Biomedical subjects
Publications and source records attributed to H King.
Pericardial adhesions pose a major problem during reoperative cardiac surgical procedures. The purpose of this study was to determine the effect of intrapericardial dextran 70 on the formation of pericardial adhesions in an animal model. The data obtained revealed that intrapericardial dextran 70 reduced the incidence of experimental pericardial adhesions.
The association between the prevalence of diabetes and three suspected risk factors--overweight, physical inactivity, and urbanization--has been studied in 5519 subjects from three Pacific populations: Melanesians and migrant Asian Indians in Fiji in 1980, and Micronesians in the Republic of Kiribati (formerly the Gilbert Islands) in 1981. Associations were found to be inconsistent between populations, and between the sexes within populations. In some cases, overweight was strongly associated with prevalence; in others, the principal variable associated with diabetes appeared to be physical inactivity. More than one factor was associated with increased risk in Micronesians, and some evidence of interaction between factors also emerged. Although longitudinal studies will be required for the complete elucidation of risk factors for diabetes, these findings suggest that risk factors may be heterogeneous in their effect upon different populations, and that an assessment of risk variables operating in a given target community may be of value in the initial phase of a diabetes prevention or control program.
Explore the source record for details and available documents.
Two urbanized Micronesian populations were recently studied by population-based diabetes surveys. These were Nauruans living on the island of Nauru, and Gilbertese resident on the islet of Betio, in the Republic of Kiribati (1982 and 1981, respectively). Nauruans are known to suffer from a very high prevalence of non-insulin-dependent (type II) diabetes mellitus (NIDDM). In the present study, the effects of suspected environmental risk factors for diabetes were controlled for, in an attempt to elucidate any residual difference in the prevalence of diabetes between the two groups, which might be of genetic origin. As almost all Nauruans lead a physically inactive lifestyle, only inactive subjects in either population were selected for study. The total study sample consisted of 2306 subjects. After further controlling for the effects of age and obesity, the odds of diabetes for Nauruans, as compared with Gilbertese, were threefold. The multiple logistic regression model showed ethnicity (i.e., being Nauruan) to be the strongest of the predictor variables examined in both sexes. In a random subsample of approximately one-third of the total subjects (N = 694), stratified with respect to age and sex, daily intake of total energy and of three dietary components was assessed. The dietary variables were carbohydrate, fat, and dietary fiber. Fat intake was found to be a weak, but significant predictor of diabetes in females after controlling for age, although dietary fat was not predictive of diabetes after also controlling for ethnicity, or for body mass. None of the other dietary variables had any predictive power in either sex.(ABSTRACT TRUNCATED AT 250 WORDS)
A diabetes survey was conducted in the highlands of Papua New Guinea in June 1983. Two villages in the Asaro Valley, Eastern Highlands Province, were selected for study. The subjects were of Melanesian ancestry, and were free of Austronesian genetic admixture. The response rate was 95% and 308 subjects were examined. As defined by current WHO criteria, there was a total absence of non-insulin-dependent diabetes (NIDDM) in these communities. The prevalence of impaired glucose tolerance (IGT) was 2%. These estimates of glucose intolerance are the lowest yet to be reported from the Pacific, using currently accepted diagnostic criteria and standardized survey methods. The 2-hr plasma glucose and insulin concentrations were positively correlated in both sexes. Of the two villages studied, one had undergone a greater degree of acculturation than the other. Both the total distribution and the mean value of 2-hr plasma glucose concentration were lower in the more traditional village, and these findings could not be explained by differences in age or obesity between the two communities. Mean 2-hr plasma insulin concentration did not differ significantly between the two villages, and was very low in both. The results of this study support the theory that Melanesians free of Austronesian genetic admixture are relatively, though not absolutely resistant to the deleterious influence of acculturation upon glucose tolerance seen in other Pacific populations. However, the notion that in this population cultural change has been insufficient, or of too recent onset for a deterioration in glucose tolerance to be manifest cannot be excluded.
A population survey in 1982 has confirmed that Nauruan adults suffer from an extremely high prevalence of Type 2 (noninsulin-dependent) diabetes mellitus. The crude population prevalence of Type 2 diabetes was 24%. Abnormal glucose tolerance (impaired glucose tolerance and diabetes) was present in over 40% of the adult population and exceeded 80% in both sexes after the age of 55 yr. Diabetic retinopathy was present in 24% of diabetic patients, confirming that this Micronesian population is susceptible to the microvascular consequences of hyperglycaemia. Subjects with impaired glucose tolerance had a prevalence of retinopathy three times that of normal subjects, though the difference did not reach statistical significance. Prevalence of retinopathy was substantially higher in diabetic patients than either normal subjects or those with impaired glucose tolerance.
Explore the source record for details and available documents.
An epidemiologic survey of the whole adult Micronesian population of Nauru in the Central Pacific conducted in 1982 has confirmed that Nauruans, along with Pima Indians, suffer the highest rate of abnormal glucose tolerance yet recorded. To establish the morbid effects of hyperglycemia in this population, all responders to the diabetes survey were concurrently examined for diabetic retinopathy. In diabetic subjects, the crude prevalence of retinopathy was 24%. Specific rates were determined at various levels of the following characteristics: age, two-hour post-load plasma glucose, body mass index, duration of diabetes, and systolic blood pressure. Prevalence was found to rise with increasing two-hour plasma glucose and duration, to fall with increasing body mass index, and to have a quadratic relationship with age and systolic blood pressure. The multiple logistic regression model was used to determine whether the selected characteristics were significant in increasing the risk of retinopathy. Body mass index and systolic blood pressure did not contribute significantly to this risk after controlling for age. Increasing two-hour plasma glucose significantly increased the risk of retinopathy, and duration of disease was the strongest predictor variable. This study shows that the consequences of hyperglycemia in this Micronesian population are comparable to those already documented in European and American Indian communities.
Rural-urban and ethnic comparisons of impaired glucose tolerance and diabetes mellitus were made in the biracial population of Fiji in 1980. No statistically significant differences existed in age-standardized impaired glucose tolerance prevalence between rural and urban groups or between Melanesians and Indians. The age-standardized prevalence of diabetes in the rural Melanesian male population was one-third that of the urban male population (1.1 vs. 3.5%). In females, there was a sixfold rural-urban difference (1.2 vs. 7.1%). By contrast, rural and urban Indians had similar rates (12.1 vs. 12.9% for males; 11.3 vs. 11.0% for females). Standardization of two-hour plasma glucose for age and obesity did not eliminate the rural-urban difference in plasma glucose concentration for Melanesian males and females. The results in Melanesians confirm previously reported rural-urban diabetes prevalence differences, and suggest that factors other than obesity, such as differences in physical activity, diet, stress, or other, as yet undetermined, factors contribute to this difference. The absence of a rural-urban difference in diabetes prevalence in Indians may suggest that genetic factors are more important for producing diabetes in this ethnic group, or that causative environmental factors such as diet operate similarly upon both the rural and the urban populations.
Extension of the normal thymus into the posterior mediastinum is rare. The CT appearance of this anomaly in an infant is presented. A mass of soft-tissue density extended from the anterior mediastinum to the posterior chest wall. The absence of any tissue-cleavage plane in the lesion and a smooth continuous lateral margin are signs of posterior extension of the thymus, and they help to distinguish this from a normal anterior thymus being present with a posterior tumor.
A recent epidemiological survey of the whole adult Micronesian population of Nauru has confirmed that Nauruans, along with Pima Indians, suffer the highest rate of abnormal glucose tolerance yet recorded. To establish the morbid effects of hyperglycaemia in this population, all responders to the diabetes survey were concurrently examined for diabetic retinopathy. In diabetic subjects, the crude prevalence of retinopathy was 24%. Specific rates were determined at various levels of the following characteristics: age, 2 hour post-load plasma glucose, body mass index, duration of diabetes and systolic blood pressure. Prevalence was found to rise with increasing 2 hour plasma glucose and duration, to fall with increasing body mass index and to have a quadratic relationship with age and systolic blood pressure. The multiple logistic regression model was used to determine whether the selected characteristics were significant in increasing the risk of retinopathy. Body mass index and systolic blood pressure did not contribute significantly to this risk after controlling for age. Increasing 2 hour plasma glucose significantly increased the risk of retinopathy, and duration of disease was the strongest predictor variable. This study shows that the consequences of hyperglycaemia in this Micronesian population are comparable to those already documented in European and American Indian communities.
Explore the source record for details and available documents.
Most epidemiological studies of diabetic retinopathy have been based on clinic populations. This produces a bias for the more severe cases and later stages of the disease. To avoid this bias, 1567 Micronesian adults of Nauru (82% of total adult population) were examined. Diabetic retinopathy was classified by both the World Health Organization (WHO) criteria and the Airlie House reference photographs. Results were subject to multiple logistic regression model analysis. Diabetic retinopathy was present in 7% of the general population and in 24% of diabetics. Of the signs, microaneurysms and microhaemorrhages were the most important, being present alone in 19.5%; and in 68.1% when associated with exudates. Proliferative retinopathy was present in 4.5% of cases. Exudates alone were found in two cases (2.2%). Duration of diabetes was the strongest predictor variable and increasing two-hour plasma glucose levels significantly increased the risk of developing retinopathy.
Extracardiac conduits are essential in operations for congenital discontinuity between the right ventricle and the pulmonary artery. The disturbing degree of obstruction reported in clinical series of extracardiac conduits containing porcine valves has been attributed in part to early valve deterioration and the development of a thick neonintimal lining within the Dacron graft. This study compares the hemodynamic differences and the thickness of the neointimal lining in right ventricular extracardiac conduits with and without a porcine valve. Woven Dacron conduits (16 mm) were implanted in 15 adult mongrel dogs, and then the proximal pulmonary artery was occluded with Dacron tape. In six dogs, the extracardiac conduit contained a porcine valve, whereas in the other nine it did not. Cardiac output, transconduit gradient, and resistance were measured at operation and 6 and 12 months postoperatively in both groups. No hemodynamic differences were noted. After 1 year, the thickness of the neointimal lining was threefold greater in valved conduits (1,370 +/- 313.1 mu versus 367 +/- 28.07 mu, p less than 0.005). The neointima along the Dacron graft was thickest proximal and distal to the porcine valve. The luminal peel in valved conduits contained fenestrations and intimal flaps, similar to those observed clinically. In our model, a porcine valve in a right ventricular extracardiac conduit is associated with intimal hyperplasia not seen in nonvalved conduits. If the pulmonary vascular resistance is normal, then the absence of a valve within the conduit does not significantly change hemodynamics and may warrant clinical application to prevent late conduit obstruction.
Two hundred and thirty-two strains of Escherichia coli belonging to infantile enteropathogenic serotypes isolated in the United Kingdom during 1980 and 1981 were tested for resistance to 10 antimicrobial drugs. Resistance to one or more drugs was found in 134 (57.8%) of the strains, with resistance to sulphonamides, streptomycin, tetracycline, and ampicillin occurring most commonly. Resistance was transferable in 65 out of 104 resistant strains. These findings are a cause for concern because they indicate that the choice of treatment for severe illness is limited and suggest that a large pool of drug-resistant organisms exists in the community.
The superior vena cava (SVC) and thoracic inferior vena cava (IVC) were replaced in 46 dogs with autologous vein, knitted Dacron, glutaraldehyde-fixed porcine pericardium, unsupported polytetrafluorethylene (PTFE), and externally stented PTFE. After 30 days, patency rates were determined by contrast venography and were 100%, 9%, 50%, 75%, and 100%, respectively. The patency rates of Dacron and glutaraldehyde-fixed pericardium are considered unacceptable when compared to autologous vein (p less than 0.05). Stented PTFE exhibited a patency rate equal to that of autologous vein at 30 days, minimal graft reaction, excellent incorporation by host fibroblasts, and a smooth neointima. The external spiral support added to PTFE enchanced the thromboresistance of this graft in the thoracic venous system. Long-term follow-up is required to determine if the stented PTFE prosthesis remains comparable to autologous vein as a venous conduit.
Transthoracic diaphragmatic plication is a simple and effective means of treatment for phrenic nerve injury and resultant diaphragmatic paralysis, and should be undertaken as soon as the diagnosis of diaphragmatic paralysis is established in a child with substantial respiratory difficulty. Seven of more than 1,500 patients sustained phrenic nerve injury during operation for congenital heart disease at our institution over the past five years. All but 1 patient were less than 5 months old, and the average weight was 3.8 kg. Five of the 7 could not be weaned from the ventilator, and the other 2 had persistent postoperative tachypnea and stridor. Before 1980, 3 patients were intubated for an average of 16 days prior to diagnosis by fluoroscopy. Since then, 4 patients have been intubated for an average of 7.8 days before diagnosis. All 7 underwent transthoracic diaphragmatic plication and were extubated by 6 days after operation (mean, 3.7 days). Six patients survived and are doing well. The 1 death occurred in 1976 in a premature infant with multiple congenital cardiac lesions; diagnosis was delayed until the twenty-eighth day after intubation and transthoracic diaphragmatic plication, until the sixty-second day. This infant died of pneumonia one month after extubation. These data support our policy of establishing an early diagnosis of phrenic nerve injury and early treatment utilizing transthoracic diaphragmatic plication in symptomatic children.
Major advances have been made in the treatment of congenital heart disease in the past 10 years. Management of the 20 per cent of children who become critically ill during the first 3 months of life remains a major challenge because they represent the most extreme anatomic and physiologic derangements. A review of the recent data accumulated in the NERICP showed an overall mortality of 54 per cent in infants presenting for surgery in the first 2 months of life. We have reviewed our experience with over 400 procedures during the past 5 years in infants less than three months of age, and our overall mortality is 19 per cent. Primary repair remains our goal, but a disappointingly high mortality with primary repair in this group, by us and others, has caused us to perform palliative procedures when palliation in our experience offers an overall lower mortality.