Hospital for Sick Children

About: Hospital for Sick Children is a healthcare organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Population & Medicine. The organization has 4097 authors who have published 3746 publications receiving 129066 citations. The organization is also known as: Sick Kids Hospital & SickKids.

Evidence for the serotonin HTR2A receptor gene as a susceptibility factor in attention deficit hyperactivity disorder (ADHD)

Abstract: A recent study demonstrated that treatment of hyperactive mice with psychostimulants and serotonergic agents produced a calming effect that was dependent on serotonergic neurotransmission and was not associated with any changes in extracellular dopamine levels.1 The complex interaction between the serotonergic and dopaminergic neurotransmitter systems suggests that a balance between the two systems may be necessary for mediating hyperactive behaviour. Defects in serotonin system genes, therefore, may disrupt normal brain serotonin function causing an imbalance between these neurotransmitter systems leading to the development of attention deficit hyperactivity disorder (ADHD). Using the transmission disequilibrium test (TDT), the current study assesses for linkage disequilibrium between polymorphisms in the serotonin HTR2A receptor gene and ADHD. One hundred and fifteen families with a total of 143 children diagnosed with ADHD (DSM-IV) were genotyped for the His452Tyr and the T102C polymorphisms in the serotonin HTR2A receptor gene. TDT analysis revealed a preferential transmission of the 452Tyr allele to the affected offspring (P = 0.03), suggesting linkage disequilibrium of this polymorphism with ADHD. This may open a new door in ADHD molecular genetics research, expanding the existing view of a catecholaminergic hypothesis to include a serotonergic hypothesis and should help elucidate the complex interplay among the neurotransmitter systems in the etiology of ADHD.

A large scale hearing loss screen reveals an extensive unexplored genetic landscape for auditory dysfunction.

Abstract: The developmental and physiological complexity of the auditory system is likely reflected in the underlying set of genes involved in auditory function. In humans, over 150 non-syndromic loci have been identified, and there are more than 400 human genetic syndromes with a hearing loss component. Over 100 non-syndromic hearing loss genes have been identified in mouse and human, but we remain ignorant of the full extent of the genetic landscape involved in auditory dysfunction. As part of the International Mouse Phenotyping Consortium, we undertook a hearing loss screen in a cohort of 3006 mouse knockout strains. In total, we identify 67 candidate hearing loss genes. We detect known hearing loss genes, but the vast majority, 52, of the candidate genes were novel. Our analysis reveals a large and unexplored genetic landscape involved with auditory function.The full extent of the genetic basis for hearing impairment is unknown. Here, as part of the International Mouse Phenotyping Consortium, the authors perform a hearing loss screen in 3006 mouse knockout strains and identify 52 new candidate genes for genetic hearing loss.

Lead Contamination around Secondary Smelters: Estimation of Dispersal and Accumulation by Humans

Abstract: A high rate of lead fallout around two secondary lead smelters originated mainly from episodal large-particulate emissions from low-level fugitive sources rather than from stack fumes. The lead content of dustfall, and consequently of soil, vegetation, and outdoor dust, decreased exponentially with distance from the two smelters. Between 13 and 30 percent of the children living in the contaminated areas had absorbed excessive amounts of lead (more than 40 micrograms per 100 milliliters of blood and more than 100 micrograms per gram of hair) as compared with less than 1 percent in a control group. A relationship between blood and hair was established which indicated that the absorption was fairly constant for most children examined. It seemned that the ingestion of contaminated dirt and dusts rather than "paint pica" was the major route of lead intake. Metabolic changes were found in most of 21 children selected from those with excessive lead absorption; 10 to 15 percent of this group showed subtle neurological dysfunctions and minor psychomotor abnormalities.

High tidal volume ventilation causes different inflammatory responses in newborn versus adult lung.

Abstract: We investigated the effect of high VT ventilation on adult and newborn rats by examining pulmonary injury and cytokine messenger RNA (mRNA). On the basis of compliance, edema formation, and histology, ventilation with 25 ml·kg−1 was more injurious to adult rats than newborns. Ventilation with 40 ml kg−1 minimally affected compliance in newborns but caused death in adults. Ventilation of adults for 30 minutes at 25 ml kg−1 upregulated the mRNA expression of interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), macrophage inflammatory protein-2 (MIP-2), and IL-10, whereas in newborns such ventilation only increased mRNA expression of MIP-2 and IL-10. When VT was raised to 40 ml kg−1 in newborns, IL-1β mRNA levels were additionally increased at 30 minutes, whereas ventilation for 3 hours additionally increased IL-6 and TNF-α mRNA. In newborns, the addition of 100% oxygen (O2) to 30 minutes of ventilation blunted the high VT induction of IL-1β, IL-10, and MIP-2 mRNA expressions, whereas at 3 hours, 100%...

Dysarthria of adult cerebral palsy: I. Intelligibility and articulatory impairment.

Abstract: The articulation errors of 32 spastic and 18 athetoid males, aged 17–55 years, were analyzed using a confusion matrix paradigm. The subjects had a diagnosis of congenital cerebral palsy, and adequa...