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Davis S, Gerraty R. Heparin in acute ischaemic stroke. Med J Aust 1999; 170:566-8. [PMID: 10397055 DOI: 10.5694/j.1326-5377.1999.tb127893.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Davis S. Injection drug use and HIV infection among the seriously mentally ill: a report from Vancouver. CANADIAN JOURNAL OF COMMUNITY MENTAL HEALTH = REVUE CANADIENNE DE SANTE MENTALE COMMUNAUTAIRE 1999; 17:121-7. [PMID: 10351170 DOI: 10.7870/cjcmh-1998-0007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A recently reported outbreak of HIV among injection drug users in Vancouver determined that, in early 1997, 23% of this population was HIV-positive, and that HIV-negative injection drug users were becoming positive at the rate of 18.6% per year, the highest rate reported in North America. One significant factor behind the outbreak is the high prevalence of injection cocaine use among drug addicts in Vancouver. Cocaine, because it has a short "high," creates a need for more frequent injections and therefore increases the likelihood of needle sharing and HIV transmission. The mentally ill in Vancouver are particularly at risk for HIV infection because of their vulnerability to substance misuse and because large numbers of them reside in the main drug-using neighborhood. The provincial and federal governments have made $4,700,000 available to respond to this public health emergency, to be spent on the expansion of community services, including a number of needle-exchange sites. Accessing these and other health care services continues to be a challenge for injection drug users who also suffer from serious mental illnesses; for these persons an assertive case management model may be the most effective way of maintaining continuity of care.
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Simpson E, Rubin G, Clyne C, Robertson K, O'Donnell L, Davis S, Jones M. Local estrogen biosynthesis in males and females. Endocr Relat Cancer 1999; 6:131-7. [PMID: 10731101 DOI: 10.1677/erc.0.0060131] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
It is now apparent that in men and in postmenopausal women, estrogens have important physiological and pathophysiological roles. However, importantly, these actions are at a local level, namely paracrine, autocrine, and even 'intracrine' rather than endocrine in the classical sense. Thus for example local estrogen biosynthesis in the bones of men plays a hitherto unsuspected role in the maintenance of bone mineralization and in epiphyseal fusion; and in the testes, estrogen is essential for male germ cell development. On the other hand, in postmenopausal women, the mesenchymal cells of the breast are the major source of estrogen responsible for breast cancer development. This realization points to the importance of circulating C19 precursors in the maintenance of adequate estrogen biosynthesis in extragonadal sites and suggests the possibility of new therapies to block estrogen synthesis in a tissue-specific fashion.
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Anwer K, Earle KA, Shi M, Wang J, Mumper RJ, Proctor B, Jansa K, Ledebur HC, Davis S, Eaglstein W, Rolland AP. Synergistic effect of formulated plasmid and needle-free injection for genetic vaccines. Pharm Res 1999; 16:889-95. [PMID: 10397610 DOI: 10.1023/a:1018834305079] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE A plasmid-based gene expression system was complexed with protective, interactive, and non-condensing (PINC) polymer system and administered with Medi-Jector, a needle-free injection device (NFID), to achieve high and sustained levels of antigen-specific antibodies in blood circulation. METHODS Human growth hormone (hGH) or bacterial beta-galactosidase gene expression plasmids driven by a cytomegalovirus (CMV) promoter were formulated in saline or complexed with a PINC polymer, polyvinylpyrrolidone (PVP), and intramuscularly or subcutaneously administered into dogs and pigs using a 22-gauge needle or a NFID. The hGH-specific IgG titers in serum were measured by an ELISA. Beta-galactosidase expression was measured in injected muscles by an enzymatic assay or immunohistochemistry. The effect of NFID on DNA stability and topology was assessed by gel electrophoresis. RESULTS Intramuscular (i.m.) or subcutaneous (s.c.) injection of a hGH expression plasmid pCMV-hGH (0.05-0.5 mg/kg) in dogs and pigs elicited antigen-specific IgG antibody titers to expressed hGH. With both routes of injection, pDNA delivery by a NFID was superior to pDNA injection by needle. The magnitude of hGH-specific IgG titers with NFID was 15-20-fold higher than needle injection when pDNA was complexed with PVP, and only 3-4-fold higher with pDNA in saline. The transfection efficiency in the injected muscle, as measured by beta-galactosidase expression, following i.m. injection of pCMV-betagalactosidase/PVP, was not significantly different between needle and NFID-injected groups. CONCLUSIONS These data demonstrate that the combination of pDNA/ PVP complexes and a NFID act synergistically to achieve high and sustained levels of antigen-specific IgG response to expressed antigen. This gene delivery approach may offer advantage over needle injection of naked DNA for the development of genetic vaccines.
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Abstract
There is increasing evidence to suggest that many postmenopausal women experience symptoms alleviated by androgen therapy and that such symptoms may be secondary to androgen deficiency. Affected women complain of fatigue, low libido, and diminished well-being, symptoms easily and frequently attributed to psychosocial and environmental factors. When such symptoms occur in the setting of low circulating bioavailable testosterone, testosterone replacement results in significant improvement in symptomatology and, hence, quality of life for the majority of women. Whether the apparent therapeutic effects of testosterone replacement are mediated by testosterone and its metabolite 5alpha- dihydrotestosterone or are a consequence of aromatization to estrogen is not known. Despite the paucity of data regarding its effects, inclusion of testosterone in postmenopausal hormone replacement regimens is not uncommon and is likely to become more widespread with the availability of preparations developed specifically for women. Other novel and even more controversial potential indications for androgen therapy in women are currently being evaluated. These include use in women with premature ovarian failure, premenopausal androgen deficiency symptoms, postmenopausal and glucocorticosteroid-related bone loss, alleviation of wasting syndrome secondary to human immunodeficiency virus infection, and management of premenstrual syndrome. The aim of this commentary is to very briefly review the rationale for the use of testosterone in women, create awareness of some of the therapeutic options available in various countries, and stimulate discussion of this important aspect of women's health.
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431
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Davis S. Hormone replacement therapy. Indications, benefits and risk. AUSTRALIAN FAMILY PHYSICIAN 1999; 28:437-45. [PMID: 10376367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND The debate surrounding oestrogen replacement in peri and postmenopausal women has been made overly controversial by the dissemination of misinformation and subjective evaluation of available data both by proponents and opponents of such treatment. OBJECTIVE To review the indications, risks and benefits of oestrogen with and without progestin therapy in postmenopausal women. CONCLUSIONS When prescribed judiciously, such that undesirable side effects are avoided, many women well benefit overall from the use of oestrogen in the postmenopausal years. Clearly many of these benefits are long term in addition to providing acute symptomatic relief.
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432
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Davis S. Syndromes of hyperandrogenism in women. AUSTRALIAN FAMILY PHYSICIAN 1999; 28:447-51. [PMID: 10376368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND Although the actual incidence is not known, hyperandrogenism seems common among Australian women. Most women with syndromes of hyperandrogenism present with symptoms such as acne, hirsutism and androgenic alopecia, or menstrual irregularity. OBJECTIVES The aim of this overview is: to put in perspective the various causes of hyperandrogenism in women, provide a guide to evaluation of affected women; and briefly review current management strategies. DISCUSSION Hyperandrogenism in women is also associated with significant health problems including infertility, insulin resistance, gestational diabetes, type 2 diabetes mellitus and dyslipidaemia which may or may not be linked with obesity.
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Davis S. Another look at Civil War medical care: Atlanta's Confederate hospitals. JOURNAL OF THE MEDICAL ASSOCIATION OF GEORGIA 1999; 88:9-23. [PMID: 10341486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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435
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Snyder P, Anliker J, Cunningham-Sabo L, Dixon LB, Altaha J, Chamberlain A, Davis S, Evans M, Hurley J, Weber JL. The Pathways study: a model for lowering the fat in school meals. Am J Clin Nutr 1999; 69:810S-815S. [PMID: 10195607 PMCID: PMC4878706 DOI: 10.1093/ajcn/69.4.810s] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We describe the development and implementation of the Pathways school food service intervention during the feasibility phase of the Pathways study. The purpose of the intervention was to lower the amount of fat in school meals to 30% of energy to promote obesity prevention in third- through fifth-grade students. The Pathways nutrition staff and the food service intervention staff worked together to develop 5 interrelated components to implement the intervention. These components were nutrient guidelines, 8 skill-building behavioral guidelines, hands-on materials, twice yearly trainings, and monthly visits to the kitchens by the Pathways nutrition staff. The components were developed and implemented over 18 mo in a pilot intervention in 4 schools. The results of an initial process evaluation showed that 3 of the 4 schools had implemented 6 of the 8 behavioral guidelines. In an analysis of 5 d of school menus from 3 control schools, the lunch menus averaged from 34% to 40% of energy from fat; when the menus were analyzed by using the food preparation and serving methods in the behavioral guidelines, they averaged 31% of energy from total fat. This unique approach of 5 interrelated food service intervention components was accepted in the schools and is now being implemented in the full-scale phase of the Pathways study in 40 schools for 5 y.
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Valenzuela DM, Griffiths JA, Rojas J, Aldrich TH, Jones PF, Zhou H, McClain J, Copeland NG, Gilbert DJ, Jenkins NA, Huang T, Papadopoulos N, Maisonpierre PC, Davis S, Yancopoulos GD. Angiopoietins 3 and 4: diverging gene counterparts in mice and humans. Proc Natl Acad Sci U S A 1999; 96:1904-9. [PMID: 10051567 PMCID: PMC26709 DOI: 10.1073/pnas.96.5.1904] [Citation(s) in RCA: 335] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/1998] [Accepted: 12/18/1998] [Indexed: 01/14/2023] Open
Abstract
The angiopoietins have recently joined the members of the vascular endothelial growth factor family as the only known growth factors largely specific for vascular endothelium. The angiopoietins include a naturally occurring agonist, angiopoietin-1, as well as a naturally occurring antagonist, angiopoietin-2, both of which act by means of the Tie2 receptor. We now report our attempts to use homology-based cloning approaches to identify new members of the angiopoietin family. These efforts have led to the identification of two new angiopoietins, angiopoietin-3 in mouse and angiopoietin-4 in human; we have also identified several more distantly related sequences that do not seem to be true angiopoietins, in that they do not bind to the Tie receptors. Although angiopoietin-3 and angiopoietin-4 are strikingly more structurally diverged from each other than are the mouse and human versions of angiopoietin-1 and angiopoietin-2, they appear to represent the mouse and human counterparts of the same gene locus, as revealed in our chromosomal localization studies of all of the angiopoietins in mouse and human. The structural divergence of angiopoietin-3 and angiopoietin-4 appears to underlie diverging functions of these counterparts. Angiopoietin-3 and angiopoietin-4 have very different distributions in their respective species, and angiopoietin-3 appears to act as an antagonist, whereas angiopoietin-4 appears to function as an agonist.
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438
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Abstract
Simple models for the integration of a selectively neutral transgene into a feral population, by stocking of transgenic individuals, are developed. The impact of stocking individuals having multiple unlinked homozygous locations of the transgene is quantified. Initially it is assumed that there is no overlap between successive generations but a more general model for species having discrete overlapping generations is also developed. The primary application for this work is biological control. It is found that the integration of a transgene is considerably quickened by stocked transgenics carrying the transgene at multiple sites.
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Abstract
The importance of the role of an advanced practice nurse in infectious diseases has been heightened by the human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic. The unique abilities that are part of the expanded role enable the advanced practice nurse to utilize tools learned as a nurse and combine them with advanced clinical skills to be a comprehensive care provider. The clinical management of the patient with HIV is complex and requires up-to-date knowledge regarding the constantly changing science of the virus.
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Saddik D, Frazer C, Robins P, Reed W, Davis S. Gadolinium-enhanced three-dimensional MR portal venography. AJR Am J Roentgenol 1999; 172:413-7. [PMID: 9930794 DOI: 10.2214/ajr.172.2.9930794] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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441
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O'Brien B, Davis S, Erwin-Toth P. G-tube site care: a practical guide. RN 1999; 62:52-6. [PMID: 10086018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Effective care of your patient's gastrostomy site is key to her recovery--even after she's been discharged. Here we'll zero in on the prevention and treatment of skin problems and tube dislodgement, and review which anchoring device best suits your particular patient's needs.
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Latza U, Davis S, Wilhelm D, McKnight B, Seyfarth M, Stein H. Soluble cytokine receptor CD30 in atopic disorders: a case-control study. Clin Exp Allergy 1999; 29:97-104. [PMID: 10051708 DOI: 10.1046/j.1365-2222.1999.00450.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The cytokine receptor CD30 is an activation marker of T cells which preferentially associates with the production of the TH2 cytokine IL-4. Therefore, it may potentially be a candidate marker for atopic disorders and a target molecule for new therapeutic approaches. OBJECTIVE To test the hypothesis that elevated levels of soluble CD30 (sCD30) are significantly associated with atopic disorders after adjustment for other predictors of atopy. METHODS The presence of elevated sCD30 (> or = 20 U/mL) in atopic disorders was evaluated in a nested case-control study. Cases (n = 60) were blood donors with specific IgE antibodies, total serum levels of IgE > or = 100kU/L and presence or history of allergic symptoms. Controls (n = 59) were blood donors without presence or history of allergic symptoms and serum levels of IgE < 50 kU/L. sCD30 was determined from serum samples by an enzyme-linked immunosorbent assay. Odds ratios (OR) and confidence intervals (CI) were calculated from logistic regression coefficients. RESULTS Mean sCD30 levels for cases were 75 U/mL (SD 110U/mL) as compared with 35 U/mL (SD 59 U/mL) for controls. Serum levels of sCD30 were elevated in 65% of cases and 32% of controls (OR 3.9, 95% CI 1.8-8.4). The odds ratio for elevated sCD30 as a predictor of atopic disorders slightly decreased to 3.7 after controlling for smoking, age and gender. Blood eosinophilia which was a strong predictor of atopy (OR 11.7) was a weak confounder of the association between sCD30 levels and atopic disorders. Family history of allergy, another strong predictor of atopy (OR 8.6), did not confound the association. CONCLUSIONS The results are consistent with the hypothesis that CD30 is involved in the pathogenesis of atopic disorders independent of eosinophilia and family history of allergy.
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Wirth A, Chao M, Corry J, Laidlaw C, Yuen K, Ryan G, Byram D, Davis S, Kiffer J, Quong G, Liew K. Mantle irradiation alone for clinical stage I-II Hodgkin's disease: long-term follow-up and analysis of prognostic factors in 261 patients. J Clin Oncol 1999; 17:230-40. [PMID: 10458238 DOI: 10.1200/jco.1999.17.1.230] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To evaluate mantle radiotherapy (MRT) alone as the initial therapy of patients with clinical stage (CS) I-II Hodgkin's disease (HD). PATIENTS AND METHODS We performed a retrospective study of patients treated with MRT alone for CS I-II supradiaphragmatic HD between 1969 and 1994. Prognostic factor analysis was performed for progression-free survival (PFS) and overall survival (OS). Outcome was also assessed in favorable cohorts defined in the literature. RESULTS There were 261 eligible patients. The median follow-up period for surviving patients was 8.4 years (range, 1.8 to 27.4 years). The 10-year OS rate was 73%. Multifactor analysis for OS showed that age was the only important prognostic factor. The 10-year PFS rate was 58%. On multifactor analysis for PFS, the most important prognostic factors were clinical stage, B symptoms, histology, number of sites, and tumor bulk. The 10-year PFS rate for lymphocyte-predominant disease was 81% for stage I and 78% for stage II. In favorable patient cohorts defined in the literature, the 10-year PFS rate ranged from 70% to 73% for the whole group and from 71% to 90% in patients with favorable stage I disease, but only from 48% to 57% in patients with favorable stage II disease. On competing-risks analysis, the cumulative 10-year incidence of first site of failure in the para-aortic/splenic region alone was 10.5%. Sixty percent of relapsed patients remain progression-free at 10 years after chemotherapy salvage. CONCLUSION These results support the use of MRT alone in patients with favorable CS I HD and CS I-II HD with lymphocyte-predominant histology. The remainder of patients with CS I-II HD require more intensive treatment.
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445
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Grinspoon S, Corcoran C, Rosenthal D, Stanley T, Parlman K, Costello M, Treat M, Davis S, Burrows B, Basgoz N, Klibanski A. Quantitative assessment of cross-sectional muscle area, functional status, and muscle strength in men with the acquired immunodeficiency syndrome wasting syndrome. J Clin Endocrinol Metab 1999; 84:201-6. [PMID: 9920084 DOI: 10.1210/jcem.84.1.5375] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The acquired immunodeficiency syndrome wasting syndrome (AWS) in men is characterized by the loss of lean body mass out of proportion to weight. Although the wasting syndrome has been thought to contribute to reduced functional capacity, the relationships among lean body mass, muscle size, functional status, and regional muscle strength have not previously been investigated in this population. In this study, 24 eugonadal men with the AWS (weight <90% of the ideal body weight or weight loss >10% from preillness maximum) underwent determination of body composition by dual energy x-ray absorptiometry (DXA), 40K isotope analysis, urinary creatinine excretion, and quantitative computed tomographic analysis of cross-sectional muscle areas of the midarm and thigh. Overall exercise functional capacity was evaluated using the 6-min walk test, and performance of upper and lower extremities was determined with the quantitative muscle function test. Subjects were 37 +/- 1 yr of age and weighed 95.5 +/- 3.0% of ideal body weight, with a body mass index of 21.9 +/- 0.7 kg/m2 and an average weight loss of 15 +/- 1%. The mean CD4 count among the subjects was 354 +/- 70 cells/mm3, and viral load was 58,561 +/- 32,205 copies. Sixty-two percent of subjects were receiving protease inhibitor therapy. The subjects demonstrated 90% of the expected muscle mass by the creatinine height index method. Overall performance status on the Karnofsky scale was highly correlated to weight (r = 0.51; P = 0.018; by body mass index), lean body mass (r = 0.46; P = 0.036; by DXA), and body cell mass (r = 0.47; P = 0.037; by 40K isotope analysis). Cross-sectional muscle area of the upper extremity was the best predictor (P < 0.001) of Karnofsky score, accounting for 52% of the variability in a stepwise regression analysis. Upper body muscle strength was most significantly predicted by lean body mass (by DXA; r2 = 0.78; P < 0.0001), whereas lower body strength and performance on the 6-min walk test were best predicted by lower extremity cross-sectional muscle area (r2 = 0.70; P < 0.0001 and r2 = 0.26; P = 0.030, respectively). These data demonstrate that cross-sectional muscle area is highly predictive of functional status and muscle strength in men with the AWS.
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Dignan MB, Michielutte R, Wells HB, Sharp P, Blinson K, Case LD, Bell R, Konen J, Davis S, McQuellon RP. Health education to increase screening for cervical cancer among Lumbee Indian women in North Carolina. HEALTH EDUCATION RESEARCH 1998; 13:545-556. [PMID: 10345905 DOI: 10.1093/her/13.4.545] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Although age-adjusted mortality rates from cancer among Native-Americans are generally lower than for the US population as a whole, cervical cancer mortality rates are higher. This report presents results from a National Cancer Institute-funded health education program conducted among the Lumbee tribe in North Carolina that was designed to increase the proportion of women, age 18 and older, who receive Pap smears to screen for cervical cancer. The Solomon Four Group research design was used for this project. Participants were selected at random from the enrollment records of the Lumbee tribe and data collection was carried out during face-to-face interviews. The health education program was provided one-on-one in women's homes by a trained lay health educator and included verbal, print and videotape information. A total of 979 women were enrolled in the study, and 125 were lost to follow-up between the pre-test and post-test. Women who received the education program were found to be more likely to have knowledge of the Pap smear and to report a Pap smear in the past year at the post-test than those in the control group, regardless of whether they received the pre-test interview, P < 0.05. Women most likely to respond to the education program were also likely to have reported that they receive an annual physical examination. Women with better knowledge of the Pap smear tended to have more education, higher income and greater identification with Native-American culture than those with less knowledge. We conclude that the health education program was associated with greater knowledge about cervical cancer prevention and higher proportions of Lumbee women obtaining Pap smears in the past year.
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Bielec P, Gallagher D, Womack J, Taylor J, Davis S, Busbee D. Dolphin interleukin-8 receptor. Map position 18q25-26. Chromosome Res 1998; 6:661. [PMID: 10099883 DOI: 10.1023/a:1009278131934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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449
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Lesitsky MA, Davis S, Murray PA. Preservation of hypoxic pulmonary vasoconstriction during sevoflurane and desflurane anesthesia compared to the conscious state in chronically instrumented dogs. Anesthesiology 1998; 89:1501-8. [PMID: 9856726 DOI: 10.1097/00000542-199812000-00029] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The authors' objective was to assess the extent to which sevoflurane and desflurane anesthesia alter the magnitude of hypoxic pulmonary vasoconstriction compared with the response measured in the same animal in the conscious state. METHODS Left pulmonary vascular pressure-flow plots were generated in seven chronically instrumented dogs by continuously measuring the pulmonary vascular pressure gradient (pulmonary arterial pressure-left atrial pressure) and left pulmonary blood flow during gradual (approximately 1 min) inflation of a hydraulic occluder implanted around the right main pulmonary artery. Pressure-flow plots were generated during normoxia and hypoxia on separate days in the conscious state, during sevoflurane (approximately 3.5% end-tidal), and during desflurane (approximately 10.5% end-tidal) anesthesia. Values are mean+/-SEM. RESULTS In the conscious state, administration of the hypoxic gas mixture by conical face mask decreased (P < 0.01) systemic arterial PO2 from 94+/-2 mmHg to 50+/-1 mmHg and caused a leftward shift (P < 0.01) in the pressure-flow relationship, indicating pulmonary vasoconstriction. The magnitude of hypoxic pulmonary vasoconstriction in the conscious state was flow-dependent (P < 0.01). Neither anesthetic had an effect on the baseline pressure-flow relationship during normoxia. The magnitude of hypoxic pulmonary vasoconstriction during sevoflurane and desflurane was also flow-dependent (P < 0.01). Moreover, at any given value of flow the magnitude of hypoxic pulmonary vasoconstriction was similar during sevoflurane and desflurane compared with the conscious state. CONCLUSION These results indicate that hypoxic pulmonary vasoconstriction is preserved during sevoflurane and desflurane anesthesia compared with the conscious state. Thus, inhibition of hypoxic pulmonary vasoconstriction is not a general characteristic of inhalational anesthetics. The flow-dependent nature of the response should be considered when assessing the effects of physiologic or pharmacologic interventions on the magnitude of hypoxic pulmonary vasoconstriction.
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Graesser D, Mahooti S, Haas T, Davis S, Clark RB, Madri JA. The interrelationship of alpha4 integrin and matrix metalloproteinase-2 in the pathogenesis of experimental autoimmune encephalomyelitis. J Transl Med 1998; 78:1445-58. [PMID: 9840619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Previous studies have suggested that surface expression of alpha4 integrin by autoreactive T-cell clones is necessary for the clones to induce experimental autoimmune encephalomyelitis (EAE), a mouse model for human multiple sclerosis. To provide direct evidence for this phenomenon, we have transfected alpha4 integrin into C19alpha4-LO, a myelin basic protein-reactive T-cell clone that does not express alpha4 integrin and does not induce EAE when adoptively transferred into a susceptible mouse strain. Transfection of alpha4 integrin converted this clone to an alpha4 integrin-expressing clone that induced EAE. We then examined potential mechanisms by which alpha4 integrin may facilitate the disease process. C19 T-cell clones adhered equally to a monolayer of microvascular endothelial cells, regardless of level of alpha4 integrin expression. However, in contrast to T-cell clones that do not express alpha4 integrin, T-cell clones that express alpha4 integrin (endogenously or by transfection) transmigrated through an endothelial cell layer and subendothelial matrix at an enhanced rate and adhered to recombinant vascular cell adhesion molecule-1 (rVCAM-1) and the CS1 fragment of fibronectin, and after adhesion to these ligands, a matrix-degrading metalloproteinase (MMP-2) was induced and activated. The clones were also shown to constitutively express the membrane-type matrix metalloproteinase (MT1-MMP), an enzyme that activates MMP-2. GM6001 and UK-221,316, inhibitors of metalloproteinases, reduced alpha4 integrin-mediated transmigration and EAE induction by C19 T-cell clones. In addition, we studied a second EAE-inducing T-cell clone, MM4, which constitutively expresses alpha4 integrin and MMP-2. Engagement of alpha4 integrin on the MM4 clone up-regulated the expression and activation of MMP-2, without changing the expression of MT1-MMP. MMP inhibitors also reduced transmigration of and EAE induction by the MM4 T-cell clone. These studies demonstrate directly that expression of alpha4 integrin by autoreactive T-cell clones is required for adoptive transfer of EAE in this model. We also define a role for alpha4 integrin in the disease process in mediating the induction and coordinate activation of a matrix metalloproteinase (MMP-2), which facilitates T-cell transmigration.
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