Assessment of Effectiveness of Control Strategies Against Simulated Outbreaks of Highly Pathogenic Avian Influenza in Ontario,Canada

The North American Animal Disease Spread Model (NAADSM) is a stochastic model framework developed to simulate the spread of highly contagious diseases of livestock and poultry, such as foot‐and‐mouth disease and highly pathogenic avian influenza (HPAI). The objective of this study was to make recommendations on the most effective HPAI control policy for Canada, specifically, on the effect of different speeds of detection, effectiveness of movement restrictions and stamping‐out and ring‐culling strategies on the magnitude of an HPAI outbreak. In addition, the effect of introduction of infection in a range of multiple farms simultaneously was also evaluated. A total of 21 060 scenarios, defined as different combinations of parameters for various epidemiological conditions and control measures, were created to simulate the number of poultry flocks that would become infected as a result of an incursion of HPAI. Each scenario was parameterized in NAADSM and replicated 1000 times, generating the median number of flocks infected at the end of the simulated outbreak for each scenario. Negative binomial regression analysis was used to model significant explanatory variables of the median number of flocks infected at the end of each simulated outbreak for each of the 21 060 scenarios. The final model included the following explanatory variables: number and type initially infected flock(s), density of flocks within the county where the initially infected flock(s) was located, probability of transmission through indirect contact, subclinical spread of the infection, speed of detection and a two‐way interaction between intensity of bird destruction strategy and movement restriction effectiveness to reduce transmission through direct and indirect contacts. The modelling results suggested that stamping out of the detected infected flocks, without ring culling, in combination with effective movement restrictions on direct and indirect contacts, would be the most appropriate policy for Ontario.     

IMPaCT Back study protocol. Implementation of subgrouping for targeted treatment systems for low back pain patients in primary care: a prospective population-based sequential comparison

Background  

Prognostic assessment tools to identify subgroups of patients at risk of persistent low back pain who may benefit from targeted treatments have been developed and validated in primary care. The IMPaCT Back study is investigating the effects of introducing and supporting a subgrouping for targeted treatment system in primary care.     

The Halifax explosion and the birth of a surgical specialty—myth or reality

The work of Dr William E. Ladd after a devastating explosion in Halifax in 1917 has been credited with his decision to devote his subsequent career to the betterment of surgical care for children. He has been recognized as the “father of pediatric surgery” in North America. The authors present a written refutation of this causal association by Dr Ladd.     

Cloning and characterization of voltage‐gated calcium channel alpha1 subunits in Xenopus laevis during development

Voltage‐gated calcium channels play a critical role in regulating the Ca²⁺ activity that mediates many aspects of neural development, including neural induction, neurotransmitter phenotype specification, and neurite outgrowth. Using Xenopus laevis embryos, we describe the spatial and temporal expression patterns during development of the 10 pore‐forming alpha1 subunits that define the channels' kinetic properties. In situ hybridization indicates that Ca_V1.2, Ca_V2.1, Ca_V2.2, and Ca_V3.2 are expressed during neurula stages throughout the neural tube. These, along with Ca_V1.3 and Ca_V2.3, beginning at early tail bud stages, and Ca_V3.1 at late tail bud stages, are detected in complex patterns within the brain and spinal cord through swimming tadpole stages. Additional expression of various alpha1 subunits was observed in the cranial ganglia, retina, olfactory epithelium, pineal gland, and heart. The unique expression patterns for the different alpha1 subunits suggests they are under precise spatial and temporal regulation and are serving specific functions during embryonic development. Developmental Dynamics 238:2891–2902, 2009. © 2009 Wiley‐Liss, Inc.     

Autologous tissue immediate breast reconstruction: desired but oncologically safe?

Background: There has been a dramatic increase in the incidence of immediate breast reconstruction after mastectomy for breast cancer over the past few decades and autologous tissue flaps are being used with increasing frequency. Concern has been expressed that these complex procedures may lead to a delay in the delivery of adjuvant therapy, which in turn may adversely affect recurrence and survival rates. Several publications have looked into the effect of immediate reconstruction on the timing of delivery of adjuvant therapy, but all types of immediate breast reconstruction (IBR) tend to be examined as a homogenous group. Aim: The aim of this review was to search current literature and look specifically at the effect of autologous tissue reconstructions on adjuvant therapy, and identify possible causes of delay. Discussion: From the data analysed, it appears that there may be a delay in the delivery of adjuvant therapy associated with autologous tissue IBR, especially transverse rectus abdominis muscle (TRAM) flaps. The studies available, however, examine small numbers of patients, which makes proving statistical significance difficult. Moreover, there also appears to be no consensus on what constitutes a delay in the delivery of adjuvant therapy. From 3% to 72% of autologous tissue IBR patients seem to receive their adjuvant treatment with a delay, according to the guidelines of the respective centres. Moreover, the period of time until chemotherapy appears generally increased from 13% to 36% compared with mastectomy alone patients. The most common reasons for delay are wound and flap complications. Conclusion: At the moment, despite the increasing popularity of autologous IBR, these procedures have not proved their oncological safety. Further studies looking at the effect of IBR, especially TRAM flap reconstruction, are needed.