PubMed Health⌕ Search

Biomedical subjects

M Ward

Publications and source records attributed to M Ward.

At least 73 records · Page 4Linked to original sources
PubMed2001

Effects of stenting on adjacent vascular distensibility and neointima formation: role of nitric oxide.

Intravascular stents increase long-term patency but their effects on the vascular mechanics of adjacent segments have not been studied. In this study, stents were deployed in the rabbit abdominal aorta after 1 week of normal diet, 1% cholesterol diet or 1% cholesterol diet with L-nitro arginine (L-NA 60 mg/l water). Intravascular ultrasound showed a small distal decrease in vessel distensibility (area/pressure * 100) before stenting. Distensibility was almost abolished by stenting (0.12 +/- 0.01, p < 0.001), but was increased proximal to the stent and decreased distal to the stent both acutely (proximal: 1.18 +/- 0.10 vs distal: 0.65 +/- 0.06, p < 0.001), and at 4 weeks (proximal: 1.05 +/- 0.08 vs distal: 0.37 +/- 0.07, p < 0.001). Nitric oxide (NO) activity was enhanced proximal to and within the stent, and remained constant distal to the stent, (versus control, proximal: 57 +/- 23%, stent: 136 +/- 35%, distal: 2 +/- 12%, p < 0.01). The I/M ratio was significantly higher proximal to and within the stent than in the distal segment (proximal: 0.40 +/- 0.10, stent: 0.37 +/- 0.12, distal: 0.12 +/- 0.11, p < 0.01). NO blockade with L-NA prevented hyperdistensibility proximally, and significantly increased the I/M ratio within the stent and distally (stent: 0.81 +/- 0.19, distal: 0.30 +/- 0.10, p < 0.05) but not proximally (0.38 +/- 0.09). In conclusion, aortic stenting increases proximal vascular distensibility and intimal lesion formation. Nitric oxide blockade augments intimal growth within but not proximal to the stent.

Animals↗
PubMed2001

Carers' and Users' Expectations of Services--User version (CUES-U): a new instrument to measure the experience of users of mental health services.

BACKGROUND: No existing instrument measures all or even most of the issues considered important by users of mental health services. AIMS: To develop and test a self-assessment instrument to enable users of mental health services to rate their experience across the range of domains that they consider to be important. METHOD: Relevant domains were identified and a new instrument was drafted and field tested to examine its psychometric properties. RESULTS: The 17-item, self-rated Carers' and Users' Expectations of Services--User version (CUES-U) appears acceptable to most service users. Its items have reasonable test-retest reliability and a 'total CUES-U score' correlates significantly with a total score of the Health of the Nations Outcome Scales (Spearman's rho=0.42; P < 0.01). CONCLUSIONS: The development and testing of CUES-U suggest that it might be feasible to apply a self-rated measure of the expectations and experience of users of mental health services.

Adolescent↗
PubMed2001

The role of nutritional therapy in the treatment of equine Cushing's syndrome and laminitis.

Equine Cushing's syndrome, a relatively common and complex condition, is difficult to treat with conventional medicine. Cushing's syndrome involves a hyperplasia or adenoma of the anterior pituitary gland. Biochemical alterations include increased endogenous cortisol, insulin resistance, elevated adrenocorticotrophic hormone, and decreased thyroid hormone levels. Symptoms include hirsutism with no loss of the winter coat in summer, refractory laminitis, weight problems (over- or underweight), polyuria/polydipsia (Pu/Pd), frequent infections, lowered immunity to intestinal parasites, decreased intestinal wall integrity, and infertility. Laminitis (an inflammation of the laminae of the foot) is a common and often fatal complication of Cushing's syndrome that tends to be refractory to conventional treatment. One of the most common therapies is phenylbutazone, a non-steroidal anti-inflammatory drug (NSAID) known to cause significant changes in the permeability of the intestinal wall. Recent research has shown an intestinal bacterial exotoxin to be one of the triggering factors in laminitis. By removing phenylbutazone and healing the intestinal wall, laminitis becomes more responsive to treatment. Good hoof-care combined with nutritional management and the application of other modalities, including acupuncture and Chinese and Western herbs, can complete the healing process. The successful treatment of equine Cushing's syndrome is one of the best examples of treating a disease using the holistic approach. While each case requires different combinations of modalities, the outcome is usually positive with individually selected treatments.

Animal Nutritional Physiological Phenomena↗
PubMed2000

Geographic information systems. A new tool in environmental epidemiology.

PURPOSE: Geographic Information Systems (GIS) are useful tools for identifying populations with potential exposure to environmental contaminants. Using a GIS, features of the local environment around an individual's home, work, or school can be described. We present two examples illustrating methods and issues in identifying populations potentially exposed to agricultural pesticides and to toxic releases from the Toxic Release Inventory (TRI).METHODS: We used USDA Farm Service Agency records as ground reference data to classify a late summer 1984 satellite image into crop species in 3 counties in Nebraska. We located residences from a case-control study of non-Hodgkin's lymphoma (NHL) on the crop maps and calculated the distance to crop fields. Residences from a 4-center study of NHL were mapped and the distance to TRI sites was determined.RESULTS: Twenty-two percent of residences had crop fields within 500 meters of the home, an intermediate distance for the range of drift effects from pesticide applications. After accounting for the extent of primary drift from ground applications of pesticides, we estimated that 30 percent of residences were potentially exposed to crop pesticides. In the 4-center study, residence locations determined by address-matching methods and by a global positioning system were compared; the population 1 mile from specific TRI sites is described.CONCLUSIONS: These examples demonstrate the utility of a GIS in environmental epidemiology studies. A GIS can be a useful addition to questionnaire and other methods of exposure assessment in health studies.

Journal Article↗
PubMed2000

Chlamydia pneumoniae IgG titres and coronary heart disease: prospective study and meta-analysis.

OBJECTIVE: To examine the association between coronary heart disease and serum markers of chronic Chlamydia pneumoniae infection. DESIGN: "Nested" case-control analysis in a prospective cohort study and an updated meta-analysis of previous relevant studies. SETTING: General practices in 18 towns in Britain. PARTICIPANTS: Of the 5661 men aged 40-59 who provided blood samples during 1978-80, 496 men who died from coronary heart disease or had non-fatal myocardial infarction and 989 men who had not developed coronary heart disease by 1996 were included. MAIN OUTCOME MEASURES: IgG serum antibodies to C pneumoniae in baseline samples; details of fatal and non-fatal coronary heart disease from medical records and death certificates. RESULTS: 200 (40%) of the 496 men with coronary heart disease were in the top third of C pneumoniae titres compared with 329 (33%) of the 989 controls. The corresponding odds ratio for coronary heart disease was 1.66 (95% confidence interval 1.25 to 2.21), which fell to 1.22 (0.82 to 1.82) after adjustment for smoking and indicators of socioeconomic status. No strong associations were observed between C pneumoniae IgG titres and blood lipid concentrations, blood pressure, or plasma homocysteine concentration. In aggregate, the present study and 14 other prospective studies of C pneumoniae IgG titres included 3169 cases, yielding a combined odds ratio of 1. 15 (0.97 to 1.36), with no significant heterogeneity among the separate studies (chi(2)=10.5, df=14; P>0.1). CONCLUSION: This study, together with a meta-analysis of previous prospective studies, reliably excludes the existence of any strong association between C pneumoniae IgG titres and incident coronary heart disease. Further studies are required, however, to confirm or refute any modest association that may exist, particularly at younger ages.

Adult↗
PubMed2000

dbSNP: a database of single nucleotide polymorphisms.

In response to a need for a general catalog of genome variation to address the large-scale sampling designs required by association studies, gene mapping and evolutionary biology, the National Cancer for Biotechnology Information (NCBI) has established the dbSNP database. Submissions to dbSNP will be integrated with other sources of information at NCBI such as GenBank, PubMed, LocusLink and the Human Genome Project data. The complete contents of dbSNP are available to the public at website: http://www.ncbi.nlm.nih.gov/SNP. Submitted SNPs can also be downloaded via anonymous FTP at ftp://ncbi.nlm.nih.gov/snp/

Base Sequence↗
PubMed2000

Use of molecular variation in the NCBI dbSNP database.

While high quality information regarding variation in genes is currently available in locus-specific or specialized mutation databases, the need remains for a general catalog of genome variation to address the large-scale sampling designs required by association studies, gene mapping, and evolutionary biology. In response to this need, the National Center for Biotechnology Information (NCBI) has established the dbSNP database http://ncbi. nlm.nih.gov/SNP/ to serve as a generalized, central variation database. Submissions to dbSNP will be integrated with other sources of information at NCBI such as GenBank, PubMed, LocusLink, and the Human Genome Project data, and the complete contents of dbSNP are available to the public via anonymous FTP. Hum Mutat 15:68-75, 2000. Published 2000 Wiley-Liss, Inc.

Databases, Factual↗
PubMed2000

Cross-species identification of novel Candida albicans immunogenic proteins by combination of two-dimensional polyacrylamide gel electrophoresis and mass spectrometry.

We have previously reported the usefulness of two-dimensional gel electrophoresis followed by Western blotting with sera from patients with systemic candidiasis in the detection of the major Candida albicans antigens (Pitarch et al., Electrophoresis 1999, 20, 1001-1010). The identification of these antigens would be useful for the characterization of good markers for the disease, and for the development of efficient diagnostic strategies. In this work we have used nanoelectrospray tandem mass spectrometry to obtain amino acid sequence information from the immunogenic proteins previously detected. We report here the cross-species identification of these antigens by matching of tandem mass spectrometry data to Saccharomyces cerevisiae proteins. Using this approach, we unambiguously identified the four C. albicans immunogenic proteins analyzed, namely aconitase, pyruvate kinase, phosphoglycerate mutase and methionine synthase. Furthermore, we report for the first time that aconitase, methionine synthase and phosphoglycerate mutase have antigenic properties in C. albicans.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed2000

A proteomic approach for the study of Saccharomyces cerevisiae cell wall biogenesis.

In fungi, cell shape is determined by the presence of a rigid cell wall which separates the cell from the extracellular medium. This highly dynamic structure is essential for the maintenance of cell integrity and is involved in several phenomena such as flocculation, adherence and pathogenicity. The composition of the fungal cell wall is well known, but issues such as the assembly and remodeling of its components remain poorly understood. In an attempt to study the de novo construction of the yeast cell wall, we have undertaken a large-scale proteomic approach to analyze the proteins secreted by regenerating protoplasts. Upon incubation of protoplasts in regenerating conditions, numerous proteins are secreted into the culture medium. These presumably include proteins destined for the cell wall, comprising both structural proteins as well as enzymes involved in cell wall biogenesis. This work reports the establishment of a reference map of proteins secreted by regenerating protoplasts by means of two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and their identification by mass spectrometry. Thirty-two different proteins have been identified, including known cell wall proteins, glycolytic enzymes, heat shock proteins, and proteins involved in several other processes. Using this approach, novel proteins possibly involved in cell wall construction have also been identified. This reference map will allow comparative analyses to be carried out on a selected collection of mutants affected in the cell wall.

Amino Acid Sequence↗
PubMed2000

Molecular characterization of a PDI-related gene prpA in Aspergillus niger var. awamori.

A gene (prpA) homologous to the protein disulfide isomerase gene was isolated from Aspergillus niger by Southern hybridization using the pdi1 gene isolated from Trichoderma reesei as a DNA probe. The corresponding cDNA of the prpA gene has also been isolated from an A. niger var. awamori cDNA library. The prpA gene does not belong to any currently recognized family of protein disulfide isomerases since it contains only a single conserved thioredoxin domain at the N-terminus of the protein. The C-terminal two-thirds of the protein has no homology to any known proteins in the database. The PRPA protein contains an ER retention signal (HDEL) at its C-terminal end suggesting that it is located in the ER. Southern hybridization at high stringency showed that it was present as a single copy in the genome. Northern hybridization indicated that the transcript level of the prpA gene was higher if the cells were secreting a heterologous protein, bovine prochymosin. However, over-expression of the prpA gene from a multicopy integrated vector had little effect on chymosin secretion. A strain containing a deletion of the prpA gene was viable. However, deletion of the prpA gene appeared to cause a reduction of bovine chymosin production.

Amino Acid Sequence↗
PubMed2000

Unusual cause of chest pain in a 60-year-old woman.

Chest pain is a common emergency department complaint. Many patients presenting with this complaint are discharged with the nonspecific diagnosis of musculoskeletal chest pain. That was the diagnosis given to the patient in this case at the time of her initial presentation to the ED, a diagnosis that was correct but incomplete. This case illustrates the importance of taking a complete history, including a thorough review of systems in every patient, even when the diagnosis seems obvious.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Experimental study of the effects of Optison concentration on sonoporation in vitro.

Lethal sonoporation and reparable sonoporation were observed in Jurkat lymphocytes in suspension with the addition of varying amounts of Optison, a commercially available bubble-based contrast agent. For given ultrasound (US) exposure conditions (spatial peak-pressure amplitude of 0.2 MPa, duty cycle 10% and 2-MHz frequency), sonoporation was directly related to the bubble-to-cell ratio (in a range from 0 to 230). It was found that the nearest bubble-cell spacing was also related to the occurrence frequency of bioeffects. A constant bubble-to-cell ratio often provided very different results for two different initial cell concentrations (200,000 cells/mL and 600,000 cells/mL), with the higher cell concentration generally exhibiting higher levels of sonoporation. In contrast, a constant bubble-to-cell spacing provided similar results between the two initial cell concentrations. The frequency of reparable and lethal sonoporation was seen to decay as the inverse-cube power of the nearest bubble-cell spacing. Significant reparable sonoporation was observed at a bubble-cell spacing that was 10 microm larger than the minimum spacing at which significant lethal sonoporation was observed. Preliminary analysis also suggests the possibility of a step-wise increase in lethal sonoporation as spacing decreases; further experiment is needed.

Albumins↗
PubMed2000

Efficient retrovirus-mediated transfer of the multidrug resistance 1 gene into autologous human long-term repopulating hematopoietic stem cells.

Pre-clinical studies indicate that efficient retrovirus-mediated gene transfer into hematopoietic stem cells and progenitor cells can be achieved by co-localizing retroviral particles and target cells on specific adhesion domains of fibronectin. In this pilot study, we used this technique to transfer the human multidrug resistance 1 gene into stem and progenitor cells of patients with germ cell tumors undergoing autologous transplantation. There was efficient gene transfer into stem and progenitor cells in the presence of recombinant fibronectin fragment CH-296. The infusion of these cells was associated with no harmful effects and led to prompt hematopoietic recovery. There was in vivo vector expression, but it may have been limited by the high rate of aberrant splicing of the multidrug resistance 1 gene in the vector. Gene marking has persisted more than a year at levels higher than previously reported in humans.

Adolescent↗
PubMed2000

The gills are an important site of iNOS expression in rainbow trout Oncorhynchus mykiss after challenge with the gram-positive pathogen Renibacterium salmoninarum.

Following injection challenge of rainbow trout with the Gram-positive pathogen Renibacterium salmoninarum, serum nitrate levels increased indicative of NO production. The timing and amount of nitrate produced varied with the virulence of the bacterial strain used, with the highest levels seen in fish challenged with the most virulent (autoaggregating) strain. Immunization with a killed R. salmoninarum preparation in Freund's incomplete adjuvant significantly increased nitrate levels after challenge. Inducible nitric oxide synthase (iNOS) transcript expression was detectable in rainbow trout tissues after injection challenge with R. salmoninarum, and its induction in the gills was both quick (between 3 and 6 hr) and relatively prolonged (lasting several days). iNOS expression in the kidney was also seen at a later stage (24 hr) but appeared to switch off relatively rapidly. Bath challenge with R. salmoninarum also induced iNOS expression in gill, and a variable expression in the gut and kidney also occurred. These results highlight the importance of the gills, not only as a point of entry of pathogens but also as a tissue capable of mounting an immune response.

Animals↗
PubMed2000

Response of red blood cell folate to intervention: implications for folate recommendations for the prevention of neural tube defects.

Committees worldwide have set almost identical folate recommendations for the prevention of the first occurrence of neural tube defects (NTDs). We evaluate these recommendations by reviewing the results of intervention studies that examined the response of red blood cell folate to altered folate intake. Three options are suggested to achieve the extra 400 microg folic acid/d being recommended by the official committees: increased intake of folate-rich foods, dietary folic acid supplementation, and folic acid fortification of food. A significant increase in foods naturally rich in folates was shown to be a relatively ineffective means of increasing red blood cell folate status in women compared with equivalent intakes of folic acid-fortified food, presumably because the synthetic form of the vitamin is more stable and more bioavailable. Although folic acid supplements are highly effective in optimizing folate status, supplementation is not an effective strategy for the primary prevention of NTDs because of poor compliance. Thus, food fortification is seen by many as the only option likely to succeed. Mandatory folic acid fortification of grain products was introduced recently in the United States at a level projected to provide an additional mean intake of 100 microg folic acid/d, but some feel that this policy does not go far enough. A recent clinical trial predicted that the additional intake of folic acid in the United States will reduce NTDs by >20%, whereas 200 microg/d would be highly protective and is the dose also shown to be optimal in lowering plasma homocysteine, with possible benefits in preventing cardiovascular disease. Thus, an amount lower than the current target of an extra 400 microg/d may be sufficient to increase red blood cell folate to concentrations associated with the lowest risk of NTDs, but further investigation is warranted to establish the optimal amount.

Erythrocytes↗
PubMed2000

Fluctuations in dietary methionine intake do not alter plasma homocysteine concentration in healthy men.

A moderate elevation in plasma total homocysteine (tHcy) has been established as an independent risk factor for vascular disease. An important exogenous source of homocysteine is methionine found in foods rich in animal protein. We investigated the response of tHcy to fluctuations in methionine intake in a cross-over intervention trial (two arms). Healthy men (n = 52; 19-29 y) were screened for habitual methionine intake using a food-frequency questionnaire. Subjects in the top quartile for methionine intake (n = 13), with a baseline fasting tHcy of 7.01 +/- 1.84 micromol/L (mean +/- SD), were randomly assigned to receive either a low-methionine intervention diet for 1 wk followed by a control diet for 1 wk or vice-versa. Simultaneously, those in the bottom quartile for methionine intake (n = 11), with a fasting plasma tHcy of 9.79 +/- 7. 20 micromol/L (mean +/- SD), received either a high methionine intervention diet for 1 wk followed by a control diet or vice-versa. All subjects had serum folate, red-cell folate, serum vitamin B-12 and plasma pyridoxal phosphate (PLP) concentrations within normal ranges. During the intervention, subjects in the top quartile for methionine intake reduced their daily methionine intake 79%, from 1969 +/- 639 to 407 +/- 83 mg/d (P: </= 0.001), and those in the bottom quartile almost doubled their methionine intake, from 1155 +/- 401 to 2112 +/- 379 mg/d (P: </= 0.001). Despite these changes in methionine intake, no corresponding changes in plasma tHcy were observed. These results suggest that in the absence of an obvious deficiency of relevant B-vitamins, fasting plasma tHcy is unaffected by intermediate-term fluctuations (up to 100% of usual intake) in dietary methionine.

Adult↗