FEM Simulation of Non-Progressive Growth from Asymmetric Loading and Vicious Cycle Theory: Scoliosis Study Proof of Concept

Scoliosis affects about 1-3% of the adolescent population, with 80% of cases being idiopathic. There is currently a lack of understanding regarding the biomechanics of scoliosis, current treatment methods can be further improved with a greater understanding of scoliosis growth patterns. The objective of this study is to develop a finite element model that can respond to loads in a similar fashion as current spine biomechanics models and apply it to scoliosis growth. Using CT images of a non-scoliotic individual, a finite element model of the L3-L4 vertebra was created. By applying asymmetric loading in accordance to the ‘vicious cycle’ theory and through the use of a growth modulation equation it is possible to determine the amount of growth each region of the vertebra will undergo; therefore predict scoliosis growth over a period of time. This study seeks to demonstrate how improved anatomy can expand researchers current knowledge of scoliosis

IGL-1 solution reduces endoplasmic reticulum stress and apoptosis in rat liver transplantation

Injury due to cold ischemia reperfusion (I/R) is a major cause of primary graft non-function following liver transplantation. We postulated that I/R-induced cellular damage during liver transplantation might affect the secretory pathway, particularly at the endoplasmic reticulum (ER). We examined the involvement of ER stress in organ preservation, and compared cold storage in University of Wisconsin (UW) solution and in Institute Georges Lopez-1 (IGL-1) solution. In one group of rats, livers were preserved in UW solution for 8 h at 4 °C, and then orthotopic liver transplantation was performed according to Kamada's cuff technique. In another group, livers were preserved in IGL-1 solution. The effect of each preservation solution on the induction of ER stress, hepatic injury, mitochondrial damage and cell death was evaluated. As expected, we found increased ER stress after liver transplantation. IGL-1 solution significantly attenuated ER damage by reducing the activation of three pathways of unfolded protein response and their effector molecules caspase-12, C/EBP homologous protein-10, X-box-binding protein 1, tumor necrosis factor-associated factor 2 and eukaryotic translation initiation factor 2. This attenuation of ER stress was associated with a reduction in hepatic injury and cell death. Our results show that IGL-1 solution may be a useful means to circumvent excessive ER stress reactions associated with liver transplantation, and may optimize graft quality

Numerical Simulation of Asymmetrically Altered Growth as Initiation Mechanism of Scoliosis

The causes of idiopathic scoliosis are still uncertain; buckling is mentioned often, but never proven. The authors hypothesize another option: unilateral postponement of growth of MM Rotatores or of ligamentum flavum and intertransverse ligament. In this paper, both buckling and the two new theories of scoliotic initiation are studied using a new finite element model that simulates the mechanical behavior of the human spine. This model was validated by the stiffness data of Panjabi et al. (J. Biomech. 9:185–192, 1976). After a small correction of the prestrain of some ligaments and the MM Rotatores the model appeared to be valid. The postponement in growth was translated in the numerical model in an asymmetrical stiffness. The spine was loaded axially and the resulting deformation was analyzed for the presence of the coupling of lateral deviation and axial rotation that is characteristic for scoliosis. Only unilateral postponement of growth of ligamentum flavum and intertransverse ligament appeared to initiate scoliosis. Buckling did not initiate scoliosis

Detection of Coxiella burnetii DNA in animal and environmental matrices on non-dairy sheep farms

During the spring and summer of 2007, 2008 and 2009, large Q fever outbreaks occurred in the Netherlands affecting a rural area in the southeast of the country. Prior to and during these outbreaks Q fever related abortion waves were reported on several dairy goat farms in the same region. As a result, primarily commercial dairy goat farms were implicated as potential sources for the emerging human Q fever cases in the Netherlands. However, in 2008 and 2009 a number of (non-dairy) sheep farms were identified where C. burnetii DNA was detected in both animal (vaginal swabs) and environmental (surface area swabs) matrices. In addition, in two epidemiological studies non-dairy sheep farms were implicated as the primary source for an emerging cluster of human Q fever cases in their near vicinity. Therefore, although less important in the recent epidemic, non-dairy sheep farms cannot be ruled out as potential source for human Q fever. In the current study, we describe the presence of C. burnetii DNA in animal and environmental matrices obtained from two non-dairy sheep farms. We show that C. burnetii DNA content in surface area swabs from fences and drinking buckets and udder swabs from animals was consistently higher on farm B in comparison to farm A. This may be explained by the geographical locations of the farms, since farm B is located in a highly Q fever affected area (Noord-Brabant), while farm A is located in an area not affected by Q fever (Noord-Holland). How these results are related to shedding of C. burnetii by the non-dairy sheep on these farms is not clear. No positive relationship was found between C. burnetii content in vaginal swabs and udder swabs. Coxiella burnetii contamination of sheep udders may be a result from excrements from the same animal, direct contact with other animals (or other contaminated surfaces), or a combination of these.VW

Q fever: the answer is blowing in the wind : Detection of Coxiella burnetii in aerosols

Coxiella burnetii is a bacterium that causes Q fever, a zoonosis that affects large numbers of both humans and animals. From 2007 to 2010, large outbreaks of Q fever were observed in a rural area in the Netherlands. In 2009, field studies were started to investigate if C. burnetii DNA can be detected in aerosols on and in the near vicinity of Q fever affected farms. In 2010, these studies were continued in two areas studied in 2009, in the provinces of Noord-Brabant and Zuid-Limburg, to investigate if C. burnetii DNA was still present in aerosols in these areas. In both areas, the C. burnetii DNA content in aerosols obtained in 2010 seemed to have declined in comparison to data of the same locations visited in 2009. These data are in agreement with the observed reduction in the number of reported Q fever cases in 2010 in comparison to 2009. Possible explanations for this decline could be the start of a mandatory vaccination campaign for small ruminants in 2009 and the culling of pregnant animals on Q fever affected farms that started at the end of 2009. This data will be used in future investigations, in which we will combine molecular detection and typing methods for C. burnetii in aerosols with mathematical modelling to get more insight in the transmission of C. burnetii via aerosols and track (individual) sources for C. burnetii infection.VW