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Biomedical subjects

P Conway

Publications and source records attributed to P Conway.

At least 19 recordsLinked to original sources
PubMed2001

Characterization of factors affecting attachment of Bifidobacterium species to amylomaize starch granules.

AIMS: Two human-derived Bifidobacterium strains, PL1 and PL2, were tested for their ability to attach to amylomaize starch granules, and factors affecting binding were assessed. METHODS AND RESULTS: Good binding to granules was observed when the strains were grown on maltose or amylomaize starch, but not on glucose. Binding activity was localized to cell wall components and was sensitive to treatment with proteolytic enzymes. Several methodologies were employed to confirm these observations, including studies using radiolabelled cells, dot blot assays and scanning electron microscopy (SEM) analysis. CONCLUSION: Results from this study indicated that binding of strains PL1 and PL2 to amylomaize starch granules was mediated by a cell wall-associated proteinaceous factor that was induced when the strains were grown on starch or a related substrate, but not glucose. SIGNIFICANCE AND IMPACT OF THE STUDY: Attachment of probiotic strains to starch or other dietary fibres is believed to offer a selective advantage in the host intestine and may even prolong viability in adverse food environments. Therefore, characterizing the mechanisms of attachment has commercial implications in the design of synbiotic products.

Bacterial Adhesion↗
PubMed2001

Association of Lactobacillus spp. with Peyer's patches in mice.

Sixteen strains of Lactobacillus isolated from humans, mice, and food products were screened for their capacity to associate with Peyer's patches in mice. In preliminary experiments, in vitro binding to tissue pieces was assessed by scanning electron microscopy, and it was demonstrated qualitatively that 5 of the 16 strains showed some affinity for the Peyer's patches, irrespective of their association with the nonlymphoid intestinal tissue. Lactobacillus fermentum KLD was selected for further study, since, in addition to its intrinsically high adhesion rate, this organism was found to exhibit a preferential binding to the follicle-associated epithelium of the Peyer's patches compared with its level of binding to the mucus-secreting regions of the small intestine. Quantitative assessment of scanning electron micrographs of tissue sections which had been incubated with L. fermentum KLD or a nonbinding control strain, Lactobacillus delbruckii subsp. bulgaricus, supported these observations, since a marked difference in adhesion was noted (P < 0.05). This preferential association of strain KLD with the Peyer's patches was also confirmed with radiolabeled lactobacilli incubated with intestinal tissue in the in vitro adhesion assay. Direct recovery of L. fermentum KLD from washed tissue following oral dosing of mice revealed a distinct association (P < 0.05) between this organism and the Peyer's patch tissue. In contrast, L. delbruckii subsp. bulgaricus showed negligible binding to both tissue types in both in vitro and in vivo adhesion assays. It was concluded that L. fermentum KLD bound preferentially to Peyer's patches of BALB/c mice.

Animals↗
PubMed2001

Analysis of the efficacy of pediatric day surgery.

OBJECTIVES: To assess the efficacy and safety of a pediatric day surgery program and its benefits to the child and family. DESIGN: A review and analysis of prospectively gathered data. SETTING: The Children's Hospital of Eastern Ontario (CHEO), a university-affiliated pediatric centre with a referral base of 2.5 million people. PATIENTS: All children undergoing day surgery at CHEO during the 5 years between 1992 and 1997. INTERVENTIONS: All surgical procedures performed on a day surgery basis. MAIN OUTCOME MEASURES: Procedures performed, complications and unexpected admissions. RESULTS: An average of 4,899 children per year underwent surgical procedures in the ambulatory day surgery program. The 4 commonest procedures performed were myringotomy, tonsillectomy and adenoidectomy, dental procedures, and inguinal hernia repair. The majority of children were between 2 and 7 years of age. Complications were few, averaging 1.6% per year, with postoperative bleeding, primarily secondary to tonsillectomy and adenoidectomy, being the most common. None resulted in permanent disability and there were no deaths. CONCLUSIONS: Pediatric day surgery is a safe and cost-effective program that benefits the child, the family and the pediatric surgical program.

Adolescent↗
PubMed1998

Simultaneous kidney pancreas transplantation: patient issues and nursing interventions.

Nursing care across the service delivery continuum is essential for patients undergoing simultaneous kidney pancreas transplantation. The self-management of complicated treatment choices and care regimens requires education and support, which are the domain of transplant nursing coordinators. Even successful transplantation is associated with complications in the first 6 months. Continuous posttransplant nursing interventions to monitor patients, teach and reinforce self-care, and support adjustment is crucial to patient well-being. This article describes nursing strategies used at one transplant center to address these patient needs.

Family↗
PubMed1997

Peripheral vascular disease after kidney-pancreas transplantation in diabetic patients with end-stage renal disease.

OBJECTIVE: To determine the long-term effect of a functioning pancreas transplant on peripheral vasculopathy. DESIGN: We compared the progression of peripheral vascular disease in 39 recipients of successful kidney-pancreas transplants (KPT) with 65 consecutive diabetic patients who received cadaver kidney transplants alone (KTA) during the same period in a nonrandomized, retrospective control study. The mean duration of follow-up was more than 4 years in both groups. SETTING: Academic subspecialty referral practice. PATIENTS: A consecutive sample of all KPT recipients with more than 6 months of pancreas allograft function performed between May 1, 1988, and April 30, 1995. All patients who received cadaver renal transplants for diabetic nephropathy during the same period and who maintained a functioning renal allograft for more than 6 months were included as controls. INTERVENTION: Kidney-pancreas transplantation. MAIN OUTCOME MEASURE: Progression of peripheral vascular complications (PVC) defined as any midfoot or limb amputation (AMP), any ischemic ulceration requiring treatment (ULCER), and lower-extremity bypass surgery or angioplasty (LEBP). Ulcers leading to amputation were considered as single events (AMP only). RESULTS: Thirty-five (90%) of 39 KPT recipients are insulin-free. The KTA recipients had more atherosclerotic risk factors, including a higher incidence of coronary artery disease (P = .008), higher serum cholesterol levels (P = .03), and higher triglyceride levels (P = .04) than KPT recipients. Peripheral vascular complications before transplantation were comparable (P = .94) between groups. After transplantation, there were 35 new PVC (9 AMP, 11 ulcers, and 15 LEBP) in 18 of 39 KPT recipients vs 32 PVC (10 AMP, 8 ulcers, and 14 LEBP) in 20 of 65 KTA recipients (P = .005), indicating that KPT recipients had more PVC than did KTA recipients, despite a functioning pancreas. Seven bypass grafts failed after KPT, resulting in 6 limb amputations. In contrast, only 3 limb amputations were performed in 14 patients undergoing lower-extremity bypass procedures after KTA. CONCLUSIONS: Despite fewer risk factors for peripheral vasculopathy and the presence of insulin independence, KPT recipients had a higher incidence of PVC than a cohort of uremic diabetic patients undergoing KTA during the same period. These data show that a functioning pancreas allograft performed with a renal transplantation not only does not alter the progression of peripheral vascular disease in patients with renal failure secondary to diabetic nephropathy but also may accelerate PVC.

Adult↗
PubMed1997

Measurements of vertebral translations using bone pins, surface markers and accelerometers.

OBJECTIVE: To compare invasive and non-invasive techniques for measuring the posterior-to-anterior translations of vertebrae during spinal manipulative therapy. DESIGN: This study represents a small part of a larger experiment. BACKGROUND: Despite the mechanical nature of spinal manipulative therapy, the mechanism by which it alleviates back pain is still unknown. An understanding of the deformation behaviour of the spine during spinal manipulative therapy would aid in the formulation of a hypothesis underlying its efficacy. METHODS: A clinician delivered posterior-to-anterior manipulative thrusts to the right transverse process of either T(10), T(11) or T(12) in two cadavers. Posterior-to-anterior translations of the bone pins and surface markers (embedded in and taped over T(10), T(11) and T(12), respectively) were recorded by cine cameras. Posterior-to-anterior accelerations, recorded by the accelerometers, were used to calculate posterior-to-anterior translations. Translation measurements made by using the surface markers and the accelerometers were compared to those made by using the bone pins. RESULTS: There were no significant differences between the posterior-to-anterior translations of vertebrae obtained from the surface markers, as compared to the bone pins. The accelerometers underestimated the absolute, and overestimated the relative, vertebral translations, respectively, compared to the bone pins. CONCLUSIONS: The translations measured by the surface markers were more similar to the translations derived from the bone pins than those calculated from the accelerometers. Three-dimensional surface marker arrays would therefore be more useful to determine all relative movements non-invasively.

Journal Article↗
PubMed1995

A single-center experience with six-antigen-matched kidney transplants.

OBJECTIVES: To review our center's experience with the United Network of Organ Sharing six-antigen-matched (6-AgM) kidney program. Specifically, to determine whether recipients of 6-AgM cadaver kidney transplants have less perioperative and short-term (< 1 year) morbidity in comparison with living-related donor (LRD) recipients and a control group of immunologically less well-matched cadaver recipients. DESIGN: A retrospective review of all solitary kidney transplantations performed over a 24-month period, from 1992 to 1993. SETTING: A large urban tertiary care referral center with a long history of renal and extrarenal transplantation. PATIENTS: Adult patients receiving a solitary kidney transplant from either a cadaver or a living donor. MAIN OUTCOME MEASURES: Mortality, morbidity, and patient and graft survival. Other variables measured included rejection episodes, length of stay, readmissions, postoperative complications, waiting time, and delayed postoperative graft function. RESULTS: Recipients of 6-AgM kidney transplants were at higher risk than the control groups of cadaver and LRD recipients, with more retransplantations, higher sensitization, and more with diabetes. There were fewer rejection episodes in the 6-AgM group, and these were more steroid responsive. They had fewer hospital days (22.6 days) in the first year following transplantation, compared with the remaining cadaver group (28 days). The delayed postoperative graft function rate was also significantly lower than that of the cadaver control group. Graft and patient survival were excellent for all groups. Analysis of these factors showed similar results when comparing the LRD and 6-AgM groups and a marked improvement over the cadaver control group. CONCLUSIONS: Identical HLA matching for cadaver recipients provides superior results for graft and patient survival. There is much less perioperative morbidity in comparison with the less well-matched cadaver recipients. The effect of HLA matching is reflected in the perioperative courses of these patients, in addition to the long-term benefits of graft survival. Allograft survival is superior for this select group of cadaver recipients. The 6-AgM recipients behave similarly to LRD recipients in this cohort of patients. Our results would support the continued sharing of 6-AgM kidneys to optimize outcome and best use the limited resources available to the patients undergoing transplantation.

Adult↗
PubMed1995

Presence of F107, 2134P and Av24 fimbriae on strains of Escherichia coli isolated from Swedish piglets with diarrhoea.

A total of 109 Escherichia coli isolates from piglets with diarrhoea, that had previously been shown to be enterotoxin producers, but negative for the adhesive fimbriae K88, K99, 987P and F41 were tested for the presence of more recently characterised fimbriae. Testing was done by immunodot assay with absorbed polyclonal antisera against Av24 and F107 fimbriae, and unabsorbed polyclonal antiserum and monoclonal antiserum against 2134P fimbriae. Strains were also tested by polymerase chain reaction for the presence of genes encoding the major subunit of F107 fimbriae. After elimination of possible non-specific reactions, antisera testing produced 10 strains positive with all 4 antisera, 1 strain that reacted with all antisera except F107, 2 strains that reacted with all antisera except the 2134P monoclonal, 3 strains that reacted with 2134P polyclonal and F107 and 2 that reacted with F107 only. The PCR testing confirmed the results of the antisera, but also produced an additional 14 positive strains, giving a total of 30% of the strains tested reacting positively by PCR. Furthermore, all 33 isolates positive by PCR came from pigs that were older than 1 week, which is 45% of the 72 isolates tested which came from older pigs.

Animals↗
PubMed1995

Development of a PCR-based technique for detection of Helicobacter pylori.

A primer-set was designed for specific detection of genes that encode for 16S rRNA of Helicobacter pylori, using direct polymerase chain reaction (PCR). The primers were selected in the hypervariable regions, derived from a complete small subunit 16S rRNA sequence of the reference strain H. pylori CCUG 17874. The primer-set amplified a 537 base pair (bp) sequence specifically from chromosomal H. pylori DNA. Amplification of purified chromosomal H. pylori DNA was achieved at concentrations as low as 1 femto gram (fg), equivalent to 5 bacteria. Furthermore, as few as 1 lysed H. pylori cell was detected by this PCR technique. The specificity of the primers was 100%, since purified chromosomal DNA was detected from all 32 various H. pylori isolates, whereas no other bacteria species were detected, whether related to Helicobacter or not. The 16S rDNA primers successfully detected H. pylori in antral biopsy specimens collected from infected patients.

Adult↗
PubMed1993

Bromodeoxyuridine-labelled apoptosis after treatment with antimetabolites in two murine tumours and in small intestinal crypts.

Antimetabolites are S-phase specific anticancer drugs. Administration of bromodeoxyuridine (BrdUrd) to tumour bearing mice was followed by treatment with cytosine arabinoside or hydroxyurea. Anti-BrdUrd immunocytochemistry visualised susceptible tumour and intestinal crypt cells at electron microscope level, showing unequivocally that cells that were in S-phase at the time of administration of the drugs subsequently died by apoptosis.

Animals↗
PubMed1992

Prognosis for breast cancer surgery and radiation therapy compared with mastectomy alone. A retrospective analysis of 759 patients with stage I/II breast cancer.

Seven hundred fifty-nine patients with Stage I/II breast cancer who were treated with mastectomy alone (558 patients) or breast-conserving surgery and tangential irradiation (201 patients) were evaluated. Median follow-up time was 34 months. Axillary node status showed differences between treatment groups. Seventy-two percent of patients undergoing lumpectomy and radiation therapy (Lx) versus 35% of patients in the mastectomy group were pathologically node-negative, 18% Lx versus 30% mastectomy alone had one to three nodes positive, and four or more positive axillary nodes were seen in 35% of mastectomy alone patients. Reflecting this trend, overall survival (P less than 0.007), time to locoregional failure (P less than 0.0005), and time to any failure (P less than 0.0001) favored Lx patients. Correcting for axillary node status, significant differences persisted only for node-negative patients. Median actuarial survival time was 73 months for the mastectomy alone group (196 patients) versus 120 months for the Lx group (144 patients) (P less than 0.02), with significant differences also noted in time to local failure (P less than 0.003) and time to any failure (P less than 0.001). Stratification according to primary tumor size in patients who were node-negative yielded marked differences in time to locoregional failure in T1 (less than 2 cm) (P less than 0.0006) presentations, with analysis approaching significance for T2 (2 to 5 cm) lesions (P less than 0.06). Disease-free interval was greater in node-negative Lx patients for both T1 (P less than 0.007) and T2 (P less than 0.05) presentations. Overall survival was not significantly different in node-negative Lx patients when primary tumor size was considered. Improved prognosis was identified in node-negative patients undergoing breast-conserving surgery and radiation therapy over mastectomy alone. Theoretical considerations included eradication of occult microscopic disease within the chest wall by tangential irradiation.

Adult↗
PubMed1992

Radiation therapy in a case of systemic mastocytosis: evaluation of histamine levels and mucosal effects.

Plasma histamine levels were obtained during palliative radiation therapy of the spine involved with systemic mastocytosis in a 68-year-old woman. Baseline plasma histamine levels were obtained before irradiation and compared to levels obtained on the third, fifth, eighth, and tenth treatment days. Despite concerns regarding histamine release with mast cell destruction following irradiation, plasma histamine levels remained within normal limits. No change in dermatologic or other systemic manifestations were observed. No untoward systemic or localized sequelae associated with mast cell degranulation in response to the administered large field of radiation was observed. Effective palliation was accomplished, and it was concluded that radiation therapy can effectively be applied in treatment of systemic mast cell disease without significant morbidity.

Aged↗
PubMed1989

Inhibition by antibiotics of the bacterial response to long-term starvation of Salmonella typhimurium and the colon microbiota of mice.

The number of viable cells of two strains of Salmonella typhimurium and the number of viable cells and the cell size of the colon microbiota of mice were examined during non-growing conditions after exposure to antibiotics with known modes of action. Salmonella typhimurium starved for 1, 2, 4, 5, 12 and 20 d in a phosphate buffer saline solution and subsequently exposed for 2 and 6 h showed the following characteristics. The protein synthesis inhibitors gentamicin and tetracycline, the RNA synthesis inhibitor rifampicin and the membrane potential inhibitor polymyxin all impaired survival of starved cells. The reduction in the number of viable cells caused by the addition of gentamicin, rifampicin and polymyxin was generally more pronounced with extended exposure to energy and nutrient deprivation. Both 2- and 6-h exposure of tetracycline, however, had diminishing inhibitory effects after 20 d compared with 5 d of starvation. Control experiments to verify non-growing conditions in the starvation regime showed that DNA and cell wall synthesis inhibitors had no inhibitory effect after 24-h starvation. The rough mutant strain displayed a lower sensitivity to a hydrophobic rather than a hydrophilic inhibitor as compared to the smooth wild-type strain. The cell size reduction but not viability was partly prevented by protein synthesis inhibitors as seen for both in vivo and in vitro colon microbiota studies.

Animals↗