Search PubMed⌕ Search

Biomedical subjects

A Sugar

Publications and source records attributed to A Sugar.

At least 91 records · Page 5Linked to original sources
PubMed1985

Reactive cellular membrane on a glass fragment after two years in the anterior chamber.

An optically clear membrane composed of a continuous proteinaceous film and sessile cells of macrophage origin was present on the surface of a glass fragment removed from the anterior chamber of the eye of a nine-year-old boy almost two years after a perforating corneal injury. This finding indirectly contributes to the understanding of membranes formed by the inner eye during adaptation to an intraocular lens implant.

Anterior Chamber↗
PubMed1985

Specular microscopic follow-up of corneal grafts for pseudophakic bullous keratopathy.

Pseudophakic bullous keratopathy (PBK) has become the leading indication for penetrating keratoplasty. In our initial fifty patients having keratoplasty for PBK there was gradual loss of clear grafts in patients with retained intraocular lenses (IOLs). Specular microscopy was performed on donor tissue, and periodically postoperatively, for 130 grafts for PBK. The highest cell loss at one year was in eyes with retained iris support (39.2%) or anterior chamber (37.2%) IOLs. Cell loss in grafts with removed iris support IOLs (21.3%) was significantly less. When iris support IOLs were exchanged for anterior chamber (AC) IOLs, the cell loss at one year (27.1%) was intermediate. We recommend that iris support IOLs be removed at keratoplasty. Exchange for an AC IOL should be considered depending on the visual needs of each patient. Removal of AC IOLs should be based on consideration of prior tolerance and position of the implant.

Aged↗
PubMed1985

Surgical treatment of calcific band keratopathy.

A surgical technique utilizing ethylenediaminetetraacetic acid (EDTA) and a Fisch drill with a diamond burr for removal of calcific band keratopathy is presented. Use of a diamond burr is an effective and simple method of removing resistant calcium deposits from the cornea without causing significant scarring.

Adolescent↗
PubMed1985

Dependence on antibody for induction of chemiluminescence in polymorphonuclear leukocytes by herpes simplex virus.

The induction of luminol-dependent chemiluminescence in rabbit polymorphonuclear leukocytes (PMN) by a stromal keratitis causing strain (RE) of herpes simplex virus type 1 (HSV-1) was examined. Virus alone and virus infected rabbit corneal cells were unable to stimulate chemiluminescence. However, when the virus or virus infected cells were incubated in the presence of HSV-1 specific immune serum or purified IgG, a gradual chemiluminescent response was observed. Virus and virus infected cells incubated with normal rabbit serum or IgG produced little or no activity. No impairment of chemiluminescent response was observed in experiments in which rabbit PMN were exposed to HSV prior to the addition of opsonized zymosan or HSV-antibody complexes. Results suggest PMN exert antiviral activity in the presence of specific antibody and may be important factors in the inflammatory process resulting from ocular HSV infection.

Animals↗
PubMed1985

Reactive membranes on posterior chamber lens implants.

The cytopathology of two types of membranes on surgically removed posterior chamber lens implants is described on the background of the clinical histories. Both implants exhibit film-like proteinaceous capsules with numerous cells of macrophage origin in one case and virtually without cells in the other.

Aged↗
PubMed1984

Intrastromal crystalline deposits following corneal graft rejection.

Five patients were noted to develop fine crystals in the corneal stroma following rejection of corneal grafts. Four had penetrating, and one lamellar, keratoplasty. All recovered from rejection after steroid therapy. The crystals were fine, gray to tan, refractile, not associated with visual loss, and stable over several months of follow-up. We speculate that these crystals may be related to immune globulin or immune complex deposition, although they may be lipid left after resolution of inflammatory infiltrate.

Administration, Topical↗
PubMed1983

Demographic and predisposing factors in corneal ulceration.

We identified 224 patients hospitalized with corneal ulcerations at the University of Michigan Hospitals, Ann Arbor, between May 1975 and September 1981, and performed a chart review on a random sample of these cases. Bimodality in the patients' age distribution was attributed to nonsurgical ocular trauma in the younger group, and predisposing keratitis, surgical trauma, bullous keratopathy, and entropion in the older group. Bacterial and postherpetic causes accounted for 52 (52%) of the sampled cases. Pseudomonas aeruginosa and Staphylococcus aureus were the major isolates. Important predisposing factors included nonsurgical and surgical trauma, herpetic keratitis, contact lens wear, corticosteroid therapy, and bullous keratopathy. Both age and visual acuity on admission had prognostic implications for improvement in visual acuity after treatment.

Adult↗
PubMed1983

A randomized trial of pressure patching for epithelial defects after keratoplasty.

A prospective randomly controlled trial of the effectiveness of pressure patching in the treatment of epithelial defects after keratoplasty in 41 patients (19 in the patched group and 22 in the unpatched group) showed no significant differences in healing between the two groups (P less than .25 to P less than .49 on postoperative days 1 to 6). The mean time needed for complete healing was 2.11 days in the patched group and 2.09 days in the unpatched group. Patients with bullous keratopathy preoperatively had larger initial defects (31.4 mm2) than those without (20.1 mm2) but the time needed for healing did not differ significantly (2.35 days vs 1.9 days; P less than .10).

Bandages↗
PubMed1982

Recurrence of lattice corneal dystrophy type 1 in the corneal grafts of two siblings.

Amyloid was identified by light and electron microscopy within corneal grafts of two male siblings from a family with lattice corneal dystrophy type 1. These deposits indicate a recurrent disease within the donor tissue, and we believe this reflects an infiltration of the grafts by genetically abnormal host corneal fibroblasts. One of the patients developed bilateral recurrent disease in the grafts eight and 13 years after penetrating keratoplasty. His brother required a regraft 16 years after a penetrating keratoplasty. Although both of these patients required regrafts because of impaired visual acuity, the decrease in visual acuity in one case was not solely the result of reaccumulation of amyloid, but was at least in part caused by a plaque of fibrous tissue behind the cornea.

Adult↗
PubMed1982

Penetrating keratoplasty in the cat. A clinically applicable model.

A series of 28 consecutive penetrating keratoplasties were performed on adult cats. Donor corneas (n = 14) were maintained in culture medium for 14--24 hours prior to transplantation. Rotational autografts (n = 7) were used to control for cell loss caused by culture maintenance as well as for the effects of surgery. Additional homografts (n = 7) were transplanted following removal of the corneal endothelium to study the extent of host corneal endothelial cell regeneration. Pre- and post-operative endothelial cell counts of the homografts made from specular micrographs demonstrated an average cell loss of 30% one month following surgery. A similar 30% average cell loss was present in the rotational autografts. Clinically, both homografts and autografts remained clear and were near normal in thickness. Homografts lacking endothelium exhibited persistent, severe edema that correlated with the inability of the host corneal endothelium to resurface the graft. Clinical and morphologic evidence of mild homograft rejection as observed in 15% of the animals that received normal homografts. Corneal endothelial cell loss following penetrating keratoplasty in the cat approximates that observed following the same procedure in the human. Additionally, regenerative capacity of the corneal endothelium in the cat, like that of the human, is limited. These features suggest that this cooperative, hardy animal is an excellent model in which to study many aspects of corneal transplantation that have direct application to the treatment of human corneal disease.

Animals↗
PubMed1982

Evaluation of coated and uncoated synthetic absorbable sutures in rabbit limbal wounds.

Polymer coatings have been applied to braided synthetic absorbable sutures to decrease tissue drag and improve knot tying characteristics. To examine the possibility that increased "slipperiness" would decrease knot security, coated (Dexon Plus) and uncoated (Dexon S) polyglycolic acid sutures were compared in rabbit limbal wounds. Both suture types had comparable knot security, tissue reaction, and absorption rates, while the coated sutures caused less tissue drag. Clinical trials of coated polyglycolic acid suture for limbal wounds are warranted.

Absorption↗
PubMed1982

Iron deposits surrounding multiple sclerosis plaques.

Autopsy samples from cerebral areas of five brains from patients with multiple sclerosis (MS) and from six control brains were stained with Perls acid ferrocyanide to detect nonheme iron present as hemosiderin. Positive iron reactions were observed only in MS sections surrounding demyelinated plaques. Myelinated white matter near the lesion contained numerous iron-laden ovoid bodied and axons that stained positively for iron. Positive reactions were also found within blood vessels of gray matter near the lesion. A possible source of the iron was extravasated blood.

Adult↗
PubMed1981

Giant papillary conjunctivitis after keratoplasty.

Giant papillae of the upper tarsal conjunctiva have been found in vernal conjunctivitis and, more recently, in giant papillary conjunctivitis in patients with contact lenses. A similar syndrome occurred in 11 patients who had undergone penetrating keratoplasty with interrupted nylon sutures. Minimal itching, mild mucous discharge, mild blepharoptosis, and giant papillae of the upper tarsal conjunctiva were associated with exposed suture ends. Removal of exposed sutures led to resolution of the condition. Conjunctival scrapings from three of five patients demonstrated eosinophils. Although the syndrome may have an immunologic basis, the findings are also consistent with a mechanical origin related to exposed nylon sutures.

Adolescent↗
PubMed1981

Endothelial physiology and intraocular lens implantation.

The endothelium is the cellular monolayer which lines the posterior surface of the cornea. This layer is important in clinical ophthalmology because it is vital to maintenance of the transparency of the cornea and vision through its pump and barrier functions which limit the ingress of fluid into the cornea from the aqueous. When the function of the corneal endothelium becomes compromised, the corneal stroma swells as it hydrates. Subsequently, epithelial bullae form with painful recurring epithelial erosions, and finally corneal scarring and blindness result. The relatively vulnerable position of the corneal endothelium renders it susceptible to iatrogenic injury during intraocular procedures, especially IOL implantation: the poor regenerative (mitotic) capacity of the human corneal endothelium limits its ability to recover normal function once it is injured.

Animals↗
PubMed1981

Pathogenic effects of bullous pemphigoid autoantibodies on rabbit corneal epithelium.

Bullous pemphigoid (BP) is associated with circulating autoantibodies reactive with an antigen(s) of the basement membrane zone (BMZ) of skin and mucosae. The pathogenicity of these autoantibodies, although suspected, is unconfirmed. We have investigated the effects of BP autoantibodies on a closely related tissue, the corneal epithelium of the rabbit. IgG fractions from the sera of seven patients with BP were purified by (a) ammonium sulfate precipitation, (b) ion exchange chromatography, or (c) gel filtration. Control IgG was prepared by ion exchange chromatography of pooled normal human gamma globulins. 32 rabbits received corneal intrastromal injections of BP IgG fractions (50 microliter, 0.95-2.05 mg total dose) in one eye, and control IgG (50 microliter, 1.8 mg) in the contralateral cornea. 28 of 32 BP IgG injections produced corneal inflammatory lesions, 10 of which developed visible blisters. Histologically, lesions showed polymorphonuclear cells clustering along the BMZ, and subepithelial blister formation. Immunofluorescence showed in vivo bound IgG and C3 at the BMZ. The intensity of inflammation was dose dependent and correlated often with in vitro complement fixation titers of the fractions. None of 32 corneas injected with control IgG became inflamed. BP IgG fractions injected intradermally into the ear skin of rabbits failed to produce inflammation. This may be due to slow clearance of IgG in the cornea, and optimal binding by the corneal epithelium. The intracorneal injections of BP IgG reproduce the clinical, histological, and immunological features of BP. This study provides evidence that BP autoantibodies are pathogenic.

Animals↗