Purple membrane was reacted with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide at pH 4.5 and 8.0. At pH 4.5, the reaction yields cross-linked bacteriorhodopsin. The cross-linking is inhibited by pretreatment of the membrane with papain, or by the presence of carbohydrazide or glycine ethyl ester in the reaction mixture. The product of the pH 8.0 reaction is not cross-linked, but it displays altered properties. Two measures of photochemical activity (light-induced change in proton binding (delta h) and decay of photointermediate M) show changes indicative of slowed proton uptake. The delta h is increased by ethyl dimethylaminopropylcarbodiimide. This increase is unaffected by pretreatment of the membrane with papain, and it is not reversed by NH2OH. However, the reaction is inhibited by millimolar concentrations of CaCl2. The altered delta h is not apparent in detergent-solubilized membranes. Ethyl dimethylaminopropylcarbodiimide does not appear to cause a large alteration in the membrane surface charge, as measured by Ca2+ binding. We conclude that (1) at acid pH, ethyl dimethylaminopropylcarbodiimide can be used for cross-linking or for attachment of specific probes to the C-terminal region of bacteriorhodopsin, and hence to the cytoplasmic side of the purple membrane, and (2) at alkaline pH, ethyl dimethylaminopropylcarbodiimide reacts at a diffent type of site and appears to inhibit the proton pump.

Bacteriorhodopsins↗

PubMed1979

Angle closure in carotid-cavernous fistula.

The case reported is one of the angle closure and pupillary block associated with carotid-cavernous fistula. Pathophysiologic mechanisms, involving elevated orbital venous pressure, are explored.

Aged↗

PubMed1979

Cavernous hemangioma of the orbit.

The clinical and pathological data of 66 patients with orbital cavernous hemangioma are presented. This tumor occurs in females more frequently than in males, and has its peak incidence in early middle age. Visual disability results from a high degree of relative hyperopia or from optic-nerve compression. Postural or temporal variation is proptosis is not characteristic. Multiple cavernous hemangiomas are rare, but may occur simultaneously or separated by long intervals. In this series, incompletely excised lesions did not cause recurrent proptosis. Relative hyperopia may persist, in spite of complete removal of the tumor. Improved preoperative localization with modern techniques appears to be reducing the morbidity associated with surgical excision of the lesion. A local hemodynamic disturbance may initiate proliferation of vascular channels that undergo progressive ectasia. Growth of the lesion may occur intrinsically by the budding-off of capillary channels from cavernous spaces into the interstitium. Clinical and pathological findings fail to demonstrate any relationship between this lesion and capillary hemangioma of childhood.

Adolescent↗

PubMed1979

Cat optic nerve imaging with metrizamide.

Metrizamide is a water-soluble, nonionic radiocontrast medium that penetrates better into narrow subarachnoid spaces than do oily contrast media or gas. We performed metrizamide optic nerve thecography on five cats with iatrogenic orbital lesions. Optic thecograms successfully demonstrated displacement of the optic nerve, obstruction of the optic nerve sheath subarachnoid space, and extravasation of the contrast medium from a punctured optic nerve sheath. Metrizamide-induced seizures could be prevented by intramuscular preadministration of diazepam.

Animals↗

PubMed1978

Orbital hematoma secondary to frontal sinusitis.

A 30-year-old woman had an orbital hematoma with frontal sinusitis. This complication of infection in the paranasal sinuses has not been previously described, but is explainable in anatomic terms. On computed tomographic scanning, the degree of enhancement with contrast infusion was striking and may aid in future diagnosis of this condition.

Adult↗

PubMed1977

Growth and development of gastrocnemius muscle in S 5B/PL and Osborne-Mendel rats overfed during nursing.

Three techniques for overfeeding rat pups were used from birth to 24 days of age to assess their effect on growth and development in an obesity susceptible (OM) and an obesity resistant (S 5B/P1) strain of rat. These included: (1) Feeding a semi-purified high fat rather than low fat diet to the dams (alters the energy content of milk); (2) Raising pups in litters of 3 rather than 6; and (3) Force feeding of milk in lieu of any force feeding. In OM rats there was no difference in lean body mass (excludes heart, liver and kidney) (LBM) gastrocnemius muscle weights, cell number and protein content of muscle. Body weights and gastrocnemius muscle triglycerides were significantly higher in OM rats fed the high fat diet than in those fed the low fat diet. S 5B/P1 (S) rats treated in the same manner as OM, showed no significant differences in body weight, LBM, gastrocnemius muscle weight or content of DNA, protein or triglycerides. Protein and DNA for 100 g fresh gastrocnemius muscle were similar for the two strains even though the muscle was 1 1/2 times heavier in OM than in S rats. Muscle triglycerides were higher in OM than in S rats.

Animals↗

PubMed1976

Cyst of the intraorbital optic nerve sheaths.

A 43-year-old woman had a history of gradual unilateral visual acuity loss and proptosis. A 2.5-cm cystic dilatation of the intraorbital dura mater was removed. Microscopic examination revealed a vascular proliferation within the leptomeninges. We inadvertently injected the lesion during orbitography, providing us with an unusual radiographic appearance.

Cysts↗

PubMed1974