Altered tissue carnitine levels in animals with hereditary muscular dystrophy

Low levels of muscle carnitine have been found in patients with Duchenne dystrophy, a case possibly of Becker dystrophy, and limb-girdle syndrome as well as in patients with the recently described muscle carnitine deficiency syndrome. Tissues of the mouse, hamster, and chicken were analyzed to determine whether tissue carnitine levels were altered in the animal models of muscular dystrophy. Significantly higher levels of carnitine were found in dystrophic mouse muscle, but carnitine levels in plasma, liver and heart were normal. Histological changes in the skeletal muscle of dystrophic hamsters were relatively mild, and both skeletal muscle and plasma levels were normal. The liver carnitine level was higher than normal levels. The dystrophic hamster also had an inherited cardiomyopathy, and interestingly its heart carnitine level was much lower than normal. The red muscle of the normal chicken contained 5 times the level of carnitine found in white muscle. The dystrophic chicken had higher than normal levels of carnitine in the white muscle, but normal levels in the red muscle. Although all 3 animal models of muscular dystrophy studied have altered levels of carnitine in some tissue, none of the animal models had the same pattern of altered tissue carnitine levels seen in human patients.

Erythrocyte membrane abnormalities in Duchenne muscular dystrophy monitored by saturation transfer electron paramagnetic resonance spectroscopy

Saturation transfer electron paramagnetic resonance and the spin label 2-(3-carboxypropyl)-4,4-dimethyl-2-tridecyl-3-oxazolidinyloxyl were used to study erythrocytes from patients with Duchenne muscular dystrophy or Becker syndrome and from age-matched normal boys. There were significant differences in the spectral intensities of erythrocytes from Duchenne patients when compared to controls. Spectral intensities increased with time in the former; no such change was observed in the latter. Saturation transfer electron paramagnetic resonance spectra of erythrocytes from patients with Becker syndrome were significantly different from those from Duchenne patients but were not significantly different from normals. These observations suggest the possible usefulness of these techniques in the differential diagnosis of Duchenne muscular dystrophy. Spin label concentration spectral studies suggest that the observed spectral differences between Duchenne patients and controls were due to differential spin exchange phenomena.

Global monitoring of stratospheric halogen compounds from a satellite using gas filter spectroscopy in the solar occultation mode

We have analyzed the gas filter radiometer approach for long-term monitoring of stratospheric HCl, HF, CH(4), and H2O using solar occultation at selected intervals in the 2-6 microm range. Our analysis shows that this instrument technique is feasible. This conclusion is based on a simulation study in which we evaluated the effect of various experiment errors on retrieval accuracy. The instrument errors used were based on measurements made on a breadboard model gas filter radiometer. The results show that HCl and HF can be measured with an rms error of 10% and CH(4), and H2O with an error of 15% over the 10-30-km range.

Penicillamine treatment of hereditary avian muscular dystrophy

Images

Enzymological studies on hereditary avian muscular dystrophy

White and red muscles of normal and genetically dystrophic chickens were compared with regards to activity levels of three soluble enzymes, glyceraldehyde-3-phosphate dehydrogenase, creatine phosphokinase, and acetyl phosphatase. In dystrophic white muscle (pectoral), activity of the two sulfhydryl enzymes, glyceraldehyde-3-phosphate dehydrogenase and creatine phosphokinase, was preferentially lost from the sarcoplasm resulting in decreased specific activities. By contrast, acetyl phosphatase was preferentially retained and showed increased specific activity. Dystrophic white muscle had decreased sulfhydryl content in the soluble proteins, severe reduction in muscle mass, fatty infiltration, and fragmentation of fibers. Red dystrophic muscles (thigh) were minimally involved in accordance with the known sparing of red fibers. Enzyme activities were correlated with histological observations. The results suggested that the disease process in dystrophic white muscle may be related to alterations in the sulfhydryl groups of proteins. The data are correlated with the beneficial effects of our treatment of hereditary avian dystrophy with the sulfhydryl compound, penicillamine (Chou, T.H., Hill, E.J., Bartle, E., Woolley, K., LeQuire, V., Olson, W., Roelofs, R., and Park, J.H. (1975) J. Clin. Invest. 56, 842-849).

Cysticercosis in otolaryngology

Cysticercosis is not likely to be the first diagnosis the otologist has in mind when regarding tumors in the head and neck area. The fact that this disease may present a diagnostic and therapeutic problem is illustrated by three cases, appearing in the tongue, buccal mucosa, and midline of the neck, respectively. The local finding of a soft nontender mass, the typical calcifications in the soft tissues visible on roentgenograms, and the histopathological findings are described and illustrated. Attention is drawn to the fact that cerebral cysticercosis, which is a very grave disease, may cause tinnitus, nystagmus, and hearing disturbances.

Beneficial effects of penicillamine treatment on hereditary avian muscular dystrophy

Hereditary muscular dystrophy in chickens of the New Hampshire strain was treated with penicillamine from the 9th day after hatching to the 425th day. The adult maintenance dose for males was 50 mg/kg per day and for females, 13-65 mg/kg per day. In avian dystrophy, deterioration of the muscle fibers is evidenced in the 2nd mo by an inability of the birds to rise after falling on their backs and by a progressive rigidity of the wings. The drug delayed the onset of symptoms and partially alleviated the debilitating aspects of the disease. Penicillamine produced three major improvements: (a) better righting ability when birds were placed on their backs; (b) greater wing flexibility; (c) and suppression of plasma creatine phosphokinase activity. The results are statistically analyzed and discussed in relationship to Duchenne dystrophy. Normal birds were not affected by penicillamine as judged by these parameters. The rationale for using penicillamine, a sulfhydryl compound with reducing properties, was (a) to attempt to protect essential thiol enzymes in the anabolic and glycolytic pathways against inactivation and (b) to prevent collagen cross-linking and deposition in muscle. Although the precise mechanism of drug action has not been determined. the possible role of penicillamine in mitigating the symptoms of genetic dystrophy in man is under consideration. Further, penicillamine may have a more generalized application i the prevention of contractures in a variety of neuromuscular disorders.

Covalent binding of 3-pyridinealdehyde nicotinamide adenine dinucleotide and substrate to glyceraldehyde 3-phosphate dehydrogenase

Glyceraldehyde 3-phosphate dehydrogenase (D-glyceraldehyde-3-phoshate:nicotinamide adenine dinucleotide oxidoreductase (phosphorylating), EC 1.2.1.12) forms a complex with 3-pyridinealdehyde-NAD which survives precipitation with 7% perchloric acid. The molar ratio bound 3-pyridinealdehyde-NAD to the enzyme is 2.5 to 2.9. Lactate, malate, and alcohol dehydrogenases do not form acid-precipitable complexes with 3-pyridinealdehyde-NAD. 3-Pyridinealdehyde-deamino-NAD or glyceraldehyde 3-phosphate also forms an acid-stable complex with glyceraldehyde 3-phosphate dehydrogenase; however, NAD, 3-acetylpyridine-NAD, or thionicotinamide-NAD does not produce an acid-stable complex. Incubation of the glyceraldehyde 3-phosphate dehydrogenase with glyceraldehyde 3-phosphate, acetyl phosphate, iodoacetic acid, or iodosobenzoate inhibits the formation of the acid-stable complex with 3-pyridinealdehyde-NAD. Glyceraldehyde 3-phosphate or 3-pyridinealdehyde-NAD also prevents carboxymethylation of the active site cysteine-149 by[14-C]iodoacetic acid. These studies indicate that the aldehyde group of 3-pyridinealdehyde-NAD forms a thiohemiacetal linkage with cysteine-149 which is the substrate binding site for the dehydrogenase reaction. These findings may account for the fact that 3-pyridinealdehyde-NAD strongly inhibits the dehydrogenase and esterase activities of 3-pyridinealdehyde-NAD forms a thiohemiacetal linkage with cysteine-149 which is the substrate binding site for the dehydrogenase reaction. These findings may account for the fact that 3-pyridinealdehyde-NAD strongly inhibits the dehydrogenase and esterase activities of glyceraldehyde 3-phosphate dehydrogenase which require reduced cysteine-149. However, the analogue does not inhibit the acetyl phosphates activity of the enzyme for which the active site sulfhydryl residues must be oxidized.

Herpetic keratoconjunctivitis: therapy with synthetic double-stranded RNA

A study was undertaken in rabbits to determine how late in the course of keratoconjunctivitis caused by herpes simplex recovery could be effected by an inducer of interferon. Interferon was induced by means of synthetic double-stranded RNA copolymer formed with polynosinic acid: polycytidilic acid RNA. Therapy promotes recovery from severe and fully established keratoconjunctivitis for which treatment was begun as late as 3 days after virus inoculation. No drug toxicity was observed in the therapeutic dose range. These findings further support the proposed role of the interferon mechanism in the natural recovery of already established viral infection. They also suggest the usefulness of interferon inducers in viral infections of man.