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Biomedical subjects

R Lehman

Publications and source records attributed to R Lehman.

At least 19 recordsLinked to original sources
PubMed1993

Combined central retinal artery-central vein obstruction.

The cases of 23 patients with unilateral combined central retinal artery-central retinal vein obstruction are described. Criteria for the abnormality included: a history of relatively sudden visual loss; superficial retinal whitening in the posterior pole in combination with a cherry spot; and intraretinal blood, generally associated with dilated and/or tortuous retinal veins. In five instances (22%) the obstructions developed after retrobulbar injection. Among the 21 patients with followup for at least 6 months, or until the onset of neovascularization of the iris, 17 (81%) developed rubeosis iridis. Late histopathology was obtained in two eyes. Hemorrhagic necrosis of the retina was observed in some areas of the posterior pole and attenuation of the inner retinal layers, similar to that seen with late central retinal artery obstruction, was noted elsewhere. Periphlebitis of the central retinal vein within the optic nerve was found in each case.

Adult↗
PubMed1988

Bells against palsy.

A technique is described in which "jingle bells" are sutured in three positions on the face at the points of maximum excursion of the facial musculature when stimulated by a Hilger nerve stimulator set at 2 mA. The procedure is used to monitor movement of the facial nerve while the surgeon dissects the nerve in the cerebellopontine angle and internal auditory canal.

Facial Nerve↗
PubMed1985

The neuropsychological phenotype in Turner syndrome.

Numerous studies have demonstrated a significant depression in performance IQ (PIQ) in Turner Syndrome (TS) females, but the neuropsychological interpretation of this finding remains unclear. The present study addressed the following questions regarding the neuropsychological phenotype in TS: Are TS women neuropsychologically impaired? Is the impairment lateralized and How consistent is the neuropsychological phenotype across TS individuals? Unlike previous studies, the present study utilized both normal and brain damaged female controls. All subjects were given an extended Halstead-Reitan neuropsychological battery. The TS females were significantly worse than normals but not significantly different from brain damaged females in their overall level of neuropsychological functioning. However, their impairment was not lateralized. Their pattern of lateralizing findings was similar to that found in the Diffuse and Normal groups, but significantly different from either the right or left unilateral lesion groups. Fairly consistent deficits were found on tests of visuospatial skills and long term memory, but there was considerable variability in all the other test findings among TS individuals. The results are discussed in relation to the recent findings (Inglis and Lawson, 1981) that verbal-performance IQ discrepancies may be unreliable indicators of lateralized cerebral dysfunction in females. Hence the depressed PIQ in TS appears not to indicate predominantly right hemisphere dysfunction and may not even indicate a consistent underlying neuropsychological phenotype.

Dominance, Cerebral↗
PubMed1981

In vitro studies on susceptibility of enamel to caries attack after orthodontic bonding procedures.

Oral hygiene plays an important role in the prevention of caries. Therefore, when one is investigating the possible effects of acid etching on caries susceptibility, oral hygiene aspects and the supplementation of fluoride have to be considered. The objective of this investigation was to study the caries susceptibility of etched enamel surfaces in vitro. To simulate the in vivo situation, much attention was given to the influence of remineralization of saliva and fluorides. It was shown that etching and subsequently fluoridating and remineralization increases resistance of enamel against a caries attack.

Acid Etching, Dental↗
PubMed1981

Loss of surface enamel after acid etching procedures and its relation to fluoride content.

The etching of an enamel surface with a strong acid causes loss of surface contour together with a roughening of the enamel, which is necessary for proper adhesion of the bonding agent. It is known that the fluoride concentration plays an important role in the reduction of enamel solubility. The objective of this investigation was to measure the bulk enamel loss because of acid etching with phosphoric acid, with special emphasis on the fluoride content of tooth enamel. It was shown that fluoridated enamel has a high acid-resistant layer 2 to 4 microns in thickness. In some teeth the enamel is locally so resistant that, even after a 3-minute etching period, practically no material is removed. Since considerable amounts of topically applied fluoride ions are known to leak out, it is advisable to omit fluoride application shortly prior to the bonding procedure.

Acid Etching, Dental↗