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Biomedical subjects

P McIntyre

Publications and source records attributed to P McIntyre.

At least 19 recordsLinked to original sources
PubMed2001

Pharmacological differences between the human and rat vanilloid receptor 1 (VR1).

Vanilloid receptors (VR1) were cloned from human and rat dorsal root ganglion libraries and expressed in Xenopus oocytes or Chinese Hamster Ovary (CHO) cells. Both rat and human VR1 formed ligand gated channels that were activated by capsaicin with similar EC(50) values. Capsaicin had a lower potency on both channels, when measured electrophysiologically in oocytes compared to CHO cells (oocytes: rat=1.90+/-0.20 microM; human=1.90+/-0.30 microM: CHO cells: rat=0.20+/-0.06 microM; human=0.19+/-0.08 microM). In CHO cell lines co-expressing either rat or human VR1 and the calcium sensitive, luminescent protein, aequorin, the EC(50) values for capsaicin-induced responses were similar in both cell lines (rat=0.35+/-0.06 microM, human=0.53+/-0.03 microM). The threshold for activation by acidic solutions was lower for human VR1 channels than that for rat VR1 (EC(50) pH 5.49+/-0.04 and pH 5.78+/-0.09, respectively). The threshold for heat activation was identical (42 degrees C) for rat and human VR1. PPAHV was an agonist at rat VR1 (EC(50) between 3 and 10 microM) but was virtually inactive at the human VR1 (EC(50)>10 microM). Capsazepine and ruthenium red were both more potent at blocking the capsaicin response of human VR1 than rat VR1. Capsazepine blocked the human but not the rat VR1 response to low pH. Capsazepine was also more effective at inhibiting the noxious heat response of human than of rat VR1.

Amino Acid Sequence↗
PubMed2000

Single blind, randomised trial of efficacy and acceptability of oral picolax versus self administered phosphate enema in bowel preparation for flexible sigmoidoscopy screening.

OBJECTIVE: To compare the acceptability and efficacy of two methods of self administered bowel preparation for flexible sigmoidoscopy screening: a single phosphate enema and a single sachet of Picolax. DESIGN: Single blind, randomised trial. SETTING: Endoscopy units of two general hospitals. PARTICIPANTS: 1442 men and women aged 55-64 years who had agreed to be screened by flexible sigmoidoscopy. MAIN OUTCOME MESURESs: Attendance rates, compliance with allocated preparations, adverse effects, quality of bowel preparation, procedure time, and yield of neoplasia. RESULTS: Compliance with the enema was higher than with the Picolax (608 (84%) v 566 (79%); difference 6%, 95% confidence interval 2% to 10%). Almost half of those who refused Picolax used an enema at home. Wind, incontinence, and sleep disturbance were more frequent in the Picolax group than the enema group; bottom soreness was more frequent in the enema group. Around 30% (187) found the diet restriction required by Picolax difficult; 78% (471) found the enema easy to administer. The quality of preparation was better with the enema; the proportion of procedures complete to the descending colon was greater and the mean duration of the procedure was shorter. There was no significant difference in polyp detection rates. CONCLUSION: A single phosphate enema self administered around one hour before leaving home is a more acceptable and effective method of preparing the distal bowel for flexible sigmoidoscopy than Picolax.

Administration, Oral↗
PubMed2000

Regulation of bradykinin receptor gene expression in human lung fibroblasts.

In WI-38 human fibroblasts, interleukin-1 beta and tumour necrosis factor-alpha (TNF-alpha) increased bradykinin B(1) receptor mRNA, which peaked between 2 and 4 h, remaining elevated for 20 h. Binding of the bradykinin B(1) receptor selective ligand [3H]des-Arg(10)-kallidin, also increased, peaking at 4 h and remaining elevated for 20 h. The B(max) value for [3H]des-Arg(10)-kallidin rose from 280+/-102 fmol/mg (n=3) to 701+/-147 fmol/mg (n=3), but the K(D) value remained unaltered (control, 1.04+/-0.33 nM (n=3); interleukin-1 beta, 0.88+/-0.41 nM (n=3)). The interleukin-1 beta-induced [3H]des-Arg(10)-kallidin binding sites were functional receptors, as bradykinin B(1) receptor agonist-induced responses increased in treated cells. Bradykinin B(2) receptor mRNA and [3H]bradykinin binding were upregulated by interleukin-1 beta, but not TNF-alpha. The effect of interleukin-1 beta on bradykinin B(2) receptors was smaller than for bradykinin B(1) receptors. Cycloheximide prevented interleukin-1 beta-mediated increases in B(1) and B(2) binding, but not mRNA suggesting that de novo synthesis of a transcriptional activator was unnecessary.

Binding, Competitive↗
PubMed2000

Differing serologic responses to an haemophilus influenzae type b polysaccharide-neisseria meningitidis outer membrane protein conjugate (PRP-OMPC) vaccine in australian aboriginal and caucasian infants - implications for disease epidemiology.

This study compared Hib antibody responses to a single lot of PRP-OMPC vaccine given at 2, 4 and 12 months to 57 Aboriginal infants in rural areas of the Northern Territory and 56 Caucasian infants in Sydney, Australia. The Aboriginal infants had lower levels of antibody in cord blood (P>0.05), which were significantly lower (P<0.02) by 2 months of age. Antibody responses to one or two doses of vaccine, measured at 4 and 12 months of age, were similar but the geometric mean titre following the booster dose in Aboriginal infants was significantly lower (1.98 vs. 6.04 mcg/ml, P = 0.002). Low preimmunisation antibody is consistent with the early onset of Hib disease in Aboriginal infants before immunisation. Lower responses to boosting could correlate with persistence of Hib colonisation in indigenous populations.

Age Factors↗
PubMed2000

The CD44v7/8 epitope as a target to restrain proliferation of fibroblast-like synoviocytes in rheumatoid arthritis.

CD44 is a receptor for the glycosaminoglycan hyaluronan. It exists in a large range of isoforms because of variability in the pattern of glycosylation (both N- and O-linked) and of multiple splice variants. Human fibroblast-like synoviocytes derived from patients with rheumatoid arthritis express certain CD44 splice variants and we have investigated the functional implications of their expression. We found that the rate of proliferation of fibroblast-like synoviocytes expressing the CD44v7/8 epitope (average doubling time 55 hours) exceeds those obtained from the same synovial specimen but lacking this particular epitope (69 hours). Antibodies against CD44v7/8, but not against other exons, inhibit cell proliferation with concomitant induction of the cell cycle inhibitors GADD45, GADD153 and the cyclin-dependent protein-kinase inhibitors p21Waf/Cip. These data show that expression of CD44v7/8 contributes to the transformed phenotype of fibroblast-like synoviocytes. More importantly, they reveal the presence of a target that might be amenable to pharmacological intervention in the treatment of rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed2000

Bradyzide, a potent non-peptide B(2) bradykinin receptor antagonist with long-lasting oral activity in animal models of inflammatory hyperalgesia.

Bradyzide is from a novel class of rodent-selective non-peptide B(2) bradykinin antagonists (1-(2-Nitrophenyl)thiosemicarbazides). Bradyzide has high affinity for the rodent B(2) receptor, displacing [(3)H]-bradykinin binding in NG108-15 cells and in Cos-7 cells expressing the rat receptor with K(I) values of 0.51+/-0.18 nM (n=3) and 0.89+/-0.27 nM (n=3), respectively. Bradyzide is a competitive antagonist, inhibiting B(2) receptor-induced (45)Ca efflux from NG108-15 cells with a pK(B) of 8.0+/-0.16 (n=5) and a Schild slope of 1.05. In the rat spinal cord and tail preparation, bradyzide inhibits bradykinin-induced ventral root depolarizations (IC(50) value; 1.6+/-0.05 nM (n=3)). Bradyzide is much less potent at the human than at the rodent B(2) receptor, displacing [(3)H]-bradykinin binding in human fibroblasts and in Cos-7 cells expressing the human B(2) receptor with K(I) values of 393+/-90 nM (n=3) and 772+/-144 nM (n=3), respectively. Bradyzide inhibits bradykinin-induced [(3)H]-inositol trisphosphate (IP(3)) formation with IC(50) values of 11.6+/-1.4 nM (n=3) at the rat and 2.4+/-0.3 microM (n=3) at the human receptor. Bradyzide does not interact with a range of other receptors, including human and rat B(1) bradykinin receptors. Bradyzide is orally available and blocks bradykinin-induced hypotension and plasma extravasation. Bradyzide shows long-lasting oral activity in rodent models of inflammatory hyperalgesia, reversing Freund's complete adjuvant (FCA)-induced mechanical hyperalgesia in the rat knee joint (ED(50), 0.84 micromol kg(-1); duration of action >4 h). It is equipotent with morphine and diclofenac, and 1000 times more potent than paracetamol, its maximal effect exceeding that of the non-steroidal anti-inflammatory drugs (NSAIDs). Bradyzide does not exhibit tolerance when administered over 6 days. In summary, bradyzide is a potent, orally active, antagonist of the B(2) bradykinin receptor, with selectivity for the rodent over the human receptor. British Journal of Pharmacology (2000) 129, 77 - 86

Administration, Oral↗
PubMed2000

Pertussis antibody levels in infants immunized with an acellular pertussis component vaccine, measured using whole-cell pertussis ELISA.

A commercially available whole-cell pertussis IgG ELISA was used to test the response of 137 2-month-old infants to immunization with a trivalent acellular pertussis vaccine. The pre-immunization geometric mean (GM) IgG index was 6.96 (95% confidence interval (CI) 5.88-8.04) and the postimmunization GM index was 13.16 (95% CI 12. 20-14.11), P < 0.001. Eighty percent of subjects (110/137) had a significant 1.5-fold increase of pertussis IgG index (97/137, 71%) or a postimmunization IgG index > 10 (93/137, 68%). In single antigen ELISA, 83% showed at least a fourfold increase in pertussis toxin-specific IgG (PT-IgG) and 91% showed an increase in IgG specific for filamentous haemagglutinin (FHA-IgG). Four percent had high pre- immunization antibody levels (index > 20), likely to reflect recent maternal exposure to pertussis. This correlated with a smaller increase in pertussis IgG index. A decline in pertussis IgG index postimmunization occurred in 17/24 infants (71%) whose pre-immunization IgG index was > 10. This postimmunization pertussis IgG index was not significantly different to that of infants with a low pre-immunization index. A similar trend was noted with PT-IgG and FHA-IgG results. The whole-cell ELISA can detect a response to acellular pertussis vaccination in most infants if both antibody index and degree of seroconversion are calculated and at least one criterion is satisfied.

Antibodies, Bacterial↗
PubMed2000

Abnormal spinal curvature and its relationship to pelvic organ prolapse.

OBJECTIVE: Intra-abdominal vector forces have been implicated in the development of genital prolapse. Because the normal spinal curvature appears to protect the pelvic cavity from direct upper abdominal forces, variations in spinal curvature may alter these vector forces and possibly potentiate the development of pelvic organ prolapse. This study was undertaken to evaluate the relationship of spinal curvature and pelvic organ prolapse, specifically, the loss of lumbar lordosis or pronounced thoracic kyphosis. STUDY DESIGN: A total of 363 patients referred for various complaints of urinary incontinence or pelvic organ prolapse were included in this multicenter, prospective, case-control study. All patients underwent a detailed history with site-specific examinations; pelvic organ prolapse was quantitatively assessed according to the POPQ (pelvic organ prolapse quantitation) staging system. Spinal curvature was measured with a flexi-curve malleable rod when patients were in a fully erect position. Spinal curvature was then transferred to graph paper by tracing the flexi-curve. Thoracic and lumbar curvatures were determined by measuring thoracic and lumbar lengths and widths, respectively. RESULTS: Ninety-two patients had abnormal spinal curvature according to the study criteria. Complete loss of lumbar lordosis was found in 69 patients. Of the 92 patients with an abnormal curvature, 84 currently had or previously had pelvic organ prolapse (sensitivity, 91%). When compared with patients with a normal curvature, patients with an abnormal spinal curvature were 3. 2 times more likely to have development of pelvic organ prolapse (odds ratio, 3.18; 95% confidence interval, 1.46 to 6.93; P =.002). There was no difference in the number of vaginal deliveries, weight of largest vaginally delivered infant, or body mass index. Only 11% (8/72) of patients with stage 0 prolapse had an abnormal spinal curvature, which increased to 30% (28/99) in patients with stage III prolapse (P =.042). CONCLUSION: An abnormal change in spinal curvature, specifically, a loss of lumbar lordosis, appears to be a significant risk factor in the development of pelvic organ prolapse.

Adult↗
PubMed2000

Surveillance of pneumococcal disease in Australian states and territories.

Information on pneumococcal disease, including immunisation programs, and optimum future surveillance in each Australian State and Territory were discussed at the Pneumococcal Disease in Australia Workshop on 26-27 March 1999. Workshop participants further expanded on the surveillance aspects of the Workshop in this report. Most participants favoured notification by laboratories of pneumococcal isolates from sterile sites, to provide baseline surveillance data before immunisation programs are fully implemented. It was also thought that trends in antimicrobial resistance should be notified.

Australia↗
PubMed2000

Post-transcriptional regulation of bradykinin B1 and B2 receptor gene expression in human lung fibroblasts by tumor necrosis factor-alpha: modulation by dexamethasone.

The cellular and molecular mechanisms governing bradykinin B1 and B2 receptor expression and function are poorly understood. We investigated the regulation of both B1 and B2 receptors in human embryonic lung fibroblasts (HEL 299) by the proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin 1beta (IL-1beta). TNF-alpha and IL-1beta both induced a rapid and transient increase in B1 and B2 receptor mRNA expression that was maximal by 2 h, accompanied by an increase in B1 and B2 receptor protein, as measured by radioligand binding assay with [(3)H]des-Arg(10)-kallidin, and [(3)H]bradykinin, respectively. The induced B1 receptors were functionally coupled, because the B1 agonist, des-Arg(10)-kallidin, induced an increase in arachidonic acid release in TNF-alpha-stimulated cells but not in control cells. The induction of B1 and the up-regulation of B2 receptors by TNF-alpha was partly mediated through activation of p38 mitogen-activated protein kinase and that of B2 receptor by protein kinase A. TNF-alpha and IL-1beta regulation of both B1 and B2 receptors was inhibited by dexamethasone. When compared with vehicle-treated cells, dexamethasone increased the rate of decline of both B1 and B2 receptor mRNAs. Nuclear run-on experiments demonstrate that the induction of B1 and the up-regulation of B2 receptors as well as the inhibitory effect of dexamethasone are entirely mediated through post-transcriptional mechanisms.

Anti-Inflammatory Agents↗
PubMed2000

Family Medicine residents' knowledge and attitudes about end-of-life care.

The medical management of end-of-life symptoms, and the psychosocial care of the dying and their families have not been a specific part of the curriculum for undergraduate medical students or residency training programs. The purpose of our research was to assess family medicine residents' knowledge of and attitudes toward care of the dying. All entering (PGY1) and exiting (PGY2) residents of the Dalhousie University Family Medicine Residency Program were given a 50-item survey on end-of-life care. They survey contains two 25-item subscales concerning attitudes/opinions toward end-of-life care, and knowledge about care. Thirty-one of the 33 entering PGY1s 94%) and 26 of the 30 exiting PGY2s (86%) completed the surveys. Overall attitude scores were felt to be high among both groups, with little difference between them. Areas of concern regarding the adequacy of knowledge were found in relation to managing opioid drugs and the symptom of dyspnea. Interventions are now in development to address these issues in the residency program. In an era of subspecialties, the challenge of integrating these areas into the curriculum without creating rotations in specialist palliative care is an issue faced by most family medicine residency programs.

Attitude of Health Personnel↗
PubMed1999

Australia's notifiable diseases status, 1998. Annual report of the National Notifiable Diseases Surveillance System.

In 1998 there were 85,096 notifications to the National Notifiable Diseases Surveillance System; slightly lower than in 1997 (89,579). The number of measles cases remained low, and well below the number reported in the outbreak years of 1993 and 1994. Rubella notifications further decreased and remained low in 1998. The Measles Control Campaign from August to November 1998, did not impact significantly on the number of measles or rubella cases reported for 1998. Notifications of Haemophilus influenzae type b reached a record low since surveillance began in 1991, and appeared to have stabilised at a low rate since the introduction of the conjugated vaccine in 1992. The previously reported outbreak of pertussis in 1997 tapered off in early 1998. Food-borne disease, or detection of disease, appeared to be on the rise with an increase in notification rates of campylobacteriosis and salmonellosis. Notifications of hepatitis A decreased, correcting the previous high number of notifications in 1997. Sexually transmissible diseases (STDs) increased. Notifications for chlamydial infection were the highest for all sexually transmitted diseases and third highest for all notifiable diseases. Notifications of gonococcal infection also continued to rise and have doubled since 1991, whilst notifications for syphilis increased slightly after falling steadily over recent years. Arbovirus infections of concern in 1998 were dengue outbreaks in Far North Queensland and the first case of Japanese Encephalitis for mainland Australia, highlighting the importance of surveillance of arboviruses and vectors for their detection and management.

Australia↗
PubMed1999

Glial cell line derived neurotrophic factor (GDNF) regulates VR1 and substance P in cultured sensory neurons.

Many nociceptive dorsal root ganglion (DRG) sensory neurons express the high affinity nerve growth factor (NGF) receptor TRKA, and respond to NGF. However, many do not express TRKA but are thought to respond to glial cell-derived neurotrophic factor (GDNF) and related molecules. We therefore cultured DRG neurons in the presence of GDNF, and looked at the expression of substance P and of the capsaicin receptor, VR1, two nociceptive properties already known to be NGF regulated. Using several different approaches we demonstrated that GDNF produced clear increases in expression of both properties, comparable in magnitude to increases seen with NGF. Following axotomy, aberrant expression of substance P in A fibres may be involved in the generation of neuropathic pain. Factors regulating substance P and other properties in the absence of retrogradely transported NGF may therefore be of significance in neuropathic pain states.

Animals↗
PubMed1999

Molecular characterisation of cloned bradykinin B1 receptors from rat and human.

This report describes the characterisation of cloned rat and human bradykinin B1 receptors in African green monkey kidney fibroblast (Cos-7) cells. A ligand binding assay with [3H]des-Arg10-kallidin was used to compare their pharmacology with respect to known bradykinin B1 and B2 receptor ligands. In addition, the pharmacology of T-kinin and its' derivative des-Arg11-T-kinin was investigated. The cloned rat receptor had a similar pharmacology to that of the recently described mouse receptor and differs from that described for the human receptor. The rat receptor had a higher affinity for des-Arg11-T-kinin than the human receptor. These differences in pharmacological properties may relate to the presence of T-kinin, bradykinin and their des-Arg derivatives as the major physiological peptides in rat and the predominance of kallidin and its derivatives in human. We confirm that the rat bradykinin B1 receptor gene is organised in a two exon structure and differs from the human gene which has a three exon structure and we further examine the inducible expression of this gene in a wide range of tissues using Northern blotting.

Amino Acid Sequence↗