How active are children in Toronto? A comparison with accelerometry data from the Canadian Health Measures Survey.

INTRODUCTION: The Canadian Health Measures Survey (CHMS) is the most comprehensive direct health measures survey ever conducted in Canada. Results show that the majority of children and youth (93%) do not meet current physical activity recommendations for health. CHMS data have not yet been considered alongside an independent sample of Canadian youth; such a Canadian-context examination could support CHMS results and contribute to discussions regarding accelerometry data reduction protocols. METHODS: From 2010 to 2011, valid accelerometry data were collected on 856 children living in the Greater Toronto Area (GTA). Where possible, data presentation and analyses were aligned with the CHMS protocol such that physical activity outcomes could be compared. RESULTS: Overall, trends were similar, with some deviations likely due to contextual and sampling differences and differences in data collection/reduction protocols regarding accelerometer model selection, wear time, activity intensity thresholds and epoch. CONCLUSION: The similar trends support the notion that physical inactivity is an ongoing problem in communities across Canada.

A rational vaccine pipeline for tuberculosis.

The development of tuberculosis (TB) vaccines is at a turning point, with the promise of new vaccines on the horizon. Over the next few years, it is possible that we will see a phase III multi-site clinical trial of at least one new TB vaccine and perhaps the introduction of a TB vaccine by the end of the decade. However, many gaps remain in our understanding of TB pathogenesis as well as the host immune responses required to provide protective immunity. A major challenge for TB vaccines is to establish a correlate of vaccine immunity which would greatly facilitate bridging studies needed to approve, license and distribute new TB vaccines in all areas endemic for TB. This will require TB vaccines that are both safe and effective in all populations. It cannot be accomplished without hard work as well as additional resources that match the ambitious goals of the TB community.

Fluorescence in situ hybridization for identification of Tritrichomonas foetus in formalin-fixed and paraffin-embedded histological specimens of intestinal trichomoniasis.

In the present study a highly species-specific oligonucleotide sequence of Tritrichomonas foetus 18S rRNA was used to design an antisense probe for identification of T. foetus in formalin-fixed and paraffin-embedded histological specimens by means of fluorescence in situ hybridization (FISH). Using archival histological specimens from several species with light microscopic evidence of intestinal trichomoniasis, and under optimized hybridization conditions, the probe positively identified trichomonads in colonic specimens from piglets and a kitten with PCR-confirmed T. foetus infection. Neither positive hybridization of the probe or PCR amplification of T. foetus DNA was observed in histological specimens from hamster (Tritrichomonas muris), turkey, nor mouse (Entamoeba muris) intestinal protozoal infections. Sequence-specific binding of the probe was further verified by successfully out-competing the hybridization with 10 x molar excess unlabeled probe and failure of a labeled sense probe to hybridize. The FISH assay described here enables simultaneous location and molecular identification of T. foetus in formalin-fixed and paraffin-embedded histological specimens of intestinal trichomoniasis. The methods employed are likely to also be applicable to probes designed for specific recognition of other trichomonad species, especially in mammalian tissue where red blood cell auto-fluorescence can be easily differentiated from the hybridization signal of trichomonads.

Feline diarrhoea associated with Tritrichomonas cf. foetus and Giardia co-infection in an Australian cattery.

A 10-week-old female Ocicat was presented at a primary care feline veterinary practice for failure to thrive and diarrhoea. Numerous trophozoites, atypical for Giardia sp., were detected on a direct faecal examination, in addition to Giardia cysts. Although the failure to thrive and diarrhoea resolved following treatment for giardiasis, further diagnostic tests performed on faecal specimens from the kitten and 15 other Ocicats from the same cattery, including culture of trophozoites in In Pouch medium, PCR testing and molecular sequencing of PCR amplicons, confirmed infection with Tritrichomonas cf. foetus. This is the first report in Australia of feline trichomoniasis, which appears to be an emerging infectious disease of cats. Pertinent information regarding the clinical features, diagnosis, therapy, and potential source of feline trichomoniasis within Australia are discussed.

Ca(2+) entry activated by S-nitrosylation. Relationship to store-operated ca(2+) entry.

The coupling between Ca(2+) pools and store-operated Ca(2+) entry channels (SOCs) remains an unresolved question. Recently, we revealed that Ca(2+) entry could be activated in response to S-nitrosylation and that this process was stimulated by Ca(2+) pool emptying (Favre, C. J., Ufret-Vincenty, C. A., Stone, M. R., Ma, H-T. , and Gill, D. L. (1998) J. Biol. Chem. 273, 30855-30858). In DDT(1)MF-2 smooth muscle cells and DC-3F fibroblasts, Ca(2+) entry activated by the lipophilic NO donor, GEA3162 (5-amino-3-(3, 4-dichlorophenyl)1,2,3,4-oxatriazolium), or the alkylator, N-ethylmaleimide, was observed to be strongly activated by transient external Ca(2+) removal, closely resembling activation of SOC activity in the same cells. The nonadditivity of SOC and NO donor-activated Ca(2+) entry suggested a single entry mechanism. Calyculin A-induced reorganization of the actin cytoskeleton prevented SOC but had no effect on GEA3162-induced Ca(2+) entry. However, a single entry mechanism could account for both SOC and NO donor-activated entry if the latter reflected direct modification of the entry channel by S-nitrosylation, bypassing the normal coupling process between channels and pools. Small differences between SOC and GEA3162-activated Ba(2+) entry and sensitivity to blockade by La(3+) were observed, and in HEK293 cells SOC activity was observed without a response to thiol modification. It is concluded that in some cells, S-nitrosylation modifies an entry mechanism closely related to SOC and/or part of the regulatory machinery for SOC-mediated Ca(2+) entry.

Ca2+ pool emptying stimulates Ca2+ entry activated by S-nitrosylation.

The entry of Ca2+ following Ca2+ pool release is a major component of Ca2+ signals; yet despite intense study, how "store-operated" entry channels are activated is unresolved. Because S-nitrosylation has become recognized as an important regulatory modification of several key channel proteins, its role in Ca2+ entry was investigated. A novel class of lipophilic NO donors activated Ca2+ entry independent of the well defined NO target, guanylate cyclase. Strikingly similar entry of Ca2+ induced by cell permeant alkylators indicated that this Ca2+ entry process was activated through thiol modification. Significantly, Ca2+ entry activated by either NO donors or alkylators was highly stimulated by Ca2+ pool depletion, which increased both the rate of Ca2+ release and the sensitivity to thiol modifiers. The results indicate that S-nitrosylation underlies activation of an important store-operated Ca2+ entry mechanism.

Evidence for the involvement of histamine in the antidystonic effects of diphenhydramine.

Although diphenhydramine hydrochloride is known to eliminate or reduce the symptoms of dystonia in human patients with acute dystonic reactions and idiopathic torsion dystonia, its mechanism of action is still unclear. In the present study, we show that the antihistamine properties of diphenhydramine may contribute to its beneficial effects. Acute dystonic reactions were produced in rats with unilateral microinjection of haloperidol into the red nucleus as previously described. Similar to the pattern in humans, this effect could be attenuated by coadministration of diphenhydramine. Unilateral microinjection of histamine itself into the rat red nucleus produced dystonic postures (torticollis) in a dose-dependent manner, demonstrating that a histamine dysfunction could contribute to the pathophysiology of dystonia. The torticollis produced by histamine could be significantly attenuated with coadministration of the H1 antagonists diphenhydramine or pyrilamine or the H2 antagonist cimetidine. These effects are thought to be mediated through the red nucleus because significantly more torticollis was observed when histamine was injected into the red nucleus rather than surrounding mid-brain areas, the substantia nigra, or the lateral ventricle. The present data, taken together with studies in humans, suggest the involvement of histamine in some types of dystonia. Furthermore, the red nucleus and related motor pathways may have a more important role in dystonia than previously thought.

Monoclonal antibodies as reversible equilibrium carriers of radiopharmaceuticals.

We have prepared monoclonal antibodies (MoAbs) with the specific ability to bind metal chelates such as 111In benzyl EDTA. One, 10, 50 and 100 micrograms MoAb CHA255 Kb = 4 X 10E9 was complexed with 111In BLEDTA II, BLEDTA IV, and benzyl EDTA and injected i.v. in Balb/c mice with KHJJ tumor. The biological half-life by whole body counting was profoundly altered for all three compounds; from minutes to hours with 10 micrograms; to days with 100 micrograms. Tumor uptake increased 50 fold at 24 h with increasing MoAb but satisfactory tumor concentrations (3% per g) and tumor/blood ratios (1.8:1) were obtained with an amount equivalent to 7 mg for a human. Blood level and whole body activity were decreased 30-50% within 3 h or i.v. injection of a "flushing" dose of unlabeled indium benzyl EDTA, increasing tumor/blood ratios to 50:1.

Antibodies against metal chelates.

Because monoclonal antibodies can recognize and bind to specific groups of atoms such as tumour antigens, they have promise for use in vivo as carriers of radionuclides, drugs or other appended molecules for diagnosis and treatment of disease. Attachment of metal ions to antibodies by means of bifunctional chelating agents can add the diverse nuclear, physical and chemical properties of the metallic elements to these specific binding proteins (ref. 4 and refs therein). With the ultimate aim of engineering probe-binding properties into the antibodies themselves, we have now prepared monoclonal antibodies against the EDTA chelate of indium. These antibodies show a remarkable preference for indium chelates; changing to another metal such as scandium or gallium can decrease the antibody-binding constant by more than three orders of magnitude. These antibodies also introduce a new degree of control over the biological distributions of chelated radionuclides, markedly altering their uptake in tumours and normal organs.

Role of variable region gene expression and environmental selection in determining the antiphosphorylcholine B cell repertoire.

To evaluate the role of environmental selective processes, as opposed to variable region gene expression, in the determination of B cell repertoire expression, we have assessed the phosphorylcholine (PC)-specific repertoire of precursor cells that remain in bone marrow cell populations after the removal of surface immunoglobulin (sIg)-bearing cells. Such cells are assumed to represent a stage in B cell maturation before the expression of sIg, and thus at a time when they have not as yet interfaced with environmental influences that operate through sIg receptors such as antigenic stimulation, tolerance, or antiidiotypic regulation. The repertoire as expressed in these cells, therefore, should reflect the readout of immunoglobulin variable region genes as they are expressed in progenitors to B cells. The results of these studies indicate that, as in mature primary B cell pools of BALB/c mice, the majority of PC-responsive sIg- bone marrow cells are of the T15 clonotype. Thus, environmental selective mechanisms would not appear to be required for the high frequency of B cells of the T15 idiotype in the primary B cell repertoire of BALB/c mice. Analysis of the sIg- bone marrow cells in (CBA/N X BALB/c)F1 male mice demonstrated that the deficit of PC-responsive mature B cells, which is a characteristic of this murine strain, must occur after receptor expression, since a normal frequency of PC-responsive and T15-expressing cells is present in their sIg- bone marrow population. Finally, these same mice were used to obtain bone marrow cell preparations from individual leg bones, so as to permit an analysis of the occurrence of T15+ and T15- clonotypes within individual bone marrow populations. The findings from these studies indicate that T15+ B cells occur as a high frequency event within bone marrow generative cell pools. Furthermore, bone marrow populations that are positive for PC-responsive precursor cells often display multiple copies of such precursor cells that are exclusively either T15+ or T15-. This finding indicates that clonal expansion of cells within the B cell lineage apparently occurs before immunoglobulin receptor acquisition.