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Biomedical subjects

W R Freeman

Publications and source records attributed to W R Freeman.

At least 199 records · Page 11Linked to original sources
PubMed1988

Intraocular pressure response after pneumatic retinopexy.

We measured intraocular pressure over a five-day period in ten consecutive patients undergoing pneumatic retinopexy to determine the effect of an expanding gas bubble. During treatment, all eyes received 0.3 ml perfluoropropane gas. All eyes had an immediate rise in intraocular pressure, which in four eyes was associated with absence of central retinal artery perfusion for three minutes. Once intraocular pressure fell toward baseline (30 to 60 minutes after gas injection), we did not find a high intraocular pressure during the subsequent five-day period. We conclude that intraocular pressure-reducing medication is not routinely indicated in these eyes.

Cryosurgery↗
PubMed1987

Prevalence, pathophysiology, and treatment of rhegmatogenous retinal detachment in treated cytomegalovirus retinitis.

Seventeen patients with the acquired immune deficiency syndrome and cytomegalovirus retinitis were treated with the antiviral drug ganciclovir (9-[1,3-dihydroxy-2-propoxy-methyl]-guanine, DHPG). Eight eyes of five patients developed rhegmatogenous retinal detachment after initiation of treatment. Multiple breaks in areas of peripheral, healed, atrophic retina accounted for the detachments. All seven eyes that underwent surgery had extensive retinal detachments that were reattached with vitrectomy and silicone oil. Retinotomy and retinal tacks were necessary in two cases that were complicated by severe proliferative vitreoretinopathy. In the fellow eye of one patient, laser treatment was used prophylactically to wall off a peripheral patch of healed retinitis. Endoretinal biopsies and culture were taken in five eyes; evidence of persistent cytomegalovirus was seen in two cases despite concurrent and clinically effective antiviral therapy.

AIDS-Related Complex↗
PubMed1987

Cytomegalovirus retinitis as the initial manifestation of the acquired immune deficiency syndrome.

We studied eight patients in whom cytomegalovirus retinitis was an initial manifestation of AIDS. Six of these patients had cytomegalovirus retinitis alone at the time of diagnosis and two patients had simultaneous cytomegalovirus retinitis with other AIDS associated diseases (Kaposi's sarcoma in one patient and cytomegalovirus colitis in one patient). Treatment with ganciclovir (dihydroxy propoxymethyl guanine), a new antiviral medication related to acyclovir, resulted in regression of retinitis in all five patients treated with this drug. Our study shows that cytomegalovirus retinitis may be the initial manifestation of AIDS and that ganciclovir is a clinically effective antiviral agent for cytomegalovirus.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Echographic localization of corticosteroids after periocular injection.

The location of repository corticosteroid after subtenon injection was determined in 24 patients with macular edema associated with uveitis or anterior segment surgery. Standardized A-scan and B-scan echography were performed immediately before and after each injection. Localization was compared after subtenon injection in either the superior or inferior temporal quadrants. Echography showed that corticosteroid was deposited within the subtenon space over the macula in 11 of 24 cases. The therapeutic response manifested by improvement in macular function may be related to the proximity of the corticosteroid to the macular area. Lack of therapeutic response to repository corticosteroids may be because of placement at a site relatively far from the target zone.

Adrenal Cortex Hormones↗
PubMed1987

Chemotactic activity in aqueous humor from patients with anterior uveitis.

Anterior uveitis, inflammation of the iris or ciliary body of the eye, may be associated with a variety of systemic diseases. Although a leukocytic infiltrate is characteristic of anterior uveitis, few studies have sought to detect factors in aqueous humor that could attract neutrophils or monocytes into the anterior chamber. Using modified Boyden chambers, we found that a 5% concentration of aqueous humor from patients with anterior uveal inflammation induced monocyte movement comparable to optimal or near-optimal concentrations of C (complement)5a or platelet-derived growth factor. Aqueous humor from patients with anterior uveitis induced significantly more monocyte migration than did aqueous humor from two sets of controls (either patients undergoing cataract extraction or patients with posterior uveitis). "Checkerboard" or gradient analysis indicated that a majority of inflammatory disease samples induced monocyte chemotaxis (directed migration) while the control aqueous humor consistently induced chemokinesis (stimulated random migration) (P less than 0.02). Despite their ability to induce monocyte migration, samples tended to induce minimal neutrophil migration with the exception of aqueous humor that was obtained from one patient with acute anterior disease. This sample induced marked chemokinesis. Identification of chemotactic activity may clarify the pathogenesis of uveitis and the characterization of leukocyte migration factors in aqueous humor may help define subsets of anterior uveal inflammation.

Aqueous Humor↗
PubMed1987

Cytomegalovirus retinitis and response to therapy with ganciclovir.

A 15-month prospective study of 109 patients with the acquired immune deficiency syndrome (AIDS) or AIDS-related complex (ARC) was conducted. Cytomegalovirus (CMV) retinitis developed in 18 of these patients; they were treated with ganciclovir. Five other patients with CMV retinitis who were not part of the prospective study were also treated with ganciclovir. CMV retinitis frequently involved the peripheral retina. All 23 patients treated with ganciclovir showed clinical regression of retinitis, although breakthrough recurrence of CMV retinitis occurred in seven patients (30.4%) while on maintenance therapy with ganciclovir. During treatment, neutropenia (less than 1000 leukocytes/mm3) developed in three patients (13%). Ganciclovir is an effective means of therapy for CMV retinitis, but it must be given chronically to prevent reactivation. Breakthrough recurrences while on maintenance therapy are not uncommon, but can be successfully treated with more aggressive treatment with ganciclovir. In addition, the prognosis for survival of AIDS patients being treated with ganciclovir is improved when compared with that of untreated patients.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Demonstration of herpes group virus in acute retinal necrosis syndrome.

Tissue for pathologic examination was obtained from three cases of acute retinal necrosis syndrome. Virus particles belonging to the herpesvirus family were demonstrated in retinal biopsies from two patients, one of whom was immunosuppressed. Despite removal of large biopsy specimens, the retina has remained attached for 20 months postoperatively in one case and for three months in the other. In a third patient with acquired immune deficiency syndrome, the clinical course and postmortem immunopathology were suggestive of a herpes simplex virus infection, initially affecting the retina and subsequently the optic nerves, chiasm, tracts, and central nervous system. These cases illustrate that the virus associated with the acute retinal necrosis syndrome is easily demonstrable using vitrectomy and endoretinal biopsy in the acute phase of the disease, but may be difficult to demonstrate in chronically detached atrophic retinas.

Acute Disease↗
PubMed1986

Lymphocyte subpopulations in uveitis.

We have used a fluorescence-activated cell sorter to study the lymphocyte subpopulations in the intraocular fluids and peripheral blood of 27 patients with uveitis. T lymphocytes predominated in intraocular fluids. A wide variation in the ratio of Leu 3a-positive (helper) cells to Leu 2a-positive (suppressor) cells was found. No correlation was seen between the specific lymphocyte subpopulations and the clinical uveitis activity or steroid treatment. A statistically significant correlation was found between T-cell subsets present in aqueous humor and peripheral blood. Many lymphocytes seem to be present in intraocular fluids secondary to a breakdown of the blood-ocular barrier.

Adrenal Cortex Hormones↗
PubMed1984

Microtechniques for flow cytometric analysis of aqueous humor lymphocytes.

Flow cytometric analysis of monoclonal antibody labelled lymphocytes is an important tool in understanding the immune response. Microtechniques were developed to analyze lymphocytes in small amounts of ocular fluids. Optimal labelling volumes and concentrations for Leu 2a, Leu 3a, Leu 4 and Leu M3 antibodies were determined. The ability to label and reproducibly analyze cell samples with as few as 1000 cells is demonstrated.

Antibodies, Monoclonal↗
PubMed1984

A prospective study of the ophthalmologic findings in the acquired immune deficiency syndrome.

A prospective evaluation of ophthalmologic findings in 26 patients (25 men and one woman) with the acquired immune deficiency syndrome disclosed that 19 patients had significant ocular abnormalities. These included isolated retinal hemorrhages, cotton-wool spots, cytomegalovirus retinitis, acute retinal necrosis, cranial nerve palsies, and orbital Kaposi's sarcoma. Hemorrhages and cotton-wool spots appeared and disappeared spontaneously. Cytomegalovirus retinitis and acute retinal necrosis were progressive and destructive. The fundus findings did not correlate with the patient's general clinical status.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Cytomegalovirus retinitis: a manifestation of the acquired immune deficiency syndrome (AIDS).

Two homosexual males with the "gay bowel syndrome' experienced an acute unilateral loss of vision. Both patients had white intraretinal lesions, which became confluent. One of the cases had a depressed cell-mediated immunity; both patients ultimately died after a prolonged illness. In one patient cytomegalovirus was cultured from a vitreous biopsy. Autopsy revealed disseminated cytomegalovirus in both patients. Widespread retinal necrosis was evident, with typical nuclear and cytoplasmic inclusions of cytomegalovirus. Electron microscopy showed herpes virus, while immunoperoxidase techniques showed cytomegalovirus. The altered cell-mediated response present in homosexual patients may be responsible for the clinical syndromes of Kaposi's sarcoma and opportunistic infection by Pneumocystis carinii, herpes simplex, or cytomegalovirus.

Acquired Immunodeficiency Syndrome↗
PubMed1983

A graphical analysis of the interrelationships among waterborne asbestos, digestive system cancer and population density.

Five statistical procedures were used to partial the correlation between waterborne asbestos and digestive site cancer for the putative effects of population density. These include: analysis based on a data subset with roughly homogeneous population density; standard residual analysis (partial correlation); conditional probability integral transformation; analysis based upon ranked data, and use of logarithmic transformation. Nonparametric regression graphical techniques are applied to examine the nature or shape of the asbestos-cancer dose-response curve. Evidence is presented that suggests that there is considerable difference between analyses involving nonhigh-density tracts and non-San Francisco tracts. Evidence is also presented that the modal-type nonparametric regression curve forks or bifurcates when adjustment is made for population density.

Asbestos↗
PubMed1983

Iridoschisis and the corneal endothelium.

Iridoschisis has been known as a rare entity for the past 60 years, since its first description by Schmitt. It has been reported most frequently in eyes with a history of trauma or one of the glaucomas. While freely floating fibers of disrupted iris mesenchyma may be seen to brush against the corneal endothelium in many patients, there has never been a report of corneal compromise secondary to iridoschisis. A patient with bilateral glaucoma is described. Iridoschisis was present in one eye, and specular microscopy revealed a marked decrease in cell density (600 cells per square millimeter) directly over the split iris fibers. A high degree of polymegethism was also present over the involved sector of iris. Cell counts and morphological findings elsewhere in the cornea were normal for the patient's age. Iridoschisis may be a hitherto unrecognized cause of endothelial decompensation. In selected cases, prophylactic surgical iridectomy should be considered in order to remove the disrupted iris fibers that may play a role in corneal changes.

Aged↗
PubMed1981

Effect of informed consent and educational background on patient knowledge, anxiety, and subjective responses to cardiac catheterization.

Thirty-four patients undergoing elective cardiac catheterization were followed linearly with three questionnaires during their hospitalization to study some of the effects of informed consent. Patients learn about catheterization from the informed consent session conducted by a cardiology fellow. Several areas of knowledge deficiency were found. The emotional experience of hospitalization and the amount of knowledge about catheterization determined at the end of hospital stay is shown to be dependent on the educational level of the patient. Several recommendations are made for the conduct of the informed consent sessions to improve the knowledge of the less educated.

Adult↗
PubMed1981

Verapamil therapy in variant angina pectoris refractory to nitrates.

Conventional therapy including nitrates, beta blockers, and surgical bypass has proved to be generally unsatisfactory in patients with variant angina of suspected vasospastic etiology. Recent evidence regarding the role of calcium in the pathogenesis of vascular smooth muscle spasm prompted an open study of the clinical effects of verapamil in seven patients with recurrent rest angina refractory to nitrates. The patients studied met strict clinical ECG and angiographic criteria for vasospastic angina. All patients had rapid (within 24 hours) and complete (without recurrence of symptoms) chronic response to oral verapamil therapy. The pharmacology of verapamil relating to the pathogenesis of vasospastic angina is delineated and guidelines for the clinical application of the agent are presented.

Adult↗
PubMedDate not supplied

In situ nucleic acid hybridization.

Nucleic acid hybridization is a recently developed laboratory technique that allows identification of the genetic material in tissue specimens. The role of the nucleic acids DNA and RNA in cellular function and disease is reviewed, followed by discussion of nucleic acid detection techniques. Earlier methods used to detect nucleic acids were slow and time-consuming. Current in situ detection techniques allow rapid characterization of pathogenic organisms in tissue sections and localization of the pathologic genetic material to specific cellular regions. This technology has been useful in the understanding of viral ocular diseases including herpes keratitis and cytomegalovirus retinitis and also has great potential in the understanding of the pathogenesis of human cancers, genetic disorders and endocrine and immunologic diseases.

DNA↗