Gadolinium-DTPA-enhanced magnetic resonance imaging in experimental optic neuritis.

Magnetic resonance imaging (MRI) with gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) was used to investigate disruption of the blood-optic nerve barrier associated with acute autoimmune demyelination. Leakage of Gd-DTPA was seen in the optic nerves and optic chiasm of adult guinea pigs sensitized for acute experimental allergic encephalomyelitis, but not in normal unsensitized animals. This finding occurred as early as 5 to 8 days after antigenic sensitization with the myelin emulsion and before the onset of paralysis or ataxia.

Gadolinium-DTPA-enhanced magnetic resonance imaging in optic neuropathies.

Magnetic resonance imaging (MRI), after intravenous administration of the paramagnetic agent gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA), showed enhancement of the optic nerve in 7 of 13 patients with acute optic neuritis. Four of these patients had Gd-DTPA enhancement of the intracranial optic nerve and two had involvement of the optic nerve at the orbital apex, ipsilateral to the eye with visual loss. Gadolinium-DTPA enhancement of both intracranial optic nerves was seen in one of two patients with bilateral retrobulbar neuritis.

Reactivation of latent pseudorabies virus infection in vaccinated commercial sows.

Pseudorabies virus (PRV) was isolated from 9 of 44 PRV-vaccinated seropositive sows on 5 of 11 farms. Although serum-neutralization antibody titers were 1:16 to 1:256, 28 virus isolates were obtained from tonsil, nasal, or buccal swab samples from 9 sows given 2 ml of dexamethasone/kg of body weight IM for 5 days. Pseudorabies virus was isolated from 6 of 20 sows (3 of 5 farms) given a killed-virus vaccination.

Phase II evaluation of mitoxantrone in advanced pancreatic carcinoma: a Southwest Oncology Group study.

Patient with advanced adenocarcinoma of the pancreas and no prior chemotherapy were treated on a Phase II trial of mitoxantrone. Doses were adjusted for hepatic dysfunction as defined by bilirubin. Twenty-four patients with a bilirubin less than or equal to 1.

Treatment of visual loss in pseudotumor cerebri associated with uremia.

Ten patients with pseudotumor cerebri associated with renal insufficiency had papilledema and elevated intracranial pressure, but neurologic examinations and CT were normal. The 40% frequency of severe visual loss, 20/100 or worse, was higher than expected for pseudotumor cerebri. While furosemide was effective in 3 patients with renal transplants, administration of corticosteroids to 2 other patients did not halt progressive loss of vision.

Virulence of infectious laryngotracheitis viruses: comparison of modified-live vaccine viruses and North Carolina field isolates.

Virulence of six modified-live (ML) infectious laryngotracheitis (ILT) vaccine viruses was compared with that of 11 field isolates (indistinguishable from vaccine viruses by DNA restriction endonuclease analyses) by intratracheal exposure of 4-week-old, specific-pathogen-free chickens. Virulence of ILT viruses was based on an intratracheal pathogenicity index, mortality, and tracheal lesions. Intratracheal pathogenicity indices for ML vaccine viruses ranged from 0.

[University by radio and television in Great Britain. The Open University].

There are some 20 years since Great Britain was given a new and important University (established by a Royal Charter in 1969), especially intended for students wanting to achieve their education at home. The whole teaching, guided by tutors, is supported by various materials: booklets, audio- and videotapes which are completed by television and radio broadcasts for many courses and informations. After successful examinations are obtained the usual degrees and certificates delivered by the British Universities.

Spectra of G ratio, myelin sheath thickness, and axon and fiber diameter in the guinea pig optic nerve.

The spectra of fiber and axon diameter, myelin sheath thickness, fiber density, and g ratio of the optic nerve were analyzed for the strain-13 guinea pig, an animal extensively utilized in the investigation of experimental disorders of demyelination. Our detailed analytical study of the normal guinea pig optic nerve provides the basis for comparison to disease states and the morphology of other species. As in the rat, mouse, and chipmunk, fiber diameters in the guinea pig were unimodal, but dissimilar to the trimodal fiber spectra of the cat and primate.

Antioxidant enzymes reduce loss of blood-brain barrier integrity in experimental optic neuritis.

We studied the effect of antioxidant enzymes on the loss of integrity of the blood-brain barrier in the optic nerves of strain-13 guinea pigs with chronic experimental allergic encephalomyelitis, a demyelinating disorder with neurologic and histopathologic characteristics similar to multiple sclerosis. Animals with experimental allergic encephalomyelitis received daily intraperitoneal injections of either preservative-free saline (group 1), catalase (group 2), or glutathione peroxidase (group 3) for 2.2 months after the onset of appendicular paralysis.

Acquired contralateral oculomotor synkinesis.

A patient with a traumatic right third nerve paresis had a contralateral oculomotor synkinesis develop that involved the left upper eyelid. With infraduction in adduction of the nonparetic left globe, the left upper eyelid was elevated. Elevation of the right upper eyelid was present in adduction of the paretic eye but absent in downgaze.

Experimental ocular herpesvirus infection in the cat. Sites of virus replication, clinical features and effects of corticosteroid administration.

Experimentally induced ocular feline herpesvirus 1 (FHV-1) infection was studied in 30 specific pathogen-free cats. In ten cats, the ability of five field isolates of FHV-1 to replicate in the epithelium and substantia propria of cornea and conjunctiva was demonstrated by histochemical techniques. Feline herpesvirus 1 was found to preferentially infect and induce necrosis of conjunctival epithelium.

Intracranial aneurysms with superior division paresis of the oculomotor nerve.

Five patients with intracranial aneurysms had unilateral ptosis, limitation of supraduction, and normal pupillary reactivity. The most common aneurysm location for superior division paresis of the oculomotor nerve was the superior cerebellar-posterior cerebral artery junction, where aneurysms (3) of the basilar artery compressed and flattened the interpeduncular oculomotor nerve from below. A superior cerebellar artery aneurysm and brain stem infarction affected the intra-axial course of the oculomotor nerve producing superior division paresis.

Methylprednisolone pulse therapy in severe dysthyroid optic neuropathy.

Five patients with severe dysthyroid optic neuropathy were treated with intravenous methylprednisolone (1 g daily for 3 consecutive days). Before administration, visual acuity of the more severely affected eyes of each patient was counting fingers at 5 feet, 8/200, 20/400, 20/200, and 20/80. Immediately after completion of pulse therapy, visual acuity improved to 20/25 in four patients and 20/30 in one.

Recovery of cyclic antidepressants with gastric lavage.

The role of lavage fluid volume in recovery of cyclic antidepressant with gastric lavage was determined in 13 patients treated for moderate to severe cyclic antidepressant intoxication. An orogastric tube was placed, gastric contents aspirated, and gastric lavage performed with 60 to 180 mL aliquots of tap water or 0.9% NaCl for irrigation.

T-lymphocyte subpopulations in acute unilateral optic neuritis.

The authors prospectively analyzed T-lymphocyte subpopulations in the peripheral blood of nine patients with acute unilateral optic neuritis and compared them with 25 controls without neurologic disease. The presence or absence of alterations in circulating T-cell subsets has not been examined previously in patients with isolated optic neuritis. The authors found the mean ratio of inducer (CD4) to suppressor (CD8) T-lymphocytes was 2.

Bilateral trochlear nerve paresis in hydrocephalus.

Three patients with nonneoplastic hydrocephalus had bilateral paresis of the trochlear nerves. Associated signs, including paresis of upgaze, light-near dissociation of the pupils, and convergence-retraction nystagmus, suggested rostral involvement of the mesencephalon. Trochlear nerve paresis and accompanying signs improved after revision of ventricular shunts in two patients.

Antioxidant enzyme suppression of demyelination in experimental optic neuritis.

Detoxification of hydrogen peroxide by the antioxidant enzyme catalase suppressed the neurologic manifestations of acute experimental allergic encephalomyelitis (EAE) and prevented death of treated adult strain-13 guinea pigs. The oxygen radical scavenger superoxide dismutase (SOD) delayed the onset of paralysis by one day, but did not prevent death from encephalomyelitis common to most of this group and all untreated animals. Histopathologic analysis of the optic nerves confirmed a statistically significant reduction in demyelination with catalase treatment, but not with SOD.

Surgical treatment of progressive visual loss in traumatic optic neuropathy. Report of two cases.

In two patients with traumatic optic neuropathy progressive visual loss was reversed by surgical decompression of the optic nerve sheath. The first patient with hemorrhage beneath the optic nerve sheath had progressive loss of vision from counting fingers to no light perception within 24 hours after the injury. Surgical evacuation of the hematoma improved visual acuity to 8/30.