Myotube-like structures were seen in extraocular and limb muscles in an adult with centronuclear myopathy. The limb-muscle fibers were very small and were of a uniform histochemical type. Extrajunctional acetylcholine receptors were not seen with immunoperoxidase stains, and ultrastructurally normal neuromuscular junctions were seen in the extraocular-muscle samples. Further studies on developing muscle are needed to identify possible mechanisms of arrest of muscle maturation.

Adenosine Triphosphatases↗

PubMedDate not supplied

Meningiomas of the anterior visual system.

Meningiomas, whether primary in the orbit, optic canal or intracranial area, typically cause slowly progressive loss of vision covering months to years. They usually occur in white women of middle age. Tumors in the orbit or optic canal almost always affect vision unilaterally; intracranial tumors, while usually causing unilateral visual loss initially, eventually cause bilateral loss of vision, often with blindness in one eye. Depending upon the size and location of the tumor, the ocular signs and symptoms of meningiomas may include visual field abnormalities, optic atrophy, edema of the ipsilateral optic disc, papilledema, diplopia, and proptosis. The diagnosis of meningiomas in all locations has been greatly facilitated by recent advances in computer assisted tomography. However, tumors confined to the optic canal or its foramina are small when vision is first lost and therefore are still difficult to detect. Hypocycloidal polytomography may be useful; other neuroradiologic studies rarely are. Treatment is surgical. Based on a review of more than 3000 meningiomas reported in the literature, the frequency and characteristics of the signs and symptoms of meningiomas in each location are discussed, as are the anatomy, pathology, natural history, and probable mechanisms.

Adolescent↗

PubMedDate not supplied

The evaluation of a clinical thermometer for measuring developer temperature in automatic film processors.

In medical imaging, the temperature of the developer solution in the film processor affects film speed (radiation dose), film contrast, and film base plus fog. The National Council on Radiation Protection and Measurement (NCRP) Report 99 on Quality Assurance, and the American College of Radiology (ACR) Mammography Quality Control Manual for Radiologic Technologists, indicate that the developer temperature should be within +/- 0.5 degree F (+/- 0.3 degree C) of that recommended by the manufacturer for the specific film/developer combination being used. The accuracy and repeatability of the thermometer is most important. This paper describes the requirements of a thermometer for measuring the temperature of the developer solution and suggests an inexpensive but accurate device for doing so.

Evaluation Studies as Topic↗