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Biomedical subjects

B Ray

Publications and source records attributed to B Ray.

At least 19 recordsLinked to original sources
PubMed2006

A non-randomised controlled trial of the clinical and cost effectiveness of a Supervised Exercise Programme for claudication.

OBJECTIVES: The main aims of treatment in patients with intermittent claudication (IC) are to improve the clinical indicators of lower limb ischaemia and patients' quality of life (QoL). The aims of this study were assess the clinical and cost effectiveness of a supervised exercise programme (SEP) in patients with IC. DESIGN: Non-randomised, controlled trial. SETTING: University teaching hospital. PATIENTS AND METHODS: Two groups of patients with IC were studied. Seventy patients were sequentially recruited before and after the establishment of a Supervised Exercise Programme at our unit. Thirty-seven patients (median age 69 years, 26 men) received conservative medical therapy (CMT) and 33 patients (median age 67 years, 22 men) received CMT plus a 3 month SEP of graduated physical exercise for sixty minutes, three times each week. Patients were assessed prior to and at 6 months following treatment. At each assessment patient reported walking distances (PRWD), treadmill claudication and maximal distances (ICD and MWD), ankle brachial pressure indices (ABPI) pre & post exercise and patient reported QoL using the SF36 questionnaire were assessed. RESULTS: Prior to intervention the two groups were well matched. Following treatment, CMT patients demonstrated no significant change in PRWD or ICD but did record a small but significant improvement in MWD. CMT was also associated with a negative effect size in the SF36 index and in 7 of the 8 SF36 QoL domains, effect size >-0.5 for the domains of Physical Function and Emotional Role. SEP patients demonstrated significant improvement in PRWD, ICD and MWD. SEP was associated with a positive effect size in the SF36 index and in 2 SF36 QoL domains but a negative effect size in a further 2 domains. However, all QoL effect sizes following SEP were < +/-0.5. Intergroup differences in effect sizes were >0.5 for the SF36 domains of Physical Function, Physical Role, Emotion Role and SF36 index. SEP resulted in a 0.027 quality adjusted life year (QALY) gain over CMT in the first year post-treatment thus the cost/QALY gained of SEP is pound1780 at 1 year. CONCLUSIONS: Compared to CMT, SEP increases walking distances, improves QoL and is a highly cost-effective treatment for IC.

Aged↗
PubMed2006

Formation of density waves in traffic flow through intersecting roads.

The formation of density waves in two intersecting roads, with a traffic circle at the intersection, is studied. It is found that, depending on the traffic densities in the two roads, density waves can form in the traffic circle and in one or both of the roads. Depending on the expression chosen for the optimal velocity, either the congestion moves entirely to the traffic circle or the congestion becomes confined to the traffic circle and a part of the road approaching the traffic circle.

Journal Article↗
PubMed2005

Large loop excision and cold coagulation for management of cervical intraepithelial neoplasia.

OBJECTIVES: To evaluate the efficacy of large loop excision of the transformation zone (LLETZ) combined with a single application of the cone probe of a Semm Cold Coagulator as a new treatment for women with cervical intraepithelial neoplasia (CIN). METHODS: Retrospective case-record review of 666 women treated with large loop excision and cold coagulation (LLECC) from 1992 to 2000. RESULTS: Of the women who had high-grade CIN at their initial consultation, 4.2% had abnormal cytologic results 6 months after treatment and 0.6% had abnormal cytologic results at 12 months. Of the women who had low-grade CIN at initial presentation, 3.8% had abnormal cytologic results 6 months after treatment and none (0%) at 12 months. Furthermore, there were no reported cases of cervical cancer in this cohort of women during the follow-up period. Short-term bleeding complications (within 24 h of the procedure) occurred in 1% of the women assessed. CONCLUSIONS: Large loop excision combined with cold coagulation is a new and effective treatment for CIN. Randomized controlled trials are required to confirm these findings and determine the long-term safety of the technique.

Adult↗
PubMed2005

Gene organization and sequences of pediocin AcH/PA-1 production operons in Pediococcus and Lactobacillus plasmids.

AIMS: To determine the locations and sequences of pediocin AcH production genes in Pediococcus parvulus ATO77 from vegetables, Lactobacillus plantarum WHE92 from Muenster cheese, and a lactose-fermenting isolate Pediococcus pentosaceus S34 from buffalo milk. METHODS AND RESULTS: Plasmid curing, Southern blot hybridization, and DNA sequence analysis indicate that pediocin AcH production genes are encoded by highly similar operons in unique plasmids designated pATO77 from P. parvulus ATO77, pS34 from P. pentosaceus S34, and pWHE92 from Lact. plantarum WHE92. Structure, immunity and secretion system genes are linked together in the operons, and the promoter sequences are the same. The amino acid sequences of the encoded proteins are highly conserved between plasmids. CONCLUSIONS: Pediocin AcH production genes are located within a plasmid-borne operon cassette in all lactic acid bacterial strains examined to date. All four genes needed for production are present within a single plasmid in each strain. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first demonstration that the expression of a class IIa bacteriocin is directed by a common gene cassette that has been disseminated to unique plasmids in different genera of lactic acid bacteria. These plasmids should be useful for expressing pediocin AcH in Pediococcus and Lactobacillus strains used in food production.

Bacteriocins↗
PubMed2004

Viability loss and morphology change of foodborne pathogens following exposure to hydrostatic pressures in the presence and absence of bacteriocins.

Cell suspensions of three pathogens were exposed to hydrostatic pressure (HP), bacteriocin mixture (nisin and pediocin) or a combination of HP+bacteriocins and changes in colony forming units (cfu) and cell-morphology by scanning electron microscopy (SEM) were studied. Cell viability loss, as determined from the reduction in cfu before and after a treatment, occurred in Listeria monocytogenes by all three treatments and in Salmonella typhimurium and Escherichia coli O157:H7 by HP and HP+bacteriocin combination. Cell wall and cell membrane collapse and cell lysis was indicated in L. monocytogenes exposed to bacteriocin or HP+bacteriocin and in Salmonella and E. coli exposed to HP or HP+bacteriocin.

Anti-Bacterial Agents↗
PubMed2004

A comparative study of aortic wall stress using finite element analysis for ruptured and non-ruptured abdominal aortic aneurysms.

BACKGROUND: The decision to repair an asymptomatic abdominal aortic aneurysm (AAA) is currently based on diameter (> or =5.5 cm) alone. However, aneurysms less than 5.5 cm do rupture while some reach greater than 5.5 cm without rupturing. Hence the need to predict the risk of rupture on an individual patient basis is important. This study aims to calculate and compare wall stress in ruptured and non-ruptured AAA. METHODS: The 3D geometries of AAA were derived from CT scans of 27 patients (12 ruptured and 15 non-ruptured). AAA geometry, systolic blood pressure and literature derived material properties, were utilised to calculate wall stress for individual AAA using finite element analysis. RESULTS: Peak wall stress was significantly higher in the ruptured AAA (mean 1.02 MPa) than the non-ruptured AAA (mean 0.62 MPa). In patients with an identifiable site of rupture on CT scan, the area of peak wall stress correlated with rupture site. CONCLUSIONS: Peak wall stress can be calculated from routinely performed CT scans and may be a better predictor of risk of rupture than AAA diameter on an individual patient basis.

Aged↗
PubMed2003

Sex-steroid derived compounds induce sex-specific effects on autonomic nervous system function in humans.

The physiological and psychological effects of 2 human sex-steroid derived compounds, 4.16-androstadien-3-one (AND) and l,3,5(10),16-estratetraen-3-ol(EST) were measured in 24 subjects who participated in a within-subjects, double-blind experiment. A dissociation was evident in the physiological effects of AND, in that it increased physiological arousal in women but decreased it in men. EST did not significantly affect physiological arousal in women or men. Neither compound significantly affected mood. AND is an androgen derivative that is the most prevalent androstene in human male sweat, male axillary hair, and on the male axillary skin surface. The authors argue that AND's opposite effects on physiology in men and women further implicate this compound in chemical communication between humans.

Adult↗
PubMed2003

Effect of polymer tacticity on the molecular structure of polyelectrolyte/surfactant stoichiometric complexes in solutions and gels.

The molecular structure of polystyrene sulphonate/CTAB stoichiometric complexes has been examined by means of small-angle neutron scattering in solutions and in the gel state for two different tacticities of the polystyrene moiety, namely atactic polystyrene and isotactic polystyrene. It is found that tacticity has no influence on the molecular structure in solution, while it plays a role in the gel state. The neutron scattering curves are interpreted with different helical models. The thermal properties of the gels are discussed in the light of the neutron scattering outcomes.

1-Butanol↗
PubMed2003

Carcinoma in the gastric pouch years after vertical banded gastroplasty.

A 67-year-old lady presented with anemia and weight loss 15 years after vertical banded gastroplasty. The cancer was confined to the pouch, which is suggestive of a relationship to the anti-obesity surgery. A brief review with possible contributing factors is presented.

Adenocarcinoma, Mucinous↗
PubMed2001

Conformational changes in pediocin AcH upon vesicle binding and approximation of the membrane-bound structure in detergent micelles.

Pediocin AcH is a 44-residue antimicrobial peptide with bactericidal potency against Gram-positive bacteria such as Listeria. It belongs to a family of bacteriocins that, when membrane-associated, is predicted to contain beta-sheet and alpha-helical regions. All bacteriocins in this family have a conserved N-terminal disulfide bond. An additional C-terminal disulfide bond in pediocin AcH is thought to confer enhanced potency and broader specificity range against sensitive bacteria. The C-terminal disulfide bond may also affect the conformation of the C-terminus. The secondary structures of pediocin AcH in aqueous solution and vesicles from susceptible cells, as well as the ability of trifluoroethanol (TFE) and detergent systems to induce secondary structures like those induced in vesicles, were studied by circular dichroism (CD) spectroscopy. Like related peptides, pediocin AcH was highly unordered in aqueous solution, 56%. However, it also contained 20% beta-strand and 15% beta-turn structures. Upon complete binding to vesicles, 32% alpha-helical structure formed, the unordered structure decreased to 32%, and the beta-strand and beta-turn structures remained largely unchanged. Thus, a betaalpha domain structure formed in vesicles. The helical structure likely forces the C-terminal tail to loop back on the helix so that the C24-C44 disulfide bond can form. Detergent micelles were superior to TFE in their ability to induce secondary structural fractions in pediocin AcH comparable to those observed in vesicles. This demonstrates the importance of a hydrocarbon-water interface to pediocin AcH structure induction and suggests that it is preferable to use detergent micelles as solvents in NMR studies of pediocin AcH structure.

Amino Acid Sequence↗
PubMed2001

Structural features of a water soluble gum polysaccharide from Murraya paniculata fruits.

A water soluble gum polysaccharide was isolated from Murraya paniculata fruits. Hydrolytic experiments, methylation analysis, periodate oxidation studies and NMR data revealed that the polysaccharide was extensively branched and it consisted of 1,3-, and 1,3,6-linked beta-D-galactopyranosyl units, terminal beta-D-galactopyranosyl units and terminal alpha-D-glucopyranosyl 1,4-beta-D-galactopyranosyl units. Small amounts of 4-O-methylglucuronic acid residues were also present.

Anions↗
PubMed2001

Molecular typing of HLA-A, -B, and DRB using a high throughput micro array format.

The goal of this study was to develop a DNA micro array procedure for molecular human leukocyte antigen (HLA) typing of a large number of samples. DNA was isolated from peripheral blood samples and polymerase chain reaction (PCR) amplified for HLA-A, -B, and -DRB. Amplified DNA samples were spotted on silane-treated glass slides using a micro array spotter. The spotter was capable of spotting multiple slides with up to 9216 samples per slide or 2304 samples in quadruplicate. The allele specific oligo nucleotide probes for HLA-A, -B, and -DRB were labeled with the fluorescent dye Cy3, while a control probe, to quantitate the total amount of PCR product in a sample, was labeled with Cy5. Each slide was hybridized with a mixture of an allele specific Cy3 probe plus the control Cy5 probe. Following hybridization and wash, the amount of probe hybridizing to each DNA sample on the slide was measured with a micro array scanner. A computer program was used for image analysis, to calculate the average Cy3/Cy5 ratios and to identify the positive and negative samples. In turn, this information was used to determine the HLA phenotype of each sample. There was very good concordance between the results obtained for all three loci using Cy-labeled probes as compared with those previously obtained by chemiluminescent detection of alkaline phosphatase labeled probes. This methodology has the potential of greatly simplifying HLA molecular typing of large number of samples.

Alleles↗
PubMed2001

Isolation, purification and some structural features of the mucilaginous exudate from Musa paradisiaca.

The water-soluble polysaccharides isolated from the vascular gel of Musa paradisiaca, were fractionated via anion exchange chromatography into four fractions. Fractionated polymers contained arabinose, xylose and galacturonic acid as major sugars, together with traces of galactose, rhamnose, mannose and glucose residues. Methylation analysis revealed the presence of a highly branched arabinoxylan with a significant amount of terminal arabinopyranosyl units and an arabinogalactan type I pectin. Periodate oxidation studies supported the results of methylation analysis.

Humans↗
PubMed2001

Role of the medial preoptic area in thermal preference of rats.

This study was conducted to find out whether the medial preoptic area (mPOA) plays a role in the selection of ambient temperature by rats. Adult male Wistar rats were kept in an environmental chamber having three interconnected compartments, maintained at three different temperatures (18 degrees, 24 degrees and 30 degrees C) in which the animals could move freely from one compartment to the other. Normal rats preferred to stay at the chamber maintained at 24 degrees C for most of the time, during day and night. The temperature preference shifted to 30 degrees C after the mPOA of these rats had been lesioned by local administration of 5 micrograms of N-methyl D-aspartic acid (NMDA) in 0.2 microliter distilled water. The results of the study suggest that the mPOA acts as a fine tuning center for homeostatic regulation of thermal balance, including selection of appropriate thermal environment. It is proposed that after the mPOA lesion, the animal cannot assess properly the energy status of the body and thereby prefers a higher ambient temperature.

Animals↗
PubMed2000

Emergence of a new Vibrio parahaemolyticus serotype in raw oysters: A prevention quandary.

CONTEXT: In May and June 1998, reported Vibrio parahaemolyticus infections increased sharply in Texas. OBJECTIVE: To determine factors that contributed to the increase in V parahaemolyticus infections. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional survey of persons reporting gastroenteritis after eating seafood in Texas; survey of environmental conditions in Galveston Bay. MAIN OUTCOME MEASURES: Traceback of oysters, water quality measures in harvest areas, presence of V parahaemolyticus in stool cultures; comparison of median values for environmental conditions before and during the outbreak compared with during the previous 5 years. RESULTS: Between May 31 and July 10, 1998, 416 persons in 13 states reported having gastroenteritis after eating oysters harvested from Galveston Bay. All 28 available stool specimens from affected persons yielded V parahaemolyticus serotype O3:K6 isolates. Oyster beds met current bacteriologic standards during harvest and fecal coliform counts in water samples were within acceptable limits. Median water temperature and salinity during May and June 1998 were 30.0 degrees C and 29.6 parts per thousand (ppt) compared with 28.9 degrees C and 15.6 ppt for the previous 5 years (P<.001). CONCLUSIONS: This is the first reported outbreak of V parahaemolyticus serotype O3:K6 infection in the United States. The emergence of a virulent serotype and elevated seawater temperatures and salinity levels may have contributed to this large multistate outbreak of V parahaemolyticus. Bacteriologic monitoring at harvest sites did not prevent this outbreak, suggesting that current policy and regulations regarding the safety of raw oysters require reevaluation. Consumers and physicians should understand that raw or undercooked oysters can cause illness even if harvested from monitored beds. In patients who develop acute gastroenteritis within 4 days of consuming raw or undercooked oysters, a stool specimen should be tested for Vibrio species using specific media. JAMA. 2000;284:1541-1545.

Animals↗