Biomedical subjects
J K Davidson
Publications and source records attributed to J K Davidson.
Magnification lymphography.
Magnification lymphography was performed on 37 patients, 22 of whom were suffering from bladder carcinoma, and compared with non-magnification lymphograms by two observers independently. The magnification lymphograms were performed on a Siemens Microfocus Bi 125/3/50 RG tube with a 0.1 mm focal spot. In six of the 37 patients (16%) significant extra information was found on the magnification lymphograms compared to the non-magnification lymphograms. In 31 out of 37 patients (84%), the intranodal detail shown was better in the magnification radiographs. Against the additional information gained must be weighed the disadvantages of magnification lymphography which include increased radiation dose, lengthening of procedure time, increased cost and the critical nature of exposure factors. In conclusion, magnification lymphography has a place and the disadvantages seem to be outweighed by the advantages.
Renal osteodystrophy: an underdiagnosed condition.
With the availability of 1-alpha-hydroxycholecalciferol it is even more relevant to detect the earliest stages of renal osteodystrophy. Sixty-two patients, either on haemodialysis or recent recipients of a renal transplant and 10 controls underwent hand radiography by a standard technique and by a direct magnification technique employing a 0.1 mm focal spot. A comparison of intracortical striations, subperiosteal resorption and soft tissue calcification was made in the two groups and hand score calculated on the non-magnification radiographs. The results were assessed independently by two radiologists. In subperiosteal resorption, the non-magnification technique gave a 6% positive result compared to 47% with magnification (P less than 0.01). For intracortical striations, the non-magnification technique gave an 11% positive results, whereas magnification resulted in a 45% positive result (P less than 0.01). Soft tissue calcification was found in one patient only, and reduction in hand score was a rare occurrence. The use of a standard technique only, without magnification, for radiographing hands in patients with renal disease, will result in evidence of renal osteodystrophy being missed in a significant proportion of patients.
Newer approaches to diet management of diabetes: calorie control.
Explore the source record for details and available documents.
Magnification renal arteriography.
Magnification selective renal arteriograms were performed on 24 patients, 12 of whom were hypertensive, and compared with non-magnification arteriograms by two observers independently. The magnification angiograms were performed on a Siemens Microfocus Bi 125/3/50 RG tube with a 0.1 mm focal spot. Of the 24 patients examined, information crucial to the diagnosis was found only on the magnification films in three patients (12.5%). Extra information compared with the nonmagnification films was found in the magnification films in 12 patients (50%). No additional information was discovered in the remaining nine patients (37.5%). The magnification angiograms enabled the interlobular vessels to be visualized--this was not possible on the non-magnification films. Against the additional information gained must be weighed the disadvantages of magnification arteriography which include increased radiation dose and lengthening of procedure time plus additional injections of contrast. In conclusion, there is a place for magnification renal arteriography and the advantages seem to outweigh the disadvantages.
Spin-off cost/benefits of expanded nutritional care.
Eight years ago, in caring for persons with diabetes at Grady Memorial Hospital, Atlanta, priority was given to the use of oral hypoglycemic agents and insulin, with only minimal attention to nutrition. In 1971, an "expanded nutritional care program" was instituted, with emphasis on nutritional education and follow-up. Use of oral agents was discontinued, and, since 1972, less insulin has been used. The new dietary program, with dietitians playing a key role, includes a one-week total fast, stringent low-calorie diets, individualized dietary planning and instruction, and careful follow-up monitoring. Comparative pre-1971 and current data show: a 50 per cent reduction in lower extremity amputations, less diabetic ketoacidosis, fewer hospitalizations, weight reduction of 40 per cent with no increase in plasma glucose (in a 127-patient cohort with complete follow-up), and a savings to the hospital of more than $96,000 in the cost of medications and $3,700,000 in hospitalizations in eight years.
Shortage specialties: radiology.
Explore the source record for details and available documents.
Immunologic insulin resistance.
The efficacy of sulfated beef insulin for plasma glucose control in 35 patients with immunologic insulin resistance was studied. Patients were on a mean dose of 550 U./day (range 200--2,000) of U-500 regular beef insulin. Mean maximum 125I-insulin-binding capacity was 191 mU./ml. serum (range 13--1,080). Mean in vivo half-life (T 1/2) of 125I-regular beef insulin was 614 minutes (range 114--1,300), as against a mean T 1/2 of 13.9 minutes (range 11.8--16.5) in normal controls. Treatment was successful in 34 patients and unsuccessful in one with lipoatrophic diabetes. The mean initial dose of sulfated insulin was 89 U./day (range 15--400) and at three months was 66 U./day (range 20--400). Twenty-eight patients who responded and survived have been on sulfated insulin for a mean of 39 months (range 2-66) and are on a mean dose of 25 U./day (range 0--100). The mean maximum binding capacity fell to 9 mU./ml. (range 0--34) during therapy (p less than 0.01). Mean 125I-insulin T 1/2 fell from 614 to 249 minutes after sulfated insulin therapy (p less than 0.001). A comparative study of 15 patients on consecutive days showed a 35 sulfated insulin T 1/2 of 60 minutes (range 15--94) and a mean 125I-regular insulin T 1/2 of 246 minutes (range 62--560, p less than 0.001). These results indicate that sulfated insulin is less antigenic than regular beef insulin and combines less avidly with human antibodies to regular beef insulin. The response to sulfated insulin therapy was significantly better than the response reported by other investigators to pork insulin or to steroid therapy in similar patients.
Diabetes screening using a quantitative urine glucose method.
Explore the source record for details and available documents.
The significance of bone islands, cystic areas and sclerotic areas in dysbaric osteonecrosis.
Dysbaric osteonecrosis is a major hazard to compressed air workers and an increasing hazard to divers. Symptomless osteonecrosis is best recognised by radiology and it is of fundamental importance that interpretation be reliable and accurate. There is much controversy concerning the significance of bone islands and cystic areas; several authors report bone islands and cystic areas to be up to eight times more frequent in compressed air workers and divers and believe that these represent positive evidence of osteonecrosis. Skeletal radiographs of 100 Royal Navy divers, all of whom were at risk to osteonecrosis were matched for age and rank with 100 controls, none of whom had been exposed to high pressures. The radiographs were interpreted by three radiologists working independently without knowing whether the radiographs were in the diving or control group. It is concluded that bone islands, cystic areas and sclerotic areas, as described in this text, occur with equal frequency in divers as in the normal population and do not represent positive evidence of osteonecrosis. The report includes autopsy studies of the proximal femur and proximal humerus in six diving fatalities. Five bone islands in the proximal humerus and one in the femoral neck were studied in bones removed from five divers. In the sixth case a cyst was seen to develop radiologically in the femoral neck and then reduce in size over 3 years and 10 months. Slab radiographs and histological section in all cases show no evidence of osteonecrosis.
Traumatic osteonecrosis of the femoral head following intracapsular fracture: incidence and earliest radiological features.
A sub-capital fracture of the femoral neck is common particularly in the elderly female with non-union occurring in 25% and osteonecrosis in up to 24% of united fractures. Assessment of the viability of the femoral head in the early stages is unreliable and initial diagnosis of osteonecrosis depends on recognition of radiological features. Many reports imply that structural failure of the joint surface is the initial abnormality. 121 patients with a sub-capital fracture have been followed up for at least a year and as long as three and a half years. The incidence of osteonecrosis was 8% in Grade I fractures; 4% in Grade II and 21% and 30% in the more severe Grade III and Grade IV fractures. Of the 24 patients with osteonecrosis, increased radiological density developed in 13 at a time interval of 3 months to 36 months after the fracture with a mean time of 10 months and seven subsequently developed structural failure. Eleven patients developed structural failure as an initial feature at a time interval of 5 months to 24 months with a mean of 13 months. From this it is clear that either an absolute increase in radiographic density or structural failure are the earliest radiological features. Good quality radiographs, clearly demonstrating trabecular detail, are essential for the recognition of osteonecrosis.
Evaluation of diabetes patient-education programs.
Patient education is generally regarded as an essential component of the clinical management of diabetes. However, analysis of the role of patient education in diabetes control has been limited. Formal patient teaching programs at several medical centers range in operation from merely providing knowledge about diabetes to integrating patient education into the chronic health care system. Improvements in knowledge about diabetes have been demonstrated with patients who have been given questionnaires before and after instruction, but changes in diabetes control and other clinical parameters have not necessarily followed. In those cases in which patient education has been a part of a comprehensive improvement in the entire clinical management of diabetes, significant decreases in rates of hospitalization and acute complications have occurred. Guidelines for future evaluations are discussed.
Southern ethnic food preferences and Exchange values for the diabetic diet.
Explore the source record for details and available documents.
Symposium: Controlling diabetes mellitus with diet therapy.
The effectiveness of caloric restriction and weight reduction in lowering the blood sugar level in obese diabetics has been rediscovered. The twin goals of attaining and maintaining ideal body weight and normoglycemia can be achieved through diet therapy in about 80% of patients who are intensively educated and continuously monitored by a well informed, highly motivated team of physician, dietitian, and nurse. It appears that chronic insulin therapy should be reserved for hyperglycemic individuals who are pregnant or who are at or below ideal body weight, for persons with juvenile onset diabetes who are obviously insulin-dependent, and for acutely decompensated diabetics.
The FDA and hypoglycemic drugs.
Explore the source record for details and available documents.
Adrenal venography and ultrasound in the investigation of the adrenal gland: an analysis of 58 cases.
Adrenal venography has been carried out in 58 patients with the left adrenal vein being successfully catheterized in 91 per cent and the right in 77 per cent. Of the 30 patients with primary hyperaldosteronism, 11 adenomas (12-35 mm diameter) have been demonstrated at venography and two of 15 mm suspected, all of which were confirmed surgically. Aldosterone levels in the adrenal vein plasma were raised on the affected side. In the group of proved micronodular hyperplasia, two patients had surgically confirmed macronodules and venography demonstrated one of 12 mm diameter. Two adenomas of 11 mm and one macronodule of 15 mm have been demonstrated at venography in the remainder who have not had an operation. Ultrasound was carried out in 12 patients with primary hyperaldosteronism, ten of which had tumours at venography. Two adenomas measuring 30 and 31 mm were outlined by ultrasound and confirmed surgically. Seven adenomas, including one macronodule (10-25 mm in diameter) were not defined. Three intra-adrenal phaeochromocytomas (45-90 mm) and one extra-adrenal (80-85 mm) were demonstrated at arteriography, identified by ultrasound and confirmed surgically. Of the ten patients with Cushing's syndrome three had enlarged glands at venography, this was confirmed surgically. Cumulative experience from this analysis and published reports indicate that venography will demonstrate tumours of 10 mm or more in diameter and outline enlarged glands; aldosterone assays will lateralize tumours as small as 3 mm; ultrasound will outline tumours of 30 mm and selective adrenal arteriography will demonstrate tumours of 10 mm. One patient developed acute adrenal cortical insufficiency with intra-adrenal extravasation on one side and thrombosis of the central vein on the opposite side. A second case developed temporary adreno-cortical insufficiency. Published reports indicate that the risk of complication is about 1 per cent. The report includes an anatomical study of the efferent adrenal veins in 50 patients paying particular attention to the diameter, number of accessory hepatic veins, and the angle of entry and position of the right adrenal vein.
Production of chylomicron-like lipoproteins from endogenous lipid by the intestine and liver of diabetic dogs.
Pancreatectomized dogs developed hypertriglyceridemia. This probably resulted from a lack of insulin rather than a lack of glucagon, as it did not develop either in pancreatectomized dogs maintained on insulin, or in dogs with all but the uncinate process of the pancreas removed. The increase in plasma triglycerides was preceded by a decrease in post-heparin lipolytic activity (PHLA) and an increase in FFA. As the hypertriglyceridemia developed in fasted dogs who had previously been on fat-free diets, the triglyceride fatty acids (TGFA) were nondietary. These endogenous TGFA originated from adipose tissue rather than from de novo synthesis. The composition of the lipoprotein TGFA was identical to that of adipose tissue. Furthermore, nicotinic acid blocked the FFA increase and the development of the hypertriglyceridemia. However, it did not prevent the fall of PHLA. Although their TGFA were entirely nondietary, the lipoproteins in these diabetic dogs resembled chylomicrons in their electrophoretic mobility, size, density, and composition. Surgical, histological and tracer studies suggested that in addition to the liver, the intestinal mucosa makes these lipoproteins. The tracer studies also suggested that circulating FFA might enter the intestinal mucosal cells directly and be esterified.
Renin-secreting juxtaglomerular-cell tumour.
Explore the source record for details and available documents.