Search PubMed⌕ Search

Biomedical subjects

M Rosner

Publications and source records attributed to M Rosner.

At least 55 records · Page 3Linked to original sources
PubMed1997

Reattachment of extraocular muscles using fibrin glue in a rabbit model.

PURPOSE: Reattaching extraocular muscles by the conventional suturing method may be complicated by scleral perforation. The attachment of extraocular muscles, using fibrin sealants, avoids such risk. The authors evaluated the use of fibrin sealant in a laboratory rabbit model. METHODS: Fifty-eight eyes of 29 rabbits were used in the study. In both eyes of each rabbit, the superior rectus muscle was disinserted, recessed, and either sutured or reattached to the globe by fibrin sealant. Two groups of eyes were compared. In one group (42 eyes), the recessed muscle was reattached using fibrin sealant. In the second group (16 eyes), sutures were used to reattach the recessed muscle to the globe. The insertion of the superior rectus muscle was examined 14 days after surgery, and histopathologic evaluation was performed 6 weeks after the surgery. RESULTS: Although in the sutured muscle group no slippage from the original placement was found, it was found in the group in which fibrin glue was used. The muscle slippage was greater at the small muscle recessions and smaller at the large muscle recessions. For muscle recession of 6 mm or more, the average muscle slippage was 0.12 +/- 0.28 mm, which was not statistically different from the suture group (P = 0.0828). CONCLUSIONS: Fibrin sealant was found to be effective for extraocular muscle reattachment only in large muscle recessions. However, in small muscle recessions the glue was not strong enough to overcome the contractive strength of the muscle.

Animals↗
PubMed1997

MK-801 has neuroprotective and antiproliferative effects in retinal laser injury.

PURPOSE: Treatment of the retina by laser photocoagulation often is complicated by an immediate side effect of visual impairment, caused by unavoidable, laser-induced destruction of healthy tissue adjacent to the lesion. A neuroprotective therapy that salvages this healthy tissue might enhance the benefit obtained from the treatment. This study was proposed to determine whether glutamate-receptor blockers can provide adjuvant neuroprotection during laser photocoagulation. The effect of MK-801, an NMDA-receptor antagonist, on laser-induced retinal injury was examined, in a rat model. METHODS: Argon laser lesions were created in the retinas of 36 DA rats, and were followed immediately by intraperitoneal injections of MK-801 (2 mg/kg) or saline. The animals were killed after 3, 20, or 60 days and the retinal lesions were evaluated histologically and morphometrically. RESULTS: Photoreceptor-cell loss was significantly less in MK-801-treated rats than in control animals. The proliferative membrane composed of retinal pigment epithelial cells and neovascular blood vessels, which was seen at the base of the lesion in control group retinas, was smaller in the MK-801-treated retinas. In rats treated with a higher dose of MK-801, the lesions showed almost no proliferative reaction. CONCLUSIONS: A potent noncompetitive NMDA-receptor blocker, MK-801 exhibits neuroprotective and antiproliferative properties in the retina. Glutamate-receptor blockers should be investigated further as potential adjuvant therapy in retinal photocoagulation treatments.

Animals↗
PubMed1997

Transcanalicular laser-assisted dacryocystorhinostomy.

BACKGROUND AND OBJECTIVE: Current techniques of laser-assisted dacryocystorhinostomy are mostly endonasal. In this report, the authors describe their technique of laser-assisted dacryocystorhinostomy performed through the canaliculi and the surgical results they achieved. PATIENTS AND METHODS: Fourteen patients with nasolacrimal duct obstruction underwent transcanalicular laser-assisted dacryocystorhinostomy. The bony ostium was perforated using a fiber optic-transmitting, giant-pulse Nd:YAG laser, with an energy of 0.5 to 4 J per pulse. The total energy used to create an ostium was 18 to 34 J. A silicone tube was inserted through the canaliculi and the ostium into the nasal cavity and kept in place for 5 to 7 months. Patients were observed for 18 to 22 months. RESULTS: Nine of the 14 patients (64%) reported the disappearance of epiphora following surgery. In 3 patients, no relief of epiphora was obtained. In 1 patient the operation was not completed because of severe nasal bleeding. In another, tearing began 12 months after surgery (6 months after tube removal). CONCLUSIONS: Transcanalicular laser-assisted dacryocystorhinostomy is a potentially useful method for performing dacryocystorhinostomy. Technical modifications and improvements are needed to increase the success rate.

Aged↗
PubMed1996

The first isolation, in vitro propagation, and genetic characterization of Ehrlichia canis in Israel.

Ehrlichia canis, the etiologic agent of canine ehrlichiosis, was isolated in Israel from a naturally infected dog with acute signs of the disease. The organism designated E. canis 611, was passaged experimentally to a beagle, from which it was propagated in primary canine monocytes. The organism was then grown in vitro in a continuous canine cell line, DH82. Nine beagles subsequently injected with whole E. canis-infected blood all developed typical symptoms of ehrlichiosis. An indirect immunofluorescence antibody test to E. canis was developed and compared with a commercial kit, revealing a good correlation between the two assays. Transmission electron microscopy of DH82 cells infected with the Israeli strain of E. canis (611), revealed organisms similar to those described in the literature: two different forms of morulae appeared, one tightly, the other loosely, packed. The 16S rRNA gene sequence obtained from the Israeli Ehrlichia isolate was compared with other isolates, E. canis Oklahoma and E. canis Florida. The Israeli strain 16S rRNA had three nucleotide differences from the Oklahoma isolate, and four nucleotide differences from the Florida isolate, in addition to one nucleotide gap in each. The Israeli isolate was found to be 0.54% different from the Oklahoma strain, and 0.61% different from the Florida strain. There are the same magnitudes of differences displayed by the other most closely related group in the phylogenetic tree, namely Ehrlichia equi, Ehrlichia phagocytophilia and the human granulocytic ehrlichia.

Animals↗
PubMed1996

Detection of ehrlichial antigen in plasma of beagle dogs with experimental acute Ehrlichia canis infection.

Six beagles were experimentally infected with Ehrlichia canis. All dogs developed typical clinical signs of ehrlichiosis and sero-converted. Ehrlichial antigenemia in the plasma of the infected dogs was detected using a sandwich enzyme-linked immunosorbent assay (ELISA). Ehrlichial antigen was present starting 15-20 days post-infection, after the development of clinical signs and antibody titre to Ehrlichia canis. The appearance of ehrlichial antigen in the plasma for a relatively short and variable period after the clinical and haematological signs, limits its potential as an early diagnostic prognosticator of canine ehrlichiosis.

Animals↗
PubMed1996

Infected orbital cyst following exenteration.

An orbital cyst is a rare complication of orbital trauma and exenteration. Infections of such cysts have not been described, and are potentially dangerous unless treated immediately. The authors describe a case of delayed treatment of such an infected cyst, which resolved following surgical drainage. The potentially hazardous outcome makes knowledge of such cases important.

Aged↗
PubMed1995

Bilateral diffuse iris nodular nevi. Clinical and histopathologic characterization.

BACKGROUND: Diffuse nodular nevus of the iris is an uncommon condition that presents with multiple verrucous excrescences distributed diffusely on the iris surface. METHODS: The authors describe 30 patients with bilateral diffuse iris nodular nevi and report associations with bilateral congenital cataract, neurofibromatosis, oculodermal melanocytosis, congenital ptosis, morning glory anomaly, Axenfeld anomaly, or Peters anomaly. RESULTS: Iris nodules were uniform in size and distribution and were brown, as was the surrounding iris. Light and electron microscopy of iridectomy specimens from one patient showed elevated plaques composed of aggregates of plump, lightly pigmented nevoid cells interwoven with mature, densely pigmented spindle-shaped uveal melanocytes. CONCLUSIONS: The authors report the largest clinical series and first ultrastructural description of bilateral diffuse iris nodular nevi, which represents a variant of neural crest development. No ocular complications could be attributed to the iris nodules, which should be differentiated from Lisch nodules and other pathologic iris lesions.

Adolescent↗
PubMed1995

Conjunctival melanomas.

BACKGROUND: The nomenclature and the clinical and pathologic features of cutaneous and conjunctival melanomas are different. A comparison is made to familiarize dermatologists and ophthalmologists with these differences. METHODS: Five cases of conjunctival malignant melanoma from December 1983 to December 1990 were reviewed. RESULTS: The nomenclature of primary acquired melanosis is not used for cutaneous melanomas, and terms such as dysplasia and Clark's nevus are not used for conjunctival melanomas. Technical difficulties exist in orienting thin conjunctival tissues because of a tendency to curl during fixation, resulting in tangential sectioning and making a false diagnosis of a prognostically ominous pagetoid spread for an otherwise banal basilar hyperplastic pattern. Excision, cryotherapy, and rarely exenteration are the therapeutic measures in managing conjunctival melanomas; these have far more serious consequences for the patient compared with the excision of a skin melanoma. CONCLUSION: Differences exist in several aspects between melanomas located in the skin and the eye.

Adult↗
PubMed1995

Physiological studies of visual cortex reorganization following cortical deafferentation in neonatal cats.

Whether restoration takes place in the visual cortex of neonates was physiologically studied in cortical cells of cats following their deafferentation. Deafferentation was performed by a parasagittal incision made in the visual cortex, separating the medial part of it from the thalamocortical and other visual fibers. Responsiveness (percentage of responsive cells) in the middle zone (the middle sector along the cortical incision) of the deafferented region was 82.5%, compared with 91.7% in the afferented (lateral to the incision) region (p = 0.5). In comparison, the responsiveness level was 32.3 and 81.3% (p < 0.05) in the respective zones of the similarly deafferented adult controls. The ocular dominance distribution and binocularity were almost normal in the deafferented region of the neonatally operated cats, whereas binocularity was remarkably diminished in the adult controls. Recovery was also found in the specificity of the cells to orientation and direction in the neonatally operated cats, but not in the adult-operated cats. Thus, functional reorganization of the columnar organizations takes place in the neonatally deafferented but not in the adult-operated cats.

Age Factors↗
PubMed1994

[Merkel cell carcinoma of the eyelid].

Merkel cell carcinoma is an infrequent but highly malignant cutaneous neoplasm. In a 73-year-old woman, a Merkel cell carcinoma of the right upper lid developed within 1 month, recurred within a month after its first removal, and metastasized to the parotid 2 months after secondary excision.

Aged↗
PubMed1994

Patient dissatisfaction after functionally successful conjunctivodacryocystorhinostomy with Jones tube.

Conjunctivodacryocystorhinostomy with a Jones tube is an accepted procedure for the treatment of epiphora resulting from obstructed canaliculi. Because of our clinical impression that a high rate of functional success after surgery is associated with a lower rate of patient satisfaction, we analyzed the results and patient satisfaction of 121 patients who underwent conjunctivodacryocystorhinostomy with Jones tubes. The surgical success rate was 92.6% (112 of 121 patients). However, 13 of 112 patients (11.6%) whose operation was functionally successful were not satisfied and 36 of 112 patients (32%) reported having more complications than expected. The highest rate of dissatisfied patients occurred in patients 70 years of age or older (ten of 46 patients, 22%) and in patients 19 years of age or younger (one of four patients). Thus, the indication for conjunctivodacryocystorhinostomy in these age groups should be limited to exceptionally remarkable symptomatic cases. The drawbacks of the procedure should be explained to all candidates to minimize dissatisfaction resulting from unrealistic expectations.

Adolescent↗
PubMed1993

Dose and temporal parameters in delaying injured optic nerve degeneration by low-energy laser irradiation.

Low-energy laser irradiation has been reported to postpone the degenerative processes in crushed optic nerves of rats, which are part of the nonregenerable mammalian central nervous system. In the present study, we evaluated the optimal irradiation parameters for this purpose. Optic nerves of 141 rats were subjected to crush injury and then irradiated through the eye, starting at different points of time before or after the injury, for different durations and periods, using various intensities of either helium-neon laser or noncoherent infrared light (904 nm). The effect was evaluated by measurements of the compound action potentials of the nerve segments between the site of injury and the optic chiasm. The compound action potential amplitude of the crushed nonirradiated nerves, as measured 2 weeks after the injury, was found to be 0.51 +/- 0.30 mV, in contrast to 3.10 +/- 1.03 mV measured in 232 normal nerves. Irradiation with a 10.5 mW helium-neon laser for 2 and 3 min once a day for 14 consecutive days resulted in maximal preservation of action potentials (1.78 +/- 0.72 and 1.95 +/- 0.71 mV, respectively). Irradiations beginning immediately prior to the injury were as effective as irradiations beginning soon after it. Irradiations for longer than 3 min or twice a day aggravated the damage. Noncoherent infrared light was ineffective or adversely affected the injured nerves. Our experiments suggest that optimal delay of posttraumatic optic nerve degeneration in rats is attainable with 10.5 mW helium-neon laser irradiations for 2 or 3 min once a day for 14 consecutive days.

Action Potentials↗
PubMed1993

Corneal electrode for recording electroretinograms in rats.

The corneal contact lens electrode, because of its convenience, has replaced the cotton-wick electrode for recording electroretinograms from patients and animals such as dogs, rabbits, and cats. The cotton-wick electrode, however, remains popular for rat electroretinogram measurements because small contact lens corneal electrodes that fit rat eyes are difficult to fabricate. We prepared corneal electrodes from disposable needles for use in recording electroretinograms from rats. The electrodes were readily prepared, were inexpensive, and were used successfully in six rats.

Animals↗