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Biomedical subjects

A Long

Publications and source records attributed to A Long.

At least 55 records · Page 3Linked to original sources
PubMed2000

The influence of mucus on copper speciation in the gill microenvironment of carp (Cyprinus carpio).

pH and mucus (as total organic carbon) in the gill microenvironment of carp, Cyprinus carpio, exposed to various concentrations of total copper were measured in an exposure experiment using Playle's apparatus. The activities of free copper ions in both inspired and expired waters were determined using a copper ion selective electrode. A trial-and-error procedure of coupling species distribution calculations (MINEQA2) with single-site complexation modeling (mucus-copper) was proposed for computation of both copper speciation and complexation capacity of gill mucus for copper in an interactive loop. The method was demonstrated to be valid in calculating the metal speciation in this study. It was found that pH and alkalinity in the gill microenvironment were slightly higher than in the surrounding water of pH 6.7. The rates of excretion of CO(2), HCO(-)(3), and mucus at the gills increased, either linearly or nonlinearly with increases in the total copper concentration in the surrounding water. The conditional complexation stability constant of the mucus was calculated as log k=5.32, while the complexation stability equivalent concentration of the mucus was derived as 0.95 mmolCu/mgC. As a consequence of changes in pH and alkalinity, in conjunction with occurrence of mucus, copper speciation in the gill microenvironment is significantly different from that in the surrounding water, with 3-20% of the copper complexed by the gill mucus. The sequence of species domination also shifted from CuCO(0)(3), Cu(2+), CuHCO(+)(3), and Cu(OH)(0)(2) in the surrounding water to CuCO(0)(3), Cu(2+), Cu(OH)(0)(2), CuHCO(+)(3), and mucus-Cu in the gill microenvironment.

Animals↗
PubMed2000

Uptake of cadmium adsorbed on particulates by gills of goldfish (Carassius auratus).

Goldfish (Carassius auratus) were exposed to mixtures of constant dissolved cadmium (0.01 mg/L) and cadmium adsorbed on gibbsite particles at concentrations of 0, 0.025, 0.050, 0.075, and 0.100 mg/L. The gills of the fish were excised after a 5-day exposure experiment and both cadmium and aluminum in the gills were measured. The gills were also examined with a light microscope for surface adherence of the particles after the exposure. The evidence collected demonstrated that the concentration of cadmium in the gills increased with increased concentration of particulate cadmium during the exposure while the dissolved cadmium remained constant. The ratio of cadmium to aluminum in the gills was apparently higher than that in the solution, indicating the stripping and translocation of cadmium from the particles. A multistep uptake process is proposed and the bioavailability of particulate cadmium to fish gills is discussed.

Adsorption↗
PubMed2000

High multidrug resistance (P-glycoprotein 170) expression in inflammatory bowel disease patients who fail medical therapy.

BACKGROUND & AIMS: The multidrug resistance (MDR) gene codes for a drug efflux pump P-glycoprotein 170 (Pgp-170) expressed on the surface of lymphocytes and intestinal epithelial cells. Inflammatory bowel disease (IBD) poorly responsive to medical therapy may relate to MDR expression because glucocorticoids are known Pgp-170 substrates. METHODS: Using flow cytometry, we measured peripheral blood lymphocyte (PBL) MDR in 153 IBD patients and 50 healthy volunteers, and assessed the relationship between PBL, mucosal intraepithelial lymphocyte (IEL), and mucosal epithelial cell (EC) MDR expression in a further 20 IBD patients and 19 controls. RESULTS: Compared with controls, PBL MDR was significantly elevated in patients with Crohn's disease who required bowel resection for failed medical therapy (mean +/- SEM, 26.7 +/- 2.8 vs. 11.9 +/- 1.0; P <0.0001) and patients with ulcerative colitis who required proctocolectomy for failed medical therapy (20.3 +/- 2.5 vs. 11.9 +/- 1.0; P = 0.001). PBL MDR remained stable over time and was not influenced by disease activity or glucocorticoid therapy. Both PBL and mucosal MDR expression appeared independent of disease activity, and there was a significant correlation between PBL MDR expression and both IEL expression (r = 0.92; P < 0.0001) and EC expression (r = 0.54; P < 0.001). CONCLUSIONS: PBL and mucosal MDR expression may play an important role in determining the response of IBD patients to glucocorticoid therapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Role of vegetable tannins in habitat selection among mosquito communities from the Alpine hydrosystems.

The role of vegetable tannins in habitat selection among mosquito communities in Alpine hydrosystems was investigated through ecotoxicological comparison of 19 arthropod species characteristic of 12 breeding sites known for their abiotic environmental factors and their different riparian vegetation. The toxicity of tannins was experimentally compared among species representative of both the dipteran fauna and the crustacean fauna associated with the mosquito breeding sites. Bioassays using tannic acid solutions at concentrations from 0.1 to 11 mM separated the dipteran taxa into five groups of differential sensitivity and the crustacean taxa into four groups. The different levels of sensitivity among taxa were correlated with the various amounts of total phenolics and tannins found in the most prominent plant types associated with the different breeding sites. This suggested that tannins and, more generally, phenolic compounds may be involved in plant-arthropod interactions in Alpine hydrosystems.

Animal Feed↗
PubMed2000

The labyrinth of health as perceived by two groups of community nurses.

The purpose of this research was to examine a group of 16 health visitors and a group of 16 community mental health nurses perceptions of health and health awareness. The study was mainly qualitative and exploratory in nature with some quantitative data being collected to condense the data. All 32 respondents were interviewed using a semistructured, tape recorded format. The content of the data was scrutinized and emerging patterns, themes, and concepts were noted and coded using a tried and tested theoretical process. The findings were related to the questions asked and comparisons were drawn between the information received from each group. An examination of the data revealed that the group of health visitors defined health terms of 'functional' states, described health in physical terms, and practiced physical exercises as their health valuing behaviours in order to keep themselves healthy. This key theme also emerged with reference to their value of health at family and global levels. Taking their health for granted and being grateful for it when they saw someone in the community less well off than themselves was also highlighted as a major theme. The group of community mental health nurses defined their health in 'being' states and described health in a holistic manner. They perceived the value and concept of 'freedom' to be related to and embraced within the concept, definition and value of health at individual, family and global levels. They practiced aesthetic health valuing behaviours to enhance their appreciation of health and self. Mental health, the ability to make choices, being self actualizing and the capacity to love and be loved were the key themes emerging throughout this group's responses. It would be interesting to develop this research from a community health perspective.

Attitude of Health Personnel↗
PubMed2000

Colon signet ring cell adenocarcinoma: immunohistochemical characterization and comparison with gastric and typical colon adenocarcinomas.

Colon signet ring cell adenocarcinomas are uncommon, high-grade neoplasms. Given their rarity, the question of primary colon or metastatic gastric adenocarcinoma frequently arises when signet ring cell carcinoma is seen in a colonoscopic biopsy or in biopsies procured from other regions of the body. A second related question regarding colon and gastric signet ring cell carcinomas is their immunophenotypic similarities with the glandular form of adenocarcinoma in each site. We studied the immunohistochemical phenotype of 14 colonic signet ring cell adenocarcinomas and compared them with immunophenotype of 27 gastric signet ring cell adenocarcinomas. We also compared the immunophenotype of the 27 gastric signet ring cell with the immunophenotype of 19 gastric gland-forming adenocarcinomas, and the immunophenotype of the 14 colonic signet ring cell adenocarcinomas to the immunophenotype of 20 colonic gland-forming adenocarcinomas to identify staining differences in the neoplastic cells of the two architectures. Antibodies studied were cytokeratins 7, 17, 19, and 20, CA 19-9, CA-125. estrogen receptor, and gross cystic disease fluid protein 15. Sixty-four percent of colon signet ring cell adenocarcinomas had either no staining or focal staining with cytokeratin 7 compared with diffuse staining in 63% of gastric signet ring cell adenocarcinomas (P = 0.016). Seventy-two percent of colon signet ring cell adenocarcinomas had diffuse staining with cytokeratin 20 compared with no or focal staining in 50% of gastric signet ring cell adenocarcinomas (P = 0.019). Fifty-seven percent of the colon signet ring cell adenocarcinomas had a cytokeratin 7 (-)/cytokeratin 20 (+) staining pattern compared with 11% of gastric signet ring cell adenocarcinomas (P = 0.004). Forty-four percent of gastric signet ring cell adenocarcinomas had a cytokeratin 7 (+)/cytokeratin 20 (-) pattern, compared with none of the colon signet ring cell adenocarcinomas (P = 0.004). The staining distribution of the antibody battery was similar in colon signet ring cell and colon glandular adenocarcinoma and gastric signet ring cell and gastric glandular adenocarcinomas. When signet ring cell adenocarcinoma is encountered in a colon biopsy, a colon primary is supported if the neoplastic cells have a cytokeratin 7 (-)/cytokeratin 20 (+) staining pattern, and a gastric primary is supported if they have a cytokeratin 7 (+)/cytokeratin 20 (-) staining pattern. The signet ring morphology at each site had an identical immunophenotype as the cells forming their glandular counterpart.

Adenocarcinoma↗
PubMed2000

Hepatitis C lookback in Canada.

BACKGROUND AND OBJECTIVES: Since March 1990, all blood donations in Canada are screened by enzyme-linked immunosorbent assay (EIA) for antibodies to HCV, with confirmatory testing done using a recombinant immunoblot assay (RIBA). Because HCV may cause chronic asymptomatic hepatitis, in 1995, the Canadian Red Cross began targeted HCV lookback studies on all confirmed positive donations. These have been continued by the two new operators of the blood system in Canada, Héma-Québec and the Canadian Blood Services. Subsequent to recommendations made in the public inquiry into the Canadian blood system, led by judge Krever, general lookback through letter notification of all patients transfused in the years prior to the introduction of anti-HCV testing was initiated in several pediatric hospitals, and later in several Canadian provinces. MATERIALS AND METHODS: Targeted HCV lookback was done for all donors confirmed positive by RIBA testing from the start of HCV testing in 1990. In 1999, stored RIBA 2 indeterminate samples were re-tested by RIBA 3, and lookback performed on confirmed positive donations. In the province of Quebec, hospitals were surveyed to determine methods and resources involved in lookback. Provinces performing general letter notification entered hospital transfusion records into a central transfusion data bank, and performed linkage with other provincial data banks to remove deceased patients and obtain current addresses. RESULTS: As of January 2000, targeted lookback had been completed on 4,859 components of 1,628 anti-HCV positive repeat donors. 2,991 recipients were deceased, and 451 were not found or tested. Of the 1,422 recipients tested, 954 (67%) were anti-HCV positive. Approximately half were already aware of their HCV status. Lookback efforts in hospitals were hampered by lack of resources and manual records. General letter notification in British Columbia (BC) and Prince Edward Island (PEI) led to the testing of 38,960 and 1,953 recipients respectively, with 5.0 and 2.2% of tested recipients found to be anti-HCV positive. CONCLUSION: In completed targeted lookback investigations, 19% of components are eventually linked to an anti-HCV positive recipient. These results are very similar to those obtained in other countries, such as Denmark and the UK. In general letter notification lookbacks, the frequency of anti-HCV in the tested recipients is approximately twice the frequency of the general population.

Antibodies, Viral↗
PubMed2000

[Abdominal aortic aneurysm repair treated with endoprosthesis: technical and economic evaluation by ANAES(National Agency of Health Accreditation and Evaluation)].

OBJECTIVE: To evaluate the safety, efficacy and cost of stent-grafts for the endovascular repair of abdominal aortic aneurysms (AAA). MATERIALS AND METHODS: The ANAES report was based on a critical analysis of the published international literature and on consultation of technology assessment agencies. The report was reviewed by a group of experts and validated by the ANAES Scientific Council (Evaluation Section). RESULTS: The literature analysis indicated that the technique was feasible. However, it also revealed a shortage of methodologically sound clinical trials. The long-term outcome of the stent-grafts and the accompanying complications are not yet known. CONCLUSION: Further clinical studies are needed for a truly objective assessment. The ANAES working group has issued a series of recommendations designed to help physicians define the optimal conditions for the effective and safe use of these stent-grafts.

Aortic Aneurysm, Abdominal↗
PubMed1999

High-risk sexual behavior in Los Angeles: who receives testing for HIV?

No recent population-based data on HIV testing in people with high-risk sexual behavior are available. We sought predictors of testing using data from the 1997 Los Angeles County Health Survey, a random-digit telephone survey of 8004 county households. An estimated 2.3 million (35.5%) adults were tested for HIV in the past 2 years and approximately 370,000 (5.6%) engaged in high-risk sexual behavior (defined as having > or =2 partners in the past 12 months and not always using condoms). Among high-risk persons, an estimated 46% of heterosexual men, 56% of heterosexual women, and 72% of men who had sex with men (MSM) were tested for HIV. In a multivariable model of high-risk people, both heterosexual men (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.16-0.61) and women (OR, 0.41; 95% CI, 0.19-0.87) had significantly lower proportions of testing than MSM. Although African Americans and Hispanics had significantly higher testing proportions than whites overall among all county residents, those reporting high-risk sexual behavior did not test at higher proportions. We conclude that the proportion of adults with high-risk sexual behavior tested for HIV is higher than almost a decade ago. However, testing among this group remains suboptimal. Future public health campaigns should intensify efforts to encourage HIV testing among this population.

AIDS Serodiagnosis↗
PubMed1999

Transient myocardial dysfunction associated with angiotensin-converting enzyme inhibitor-induced angioedema: recognition by serial echocardiographic studies.

We report a case of a 58-year-old woman who had angiotensin converting enzyme inhibitor-induced angioedema after she underwent a biopsy of a hypopharyngeal mass. The angioedema was associated with severe transient myocardial dysfunction documented on echocardiography. She did not have anaphylaxis or coronary artery disease. To our knowledge this is the first reported case of transient myocardial dysfunction in the setting of angiotensin converting enzyme inhibitor-induced angioedema without anaphylaxis.

Angioedema↗
PubMed1999

Targeted hepatitis C lookback: Quebec, Canada.

BACKGROUND: Since March 1990, all blood donations in Canada are screened for antibodies to hepatitis C virus (HCV). Because HCV may cause chronic asymptomatic hepatitis, in February 1995, the Canadian Red Cross began targeted HCV lookback studies. STUDY DESIGN AND METHODS: From March 1990 to March 1997, the Quebec Center of the Canadian Red Cross collected 1,750,846 donations, and there were 561 anti-HCV-positive repeat donors, from whom 3,196 blood components had been issued to the hospitals. Hospital blood bank directors were asked to test recipients and return results to the Quebec Center. One hundred nine hospitals were surveyed to determine methods and resources involved in lookback. The transfusion medicine service at the Royal Victoria Hospital (RVH) developed a standard operating procedure for performing lookbacks and analyzed the costs and outcomes of lookbacks. RESULTS: As of April 1998, information has been received on 2329 (73%) of components; 1020 patients had died of unrelated causes, 590 were untraceable, and 353 were tested. Of those tested, 215 (61%) were anti-HCV positive; their average age was 47, and at least 53 percent were already aware of their HCV status. Few hospitals had received any additional resources to perform lookbacks. At the RVH, lookback on 182 components resulted in the identification of nine seropositive recipients, average age 70, who did not previously know their HCV status; four of these patients had abnormal alanine aminotransferase levels. The cost of lookback per newly diagnosed case of HCV was estimated at $2727 (US) for the Quebec Center and $6014 (US) for the RVH. CONCLUSION: Targeted lookback in the province of Quebec on 3196 components has resulted in the identification of 101 seropositive recipients who did not previously know their HCV status.

Blood Banks↗
PubMed1999

Living with dementia: communicating with an older person and her family.

This article is designed to explore and examine the key components of communication that emerged during the interactional analysis of a role play that took place in the classroom. The 'actors' were nurses who perceived the interaction to reflect an everyday encounter in a hospital ward. Permission to tape the interaction was sought and given by all persons involved. The principal 'players' in the scenario were: the patient, a 70-year-old-woman who had been admitted with dementia, her son and daughter, and the nurse in charge of the ward. The fundamental dynamics of the use of power and restriction, truth telling, family stress, interpersonal conflict, ageism, sexism, empathy and humanism surfaced during the analysis. The findings show that therapeutic communication should be the foundation on which nursing should stand. The article continues with an exploration of the theoretical frameworks that guided the analysis of interaction and concludes by suggesting tentatively some meaningful implications for nursing practice. It plans to furnish provocative new insights into the sometimes covert communication dynamics occurring within the nurse-patient relationship. Finally, it aims to generate discussion on this little-charted realm of human social interaction.

Adaptation, Psychological↗