shoot weight. SO(2) increased the growth and yield of barley, and HF or SO(2) increased the grain protein concentration of barley and wheat. The effects of mixtures of SO(2) and HF were complex, but often antagonistic, as the addition of HF counteracted the effect of SO(2) alone.

Journal Article↗
PubMed1988

Confidants and family structure in old age.

Previous research has shown that confiding has a major influence on well-being in old age, but little is known about the availability and selection of confidants. Drawing from a survey of the social networks of 1,050 persons aged 60 and older in Sydney, Australia, this study explored aspects of the influence of age, gender, and family structure in predicting the choice of confidants among potentially available spouses, children, siblings, and other persons in informal relationships. Logistic regression was used because the response variable was dichotomous and because several explanatory variables, which were both categorical and continuous, were being examined simultaneously. The findings indicated that people tended to confide in more distant family or nonfamily when close family members were not available. The relative importance of variables differed substantially between types of confiding relationships and between gender and age groups of respondents. Our findings suggest the need for longitudinal research and more sensitive methods of analysis in exploring the complexities of maintaining and re-forming primary bonds through the course of old age.

Age Factors↗