PubMed Health⌕ Search

Biomedical subjects

S A Washburn

Publications and source records attributed to S A Washburn.

13 recordsLinked to original sources
PubMed2001

Developing socio-spatial knowledge networks: a qualitative methodology for chronic disease prevention.

Chronic disease is a significant and costly social problem. The burden is even more pronounced in communities with high rates of a particular chronic disease. Assessment of health belief systems and the local geographies of health beliefs can assist community health planners to create cost-effective strategic intervention programs where populations are at high risk for chronic diseases. In this paper, we elaborate the concept of socio-spatial knowledge networks (SSKNs) and demonstrate that SSKNs can be useful in informing the design of health care prevention strategies. In our project, we demonstrate how to identify key socio-spatial information for intervention strategies which will prevent or delay the onset of a particular chronic disease, Type 2 diabetes. Our qualitative framework allows us to determine which sites might be best characterized as socio-spatial knowledge network nodes for sharing diabetes information and which sites might be less suited to such exchange. Our strategy explores cross-cultural similarities, differences, and overlap in a multi-ethnic rural North Carolina context through simple techniques such as mapping social networks and sites in which people share their knowledge and beliefs about diabetes. This geographical analysis allows us to examine exactly where health knowledge coincides with other social support, and where such resources may be improved in a particular community. Knowing precisely what people in a community understand about a chronic disease and its treatment or prevention and knowing where people go to share that information helps to (1) identify strategic locations within a community for future interventions and, (2) evaluate the effectiveness of existing interventions. The geographical approach presented here is one that can serve other communities and health practitioners who hope to improve chronic disease management in diverse local environments.

Aged↗
PubMed1999

Health potential of soy isoflavones for menopausal women.

OBJECTIVE: To review the current literature on the effects of soy isoflavones, one class of phyto-oestrogens, on cardiovascular diseases, osteoporosis, cancer and climacteric symptoms. DESIGN: Many study designs were employed in the reports reviewed here, including prospective human trials, observational human studies, animal experiments and in vitro cell studies that explored the protective or preventive effects of soy isoflavones (genistein, daidzein and glycitein alone or mixed). SETTING: Diverse settings were employed, depending on study design. SUBJECTS: Human subjects, mostly menopausal or postmenopausal, were included, as were animal models and specific cell types. RESULTS: The findings were: (i) isoflavones plus soy protein together were needed to obtain the highly significant beneficial results on blood lipids and arterial dimensions; (ii) isoflavone treatments alone at high doses (relative to above) consistently improved bone parameters in rodent ovariectomized models, but not in humans or primates; (iii) isoflavones were not consistent in exerting positive effects regarding the prevention or treatment of cancers of the mammary glands, uterus and colon; and (iv) the effects of isoflavones on climacteric symptoms were not clear-cut. CONCLUSIONS: The promise of soy isoflavones reducing chronic disease risk seems to be non-uniform, with the most conclusive benefits occurring in the prevention of cardiovascular diseases, but other organ systems, such as skeletal and reproductive tissues, may also benefit from the consumption of soy and soy-derived products.

Animals↗
PubMed1997

17alpha-Dihydroequilenin increases hippocampal dendritic spine density of ovariectomized rats.

The effects of estradiol and 17alpha-dihydroequilenin on the apical dendrite spine density of pyramidal cells of the CA1 region of rat hippocampus were compared. 17alpha-Dihydroequilenin was as effective as estradiol in increasing spine densities relative to controls. 17alpha-Dihydroequilenin is not uterotrophic like estradiol but does have beneficial effects on the cardiovascular system, suggesting that it may be an effective single-agent hormone replacement therapy to treat menopausal symptoms and reduce chronic disease risk in menopausal women.

Animals↗
PubMed1996

Effects of estrogen and progestin replacement on the urogenital tract of the ovariectomized cynomolgus monkey.

Menopause is presumed to have a causative role in the development of female urinary incontinence. While some clinical trials have shown that estrogen can affect urinary tract function, our knowledge of the pathophysiologic changes resulting from menopause and hormone replacement therapy is poor. The cynomolgus monkey is a well-established model for study of menopause and hormone replacement therapy, particularly in the cardiovascular arena. We have utilized this animal model to determine the histologic effects of estrogen and estrogen/progestin replacement therapy in the proximal urethra and vagina. Estrogen and estrogen/progestin replacement induced an increase in the amount of vaginal but not urethral epithelium. Hormone replacement also resulted in a significant increase in the loose, vascular component of the connective tissue layer of the urethra. The cynomolgus macaque shows promise as a useful model for further study of the effects of hormone replacement on the lower urinary tract.

Animals↗
PubMed1996

Isohemagglutinins and xenoreactive antibodies: members of a distinct family of natural antibodies.

Just as anti-blood group A and anti-blood group B antibodies pose a strong humoral barrier to the transplantation of allogeneic organs or blood, xenoreactive natural antibodies directed against Gal alpha 1-3Gal pose a barrier to the transplantation of xenogeneic organs or blood. We tested the idea that, although "natural" iso-hemagglutinins and xenoreactive natural antibodies recognize distinct structures, they have a similar origin and function. Anti-A antibodies, anti-B antibodies, and xenoreactive natural antibodies were present in serum at similar concentrations and varied with age, gender, and the concentration of total IgM in serum in a similar manner. Anti-A antibodies, anti-B antibodies, and xenoreactive natural antibodies, unlike some elicited antibodies, had a high degree of thermal lability and bound more avidly at lower temperatures. The natural antibodies manifest remarkable homogeneity and high functional avidity for determinants on a cell surface but only a weak affinity for monovalent ligands. These findings suggest that anti-A antibodies, anti-B antibodies, and xenoreactive natural antibodies specific for Gal alpha 1-3Gal have a common origin and function and, given similar antigen density on target cells, provide similar humoral barriers to transplantation or transfusion and that these antibodies may be members of a common "family" of antibodies.

ABO Blood-Group System↗
PubMed1996

Effects of 17 alpha-dihydroequilenin sulfate on atherosclerotic male and female rhesus monkeys.

OBJECTIVES: Our purpose was to determine the effects of 17 alpha-dihydroequilenin on plasma lipid and lipoprotein, glucose, and insulin concentrations; coronary artery vasomotor function; and reproductive organ and mammary gland proliferation in atherosclerotic male and female rhesus macaques. STUDY DESIGN: Fifty adult female and 33 adult male rhesus macaques were randomized to treatment by lifetime dietary cholesterol exposure and ratio of total plasma cholesterol to high-density lipoprotein cholesterol. The female treatment groups were intact female controls (n = 9), ovariectomized controls (n = 16), ovariectomized plus 0.3 mg/kg/day 17 alpha-dihydroequilenin (n = 17) and ovariectomized plus subcutaneous estradiol (n = 7). The male treatment groups were control (n = 16) and 1.25 mg/kg/day 17 alpha-dihydroequilenin (n = 17). Treatment lasted 5 weeks. Longitudinal assessments of plasma lipid and lipoprotein and glucose and insulin concentrations were performed. Coronary artery vasomotor function was assessed by quantitative coronary angiography 1 week after initiation of treatment. Morphologic and immunohistochemical assessments of proliferation index values of reproductive organs and mammary glands were done at necropsy. RESULTS: 17 alpha-Dihydroequilenin prevented endothelium-dependent vasoconstriction in males (p < 0.05) and ovariectomized females (p < 0.08). 17 alpha-Dihydroequilenin treatment increased plasma apolipoprotein A-1 concentrations (p < 0.05) and lowered fasting insulin concentrations (p < 0.05) without changing fasting plasma glucose concentrations in males. 17 alpha-Dihydroequilenin had no other effects on plasma lipid and lipoprotein concentrations in either males or females. It had no trophic effects on uterus, endometrium, or breast. There was no effect on either prostatic or testicular weight. CONCLUSION: 17 alpha-Dihydroequilenin may represent a single-agent hormone therapy for reduction of ischemic hear disease risk for both menopausal women and men. It has no apparent trophic effects on reproductive organs or mammary glands of female and male rhesus macaques.

Animals↗
PubMed1996

Uterine pyomyoma as a complication of pregnancy in an intravenous drug user.

Pyomyoma (suppurative leiomyoma) is a rare entity characterized by infarction and infection of a uterine leiomyoma. Pyomyomas may pose both diagnostic and therapeutic difficulties, leading to potential complications such as bacteremia, uterine rupture, and even death. In the case we describe, uterine pyomyoma occurred as a complication of pregnancy in a 31-year-old woman with a history of intravenous drug abuse. We postulate that the patient's illicit drug use caused transient bacteremia resulting in bacterial seeding of a uterine leiomyoma that had infarcted due to pregnancy. Therapy consisted of total abdominal hysterectomy and intravenous antibiotic administration. We believe this is the first reported case of a pyomyoma developing in association with intravenous drug abuse.

Adult↗
PubMed1996

The effects of disease severity and sex on coronary endothelium-dependent vasomotor function in an atherosclerotic primate model.

BACKGROUND: The relationship between the extent of atherosclerosis and vascular reactivity is not known, since studies of humans have used indirect measures of the extent of atherosclerosis (angiography and ultrasound), and most patients studied had only minimal-to-moderate atherosclerosis. It is known that atherosclerosis impairs coronary vasodilatation in response to acetylcholine, and that estrogen improves vascular reactivity of atherosclerotic coronary arteries in women and perhaps in men. However, the effects of estrogen and sex on arteries with advanced, complicated plaques are not known. METHODS: We used quantitative coronary angiography to measure vascular reactivity to infusions of 10(-6) mol/l acetylcholine and 15 micrograms/min nitroglycerin in 70 segments of coronary arteries in 16 rhesus monkeys (12 males, five intact females, nine ovariectomized females) with a wide range of extents of atherosclerosis. The extent and severity of atherosclerotic plaque in each segment was quantified by histologic and histomorphometric methods. Effects of sex and ovariectomy on vascular reactivity were examined at low and high levels of plaque severity. RESULTS: Vascular responses ranged from constriction (by 18%) to dilatation (by 14%) compared with the control diameter. The magnitude of the vascular response to acetylcholine, either dilatation or constriction, decreased with increasing plaque severity (P < 0.01). At low severity, arteries of intact females dilated (by 7.2 +/- 2.1%), whereas those of males and ovariectomized females constricted (by 4.5 +/- 1.5% and 5.0 +/- 1.2%, respectively; P < 0.001, versus intact females). When lesions were severe, vascular responses did not differ among groups. CONCLUSIONS: Our results indicate that arteries became unresponsive to acetylcholine as atherosclerotic lesions progressed in size and complexity, and that sex and estrogen status affected vascular reactivity only when lesions were small. These findings may imply a limited range of lesion development within which vascular reactivity can be influenced by sex and estrogen status.

Acetylcholine↗
PubMed1994

Outpatient hysterectomy: determinants of discharge and rehospitalization in 133 patients.

OBJECTIVE: This study examines our continuing experience in performing vaginal hysterectomies and laparoscopy-assisted vaginal hysterectomies with an outpatient protocol. The purpose was to review factors associated with discharge and hospitalization. STUDY DESIGN: Surgical records from all women entering our previously reported outpatient hysterectomy protocol were reviewed. Demographics, surgical indications, intraoperative data, and postoperative data were studied, and their associations with patient discharge and hospitalization were determined. Specific attention was directed to complications. RESULTS: The study group consisted of 133 women. Twelve women (9.0%) were not discharged from the hospital and 5 (3.8%) required readmission. Surgical indications, the type of hysterectomy, and the requirement for pain medication revealed no association with hospitalization. The occurrence of an intraoperative complication (p < 0.000), the need for transfusion (p = 0.043), and postoperative antiemetics (p = 0.013) were statistically associated with hospitalization. In addition, low hematocrit values and elevated temperatures on the first and second postoperative days were associated with hospitalization. CONCLUSION: Long-term experience with outpatient hysterectomy reveals a hospitalization rate of 12.8%. Complications, blood loss, elevated temperatures, and postoperative nausea are the major determinants of patient discharge and hospitalization. Readmission rates continue to remain low.

Adolescent↗
PubMed1994

Effects of hormone replacement therapy on reactivity of atherosclerotic coronary arteries in cynomolgus monkeys.

OBJECTIVES: We attempted to determine whether continuous and cyclic medroxyprogesterone acetate modulates the effects of estrogen on dilation of atherosclerotic coronary arteries in surgically postmenopausal female monkeys. BACKGROUND: Estrogen replacement in postmenopausal women preserves normal dilator responses of atherosclerotic coronary arteries. The effects of progestins on coronary artery reactivity have not been determined. METHODS: Repeated quantitative coronary angiography was used to study the effects after 1 month of 1) no hormone replacement (control) or oral administration of 2) continuous conjugated equine estrogens, 3) cyclic high dose medroxyprogesterone acetate (MPA) given on days 16 to 26 of the month, 4) conjugated equine estrogens plus continuous low dose MPA, or 5) conjugated equine estrogens plus cyclic high dose MPA on endothelium-mediated dilation of atherosclerotic coronary arteries in 12 cynomolgus monkeys. Change in diameter of the left circumflex coronary artery was measured in response to intracoronary infusions of acetylcholine (10(-6) mol/liter per min) and nitroglycerin (15 micrograms/min). RESULTS: Coronary arteries constricted during no hormone treatment (-8 +/- 3% [mean +/- SEM]), dilated during conjugated equine estrogen treatment (+3 +/- 1%, p < 0.05 vs. control) and constricted during cyclic MPA treatment (-3 +/- 2%). Addition of cyclic or continuous MPA to the conjugated equine estrogen regimen inhibited acetylcholine responses by 50% (p < 0.05 vs. conjugated equine estrogens). There was no effect of treatment on vascular response to nitroglycerin (p > 0.05). CONCLUSIONS: Treatment with conjugated equine estrogens, but not MPA, augmented endothelium-mediated dilation of atherosclerotic coronary arteries. Addition of cyclic or continuous MPA to the conjugated equine estrogen regimen diminished endothelium-mediated dilation.

Animals↗
PubMed1994

Gonadotropin-releasing hormone agonist use before hysterectomy.

OBJECTIVE: Our purpose was to compare the effects of leuprolide acetate in patients with symptomatic uterine leiomyoma before hysterectomy. STUDY DESIGN: Group I (n = 90) included patients with a pretreatment uterine size of 14 to 18 gestational weeks and group II (n = 60) included patients with uteri > 18 weeks' gestational size. Patients in both groups were randomized to either immediate hysterectomy or 2 months of preoperative gonadotropin-releasing hormone agonist. RESULTS: All patients in the two groups with a pretreatment hemoglobin < 11.0 gm/dl randomized to agonist had a significant (p < 0.05) increase (> or = 1.5 gm/dl) in hemoglobin level. Patients in group I who received preoperative agonist were more likely to undergo vaginal hysterectomy (80% vs 13%, p < 0.05) than were patients who did not receive preoperative agonist. Patients undergoing vaginal hysterectomy had a shorter hospital stay, decreased operative blood loss, and a shorter convalescence period than did those undergoing abdominal hysterectomy. In group II, in spite of a mean uterine volume reduction of 51.3%, intraoperative morbidity, operative blood loss, hospital stay, and postoperative convalescence period did not differ between treatment arms. CONCLUSION: The preoperative administration of gonadotropin-releasing hormone agonist in patients with a uterus of 14 to 18 weeks' size increases the use of vaginal hysterectomy, decreases intraoperative blood loss, and shortens hospital stay and convalescence. Preoperative gonadotropin-releasing hormone agonist for patients with a preoperative hemoglobin < 11.0 gm/dl reduces the risk of preoperative transfusion. Preoperative gonadotropin-releasing hormone use in the nonanemic patient with a uterine size > or = 18 weeks' gestational size doses not appear to lower operative morbidity.

Adult↗
PubMed1993

A conjugated equine estrogen with differential effects on uterine weight and plasma cholesterol in the rat.

OBJECTIVE: Our purpose was to determine the effect of Premarin (conjugated estrogens) and three of its component estrogens on uterine weight and plasma cholesterol concentrations in surgically menopausal female rats. STUDY DESIGN: A randomized trial of Premarin and three component estrogens--estrone sulfate, 17 alpha-estradiol sulfate, and 17 alpha-dihydroequilenin sulfate--in female rats after oophorectomy. RESULTS: High-dose Premarin and high- and middle-dose estrone sulfate significantly increased uterine weight relative to untreated controls (high-dose Premarin, 243.34 +/- 0.15 mg; high-dose estrone sulfate, 376.1 +/- 9.36 mg; middle-dose estrone sulfate, 249.0 +/- 6.34 mg; untreated controls, 124.63 +/- 3.17 mg; for all, p < 0.05). 17 alpha-Dihydroequilenin sulfate had no effect on uterine weight relative to controls. All 17 alpha-dihydroequilenin sulfate doses markedly reduced total plasma cholesterol concentrations versus controls (34.02 +/- 3.44 mg/dl, 32.49 +/- 1.08 mg/dl, and 71.55 +/- 5.16 mg/dl vs 90.44 +/- 1.06 mg/dl; for all, p < 0.02). 17 alpha-Dihydroequilenin sulfate had a more pronounced effect on low- or very-low-density lipoprotein cholesterol than total plasma cholesterol or high-density lipoprotein cholesterol concentrations. CONCLUSIONS: 17 alpha-Dihydroequilenin sulfate reduced total plasma cholesterol concentrations without inducing uterine growth in rats after oophorectomy.

Animals↗