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Biomedical subjects

C Trevisan

Publications and source records attributed to C Trevisan.

At least 55 records · Page 3Linked to original sources
PubMed1987

Glucose and ketone body turnover in carnitine-palmitoyl-transferase deficiency.

Most of the patients with carnitine-palmitoyl-transferase deficiency (CPT) show reduced levels of blood ketone bodies in the postabsorptive state. In the present study, we have evaluated ketone body and glucose kinetics in patients with CPT deficiency. Intermediate metabolites of carbohydrate and lipid metabolism have also been studied. Ketone body (KB) turnover was measured by means of sequential intravenous bolus injections of 3-14C acetoacetate and 3-14C D(-) 3-hydroxybutyrate in four patients with liver, platelet, and muscle deficiency of CPT system and in eight normal overnight fasting subjects. 6-3H glucose was also injected, along with 3-14C ketone bodies to measure glucose turnover rate. Three out of four CPT deficiency patients had normal KB turnover, despite a marked reduction in liver CPT activity. Only one subject, with severe defect of CPT activity in liver, showed a significantly reduced, but still present rate of de novo synthesis of acetoacetate and 3-hydroxybutyrate (40 and 51 mumol/m-2/min-1 respectively) in comparison with control subjects (103 +/- 14 and 157 +/- 22 mumol/m-2/min-1). Blood concentrations of dicarboxylic adipic and suberic acids were significantly higher in CPT deficiency patients (0.035 +/- 0.007 and 0.021 +/- 0.005, mmol/L respectively) than in control subjects (0.008 +/- 0.008 and 0.006 +/- 0.003 respectively). Basal glucose turnover was increased in CPT deficiency patients (505 +/- 13 mumol/m-2/min-1) in comparison with normal subjects (433 +/- 18 mumol/m-2/min-1; P less than .01) as well as clearance rates (127 +/- 3 mL/m-2/min-1 and 91 +/- 11 mL/m-2/min-1, respectively; P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxybutyric Acid↗
PubMed1987

Clinical varieties of carnitine and carnitine palmitoyltransferase deficiency.

Several clinical entities are associated with disorders of fatty acid oxidation or transfer across the inner mitochondrial membrane. Over 40 cases of the primary carnitine deficiency syndrome have been reported to date and various subtypes have been characterized. This represents a large clinical spectrum. The deficiency of carnitine in muscle is at the basis of a syndrome characterized by muscle weakness and lipid storage myopathy. The systemic form of carnitine deficiency is more generalized and includes recurrent episodes of hepatic encephalopathy as well as lipid storage in muscle, liver and heart. In one subtype, hypoglycemia upon fasting and cardiomyopathy are found. There are also several causes of secondary carnitine deficiency states which are either acquired or associated with inborn errors of metabolism (organic acidurias, defects of acyl-CoA dehydrogenases). Clinically, Carnitine palmitoyltransferase (CPT) deficiency is a rather homogeneous syndrome presenting with recurrent episodes of myoglobinuria provoked by fasting or prolonged exercise. The only exception is an infantile variety associated with severe hypoglycemia and hepatic CPT deficiency. Using malonyl-CoA, a specific inhibitor of CPT-I, we had suggestions in five adult patients with myoglobinuria that CPT-II is lacking in muscle, liver and platelets while CPT-I is above the control level. The enzyme abnormality seems partial and limited to CPT-II or to its binding to the inner mitochondrial membrane.

Acyltransferases↗
PubMed1986

Childhood encephalomyopathy with cytochrome c oxidase deficiency, ataxia, muscle wasting, and mental impairment.

The son of third cousins was normal until age 2 when he had difficulty walking. At age 8 there was limb weakness, ataxia, loss of tendon reflexes, dislalia, and he was mildly retarded. During fasting, urinary organic acid excretion was abnormally high. Cytochrome c oxidase activity in muscle was 7% of the normal mean. The enzyme in platelets was 16% of controls with a decreased cytochrome aa3 peak. These data suggest an autosomal recessive transmission of this variant of cytochrome c oxidase deficiency.

Ataxia↗
PubMed1986

Vitamin D concentrations in women of postmenopausal age with fractures of the femoral neck.

Thirty-eight women of postmenopausal age, suffering from fractures of the femoral neck or vertebral bodies were studied in relation to differences in bone metabolism. The blood and urinary changes concerned in mineral and bone metabolism were recorded within 10 days of trauma, and in some femoral neck fractures, a histological study of the femoral heads removed in the course of prosthetic substitution was carried out. The patients with femoral neck fractures were older than those with vertebral fractures and had metabolic and histological findings suggestive of osteomalacia. A particularly significant difference between the two groups was the plasma level of 25 hydroxycholecalciferol, which was lower in femoral neck fractures, and the urinary excretion of calcium, which was also more reduced in femoral neck fractures. A deficit of vitamin D hepatic metabolite thus appears to be a risk factor for femoral neck fractures in old patients.

Aged↗
PubMed1984

Familial systemic carnitine deficiency.

Two sisters with systemic carnitine deficiency showed the heterogenicity of this condition and a lack of correlation between measurable carnitine levels and clinical manifestations. One child experienced recurrent metabolic encephalopathy, which was diagnosed as Reye's syndrome. The older child, despite lower carnitine concentrations, was asymptomatic. Lipid inclusion myopathy was shown in both children. Serum, muscle, and liver carnitine levels were reduced. The parents had normal serum carnitine concentrations. Both children had significantly abnormal renal handling of carnitine, and their mother, a mild alteration. This family provided evidence for genetic transmission and presumed autosomal recessive inheritance in this disease. Both children were treated with carnitine without clear benefit; no side effects were noted. Previously reported cases of systemic carnitine deficiency were reviewed.

Brain Diseases, Metabolic↗
PubMed1983

Urinary excretion of Iopamidol following intrathecal administration.

No iodinated compound other than Iopamidol was found in the urine of subjects who received intrathecal injection of 10 ml of Iopamiro "300". The compound was neither metabolized nor altered in its optical configuration and urinary iodide content was always in the normal range. Between 72 and 85% of injected Iopamidol was excreted within 72 h of injection.

Biotransformation↗
PubMed1983

Activation of free fatty acids in subcellular fractions of human skeletal muscle.

In human pathology little is known about the activating enzymes for fatty acids of different carbon chain length. In order to have a better insight into disorders of lipid metabolism in human skeletal muscle, we studied the distribution of acyl-CoA synthetases in muscular subcellular fractions. We find that in muscle mainly long chain fatty acids are activated to CoA esters. Distribution of palmityl-CoA synthetase in subcellular fractions compared with marker enzymes suggested that this enzymatic activity is located only in the outer mitochondrial membrane, in contrast to human liver, where this enzyme is also located in the microsomes. In human skeletal muscle we also found low butyryl-CoA formation, which was limited to the mitochondrial matrix. This site of activation implies that short chain fatty acids may not depend on carnitine for their oxidation in the mitochondrial matrix, in contrast to long chain fatty acids activated in the outer mitochondrial membrane.

Coenzyme A Ligases↗
PubMed1983

The Prader-Willi syndrome: neuroendocrine study of identical twins.

Identical twins with the Prader-Willi syndrome are reported. Apart from hypogonadism, hypomentia, hypotonia and obesity, they presented shorter than normal stature and the peculiar facies of this syndrome. Both twins also suffered from arterial hypertension with secondary hyperaldosteronism, an abnormality never previously recorded. The endocrinological study showed the presence of hypogonadotrophic hypogonadism in both twins. The GnRH and clomiphene tests suggested a hypothalamic disorder. Although the vast majority of cases with the Prader-Willi syndrome are isolated, the expression of this disorder in two identical twins enhances the possibility of a genetic determination.

Adolescent↗
PubMed1980

Carnitine palmityl transferase deficiency: myoglobinuria and respiratory failure.

A 51-year-old man presented with acute respiratory failure and myoglobinuria precipitated by an infection. Carnitine palmityltransferase (CPT) deficiency was documented in muscle, leukocytes, and liver. The enzyme defect in liver, previously suspected and now documented, explained the decreased production of ketone bodies during fasting observed in this patient as well as others with muscle CPT deficiency. Decreased utilization of long-chain fatty acids and decreased availability of ketone bodies can deprive the muscle of crucial sources of energy and, in certain conditions, may precipitate myoglobinuria.

Acyltransferases↗