[Partially French Canadians are susceptible to increased cardiovascular risk factors: A population-based retrospective cohort study]. / Les Canadiens partiellement Français sont susceptibles à une augmentation des facteurs de risque cardiovasculaire : une étude de cohorte rétrospective basée sur la population.

BACKGROUND: Through various research lead in the past, it has been made evident that Quebec is home to higher rates of acute myocardial infarction (AMI) and higher prevalence of cardiovascular risk factors than other Canadian provinces. This proposed study will perform a retrospective analysis on Caucasian populations in order to analyze the cardiovascular risk factors in partially francophone populations in comparison to French and Non-French Canadians. Furthermore, we will closely analyze both genders of aforementioned populations. METHODS: This population-based retrospective cohort study was achieved using the University of Ottawa Heart Institute CCTA registry. Included are Caucasian patients of all ages who came to UOHI for a CCTA between 2006 and 2018 and provided written informed consent. SPSS was used to compare the different populations (French Canadian, partially French Canadian and non-French Canadian) and sex. RESULTS: The PFC population more closely resembles FC, having higher incidence of cardiovascular risk factors such as smoking, dyslipidemia and type 2 diabetes. INTERPRETATION: Our results suggest that PFC, like FC, may benefit from more intensive education and lifestyle modification techniques.

Pharmacological Actions of Glucagon-Like Peptide-1, Gastric Inhibitory Polypeptide, and Glucagon.

Glucagon family of peptide hormones is a group of structurally related brain-gut peptides that exert their pleiotropic actions through interactions with unique members of class B1 G protein-coupled receptors (GPCRs). They are key regulators of hormonal homeostasis and are important drug targets for metabolic disorders such as type-2 diabetes mellitus (T2DM), obesity, and dysregulations of the nervous systems such as migraine, anxiety, depression, neurodegeneration, psychiatric disorders, and cardiovascular diseases. The current review aims to provide a detailed overview of the current understanding of the pharmacological actions and therapeutic advances of three members within this family including glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP), and glucagon.

Molecular cloning and mRNA distribution of pituitary adenylate cyclase-activating polypeptide (PACAP)/PACAP-related peptide in the lungfish.

In this article, we report the isolation of a full-length cDNA clone encoding pituitary adenylate cyclase-activating polypeptide (PACAP)/PACAP-related peptide (PRP) from lungfish Protopterus dolloi. When comparing the deduced amino acid sequences, the lungfish PACAP was found to be highly conserved with other vertebrates; however, the PRP shares only lower levels of sequence identity with known PRP sequences. Consistently in phylogenetic analysis, the lungfish PRP, similar to sturgeon PRP, fails to cluster with other PRPs. In addition to the full-length clone, another cDNA encoding a short precursor that lacks the first 32 amino acids of the PRP was also isolated. Interestingly, similar isoforms were also identified in several nonmammalian vertebrates, and it was suggested that exon skipping of PRP/PACAP transcripts was a mechanism that regulated the expression ratio of PACAP to PRP in nonmammalian vertebrates. By real-time PCR, both long and short PRP/PACAP transcripts were found almost exclusively in the brain, and the short isoform is the more abundant transcript (3.7 times more), indicating that PACAP is the major product produced in lungfish brain. The expression patterns of lungfish and previously studied frog PRP/PACAP suggest that the PRP/PACAP gene in the tetrapod lineage may first express in the central nervous system; in the process of evolution, the functions of these peptides diversified and were later found in other tissues.

Comparison between sevoflurane/remifentanil and propofol/remifentanil anaesthesia in providing conditions for somatosensory evoked potential monitoring during scoliosis corrective surgery.

Somatosensory evoked potential (SSEP) monitoring is an important tool in spinal corrective surgery. Anaesthesia has a significant influence on SSEP monitoring and a technique which has the least and shortest suppressant effect on SSEP while facilitating a fast recovery from anaesthesia is ideal. We compared the effect of sevoflurane/ remifentanil and propofol/remifentanil anaesthesia on SSEPs during scoliosis corrective surgery and assessed patients' clinical recovery profiles. Twenty patients with idiopathic scoliosis receiving surgical correction with intraoperative SSEP monitoring were prospectively randomised to receive sevoflurane/remifentanil anaesthesia or propofol/remifentanil anaesthesia. During surgery, changes in anaesthesia dose and physiological variables were recorded, while SSEP was continuously monitored. A simulated 'wake-up' test was performed postoperatively to assess speed and quality of recovery from anaesthesia. The effects of propofol and sevoflurane resulted in SSEP amplitude variability between 18.0% +/- 3.5% to 28.7% +/- 5.9% and SSEP latency variability within 1.3% +/- 0.4% to 2.6% +/- 1.2%. Patients receiving sevoflurane had faster suppression and faster recovery of SSEP amplitude compared to propofol (P < 0.05), although propofol anaesthesia showed less within-patient variability in Cz amplitude and latency (P < 0.05). On cessation of anaesthesia, time to eye-opening (5.2 vs. 16.5 minutes) and toe movement (5.4 vs. 17.4 minutes) was shorter following sevoflurane (all P < 0.05). These findings indicate that propofol produces a better SSEP signal than sevoflurane. However adjustments in sevoflurane concentration result in faster changes in the SSEP signal than propofol. Assessment of neurological function was facilitated more rapidly after sevoflurane anaesthesia.

Persistent pain in patients following scoliosis surgery.

Chronic or persistent pain is increasingly recognised as a consequence of surgery in a number of different disciplines. The pain often exhibit qualities that differ from the acute post-operative pain and may represent changes in the central nervous system. There is lack of information regarding the incidence of persistent pain in patients following spinal surgery for scoliosis. This study aims to estimate the incidence of persistent pain following spinal surgery for scoliosis in a group of mainly adolescent patients. Questionnaires were distributed to consecutive patients attending the outpatient clinic of a hospital with specialist services in paediatric orthopaedics and spinal surgery. One hundred and five patients out of 122 eligible patients completed the survey. Fifty-two percent had ongoing pain upon hospital discharge either in the primary surgical site and/or in the iliac bone graft site. Approximately 10 and 7% of all patients had back and pelvic pain persisting beyond 12 months, respectively. A small proportion described elements of neuropathic pain. There was a trend suggesting that those who experienced more severe post-operative pain were more likely to develop persistent pain. These data are consistent with those reports that implicate surgery as the trigger for chronic pain.

Latent membrane protein 1 suppresses RASSF1A expression, disrupts microtubule structures and induces chromosomal aberrations in human epithelial cells.

Epstein-Barr virus (EBV) infection is closely associated with nasopharyngeal carcinoma (NPC) and can be detected in early premalignant lesions of nasopharyngeal epithelium. The latent membrane protein 1 (LMP1) is an oncoprotein encoded by the EBV and is believed to play a role in transforming premalignant nasopharyngeal epithelial cells into cancer cells. RASSF1A is a tumor-suppressor gene commonly inactivated in many types of human cancer including NPC. In this study, we report a novel function of LMP1, in down-regulating RASSF1A expression in human epithelial cells. Downregulation of RASSF1A expression by LMP1 is dependent on the activation of intracellular signaling of NF-kappaB involving the C-terminal activating regions (CTARs) of LMP1. LMP1 expression also suppresses the transcriptional activity of the RASSF1A core promoter. RASSF1A stabilizes microtubules and regulates mitotic events. Aberrant mitotic spindles and chromosome aberrations are reported phenotypes in RASSF1A inactivated cells. In this study, we observed that LMP1 expression in human epithelial cells could induce aberrant mitotic spindles, disorganized interphase microtubules and aneuploidy. LMP1 expression could also suppress microtubule dynamics as exemplified by tracking movements of the growing tips of microtubules in live cells by transfecting EGFP-tagged EB1 into cells. The aberrant mitotic spindles and interphase microtubule organization induced by LMP1 could be rescued by transfecting RASSF1A expression plasmid into cells. Downregulation of RASSF1A expression by LMP1 may facilitate its role in transformation of premalignant nasopharyngeal epithelial cells into cancer cells.

Severe hypotension and hepatic dysfunction in a patient undergoing scoliosis surgery in the prone position.

Many patients with neuromuscular disorders develop progressive scoliosis and require corrective surgery. We present a patient with hereditary motor and sensory neuropathies who developed severe hypotension during corrective surgery for thoracolumbar scoliosis. The haemodynamic disturbance was probably secondary to thoracic hyperlordosis and the knee-chest position and was aggravated by surgical manipulation. This may be prevented by tailored preoperative evaluation of different patient prone position supports and frames in order to select that which causes least cardiovascular and respiratory disturbance. This patient also developed severely deranged liver function postoperatively and the possible aetiology is discussed.

Secretin controls anion secretion in the rat epididymis in an autocrine/paracrine fashion.

There is growing evidence that secretin, the first hormone discovered in our history, has functions in the brain other than in the gastrointestinal tract. This article reports for the first time that secretin and its receptor mRNAs are produced in distinct cell types within the epididymis. To test if secretin affects electrolyte transport in the epididymis, we measured short-circuit current (Isc) in cultured epididymal epithelia and found secretin dose-dependently stimulated Isc. Ion substitution experiments and use of pharmacological agents inferred that the stimulated Isc is a result of concurrent electrogenic chloride and bicarbonate secretion. It is further shown that secretin and pituitary adenylate cyclase-activating polypeptide (PACAP) function via totally different mechanisms: 1) PACAP works only from the apical side of the epithelium to stimulate chloride and not bicarbonate secretion, while secretin acts on the apical and basolateral sides to stimulate chloride and bicarbonate secretion. 2) the stimulation by PACAP but not secretin requires local prostaglandin synthesis. By immunocytochemical staining, secretin is localized in the principal cells of the initial segment and caput epididymidis, whereas secretin receptor is present in the principal cells of the proximal as well as the distal part of the epididymis. This pattern of distribution appears to be consistent with the idea that secretin is secreted by the proximal epididymis and acts on the proximal and distal epididymis in an autocrine and paracrine fashion. Its function is to control secretion of electrolytes and water.

An autologous blood donation program for paediatric scoliosis patients in Hong Kong.

A retrospective audit was conducted to determine the safety, efficacy and patient satisfaction related to a preoperative autologous blood donation program for children and teenagers undergoing corrective surgery for scoliosis. Forty-five of the 77 patients donated the requested amount of blood. These 45 compliant patients had been requested to donate fewer units of blood than noncompliant patients (mean 4.0 vs 4.6 respectively, P = 0.02). Twelve patients required allogeneic blood transfusion. Two patients had surgery delayed making the collected autologous blood unavailable. The extent of the operation was associated with the need for allogeneic blood transfusion. Six and a half percent of all donated units of blood were discarded. No major complications were reported. Overall, 93% of patients were satisfied with the program. With careful patient selection, good inter-departmental coordination and teamwork, preoperative autologous blood donation in paediatric patients undergoing extensive corrective surgery for scoliosis is safe and effective.

Effect of sevoflurane/nitrous oxide versus propofol anaesthesia on somatosensory evoked potential monitoring of the spinal cord during surgery to correct scoliosis.

BACKGROUND: Use of intraoperative somatosensory evoked potential (SSEP) monitoring is helpful in spinal corrective surgery but may be affected by anaesthetic drugs. An anaesthetic technique that has less effect on SSEP or allows faster recovery is an advantage. We compared the effects on SSEP and the clinical recovery profiles of sevoflurane/nitrous oxide and propofol anaesthesia during surgery to correct scoliosis. METHODS: Twenty adolescent patients were randomized into two groups of 10. One group received sevoflurane-nitrous oxide anaesthesia and the other received propofol i.v. anaesthesia. An alfentanil infusion was used for analgesia in both groups. RESULTS: Changes in anaesthetic concentration produced little effect on the latency of SSEP, but the effect on the variability of SSEP amplitude was significant (P<0.05). Sevoflurane produced a faster decrease in SSEP and a faster recovery than propofol (P<0.05). On emergence, patients who received sevoflurane tended to have shorter recovery times to eye opening (mean 5.1 vs 20.6 min, P=0.09) and toe movement (mean 7.9 vs 15.7 min, P=0.22). Those who had received sevoflurane were significantly more lucid and cooperative in recovery. CONCLUSIONS: Sevoflurane produces a faster decrease and recovery of SSEP amplitude as well as a better conscious state on emergence than propofol.

Application of SFHR to gene therapy of monogenic disorders.

Gene therapy treatment of disease will be greatly facilitated by the identification of genetic mutations through the Human Genome Project. The specific treatment will ultimately depend on the type of mutation as different genetic lesions will require different gene therapies. For example, large rearrangements and translocations may call for complementation with vectors containing the cDNA for the wild-type (wt) gene. On the other hand, smaller lesions, such as the reversion, addition or deletion of only a few base pairs, on single genes, or monogenic disorders, lend themselves to gene targeting. The potential for one gene targeting technique, small fragment homologous replacement (SFHR) to the gene therapy treatment of sickle cell disease (SCD) is presented. Successful conversion of the wt-beta-globin locus to a SCD genotype of human lymphocytes (K562) and progenitor/stem hematopoietic cells (CD34(+) and lin-CD38-) was achieved by electroporation or microinjection small DNA fragments (SDF).

Pituitary growth hormone secretion in the turbot, a phylogenetically recent teleost, is regulated by a species-specific pattern of neuropeptides.

In mammals, growth hormone (GH) is under a dual hypothalamic control exerted by growth hormone-releasing hormone (GHRH) and somatostatin (SRIH). We investigated GH release in a pleuronectiform teleost, the turbot (Psetta maxima), using a serum-free primary culture of dispersed pituitary cells. Cells released GH for up to 12 days in culture, indicating that turbot somatotropes do not require releasing hormone for their regulation. SRIH dose-dependently inhibited GH release up to a maximal inhibitory effect of 95%. None of the potential stimulators tested induced any change in basal GH release. Also, neither forskolin, an activator of adenylate cyclase, nor phorbol ester (TPA), an activator of protein kinase C, were able to modify GH release, suggesting that spontaneous basal release already represents the maximal secretory capacity of turbot somatotropes. In contrast, forskolin and TPA were able to increase GH release in the presence of SRIH. In this condition (coincubation with SRIH), pituitary adenylate cyclase-activating polypeptide (PACAP) stimulated GH release, whereas none of the other neuropeptides tested (GHRHs; sea bream or salmon or chicken II GnRHs; TRH; CRH) had any significant effect. These data indicate that inhibitory control by SRIH may be the basic control of GH production in teleosts and lower vertebrates, while PACAP may represent the ancestral growth hormone-releasing factor in teleosts, a role taken over in higher vertebrates by GHRH.

Identification of a proglucagon cDNA from Rana tigrina rugulosa that encodes two GLP-1s and that is alternatively spliced in a tissue-specific manner.

Glucagon plays a pivotal role in the regulation of metabolism. A glucagon receptor has been previously characterized in the frog, Rana tigrina rugulosa, and the frog and human glucagon receptors have been shown to possess similar binding affinities toward human glucagon. To study the structural evolution of glucagon peptide and its receptor in vertebrates, in the current study, a proglucagon cDNA from the same frog species was cloned. Interestingly, in contrast to the mammalian proglucagons that contain only one GLP-1 peptide, the frog proglucagon cDNA encodes two GLP-1 peptides (GLP-1A and GLP-1B) in addition to a glucagon peptide and a glucagon-like peptide 2 (GLP-2). By reverse transcriptase-PCR (RT-PCR) analysis, the proglucagon gene expression was widely detected in the brain, colon, small intestine, liver, lung, and pancreas, suggesting that the proglucagon-derived peptides have diverse functions in frogs. Moreover, tissue-specific alternative mRNA splicing was observed in the brain, colon, and pancreas. In these tissues, proglucagon transcripts with a 135 bp in frame deletion encoding GLP-1A were found. This splicing event in R. tigrina rugulosa is novel because it deletes a GLP-1 encoding sequence instead of the GLP-2 observed in other vertebrates. These findings should enhance understanding of the proglucagon evolution, structure, and expression in vertebrates.

Structural and functional identification of the pituitary adenylate cyclase-activating polypeptide receptor VPAC2 from the frog Rana tigrina rugulosa.

Recently, a frog pituitary adenylate cyclase-activating polypeptide (PACAP)/vasoactive intestinal peptide (VIP) receptor (fPVR) has been characterized, and interestingly, this receptor exhibits characteristics of both mammalian PACAP type II receptors VPAC(1)R and VPAC(2)R. In order to investigate the receptors responsible for mediating the actions of VIP and PACAP in amphibians, in this report, a frog VPAC(2) receptor (fVPAC(2)R) cDNA was isolated. fVPAC(2)R shares 47.7, 46.9 and 62.5% amino acid sequence identity with fPVR, human VPAC(1)R and human VPAC(2)R respectively. Functionally, fVPAC(2)R, when expressed in CHO cells, was responsive to both frog peptides including VIP, PACAP38 and PACAP27 where the EC(50) values of these peptides in intracellular cAMP production were 0.15, 0.18 and 0.16 microM respectively. The pharmacological profiles of human peptides (VIP, PACAP38 and peptide histidine methionine) to stimulate frog and human VPAC(2)Rs were compared, and it was found that these peptides could only activate the frog receptor at micromolar concentrations. fVPAC(2)R was found to be widely distributed in various peripheral tissues as well as several regions of the brain. The presence of the receptor transcripts suggests the functional roles of the receptor in mediating the actions of PACAP and/or VIP in these tissues. As VIP and particularly PACAP27 are highly conserved peptides in vertebrate evolution, comparative studies of these peptides and their receptors in non-mammalian vertebrates should provide clues to better understand the physiology of these important peptides in human and other vertebrates.

Pituitary adenylate cyclase-activating polypeptide and its receptors in amphibians.

Pituitary adenylate cyclase-activating polypeptide (PACAP), a novel peptide of the secretin/glucagon/vasoactive intestinal polypeptide superfamily, has been initially characterized in mammals in 1989 and, only 2 years later, its counterpart has been isolated in amphibians. A number of studies conducted in the frog Rana ridibunda have demonstrated that PACAP is widely distributed in the central nervous system (particularly in the hypothalamus and the median eminence) and in peripheral organs including the adrenal gland. The cDNAs encoding the PACAP precursor and 3 types of PACAP receptors have been cloned in amphibians and their distribution has been determined by in situ hybridization histochemistry. Ontogenetic studies have revealed that PACAP is expressed early in the brain of tadpoles, soon after hatching. In the frog Rana ridibunda, PACAP exerts a large array of biological effects in the brain, pituitary, adrenal gland, and ovary, suggesting that, in amphibians as in mammals, PACAP may act as neurotrophic factor, a neurotransmitter and a neurohormone.

Interplay of pituitary adenylate cyclase-activating polypeptide with a silencer element to regulate the upstream promoter of the human gonadotropin-releasing hormone receptor gene.

Multiple transcription start sites were identified in the human gonadotropin releasing hormone receptor (hGnRHR) gene. Recently, an upstream promoter residing at -1727/-1674, in vicinity of a CAP site at -1673, was characterized. In this report, we elucidated the underlying mechanisms for the regulation of this promoter. Functionally, this promoter was constitutively suppressed by a silencer element (-1673/-1351) situated immediately downstream to it. On the other hand, pituitary adenylate cyclase-activating polypeptide (PACAP), via the cAMP pathway, was found to be the extracellular cue to control the upstream promoter. Following PACAP-27, PACAP-38 (30 nM) and forskolin (25 microM) treatment, there were significant increases in the reporter gene activities. By deletion analysis, the region residing at -1727 to -1577, containing the distal promoter and 97 bp of the silencer was subsequently found to be responsible for PACAP/cAMP induction. To localize the PACAP-dependent cis-acting element(s) within the silencer, block replacement scanning mutation was performed and a hGnRHR gene PACAP-responsive element (GPRE) was identified at -1676/-1648. The actions of PACAPs and forskolin on the GPRE were further evidenced by gel mobility shift assays. There was an increase in protein binding onto this element only after peptide treatment. As GnRH receptor number on gonadotrope cell surface is a key factor in regulating gonadotropin release, the present study provides an insight into the interplay between PACAP and GnRH receptors on pituitary gonadotropes to control human reproductive functions.

Incidence of diaphragmatic paralysis following supraclavicular brachial plexus block and its effect on pulmonary function.

Thirty unpremedicated ASA physical status 1-3 patients aged between 18 and 69 years, scheduled for upper limb surgery, received a conventional supraclavicular brachial plexus block using a nerve stimulator and bupivacaine 0.375% 0.5 ml.kg-1. Spirometric measurements of pulmonary function and ultrasonographic assessments of diaphragmatic function were made before the block and at 10-min intervals after injection until full motor block of the brachial plexus had developed. Complete paralysis of the ipsilateral hemidiaphragm occurred in 50% of patients. Seventeen per cent of patients had reduced diaphragmatic movement and the rest (33%) had no change in diaphragmatic movement. Those with complete paralysis all showed significant decreases in pulmonary function, whereas those with reduced or normal movement had minimal change. All patients remained asymptomatic throughout, with normal oxygen saturation on room air.

Functional mapping of a placenta-specific upstream promoter for human gonadotropin-releasing hormone receptor gene.

GnRH has been showed to regulate hCG expression and secretion from the placenta through a GnRH receptor (GnRHR)-mediated process. Recently, we have reported the isolation of human GnRHR full-length complementary DNA from the human placental cells including choriocarcinoma JEG-3 cells, immortalized extravillous trophoblasts, and primary cultures of trophoblasts. Despite these observations, the molecular mechanism that controls the transcription regulation of the GnRHR gene expression in the placenta remains unknown. Here we described the identification of an upstream placenta-specific promoter located between nucleotide (nt) -1737 and -1346 (relative to the translation start site) for the human GnRHR gene. Using transient transfection studies, this upstream promoter has been shown to determine the placental cell-specific expression of this gene. Primer extension studies further confirmed the utilization of this promoter in JEG-3 cells in vivo. By mutagenesis coupled to functional studies, we have identified four putative transcription factor-binding sites, namely human glucocorticoid receptor (hGR)-Oct-1 (nt -1718 to -1710), hGR-cAMP response element (CRE; nt -1649 to -1641), hGR-GATA (nt -1602 to -1597), and hGR-activating protein-1 (nt -1518 to -1511), that are essential to the expression of this gene. Mutations of these cis-acting motifs reduced the promoter activity. The CRE and GATA motifs were subsequently shown to be placenta specific, as mutations of these motifs caused a dramatic loss in promoter activities in the placental JEG-3 cells, but not in the ovarian carcinoma OVCAR-3, monkey kidney COS-1, and human embryonic kidney 293 cells. Gel mobility assays confirmed the binding of nuclear proteins Oct-1, CRE-binding protein, GATA-2, GATA-3, c-Fos, and c-Jun from JEG-3 cells to these four elements.

Real-time analysis of the activities of GnRH and GnRH analogs in alphaT3-1 cells by the Cytosensor microphysiometer.

Gonadotropin-releasing hormone (GnRH), acting via the GnRH receptor, elicited rapid extracellular acidification responses in mouse gonadotrope-derived alphaT3-1 cells as measured by the Cytosensor microphysiometer, which indirectly monitors cellular metabolic rates. GnRH increased the extracellular acidification rate of the cells in a dose-dependent manner (EC(50) = 1.81 +/- 0.24 nM). The GnRH-stimulated acidification rate could be attenuated by protein kinase C (PKC) down-regulation, extracellular Ca2+ depletion, and the voltage-sensitive Ca2+ channel (VSCC) blocker nifedipine, indicating that the acidification response is activated by both Ca2+ and PKC-mediated pathways. Upon continuous exposure to 100 nM GnRH or periodic stimulation by 10 nM GnRH at 40 min intervals, homologous desensitization was more pronounced in the absence of extracellular Ca2+, suggesting that desensitization of GnRH activity may be mediated via depletion of intracellular Ca2+ stores. We have also compared the potency of eight GnRH analogs on alphaT3-1 cells. No acidification response was detected for GnRH free acid, consistent with the idea that the C-terminal amide is a critical structural determinant for GnRH activity. Replacement of Gly-NH(2) at the C-terminus by N-ethylamide dramatically reduced the EC(50) value, suggesting that substitution of the Gly-NH(2) moiety by N-ethylamide increases the potency of GnRH analogs. Substitution of Gly at position 6 by D-Trp significantly reduced the EC(50) value, whereas D-Lys at the same position slightly increased the EC(50) value, implying that either an aromatic amino acid or a non-basic amino acid at position 6 may be essential for potent GnRH agonists. In summary, our results demonstrate that the Cytosensor microphysiometer can be used to evaluate the actions of GnRH and GnRH analogs in alphaT3-1 cells in a real-time and noninvasive manner. This silicon-based microphysiometric system should provide new information on the structure-function studies of GnRH and is an invaluable tool for the screening of new GnRH agonists and antagonists in the future.