Search PubMed⌕ Search

Biomedical subjects

J E Carroll

Publications and source records attributed to J E Carroll.

At least 73 records · Page 4Linked to original sources
PubMed1980

Carnitine "deficiency": lack of response to carnitine therapy.

A 29-year-old women had muscle weakness, low concentrations of carnitine in muscle and serum, and abnormally low urinary excretion of carnitine. During a fast, exercise capacity declined, ketone body concentrations rose, metabolic acidosis worsened, and she became hypoglycemic. After treatment with oral carnitine, serum carnitine content returned to normal and blood glucose was maintained during fasting, but ketone body concentrations in blood were even higher. Muscle carnitine content and exercise capacity did not improve. This patient demonstrated features of both systemic and muscle carnitine deficiency, suggesting that the current classification of carnitine-deficiency syndromes is inadequate.

Adolescent↗
PubMed1979

Bicycle ergometry and gas exchange measurements in neuromuscular diseases.

Using bicycle ergometry with computerized respiratory gas exchange measurements, we compared exercise capacities in patients with various neuromuscular diseases to those in normal controls. As expected, male and female patients had significantly reduced maximum work capacities (kilopond-meters per minute per kilogram of body weight) and maximal oxygen consumptions. The oxygen cost of exercise was normal in the majority of patients, although some appeared to have abnormally high oxygen consumptions during exercise. Breathing patterns during exercise, particularly in regard to onset of hyperventilation, were similar in patients and controls.

Adolescent↗
PubMed1979

Fasting as a provocative test in neuromuscular diseases.

A 38-hr fast was used as a provocative test in patients suspected of having defects in muscle substrate utilization. In five controls and nine patients, exercise capacity and respiratory exchange ratio were determined before and at the end of the fast. Blood was collected at intervals during the fast from ten controls and nine patients for creatine kinase (CK), free fatty acids, (FFA) beta-hydroxybutyrate, acetoacetate, free and total carnitine, glucose, and alanine. Two patients with myophosphorylase deficiency had increased exercise capacity, and a marked fall in CK, and one had a lesser fall in blood glucose than normal at the end of the fast. Two patients with known lipid myopathies (carnitine deficiency and carnitine palmityl transferase deficiency) had decreased exercise capacity and apparent increased dependence on carbohydrate metabolism during the fast. Carnitine concentrations became even more abnormal in the patient with carnitine deficiency during fasting. Several patients with less well-defined defects were also significantly different from the controls in several respects, indicating that the fast might be useful for finding new defects.

Adult↗
PubMed1979

The prolonged exercise test.

The response to a standardized exercise test was investigated in 12 volunteers and 13 patients with aches, cramps, and pains. In men, creatine kinase (CK) levels peaked (up to 1600 mU per milliliter) between 10 and 20 hours after exercise. High levels of blood lactate during exercise were related to the intensity of work and to high levels of CK after exercise. The patients could be divided into several groups: (1) those with no change in blood metabolites (psychogenic); (2) those with a disproportionate rise in CK (metabolic myopathies); (3) those with a disproportionate rise of lactate (mitochondrial abnormalities); and (4) in one patient with exercise-related pains, subnormal elevation of fatty acid levels. The correlation of changes in blood lactate, CK, and fatty acids may be useful, whereas an isolated measurement, even if outside the normal range, is often meaningless.

Adult↗
PubMed1979

Increased serum creatine kinase after exercise: a sex-linked phenomenon.

The effect of 2 hours of exercise on the serum creatine kinase (CK) level was investigated in 11 men and 9 women. The mean increase of CK 24 hours after exercise was significantly greater in men. The relative lack of CK elevation in women may: (1) indicate that female muscle is less susceptible to damage by adverse factors; and (2) explain discrepancies in previous reports.

Creatine Kinase↗
PubMed1978

A new congenital neuromuscular disease with trilaminar muscle fibers.

An infant was born with marked rigidity, a paucity of spontaneous movements, and increased serum creatine phosphokinase activity. Electromyogram was normal. A muscle biopsy, taken at the age of 7 weeks, contained numerous fibers composed of three concentric zones, warranting the designation "trilaminar fibers." Electronmicroscopy showed the innermost zone contained a densely packed collection of mitochondria, glycogen, electron opaque material, and single filaments. The middle zone consisted of myofibrils with Z-band smearing. The outer zone resembled a sarcoplasmic mass. Extrajunctional acetylcholine receptor (AChR) was present in the trilaminar fibers between the middle and outer zones. The increased muscle tone and extrajunctional AChR suggest and altered neural influence, but the markedly increased creatine phosphokinase activity is more characteristic of muscle damage. Precise definition of the nature of the defect awaits further study.

Female↗
PubMed1977

The spectrum of mild X-linked recessive muscular dystrophy.

We present 19 patients from 12 families with mild (Becker) X-linked recessive dystrophy and compare them with previously described cases. Features in common in the majority of patients include onset after the age of 7 years, walking beyond the age of 20 to 30 years, mild hypertrophy of the calves, mild joint contractures, and high arched feet. Pshychometric tests, EEGs, and ECGs were usually normal. Muscle biopsy specimens showed a combination of features, some more characteristic of severe (Duchenne) X-linked dystrophy and others more commonly seen in limb girdle dystrophy. Although there was some variation in the severity between different families, within any one kindred, the clinical picture was quite similar.

Adolescent↗
PubMed1977

Guillain-Barré syndrome. Another cause of the "floppy infant".

We report a 4 1/2-month-old female infant with subacute onset of hypotonia. Symmetrical weakness, association with a viral illness, high CSF protein level, diminished nerve conduction velocities, and a prompt recovery were compatible with the diagnosis of Guillain-Barré syndrome. The possibility that this disorder may occur in young infants with weakness should be considered.

Female↗
PubMed1977

Blood flow and uptake of glucose and amino acids in ischemic muscle.

In order to examine muscle ischemia, muscle blood flow in the rat hindlimb was decreased by vessel ligation. Amino acid uptake, studied with [14C]alpha-aminoisobutyric acid, was decreased in ischemic Type I (soleus) muscle. Glucose uptake, studied with [14C]deoxyglucose, was increased in Type I muscle. These changes were temporally associated with histologic changes of ischemia in soleus muscle. Denervation, atrophy, and hypertrophy also produced uptake changes with these techniques, and although more prominent in soleus, the changes were also seen in Type II muscle.

Absorption↗
PubMed1977

Ventilatory response in myotonic dystrophy.

Patients with myotonic dystrophy often develop respiratory failure caused by alveolar hypoventilation. Abnormalities in the ventilatory response to hypoxia and hypercapnia may explain this phenomenon. Accordingly, hypoxic and hypercapnic responses were measured in seven patients with myotonic dystrophy who had only mild respiratory muscle weakness. Hypoxic response was significantly reduced, while hypercapnic response was affected more irregularly. It is possible that the high incidence of respiratory failure in such patients is related to decreased hypoxic ventilatory response, occurring because of an underlying neurogenic deficit.

Adult↗
PubMed1976

Inflammatory myopathy, IgA deficiency, and intestinal malabsorption.

Two IgA-deficient children with inflammatory myopathy and intestinal malabsorption were evaluated. The myopathy was characterized by weakness of facial and proximal limb muscles, increased serum concentrations of lactic dehydrogenase and creatine phosphokinase, and histologic evidence of inflammation and degeneration of muscle fibers. Features of the intestinal abnormality were blunted villi, interstitial inflammation, and reduction in IgA-containing plasma cells and IgA content of epithelial cells. The myopathy and malabsorption improved with corticosteroid treatment. Circulating antibodies to striated muscle could not be demonstrated in either patient, but one had antibodies to milk and chicken serum proteins. We speculate that IgA deficiency may predispose to the development of inflammatory myopathy.

Autoantibodies↗
PubMed1976

Depressed ventilatory response in oculocraniosomatic neuromuscular disease.

Four patients with ptosis, external ophthalmoplegia, and ragged-red fibers on muscle biopsy were found to have decreased ventilatory responses to hypoxia and hypercapnia. Respiratory muscle weakness was not responsible for these findings since these responses were normal in muscle disease control patients. An altered metabolic state also can cause diminished ventilatory response, but overall oxygen consumption data in the ragged-red fiber patients were normal. The decreased ventilatory responses may be clinically significant because two of the ragged-red fiber patients had episodes suspicious of hypoventilation with poor response to hypoxia.

Adolescent↗
PubMed1975

A simple, inexpensive, high pressure liquid chromatographic method for separating cytokinins in plant extracts.

Separation of a mixture of the main cytokinins occurring naturally in plant tissues was achieved by high pressure liquid chromatography using insoluble polyvinylpyrrolidone as the solid support. The separation of each cytokinin was first assessed over a range of salt and l-butanol concentrations and pH using a mixture of borate buffer and l-butanol as the mobile phase to determine the conditions necessary for optimum resolution. A discrete separation of zeatin, N-6-(Delta-2-isopentenyl)adenine, their related ribonucleosides, and kinetin was achieved using a simple isocratic elution with 0.025 m borate buffer at pH 6.8 and 4% (v/v) l-butanol. A number of cytokinin-active compounds were detected in cabbage extracts by the Amaranthus betacyanin bioassay using this separation technique.

Journal Article↗