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Biomedical subjects

M Lazar

Publications and source records attributed to M Lazar.

At least 91 records · Page 5Linked to original sources
PubMed1993

Pneumomediastinum following blowout fracture of the medial orbital wall: a case report.

An unusual case of cervical emphysema and pneumomediastinum following a blowout fracture of the medial orbital wall is presented. Severe pulmonary distress did not occur, and the trapped air rapidly absorbed. The source of the emphysema and its progression is discussed considering the anatomic relations of the facial and cervical subcutaneous space and the mediastinum. To our knowledge, this complication is rare and has been documented only once before in an isolated blowout fracture of the orbit.

Humans↗
PubMed1993

Intentional retention of Descemet's membrane in keratoplasty for the surgical treatment of bullous keratopathy.

We report on a modified keratoplasty procedure performed in 6 patients for the treatment of severe pseudophakic bullous keratopathy. While removing the host's cornea, the Descemet membrane was retained, and a full thickness graft sutured on top of it. Postoperatively, aqueous separated the host's Descemet membrane from the graft, thus forming a supernumerary anterior chamber. The graft remained clear in 5 of these patients during up to 28 months of follow-up. We suggest that in some severely damaged and high risk eyes, where opening the anterior chamber might be associated with difficulties and complications, it could be worthwhile to perform an 'extraocular' procedure by retaining the host's Descemet membrane.

Aged↗
PubMed1993

Variable phenotypic expressivity of Best's vitelliform dystrophy.

Two families with Best's vitelliform macular dystrophy (BVMD) were investigated ophthalmoscopically and electrophysiologically. Pedigree examination confirmed the autosomal dominant heredity of this disorder with variable expressivity. Extrafoveal vitelline deposits were present in some asymptomatic patients, strongly suggesting that these deposits represent variable expressivity of familial BVMD.

Adolescent↗
PubMed1993

[Excimer laser correction of myopia].

Excimer laser photorefractive keratectomy was performed on 100 myopic eyes. The preoperative spherical equivalent of myopia ranged from -2.00 to -9.99 diopters (D), mean -4.80 +/- 2.20 D. The procedure was performed under local anesthesia using 0.4% topical benoxinate HCl; corticosteroid eye drops were then used for up to 3 months. All patients achieved corrected visual acuity within 1 line of corrected preoperative visual acuity. The only complication was subepithelial reticular haze seen in all patients, which peaked at 4 weeks after the procedure and gradually diminished within 3 months. After follow-up of from 6-11 months, 93% of patients had achieved uncorrected visual acuity of 6/12 or better. Mean postoperative refraction was -0.20 +/- 0.97 D. 69% achieved a correction within +/- 0.50 diopter of emmetropia, 85% within +/- 1.00 D and 96% achieved corrected visual acuity of within 1 line of preoperative corrected visual acuity. This study and those in the literature show excimer laser to be a promising surgical treatment for myopia.

Follow-Up Studies↗
PubMed1993

Drug-induced retinal toxicity in albino rabbits: the effects of imipenem and aztreonam.

PURPOSE: To test the toxic action of two antibiotics, imipenem and aztreonam, on the functional and morphologic integrity of the albino rabbit retina. METHODS: Two commercial drugs were used--Tienam, which contains imipenem, and Azactam, which contains aztreonam. Different doses of these drugs were injected intravitreally. Retinal function was assessed from the electroretinogram (ERG) and the visual evoked potential (VEP). Retinal structure was examined at the light microscopic level. RESULTS: Imipenem did not affect the ERG and the VEP responses or the morphology of the retina up to a total injected dose of 0.98 mg (2 mg Tienam). Aztreonam was not toxic to the albino rabbit retina up to a total injected dose of 2.8 mg (5 mg of Azactam). Severe functional and morphologic retinal damage was seen when 10 mg of Azactam was injected. A similar degree of damage was seen when a dose of 5 mg L-arginine, an ingredient of Azactam, was injected into the vitreous. CONCLUSIONS: Imipenem and aztreonam are nontoxic to the albino rabbit retina at concentrations that are 500-fold higher than their effective dose against bacterial infection. Azactam is highly toxic at high levels (more than 10 mg injected into the vitreous). Most of the toxicity could be explained by the L-arginine content of the drug.

Animals↗
PubMed1993

Cisplatin and doxorubicin for invasive basal cell carcinoma of the eyelids.

Cisplatin and doxorubicin were used in the treatment of recurrent invasive basal cell carcinoma (BCC) of the medial canthus and orbit. Complete remission was observed after treatment termination, and this was still evident five years later. Systemic chemotherapy offers an alternative mode of treatment for selected cases of advanced BCC.

Aged↗
PubMed1993

The effects of myristyl gamma-picolinium chloride on the rabbit retina: morphologic observations.

PURPOSE: This study was designed to localize the site of action of myristyl gamma-picolinium chloride (MGP) in the rabbit retina and to evaluate the extent of the structural damage induced by the drug. METHODS: The structural damage was assessed at the light microscopic level in eyes treated with various concentrations of MGP at different time intervals after intravitreal injection of the drug. Glial fibrillary acidic protein (GFAP) immunoreactivity was tested in the same eyes and served as an index of retinal damage. RESULTS: The rabbit retinas, examined about 1 mo after MGP injection, exhibited loss of photoreceptors and thinning of the retina in the regions close to the site of injection; remote retinal areas appeared morphologically intact or only slightly affected. Immunocytochemical analysis demonstrated the presence of GFAP in Müller (glial) cells throughout the entire retina. When the effects of MGP were examined at short time intervals (24 and 72 hr) after injection, severe morphologic damage in areas adjacent to the site of drug injection developed in parallel with the electroretinographic findings. However, GFAP could not be demonstrated. CONCLUSIONS: MGP, the preservative used in Depo-Medrol (Upjohn, Kalamazoo, MI), is highly toxic to the rabbit retina.

Animals↗
PubMed1993

Retinal detachment as a complication of neodymium: yttrium aluminum garnet laser cyclophotocoagulation.

We report a traction retinal detachment that developed within one month of transscleral neodymium: yttrium aluminum garnet (Nd:YAG) laser cyclophotocoagulation, a previously unreported complication of the new cyclodestructive procedure. A 17-year-old boy was referred to our department with uncontrolled aphakic glaucoma OD after having undergone cyclocryotherapy twice. Three treatments with transscleral Nd:YAG cyclophotocoagulation were done over nine months to lower his intraocular pressure. Hypotony and traction retinal detachment occurred after the third laser treatment and was managed successfully by vitrectomy with a fluid-gas exchange. Thus, the possibility of this additional complication should be remembered when doing transscleral Nd:YAG cyclophotocoagulation.

Adolescent↗
PubMed1992

[Acute systemic side-effects of topical timolol for glaucoma].

Topically-administered ophthalmic medication may reach clinically significant serum concentrations, as evidenced by the variety of systemic side effects reported. These drugs may interact with other drugs administered orally and intravenously, increasing the frequency and severity of their side-effects. We report 4 patients examined in the emergency room because of various systemic manifestations, in whom the symptoms could be attributed either to antiglaucomatous eye drops, or to interaction between these eye drops and systemic medication. Considering the high incidence of glaucoma (0.5-2%), physicians should be aware of the systemic side-effects of antiglaucomatous eye drops and of possible interaction between such treatment and systemic medications.

Aged↗
PubMed1992

Dosing problems in the use of topical ophthalmic drops.

The effect of two drops of the same drug, one instilled immediately after the other, was compared to the effect of a single drop in 100 healthy volunteers. The drugs investigated were tropicamide, 0.125%, and phenylephrine, 2.5%. The mydriatic effect of two drops was 30%-35% stronger than the effect achieved by a single drop.

Adult↗
PubMed1992

Activation of the gene encoding the glycolytic enzyme beta-enolase during early myogenesis precedes an increased expression during fetal muscle development.

We define the spatial and temporal patterns of expression of the gene encoding the glycolytic enzyme, beta-enolase, during mouse ontogenesis. Transcripts were detected by in situ hybridization using 35S labelled cRNA probes. The beta-enolase gene is expressed only in striated muscles. It is first detected in the embryo, in the cardiac tube and in newly formed myotomes. In the muscle masses of the limb, beta gene expression occurs at a low level in primary fibers, and subsequently greatly increases at a time which corresponds to the onset of innervation and secondary fiber formation. Later in development, it becomes undetectable in slow-twitch fibers. Our results demonstrate the multistep regulation of the beta-enolase gene. The regulation of this muscle-specific gene in somites is discussed in terms of the myogenic sequences of the MyoD family shown to be present when it is activated.

Animals↗
PubMed1992

Modulation of embryonic and muscle-specific enolase gene products in the developing mouse hindlimb.

During striated muscle development, the glycolytic enzyme enolase (EC 4.2.1.11) undergoes an isozymic transition, from the embryonic alpha alpha form towards the muscle-specific forms alpha beta and beta beta. The regulation of this transition was analyzed in mouse hindlimb muscles from embryonic day 15 (E15) to the adult stage. The quantitative modulations of the levels of the transcripts and subunits of alpha and beta enolase genes were determined. The absolute amounts of alpha and beta enolase mRNAs were estimated using in vitro synthesized transcripts as calibration standards, thus allowing an evaluation of their relative contribution at each stage examined. The muscle-specific beta enolase mRNA is already present at E15. Its level then increases and, from E17, this transcript becomes predominant. This accumulation is biphasic: a steep prenatal rise, corresponding to a net increase per fiber, accompanies the formation of secondary myofibers and the development of innervation; a second rise, beginning at postnatal day 5, is temporally correlated with the definitive specialization of the myofibers. Most of the decrease in alpha mRNA level occurs postnatally. No temporal or quantitative correlation between the up-regulation of beta mRNA and the down-regulation of alpha mRNA levels is observed throughout hindlimb muscle development. Quantitative immunoblotting analyses carried out in parallel show that the enolase isozymic transition is mainly controlled at the mRNA level.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗