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Biomedical subjects

S Brownstein

Publications and source records attributed to S Brownstein.

At least 55 records · Page 3Linked to original sources
PubMed1995

Vicryl-mesh wrap for the implantation of hydroxyapatite orbital implants: an animal model.

OBJECTIVE: To evaluate host fibrovascularization of hydroxyapatite orbital implants wrapped in sclera or in Vicryl (polyglactin 910) mesh in a rabbit model. NUMBERS: Eight adult New Zealand white rabbits that received hydroxyapatite orbital implants wrapped in homologous donor sclera (four animals) or Vicryl mesh (four animals). INTERVENTIONS: The rabbits had one eye enucleated and then received a 12-mm hydroxyapatite implant wrapped in sclera or Vicryl mesh. Magnetic resonance imaging (MRI) and bone scintigraphy were done to assess host fibrovascularization of the implant 4, 8, 12 and 20 weeks after implantation. Two animals (one in each group) were killed at each of these times, and the implant was removed for histopathological examination. MAIN OUTCOME MEASURES: Enhancement on MRI, uptake on bone scintigraphy, fibrovascularization seen on histopathological examination. RESULTS: The degree of fibrovascularization was substantial in all the specimens but appeared greater in the Vicryl-mesh-wrapped implants in the first 12 weeks after implantation on both histopathological and MRI studies. At 20 weeks these findings were similar in the two groups. A granulomatous foreign-body giant-cell reaction to both the Vicryl mesh and the implant itself was present up to 8 weeks after implantation. Bone scans showed only grade 1+ activity in all the implants. CONCLUSIONS: Host fibrovascularization in the rabbit appears to occur to a greater degree in Vicryl-mesh-wrapped hydroxyapatite implants than in those wrapped in donor sclera during the first 12 weeks after implantation. Vicryl mesh appears to be an acceptable alternative wrap for the hydroxyapatite implant, eliminating the need for donor sclera and its potential risks of transmissible diseases.

Animals↗
PubMed1994

Ocular findings in acromesomelic dysplasia.

We examined an infant who had prenatal onset of a skeletal dysplasia that had many features in common with acromesomelic dysplasia, including the clinical and light and electron microscopic findings of both corneas. Successful lamellar keratoplasty was performed on the left eye when histologic examination of the corneal button from the right eye showed that the corneal scar was only of partial thickness.

Cornea↗
PubMed1993

Fungal invasion of seven hydrophilic contact lenses.

In six patients we reviewed the clinical, microbiologic, and histopathologic findings of seven hydrophilic contact lenses that had been infiltrated by fungi. Three patients had visual blurring or irritation and redness while wearing a contaminated lens; of these, two were unaware of any lens deposits. Three of the lenses from two patients were spares kept in storage for six months and one year, respectively. One contaminated lens had been torn and was kept in a case while a loaner lens was worn. Culture of this lens grew Cladosporium species. The contact lens case from one patient grew Penicillium species. Gross pathologic inspection disclosed multiple brown deposits in five lenses, multiple gray infiltrates in one lens, and a white infiltrate in one lens. Light microscopic examination disclosed partial-thickness (three lenses) or full-thickness (four lenses) invasion of the lens matrix by fungi, which contained granular, brown pigment in six lenses.

Adolescent↗
PubMed1993

Trisomy 22 and facioauriculovertebral (Goldenhar) sequence.

We report on an infant girl born with complete trisomy 22 and left hemifacial microsomia, ear anomaly, and limbal and epibulbar complex choristoma. Trisomy 22 was confirmed by prometaphase chromosome analysis and in situ hybridization. This patient extends the list of chromosome abnormalities associated with apparent Golenhar sequence and emphasizes the importance of chromosome analysis in the investigation of patients with this condition. A detailed ophthalmopathological investigation is reported.

Abnormalities, Multiple↗
PubMed1993

Endocardial pacing, cardioversion and defibrillation using a braided endocardial lead system.

The clinical efficacy and safety of a second-generation braided endocardial pacing, cardioversion and defibrillation lead system was evaluated in 25 patients with ventricular tachycardia (VT) or ventricular fibrillation (VF). The lead system consisted of two 8Fr active fixation endocardial leads each with pacing and defibrillation electrodes and a thoracic patch electrode. Monophasic and biphasic shocks were delivered using a triple-electrode configuration with a right ventricular common cathode and right atrial and thoracic patch anodes. VT and VF were electrically induced. Rapid VT (rate > or = 180 beats/min) and VF were initially terminated by 20 J (550 V) shocks and slow VT (rate < 180 beats/min) by 10 J (400 V) shocks. One hundred fourteen episodes (rapid VT/VF 73, slow VT 41) were treated with 128 shocks (monophasic 80, biphasic 48). Mean ventricular pacing threshold was 0.7 +/- 0.5 ms before and 0.9 +/- 0.5 ms after endocardial shock delivery (p > 0.2). Mean ventricular electrogram amplitude in sinus rhythm was 11.9 +/- 5.7 mV before and 11.4 +/- 5.1 mV after shock delivery (p > 0.2). Simultaneous monophasic endocardial shocks terminated 53% of VF episodes at < or = 20 J. Simultaneous biphasic shocks terminated 94% of all VF episodes at < or = 20 J (p < 0.03). Efficacy of > or = 10 J shocks for rapid VT/VF was greater for biphasic (92%) versus monophasic (74%) shocks (p < 0.05) at lower average shock energy (15 +/- 7 J vs 19 +/- 7 J, respectively, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Immunocytochemical localization of taurine and glial fibrillary acidic protein in human optic nerve.

Taurine immunoreactivity (IR) in 1-microns sections of glutaraldehyde-fixed human optic nerve was observed using light microscopy and an antibody raised in rabbit to taurine conjugated to bovine serum albumin. Throughout the nerve, taurine-IR was prominent in glial cells, in their perinuclear regions, and in their numerous branching processes, some of which extended to the pial septa. The peripheral glial mantle (glia limitans) was densely stained, whereas axons and the pial septa showed relatively little or no taurine-IR. Immunoreactivity for glial fibrillary acidic protein (GFAP), and astrocyte-specific marker, was evaluated on adjacent sections. The pattern of GFAP-IR was highly similar to that for taurine, suggesting that a subset of taurine-immunoreactive glial cells are optic nerve astrocytes. To our knowledge, this is the first localization of taurine and GFAP in human optic nerve.

Adult↗
PubMed1992

Idiopathic conjunctival granulomas.

A 12-year-old white boy presented with a 1-year history of intermittent bilateral follicular conjunctivitis with yellowish bulbar and limbal nodules and few symptoms. Histopathological examination of conjunctival biopsy specimens showed non-caseating epithelioid cell granulomas with giant cell formation. The lesions partially responded to therapy with topical corticosteroids but persisted for another 4 years and then gradually cleared over the next 5 years. A systemic investigation failed to disclose a specific cause. At the time of writing, the nodules had completely resolved and no associated systemic disease had developed.

Child↗
PubMed1991

Gastric linitis plastica metastatic to the uvea.

A 59-year-old man underwent total gastrectomy for diffuse, poorly differentiated gastric adenocarcinoma diagnosed as linitis plastica. Loss of vision in the right eye 5 months later due to extensive choroidal tumours was the first indication of metastatic disease. Radiologic studies showed multiple bony metastases. The blind, painful eye was enucleated. Pathological examination of the globe showed massive metastatic mucus-secreting adenocarcinoma of the choroid, with positive immunohistochemical staining for carcinoembryonic antigen (CEA) of the foci of the more highly differentiated neoplastic cells. The plasma CEA level had been normal. The patient died 3 months after enucleation from metastatic disease.

Adenocarcinoma↗
PubMed1991

Ocular anomalies in anencephaly: a clinicopathological study of 11 globes.

Eleven globes of seven anencephalic infants with a gestational age of 36 to 41 weeks were examined pathologically. Atrophy of the ganglion cell and nerve fibre layers of the retina was found in all cases; optic nerve atrophy was noted in all 10 specimens in which the optic nerve was identified. In addition to findings attributable to immaturity, including persistent pupillary membrane (in 10 globes) and incomplete formation of the anterior chamber angle (in 5), we noted retinal dysplasia (in 4), colobomata (in 2) and proliferative retinopathy (in 1). Uncommon or previously undescribed abnormalities in association with anencephaly included cystic malformations of the meninges, sclera and globe (in one case each).

Anencephaly↗
PubMed1991

Schnyder's crystalline corneal dystrophy in association with hyperlipoproteinemia: histopathological and ultrastructural findings.

A 61-year-old man with Schnyder's crystalline corneal dystrophy showed a slight reduction in vision during 16 years of observation. Plasma lipoprotein analysis done 10 years after presentation showed type IIA hyperlipoproteinemia, which was also detected in one of four siblings examined, none of whom showed the characteristic corneal dystrophy. Electron microscopic studies on corneal biopsy specimens from the patient showed abundant crystalline material and vacuoles predominantly in the superficial corneal stroma, with occasional keratocytes and rare basal epithelial cells containing laminated structures. The findings of a focal continuity between the trilaminar membrane around some of the stromal vacuoles and the plasmalemma of the keratocytes as well as dissolution of the plasmalemma in other keratocytes are consistent with the hypothesis of a local cellular role in the development of this corneal disorder.

Cornea↗
PubMed1990

Immunoblastic T-cell lymphoma presenting as an eyelid tumor.

A 59-year-old white man presented with an ulcerating mass of the left upper eyelid of 6 months' duration. A biopsy specimen of the tumor was diagnosed as an immunoblastic T-cell malignant lymphoma. The lesion completely regressed after 4000 cGy of cobalt-60 radiation therapy. In the ensuing 33 months, multiple, widespread skin nodules of the same neoplasm developed including a right upper eyelid tumor. To the authors' knowledge, this is the first reported case of an immunoblastic T-cell lymphoma initially manifesting as an eyelid neoplasm.

Biopsy↗