Echocardiographic detection of cardiac involvement in uraemia.
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Biomedical subjects
Publications and source records attributed to B H Robinson.
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A female child presented at one year of age with a febrile illness and loose stools, then developed severe ketoacidosis with vomiting; an apparent salicylate level of 11 mg/dl was measured. A sibling had died in similar circumstances nine years earlier. Investigation revealed that the child did not have salicylate intoxication, and that high levels of acetoacetate in blood and urine were giving readings indicative of the presence of salicylate on routine testing. Gas-liquid chromatographic analysis combined with mass spectrometry on urine samples revealed the presence of 2-methyl-acetoacetate, 2-methyl-3-hydroxybutyrate, and tiglyl glycine in appreciable amounts, indicating a defect in isoleucine catabolism located at the beta-ketothiolase step. The oxidation of 14C-isoleucine to CO2 in cultured fibroblasts confirmed that this pathway was defective. We present evidence that beta-ketothiolase deficiency is not simply a defect of isoleucine degradation; the deficient enzyme is the K+ dependent short-chain mitochondrial thiolase, which also plays a major catalytic role in ketone body and fatty acid oxidation.
29 patients receiving haemodialysis treatment for chronic renal failure were divided into two groups on the basis of the presence or absence of bone disease as defined by radiology and bone alkaline phosphatase. The group of patient with bone disease showed a significantly greater increase in protein-bound calcium during dialysis compared with the control group. There were no significant differences in the changes in total calcium, albumin or hydrogen ion concentration during dialysis between each group. The data suggest that there is a relationship between the increase in protein-bound calcium during dialysis and the incidence of bone disease.
Three children with defective gluconeogenesis and hypoglycemia were treated with frequent daytime feeding and continuous intragastric infusion of glucose at night. By this technique, the blood glucose level was maintained at or slightly above the physiological range. Secondary lacticacidemia, hyperlipidemia, hyperuricacidemia, and coagulation defects all improved. Weight and height velocity increased dramatically. Strength and sense of well-being improved. Nocturnal intragastric infusion of glucose is now the management of choice for children with defective gluconeogenesis and hypoglycemia.
In a case of dihydrolipoyl dehydrogenase deficiency, there was not only an elevation of lactate and alpha-ketoglutarate but also of branched chain amino acids. The levels of branched-chain amino acids varied from the normal range to three times the upper limit of normal during the patient's lifetime, and alloisoleucine was detectable at all times. Examination of postmortem tissues revealed that the activity of branched-chain keto acid dehydrogenases was between zero and 10% of that in control tissues. It is suggested that the multiple defects seen in oxidative decarboxylation in this patient is the consequence of a single genetic deletion of an enzyme common to pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase, and branched chain keto acid dehydrogenases.
The activities of five mitochondrial enzymes tested in liver from patients with Reye's syndrome were measured. Citrate synthase, glutamic dehydrogenase, succinic dehydrogenase, pyruvate carboxylase, and pyruvate dehydrogenase were all outside of the range shown by control samples and well below them in activity. The activity of two extramitochondrial enzymes, glucose-6-phosphatase, which is a microsomal enzyme, and fructose-1,6-diphosphatase, which is a soluble enzyme, were in the normal range in samples from Reye's syndrome patients. In both muscle and brain the activities of the mitochondrial enzyme, citrate synthase, glutamic dehydrogenase, and succinic dehydrogenase were all within the control range. Pyruvate dehydrogenase was found to be normal in muscle from these patients.
A double blind cross-over trial of Nandrolone decanoate (Decadurabolin) was carried out in 27 patients with anaemia due to end stage renal disease, stabilised on regular haemodialysis. Sixteen patients completed the study, the other patients being excluded from the final analysis for a variety of reasons including side effects related to the androgen. There was no sustained significant rise in haemoglobin concentration or in red cell mass. Erythropoietin levels did not alter, they were within or below the normal range, but were lower than would be expected for the degree of anaemia. A majority of patients reported increased well-being including exercise tolerance, appetite and libido. Voice changes and hirsutism were noted, mainly in the females. Instability of anticoagulant therapy and abnormalities in liver function were found in some patients. The benefits, though real, were restricted essentially to the improvement in subjective findings and were unrelated to laboratory measurements. These effects might be obtained with a lower dosage of the drug.
In a review of 250 consecutive human cadaveric kidney transplants the primary failure rate of donor kidneys with an anatomically abnormal blood supply was 36.7% as compared with 16.2% for kidneys with a single artery and vein (P less than 0.001). The incidence of primary failure due to renal vascular thrombosis in the abnormal group was 24.2%, compared with 4.1% in the normal group (P greater than 0.001). A significantly greater incidence of anastomotic haemorrhage and urinary leak was also associated with an abnormal blood supply in the donor kidney.
1. Bicarbonate increased citrate and 2-oxoglutarate accumulation when rat kidney cortex mitochondria were incubated with pyruvate or L(-)-palmitoyl carnitine in the presence of L-malate. 2. Bicarbonate stimulated the exit of citrate from mitochondria. The Km for bicarbonate was 13.5 mM and the Vmax was 0.59 nmol/min/mg of protein at 10 degrees. 3. The bicarbonate-stimulated exit of citrate from the mitochondria was prevented by inhibitors of the tricarboxylate, dicarboxylate, and phosphate transport systems. 4. The activity of pyruvate dehydrogenase was significantly increased by preincubation of rat kidney mitochondria with bicarbonate. This bicarbonate-induced activation was not observed in presence of inhibitors of citrate transport. Bicarbonate did not activate pyruvate dehydrogenase in rat heart mitochondria. Bicarbonate had no effect on pyruvate dehydrogenase activity in either broken mitochondria or whole tissue preparations. 5. The mechanism of this activation is discussed in the light of the known regulatory properties of pyruvate dehydrogenase, pyruvate carboxylase, and citrate synthase.
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In vivo neutron activation analysis was used to measure changes in whole body calcium in patients with chronic renal failure. Eight patients, not treated by haemodialysis, showed losses of calcium in contrast to increases noted in twenty-one patients treated by haemodialysis. Changes in whole body calcium were independent of pre-existing renal bone disease. Treatment of bone disease by total parathyroidectomy (six patients) or 1alpha-hydroxyvitamin D3 (eleven patients) resulted in large increases in total body calcium. In patients given 1alpha-hydroxyvitamin D3, changes in total body calcium correlated with histological and radiological indices of response but variable changes in forearm bone mineral content were observed. Neutron activation analysis provides a convenient method for measuring skeletal mass and may also be useful in the assessment of response to 1alpha-hydroxyvitamin D3 of patients with osteitis fibrosa and osteomalacia.
During treatment of renal osteodystrophy with 1alpha-hydroxyvitamin D3 in eleven patients, regional changes in the skeleton have been compared with long-term calcium balance as assessed by whole-body calcium. Radial bone changes did not correlated well with calcium balance, but spinal calcium changes were of a similar magnitude when changes were large. Bone alkaline phosphatase changes correlated well with changes in spinal calcium, but less well with changes in radial bone density.
The development of total pyruvate dehydrogenase activity in the subhuman primate, Macaca mulatta, was investigated in brain, liver, kidney cortex, and skeletal and cardiac muscle. Newborn primates delivered prematurely at 135 days of gestation had only 32% of this enzyme activity present in the brain compared to the full-term animal. Full-term animals were similar to adults. All tissues showed high activities of enzyme at 1 year of age compared either with neonates or adults. Kidney cortex showed an increase in activity from 807 +/- 74 mumol/g/min in prematurely delivered neonates to a maximum of 3,769 +/- 275 mumol/g/min in 1-year-old animals. The results are discussed in relation to the developing energy requirements of the tissues concerned.
The activity of certain hepatic enzymes involved in carbohydrate metabolism was measured in postmortem samples from six cases of Reye's syndrome. The activities of the two exclusively extramitochondrial enzymes, glucose-6-phosphatase and fructose-1,6-diphosphatase, were all within the normal range. Activities of pyruvate carboxylase and pyruvate dehydrogenase, both of which are exclusively mitochondrial enzymes, were below levels, shown by control tissue in every case, the average being 21.7% of the lowest control value for pyruvate carboxylase and 11.6% of that for pyruvate dehydrogenase. Impaired pyruvate metabolism appears to be another feature in Reye's syndrome.
A male child died at 7 months of age with progressive neurologic deterioration and persistent metabolic acidosis. Investigations during life showed this child to have elevated blood pyruvate, lactate, and alpha-ketoglutarate as well as elevation of branched chain amino acids and occasional hypoglycemia. Cofactor therapy using either thiamine-HCl (2 g/kg/24 hr) or thiamine tetrahydrofurfuryl disulfide had no measurable effect on the clinical or biochemical status of the patient. Tissue taken postmortem showed normal levels of key gluconeogenic enzymes but a deficiency in the activity of pyruvate dehydrogenase in all tissues tested (liver, brain, kidney, skeletal muscle, and heart). Examination of the individual activities of pyruvate dehydrogenase complex showed pyruvate decarboxylase (E1) to be normal in liver and other tissues. Dihydrolipoyl dehydrogenase (E3), on the other hand, was deficient in all tissues tested. alpha-Ketoglutarate dehydrogenase complex, which depends of E3 for its total activity, was also deficient in all tissues tested. The absence of this enzyme id discussed in relation to the clinical and biochemical status of the patient.
Ten patients with renal bone disease have been treated with 1 alpha-hydroxycholecalciferol for periods of 10-18 months. Responses in bone histology, plasma alkaline phosphatase, whole body calcium, spinal calcium content and bone mineral content of the forearm were compared. Improvements in histology of bone were seen in 5 patients. These patients showed greater increases in total body calcium, and the increments in total body calcium correlated significantly with decrements in alkaline phosphatase. Changes in forearm bone mineral content or spinal calcium were less predictable and did not invariably reflect measured changes in whole body calcium. We conclude that total body calcium may provide a useful and early index of response to treatment with 1 alpha-hydroxycholecalciferol. In contrast, skeletal changes noted by regional methods of assessment should not be judged as reflecting changes occurring in the whole skeleton, and may even be misleading.
Four selected adults with different patterns of osteodystrophy receiving regular dialysis were treated with 1-alpha-hydroxycholecalciferol (1-alpha-OHD3) 0-5-2 mug/day for 10 to 12 months. In two patients, one with osteitis fibrosa and the other with osteomalacia, significant biochemical, radiological, and histological improvements occurred, and total body calcium measured by in-vivo neutron activation analysis increased. In two patients, in whom there were no increases of whole-body calcium, neither biochemical improvement nor healing of bone lesions occurred during the study; in one of these patients the effect of 1-alpha-OHD3 on bone resorption may have contributed to loss of body calcium and deterioration of bone disease. 1-alpha-OHD3 may therefore be a valuable adjunct in the treatment of only some patients with renal osteodystrophy. Whole-body in-vivo neutron activation seems to provide a sensitive and non-invasive index of early response to treatment.