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Biomedical subjects

A M Miller

Publications and source records attributed to A M Miller.

At least 19 recordsLinked to original sources
PubMed2001

Inhibition by leukocyte depletion of neointima formation after balloon angioplasty in a rabbit model of restenosis.

OBJECTIVE: The aim of the current study was to examine neointima formation in balloon injured left subclavian artery of rabbits subjected to two different methods of leukocyte depletion at the time of injury. METHODS: Angioplasty of the left subclavian artery was performed in leukopenic male New Zealand White rabbits. Depletion of circulating leukocytes was induced by either mustine hydrochloride or an antibody against leukocyte common antigen (anti-LCA) before angioplasty. Left and right subclavian arteries were removed 28 days after injury for morphological analysis and measurement of neointimal size. At the same time, leukocytes were isolated from autologous rabbit blood for 51Cr-labelling for assessment of leukocyte adhesion to injured and non-injured artery segments. RESULTS: Leukopenia decreased neointima formation in injured arteries (neointimal area was 0.09+/-0.03 mm(2) in mustine-treated arteries, n=8, vs. 0.56+/-0.07 mm(2) in control arteries, n=7; P<0.001 and 0.07+/-0.01 mm(2) in anti-LCA treated arteries, n=9, vs. 0.22+/-0.04 mm(2) in non immune serum-treated arteries, n=9; P<0.001). Adventitial fibrosis was also significantly (P<0.05) decreased by both leukopenic interventions. Neither medial nor adventitial area was modified in any of the groups. No differences in leukocyte adhesion were observed between injured and non-injured arteries in any of the experimental groups at the 28 day time point. CONCLUSION: These results suggest that leukocytes play a major role in the development of two of the major characteristics of the response to balloon injury, namely formation of neointima and adventitial fibrosis, that currently limit the success of clinical angioplasty. Elucidation of the fine mechanisms involved in leukocyte-mediated injury may lead to the discovery of novel therapeutic targets for the prevention of restenosis.

Angioplasty, Balloon↗
PubMed2001

Measuring adherence to a women's walking program.

The purpose of this study is to demonstrate the use of a self-report exercise log and a heart-rate monitor in the measurement of adherence to the dimensions of an exercise prescription and to propose an alternative way to define adherence to a 24-week home-based women's walking program, which reflects the dynamic process of behavior change. Adherence was measured with exercise logs, Polar Vantage XL Heart-Rate Monitors, and pre- to postintervention change in VO2 max. Of the dimensions of the exercise prescription, frequency of walks documented by both the heart-rate monitor and the exercise log had a higher correlation than duration and intensity of walking, with change in VO2 max suggesting that frequency was potentially the most predictive adherence measure. Examination of the total number of walks and the number and sequence of weeks without walks over the 24-week intervention revealed dynamic patterns of adherence suggesting variation in the degree of behavioral change.

Aged↗
PubMed2000

Post-cardiac transplantation gout: incidence of therapeutic complications.

OBJECTIVE: To study the clinical impact of gout treatment following cardiac transplantation. METHODS: We performed an audit of all cardiac transplant recipients of the Alfred Hospital before August 1998 who lived in Victoria. RESULTS: We studied 225 patients (81% men), with a mean post-transplant follow-up of 50.8 months (SD 36). Forty-three (19%) had pre-transplant gout, 19 recurring post-transplantation. Twenty-three patients developed gout de novo. Of the 24 patients who received allopurinol, 6 developed pancytopenia and required hospitalization. Fourteen received a change in immunosuppression: in 5 patients following pancytopenia, and in 9 to enable safe use of allopurinol. Thirty-two patients received colchicine; 5 developed neuromyopathy. Impaired renal function, diuretic use, and hypertension were more common in this sub-group. Non-steroidal anti-inflammatory agents, used in 16 patients, caused serious complications in 1 patient (life-threatening peptic ulceration and hemorrhage, precipitating dialysis-dependent chronic renal failure). CONCLUSIONS: Cardiac transplant recipients, when treated for gout, are at high risk of therapeutic complications. Thus, gout treatment significantly affects care, health, and immunosuppression of these patients.

Adolescent↗
PubMed2000

Sexual but not reproductive: exploring the junction and disjunction of sexual and reproductive rights.

Although the term "sexual rights" has gained widespread currency, its concrete scope and content have not yet been fully defined. The need for definition is critical not only for promoting governmental accountability but also for ensuring that sexual rights can be claimed by diverse persons around the world. Ironically, the concept of "sexual and reproductive rights" poses a challenge to this effort; practices and people not traditionally addressed by reproductive rights work must be explicitly named and protected. This article considers how international norms have contributed to a gendered regulation of sexuality and of contemporary theories of "socially constructed sexuality," and it proposes a focus on the conditions that contribute to the ability to choose and on the links between sexuality, conduct, identity, social structures, and reproduction. Given the probable politically charged responses, global coalition-building is needed.

Human Rights↗
PubMed1999

Identification and immunolocalization of actin cytoskeletal components in light- and dark-adapted octopus retinas.

Photoreceptors in the octopus retina are of the rhabdomeric type, with rhabdomeres arising from the plasma membrane on opposite sides of the cylindrical outer segment. Each rhabdomere microvillus has an actin filament core, but other actin-binding proteins have not been identified. We used immunoblotting techniques to identify actin-binding proteins in octopus retinal extracts and immunofluorescence microscopy to localize the same proteins in fixed tissue. Antibodies directed against alpha-actinin and vinculin recognized single protein bands on immunoblots of octopus retinal extract with molecular weights comparable to the same proteins in other tissues. Anti-filamin identified two closely spaced bands similar in molecular weight to filamin in other species. Antibodies to the larger of the Drosophila ninaC gene products, p174, identified two bands lower in molecular weight than p174. Anti-villin localized a band that was significantly less in molecular weight than villin found in other cells. Epifluorescence and confocal microscopy were used to map the location of the same actin-binding proteins in dark- and light-adapted octopus photoreceptors and other retinal cells. Antibodies to most of the actin-binding proteins showed heavy staining of the photoreceptor proximal/supportive cell region accompanied by rhabdom membrane and rhabdom tip staining, although subtle differences were detected with individual antibodies. In dark-adapted retinas anti-alpha-actinin stained the photoreceptor proximal/supportive cell region where an extensive junctional complex joins these two cell types, but in the light, immunoreactivity extended above the junctional complex into the rhabdom bases. Most antibodies densely stained the rhabdom tips but anti-villin exhibited a striated pattern of localization at the tips. We believe that the actin-binding proteins identified in the octopus retina may play a significant role in the formation of new rhabdomere microvilli in the dark. We speculate that these proteins and actin remain associated with an avillar membrane that connects opposing sets of rhabdomeres in light-adapted retinas. Association of these cytoskeletal proteins with the avillar membrane would constitute a pool of proteins that could be recruited for rapid microvillus formation from the previously avillar region.

Actinin↗
PubMed1999

Limited erythropoietic response to combined treatment with recombinant human interleukin 3 and erythropoietin in myelodysplastic syndrome.

Twenty-two patients with myelodysplastic syndrome were treated with combined recombinant human erythropoietin and recombinant human interleukin 3 (rHuIL-3). All 22 patients were evaluable for toxicity and 21/22 for response. Thirteen patients (62%) required rHuIL-3 dose reduction because of toxicity. Nineteen experienced a 50% or greater rise in neutrophil count. Of seven patients with initial platelet counts of > 100,000, three experienced increases of > 15,000/ml while an equal number had a comparable decline. Five patients (21%) experienced a significant rise in reticulocyte count, and two transfusion-dependent patients experienced a significant decrease in transfusions. Erythroid burst-forming units were increased by > or = 50% in nine of 11 patients after combined therapy. Similar changes were seen in multipotential colony-forming units. Clinical responses were comparable to results obtained with epo alone while toxicities due to IL-3 were significant.

Aged↗
PubMed1999

The pretectum mediates rapid eye movement sleep regulation by light.

A variety of sensory stimuli (e.g., visual, auditory, and thermal) are known to induce rapid eye movement (REM) sleep in mammals. Studies have examined the induction of REM sleep in albino rats by light-to-dark transitions, a phenomenon referred to as REM sleep triggering. Recent research has demonstrated that aspiration lesions of the superior colliculus (SC) and pretectal area attenuated REM sleep triggering. To define more specifically the area or areas involved in mediating REM sleep responses to changes in illumination, fiber-sparing neurotoxic lesions were made to the pretectum (PT) or the SC. Lesions of the PT attenuated REM sleep triggering, whereas lesions of the SC did not. Thus, the role of the PT may be expanded to include the regulation of REM sleep in response to photic stimulation in albino rats. These findings provide a paradigm in which to study mechanisms of REM sleep generation and the effects of light on behavioral state.

Animals↗
PubMed1999

Anticoagulant therapy, anti-platelet agents and gastrointestinal endoscopy.

BACKGROUND: The increasing use of anticoagulant therapy and anti-platelet agents in the primary and secondary prevention of cardiovascular, cerebrovascular and venous thromboembolic disease has increased the need for guidelines for managing these agents prior to gastrointestinal endoscopy, particularly if therapeutic manoeuvres are required. The continuation of anticoagulant therapy increases the risk of haemorrhagic complications of gastrointestinal endoscopy. Temporary suspension of anticoagulant therapy exposes the patient to the risk of thromboembolism associated with the underlying condition requiring anticoagulant treatment. CONCLUSIONS: This article reviews the literature and proposes guidelines for the management of patients taking anticoagulant and anti-platelet agents who require gastrointestinal endoscopy.

Anticoagulants↗
PubMed1999

Women's occupations, energy expenditure, and cardiovascular risk factors.

The purpose of this study was to examine the cardiovascular risk factors and energy expenditure of women from occupations that differ by physical activity level and socioeconomic level. Participants included 171 women randomly selected from employee lists at 10 employment sites. Measures included blood pressure, body mass index, levels of total and high-density lipoprotein (HDL) cholesterol, a submaximal aerobic fitness test on a bicycle ergometer, and a 12-month retrospective self-report of occupational, leisure time, and household energy expenditure. Women in active occupations had lower total cholesterol and higher HDL cholesterol than women in sedentary occupations. Women with higher occupational energy expenditure scores had higher HDL cholesterol and lower total cholesterol than women with lower occupational energy scores. Findings suggest that cardiovascular benefits, particularly for lipid profiles, may be derived from even small increases in occupational physical activity. The workplace may offer an environment for initiating policies to facilitate increased physical activity among women.

Activities of Daily Living↗
PubMed1998

The superior colliculus-pretectum mediates the direct effects of light on sleep.

Light and dark have immediate effects on sleep and wakefulness in mammals, but the neural mechanisms underlying these effects are poorly understood. Lesions of the visual cortex or the superior colliculus-pretectal area were performed in albino rats to determine retinorecipient areas that mediate the effects of light on behavior, including rapid eye movement sleep triggering by lights-off and redistribution of non-rapid eye movement sleep in short light-dark cycles. Acute responses to changes in light conditions were virtually eliminated by superior colliculus-pretectal area lesions but not by visual cortex lesions. Circadian entrainment was evident in both groups with lesions and in normal controls. Thus, acute light-dark effects on sleep and wakefulness appear to be mediated independently from cortical vision or circadian rhythms.

Animals↗
PubMed1998

Chronic myelogenous leukemia and porphyria cutanea tarda in a patient with limited systemic sclerosis.

Systemic sclerosis is uncommonly associated with hematologic malignancies. We report the case of a patient who had chronic myelogenous leukemia 3 years after the CREST variant of systemic sclerosis was diagnosed. She also later had porphyria cutanea tarda. The majority of patients who had hematologic malignancies after the diagnosis of systemic sclerosis proved to have either multiple myeloma or chronic lymphocytic leukemia. Hematologic malignancies may be found in patients with systemic sclerosis (either limited or diffuse).

Adult↗
PubMed1998

Antibiotic-associated haemorrhagic colitis.

Antibiotic-associated haemorrhagic colitis is an uncommon cause of bloody diarrhoea in patients taking penicillin or penicillin-related antibiotics. Symptoms of abdominal pain and bloody diarrhoea occur within 1 week of antibiotic use and resolve without specific therapy within days of discontinuing the offending antibiotic. There is an apparent increased incidence of the disease in patients of Oriental ethnicity. The pathogenesis is unknown. We present two cases of haemorrhagic colitis in patients taking penicillin-related antibiotics who presented within 4 months of each other. One of the patients was being treated for Helicobacter pylori infection. The published literature is reviewed with particular emphasis on the histology and pathogenesis of the condition.

Adult↗
PubMed1998

Standardizing faculty evaluation of nurse practitioner students by using simulated patients.

Biases related to variations among patients and settings may be reduced by having faculty evaluate the clinical skills of students as they interact with simulated patients. The Student Clinical Performance Scale is a rating scale developed to standardize assessment of videotaped simulated patient encounters with family nurse practitioner students. In a pilot study of faculty interrater reliability, correlation coefficients for independent scoring by faculty pairs using the Student Clinical Performance Scale varied widely among six case studies, and several scenario- and faculty-related factors served as systematic sources of faculty variability. The findings demonstrate the importance of a rigorous approach to developing and testing instruments that guide measurement of clinical competence. The use of simulated patients to evaluate nurse practitioner students provides opportunities to assess a wide range of attributes and holds promise for assessing advanced clinical skills in controlled educational environments.

Clinical Competence↗
PubMed1998

Sociodemographic characteristics, biological factors, and symptom reporting in midlife women.

OBJECTIVE: The purpose of this study is to examine the influence of sociodemographic characteristics, reproductive hormones, and body composition on symptoms reported by generally well midlife women. DESIGN: The design was a 24-cell, randomly selected quota sample, stratified by four occupations that varied in professional status, two races, and three age groups. One hundred fifty-three women, aged 35 to 69, who worked 20 or more hours a week, who were not on hormone replacement therapy, who were not pregnant, and who did not have a hysterectomy prior to the age of 53 participated in the study. Data were collected at 10 employment sites. Symptoms were assessed by a 22-item symptom index. Serum hormone levels of estradiol and follicle stimulating hormone (FSH) were drawn for each woman, and body composition was assessed by body mass index (BMI). RESULTS: Chi-square tests showed that significantly more White women than Black women experienced nervous tension, loss of urine, and vaginal dryness. Analyses of variance showed that women experiencing hot flashes had significantly higher FSH levels, lower estradiol levels, and higher BMI than women not experiencing this symptom. Estradiol (odds ratio 0.988) and BMI (odds ratio 1.094) were significant predictors of experiencing hot flashes when entered into a stepwise logistic regression with age and FSH level as covariates. CONCLUSIONS: Findings suggest that symptoms experienced by midlife women are consistent across races, and that interventions targeting weight reduction may improve hot flashes experienced by midlife women.

Adult↗
PubMed1998

Social role quality and psychological well being in employed black and white midlife women.

This study examined relationships among job, partner, and parent role quality and psychological well being in midlife black (n = 51) and white (n = 56) women employed in occupations varying by socioeconomic status (SES). Oversampling for black women ensured balanced occupational representation, allowing investigation uncontaminated by SES. Instruments included Baruch and Barnett's Rewards and Concerns Scales, Bradburn Affect Balance Scale, and Center for Epidemiological Studies Depression Scale (CES-D). Better well being scores were reported by black women than whites, and by professionals than non-professionals. However, when race, occupational group, and menopausal status were held constant in a multiple regression analysis, partner role quality was significantly related to both well being scores, parent role quality was related to life satisfaction only, and job role quality was not related to either. Nurses in the workplace can help women identify problematic aspects of their multiple social roles, and facilitate resolution of problems to improve worker health.

Adult↗
PubMed1997

Lipoxygenase metabolism is required for interleukin-3 dependent proliferation and cell cycle progression of the human M-07e cell line.

The cell line M-07e requires either Interleukin-3 (IL-3) or granulocyte-macrophage colony stimulating factor (GM-CSF) for proliferation in vitro. Cells deprived of growth factor for up to 48 hours remain viable but no longer divide. The growth-factor-deprived M-07e cells begin to divide within 48 hours of reexposure to IL-3. Flow cytometric analysis of M-07e cells labeled with hypotonic propidium iodide demonstrates that the percentage of cells undergoing DNA synthesis decreases from 24%, in a log phase population of IL-3 stimulated cells, to 1% when cells are deprived of IL-3 for 24 hours. IL-3-deprived cells accumulate predominantly in a flow cytometry peak representative of G0/G1. DNA synthetic activity, as determined by tritiated thymidine uptake and flow cytometry, resumes between 12 and 18 hours after reexposure to IL-3, reaching a peak of up to 40% by 24 hours and returning to log phase levels by 72 hours. Prior to initiation of DNA synthesis, increases are seen in mRNA levels for five-lipoxygenase-activating protein (FLAP). Following reexposure to IL-3, a rapid time-dependent biosynthesis of leukotriene D4 (LTD4) is induced by M-07e cells. When IL-3 is added in the presence of any of three lipoxygenase inhibitors tested (Piriprost, caffeic acid, nordihydroguiaretic acid) or FLAP inhibitor, MK-886, there is dose-dependent inhibition of the resumption of proliferation and of DNA synthesis. Flow cytometric cell cycle analysis demonstrates that the inhibited cells remain in the G0/G1 population and do not progress through the cell cycle. These results are consistent with our previous observation that an intact lipoxygenase pathway is necessary for hematopoietic growth-factor-stimulated colony formation of normal bone marrow myeloid progenitors and suggest that the induction of a lipoxygenase metabolite or metabolites is necessary for myeloid cells to progress through the cell cycle when stimulated by a hematopoietic growth factor.

5-Lipoxygenase-Activating Proteins↗