Safety and feasibility of day case patent foramen ovale (PFO) closure facilitated by intracardiac echocardiography.

Ultrasound guided patent foramen ovale (PFO) closure has traditionally utilized transoesophageal echocardiography (TOE) under general anaesthesia. Some centres use fluoroscopic guidance alone to facilitate day case PFO closure. Intracardiac echocardiography (ICE) is performed via femoral vein access using an 11 Fr sheath providing accurate guidance without the necessity for general anaesthesia.

Prevalence of HIV and hepatitis C virus infections among inmates of Ontario remand facilities.

Background: Each year more than 56 000 adult and young offenders are admitted to Ontario's remand facilities (jails, detention centres and youth centres). The prevalence of HIV infection in Ontario remand facilities was last measured over a decade ago, and no research on the prevalence of hepatitis C virus (HCV) infection has been conducted in such facilities. We sought to determine the prevalence of HIV infection, HCV infection and HIV-HCV coinfection among inmates in Ontario's remand facilities.

Genetic variation in hepatic glucose-6-phosphatase system genes in cases of sudden infant death syndrome.

Genetic deficiencies of the hepatic glucose-6-phosphatase system, either of the enzyme (G6PC1) or of the glucose-6-phosphate transporter (G6PT1), result in fasting hypoglycaemia. Low hepatic G6PC1 activities were previously reported in a few term sudden infant death syndrome (SIDS) infants and assumed to be due to G6PC1 genetic deficiencies. In preterm infants, failures of postnatal activation of G6PC1 expression suggest disordered development as a novel cause of decreased G6PC1 activity in SIDS.

Chapter 6: Epidemiology and transmission dynamics of genital HPV infection.

This chapter provides an overview of the epidemiology of human papillomavirus (HPV) infection, with a focus on the dynamics of sexual transmission. We explore concepts related to the spread of sexually transmitted infections, including population prevalence, duration of infectivity, patterns of sexual contacts, and transmissibility, including modifiers of susceptibility and infectivity. HPV prevalence and incidence are high in most studies, particularly amongst young women.

Glucose production in the human placenta.

Glucose transfer from mother to fetus by placental facilitated diffusion is the dominant mechanism by which the fetus acquires glucose. In small for gestational age pregnancies, fetal glucose concentrations tend to be lower than normal and this persists following delivery. GLUT1 is the major glucose transporter in human placenta but there is no evidence of GLUT1 deficiency as a cause of the lower fetal glucose concentration in small for gestational age pregnancy.

Modeling the sexual transmissibility of human papillomavirus infection using stochastic computer simulation and empirical data from a cohort study of young women in Montreal, Canada.

The authors estimated plausible ranges of the probability of human papillomavirus (HPV) transmission per coital act among newly forming couples by using stochastic computer simulation. Comparative empirical data were obtained in 1996-2001 from a cohort study of female university students in Montreal, Canada. Female prevalence and frequency of sexual intercourse and condom use were set equal to those in the cohort.

Psychosocial impact of repeat HIV-negative testing: a follow-up study.

Continued sexual risk behavior following repeatedly testing HIV-negative in the Polaris HIV Seroconversion Study (Ontario, Canada) led to this follow-up study which identifies the impact of repeat negative testing among 64 men and women. Repeat HIV-negative testing frequently results in confusion as to what constitutes risk and occasionally to thoughts of HIV immunity. Narrative accounts include beliefs that monogamy constitutes safety from HIV, that psychosocial factors other than repeatedly testing negative leads to risk, and that sexual risk reduction is unsustainable.

Preparation of intact microsomes from cultured mammalian H4IIE cells.

Introduction: Mammalian cell culture is widely used for the cloning and expression of insoluble proteins. The established methods of sub-cellular fractionation of tissues are not always directly suitable for the sub-cellular fractionation of cultured cells. In this study we have optimized the conditions for the preparation of microsomal fractions from cultured cells with the aim of isolating intact vesicles that are suitable for the assay of transport proteins and lumenal enzymes.

Identification of novel polymorphisms in the glucokinase and glucose-6-phosphatase genes in infants who died suddenly and unexpectedly.

Sudden and unexpected infant deaths can be unexplained [sudden infant death syndrome (SIDS)] or explained (non-SIDS) but risk factors including lower birthweight are similar in both groups. Mutations in the glucokinase (GK) gene result in Maturity Onset Diabetes of the Young type 2 (MODY 2) and are associated with lower birthweight. Low hepatic glucose-6-phosphatase (G6PC1) expression occurs in both low birthweight and SIDS infants.

Immunodetection of the expression of microsomal proteins encoded by the glucose 6-phosphate transporter gene.

Glucose 6-phosphate transport has been well characterized in liver microsomes. The transport is required for the functioning of the glucose-6-phosphatase enzyme that is situated in the lumen of the hepatic endoplasmic reticulum. The genetic deficiency of the glucose 6-phosphate transport activity causes a severe metabolic disease termed type 1b glycogen storage disease.

Glucose homeostasis in the newborn.

Hepatic glucose production by glycogenolysis and gluconeogenesis is essential to maintain blood glucose levels, and the glucose-6-phosphatase system catalyses the terminal step of both pathways. Developmental delays in the postnatal up-regulation of hepatic glucose-6-phosphatase enzyme activity are common in preterm infants. Two groups of infants have been identified with failure of developmental regulation of glucose homeostasis.

Plasma catecholamines and the counterregulatory responses to hypoglycemia in infants: a critical role for epinephrine and cortisol.

The purpose of this study was to define plasma catecholamine responses as part of the counterregulatory hormonal reaction to hypoglycemia in infants after a regular 3- to 4-h feed was omitted. Hormone levels were assessed once, at the end of the fast or at hypoglycemia. The 121 infants were subdivided into three groups for analysis: normoglycemia (n = 94, 78%); transient hypoglycemia (n = 11, 9%); or severe and persistent hypoglycemia (n = 16, 13%).

Thyroid hormone potentiates glucocorticoid-evoked airway Na+ transport without affecting alpha-ENaC transcription.

Glucocorticoid and thyroid hormones (T3) are important for the development of the lungs' Na+ absorbing phenotype, which is essential for the integrated functioning of the respiratory tract. Electrometric studies of H441 airway epithelial cells confirmed that dexamethasone increases apical Na+ conductance (GNa) and demonstrated that T3 facilitates this control over GNa. Assays of transcriptional activity showed that dexamethasone caused concentration-dependent activation of the human alpha-ENaC promoter (EC50 approximately 5 nM) but, despite its clear effect on GNa, T2 had no effect upon the transcriptional response to dexamethasone.

Symptomatic primary HIV infection or risk experiences? Circumstances surrounding HIV testing and diagnosis among recent seroconverters.

Our objective was to understand the circumstances surrounding HIV testing among recent HIV seroconverters (n=80) compared to HIV-negative controls (n=106) in Ontario, Canada using self-reported interview data. Diagnosis of symptomatic primary HIV infection (SPHI) was defined as diagnosis by the participant's physician. Testing in response to symptoms was reported by 42% of seroconverters vs 12% of controls.

Identification and characterisation of a new human glucose-6-phosphatase isoform.

The liver endoplasmic reticulum glucose-6-phosphatase catalytic subunit (G6PC1) catalyses glucose 6-phosphate hydrolysis during gluconeogenesis and glycogenolysis. The highest glucose-6-phosphatase activities are found in the liver and the kidney; there have been many reports of glucose 6-phosphate hydrolysis in other tissues. We cloned a new G6Pase isoform (G6PC3) from human brain encoded by a six-exon gene (chromosome 17q21).

Prior opiate injection and incarceration history predict injection drug use among inmates.

Aims: To describe injection drug use among inmates, and to identify correlates of drug injection while incarcerated.

Design: Cross-sectional survey.

Setting: Six provincial correctional centres in Ontario, Canada.

Voluntary HIV testing among inmates: sociodemographic, behavioral risk, and attitudinal correlates.

We sought to determine the prevalence and correlates of self-reported HIV testing among inmates in correctional centers in Ontario, Canada. A cross-sectional survey was conducted with a stratified random sample of 597 male and female adult inmates. The participation rate was 89%.

Delayed application of condoms is a risk factor for human immunodeficiency virus infection among homosexual and bisexual men.

The objective of this analysis was to identify risk factors for recent human immunodeficiency virus (HIV) infection among homosexual and bisexual men in Ontario, Canada, during 1998-2001. Participants were recruited through the provincial HIV diagnostic laboratory and through physicians and community organizations. HIV test results were used to identify recent seroconverters (cases).

Developmental disorders of glucose metabolism in infants.

Background: Developmental failures to adequately control postnatal blood glucose levels are common in the transition from fetal to infant life and can persist for many months. The standard method of functionally measuring hepatic glucose production and/or disordered glucose production is the response to a glucagon tolerance test.

Method: We adapted the standard glucagon tolerance test used for children and adults for use in preterm infants.

Polymorphisms in genes involved in glucose metabolism in cases of sudden infant death syndrome.

Background: Infants with intra-uterine growth retardation have an increased risk of Sudden Infant Death Syndrome (SIDS). Hypoglycaemia is also significantly correlated with retardation of intra-uterine growth. A number of mutations in key proteins involved in regulation of blood glucose (e.

An inadequate glycaemic response to glucagon is linked to insulin resistance in preterm infants?

Aims: To define clinical, metabolic, and hormonal characteristics of preterm infants relative to glucagon responsiveness.

Methods: Two phase study of 78 preterm infants (25-36 weeks gestation) on regular four hourly feeds anticipating discharge home at 36 weeks mean corrected gestation. In phase 1 infants were fasted until hypoglycaemic, or maximally for eight hours.

Rat liver glucose-6-phosphatase system: light scattering and chemical characterization.

Glucose-6-phosphatase is a multicomponent system located in the endoplasmic reticulum, involving both a catalytic subunit (G6PC) and several substrate and product carriers. The glucose-6-phosphate carrier is called G6PT1. Using light scattering, we determined K(D) values for phosphate and glucose transport in rat liver microsomes (45 and 33mM, respectively), G6PT1 K(D) being too low to be estimated by this technique.

Increases in HIV incidence among men who have sex with men undergoing repeat diagnostic HIV testing in Ontario, Canada.

Objective: To estimate HIV incidence density for different exposure categories among people undergoing repeat testing in Ontario, Canada.

Methods: Persons using voluntary, diagnostic HIV testing at least twice were identified by computerized and manual record linkage. In the 1992-2000 period, 980 seroconverters and 340 994 repeat negative testers contributed 936 145 person years (PY) of observation.

Histone 2A stimulates glucose-6-phosphatase activity by permeabilization of liver microsomes.

Histone 2A increases glucose-6-phosphatase activity in liver microsomes. The effect has been attributed either to the conformational change of the enzyme, or to the permeabilization of microsomal membrane that allows the free access of substrate to the intraluminal glucose-6-phosphatase catalytic site. The aim of the present study was the critical reinvestigation of the mechanism of action of histone 2A.