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Biomedical subjects

S G Anderson

Publications and source records attributed to S G Anderson.

At least 19 recordsLinked to original sources
PubMed2006

Insulin-like growth factor binding protein-2 (IGFBP-2) is a marker for the metabolic syndrome.

AIMS/HYPOTHESIS: IGFs and their binding proteins are increasingly recognised as important in understanding the pathogenesis of cardiovascular disease. Low IGFBP-1, particularly coupled with low IGF-I, is associated with increased cardiovascular risk. In relation to structural and regulatory parallels between IGFBP-1 and - 2 we have now examined the hypothesis that IGFBP-2 may be a marker for cardiovascular risk. METHODS: Fasting IGFBP-2, IGFBP-1, IGFBP-3, IGF-I, IGF-II, insulin, C-peptide, glucose, lipids, NEFAs, and HbA1c were measured in a cohort of 163 patients with type 2 diabetes. Individuals were categorised according to the presence or absence of the metabolic syndrome. RESULTS: Patients with the metabolic syndrome had a lower IGFBP-2 concentration. Low circulating IGFBP-2 was associated with elevated fasting glucose (rho = - 0.23, p = 0.003). IGFBP-2 correlated negatively with triglycerides (rho = - 0.19, p = 0.01) and LDL-cholesterol (rho = - 0.20, p = 0.01), and positively with insulin sensitivity (HOMA-S) (rho = 0.26, p = 0.02). Multivariate logistic regression demonstrated that low IGFBP-2 was independently associated with an increased risk of the metabolic syndrome (OR 0.31 [95 % CI 0.11 - 0.90]; p = 0.03). IGFBP-3 did not differ according to the presence or absence of metabolic syndrome. CONCLUSION/INTERPRETATION: Low IGFBP-2 is associated with multiple cardiovascular risk factors similarly to IGFBP-1. Such associations were not apparent for IGFBP-3. Lack of marked prandial regulation of IGFBP-2, in contradistinction to IGFBP-1, may make IGFBP-2 a more robust biomarker for identification of insulin-resistant individuals at high cardiovascular risk in epidemiological studies.

Biomarkers↗
PubMed2005

Marked differences in the IGF system that are associated with migration in comparable populations of Gujaratis living in Sandwell, UK, and Gujarat, India.

AIMS/HYPOTHESES: We previously reported independent links between the IGF system and the development of impaired glucose tolerance and cardiovascular risk. This study tests the hypothesis that the lifestyle change which accompanies population migration, with attendant increases in cardiovascular risk, is reflected by changes in the IGF system. MATERIALS AND METHODS: We compared a specific Gujarati community in Sandwell, UK (n=205), with people still resident in the same villages of origin near Navsari, India (n=246). We performed anthropometry and measured fasting plasma insulin, IGF-I, insulin-like growth factor binding protein (IGFBP)-1 and IGFBP-3. RESULTS: Daily calorie intake, BMI and WHR were significantly higher in UK Gujaratis than in Indian Gujaratis. IGFBP-1 was significantly lower in UK migrants (mean 29.5 [95% CI 25.9-33.0] vs 56.5 [50.6-62.5] microg/l; F=48.4, p<0.001). Conversely, fasting insulin, IGFBP-3 and IGF-I were all higher in UK Gujaratis (mean IGF-I 145.9 [138.1-153.6]ng/ml in UK Gujaratis and 100.9 [94.6-107.3] ng/ml in Navsari Gujaratis; F=76.6, p<0.001). These differences were still apparent when adjustment was made for BMI by location for IGF-I (F=57.4, p<0.001) and IGFBP-3 (F=5.7, p=0.02), but were no longer apparent for IGFBP-1 and insulin. At the population level, the decrease in IGFBP-1 for a given increase in insulin was significantly smaller in UK Gujaratis, suggesting greater hepatic insulin resistance in this group. CONCLUSIONS/INTERPRETATION: Environmental factors have profound effects on circulating IGF system components and on the relationship between IGFBP-1, IGF-I and related metabolic variables. This may have long-term implications for the development of worsening glucose tolerance and cardiovascular disease.

Blood Glucose↗
PubMed2005

Low sex hormone binding globulin is a potential marker for the metabolic syndrome in different ethnic groups.

Hepatic sex-hormone binding globulin (SHBG) production is down-regulated by insulin and low levels reflect insulin resistance. Because insulin resistance is closely related to the development of cardiovascular disease in different ethnic groups we examined ethnic variation in SHBG across populations with different baseline cardiovascular risk and metabolic syndrome prevalence. Participants were population-based, of European (n = 142), Pakistani (n = 130), and African-Caribbean (AfC) origin (n = 193). SHBG, fasting lipids, and glucose concentrations plus insulin sensitivity (HOMA-S) were determined. Age adjusted SHBG was significantly lower in both Pakistani men and women. Circulating SHBG levels were lower in those with impaired vs. normal glucose homeostasis. SHBG correlated positively with HOMA-S (rho = 0.28, p < 0.001), and negatively with WHR (rho = - 0.38, p < 0.001), BMI (r = - 0.30, p < 0.001), and diastolic blood pressure (rho = - 0.14, p < 0.01) across all ethnic groups. In multivariate logistic regression analysis a low SHBG increased the likelihood of the metabolic syndrome (odds ratio [OR] = 0.42 [0.21 - 0.82], p = 0.01) as did higher fasting NEFA (OR 1.47 [1.04 - 2.08], p = 0.03), low IGFBP-1 concentrations (OR 0.6 [0.44 - 0.81], p = 0.001), age (OR 1.05 [1.02 - 1.09], p = 0.003), and Pakistani ethnicity (p = 0.001) in a model which also contained gender, lnCRP, IGF-I, and IGF-II. As ethnic differences in SHBG level closely parallel differences in insulin resistance. Its measurement may be useful in identifying individuals at particular risk of the metabolic syndrome, for early intervention.

Biomarkers↗
PubMed2005

Dietary intake and the insulin-like growth factor system: effects of migration in two related populations in India and Britain with markedly different dietary intake.

BACKGROUND: The insulin-like growth factor (IGF) system is implicated in the pathogenesis of diabetes and cardiovascular disease. OBJECTIVE: We report the effects of total energy intake on the IGF system in two populations with markedly different dietary macronutrient intake and cardiovascular event rate. DESIGN, SUBJECTS AND SETTING: Dietary macronutrient intake was measured in a specific Gujarati migrant community in Sandwell, UK (n=205) compared with people still resident in the same villages of origin in India (n=246). Fasting IGF-I, IGF-binding protein (IGFBP)-1 and IGFBP-3, insulin and glucose (0 and 2-hour) were measured. RESULTS: Total energy and total fat intake were higher in UK migrants, as were IGFBP-3 and IGF-I (mean (95% confidence interval): 145.9 (138.1-153.6) vs. 100.9 (94.6-107.3) ng ml(-1); F=76.6, P<0.001). IGFBP-1 was lower in UK migrants (29.5 (25.9-33.0) vs. 56.5 (50.6-62.5) microg l(-1); F=48.4, P<0.001). At both sites, IGF-I correlated positively with total energy (Spearman's rho=0.45, P<0.001) and total fat (rho=0.44, P<0.001) as did IGFBP-3 with total energy (rho=0.21, P<0.05) and fat (rho=0.26, P<0.001). Conversely, in Indian Gujaratis, IGFBP-1 fell with increasing total energy (rho=-0.27, P<0.001) and fat intake (rho=-0.26, P<0.01) but not in UK Gujaratis. Multiple linear regression modelling showed that increasing quartiles of fat intake were associated with higher IGF-I (beta=0.42, P=0.007) independent of age, body mass index, plasma insulin, fatty acids and 2-hour glucose. CONCLUSION: In these genetically similar groups, migration to the UK and adoption of a different diet is associated with marked changes in the IGF system, suggesting that environmental factors profoundly modulate serum concentrations and actions of IGFs.

Blood Glucose↗
PubMed2003

Horizontal phase-space distortions arising from magnetic pulse compression of an intense, relativistic electron beam.

We report detailed measurements of the transverse phase space distortions induced by magnetic chicane compression of a high brightness, relativistic electron beam to subpicosecond length. A strong bifurcation in the phase space is observed when the beam is strongly compressed. This effect is analyzed using several computational models and is correlated to the folding of longitudinal phase space. The impact of these results on current research in collective beam effects in bending systems and implications for future short wavelength free-electron lasers and linear colliders are discussed.

Journal Article↗
PubMed2002

Natural history and prognostic factors of diabetic nephropathy in type 2 diabetes.

BACKGROUND: The causes and mechanisms of increased mortality of patients with diabetic nephropathy are unclear, and its natural history is poorly understood. AIM: To evaluate risk factors for mortality in type 2 diabetic patients with nephropathy. DESIGN: Retrospective study of clinical and biochemical parameters in diabetic nephropathic patients and controls sampled from a secondary care register. METHODS: We studied 170 type 2 diabetic patients (from 1987 to 1995) with nephropathy (proteinuria >0.5 g/24 h) and 170 non-nephropathic patients. Follow-up was until death or December 1997. Details of demographics, clinical and treatment history were obtained from medical records. RESULTS: Mean follow-up was 5.3 years. Of the patients with nephropathy at baseline, 63 (37%) died compared with 14 (8%) non-nephropathic patients (chi(2)=53.8, p<0.0001). Age- and sex-adjusted all-cause mortality rates were 8.1 (6.4, 9.8) and 1.4 (0.5, 2.2) deaths per 100 person-years, respectively (rate ratio 5.8). Forty-four patients (57%) died from cardiovascular causes (rate ratio 5.4). Mortality was directly proportional to degree of proteinuria: 0.5-2 g/24 h, 4.6 (2.9-7.1); >2 g/24 h, 9.9 (7.3-13.5) per 100 patient-years. A 36% (5-78%) excess risk of mortality was observed for each log unit increase in proteinuria. Multivariate Cox regression analyses confirmed a five-fold excess risk for all-cause and cardiovascular mortality in patients with nephropathy compared with those without. This was independent of other risk factors including baseline age [5% (1-8%)/year], creatinine [2.5 (1.12-5.6)/10 micromol/l] and glycaemic control (HbA(1c)) [15% (1-31%) per 1% rise]. CONCLUSIONS: Proteinuria is a potentially preventable and reversible risk factor associated with high mortality in type 2 diabetic patients. Prevention of the development of overt nephropathy and improvement in diabetes control may reduce mortality in these patients.

Aged↗
PubMed2001

Hypertension in four African-origin populations: current 'Rule of Halves', quality of blood pressure control and attributable risk of cardiovascular disease.

OBJECTIVE: To assess the public health burden from high blood pressure and the current status of its detection and management in four African-origin populations at emerging or high cardiovascular risk. DESIGN: Cross-site comparison using standardized measurement and techniques. SETTING: Rural and urban Cameroon; Jamaica; Manchester, Britain. SUBJECTS: Representative population samples in each setting. African-Caribbeans (80% of Jamaican origin) and a local European sample in Manchester. MAIN OUTCOME MEASURES: Cross-site age-adjusted prevalence; population attributable risk. RESULTS: Among 1,587 men and 2,087 women, age-adjusted rates of blood pressure > or =160 or 95 mmHg or its treatment rose from 5% in rural to 17% in urban Cameroon, despite young mean ages, to 21% in Jamaica and 29% in Caribbeans in Britain. Treatment rates reached 34% in urban Cameroon, and 69% in Jamaican- and British-Caribbean-origin women. Sub-optimal blood pressure control (> 140 and 90 mmHg) on treatment reached 88% in European women. Population attributable risks (or fractions) indicated that up to 22% of premature all-cause, and 45% of stroke mortality could be reduced by appropriate detection and treatment. Additional benefit on just strokes occurring on treatment could be up to 47% (e.g. in both urban Cameroon men and European women) from tighter blood pressure control on therapy. Cheap, effective therapy is available. CONCLUSION: With mortality risk now higher from non-communicable than communicable diseases in sub-Saharan Africa and elsewhere, systematic measurement, detection and genuine control of hypertension once treated can go hand-in-hand with other adult health programmes in primary care. Cost implications are not great. The data from this collaborative study suggest that such efforts should be well rewarded.

Adult↗
PubMed1999

Diabetes in the Caribbean: results of a population survey from Spanish Town, Jamaica.

AIMS: To characterize the prevalence of diabetes and associated risk attributes in the Jamaican population. METHODS: A random population sample was recruited by door-to-door canvassing (n = 1303). A final participation of 60% was achieved. Oral glucose tolerance testing was conducted after an overnight fast and standard anthropometric and demographic data were collected. RESULTS: The prevalence of Type 2 diabetes mellitus was 9.8% (95% confidence interval (CI) 7.2-12.4) among men and 15.7% (95% CI 13.1-18.3) among women with an overall prevalence of 13.4% (95% CI 11.5-15.2). Impaired glucose tolerance was found among 12.3% of men and 14.7% of women. The sex patterns were consistent with a fourfold excess of obesity in women compared to men. The odds ratios for diabetes, fourth vs. first quartiles were 5.42 (95% CI 2.02-16.88) in men and 3.32 (95% CI 1.73-6.63) in women for body mass index (BMI) and 17.39 (95% CI 3.86-78.27) in men and 5.48 (95% CI 2.84-11.00) in women for WHR in a logistic model controlling for age. The population attributes risk percentage, for diabetes, of being overweight and having waist-to-hip ratio (WHR) greater than the median (0.80) were 66% and 80%, respectively. The contribution of central obesity, as characterized by WHR, was also significant in sex-specific multivariate models that included age and BMI. Prevalent hypertension and family history of diabetes were likewise associated with increased odds of having the disease. CONCLUSIONS: The prevalence of diabetes in Jamaica now exceeds that observed among European-origin populations and reflects the emerging epidemic of obesity. The excess risk for this population could not be attributed entirely to relative weight. The pronounced sexual dimorphism in diabetes prevalence most likely reflects the substantial excess of obesity among women compared to men. Like many other island nations, Caribbean societies now appear to be at substantial risk of diabetes.

Aged↗
PubMed1998

The potential role of cell adhesion molecules in the pathogenesis of diabetic neuropathy.

Cross-sectional studies have shown plasma cell adhesion molecules (CAMs) to be increased in patients with diabetes-related complications. In the first prospective study of CAMs, we have shown that plasma CAMs may be a predictor of the development of diabetic neuropathy. We followed up 28 diabetic patients (13 neuropathic) over a 5 year period, starting from 1991. All patients had peroneal nerve conduction velocity (PNCV), vibration perception threshold and plasma CAMs measured at baseline and follow-up. We found P-selectin and intercellular adhesion molecule-1 (ICAM-1) to be increased at baseline in patients with neuropathy compared to non-neuropathic patients. P-selectin and E-selectin were also found to be significantly higher at baseline in patients who at follow-up showed deterioration in PNCV of more than 3 m/s (p<0.05; p=0.01; respectively). P-selectin and ICAM-1 strongly correlated with PNCV. Univariate and multivariate regression analyses showed a significant inverse association between increasing log P-selectin, log E-selectin and log ICAM-1 with decreasing PNCV, and remained significant even after adjustment for glycaemic control. P-selectin and E-selectin, odds ratios of 8.8 (95% CI: 1.1-68.8; p=0.038) and 12.5 (95% CI: 1.2-132.1; p=0.036), respectively, were significantly associated with the risk of deterioration of PNCV after 5 years. This study suggests that plasma cell adhesion molecules may play an important role in the development and progression of peripheral neuropathy in diabetes mellitus.

Adult↗
PubMed1997

Pathogenesis of hemorrhage induced by proteinase H from eastern diamondback rattlesnake (Crotalus adamanteus) venom.

The pathogenesis of hemorrhage of a purified hemorrhagic toxin, proteinase H from Crotalus adamanteus venom, was studied. Female, white CD-1 mice were injected intramuscularly with sublethal doses of the hemorrhagic toxin and tissue samples were obtained at 10 min, 1, 3 and 24 hr following injection. Severe local hemorrhage was observed grossly within 10 min. Hemorrhage was observed in the connective tissue of skeletal muscle and within adjacent adipose tissue. Many larger vessels were congested with erythrocytes and platelets. By 3 hr inflammatory cell infiltration was observed and necrosis of some muscle cells was evident. Transmission electron microscopy showed that the capillary endothelium was ruptured, leading to hemorrhage per rhexis. Capillary basal laminae were disorganized and often wholly or partially absent.

Animals↗
PubMed1997

Systemic hemorrhage induced by proteinase H from Crotalus adamanteus (eastern diamondback rattlesnake) venom.

The systemic effects of a purified hemorrhagic toxin, proteinase H, from Crotalus adamanteus venom, were studied. Female, white CD-1 mice were injected intravenously with proteinase H and tissue samples were obtained at 1, 3 and 24 hr after injection. Hemorrhage was observed grossly within 1 hr in several internal organs including the stomach and small intestine, the heart and the lungs. Surface discolorations thought to be petechial hemorrhages were observed in the kidneys. The livers of treated animals were visibly swollen and darkened and lobules were accentuated. Tissue samples were taken from the stomach, duodenum, heart, lungs, liver and kidneys and prepared for observation by light and electron microscopy. Frank hemorrhage was observed by light microscopy in the walls of the stomach and duodenum, in the myocardium and in the lungs. Pulmonary hemorrhage was severe, with involvement of nearly all of the pulmonary tissue within 3 hr. A1 doses of 5 micrograms/g, hepatic degeneration was observed by 3 hr. Renal glomeruli were noticeably swollen and the lumena of the proximal convoluted tubules indistinct. Closer examination by electron microscopy revealed that the endothelial cells comprising the fenestrated glomerular capillaries remained intact but signs of degeneration (i.e. cytoplasmic swelling and mitochondrial swelling) were observed. Proteinase H induces systemic hemorrhage in the heart, lungs, stomach and small intestine, renal glomerulonephropathy and hepatic degeneration.

Animals↗
PubMed1994

Treatment considerations in postmastectomy reconstruction: their relative importance and relationship to patient satisfaction.

Although studies concerning motivation for and satisfaction with breast reconstruction after mastectomy have proliferated, little information is available concerning the relative importance of motivating factors and satisfaction with treatment choice in nonreconstructed and reconstructed mastectomy patients. We studied this by questioning 144 women in four groups: mastectomy patients who had reconstruction; mastectomy patients who did not have reconstruction; and two control groups composed of women who had not had any cancer or who had undergone hysterectomy for uterine cancer. This study was conducted just before the reports of alleged risks of silicone to the patients and reflects the opinions of patients without such bias. This study shows that, although women who opted for reconstruction reported greater concern about appearance than women who did not have reconstruction, both groups described concerns about surgical discomfort and possible complications. Also, women's concerns about appearance did not seem to fall solely into public (others' evaluations) or private (patients' own evaluation) domains. Rather, personal attitudes about appearance may affect interpersonal experiences. Finally, concerns about the possibility of recurrence may reduce patient satisfaction for some women who have reconstruction, so postsurgical education regarding cancer risk may be needed. Reconstructed and nonreconstructed mastectomy patients do not appear to differ in postoperative behaviors promoting personal health. This information, analyzed before the silicone controversy, may serve as a baseline for future research on the impact of the silicone crisis on women's perceptions regarding reconstruction.

Adult↗
PubMed1993

Comparison of the immunogenicity and antigenic composition of ten Central American snake venoms.

The immunological reactivity of five crotaline antivenoms for the venoms of ten Costa Rican snakes was determined. Venoms from Bothrops asper, B. godmani, B. lateralis, B. nasutus, B. ophryomegas, B. schlegelii, B. nummifer, B. picadoi, Crotalus durissus durissus and Lachesis muta stenophrys were separated by SDS-PAGE, transferred to cellulose nitrate membrane and reacted against five different antivenoms. Antisera used in the immunoblotting were prepared in rabbits to the crotaline venoms from Crotalus viridis viridis (prairie rattlesnake), Crotalus durissus terrificus (South American rattlesnake), Crotalus atrox (western diamondback rattlesnake), and Bothrops atrox (fer de lance). SDS-PAGE analysis of the ten venoms indicated that all venoms had components in the high-medium mol. wt (> 15,000) and low mol. wt (< 15,000) range, but they all had at least twice as many components in the high-medium mol. wt range. The venoms of B. nummifer and B. nasutus have the greatest number of bands (24) whereas B. asper has the lowest (17). There appeared to be no difference in immunogenicity between high-medium mol. wt components and low mol. wt components; however, with the venoms of B. nasutus, B. ophryomegas, and B. schlegelii, there were few reactions between antivenoms and low mol. wt components. Half of the ten venoms tested had the highest reactivity with antivenom against B. atrox venom. Two venoms reacted most with antivenom against C. adamanteus venom; one with antivenom to C. atrox venom; one with antivenom to C. v. viridis venom and one with antivenom to C. d. terrificus venom.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Neonatal gram negative meningitis: a 10-year review, with reference to outcome and relapse of infection.

Twenty-four infants treated for neonatal Gram negative bacillary meningitis over a 10-year period were reviewed to determine the mortality and incidence of complications including relapse. Nine (37.5%) infants died; two survivors had major and 13 minimal or no handicap. Five (21%) infants had a relapse of meningitis after the initial course of treatment; two of these infants had been treated with cefotaxime. The outcome did not correlate with age, sex, gestation, cerebrospinal fluid (CSF) parameters or peripheral neutrophil counts. A poor outcome was associated with thrombocytopenia, persistence of viable organisms in the CSF for more than 24 h and with seizures, particularly in infants aged 7 days or less. There were no clinical or laboratory parameters predictive of subsequent relapse and there was no apparent relationship with choice or dose of antibiotic used or duration of treatment.

Cefotaxime↗
PubMed1984

The wavering midline: a diagnostic sign of fetal hydrocephalus.

The significance of midline wavering in the central nervous system as a diagnostic sign in hydrocephalus was evaluated prospectively in 27 hydrocephalic fetuses. No normal fetuses in a control group exhibited a wavering midline at three different times in pregnancy. Wavering along the entire length of the midline was seen in all 27 affected infants with hydrocephalus diagnosed from 12 to 42 weeks' gestation, prior to determination of an abnormal lateral ventricular width:hemispheric width ratio in one of 23 cases for which data were available and prior to an increased biparietal diameter in 25 (48%). One fetus, not included in the series, showed wavering of the midline echo and had an abnormal lateral ventricular width:hemispheric width ratio. The neonate was later shown to have trisomy 21 (47,XY,+21) and is suspected to have had a transient ventriculomegaly. Wavering along the complete length of the midline echo appears to be a constant finding in hydrocephalus in the fetus.

Adult↗