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Biomedical subjects

D Weir

Publications and source records attributed to D Weir.

At least 19 recordsLinked to original sources

Genome sequence of Halobacterium species NRC-1.

We report the complete sequence of an extreme halophile, Halobacterium sp. NRC-1, harboring a dynamic 2,571,010-bp genome containing 91 insertion sequences representing 12 families and organized into a large chromosome and 2 related minichromosomes. The Halobacterium NRC-1 genome codes for 2,630 predicted proteins, 36% of which are unrelated to any previously reported. Analysis of the genome sequence shows the presence of pathways for uptake and utilization of amino acids, active sodium-proton antiporter and potassium uptake systems, sophisticated photosensory and signal transduction pathways, and DNA replication, transcription, and translation systems resembling more complex eukaryotic organisms. Whole proteome comparisons show the definite archaeal nature of this halophile with additional similarities to the Gram-positive Bacillus subtilis and other bacteria. The ease of culturing Halobacterium and the availability of methods for its genetic manipulation in the laboratory, including construction of gene knockouts and replacements, indicate this halophile can serve as an excellent model system among the archaea.

Biological Evolution↗

Lansoprazole is superior to ranitidine as maintenance treatment for the prevention of duodenal ulcer relapse.

AIM: To compare lansoprazole 30 mg once daily, lansoprazole 15 mg once daily and ranitidine 150 mg once nightly in the prevention of duodenal ulcer relapse in patients whose duodenal ulcers had been previously healed with lansoprazole 30 mg once daily or ranitidine 300 mg nightly. METHODS: A double-blind, parallel group, randomized multicentre study conducted in 33 centres in the UK, Eire, Sweden and Australia. Two hundred and nineteen patients with a duodenal ulcer were randomized to receive lansoprazole 30 mg and 217 to receive ranitidine 300 mg for 8 weeks. Patients were then re-randomized to receive lansoprazole 30 mg (122 patients), lansoprazole 15 mg (121 patients) or ranitidine 150 mg (116 patients) for 12 months. All patients had an endoscopically-proven duodenal ulcer at baseline and were considered suitable for long-term maintenance therapy to prevent relapse. RESULTS: Significantly more patients were healed on lansoprazole (98%) compared to ranitidine (89%) (P < 0.001, Fisher's exact test). Lansoprazole provided more rapid symptom relief than ranitidine. Lansoprazole 30 mg and lansoprazole 15 mg increased the probability of not relapsing in comparison to ranitidine (P = 0.001 and 0.06, respectively, life-table analysis). Relapse rates over the 12 months were lower in the lansoprazole treatment groups (lansoprazole 30 mg, 5%; lansoprazole 15 mg, 12%; and ranitidine, 21%; lansoprazole 30 mg vs. ranitidine 150 mg, P = 0.002). Symptoms were well controlled in both groups during the maintenance phase. All treatments were well tolerated with no major differences seen in adverse event profiles between treatment groups. CONCLUSIONS: Both doses of lansoprazole (30 mg and 15 mg) were superior to ranitidine 150 mg in the prevention of duodenal ulcer relapse. Lansoprazole was superior to ranitidine in terms of symptom control and duodenal ulcer healing. Both treatments were well tolerated.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Carriage of Neisseria meningitidis and Neisseria lactamica among ethnic Greek school children from Russian immigrant families in Athens.

During February and March 1995, a survey of meningococcal carriage in 625 school children was carried out in a suburb of Athens in which there was a large number of ethnic Greeks who had immigrated from Russia beginning in the early 1990s. The objectives of the study were: (1) to determine if factors associated with carriage of meningococci observed in a previous study of Greek school children were similar for the immigrant population; (2) to compare phenotypic characteristics of meningococci from the immigrant population with those isolated from children in Athens. Overall isolation rate for meningococci was 82/625 (13.1%), significantly higher than that found for school children in Athens (5.8%) during the winter of 1990 1991 (5.8%) (chi=25.98, P=0.0000003). By univariate analysis, carriage was not associated with sex, number of individuals per household, blood group, secretor status, socioeconomic level or maternal smoking; however, it was associated with fathers' smoking. The high proportion of men who smoked compared with the low proportion of women smokers might contribute to this finding. The main serogroup of meningococci isolated from this population was A (28%). While serogroup A appears to be more prevalent among Russian and Kurdish immigrants (14%) than among Greek school children or military recruits (4%), there has not been an increase in group A meningococcal disease in Greece. The isolation rate for N. lactamica was high 105/625 (17.3%). A few of these strains bound some of the monoclonal antibodies used for meningococcal serotyping and subtyping, and they are being examined in greater detail.

Adolescent↗

Increased HLA-DR and CD44 antigen expression in the gut: evidence of extraarticular immunological activity in rheumatoid arthritis.

OBJECTIVE: To examine the gastrointestinal (GI) immune system in rheumatoid arthritis (RA) for evidence of activation. METHODS: Duodenal biopsies from 25 patients with RA were obtained by endoscopy. Single cell suspensions from the epithelial layer and lamina propria were prepared. Flow cytometry was used to examine the expression of CD4, CD8, T cell receptor-gammadelta (TCR-gammadelta), TCR-alphabeta, HLA-DR, CD44, and interleukin 2 receptor on gut T lymphocytes. Fifteen disease control (DC) individuals and 6 patients with osteoarthritis (OA) taking longterm nonsteroidal antiinflammatory drug (NSAID) therapy were also investigated. Peripheral blood T lymphocytes from all individuals were examined for the expression of these surface molecules. RESULTS: HLA-DR expression was significantly increased on intraepithelial lymphocytes (IEL) and enterocytes from patients with RA (n = 13) compared with the 2 control groups (p<0.01). Immunohistochemistry also revealed increased expression of HLA-DR on enterocytes from patients with RA. RA IEL (n = 6) expressed significantly higher levels of CD44 (p<0.02). In the lamina propria, a small but significant gammadelta T lymphocyte population (mean 5.5%, range 2-12%) was detected in rheumatoid factor positive RA patients (n = 8) compared with RF negative RA patients (n = 8, mean 2%, range 0.4-6%; p<0.01) and the disease control group (n = 15, mean 2%, range 0.5-5%; p<0.01). None of these changes were detectable in peripheral blood lymphocytes from patients with RA. CONCLUSION: This study demonstrates evidence of activation of specific components of the GI immune system in RA. Peripheral blood T lymphocytes from patients with RA did not show increased expression of activation markers, suggesting that changes in the RA GI tract are not systemic but localized. Moreover, these changes appear to be independent of NSAID therapy.

Adult↗

Perceived social support and community adaptation in schizophrenia.

Prompted by the continuing transition to community care, mental health nurses are considering the role of social support in community adaptation. This article demonstrates the importance of distinguishing between kinds of social support and presents findings from the first round data of a longitudinal study of community adaptation in 156 people with schizophrenia conducted in Brisbane, Australia. All clients were interviewed using the relevant subscales of the Diagnostic Interview Schedule to confirm a primary diagnosis of schizophrenia. The study set out to investigate the relationship between community adaptation and social support. Community adaptation was measured with the Brief Psychiatric Rating Scale (BPRS), the Life Skills Profile (LSP) and measures of dissatisfaction with life and problems in daily living developed by the authors. Social support was measured with the Arizona Social Support Interview Schedule (ASSIS). The BPRS and ASSIS were incorporated into a client interview conducted by trained interviewers. The LSP was completed on each client by an informal carer (parent, relative or friend) or a professional carer (case manager or other health professional) nominated by the client. Hierarchical regression analysis was used to examine the relationship between community adaptation and four sets of social support variables. Given the order in which variables were entered in regression equations, a set of perceived social support variables was found to account for the largest unique variance of four measures of community adaptation in 96 people with schizophrenia for whom complete data are available from the first round of the three-wave longitudinal study. A set of the subjective experiences of the clients accounted for the largest unique variance in measures of symptomatology, life skills, dissatisfaction with life, and problems in daily living. Sets of community support, household support and functional variables accounted for less variance. Implications for mental health nursing practice are considered.

Adaptation, Psychological↗

Quality of life during acute and intermittent treatment of gastro-oesophageal reflux disease with omeprazole compared with ranitidine. Results from a multicentre clinical trial. The European Study Group.

AIMS: To investigate quality of life in patients with gastro-oesophageal reflux disease. PATIENTS: A series of 704 patients were randomised to treatment with ranitidine 150 mg bd, omeprazole 10 mg om or omeprazole 20 mg om for 2 weeks. Asymptomatic/mildly symptomatic patients were followed for 12 months. METHODS: The Psychological General Well-Being index and the Gastrointestinal Symptom Rating Scale were completed before and during short-term and intermittent treatment. RESULTS: The quality of life response rate was > 80%. The majority of the patients receiving omeprazole 20 mg om (55%) had symptom relief after 2 weeks despite the fact that more patients on ranitidine required 4 weeks' treatment and an increased dose. There was no difference in the reflux dimension of Gastrointestinal Symptom Rating Scale between treatments in the initial treatment phase, but the total Gastrointestinal Symptom Rating Scale score improved significantly more on omeprazole 10 mg om than on ranitidine 150 mg bd (p = 0.006). Both doses of omeprazole improved the total Psychological General Well-Being score more than ranitidine (omeprazole 10 mg om versus ranitidine 150 mg bd, p = 0.005, omeprazole 20 mg om versus ranitidine 150 mg bd, p = 0.031). During follow-up, relapsing patients returned to pre-treatment symptom and well-being scores, but these dimensions were restored after treatment. CONCLUSION: The quality of life is impaired in patients presenting with reflux symptoms. Irrespective of whether the patients presented with endoscopy positive or endoscopy negative reflux disease, treatment on demand improved the quality of life.

Adolescent↗

Recommendations for using reverse staging to complete the MDS-2.

The use of the Minimum Data Set (MDS) for documentation in long term care has resulted in the widespread reliance on reverse staging to document the healing of pressure and venous ulcers. This article presents a pragmatic approach for defining the healing process in a staging nomenclature so that it is physiologically accurate.

Centers for Medicare and Medicaid Services, U.S.↗

Human umbilical vein endothelial cells: a new easily available source of endomysial antigens.

OBJECTIVE: To evaluate human umbilical vein endothelial cells (HUVEC) as an alternative source of endomysial antigen (EmAg) and to assess their suitability for the detection of endomysial antibodies (EmA) in coeliac disease (CD). METHODS: HUVEC were reacted on glass slides with patient sera and examined by fluorescent microscopy. Flow cytometry was used to determine whether the EmAg was expressed on the surface of the cells or was intracellular. Absorption studies were used to confirm the specificity of results. RESULTS: The data presented here show that HUVEC contain an intracellular antigen that binds to immunoglobulin A (IgA) from patients with active CD. Correlation studies showed that HUVEC antibodies were present in the sera of all patients that contained EmA and reticulin IgA antibodies whereas reticulin antibodies were only present in 24 of the 31 patients who were either EmA or HUVEC positive. All of the sera tested which were negative for EmA were also negative for HUVEC antibodies. Ten patients with Crohn's disease and 10 patients with ulcerative colitis were negative for HUVEC or EmA reactivity, as were 16 control subjects attending the gastroenterology clinic with non-specific symptoms and normal small intestinal biopsies. CONCLUSIONS: These findings suggest that the antigen found in HUVEC is antigenically similar to that found in reticulin and endomysium and that all three antigens may be the same. In contrast to the monkey oesophagus, HUVEC offer an easily available antigen for the serological diagnosis of coeliac disease.

Antibodies, Anti-Idiotypic↗

Chemotherapy with vincristine/ifosfamide/carboplatin/etoposide in small cell lung cancer.

Although chemotherapy is considered the cornerstone of treatment for small cell lung cancer (SCLC), the majority of SCLC patients relapse and die of their disease within 2 years of diagnosis. Until newer, more effective drugs are developed, both optimization of available chemotherapeutic regimens and the use of combined chemotherapy/radiotherapy will be required to improve the survival of SCLC patients. Combining ifosfamide, carboplatin, and etoposide, among the most active single agents against SCLC, into the ICE regimen was a logical move that has resulted in improved response and survival rates. In limited and extensive SCLC, respectively, ICE and ICE administered with vincristine (VICE) have achieved overall response rates of 79% to 94% and 77% to 100% and 2-year survival rates of 24% to 33% and 9% to 25%, respectively. Treatment-related toxicities, especially myelosuppression, have hindered efforts to accelerate the administration of ICE and VICE regimens and to incorporate them into combined-modality treatments. However, the use of hematologic support measures, including growth factors and peripheral blood progenitor cells, may pave the way for maximizing the effectiveness of these regimens.

Antineoplastic Combined Chemotherapy Protocols↗

Perceptions of stressors and reported coping strategies in nurses caring for residents with Alzheimer's disease in a dementia unit.

A study was undertaken on the perceptions of stressors and coping behaviours in a group of nurses caring for residents with Alzheimer's disease in a dementia unit. The purpose of this paper is to report on the preliminary findings of the study. Repertory grid data were used to explore how nurses perceive residents, the stressors nurses experience in their work, and the coping strategies nurses use when caring for residents. The nurses identified 92 sources of stress, 683 coping behaviours and 708 coping strategies. Analyses of selected repertory grid data are presented and the stressors reported by the nurses are summarized. The coping strategies the nurses report using are classified into categories of adaptive and maladaptive responses to stress. In addition, the nursing implications of the coping strategies used by the nurses are also considered.

Adaptation, Psychological↗

Retrospective analysis of healing in wounds cared for by ET nurses versus staff nurses in a home setting.

The continually growing home car market is seeing a higher percentage of patients with wounds. The findings of this investigation may assist the industry in determining whether the higher cost of employing ET nurses is justified. This study compared the outcome of wound care in the home setting provided by ET nurses with outcomes of wound care provided by staff nurses in the same setting. The investigation was a retrospective study of the total population of patients with wounds (n = 519) admitted to five home care agencies in central and south Florida over an 18-month period. The sample consisted of 344 wounds cared for by ET nurses and 464 wounds cared for by staff nurses. The following data were collected through retrospective review of the records: stage of wounds, descriptions of the wounds, types of wounds, number of nursing visits, number of healed wounds, and time to heal each wound. Only 36.3% of the wounds not cared for by ET nurses healed in the time the patients were seen for skilled-nursing services by the home health care agencies. Of the ET-nursed wounds, 78.5% healed. The average number of skilled-nursing visits for patients not nursed by ET nurses was less than 17. ET-nursed patients were seen an average of 31.6 visits.

Aged↗

Parental smoking and carriage of Neisseria meningitidis among Greek schoolchildren.

In December 1990 and January 1991, primary (320) and secondary (697) pupils in 2 areas of Athens were screened to determine the rate of carriage of Neisseria meningitidis and to determine if the genetic and environmental factors associated with carriage of meningococci in Greece were similar to those observed for northern European populations. In 1 area, socioeconomic indicators were significantly lower than in the other (p < 0.0005), but the isolation rates from pupils in the areas were similar, 5.3% and 6.3%. In contrast to studies in northwest Europe, carriage was not associated with lower socioeconomic conditions, sex, numbers of individuals per household, upper respiratory tract infection, or secretor status. By univariate analysis, carriage was associated with age (15-18 years) (p < 0.05) and mother's or other carer's smoking habits (p < 0.05)--but not father's smoking. Although the proportion of fathers who smoked was greater in the area where socioeconomic indicators were lower (61%) vs. (47%) (p < 0.0005), the proportions of women smokers were similar (33% vs. 38%). By multiple regression analysis, the only significant factors were age (p < 0.01) and carer's smoking (p < 0.05).

Carrier State↗

Folate/vitamin B12 inter-relationships.

Folate deficiency causes anaemia owing to impaired purine and pyrimidine biosynthesis. Vitamin B12 deficiency causes an identical anaemia owing to metabolic trapping of intracellular folate. Vitamin B12 also causes nerve damage. Unlike the anaemia, the nerve damage is probably owing to inhibition of methyltransferase involved in nerve cell biosynthesis. This decreased activity is owing to a reduction in the availability of SAM, the methyl donor, together with product inhibition by its demethylated form, SAH.

Animals↗

Reversed-phase high-performance liquid chromatographic method for the quantitation of endogenous folate catabolites in rat urine.

We describe a reversed-phase high-performance liquid chromatographic procedure for the analysis of rat urine for p-aminobenzoylglutamate (pABGlu) and its acetamido derivative (p-acetamidobenzoylglutamate, apABGlu). These two catabolites arise following the in vivo cleavage of the folate molecule at the C-9-N-10 bond. Known quantities of high-specific-activity tritiated forms of the catabolites are added as internal standards to aliquots of rat urine. Following preliminary sample clean-up on C18 Sep-Pak cartridges, including derivatisation in the case of pABGlu, the urinary extracts are quantitated by HPLC. The present assay makes possible for the first time the determination of endogenous folate breakdown in the rat.

4-Aminobenzoic Acid↗

Flow cytometric analysis of surface major histocompatibility complex class II expression on human epithelial cells prepared from small intestinal biopsies.

A technique for preparing viable, single cell suspensions of the epithelial layer of small intestinal tissue obtained endoscopically is described. Constant agitation of four biopsies for 60 min in the presence of chelating and reducing agents gave yields of 1.2-6.7 x 10(6) cells, of which 11-30% were intraepithelial lymphocytes (IEL). Passage through a nylon wool column removed dead cells. This preparation was suitable for flow cytometric analysis. Using this technique, surface MHC class II molecule expression was studied in 14 patients with normal small intestinal mucosa. Fluorescence labelling of these cells showed strong HLA-DR expression by epithelial cells (EC), DP was expressed less strongly, while little DQ expression could be detected. This technique demonstrates that small intestinal biopsies taken during routine endoscopy can yield adequate numbers of viable epithelial cells to perform flow cytometric analysis.

Adolescent↗

The quantitative analysis of endogenous folate catabolites in human urine.

In man folates are catabolized and excreted as inactive cleaved degradation products, a mixture of pteridines and p-aminobenzoylglutamate (pABGlu) or its acetamido derivative (apABGlu). The daily rate of excretion represents the inescapable use of the vitamin in metabolic activity and thus has implications for determining the recommended dietary allowance for the vitamin. Furthermore, the rate of catabolism has been suggested to rise during pregnancy and in certain disease states. A method is described for the quantitative extraction and assay of the folate catabolites pABGlu and apABGlu in human urine. Aliquots of 24-h urine collections are acidified and applied to columns of Dowex 50W cation-exchange resin. The catabolites are selectively batch-eluted with increasing concentrations of HCl. The fraction containing pABGlu is diazotized and then applied to a C18 Sep Pak column for further purification and concentration. The fraction containing apABGlu was deacetylated and reapplied to the Dowex column and then treated identically to the pABGlu fraction. The methanolic concentrates of both extracts were evaporated to dryness and reconstituted with water and pABGlu was regenerated by reductive cleavage of the diazotized material with Zn/HCl. The extracts of the two catabolites were separated by reverse-phase HPLC using a Radial Pak C18 column. Recovery of isolated material was monitored by the addition of high specific activity tritiated labels of both compounds added as internal standards to all urine aliquots prior to purification and analysis.

4-Aminobenzoic Acid↗