Biomedical subjects

G Reid

Publications and source records attributed to G Reid.

At least 55 records · Page 3Linked to original sources

PubMed2000

Rapid assessment of drug use and HIV vulnerability in south-east and east Asia.

In an 8-week period in late 1997, an assessment of the situation of drug use and HIV vulnerability in east and south-east Asia was carried out for the United Nations Joint Programme on AIDS (UNAIDS). It served to assist UNAIDS' Asia-Pacific team in setting priorities for action at a regional level, it having been realised that epidemics of HIV among injecting drug users (IDUs) were playing an important role in the development of the AIDS epidemic in Asia at both country and regional levels. Though essentially a desk exercise, contact with the extensive membership of the Asian Harm Reduction Network allowed a deeper and more efficient investigation than would otherwise have been possible, with access to key informants and 'grey' literature. The assessment found a situation of massive epidemics of HIV among IDUs either occurring, or about to occur, in most Asian countries; and parlous or non-existent public health responses to these problems in a context void of policy. As well as providing evidence to guide UNAIDS, and useful for advocacy by a wide range of people, the process of the situation assessment also generated interest and in some cases activity on the part of many individuals and institutions throughout the region. It is hoped that this will be the beginning of an ongoing monitoring of the situation.

Journal Article↗

PubMed2000

Advances in ureteral stent technology.

This review focuses on technological advances and relevant research related to ureteral stents. The importance of physical and chemical biomaterial type, biocompatibility, material coatings such as hydrogels, and infection related to indwelling ureteral stents are discussed. Recent in vitro and in vivo research has focused on materials that will reduce encrustation and bacterial biofilm formation. The adsorption of antimicrobials onto devices holds promise of reducing infection rates, but multidrug resistant bacteria, short leaching times and adverse side effects make it essential that alternative strategies be investigated. Just so, encrustation limits the long-term use of urinary materials, and a better understanding of factors involved in encrustation are needed to reduce the problem.

Biocompatible Materials↗

PubMed2000

Inhibition of uropathogenic biofilm growth on silicone rubber in human urine by lactobacilli--a teleologic approach.

The ability of three Lactobacillus strains to inhibit the adhesion and growth of naturally occurring uropathogens on silicone rubber was investigated in human urine. The importance of biosurfactant production by Lactobacillus in discouraging uropathogen growth was determined in relation to the binding affinities of the lactobacilli for silicone rubber. L. fermentum B54 markedly inhibited uropathogen growth on the silicone rubber disks after 8 days for all five men included in the study, albeit to various extents ranging from 77% to 100%. In urine from women, however, this inhibition was less clear, as it was absent for two of the four women participating in this study. L. casei rhamnosus 36 completely discouraged uropathogen growth on the disks after 8 days for three of the four women, whereas its effect in urine from men was less pronounced (inhibition ranged from 48% to 100% and was absent for one man). L. casei rhamnosus ATCC 7469T was the least inhibitory Lactobacillus strain tested and inhibition was absent for a number of both male and female participants, possibly as a result of the low binding affinity of this strain for silicone rubber and of its inability to release biosurfactants. We conclude that the inhibition of uropathogen growth is dependent on the Lactobacillus strain involved, and for L. fermentum B54 it was demonstrated to be sex-related. Hence, inhibition must be considered a multifactorial process.

Adult↗

PubMed2000

Probiotic Therapy and Functional Foods for Prevention of Urinary Tract Infections: State of the Art and Science.

In the past year, interest has heightened in the potential for probiotics to prevent urinary tract infection (UTI). Mainly, this has been due to concerns about antibiotic resistance and recognition of the scientific efficacy of probiotics. The critical factors in any successful application of probiotics to patient care are the scientific basis for selecting probiotic strains and clinical verification that they are effective against the recurrence of UTI. Three strains--Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum B-54 and RC-14--have been shown to colonize the vagina and act as a barrier to the ascension of uropathogens into the bladder. Their ability to produce growth and adhesion antagonists against urogenital pathogens is clinically important, because these appear to be important mechanisms of action. Probiotic therapy has been shown to be safe, but too few reliable products are on the market, and none are yet available for use against UTI. Given the right strains and delivery system, probiotic therapy could provide the first new UTI-prevention system in 40 years, and may help in the management of recurrent UTI.

Journal Article↗

PubMed2000

Probiotics in the Treatment of Diarrheal Diseases.

Infections of the gastrointestinal tract are a major health problem worldwide, and many result in death, especially in the Third World. The approach to treatment and prevention of these infections has revolved around antibiotic administration for many years, but the emergence of multidrug-resistant pathogens is forcing people to look at alternatives to antibiotics. For more than 100 years, probiotic remedies (viable organisms that benefit the host by improving the microbial balance) have been used to fight infection. Now, substantial scientific and clinical evidence indicates that certain well-selected probiotic organisms can reduce the risk and duration of diarrhea.

Journal Article↗

PubMed2000

Design and validation of immunological tests for the detection of Porcine endogenous retrovirus in biological materials.

The present study details the design and demonstrates function for a series of reagents and methods to allow the detection of exposure to antigens specific for Porcine endogenous retrovirus (PERV). The detection of PERV is carried out by the means of a variety of immunological screening methods including, indirect immunofluorescence, Western blotting and enzyme linked immunosorbent assay (ELISA) for the detection of antibodies in serum specific for PERV gag and env antigens. Alternatively, PERV-specific antisera for gag and env can be used to detect viral antigen in serum or other samples. PERV env peptides with potential specificity for the known PERV types are also described. Antisera against the peptides can be used to detect PERV antigens directly or to characterise viral type. Using electron microscopy coupled with labelled PERV-gag-specific antisera it was possible to visualise PERV virions.

Amino Acid Sequence↗

PubMed2000

Ofloxacin for the treatment of urinary tract infections and biofilms in spinal cord injury.

Forty two paraplegic and quadriplegic hospitalized spinal cord injured patients with urinary tract infections (UTI) were included in a double blind, randomized treatment study comparing 7 days ofloxacin (300 mg bd) with trimethoprim-sulphamethoxazole (TMPSMX; 160-800 mg bd) or an alternative, chosen because of resistance to TMPSMX. The 4-day clinical cure rate, defined as an asymptomatic patient with sterile urine, was 90% (19/21) with ofloxacin, significantly greater than 48% (10/21) for the comparison group (P=0.003) and the rate at end of therapy was 90% (19/21) with ofloxacin, against 57% (12/21) (P=0.015). Bacterial biofilms were detected on bladder epithelial cells in 39/41 (95%) patients. The biofilm score fell significantly following ofloxacin therapy (P < 0.001) or alternative therapy (P < 0.001). Ofloxacin treatment led to significantly more biofilm eradication than the other antibiotic group on day 4 (62 vs. 24%) (P=0.005) and day 7 (67 vs. 35%) (P=0.014). The study showed that ofloxacin was better than TMPSMX and alternatives at relieving clinical infection and eradicating bladder cell biofilms.

Administration, Oral↗

PubMed2000

Laparoscopic excision of endocervicosis of the urinary bladder.

Endocervicosis is a benign lesion in which endocervical mucosa develops in anatomic locations distant from the endocervical canal. Two cases of infiltrating endocervicosis of the urinary bladder were managed by laparoscopic partial cystectomy. This avoided the morbidity of laparotomy and provided improved visualization of the extent of bladder resection required to remove the lesion completely.

Adult↗

PubMed2000

Activity of cecropin P1 and FA-LL-37 against urogenital microflora.

Two mammalian antimicrobial peptides, FA-LL-37 and cecropin P1, were tested for activity against six uropathogens and five Lactobacillus strains by broth microdilution assay. Both peptides inhibited Escherichia coli at 25 microM (FA-LL-39), and 1.56 microM (cecropin P1), Pseudomonas aeruginosa (12.5 microM, and 25 microM), and Klebsiella pneumoniae, (50 microM, and 1.56 microM), but not Enterococcus faecalis and Staphylococcus epidermidis. FA-LL-37 acted bacteriocidally against E. coli and bacteriostatically against the other two Gram-negative organisms. Cecropin P1 was bacteriocidal to all susceptible bacteria. Lactobacilli were resistant to both peptides, with the exception of poultry isolate Lactobacillus fermentum B-54, which was susceptible to FA-LL-37 at 100 microM. The differential activities of these peptides toward Gram-negative uropathogens versus urogenital lactobacilli demonstrate their potential as a topical treatment for urinary tract infections. In addition, production of such peptides in vivo could be a natural mechanism to aid in the maintenance of the lactobacilli-dominated urogenital flora at the expense of pathogens.

Amino Acid Sequence↗

PubMed2000

Ethanol with a mixed meal increases postprandial triacylglycerol but decreases postprandial non-esterified fatty acid concentrations.

Plasma triacylglycerol concentrations increase after the acute ingestion of alcohol (specifically ethanol). However, the effect of ethanol when consumed with a mixed meal has not been well studied. The objective of the present study was to determine the perturbations of lipid metabolism that occur after ingestion of ethanol in combination with a mixed meal of specific fatty acid composition. Blood samples were taken from seven healthy male subjects before and after a mixed meal, with and without ethanol. The specific fatty acid composition of the test meal allowed the fatty acids to be traced into the plasma non-esterified fatty acid pool during the postprandial period. Statistical analysis by repeated measures ANOVA showed significant effects of ethanol. For example, postprandial lipaemia was enhanced after the ethanol test meal compared with the control (P < 0.05), mainly due to increases in triacylglycerol-rich lipoproteins in the flotation range Sf 60-400 (VLDL1) (P < 0.05); those in the range Sf 20-60 (VLDL2) and also Sf > 400 (chylomicrons) were not significantly affected. The later postprandial increase in plasma non-esterified fatty acid concentrations was reduced after the ingestion of ethanol (P < 0.001), but the proportions of palmitoleic acid (a marker of fatty acid content of the test meal) and of linoleic acid (a marker of endogenous lipolysis) were not affected. The results suggest a primary effect of ethanol on the stimulation of secretion of large VLDL particles, which then compete for clearance with chylomicrons by lipoprotein lipase. The results do not support an effect of ethanol on the release of non-esterified fatty acid into the plasma. The suppression of plasma non-esterified fatty acid concentrations during the postprandial period may contribute towards the beneficial effects of moderate ethanol consumption.

Adult↗

PubMed2000

TAP expression provides a general method for improving the recognition of malignant cells in vivo.

A major class of tumors lack expression of the transporters associated with antigen processing (TAP). These proteins are essential for delivery of antigenic peptides into the lumen of the endoplasmic reticulum (ER) and subsequent assembly with nascent major histocompatibility complex (MHC) class I, which results in cell surface presentation of the trimeric complex to cytolytic T lymphocytes. Cytolytic T lymphocytes are major effector cells in immunosurveillance against tumors. Here we have tested the hypothesis that TAP downregulation in tumors allows immunosubversion of this effector mechanism, by establishing a model system to examine the role of TAP in vivo in restoring antigen presentation, immune recognition, and effects on malignancy of the TAP-deficient small-cell lung carcinoma, CMT.64. To test the potential of providing exogenous TAP in cancer therapies, we constructed a vaccinia virus (VV) containing the TAP1 gene and examined whether VV-TAP1 could reduce tumors in mice. The results demonstrate that TAP should be considered for inclusion in cancer therapies, as it is likely to provide a general method for increasing immune responses against tumors regardless of the antigenic complement of the tumor or the MHC haplotypes of the host.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

Sudden infant death syndrome: hypothalamic failure to sense elevated blood pyrogens.

Sudden infant death syndrome (SIDS) is frequently associated with a mild infection, the incidence peaking during the third month of life. We hypothesize that the neonatal immaturity of both the acute febrile response and hypothalamus promote neonatal protection from SIDS. Vagal afferents modify the febrile response. Vagotomized rodents displayed a loss of febrile responsiveness in a 'non-sensing' brain. The failure of a 'non- sensing' brain to react to elevated blood pyrogens leads to failure of the febrile response and to a shock-like state. SIDS infants may appear well yet, within hours of this observation, may be found dead. There is a mismatch between the acute febrile response and hypothalamic hypoactivation. The discrepancy increase wtih development. There is an elevated cytokine response in endothelial cells which induces nitric oxide (NO) production and retarded development of the hypothalamus. Cigarette smoke also induces NO production and retards hypothalamic development by augmented apoptosis. Zinc inhibits this effect in mouse thymocytes. Fetal haemoglobin (HbF) induces hypoxia which is a stimulator of the immune response, while vasodilator gases (carbon monoxide (CO), NO) reduce hypothalamic function. The hypothalamic failure to sense elevated blood pyrogens induces toxic shock--a feature of SIDS.

Animals↗

PubMed2000

Association of sudden infant death syndrome with grossly deranged iron metabolism and nitric oxide overload.

Sudden infant death syndrome (SIDS) occurs silently usually during sleep and, though remaining unexplained after autopsy, leaves footprints creating a pattern analogous to that which follows a flood of nitric acid (NO). These footprints in SIDS are associated with serious pathological changes, viz. elevated hepatic iron, bone marrow hyperplasia, hypomyelinated respiratory control centres, elevated lung immunoglobulins, cerebral hypoperfusion resembling lesions induced by chronic hypoxemia, ischemia, congenital heart disease and congenital myopathy. Hypoxia stimulates the immune response and the over-arousal of the immune response triggers a flood of NO. Adenosine triggers sleep. NO and adenosine are additive as dilators of coronary blood vessels. Blood pressure collapses. Selenium increases the activity of the enzyme ferrochelatase during incorporation of heme into cytochrome oxidase. NO binds to cytochrome oxidase, inhibiting respiration. When NO reaches dangerous levels, the cell turns on production of heme oxygenase. Heme is broken down to iron (Fe) carbon monoxide (CO) and bile pigments. NO has a huge affinity for hemoglobin which catalyses NO degradation to nitrate. Furthermore, NO is a product of smoke and SIDS incidence is higher in smoking mothers.

Humans↗

PubMed2000

Specific toxins destabilize virus inhibitors (e.g. AIDS viruses).

There are two approaches to the study of viral infections - the A-Z hypothesis of Sprietsma involving thiol-zinc inhibition of protease activation in the virus coat, and the activity of toxins in depleting the cell of thiols, or the activity of toxins activating (not detoxifying) the mixed function oxidase (MFO) system. Both of these systems generate free radicals and utilize thiols in the process. Zinc forms stable mercaptides with thiols, inhibits cyclic reduction-autoxidation of thiols and superoxide generation. When the MFO system acts as an activator and not as a detoxifier in that intermediate products are more toxic than the original compound, zinc inhibits the oxidation. An example of increased toxicity with increased MFO activity is the toxin 3-methylindole (3-MI), a toxic product of intestinal bacterial putrefaction which reactivates the infectious bovine rhinotracheitis virus (IBR). Zinc reduces MFO activity and in this regard it functions synergistically with antioxidants in protecting cell membranes. It is hypothesized that stable zinc complexes inhibit activity of proteases in the virus nucleocapside (NC) proteins in the virus coat, both directly and indirectly because zinc also inactivates some toxins that are thiol depleters or virus reactivators.

Animals↗

PubMed2000

Physical fitness of adults with an intellectual disability: a 13-year follow-up study.

The purpose of this study was to describe the change in physical fitness of middle-aged adults with an intellectual disability over a period of 13 years. Participants were 32 adults who worked in a supported work environment in Montreal and had been participants in a physical fitness study in 1983. Using the Canadian Standardized Test of Fitness, the participants were evaluated for cardiovascular endurance, muscular strength, muscular endurance, flexibility, and body composition. A home visit prior to the testing session refamiliarized the participants with the test procedures. Two forms of analysis were used to describe the change in fitness over 13 years. First, a 2 x 2 (Group x Time) analysis of variance for each dependent variable assessed change over time. Second, effect sizes were calculated to measure the magnitude of change in fitness over the 13-year period in comparison to those without an intellectual disability. As expected, the physical fitness levels of the participants were low when compared to those without a disability and declined over the 13 years. In addition, the magnitude of change over the 13 years, as compared to those without a disability, was greater for male and female participants for body mass index and percentage of body fat and for female participants for cardiovascular endurance and sit-ups. It appears that adults with an intellectual disability may be particularly at risk for declining health associated with aging and low physical fitness.

Adipose Tissue↗

PubMed2000

Identification of collagen-binding proteins in Lactobacillus spp. with surface-enhanced laser desorption/ionization-time of flight ProteinChip technology.

Biosurfactants produced by Lactobacillus fermentum RC-14, L. rhamnosus GR-1 and 36, and L. casei Shirota were found to contain proteins that bind to both collagen types III and VI, as determined by surface-enhanced laser desorption/ionization (SELDI)-time of flight mass spectrometry. Both collagen types III and VI immobilized on SELDI preactivated ProteinChip arrays detected several different sizes (2 to 48 kDa) of collagen-binding proteins. Overall, the RC-14-produced biosurfactant contained the greatest number of collagen-binding proteins (RC-14 > GR-1 > 36 > Shirota), including the mature form of a previously cloned 29-kDa collagen-binding protein (referred to in its mature 26-kDa form). Although biosurfactants isolated from L. casei Shirota and L. rhamnosus 36 and GR-1 also contain several collagen-binding proteins, they do not contain the 26-kDa collagen-binding protein. Together, these results demonstrate the utility of the SELDI system as a means of rapidly characterizing clinically important but complex biosurfactant solutions.

Carrier Proteins↗

PubMed2000

Evaluation of new online automated embolic signal detection algorithm, including comparison with panel of international experts.

BACKGROUND AND PURPOSE: The clinical application of Doppler detection of circulating cerebral emboli will depend on a reliable automated system of embolic signal detection; such a system is not currently available. Previous studies have shown that frequency filtering increases the ratio of embolic signal to background signal intensity and that the incorporation of such an approach into an offline automated detection system markedly improved performance. In this study, we evaluated an online version of the system. In a single-center study, we compared its performance with that of a human expert on data from 2 clinical situations, carotid stenosis and the period immediately after carotid endarterectomy. Because the human expert is currently the "gold standard" for embolic signal detection, we also compared the performance of the system with an international panel of human experts in a multicenter study. METHODS: In the single-center evaluation, the performance of the software was tested against that of a human expert on 20 hours of data from 21 patients with carotid stenosis and 18 hours of data from 9 patients that was recorded after carotid endarterectomy. For the multicenter evaluation, a separate 2-hour data set, recorded from 5 patients after carotid endarterectomy, was analyzed by 6 different human experts using the same equipment and by the software. Agreement was assessed by determining the probability of agreement. RESULTS: In the 20 hours of carotid stenosis data, there were 140 embolic signals with an intensity of > or =7 dB. With the software set at a confidence threshold of 60%, a sensitivity of 85.7% and a specificity of 88.9% for detection of embolic signals were obtained. At higher confidence thresholds, a specificity >95% could be obtained, but this was at the expense of a lower sensitivity. In the 18 hours of post-carotid endarterectomy data, there were 411 embolic signals of > or =7-dB intensity. When the same confidence threshold was used, a sensitivity of 95.4% and a specificity of 97.5% were obtained. In the multicenter evaluation, a total of 127 events were recorded as embolic signals by at least 1 center. The total number of embolic signals detected by the 6 different centers was 84, 93, 108, 92, 63, and 78. The software set at a confidence threshold of 60% detected 90 events as embolic signals. The mean probability of agreement, including all human experts and the software, was 0.83, and this was higher than that for 2 human experts and lower than that for 4 human experts. The mean values for the 6 human observers were averaged to give P=0.84, which was similar to that of the software. CONCLUSIONS: By using the frequency specificity of the intensity increase occurring with embolic signals, we have developed an automated detection system with a much improved sensitivity. Its performance was equal to that of some human experts and only slightly below the mean performance of a panel of human experts

Algorithms↗

PubMed2000

Impact of preoperative education on pain management outcomes after coronary artery bypass graft surgery: a pilot.

Patients have been found to receive inadequate analgesia despite moderate to severe pain after coronary artery bypass graft (CABG) surgery. The purpose of this pilot study was to evaluate a preadmission educational booklet for patients undergoing their first uncomplicated CABG. A randomized controlled trial (RCT) was undertaken at the largest cardiovascular centre in Canada. Repeated measures were used to compare data from 3 interviews: at baseline, day 3, and day 5. Patients were randomly assigned to one of 3 groups at the preadmission clinic 2 to 7 days before surgery: (1) generic hospital booklet and videotape (control), (2) control + pain booklet, or (3) control + pain booklet and interview; 45 subjects completed all 3 interviews. Measures were the McGill Pain Questionnaire-Short Form and the American Pain Society Patient Outcome Questionnaire. For all groups, analgesic administration was inadequate (19.89[13.37] mg morphine equivalents/24 hours) despite unrelieved pain (6.63[2.46], 0-10). However, patients receiving the interventions in addition to control care received 46% more analgesia than patients receiving control care alone and had fewer concerns about asking for help and taking analgesia. Changes were not required in the intervention booklet or measures.

Adult↗