Search

Your search keyword '"Menaker, Rena J."' showing total 8 results
Start Over Author "Menaker, Rena J."
8 results on '"Menaker, Rena J."'

6. Helicobacter pylori induces apoptosis of macrophages in association with alterations in the mitochondrial pathway.

Author

Menaker, Rena J, Ceponis, Peter J M, and Jones, Nicola L

Abstract

Helicobacter pylori is a gastric bacterial pathogen that evades host immune responses in vivo and is associated with the development of gastritis, peptic ulcer disease, and gastric cancers. Induction of macrophage apoptosis is a method employed by multiple pathogens to escape host immune responses. Therefore, we hypothesized that H. pylori induces apoptosis of infected macrophages. RAW 264.7 cells were infected with H. pylori strain 60190, and apoptosis was assessed. Transmission electron microscopy and fluorescence microscopy showed that infected macrophages displayed morphological features characteristic of apoptosis. Quantification by acridine orange-ethidium bromide fluorescent-dye staining showed that apoptosis was dose and time dependent, and apoptosis was further confirmed by increased binding of annexin V-fluorescein isothiocyanate (FITC) to externalized phosphatidylserine of infected but not of control macrophages. Macrophages infected with isogenic mutants of H. pylori strain 60190 deficient in either cagA or vacA induced significantly less apoptosis than the parental strain, as assessed by increased binding of annexin V-FITC. Western blot analysis of whole-cell protein lysates revealed that infection with strain 60190 induced a time-dependent increase in cleavage of procaspase 8 and disappearance of full-length Bid compared with uninfected cells. Furthermore, pharmacological inhibition of caspase 8 caused a decrease in levels of apoptosis. Finally, infection caused a time-dependent increase in mitochondrial-membrane permeability and release of cytochrome c into the cytosol. These results suggest that H. pylori induces apoptosis of macrophages in association with alterations in the mitochondrial pathway. Elimination of this key immunomodulatory cell may represent a mechanism employed by the bacterium to evade host immune responses.

Published
2004

7. Waiting for children's surgery in Canada: the Canadian Paediatric Surgical Wait Times project.

Author

Wright JG, Menaker RJ, Canadian Paediatric Surgical Wait Times Study Group, Wright, James G, and Menaker, Rena J

Abstract

Background: In addition to possibly prolonged suffering and anxiety, extended waits for children's surgery beyond critical developmental periods has potential for lifelong impact. The goal of this study was to determine the duration of waits for surgery for children and youth at Canadian paediatric academic health sciences centres using clinically-derived access targets (i.e., the maximum acceptable waiting periods for completion of specific types of surgery) as used in this Canadian Paediatric Surgical Wait Times project.Methods: We prospectively applied standardized wait-time targets for surgery, created by nominal-group consensus expert panels, to pediatric patients at children's health sciences centres across Canada with decision-to-treat dates of Sept. 1, 2007 or later. From Jan. 1 to Dec. 30, 2009, patients' actual wait times were compared with their target wait times to determine the percentage of patients receiving surgery after the target waiting period.Results: Overall, 27% of pediatric patients from across Canada (17,411 of 64,012) received their surgery after their standardized target waiting period. Dentistry, ophthalmology, plastic surgery and cancer surgery showed the highest percentages of surgeries completed past target.Interpretation: Many children wait too long for surgery in Canada. Specific attention is required, in particular, in dentistry, ophthalmology, plastic surgery and cancer care, to address children's wait times for surgery. Improved access may be realized with use of national wait-time targets. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

8. Pediatric surgical capacity and demand: analysis reveals a modest gap in capacity and additional efficiency opportunities.

Author

Fixler T, Menaker RJ, Blair GK, and Wright JG

Subjects
Canada, Hospitals, Pediatric, Humans, Efficiency, Organizational, Health Services Accessibility, Health Services Needs and Demand, Surgery Department, Hospital organization & administration, Surgery Department, Hospital statistics & numerical data
Abstract

The Canadian Paediatric Surgical Wait Times Project conducted an analysis of the alignment between capacity (supply) and demand for pediatric surgery at nine participating hospitals in five provinces. Demand for surgery was modelled using wait list data by assigning patients into monthly buckets of demand ("demand windows") based on the date on which a decision was made to proceed with their surgery plus their surgical wait time access target. Demand was then related to available capacity for various key resources (e.g., operating room availability, intensive care unit [ICU] and in-patient beds). The results indicate a small and not insurmountable gap of 8.5-11% in pediatric surgical capacity at these hospitals. A further capacity issue at many hospitals was ICU occupancy. In addition, an examination of several key performance indicators related to the management of peri-operative resources indicated that opportunities exist for deploying existing resources more efficiently, such as increasing on-time starts and reducing cancellation rates for elective surgery.

Published
2011
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results