Search PubMed⌕ Search

Biomedical subjects

A Green

Publications and source records attributed to A Green.

At least 271 records · Page 15Linked to original sources
PubMed1996

Trends in the epidemiology of IDDM during 1970-2020 in Fyn County, Denmark.

OBJECTIVE: To present an epidemiological model applicable to diabetes based on which prevalence rates are estimated from assumed rates of incidence and mortality of diabetes. Furthermore, this study illustrates the model by analyzing epidemiological data on IDDM in a Danish population during 1970-1990, with predictions of prevalence rates for 1990-2020. RESEARCH DESIGN AND METHODS: The epidemiological model assumes known prevalence rates as well as incidence rates and mortality at a given time. Under assumed rates of incidence and mortality of IDDM and its complications, the prevalence rate is the dependent variable, estimated as a function of calendar time. We use epidemiological data on IDDM (operationally defined as insulin-treated diabetes with onset before age 30 years), blindness, and nephropathy, as well as mortality, as reported for 1973 and 1987 in Fyn County, Denmark. RESULTS: During 1970-1990, the prevalence of IDDM increased steadily because of increasing incidence and decreasing risk of complications and mortality. The relative prevalence of patients with nephropathy increased, whereas that of blind patients decreased considerably. Under specified assumptions regarding the future levels of incidence of disease, complications, and mortality, it is estimated that the prevalence rate of IDDM in the year 2020 will be 45-60% higher than the level in the year 1990. The relative prevalence of patients with nephropathy will increase further, whereas the relative prevalence of blind patients will remain constant at a low level. CONCLUSIONS: IDDM will represent an increasing public health problem in Denmark during the next decades, with increasing overall prevalence rates and a rising proportion of patients with nephropathy. The major determinant of this trend is increasing incidence combined with declining mortality and declining risk of complications. It is strongly recommended that epidemiological models like the one presented here be further developed and implemented at regional levels to provide data for the dimensioning of the current and future diabetes care systems.

Adolescent↗
PubMed1996

Perioperative risk factors for wound infections after lower back fusions.

Although reduced by technology, antibiotics and surgical technique, spinal infection from surgery remains a recognizable risk. The rate of infection in spinal surgery is reviewed. Identification of risk factors are important in preoperative planning. Preoperative risk factors for postoperative spinal infection include obesity and smoking. Attention to sterility and efficient technique can reduce potential wound contamination intraoperatively. Excessive wound drainage and seroma formation should warn of a potential wound infection.

Adult↗
PubMed1996

The Danish Conscription Registry: a resource for epidemiological research.

According to the Danish constitution all Danish male citizens must appear before a Conscript Board for assessment prior to military or civil service. Conscript Board examinations have followed the same standardized procedures over many decades, and the Danish Conscript Registry represents a valuable resource for epidemiological research in Denmark. During the last two decades investigations based on information in the registry have produced significant contributions to many areas of medical science. Within the last decade new procedures and electronic data processing and storage have resulted in restricted possibilities concerning current and future utilization of the Danish Conscript Registry for epidemiological purposes. To improve this it is recommended to maintain all codes describing present illnesses and conditions together with the civic registration numbers in the computerized archive of all subjects assessed by the Conscript Board.

Adolescent↗
PubMed1995

Incidence of cutaneous childhood melanoma in Queensland, Australia.

The incidence of cutaneous melanoma in children aged 0-14 years was examined in Queensland, Australia. Details of notifications were collected from the population-based Australian Paediatric Cancer Registry. Between 1987 and 1994, the age-adjusted incidence rates of invasive cutaneous melanoma occurring in Queensland children were estimated at 8.5/million for males and 7.1/million for females. Incidence rates rose steeply in both sexes with increasing age, from less than 1/million in the 0-4 age group, to nearly 30/million in the 10-14 age group. To assess the uniformity of the anatomical distribution of lesions, relative tumour densities (RTDs) were calculated compared with the body as a whole. In both sexes, melanomas were most common on the trunk (RTD > 3), while lower limb lesions were less common (RTD < 0.6) and no melanomas were reported on the buttocks or external genitalia. Although not statistically significant, there was a tendency for truncal lesions in males to occur on the back, while in females, truncal melanomas were more evenly distributed across the chest, back and shoulders. No consistent relationship between latitude and melanoma incidence was observed, with higher rates reported in the subtropical than the tropical regions of Queensland. These are the first reported incidence rates of cutaneous melanoma in Australian children and are the highest ever reported in the world in this age group. Our findings provide baseline data from which to monitor changes in the occurrence of cutaneous melanoma in children.

Adolescent↗
PubMed1995

Concordance rates of insulin dependent diabetes mellitus: a population based study of young Danish twins.

OBJECTIVE: To study the genetic contribution to the aetiology of insulin dependent diabetes mellitus. DESIGN: Historical cohort study of twins, with information on diabetes being gathered by questionnaire, verification of the diagnosis by the subject's diabetologist or general practitioner, and clinical examination in available twins. SETTING: Danish twin register and diabetic clinics and general practices throughout Denmark. SUBJECTS: 20,888 twin pairs born during 1953-82, included in a population based nationwide register. MAIN OUTCOME MEASURES: Crude and cumulative concordance rates and heritability in monozygotic and dizygotic twins. RESULTS: The crude probandwise concordance rate was 0.53 (95% confidence interval 0.33 to 0.73) for monozygotic twin pairs and 0.11 (0.05 to 0.21) for dizygotic twin pairs. When adjusted for age at onset of diabetes and age at last observation among unaffected twin partners the cumulative proband-wise risk from birth to age 35 was estimated as 0.70 (0.45 to 0.95) for monozygotic twins and 0.13 (0.05 to 0.20) for dizygotic twins. The correlations of liability for monozygotic and dizygotic twin pairs were estimated as 0.96 (SE 0.09) and 0.58 (0.07), with a heritability estimate of 0.72 (0.21). CONCLUSIONS: The risk of insulin dependent diabetes in monozygotic twins is higher than previously thought and for dizygotic twins is higher than in ordinary first degree relatives. Based on the findings of this study the genetic component to the disease seems more important than hitherto believed.

Cohort Studies↗
PubMed1995

Reproductive and other factors and risk of epithelial ovarian cancer: an Australian case-control study. Survey of Women's Health Study Group.

Of the few factors known to be associated with epithelial ovarian cancer, the most consistently observed relate to women's reproductive function, although even here uncertainties remain. We have undertaken a case-control study involving personal interviews with over 1,600 women, the largest of its kind to date, to investigate further the associations between women's reproductive histories and other factors and the development of ovarian cancer. Cases were drawn from women diagnosed with epithelial ovarian cancer in 3 Australian states, Queensland, New South Wales and Victoria, between August 1990 and December 1993, and controls were drawn at random from the electoral roll, stratified by age and geographic region. Trained interviewers administered standard questionnaires to obtain detailed information about women's reproductive and contraceptive histories and other factors of interest, such as smoking and family history of ovarian or other cancer. Findings were based on data from 824 cases and 860 controls and confirmed the reduced risk of ovarian cancer associated with increasing parity and duration of use of the oral contraceptive pill (OCP), hysterectomy and tubal ligation. The strongest association of all was seen with use of the OCP for 10 years or more. An inverse association between ovarian cancer and age at first birth was observed, but this was not statistically significant. There were no associations between development of ovarian cancer and number of incomplete pregnancies, use of hormone replacement therapy or menstrual history. Among other factors considered, education after leaving school was negatively associated and high body mass index, family history of ovarian cancer, use of talc in the abdominal or perineal region and smoking were positively associated with occurrence of ovarian cancer.

Adolescent↗
PubMed1995

Risk of cutaneous melanoma associated with pigmentation characteristics and freckling: systematic overview of 10 case-control studies. The International Melanoma Analysis Group (IMAGE).

Using individual subject data from 10 case-control studies, comprising over 3000 cases and almost 4000 controls, we have estimated the relative risk of melanoma associated with aspects of complexion, namely, hair, eye and skin colour and freckling in adulthood, and have examined the relationships between these factors and naevus count in terms of melanoma risk. Compared with individuals with black or dark brown hair, the relative risks for developing melanoma in those with light brown, blonde and red hair were 1.49 (95% CI 1.31, 1.70), 1.84 (95% CI 1.54, 2.21) and 2.38 (95% CI 1.90, 2.97), respectively. Individuals with blue eyes had a risk 1.55 (95% CI 1.35, 1.78) times that for those with brown eyes, or 1.15 (95% CI 0.94, 1.40) after adjusting for hair colour and freckling in adulthood. The relative risks associated with hair and eye colour were independent of those for naevus count and skin colour. Light skin colour and high freckle density were also highly significant risk factors, independent of each other and of naevus count and hair and eye colour. The risks associated with these factors, while individually modest, are largely independent, and thus pigmentation characteristics and freckling tendency should be useful in identifying high risk groups to be targeted for prevention.

Case-Control Studies↗
PubMed1995

Risk of cutaneous melanoma associated with a family history of the disease. The International Melanoma Analysis Group (IMAGE).

In a combined analysis of 2952 melanoma patients and 3618 controls from 8 case-control studies in white populations the risk of cutaneous melanoma was 2.24-fold higher (95% CI, 1.76-2.86) in subjects who reported at least one affected first-degree relative than in subjects who did not. There was no evidence for heterogeneity in the relative risk between the studies, which were from a wide range of latitudes and hence degrees of sun exposure. The effect of family history on melanoma risk was independent of age, naevus count, hair and eye colour, and freckling. There was no evidence for a relationship between family history and primary site of melanoma but there was some suggestion that the familial patients were more likely to have superficial spreading melanoma or lentigo maligna melanoma than acral lentiginous melanoma or nodular melanoma.

Case-Control Studies↗
PubMed1995

Different mechanisms of hydroxylation site selection by liver and kidney cytochrome P450 species (CYP27 and CYP24) involved in vitamin D metabolism.

A series of homologated 1 alpha-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 molecules with one to three extra carbons in the side chain were used to examine the substrate preferences and hydroxylation site selection mechanisms of the liver vitamin D3-25-hydroxylase (CYP27) and the target cell 25-hydroxyvitamin D3-24-hydroxylase (CYP24). Cultured and transfected cell models, used as sources of these hydroxylases, gave 23-, 24-, 25-, and 27-hydroxylated metabolites which were identified by their high performance liquid chromatography and GC-MS characteristics. Lengthening the side chain is tolerated by each cytochrome P450 isoform such that 25-hydroxylation or 24-hydroxylation continues to occur at the same rate as in the native side chain, while the site of hydroxylation remains the same for the liver enzyme in that CYP27 continues to hydroxylate at C-25 and C-27 (minor) despite the two-carbon-atom extension. Somewhat surprising is the finding that C-24 and C-23 (minor) hydroxylations also do not change as the side chain is extended by as much as three carbons. We conclude that CYP24 must be directed to its hydroxylation site(s) by the distance of carbon 24 from the vitamin D ring structure and not as in CYP27 by the distance of the hydroxylation site from the end of the side chain.

Calcitriol↗
PubMed1995

Gi down-regulation and heterologous desensitization in adipocytes after treatment with the alpha 2-agonist UK 14304.

Prolonged treatment of rat adipocytes with the A1-adenosine receptor agonist [-]N(6)-phenylisopropyl adenosine (PIA) or prostaglandin E1 down-regulates Gi and induces heterologous desensitization. alpha 2-Adrenergic receptors also inhibit adenylyl cyclase through Gi, but whether alpha 2-receptors are present on rat adipocytes has been controversial. We have investigated the effects of the highly specific alpha 2-adrenergic agonist UK 14304 (5-bromo-6-[2-imidazolin-2-ylamino]-quinoxaline) on rat adipocytes. In previous studies on young rats, we were unable to demonstrate an effect of the alpha 2-agonist. We now report that, in cells isolated from older, more obese rats (300-400 g), UK 14304 inhibited lipolysis (measured as the rate of glycerol release) by approximately 40% (EC50 approximately 40 nM). To determine whether UK 14304 would induce heterologous desensitization, we incubated adipocytes with or without 1 microM UK 14304 for 4 days in primary culture. The cells were then washed, and the rate of lipolysis was determined during a 30-min incubation in the presence of various concentrations of PIA. The concentration-response curve for PIA-induced inhibition of lipolysis was shifted to the right, with the EC50 for UK 14304-treated cells about 2-fold higher than in the control cells. This finding demonstrates that the alpha 2-agonist can desensitize the response to PIA and indicates heterologous desensitization. To investigate the mechanism of this phenomenon, we isolated crude membrane fractions from the cells and analyzed them on Western blots using antibodies against Gi alpha 1, 2 and 3. In cells treated with UK 14304 for 4 days, Gi1 alpha and Gi2 alpha were down-regulated to about 15% of the control level, and Gi3 alpha was decreased to 30% of control. We conclude that prolonged treatment of adipocytes with the alpha 2-agonist induces heterologous desensitization of lipolysis and causes down-regulation of Gi. The findings suggest that G-protein down-regulation is a mechanism for heterologous desensitization.

Adipocytes↗
PubMed1995

Factors which influence alterations of phosphates and pH in exercising human skeletal muscle: measurement error, reproducibility, and effects of fasting, carbohydrate loading, and metabolic acidosis.

Previous studies have shown considerable variability in the metabolic response of human skeletal muscle during a standardized exercise protocol. The goal of these studies was to investigate the factors responsible for the broad range of metabolic changes produced by fatiguing exercise. Experiments were performed to quantitate the measurement error of 31P nuclear magnetic resonance spectroscopy of human muscle, the reproducibility of changes within a single subject, and the effects of fasting, carbohydrate loading, and metabolic acidosis. The results show that none of these factors appear to be responsible for the wide variation between subjects. However, the effects of training and genetic factors were not investigated and are likely to be responsible for the substantial variability between subjects.

Acidosis↗
PubMed1995

Prenatal exclusion of the HHH syndrome.

Prenatal diagnosis of the hyperornithinaemia, hyperammonaemia, and homocitrullinuria syndrome is described by the analysis of ornithine incorporation in second-trimester cultured amniotic fluid cells. An unaffected fetus was predicted and confirmed in the newborn child. This is the third reported prenatal diagnosis for this disorder and the second predicting an unaffected fetus.

Amino Acid Metabolism, Inborn Errors↗
PubMed1995

A misdiagnosis of X-linked adrenoleukodystrophy in cultured chorionic villus cells by the measurement of very long chain fatty acids.

A case is reported of a male fetus at risk of X-linked adrenoleucodystrophy who showed a normal cultured chorionic villus cell very long chain fatty acid (VLCFA) profile but at birth exhibited grossly abnormal plasma and cultured fibroblast VLCFAs. Maternal contamination or a sample mix-up was excluded by chromosome analysis and analysis of polymorphic markers. This is the second report of a fetus affected with this disorder who showed normal cultured chorionic villus cell VLCFAs. It highlights the importance of a proper audit of all prenatal diagnoses to evaluate method reliability.

Adrenoleukodystrophy↗