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Biomedical subjects

C M Cox

Publications and source records attributed to C M Cox.

17 recordsLinked to original sources
PubMed2001

The role of FGF and VEGF in angioblast induction and migration during vascular development.

The embryonic vasculature forms by the processes of vasculogenesis and angiogenesis. Angioblasts (endothelial cell precursors) appear to be induced by fibroblast growth factor 2 (FGF-2). The angioblasts contributing to the dorsal aortae arise by an epithelial to mesenchymal transformation of cells originating from the splanchnic mesoderm. QH-l and vascular endothelial growth factor receptor 2 (VEGFR-2) both appear to label these cells as they adopt a mesenchymal morphology. Since VEGFR-2 is the earliest known VEGF receptor this suggests that VEGF is not involved in angioblast induction. VEGF does appear to be critical, however, for growth and morphogenesis of angioblasts into the initial vascular pattern. Controlled delivery of FGF-2 from beads and aggregates of cells transfected with quail VEGF have been used in our laboratory to study the role of these growth factors in angioblast induction and migration. We have induced cells from the epithelial quail somite to differentiate into angioblasts with FGF-2 both in the embryo and in culture. This is a useful model system to study the origins of endothelial cells that are normally more diffusely induced during gastrulation by an obscure process probably involving signals from the embryonic endoderm. The origins of arterial versus venous endothelial cells is also poorly understood but recent findings on the distribution of ephrins and Eph receptors suggest that molecular differences exist prior to the onset of circulation. Finally, studies on the role of growth factors in such diverse phenomena as stem cell biology, angiogenesis, and molecular medicine in addition to vascular development suggest multiple roles for FGF-2 and VEGF in vascular development.

Animals↗
PubMed2001

Is it possible to decrease antibiotic prescribing in primary care? An analysis of outcomes in the management of patients with sore throats.

OBJECTIVES: The aim of this study was to assess whether it was possible to change clinical practice through the introduction of an evidence-based protocol for the management of sore throats. The impact of the changed clinical practice on patients was also assessed. METHOD: An observational study was carried out comparing management of patients with sore throats in a semi-rural general practice (14 000 patients), before and after the introduction of an evidence-based protocol, using a multidisciplinary approach. All patients over the age of 2 years presenting with sore throats as their chief presenting complaint were included in the study which ran for two 6-month periods: February-July 1997 (n = 435) and February-July 1998 (n = 350). Antibiotic prescribing rates, consultation and reconsultation rates, duration of sore throat, analgesia requirements and satisfaction were assessed. RESULTS: Antibiotic prescribing was significantly reduced in period 2 (56% compared with 19%). Consultation rates decreased by 19% in period 2. Median number of days to recovery of sore throats was the same in both groups. Reconsultation rates and dissatisfaction rates were the same in both groups. CONCLUSION: Using a multidisciplinary approach, it is possible to reduce antibiotic prescribing for sore throats significantly without adversely affecting outcome.

Anti-Bacterial Agents↗
PubMed2000

Angioblast differentiation is influenced by the local environment: FGF-2 induces angioblasts and patterns vessel formation in the quail embryo.

The embryonic vasculature forms by the segregation, migration, and assembly of angioblasts from mesoderm, a process termed vasculogenesis. The initial role of fibroblast growth factor 2 (FGF-2) in vascular development appears to be in the induction of endothelial precursors, angioblasts. Quail somites transplanted into chick embryos will give rise to angioblasts of quail origin. The number of angioblasts present within the chimera is dependent on the host environment. Angioblast induction can be demonstrated in vitro by the addition of FGF-2 to cultures of dissociated somitic mesoderm, as assessed by QH-1 epitope expression. Manipulation of FGF-2 concentration in the quail/chick chimeras by FGF-2 peptide or neutralizing antibody injections increases or decreases angioblast induction in the predicted manner. To better control growth factor release in vivo we have implanted beads that release FGF-2 into the embryonic environment. FGF-2 beads implanted into the somite induce angioblast differentiation in the epithelial somite; whereas, beads lateral to the somitic mesoderm induce the formation of ectopic vessels. These studies suggest that FGF-2 is important for both the induction of angioblasts and the assembly of angioblasts into the initial vasculature pattern.

Animals↗
PubMed2000

Effect of cardiopulmonary bypass on pulmonary gas exchange: a prospective randomized study.

BACKGROUND: Conventional coronary artery bypass surgery is associated with postoperative pulmonary dysfunction. Inflammation due to cardiopulmonary bypass has been regarded as one of the main causes. In this study, we investigated the effect of coronary revascularization with or without cardiopulmonary bypass on pulmonary function. METHODS: Fifty-two patients (40 male, mean age 60.1 years) were prospectively randomized to undergo coronary revascularization via median sternotomy, with or without normothermic cardiopulmonary bypass. Alveolar-arterial oxygen gradients were measured before and after induction of anesthesia, postoperatively in the intensive care unit during mechanical ventilation and 6 hours after tracheal extubation. The techniques of anesthesia and mechanical ventilation were standardized throughout. RESULTS: Patient characteristics were similar in the two groups. The alveolar-arterial oxygen gradients increased progressively throughout the perioperative period, with no significant differences in the two groups at any time during the study. CONCLUSIONS: Myocardial revascularization with or without cardiopulmonary bypass caused a similar degree of pulmonary dysfunction, as assessed by alveolar-arterial oxygen gradient. Our study suggests that the deterioration in pulmonary gas exchange associated with cardiac surgery is due to factors other than the use of cardiopulmonary bypass.

Body Temperature↗
PubMed2000

High-carbohydrate versus high-fat diets: effect on body composition in trained cyclists.

PURPOSE: Recent research suggesting the benefits of high-fat diets for endurance athletes have been viewed with caution because of the potential negative health consequences, including increased adiposity. METHODS: We have examined the effects of a high-fat (HF, 50% of total energy from fat and 37% from carbohydrate) versus a high-carbohydrate (HC, 15% of total energy from fat and 69% from carbohydrate) diet on body fat, lean body mass, and bone mineral density (BMD) in 32 endurance-trained cyclists over a period of 3 months. Body composition was assessed by dual x-ray absorptiometry at baseline and after 3 months. RESULTS: Total and percent body fat, lean tissue mass, and body weight were not significantly different within and between each diet group from baseline to week 12. Total body BMD increased significantly within HF (P = 0.02), but nonsignificantly in HC, over the 12-wk period. CONCLUSIONS: In conclusion, during periods of endurance training when energy requirements are high, increasing the percentage of fat in the diet to approximately 50% of total energy does not increase body weight or adiposity because athletes are able to maintain energy balance.

Adolescent↗
PubMed2000

Different ontogeny of rate of force generation and shortening velocity in guinea pig trachealis.

Juveniles of many species, including humans, display greater airway responsiveness than do adults. This may involve changes in airway smooth muscle function. In the present work we studied force production and shortening velocity in trachealis from 1-wk-old (1 wk), 3-wk-old (3 wk), and 3-mo-old (adult) guinea pigs. Strips were electrically stimulated (60 Hz, 18 V) at their optimal length (l(o)) to obtain maximum active stress (P(o)) and rate of stress generation. Then, force-velocity curves were elicited at 2.5 s from the onset of the stimulus. By applying a recently developed modification of Hill's equation for airway smooth muscle, the maximum shortening velocity at zero load (V(o)) and the value alpha. gamma/beta, an index of internal resistance to shortening (Rsi), were calculated (alpha, beta, and gamma are the constants of the equation). P(o) increased little with maturation, whereas the rate of stress generation increased significantly (0.40 +/- 0.03, 0.45 +/- 0.03, 0. 51 +/- 0.03 P(o)/s for 1 wk, 3 wk, and adult animals). V(o) slightly increased early with maturation to decrease significantly later (1. 79 +/- 0.67, 2.45 +/- 0.92, and 0.55 +/- 0.09 l(o)/s for 1 wk, 3 wk, and adult animals), whereas the Rsi showed an opposite trend (14.98 +/- 5.19, 8.99 +/- 3.01, and 32.07 +/- 5.54 mN. mm(-2). l(o)(-1). s for 1 wk, 3 wk, and adult animals). This early increase of force generation in combination with late increase of Rsi may explain the changes of V(o) with age. An elevated V(o) may contribute to the incidence of airway hyperresponsiveness in healthy juveniles.

Aging↗
PubMed1998

Effects of high fat versus high carbohydrate diets on plasma lipids and lipoproteins in endurance athletes.

PURPOSE AND METHODS: Recent research suggesting the performance benefits of high fat diets for endurance athletes have been viewed with caution because of the potential negative health consequences, including increased coronary heart disease risk. This study examined the effects of a high fat (HF: 50% of total energy from fat, 37% carbohydrate) versus a high carbohydrate (HC: 15% of total energy from fat, 69% carbohydrate) diet on plasma lipids and lipoproteins in 32 endurance trained cyclists over a 3-month period. Plasma total, low density lipoprotein (LDL), high density lipoprotein (HDL), HDL2 and HDL3 cholesterol, triglycerides, apolipoprotein A1, and hematocrit (Hct) were measured at baseline and after weeks 4, 8, and 12. RESULTS: Changes in lipids and lipoproteins from baseline to week 12 did not differ between the two groups except for triglycerides, which increased significantly from 1.04 +/- 0.17 mmol.L-1 to 1.28 +/- 0.31 mmol.L-1 in HC (P = 0.012). The only significant changes that occurred within each group from baseline to week 12 was the significant increase in total cholesterol and triglycerides in HC. Body composition changes did not differ between the two groups from baseline to week 12 as measured by dual x-ray absorptiometry. CONCLUSIONS: During periods of endurance training when energy requirements are high, increasing the percentage of fat in the diet to approximately 50% of total energy did not result in adverse changes to the plasma lipoprotein profiles of this group of athletes.

Absorptiometry, Photon↗
PubMed1996

Topical lignocaine and thiopentone for the insertion of a laryngeal mask airway; a comparison with propofol.

We assessed conditions for insertion of a laryngeal mask airway in 90 unpremedicated adult patients who received either thiopentone 5 mg.kg-1 preceded by 40 mg of topical lignocaine spray to the posterior pharyngeal wall or propofol 2.5 mg.kg-1 alone in a randomised, single-blinded trial. All patients received fentanyl 1 microgram.kg-1. Gagging, coughing and laryngospasm following laryngeal mask insertion were graded and haemodynamic data and apnoea times were recorded. There were no significant differences between the two groups with regard to the incidence of gagging, coughing and laryngospasm, but the apnoea time was significantly less in the thiopentone group (p < 0.005). The decrease in systolic and diastolic blood pressure, following induction and the insertion of a laryngeal mask with propofol was significantly greater than following thiopentone (p < 0.05--systolic, p < 0.01--diastolic). We conclude that thiopentone preceded by topical lignocaine spray provides conditions for insertion of a laryngeal mask equal to those of propofol, with more haemodynamic stability and a shorter period of apnoea.

Adolescent↗
PubMed1996

Lignocaine to aid the insertion of the laryngeal mask airway with thiopentone. A comparison between topical and intravenous administration.

Conditions for insertion of a laryngeal mask airway in 90 unpremedicated adult were patients were assessed in a randomised, single-blinded trial. Each patient received fentanyl 1 microgram.kg-1 and thiopentone 5 mg.kg-1, and this was preceded either by lignocaine 0.5 mg.kg-1 intravenously (group 1), lignocaine 1.5 mg.kg-1 intravenously (group 2) or 40 mg of topical lignocaine spray to the posterior pharyngeal wall (group 3). Conditions for laryngeal mask airway insertion were recorded. The group receiving topical lignocaine had a lower incidence of laryngospasm (p < 0.05), required fewer attempts for successful insertion of the laryngeal mask (p < 0.05) and coughed or gagged less frequently than either group receiving lignocaine intravenously (p > 0.05). Overall, the conditions for laryngeal mask airway insertion were better in the topical group (p < 0.05). There were no significant differences in haemodynamic response and apnoea between the three groups. Topical lignocaine spray prior to thiopentone provides conditions for insertion of a laryngeal mask that are superior to those provided by lignocaine and thiopentone intravenously.

Administration, Topical↗
PubMed1996

Response of plasma lathosterol concentration to change in the quality of dietary fat in men and women.

OBJECTIVE: The aim of the study was to determine the effect of replacing saturated fatty acids (SAFA) with polyunsaturated fatty acids (PUFA) in the diet on plasma lathosterol concentration, an index of cholesterol synthesis, in mildly hypercholesterolaemic subjects. DESIGN: The study was a randomised, cross-over trial. SUBJECTS: Seventy-six subjects were recruited and one dropped out. Twenty-nine men and 46 women with baseline plasma cholesterol levels in the range 5.5-7.9 mmol/l were entered into the trial. INTERVENTIONS: Subjects were placed on two isocaloric diets, one rich in SAFA and the other high in PUFA, for 6 weeks each. Plasma lathosterol and lipid and lipoprotein concentrations were measured. RESULTS: When PUFA replaced SAFA in the diet, there was a significant (P = 0.01) fall in plasma lathosterol concentration in all subjects combined [-1.37 (-0.36 to -2.38) mumol/l] which was largely due to a significant (P = 0.03) decrease in men [-2.35 (-0.42 to -4.28) mumol/l] but not in women. The concomitant decreases in plasma cholesterol, low density lipoprotein (LDL) cholesterol and high density lipoprotein (HDL) cholesterol were similar in men and women. Plasma lathosterol concentration and the ratio lathosterol/cholesterol were significantly higher in men at baseline and during diets rich in SAFA but were not significantly different between the sexes during diets rich in PUFA. CONCLUSIONS: These data suggest that replacing SAFA with PUFA in the diet may reduce cholesterol synthesis in mildly hypercholesterolaemic men and markedly reduce the gender-related difference in cholesterol synthesis commonly observed.

Adult↗
PubMed1994

Cholesteryl ester transfer in patients with renal failure or renal transplants.

Plasma newly-synthesized cholesteryl ester transfer (NCET) rate and concentrations of lipids, lipoproteins and apolipoproteins A1 and B were measured in chronic renal failure patients (dialysis independent and dialysis dependent), patients with a functioning renal transplant and in healthy control subjects with comparable ages and plasma triglycerides. Plasma NCET rates and apoB concentrations were significantly higher in patients treated by continuous ambulatory peritoneal dialysis (CAPD) compared with controls. In normolipidemic subjects (cholesterol < 6.5 mmol/liter, triglycerides < 2.0 mmol/liter), plasma NCET rates did not differ significantly from rates in the corresponding control subjects. In hyperlipidemic subjects, plasma NCET rates were significantly higher than rates in the normolipidemic subgroup. Plasma NCET rates were correlated closely with plasma apoB levels in all renal patients combined (r = 0.754, N = 53, P < 0.001) and with plasma cholesteryl ester mass transfer (r = 0.853, N = 13, P < 0.001). We conclude that, in the absence of hyperlipidemia, plasma NCET rate is normal in patients with chronic renal failure irrespective of the treatment for uremia, and when hyperlipidemia is present NCET rates are raised and may contribute to elevated levels of the proatherogenic apoB-containing lipoproteins.

Adolescent↗
PubMed1991

Turnover of cell surface-bound capsular polysaccharide in Staphylococcus aureus.

The capsular polysaccharide (CPS) of Staphylococcus aureus strain Smith was labelled by growth of bacteria in the presence of radioactive N-acetylglucosamine and was separated from labelled cell wall components by affinity chromatography on wheat germ agglutinin following dissolution of the cells by lysostaphin. The products were partially characterised chemically and immunochemically. Similar labelled components were found in the culture fluid during growth. In a pulse-chase experiment, cell-bound CPS was released continuously into the culture fluid at the same rate as cell wall turnover and there was no evidence of direct excretion of CPS.

Acetylglucosamine↗
PubMedDate not supplied

Model hospital outreach service.

The Outreach Dental Care Service of Swedish American Hospital, Rockford, IL, brings a hygienist to local long-term care facilities, who provides prophylaxis, cleans partial dentures and complete dentures, plans individualized daily oral hygiene regimens, trains facility caregivers, and educates staff members.

Dental Care for Persons with Disabilities↗