Lumbar spinal fusion surgery outcomes in a cohort of injured workers in the Victorian workers' compensation system.

BACKGROUND: Lumbar spinal fusion (LSF) outcomes for workers' compensation patients are worse than for the general population. The objectives were to examine the long-term work capacity, opioid prescription and mental health outcomes of injured workers who have undergone LSF surgery in Victoria, Australia, and to identify demographic and pre- and post-operative characteristics associated with these outcomes. METHODS: Retrospective study of 874 injured workers receiving elective LSF from 2008 to 2016 in the Victorian workers' compensation system. WorkSafe Victoria's claims data were used to infer outcomes for recovery. Association of demographics, pre-surgery and surgery variables with outcomes were modelled using multivariate multinomial logistic regression analyses. RESULTS: Twenty-four months after LSF surgery, 282 (32.3%) of the 874 injured workers had substantial work capacity, 388 (44.4%) were prescribed opioids, and 330 (37.8%) were receiving mental health treatment. Opioid prescription and limited work capacity before surgery were independent strong predictors of opioid prescription, reduced work capacity and mental health treatment 24 months after LSF. Pre-operative mental health treatment was associated with the use of mental health treatment at 24 months. Other predictors for poor outcomes included a greater than 12-month duration from injury to surgery, LSF re-operation and common law or impairment benefit lodgement before surgery. CONCLUSION: An association between pre-operative factors and post-operative outcomes after LSF in a Victorian workers' compensation population was identified, suggesting that pre-operative status may influence outcomes and should be considered in LSF decisions. The high opioid use indicates that opioid management before and after surgery needs urgent review.

Identification of hypothalamic genes implicated in the development of obesity in Psammomys obesus using differential display PCR.

The hypothalamus is a key central controller of energy homeostasis and is the source and/or site of action of many neuropeptides involved in this process. The aim of this study was to isolate hypothalamic genes differentially expressed between lean and obese Psammomys obesus, a polygenic animal model of obesity and type 2 diabetes. Differential display PCR was used to compare hypothalamic gene expression profiles of lean and healthy, obese and hyperinsulinemic, and obese, diabetic P. obesus in both the fed and fasted states. We conducted differential display with 180 separate primer combinations to amplify approximately 9,000 expressed transcripts. Sixty differentially expressed bands were excised. Taqman PCR was performed on 36 of these transcripts to confirm differential gene expression in a larger sample population. Of these 36 transcripts, 9 showed homology to known genes, and 27 were considered to be novel sequences. Gene expression profiles for two of these genes are presented here. In conclusion, differential display PCR was successfully used to isolate several transcripts that may be involved in the central regulation of energy balance. We are currently conducting numerous studies to further investigate the role of these genes in the development of obesity in P. obesus.

Tanis: a link between type 2 diabetes and inflammation?

Here we describe a novel protein, which we have named Tanis, that is implicated in type 2 diabetes and inflammation. In Psammomys obesus, a unique polygenic animal model of type 2 diabetes and the metabolic syndrome, Tanis is expressed in the liver in inverse proportion to circulating glucose (P = 0.010) and insulin levels (P = 0.004) and in direct proportion with plasma triglyceride concentrations (P = 0.007). Hepatic Tanis gene expression was markedly increased (3.1-fold) after a 24-h fast in diabetic but not in nondiabetic P. obesus. In addition, glucose inhibited Tanis gene expression in cultured hepatocytes (P = 0.006) as well as in several other cell types (P = 0.001-0.011). Thus, Tanis seems to be regulated by glucose and is dysregulated in the diabetic state. Yeast-2 hybrid screening identified serum amyloid A (SAA), an acute-phase inflammatory response protein, as an interacting protein of Tanis, and this was confirmed by Biacore experiments. SAA and other acute-phase proteins have been the focus of recent attention as risk factors for cardiovascular disease, and we contend that Tanis and its interaction with SAA may provide a mechanistic link among type 2 diabetes, inflammation, and cardiovascular disease.