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Biomedical subjects

P Nemet

Publications and source records attributed to P Nemet.

At least 55 records · Page 3Linked to original sources

Chloramphenicol optic neuropathy.

Three patients with cystic fibrosis of the pancreas initially were seen because of optic neuropathy caused by a toxic reaction to chloramphenicol. The ocular symptoms were characterized by loss of visual acuity, central scotomas, red-green dyschromatopsia, and fundus changes. An increase in the latency of the occipital evoked potentials paralleled the visual impairment. A transient photopic decline in the red-light-elicited electroretinogram and the occurrence of Uhthoff's sign in the acute stage of the disease were observed. All visual impairment recovered partially or totally after the withdrawal of therapy with the drug.

Adolescent↗

Retinal detachment in median cleft-face syndrome.

A 7-year-old boy had an unusual association of median cleft-face syndrome, a characteristic physiognomy, unilateral retinal dysplasia, and bilateral retinal detachment. Despite surgical treatment to both eyes he became blind. The hereditary pattern operating in this complex disorder was found to be consistent with an autosomal dominant trait.

Child↗

Sector retinitis pigmentosa in juvenile nephronophthisis.

In a patient with juvenile nephronophthisis, sector retinitis pigmentosa was found as an extrarenal manifestation, establishing a hitherto undescribed variety of retinal degeneration occurring in this disorder. The retinal function in this case was identical with that in the classic type of sector retinitis pigmentosa, namely, subnormal ERG amplitudes but normal cone and rod implicit times. The range of the retinal findings and their autosomal recessive transmission are discussed. Paucity of information makes it difficult to elucidate the basic genetic defect operating in this condition.

Adolescent↗

Ultrastructure of the conjunctiva, skin, and gingiva: a case of Sandhoff's disease in a Jewish patient.

Pleomorphic membranous cytoplasmic bodies that indicated glycolipid storage were found in the conjunctiva, skin, and gingiva of a Jewish patient with Sandhoff's disease. The clinical symptoms were typical of GM2 gangliosidosis. Both hexosaminidase A and hexosaminidase B activities were deficient in the leukocytes and serum. Glycosaminoglycan levels in cultured fibroblasts were elevated. Membranous cytoplasmic bodies were observed in high concentrations in a large proportion of the vascular endothelial cells, pericytes, and Schwann cells and to a somewhat lesser extent in the fibrocytes of all tissues studied. Ultrastructural analysis of the conjunctiva, skin, and gingiva as an aid for the diagnosis of Sandhoff's disease is suggested.

Capillaries↗

Retinal manifestations in familial juvenile nephronophthisis.

Three families affected by juvenile nephronophthisis are described and genetically analyzed. The extrarenal manifestations of the disease include retinal findings such as congenital Leber amaurosis, retinitis pigmentosa and sector retinitis pigmentosa. Autosomal recessive transmission and the wide phenotypic spectrum are discussed. The variability in the retinal findings is explained by the presence of a pleiotropic gene with variable expressivity.

Adolescent↗

Congenital ocular motor apraxia--familial occurrence.

The occurrence of congenital oculomotor apraxia in two children of the same family is described. The improvement of the ocular dysfunction in the older sister gave some hints to the benign nature of the condition and its tendency to recover with age. The possible pathophysiological mechanism underlying this anomaly is discussed.

Adolescent↗

Falciform fold of retina.

A boy of 2 had evidence of congenital retinal non-attachment. The mother had a veil like fold in one eye. There was no evidence of any systemic disorder. The inheritance might be X-linked recessive. Mild manifestations of the disease in the carrier mother may be more frequent than has been assumed and should be looked for.

Child, Preschool↗

Ocular saccades in Duane's syndrome.

Since Hering's law might be affected when paradoxical innervation exists, 10 patients with Duane's syndrome were studied. Eye movements were measured by binocular recording of electro-oculogram. Our study shows clearly that the sound eye's motility is also affected. When adduction of the affected eye is present, Hering's law holds, whereas when adduction is limited this law cannot be demonstrated.

Adolescent↗

Cerebellar role in smooth pursuit movement.

It is generally believed that pursuit eye movements are unaffected by cerebellar cortical atrophy or cerebellectomy. The present study was performed on patients who underwent partial vermis and hemisphere ablations as a result of severe cranial injury or cerebellar tumors. Eye movements were measured by DC electro-oculography. A clear disparity of the slow phase of the optokinetic nystagmus was observed. When eye movements were contralateral to the ablated side the slow phase of optokinetic nystagmus was statistically slower than drum or visual field velocity. It is suggested that the cerebellum network is involved in the mechanisms of the smooth pursuit movement.

Brain↗

The cerebellum involvement in the generation of saccades.

It was assumed that the cerebellum is not essential for eye movements, playing only a modifying and influencing role. Recently it has been shown that the directions of the saccades can be related to a stimulated cerebellar site. This study was done on patients who underwent partial vermis and hemisphere ablations as a result of severe cranial or cerebellar tumors. The results further indicate that lack that lack of some cerebellar neural structure affects the nature of the saccade: it does not move the eyes in one saccade to acquire the new target and its amplitude duration relationship changes. It is suggested that cerebellar cortex generates a neural pulse based on teleceptive information about stimulus location with respect to an observer's head, corrects this information for initial eye position and sends out a signal to the saccadic pulse generators which move the eyes to acquire the new target.

Brain↗

Jadassohn-type anetoderma in association with keratoconus and cataract.

The unusual association of macular atrophy--Jadassohn type of anetoderma, bilateral subcapsular ocular cataracts and keratoconus--is described in an otherwise healthy adult male. This association has not, to the best of our knowledge, been previously described. The possibility that this is not a chance association is discussed.

Atrophy↗

Sympathetic pupillary activity in infants.

In an attempt to learn the contribution of the sympathetic system to smaller pupillary size in infants, pupillary responses were tested to agents acting on this system in 12 ihfants and 23 young adults. Phenylephrine dilated the pupils of both groups by the same ratio, with infants' pupils reaching a lesser diameter. The responses to cocaine and hydroxyamphetamine were lower in children. It is concluded that in the first months of life the postganglionic sympathetic nerve releases less norepinephrine. This may be due to a lower number of sympathetic neurons. The post-synaptic apparatus may not be fully developed in infants.

Adolescent↗

Miochol-induced transient cataract.

Acute transient lens opacity occurred in a patient with ruptured cornea following injection of Miochol into the anterior chamber. It is postulated that the lens changes were due to osmotic effect of the hypertonic Miochol solution.

Acetylcholine↗

Sympathetic pupillary tone in old age.

In an attempt to determine whether autonomic neural factors might be involved in senile miosis, we tested pupillary responses to agents acting on the ocular sympathetic system in old subjects and compared them to responses in young adults. Our results suggest that sympathetic tone is decreased in the elderly. The dilator pupillae muscle does not lose its sensitivity to norepinephrine with age.

Adolescent↗