Cortical and trabecular bone mineral loss from the spine and hip in long-duration spaceflight.

We measured cortical and trabecular bone loss using QCT of the spine and hip in 14 crewmembers making 4- to 6-month flights on the International Space Station. There was no compartment-specific loss of bone in the spine. Cortical bone mineral loss in the hip occurred primarily by endocortical thinning. INTRODUCTION: In an earlier study, areal BMD (aBMD) measurements by DXA showed that cosmonauts making flights of 4- to 12-month duration on the Soviet/Russian MIR spacecraft lost bone at an average rate of 1%/month from the spine and 1.5%/month from the hip. However, because DXA measurements represent the sum of the cortical and trabecular compartments, there is no direct information on how these bone envelopes are affected by spaceflight. MATERIALS AND METHODS: To address this, we performed a study of crewmembers (13 males and 1 female; age range, 40-55 years) on long-duration missions (4-6 months) on the International Space Station (ISS). We used DXA to obtain aBMD of the hip and spine and volumetric QCT (vQCT) to assess integral, cortical, and trabecular volumetric BMD (vBMD) in the hip and spine. In the heel, DXA was used to measure aBMD, and quantitative ultrasound (QUS) was used to measure speed of sound (SOS) and broadband ultrasound attenuation (BUA). RESULTS AND CONCLUSIONS: aBMD was lost at rates of 0.9%/month at the spine (p < 0.001) and 1.4-1.5%/month at the hip (p < 0.001). Spinal integral vBMD was lost at a rate of 0.9%/month (p < 0.001), and trabecular vBMD was lost at 0.7%/month (p < 0.05). In contrast to earlier reports, these changes were generalized across the vertebrae and not focused in the posterior elements. In the hip, integral, cortical, and trabecular vBMD was lost at rates of 1.2-1.5%/month (p < 0.0001), 0.4-0.5%/month (p < 0.01), and 2.2-2.7%/month (p < 0.001), respectively. The cortical bone loss in the hip occurred primarily by cortical thinning. Calcaneal aBMD measurements by DXA showed smaller mean losses (0.4%/month) than hip or spine measurements, with SOS and BUA showing no change. In summary, our results show that ISS crewmembers, on average, experience substantial loss of both trabecular and cortical bone in the hip and somewhat smaller losses in the spine. These results do not support the use of calcaneal aBMD or QUS measurements as surrogate measures to estimate changes in the central skeleton.     

Comparison of outcomes and costs between laparoscopic distal pancreatectomy and open resection at a single center

Background  

The cost implications of laparoscopic distal pancreatectomy (LDP) and a detailed breakdown of hospital expenditures has not been presented in the literature to date. This study aimed to compare hospital costs and short-term clinical outcomes between LDP and open distal pancreatectomy (ODP).     

Evolving compartment syndrome not masked by a continuous peripheral nerve block: evidence-based case management

Compartment syndrome is a potentially devastating complication of many orthopedic surgeries. Whether regional anesthesia can delay the diagnosis of compartment syndrome remains a subject of debate. Previous case reports have described compartment syndrome primarily in the setting of an epidural infusion, but also following single-injection peripheral nerve blocks. A case of evolving compartment syndrome in an ambulatory setting that was not masked by a continuous peripheral nerve block is presented, followed by a discussion of the literature pertaining specifically to peripheral nerve blockade and the diagnosis of compartment syndrome. Diagnosis depends on close postoperative monitoring of analgesic use and pain trends, and patients with ambulatory catheters require thorough education about compartment syndrome so they can be evaluated in a timely manner. The current literature on compartment syndrome diagnosis and regional anesthesia is limited to case reports and expert opinion, making evidence-based recommendations difficult.     

Combined VEGF and PDGF treatment reduces secondary degeneration after spinal cord injury

Trauma to the spinal cord creates an initial physical injury damaging neurons, glia, and blood vessels, which then induces a prolonged inflammatory response, leading to secondary degeneration of spinal cord tissue, and further loss of neurons and glia surrounding the initial site of injury. Angiogenesis is a critical step in tissue repair, but in the injured spinal cord angiogenesis fails; blood vessels formed initially later regress. Stabilizing the angiogenic response is therefore a potential target to improve recovery after spinal cord injury (SCI). Vascular endothelial growth factor (VEGF) can initiate angiogenesis, but cannot sustain blood vessel maturation. Platelet-derived growth factor (PDGF) can promote blood vessel stability and maturation. We therefore investigated a combined application of VEGF and PDGF as treatment for traumatic spinal cord injury, with the aim to reduce secondary degeneration by promotion of angiogenesis. Immediately after hemisection of the spinal cord in the rat we delivered VEGF and PDGF and to the injury site. One and 3 months later the size of the lesion was significantly smaller in the treated group compared to controls, and there was significantly reduced gliosis surrounding the lesion. There was no significant effect of the treatment on blood vessel density, although there was a significant reduction in the numbers of macrophages/microglia surrounding the lesion, and a shift in the distribution of morphological and immunological phenotypes of these inflammatory cells. VEGF and PDGF delivered singly exacerbated secondary degeneration, increasing the size of the lesion cavity. These results demonstrate a novel therapeutic intervention for SCI, and reveal an unanticipated synergy for these growth factors whereby they modulated inflammatory processes and created a microenvironment conducive to axon preservation/sprouting.     

Complications after intracapsular hip fractures in young adults. A meta-analysis of 18 published studies involving 564 fractures

Intracapsular hip fractures in young adults have a significant risk of complications. Consequently, some authors advocate urgent and/or open fracture reduction. Our aim was to analyse outcomes following such fractures with reference to influence of fracture displacement, timing of surgery and method of reduction (open/closed) on the incidence of non-union (NU) and avascular necrosis (AVN). METHODS: Specific search terms were used to retrieve relevant published studies from 1966 to May 2003. RESULTS: Eighteen studies involving 564 fractures were analysed. The overall incidence of NU was 50/564 (8.9%) and AVN was 130/564 (23.0%). There was a higher incidence of NU and AVN following displaced than undisplaced fractures. NU occurred more frequently after open reduction than closed reduction (10/89 [11.2%] versus 13/275 [4.7%]). There was an increased incidence of AVN after closed than open reduction but this was no longer statistically significant when one study with a markedly higher reported incidence of AVN was excluded. The difference in the incidence of NU and AVN following early (<12h) or late (>12 h) surgery was not significant for either NU or AVN. CONCLUSION: Early or open reduction of these fractures may not reduce the risk of NU or AVN. There is a suggestion of a higher incidence of NU following open reduction than closed reduction. Randomised studies with 2 year follow-up are required to report on a larger number of patients before definite conclusions on treatment can be made.     

Complex Functional Posttraumatic Shoulder Reconstruction Using Shoulder Arthroplasty and a Pedicled Innervated Latissimus Dorsi Flap—A Case Report and Literature Review

Background

The shoulder joint is one of the most freely movable joints in the human body and has therefore high importance for upper limb functionality. Several techniques have been developed to replace the glenohumeral joint including humeral hemiarthroplasty, anatomical total shoulder arthroplasty, and reverse total shoulder arthroplasty, depending on the underlying pathology. For the soft tissue reconstruction, the innervated latissimus dorsi musculocutaneous flap is a reliable solution flap in shoulder and arm reconstruction.

Case presentation

We present the case of a 16-year-old male patient with a complete destruction of the shoulder joint and soft tissues after ballistic trauma. We performed the reconstruction of the shoulder joint using a humeral hemiarthroplasty with a mesh fixation to the remaining glenoid. The soft tissue coverage and the restoration of the deltoid muscle function were insured with a pedicled innervated latissimus dorsi musculocutaneous flap. One year postoperatively, the patient showed a good function of the shoulder joint with an excellent aesthetical result and no pain.

Conclusion

The pedicled latissimus dorsi musculocutaneous flap can safely restore the shoulder function, while the humeral hemiarthroplasty with mesh fixation can be a reliable solution for the reconstruction of a completely destructed shoulder joint.     

Mutation rates of 15 X chromosomal short tandem repeat markers

Though allele frequency data for a variety of X chromosomal short tandem repeat (STR) markers in a range of populations have been reported, fewer studies of mutation rates in these same markers or populations are available. In order to address possible mismatches during kinship analysis due to mutation, a robust estimate of the rate of mutation must be established. Here, mutation rates in three US populations have been determined for a total of 15 markers (DXS6789, DXS9902, DXS7132, DXS7130, DXS6795, DXS10147, DXS8378, DXS7423, HPRTB, DXS101, DXS7424, GATA31E08, GATA172D05, GATA165B12, and DXS6803). Eighteen mutations over 20,625 meioses were observed, and the overall X STR mutation rate in this study was found to be 8.73?×?10^?4 (95 % CI, 5.2–13.8?×?10^?4). A review of published mutation rate studies revealed similar findings in other global populations, and allowed the compilation of a combined dataset of 81,310 meioses which can be employed by the forensic community.     

The distribution of urate deposition within the extremities in gout: a review of 148 dual-energy CT cases

Objective

Clinical detection of gout can be difficult due to co-existent and mimicking arthropathies and asymptomatic disease. Understanding of the distribution of urate within the body can aid clinical diagnosis and further understanding of the resulting pathology. Our aim was to determine this distribution of urate within the extremities in patients with gout.

Materials and methods

All patients who underwent a four-limb dual-energy computed tomography (DECT) scan for suspected gout over a 2-year period were identified (n?=?148, 121 male, 27 female, age range, 16–92 years, mean?=?61.3 years, median?=?63 years). The reports of the positive cases were retrospectively analyzed and the locations of all urate deposition recorded and classified by anatomical location.

Results

A total of 241 cases met the inclusion criteria, of which 148 cases were positive. Of these, 101 (68.2 %) patients had gout in the foot, 81 (56.1 %) in the knee, 79 (53.4 %) in the ankle, 41 (27.7 %) in the elbow, 25 (16.9 %) in the hand, and 25 (16.9 %) in the wrist. The distribution was further subcategorized for each body part into specific bone and soft tissue structures.

Conclusions

In this observational study, we provide for the first time a detailed analysis of extremity urate distribution in gout, which both supports and augments to the current understanding based on clinical and microscopic findings.     

Isolation of primary endothelial and stromal cell cultures of the corpus cavernosum penis for basic research and tissue engineering

OBJECTIVES: Primary cell cultures derived from the corpus cavernosum are frequently used as in vitro models to define cellular mechanisms involved in erectile function. However, previous studies often lack detailed isolation protocols or a precise characterisation of the culture composition excluding especially contaminating fibroblasts. This study aimed at critically analysing and reproducing reported isolation methods, as well as establishing new procedures to receive highly pure and morphologically differentiated endothelial, smooth muscle and fibroblastic cells derived from the human penis. METHODS: We evaluated numerous isolation and enrichment techniques using cavernosal tissue from 57 patients. Assessment factors displayed the purity, cell yield, practicability and reproducibility. The purity in cultured cells was analysed using immunocytochemistry and Western blots. RESULTS: An enzymatic protocol was established for the isolation and cultivation of cavernosal endothelial cells with an impressive purity of 98.0+/-0.8%. In contrast, already published nearly pure smooth muscle cell cultures were not reproducible in our laboratory. Meaningful evidence for an overwhelming presence of fibroblasts in these widely accepted pure smooth muscle cell cultures is presented. CONCLUSION: Endothelial cell cultures derived from human corpora cavernosa are reproducible and reliable to serve for cell culture-based investigations of the endothelial dysfunction. The discrepancy in the purity of smooth muscle cell cultures might reflect laboratory and tissue source factors, lacking an exclusion of fibroblasts in other studies or changes in stromal phenotype under culture conditions. Further research is necessary to clarify a possible plasticity between smooth muscle cells and (myo)fibroblasts and assess functional properties.