Search PubMed⌕ Search

Biomedical subjects

R E Smith

Publications and source records attributed to R E Smith.

At least 325 records · Page 18Linked to original sources

Contact lens-associated microbial keratitis.

During a 14-year period, 42 cases of microbial keratitis were associated with contact lens (CL) wear. Pseudomonas aeruginosa was isolated in 40% of the cases and Staphylococcus in 31%; Streptococcus pneumoniae, alpha-hemolytic Streptococcus, and Serratia marcescens were the next most commonly isolated pathogens. There was a single fungal corneal ulcer. Bandage CL use was associated with a high prevalence of infection with quasi-commensal organisms and with polymicrobial keratitis, a pattern of disease quite distinct from that induced by other types of CLs. Marked visual loss frequently occurred. There was a disturbing increase in the number of infections associated with extended-wear CLs (worn for either aphakia or myopia) over the last 18 months of the study.

Adolescent↗

An update of the indications for penetrating keratoplasty. 1979 through 1983.

We performed a retrospective analysis of the clinical and pathologic diagnoses of 497 corneal buttons that had been submitted to the Estelle Doheny Eye Pathology Laboratory, Los Angeles, during the five-year period 1979 through 1983. The leading indications, in order of decreasing frequency, were pseudophakic bullous keratopathy (17.5%), regrafts (15.1%), aphakic bullous keratopathy (10.9%), corneal trauma (9.3%), and Fuchs' endothelial dystrophy (9.1%). The emergence of pseudophakic bullous keratopathy as the most common cause for penetrating keratoplasty correlates well with the dramatic increase in the number of cataract extractions with intraocular lens implantations performed since the mid-1970s. Less frequent indications for penetrating keratoplasty included the following: corneal scars (6%); active ulcerative keratitis (7%); keratoconus (6%); keratitis secondary to virus (5%); non-Fuchs' corneal dystrophies (3%); congenital corneal opacities (3%); interstitial keratitis (2%); and chemical burns (1%).

Adolescent↗

Effect of extremely-low-frequency pulsed magnetic fields on the mitogenic response of peripheral blood mononuclear cells.

The effect of extremely-low-frequency pulsed magnetic fields (PMF) on the response of human peripheral blood mononuclear cells to mitogenic stimulation is reported. We investigated 25 healthy control subjects. Mitogen-stimulated mononuclear cells were exposed to PMF for 72 h and an inhibition of 3H-thymidine uptake was observed in all but one subject. The degree of inhibition of 3H-thymidine uptake was as much as 60%. There was no significant difference between the blastogenic responses of mononuclear cells exposed to PMF for 12 h and control cultures. This study establishes an inhibitory effect of PMF on an in vitro measure of immune function.

Adult↗

Persistent infection of rat insulinoma cells with Coxsackie B4 virus. Brief report.

Plaque purified Coxsackie B4 virus (CB4) caused a persistent infection of rat insulinoma (RIN) cells which lasted for the 70 day observation period. Infectious virus was produced and no cytopathic effect was observed. Indirect immunofluorescence and infectious center assays demonstrated that a majority of RIN cells were infected. Defective interfering particles were not demonstrated. Despite persistent infection, insulin synthesis by RIN cells was not altered.

Adenoma, Islet Cell↗

Microbial keratitis in children.

Forty-seven eyes with microbial keratitis occurring in 44 children under 16 years of age were studied. Under the age of three, 92% of the infections involved Pseudomonas aeruginosa and/or various streptococcal species; later in childhood the typical adult pattern of infection was more common. Overwhelming systemic infections, malignant disease with orbital involvement and congenital ocular adnexal disease were important predisposing factors in the infant years; trauma and acquired external eye disease became increasingly important in mid-childhood. Surgery was necessary in 28% of the eyes. Frequent tearing and lack of patient cooperation preclude reliance on topical antibiotic therapy alone. Despite the difficulties, the mainstay of management involves daily biomicroscopic evaluation and regular subconjunctival antibiotic injections. The logistical problems of achieving these aims are discussed.

Age Factors↗

Occupational asthma in a hairdressing salon.

Occupational asthma among hairdressers has been recognised for some years and cases of work related asthma due to hair bleaches containing persulphates and hair dyes have been reported. The extent of the disease among hairdressers remains unknown. An investigation was carried out on an entire hairdressing salon, which specialised in hair bleaching and colouring and which employed 23 staff. On the basis of history and specific and non-specific bronchial provocation testing, four out of 23 staff were found to have occupational asthma due to the persulphate salts contained in hair bleaches. Only one of these had a positive skinprick test response to persulphate salts. Tests for non-specific bronchial reactivity to histamine in this work force were more sensitive for the diagnosis of asthma than simple lung function tests or recordings of peak flow rates performed four times daily for three weeks. The response to these agents was studied in greater detail by specific bronchial provocation tests in 14 members of the salon as well as one hairdresser from elsewhere with occupational asthma, three individuals with non-occupational asthma, and four normal subjects. Only those with a history of work related asthma and bronchial hyperreactivity responded positively, confirming that the response to bleach powders was specific. Studies of pulmonary mechanics after challenge showed that the response arose from changes in airway calibre not lung volumes. Measurement of neutrophil chemotactic activity after challenge showed significant rises in those affected, suggesting that mast cells may play a part in the pathogenesis of occupational asthma due to persulphates.

Adolescent↗

A new fluorescent detection system for identifying variant hemoglobins after gel electrophoresis using immunobinding with monoclonal antibodies.

This paper describes a low-resolution system for identifying variant hemoglobins with great sensitivity and specificity. After electrophoresis of the hemoglobin sample in a gel, fixation is used to entrap the hemoglobin. The gel is dried, incubated with a monoclonal antibody against the desired hemoglobin, then incubated with a second antibody against the first antibody which is conjugated with the enzyme beta-d-galactosidase. An enzyme overlay membrane containing a fluorogenic substrate is then placed on the gel surface, incubated, and removed, yielding an immunofluorescent print. The entire procedure takes only two hours, and by virtue of fluorescent detection gives sharper band resolution and greater sensitivity than conventional dye methods. The system clearly distinguishes SS sickle-cell hemoglobin from heterozygous and "S-like" hemoglobins. The technique therefore holds promise as a powerful probe for allelic variants.

Antibodies, Monoclonal↗

Immunofluorescent detection of Histoplasma capsulatum in primate experimental ocular histoplasmosis.

We have developed a polyclonal anti-Histoplasma capsulatum antibody to detect H. capsulatum antigens in ocular tissue. Antibodies were specific for H. capsulatum as determined by enzyme linked immunosorbent assay and immunoprecipitation. A total of 21 choroidal histoplasmic lesions in 4 primate eyes (Macaca speciosa and Macaca mulatta), taken at various times from 14 to 60 days after the internal carotid artery injection of yeast phase organisms, were evaluated. Using an indirect immunofluorescent technique, these antibodies stained yeast phase organisms within acute choroidal lesions at 14 days after infection. By 60 days intact organisms were no longer detected; occasional cells, however, contained intracellular inclusions that stained with these antibodies. Although yeast phase organisms are rapidly cleared from the primate choroid, these data indicate that residual H. capsulatum antigens may remain in choroidal lesions after the acute infectious stage. These findings are consistent with the hypothesis that H. capsulatum antigens play a role in the immunologic reactivation of atrophic choroidal scars in ocular histoplasmosis.

Animals↗

Pharmacologic probes of neurotransmitter systems in tardive dyskinesia: implications for clinical management.

Despite the plethora of clinical drug trials in tardive dyskinesia, few consistent findings have emerged. One possible reason for this is that there have been no serious attempts to define the role of major neurotransmitter systems (dopamine, norepinephrine, acetylcholine, serotonin, GABA) in one specific population of tardive dyskinesia patients. This study reports a series of five controlled drug trials in a population of patients with persistent tardive dyskinesia; each drug probed one of four neurotransmitter systems. The intra- and interpatient responses are analyzed and the implications of the pharmacologic response profiles for the clinical management of tardive dyskinesia are discussed.

5-Hydroxytryptophan↗

Pars planitis.

The records on thirty-three patients (58 eyes) with the diagnosis of pars planitis were reviewed. The patients were divided into 4 groups: Group 1 had bilateral vitreous cells and pars plana 'snowbank' formation (13 patients, 26 eyes), Group 2 had bilateral vitreous cells and 'snowbank' formation in one eye only (8 patients, 16 eyes), Group 3 had vitreous cells and 'snowbank' formation in one eye only (8 patients, 8 eyes), and Group 4 had bilateral vitreous cells without 'snowbank' formation (4 patients, 8 eyes). Frequent findings and complications were tabulated; cystoid macular oedema was the most common cause of decreased vision. Although pars plana 'snowbank' exudates are usually present in pars planitis, they may not be necessary to make the diagnosis. An approach to therapy is outlined.

Adolescent↗

Anaerobic bacterial endophthalmitis in the rabbit.

Anaerobic bacterial endophthalmitis was studied in rabbits following intravitreal injection of live Fusobacterium necrophorum. Clinical response, bacterial recovery, and histopathology were studied. An inoculum of approximately 50 organisms produced endophthalmitis in 59% of injected eyes, while 1000 or more organisms produced endophthalmitis in 100% of injected eyes. The course and severity of disease seemed to be independent of the concentration of bacteria above a minimal inoculum size. Affected eyes showed progressive endophthalmitis. Histopathologic changes corresponded to the clinical gradation of endophthalmitis, including progressive retinal necrosis.

Animals↗

Hand-mirror-cell variant of B-cell lymphoma with hypercalcemia.

The first (to my knowledge) case of confirmed hand-mirror cell (HMC) non-Hodgkin's lymphoma is described in a 56-year-old white woman. Surface-marker analysis indicated that the cells were B cells with surface IgM (lambda). The HMC phenomenon was considered to be real since it was seen on both Wright-Giemsa and supravital stains. In addition, this patient had uncontrollable hypercalcemia and unusual bone-scan findings. The significance of HMC and hypercalcemia in non-Hodgkin's lymphoma is discussed.

B-Lymphocytes↗

A case of Dipylidium caninum in Baton Rouge, Louisiana.

The relevant literature concerning human dipylidiasis has been reviewed with specific reference to the association of children and their pet dog and cats. A specific case is recounted which is considered to be typical of the condition as encountered by pediatricians and general practitioners.

Animals↗

Subretinal neovascularization after experimental ocular histoplasmosis in a subhuman primate.

Subretinal neovascularization was demonstrated in a subhuman primate eye (Macaca speciosa) one year after the internal carotid injection of yeast-phase Histoplasma capsulatum. In this animal model of ocular histoplasmosis, initial injection of viable H. capsulatum results in the development of self-limiting acute multifocal choroiditis. Acute lesions resolve within six months, forming chorioretinal scars that are clinically similar to human histo spots. Detailed ultrastructural study of a peripapillary scar 30 months after the injection showed the presence of subretinal neovascularization located between Bruch's membrane and degenerated retinal inner segments. These vessels appeared to be continuous, had tight junctional complexes, and a well-developed basal lamina with occasional pericytes. Failure of fluorescein angiography to demonstrate the presence of this neovascular net may be explained by the presence of tight junctions within the subretinal capillaries.

Animals↗