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Biomedical subjects

G Stevens

Publications and source records attributed to G Stevens.

At least 91 records · Page 5Linked to original sources
PubMed1989

An outbreak of Mycobacterium bovis infection in fallow deer (Dama dama).

In an outbreak of Mycobacterium bovis infection in fallow deer in South Australia, 3 herds related by recent movement of deer were infected. From these 3 infected herds, 47 of 51 animals were tuberculosis at necropsy. A range of lesions was seen most of which differed from classical bovine tuberculosis in that pus was a white liquid, fibrous encapsulation was not marked and calcification was rare. Histopathology was of classical tuberculosis. M. bovis was cultured from lesions and M. avium-intracellulare was cultured from one deer with no visible lesions. The source of M. bovis infection has not been determined.

Animals↗
PubMed1989

Report from the American Nurses' Association council on psychiatric and mental health nursing.

Society has demonstrated a major need for expanded gerontological and geropsychiatric nursing services. Current needs have not yet been met and the call for service will increase throughout the balance of this century and beyond. Social responsiveness demands that nurses: (1) formally establish their clinical authority in care of the aged; (2) lobby for public policy which enables the provider professional to control the practice environment, rather than be controlled by it; (3) improve the educational preparation of nurses to care for the aged; and (4) expand the professions' scientific and research base in this area. The national professional organization of registered nurses, the American Nurses' Association, provides leadership to influence the course of nursing as it continues to provide vital services in a dramatically changing environment.

Aged↗
PubMed1989

Clinical audit--occurrence screening for QA.

The white paper says that within the next two years the Government would like to see all doctors taking part in medical audit. There are various ways in which an audit might be undertaken, and recently a pilot study was carried out in the Brighton district of a system which has been used effectively in the USA and Australia.

England↗
PubMed1988

Essential iris atrophy. A clinical, immunohistologic, and electron microscopic study in an enucleated eye.

A 29-year-old woman had unilateral essential iris atrophy, corneal endothelial changes, and absolute glaucoma. The enucleated eye was examined by routine light microscopy. Separate portions of unfixed fresh frozen cornea were sectioned and reacted with monoclonal antibodies against keratins, vimentin, and inflammatory cell markers. Stains for filamentous actin (f-actin) were performed using the 7-nitro-benz-2-oxa-1,3-diazolylphallacidin (NBD phallacidin) probe. In addition, portions of cornea and iris were examined by scanning and transmission electron microscopy. Immunocytochemical stains with anti-keratin antibodies showed reactivity only in the corneal epithelium of the patient and normal control. Immunoreactivity with anti-vimentin antibodies was observed in corneal endothelium and keratocytes of the patient and control, but was negative in the epithelium. Staining for f-actin appeared more pronounced in the corneal endothelium of the patient. Scanning electron microscopy of the corneal endothelium showed irregularity in cell size and shape and filopodial processes characteristic of migrating cells. Transmission electron microscopy disclosed abnormalities of Descemet's membrane and endothelium with a posterior collagenous layer. The corneal endothelium displayed normal junctional complexes without desmosomal junctions or increased microvillus projections. Increased 10-nm cytoplasmic filaments were noted consistent with the expression of vimentin. Occasional chronic inflammatory cells perturbed the corneal endothelium and were detected within the endothelial layer. Alterations in the endothelium and Descemet's membrane suggest the acquired nature of this disease.

Actins↗
PubMed1987

Iris lymphocytic infiltration in patients with clinically quiescent uveitis.

Iridectomy specimens from 16 patients with clinically quiet chronic uveitis were analyzed by immunoperoxidase staining and compared to control iridectomy specimens from 11 non-uveitic patients. Nine of 16 uveitis specimens and none of the control specimens demonstrated a lymphocytic infiltrate consisting of interleukin-2 receptor-negative T helper and suppressor cells (P less than .003). Class II antigens were detected in the iris stroma in all uveitis specimens and six of the controls (P less than .006). Despite a quiescent clinical state, patients with chronic uveitis have increased expression of class II antigens in uveal tissue and have significant uveal infiltration of T helper and suppressor cells. These findings in a variety of types of uveitis give additional support for the importance of delayed type hypersensitivity mechanisms in human uveitic disease.

Adolescent↗
PubMed1987

Immunopathology and electron microscopy of Acanthamoeba keratitis.

In order to evaluate the local cellular immune response to Acanthamoeba infection we performed immunohistochemical examinations of the corneal buttons of two patients with Acanthamoeba keratitis. We found that the corneal stroma was infiltrated with polymorphonuclear leukocytes and HLA-DR positive macrophages that appeared to be stromal keratocytes by light microscopy. Despite the presence of chronic inflammation in both patients, no stromal lymphocytes were seen in one patient and a sparse lymphocytic infiltrate was seen in the other patient. Electron microscopy confirmed the presence of macrophages, neutrophils, and Acanthamoeba organisms in these two patients.

Adult↗
PubMed1987

Narrow polarized components in the OH 1612-MHz maser emission from supergiant OH-IR sources.

High-resolution OH 1612-MHz spectra are presented of the supergiant OH-IR sources VY CMa, VX Sgr, IRC 10420 and NML Cyg. The spectra have a resolution of 300 Hz. Narrow components in the spectra have linewidths as small as 550 Hz (0.1 km s-1) but there is no evidence for components narrower than this. These results are in accord with present understanding of maser line-narrowing and of the physical conditions in the OH maser regions. Many of the narrow components have an appreciable degree of circular polarization which is not apparent at the lower frequency resolutions usually employed. The circular polarization indicates the presence of magnetic fields of approximately 1 mG in the circumstellar envelopes, at distances of approximately 3x10(16) cm from the central stars. These fields are strong enough to influence the outflow from the stars, and may help to explain some of the asymmetries which are seen in their circumstellar envelopes.

Astronomical Phenomena↗
PubMed1986

Treatment of cytomegalovirus retinitis with dihydroxy propoxymethyl guanine.

Eight patients with cytomegalovirus retinitis in one or both eyes were treated with 9-(1,3 dihydroxy 2-propoxymethyl) guanine. Of the 14 eyes with retinitis, eight demonstrated more than 90% resolution, four had partial improvement, one failed to respond, and one could not be evaluated. Two of the eight patients had chemotherapy-induced immunosuppression and had ocular remissions for at least several months. The remaining six patients had AIDS or probable AIDS and relapsed in five weeks or less after discontinuation of therapy. Dihydroxy propoxymethyl guanine appears to be effective biologically in treating human cytomegalovirus retinitis without the development of unacceptable side effects but a single course of therapy is not capable of eradicating the virus.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Immunohistochemistry and electron microscopy of cyclitic membrane. Report of a case.

An immunohistochemical study using various antibodies directed against antigens of inflammatory cells, neurons, and Müller cells, interstitial collagens (types I and III), basement membrane collagens (types IV and V), and basement membrane glycoproteins (laminin and fibronectin) was performed to characterize the components of two cyclitic membranes (in an enucleated eye and a surgical specimen) from a 15-year-old patient with an eight-year history of chronic bilateral uveitis. When specimens were obtained, no inflammation was seen clinically. Correlative light and electron microscopic examinations were also performed on one specimen. The preponderant cells in the cyclitic membrane were glial cells. The preponderant extracellular tissue within the cyclitic membrane consisted of basement membrane components. These observations suggest that cyclitic membranes could be formed mainly by the extension of proliferative glial elements from the retina, with a minor component derived from fibroblasts.

Adolescent↗
PubMed1986

Sympathetic ophthalmia. Immunopathological findings.

Ocular tissue from six patients with a clinical diagnosis of sympathetic ophthalmia (SO) was examined using immunohistochemical techniques. All patients presented with a history of bilateral panuveitis after penetrating ocular injury or multiple intraocular surgeries and clinical features of SO. In four cases, classic histopathological features of SO were observed, including granulomatous uveal tract infiltration and subretinal pigment epithelium (RPE) collections of inflammatory cells (Dalen-Fuchs nodules). Bone marrow derived monocytes were the major cellular components in these granulomas. In two cases, histopathology failed to demonstrate typical Dalen-Fuchs nodules or granulomas in the choroid. However, the choroidal infiltrates were composed primarily of T-helper and B lymphocytes, without macrophages or epithelioid cells. The eyes examined in this report indicate that a varied spectrum of immunopathological and histopathological findings may occur in clinically diagnosed SO.

Adult↗
PubMed1986

Effect of 9-(1,3-dihydroxy-2-propoxymethyl) guanine on serious cytomegalovirus disease in eight immunosuppressed homosexual men.

Eight immunosuppressed homosexual men with cytomegalovirus viremia--seven with serious bilateral retinitis, one with colitis in addition to retinitis, and one with pneumonitis only--were treated with a new acyclovir derivative, 9-(1,3-dihydroxy-2-propoxymethyl) guanine, which has excellent in-vitro activity against cytomegalovirus. All patients had virologic and clinical improvement, but substantial leukopenia developed in three patients. Both clinical relapses and viral relapses occurred frequently, usually within 30 days after cessation of treatment. 9-(1,3-Dihydroxy-2-propoxymethyl) guanine represents the first clinically and virologically effective agent for the treatment of cytomegalovirus disease, but more effective and less toxic therapeutic regimens for both acute and chronic use must be developed.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Factor analyses of two 'attitude toward gender role' questionnaire.

Two questionnaires which purport to assess attitudes toward gender role, the Maferr Inventory of Feminine Values and the Sex Stereotype Questionnaire, were submitted to a factor analysis. While each analysis of the five response set items yielded interpretable factors with unequivocal item scores, the obtained factors are not consistent with the a priori assignment of items to "groupings" suggested by the manuals for these instruments. The implications of using questionnaires with questionable psychometric properties is discussed.

Journal Article↗