PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-4 (4)
 

Clipboard (0)
None
Journals
Authors
more »
Year of Publication
Document Types
1.  Control of Cell Cycle Timing during C. elegans Embryogenesis 
Developmental biology  2008;318(1):65-72.
As a fundamental process of development, cell proliferation must be coordinated with other processes such as fate differentiation. Through statistical analysis of individual cell cycle lengths of the first eight out of ten rounds of embryonic cell division in C. elegans, we identified synchronous and invariantly ordered divisions that are tightly associated with fate differentiation. Our results suggest a three-tier model for fate control of cell cycle pace: the primary control of cell cycle pace is established by lineage and the founder cell fate, then fine-tuned by tissue and organ differentiation within each lineage, then further modified by individualization of cells as they acquire unique morphological and physiological roles in the variant body plan. We then set out to identify the pace-setting mechanisms in different fates. Our results suggest that ubiquitin-mediated degradation of CDC-25.1 is a rate-determining step for the E (gut) and P3 (muscle and germline) lineages but not others, even though CDC-25.1 and its apparent decay have been detected in all lineages. Our results demonstrate the power of C. elegans embryogenesis as a model to dissect the interaction between differentiation and proliferation, and an effective approach combining genetic and statistical analysis at single-cell resolution.
doi:10.1016/j.ydbio.2008.02.054
PMCID: PMC2442716  PMID: 18430415
statistics; single cell; fate differentiation; cdc25; Skp1-related
2.  The Children’s Hospital of Eastern Ontario Housing Checkup: A survey of the housing needs of children and youth 
Paediatrics & Child Health  2008;13(4):293-297.
BACKGROUND
Housing is a key determinant of child and youth health. A significant number of Canadian children and youth are living in housing need, but information regarding the housing status of children and youth in the Ottawa, Ontario, community is lacking.
OBJECTIVE
To examine the housing status of children and youth accessing emergency health services at the Children’s Hospital of Eastern Ontario (Ottawa, Ontario), and the factors associated with housing status.
METHODS
Youth and families of children registered at the Children’s Hospital of Eastern Ontario’s emergency department were offered a questionnaire. Affordability, adequacy, suitability and stability of housing were evaluated through self-reporting. Housing need was defined as an inability to meet one or more of these criteria. Associations among housing and household composition, demographics and weight-for-age percentiles were examined.
RESULTS
One thousand three hundred sixty surveys were completed. Fifty-four per cent of respondents (663 of 1224) were living in housing need, including 33% of respondents (381 of 1166) who were living in unaffordable housing. Single-parent families (OR 2.82), families with six or more members (OR 2.51) and families who rented (OR 5.27) were more likely to be living in housing need. Children and youth with a primary care physician were more likely to be living in stable housing (OR 0.41). Unsuitable housing was associated with extreme weight-forage percentiles (OR 1.90).
CONCLUSION
More than one-half of the children and youth in the present study were living in housing need. Health care providers have a responsibility to identify and understand the determinants of health of their patients, including housing, and to work for the improved health of their patients and their communities.
PMCID: PMC2529444  PMID: 19337595
Community medicine; Determinants of health; Housing; Public health
3.  Automated analysis of embryonic gene expression with cellular resolution in C. elegans 
Nature methods  2008;5(8):703-709.
We describe a system that permits the automated analysis of reporter gene expression in Caenorhabditis elegans with cellular resolution continuously during embryogenesis and demonstrate its utility by defining the expression patterns of reporters for several embryonically expressed transcription factors. The invariant cell lineage permits the automated alignment of multiple expression profiles, allowing the direct comparison of the expression of different genes' reporters. We have also used the system to monitor perturbations to normal development involving changes both in cell division timing and in cell fate. Systematic application could reveal the gene activity of each cell throughout development.
doi:10.1038/nmeth.1228
PMCID: PMC2553703  PMID: 18587405
4.  Maternal undernutrition and the ovine acute phase response to vaccination 
Background
The acute phase response is the immediate host response to infection, inflammation and trauma and can be monitored by measuring the acute phase proteins (APP) such as haptoglobin (Hp) or serum amyloid A (SAA). The plane of nutrition during pregnancy is known to affect many mechanisms including the neuroendocrine and neuroimmune systems in neonatal animals but effects on the APP are unknown. To investigate this phenomenon the serum concentration of Hp and SAA was initially determined in non-stimulated lambs from 3 groups (n = 10/group). The dams of the lambs of the respective groups were fed 100% of requirements throughout gestation (High/High; HH); 100% of requirements for the first 65 d of gestation followed by 70% of requirements until 125 d from when they were fed 100% of requirements (High/Low; HL); 65% of liveweight maintenance requirements for the first 65 d gestation followed by 100% of requirements for the remainder of pregnancy (Low/High; LH). The dynamic APP response in the lambs was estimated by measuring the concentration of Hp and SAA following routine vaccination with a multivalent clostridial vaccine with a Pasteurella component, Heptavac P™ following primary and secondary vaccination.
Results
The Hp and SAA concentrations were significantly lower at the time of vaccination (day 8–14) than on the day of birth. Vaccination stimulated the acute phase response in lambs with increases found in both Hp and SAA. Maternal undernutrition led to the SAA response to vaccination being significantly lower in the HL group than in the HH group. The LH group did not differ significantly from either the HH or HL groups. No significant effects of maternal undernutrition were found on the Hp concentrations. A significant reduction was found in all groups in the response of SAA following the second vaccination compared to the response after the primary vaccination but no change occurred in the Hp response.
Conclusion
Decreased SAA concentrations, post-vaccination, in lambs born to ewes on the HL diet shows that maternal undernutrition prior to parturition affects the innate immune system of the offspring. The differences in response of Hp and SAA to primary and secondary vaccinations indicate that the cytokine driven APP response mechanisms vary with individual APP.
doi:10.1186/1746-6148-4-1
PMCID: PMC2233616  PMID: 18197966

Results 1-4 (4)