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Biomedical subjects

S M Walsh

Publications and source records attributed to S M Walsh.

At least 37 records · Page 2Linked to original sources
PubMed1993

The time course of irradiation changes in proton beam-treated uveal melanomas.

BACKGROUND: Although histopathologic changes in uveal melanomas treated by irradiation have been well characterized, the timing of these effects after irradiation has not been previously evaluated. METHODS: The series consisted of a total of 92 eyes with uveal melanoma, enucleated at various intervals after proton irradiation (range, 1 month to 8 years) due to complications (n = 66) or tumor growth (n = 22), or at autopsy (n = 4). Study slides were read, using a standard protocol, by two pathologists masked to the timing of the enucleation after irradiation and the reason for the surgery. RESULTS: The prevalence of inflammation decreased whereas fibrosis increased with time from 15% of cases enucleated within 12 months (early cases) to 61% of those enucleated more than 30 months (late cases) after irradiation (P for trend = 0.0005). Tumor necrosis and blood vessel damage occurred early, and the prevalence of these changes was constant over time. Excluding tumors with evidence of growth after irradiation, mitotic figures became progressively less common as the interval between irradiation and enucleation increased (P for trend = 0.015); no mitotic figures were present in 40 high-power fields more than 30 months after irradiation. CONCLUSION: Histopathologic changes in irradiated melanomas vary according to the time elapsed since irradiation. Inflammation decreases with time whereas fibrosis becomes more prevalent with time after irradiation. Among controlled tumors, mitotic figures appear only in recently irradiated tumors.

Adult↗
PubMed1993

An evaluation of the influence of reproductive factors on the risk of metastases from uveal melanoma.

BACKGROUND: There is a paucity of data concerning the possible role played by hormonal factors in the risk of metastases from intraocular melanomas. METHODS: The authors studied the influence of post-diagnosis pregnancy and oral contraceptive use in a group of women of reproductive age (45 or younger) who were treated for uveal melanoma by proton beam irradiation. A baseline reproductive history had been collected before irradiation for all women, and interim reproductive data were collected by mailed questionnaire. RESULTS: In this age group, the overall rate of metastasis among women was similar to that of men treated during the same interval (adjusted rate ratio: 1.28; 95% confidence interval: 0.62-2.67). A total of 24 full-term pregnancies were reported among the 139 women still menstruating at diagnosis. Twenty-three women reported regular oral contraceptive use. Metastases developed in 15 of the 139 women. Compared with other women in the series, rates of metastases were not higher among the women who reported pregnancies (P = 0.932) or oral contraceptive use (P = 0.424) after diagnosis. CONCLUSION: Although based on limited numbers, results suggest that the hormonal environment has no appreciable influence on risk of metastases in younger women with uveal melanoma.

Adolescent↗
PubMed1993

Future images: an art intervention with suicidal adolescents.

In this study, the effectiveness of an art future-image intervention (AFI) designed to increase self-esteem, improve future time perspective, and decrease depression in hospitalized suicidal adolescents was tested. A pretest-posttest time series design was used with two groups, an experimental group and an attention placebo group. The experimental group, although hospitalized for a shorter length of time (p = .08), showed greater positive changes than the placebo group. Both groups improved on all measures during and after hospitalization. Experimental participant enthusiasm, shorter hospitalization, and positive comments at follow-up warrant continued testing and refinement of the AFI.

Adolescent↗
PubMed1993

Orientation intervention for parents of adolescents after psychiatric hospitalization.

An orientation class has been devised to address the fears, uncertainties, and vulnerabilities of parents admitting their children to an adolescent psychiatric unit. This orientation class offers support and information to parents of adolescents admitted to Charter Rivers Hospital, a private psychiatric inpatient facility in Columbia, South Carolina, and is held during the first week of the adolescent's hospitalization.

Adaptation, Psychological↗
PubMed1992

Histopathology of proton beam-irradiated vs enucleated uveal melanomas.

The histopathology of eyes with uveal melanoma was compared in a masked fashion in 47 eyes whose primary treatment was enucleation and a matched series of 47 eyes enucleated after proton beam irradiation. Irradiated tumors were more likely to show signs of necrosis (P less than .001) and fibrosis (P = .005) and to have balloon cells present (P = .002). In the irradiated group, mitotic figures were fewer in 40 high-power fields (P = .020), and the prevalence of tumor blood vessel damage (P less than .001) was higher. Changes in the retina were more common in the irradiated series, but damage was usually overlying or in close proximity to the tumor. Based on characteristic changes, the pathologist distinguished irradiated from nonirradiated eyes in 85% of the cases. These findings suggest that irradiation damages tumor cells and blood vessels, and alters the tumor's capacity for cellular reproduction.

Adult↗
PubMed1992

Radiation maculopathy after proton beam irradiation for choroidal melanoma.

PURPOSE: Radiation maculopathy is a microangiopathy of the retina, which is often observed after irradiation of the eye. To quantitatively determine the frequency of anatomic and functional features of this condition, the authors reviewed a large series of patients with choroidal melanomas who were treated by proton beam irradiation. METHODS: Color photographs and/or fluorescein angiograms of 218 patients with paramacular choroidal melanomas were graded by two independent masked readers to determine the frequency of the various lesions of radiation maculopathy. RESULTS: Overall, 194 (89%) of the 218 patients in this study developed some degree of radiation maculopathy. The earliest and most common finding was macular edema, which was observed in 87% of patients, overall, by the end of year 3. Microvascular changes (microaneurysms and/or telangiectasia), intraretinal hemorrhages, and capillary nonperfusion were noted in 76%, 70%, and 64% of eyes, respectively, by the end of postirradiation year 3. Visual acuity was retained at 20/200 or better in 90% of eyes 1 year after irradiation and in 67% of eyes 3 years after treatment. CONCLUSION: Radiation maculopathy is common after proton beam irradiation of paramacular choroidal melanomas. However, ambulatory vision is preserved in many eyes.

Adolescent↗
PubMed1992

Intraocular recurrence of uveal melanoma after proton beam irradiation.

The authors evaluated tumor recurrence as an end point in 1077 uveal melanoma patients treated by proton beam irradiation between 1975 and 1987, with a mean follow-up of 4.0 years. Twenty tumors (1.9%) exhibited definitive growth between 4 months and 66 months after irradiation (median, 19 months): 10 were marginal recurrences, 5 were ring melanomas, 3 were uncontrolled tumors, and 2 were extrascleral extensions. Ten of these eyes were enucleated without further intervention, 2 patients died of metastases soon after the growth was detected, and 8 patients had further conservative therapy. In 5 other patients, tumor growth was suspected but unconfirmed and the eye was enucleated elsewhere; the 5-year probability of local tumor control based on 25 recurrences was 97% +/- 1%. There was a nonsignificant increase in the rate of metastases among patients with documented tumor recurrence (adjusted relative risk, 1.5; 95% confidence interval, 0.66 to 3.4). Results suggest that recurrence of uveal melanomas treated by proton beam therapy is uncommon, but that treatment failure may increase risk of death from metastasis.

Adolescent↗
PubMed1992

Smoking and the risk of early metastases from uveal melanoma.

Smoking is suspected of altering host immunity and may therefore hasten the development of metastases among cancer patients. The authors followed 946 patients with melanomas of the choroid and/or ciliary body who had been treated with proton beam irradiation and who had provided a smoking history during their evaluation before treatment. After a mean follow-up of 33 months, 98 patients were diagnosed with metastatic disease. Metastasis-free survival rates 3 years after irradiation were similar in association with never, past, and current cigarette smoking (86%, 89%, and 90%, respectively; P = 0.90). Rates also were similar with increasing pack-years of exposure and when the product smoked was cigarettes versus pipes or cigars only. Estimates for smoking effects were unchanged after adjusting for established prognostic factors for metastases. Results suggest that smoking does not alter the risk of metastases during the first few years after irradiation of choroidal melanomas.

Adolescent↗
PubMed1992

Visiting critically ill adults: strategies for practice.

Visitation and proximity needs are consistently rated as very important by families of critically ill patients. This article reviews the literature on the proximity needs of families, presents nursing interventions to meet them, and suggests a plan for future research in this area.

Family↗
PubMed1991

Survival of patients with metastases from uveal melanoma.

The authors evaluated a series of 145 consecutive patients with metastases from uveal melanoma, after proton beam irradiation, to assess the effect of early diagnosis and treatment for metastases on survival. Metastases were diagnosed between 7 weeks and 8.3 years (median, 2.4 years) after proton beam irradiation. Most patients (n = 94) were symptomatic before diagnosis; the remainder were first detected during screening examination. Liver involvement was documented in nearly all patients (n = 136). The majority of patients had died from metastases by the close of the study (n = 137). Significantly longer survival occurred among patients diagnosed during screening examination (P = 0.004) and among young patients (P = 0.03). The majority of patients received some form of treatment for metastases (69%). Median survival was 2.0 months for patients receiving no treatment compared with 5.2 months for those receiving treatment for metastases (P = .0001). However, the overall 1-year survival rate was poor (13%). Prophylactic adjuvant therapy could be explored as a means to increase disease-free survival in patients with uveal melanoma.

Adult↗
PubMed1989

Survival of chlorine-injured enterotoxigenic Escherichia coli in an in vitro water system.

Survival of chlorine-injured and noninjured subpopulations of enterotoxigenic Escherichia coli was compared in KH2PO4-buffered water and chlorine-neutralized tap water. Injured cells were no less persistent than noninjured cells and did not exhibit limited survival as a consequence of chlorine injury. At high inoculum densities, some injured cells were able to repair, apparently owing to the accumulation of materials arising from the chlorination procedure.

Analysis of Variance↗
PubMed1987

Effect of chlorine injury on heat-labile enterotoxin production in enterotoxigenic Escherichia coli.

Heat-labile enterotoxin (LT) production was examined in chlorine-injured and noninjured populations of enterotoxigenic Escherichia coli (ETEC) by passive immune hemolysis and Y-1 mouse adrenal tumor cell assays. Sublethally injured populations showed reduced LT production after 1, 2.5, and 4 h incubation in trypticase soy broth plus 0.25% glucose, pH 8.0. Reduction was observed during injury, resuscitation, and for at least 1.5 h following repair. LT levels comparable with that present in noninjured cells were found after 24 h incubation in the same medium, indicating delayed toxigenesis rather than permanent damage. Chlorinated populations failed to incorporate [14C]glucose until repair was completed suggesting a possible explanation for delayed toxin production. The results indicate a temporary loss of virulence among sublethally injured ETEC in chlorinated waters.

Adrenal Gland Neoplasms↗
PubMed1983

Chlorine-induced damage to surface adhesions during sublethal injury of enterotoxigenic Escherichia coli.

A comparison of the adhesive ability of noninjured and chlorine-injured enterotoxigenic Escherichia coli was made by in vitro attachment to human peripheral leukocytes. Chlorination selected for noninjured cells with greater capabilities for colonizing the small intestine. Injured populations exhibited reduced association with leukocytes. Maximum reduction was seen in populations with greater than 80% injury. These cells demonstrated less adhesive ability than nonpiliated populations. Electron micrographs suggested that reduced adhesive ability was due to the loss of surface structures as a consequence of sublethal chlorination. The data imply a reduced ability among chlorine-injured pathogens to colonize the small intestine and initiate disease.

Adhesins, Escherichia coli↗
PubMed1982

Chronic electrical stimulation of auditory nerve in cat: Physiological and histological results.

Cats were implanted with two-channel scala tympani bipolar electrode arrays consisting of four PtIr wires in a molded silicone rubber carrier. The electrically evoked auditory brainstem response (ABR) was recorded to monitor the physiological response to biphasic pulsatile stimulation in these chronic preparations. Baseline data were collected over a 1-6 month period. Animals were then subjected to a long period of continuous high level stimulation delivered through a system designed to insure delivery of charge-balanced biphasic waveforms. Subsequent changes in physiological response were interpreted as indicating electrically induced damage to the cochlea. Localized loss of hair cells and growth of connective tissue resulted from the implantation of scala tympani inserts. Electrically evoked ABR responses were not altered by the long-term presence of the electrode, nor by the presence of intervening connective tissue. Physiological manifestations of stimulus-induced change appeared only after hundreds of hours of continuous stimulation. Apparent functional damage was not suspended or reversed with cessation of stimulation, but rather continued for several hundred hours after the stimulation was terminated. Deterioration of physiological response was accompanied by two deleterious histological changes: (a) bone growth within the scala tympani; and (b) loss of nerve fibers and spiral ganglion cells. Both of these changes were restricted to an area corresponding to the implant intracochlear location and were most marked in the region adjacent to the chronically stimulated electrode pair. In cases where stimuli were not charge balanced or surgical trauma was incurred, bone growth was most extensive and nerve damage most pervasive. The data from cases stimulated at lower levels of charge density, i.e. 20-40 muC/cm2, suggest that these may be more feasible levels for safe chronic electrical stimulation in scala tympani.

Acoustic Stimulation↗
PubMed1980

Some practical considerations in development of multichannel scala tympani prostheses.

There are several basic issues regarding the safety and feasibility of implanting multichannel scala tympani cochlear prostheses in humans. Physiological and technical studies have been designed to resolve some of these questions. Results of physiological investigations demonstrate that (1) nerve viability is not affected by the presence (without activation) of a multichannel array; (2) use of a highly specified bipolar electrode configuration permits discrete and predictable stimulation of sectors of the auditory nerve array, and (3) some deleterious effects (i.e., nerve damage and calcification products) may result when stimulus parameters (intensity, duration and waveform symmetry) are not well controlled over long periods of stimulation. Results of technical investigations regarding the specifications (materials and design) of multi-electrode arrays and engineering studies regarding hardware and software for safe and efficient stimulators for humans have provided devices with which 2 patients could be implanted and tested psychophysically. Some preliminary results of testing with these provide data regarding threshold, loudness discrimination and pitch perception.

Accident Prevention↗
PubMedDate not supplied

Uterine fibroid embolization: measurement of health-related quality of life before and after therapy.

OBJECTIVE: To determine the change in health-related quality of life associated with uterine fibroid embolization (UFE). MATERIALS AND METHODS: A health-related quality-of-life questionnaire was administered before and after therapy. The questionnaire contained validated scales from the Medical Outcomes Study, with additional domains and symptom items specific to fibroids. Patients treated with UFE for symptomatic uterine leiomyomata completed a health-related quality of life questionnaire before therapy. A follow-up quality of life questionnaire and an additional brief questionnaire to assess symptom improvement were completed 3 and 6 months postprocedure. Confirmatory reliability and validity testing was also conducted. Mean scores for each scale on the quality of life questionnaire were calculated and change scores were computed. RESULTS: Fifty women were enrolled in the study and completed the baseline assessment. Health-related quality of life scores improved in all instances at follow-up. Mean change scores were statistically significant for all domains between baseline and month 3 (P < .01) and between baseline and month 6 (P < .05) except backache (P = .12). CONCLUSION: Patients undergoing UFE report significant improvements in health-related quality of life and fibroid-specific symptoms. These findings suggest that the measurement of health-related quality of life may be an effective means of comparing the outcome of UFE with other fibroid therapies.

Adult↗