The diagnosis of hypogonadism in human males includes identification of low serum testosterone levels, and hence there is an underlying assumption that normal ranges of testosterone for the healthy population are known for all ages. However, to our knowledge, no such reference model exists in the literature, and hence the availability of an applicable biochemical reference range would be helpful for the clinical assessment of hypogonadal men. In this study, using model selection and validation analysis of data identified and extracted from thirteen studies, we derive and validate a normative model of total testosterone across the lifespan in healthy men. We show that total testosterone peaks [mean (2.5–97.5 percentile)] at 15.4 (7.2–31.1) nmol/L at an average age of 19 years, and falls in the average case [mean (2.5–97.5 percentile)] to 13.0 (6.6–25.3) nmol/L by age 40 years, but we find no evidence for a further fall in mean total testosterone with increasing age through to old age. However we do show that there is an increased variation in total testosterone levels with advancing age after age 40 years. This model provides the age related reference ranges needed to support research and clinical decision making in males who have symptoms that may be due to hypogonadism.

Activity-based rehabilitation is a promising strategy for improving functional recovery following spinal cord injury (SCI). While results from both clinical and animal studies have shown that a variety of approaches can be effective, debate still exists regarding the optimal post-injury period to apply rehabilitation. We recently demonstrated that rats with moderately severe thoracic contusive SCI can be re-trained to swim when training is initiated 2 weeks after injury and that swim training had no effect on the recovery of overground locomotion. We concluded that swim training is a task-specific model of post-SCI activity-based rehabilitation. In the present study, we ask if re-training initiated acutely is more or less effective than when initiated at 2 weeks post-injury. Using the Louisville Swim Scale, an 18-point swimming assessment, supplemented by kinematic assessment of hindlimb movement during swimming, we report that acute re-training is less effective than training initiated at 2 weeks. Using the bioluminescent protein luciferase as a blood-borne macromolecular marker, we also show a significant increase in extravasation in and around the site of SCI following only 8 min of swimming at 3 days post-injury. Taken together, these results suggest that acute re-training in a rat model of SCI may compromise rehabilitation efforts via mechanisms that may involve one or more secondary injury cascades, including acute spinal microvascular dysfunction.

Anterior capsular reconstruction needs to be done for most cases of anterior shoulder instability. Several surgical techniques using tendinous allografts and autografts have been used for the treatment of anterior glenohumeral capsular reconstruction. However, the outcomes of these procedures are not satisfactory. This study describes a comparatively new technique of using human acellular dermal allograft (GraftJacket: Wright Medical Group, Memphis, TN) in the reconstruction of the anterior capsule to restore anterior glenohumeral stability.

Transgenic mice overexpressing human progastrin (hGAS) show colonic crypt hyper-proliferation and elevated susceptibility to colon carcinogenesis. We aimed to investigate effects of p53 mutation on colon carcinogenesis in hGAS mice. We show that introducing a p53 gene mutation further increases progastrin dependent BrdU labeling and results in markedly elevated number of aberrant crypt foci (ACF) and colonic tumors. We demonstrate that hGAS/Lgr5-GFP mice have higher number of Lgr5+ colonic stem cells per crypt when compared to Lgr5-GFP mice indicating that progastrin changes crypt biology through increased stem cell numbers and additional p53 mutation leads to more aggressive phenotype in this murine colon cancer model.

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