Migrating anterior mesoderm cells and intercalating trunk mesoderm cells have distinct responses to Rho and Rac during Xenopus gastrulation.

Rho GTPases have been shown recently to be important for cell polarity and motility of the trunk mesoderm during gastrulation in Xenopus embryos. This work demonstrated that Rho and Rac have both distinct and overlapping roles in regulating cell shape, and the dynamic properties, polarity, and type of protrusive activity of these cells. Overexpression of activated or inhibitory versions of these GTPases also disrupts development of the head in Xenopus embryos. In this study, we have undertaken a detailed analysis of Rho and Rac function in migrating anterior mesendoderm cells. Scanning electron micrographs of these cells in situ revealed that their normal shingle arrangement is disrupted and both the cells and their lamellipodia are disoriented. Anterior mesendoderm explants plated on their natural blastocoel roof matrix, however, still migrated towards the animal pole, although the tendency to move in this direction is reduced compared to controls. Analysis of a number of parameters in time-lapse recordings of dissociated cells indicated that Rho and Rac also have both distinct and overlapping roles in the motility of the prospective head mesoderm; however, their effects differ to those previously seen in the trunk mesoderm. Both GTPases appear to modulate cell polarization, migration, and protrusive activity. Rho alone, however, regulates the retraction of the lagging edge of the cell. We propose that within the gastrulating Xenopus embryo, two types of mesoderm cells that undergo different motilities have distinct responses to Rho GTPases.     

Topical use of tranexamic acid: Are there concerns for cytotoxicity?

Tranexamic acid (TXA) has revolutionized modern blood management in orthopaedic surgery, especially in total joint arthroplasty, by significantly reducing blood loss and transfusion rates. It is an antifibrinolytic agent and a synthetic derivative of the amino acid lysine, which can inhibit the activation of plasminogen and the fibrin breakdown process. The administration of TXA can be intravenous (IV), topical, and oral. In patients where the IV administration is contraindicated, topical use is preferred. Topical administration of the drug theoretically increases concentration at the operative site with reduced systemic exposure, reduces cost, and gives the surgeon the control of the administration. According to recent studies, topical administration of TXA is not inferior compared to IV administration, in terms of safety and efficacy. However, there are concerns regarding the possible toxicity in the cartilage tissue with the topical use of TXA mainly in hemiarthroplasty operations of the hip, unilateral knee arthroplasties, total knee arthroplasties where the patella is not resurfaced, and other intraarticular procedures, like anterior cruciate ligament reconstruction. The purpose of the present review is to present all the recent updates on the use of TXA focusing on the toxicity on chondrocytes and the articular cartilage that may or may not be provoked by the topical use of TXA.     

Association between MRI findings and clinical outcomes in a period of 5 years after lumbar spine microdiscectomy

European Journal of Orthopaedic Surgery & Traumatology - To evaluate the associations between magnetic resonance imaging (MRI) findings and pain, disability and quality of life before surgery...     

Low back pain in physical education teachers

The purpose of this study was to investigate the factors related to occupational low back pain (LBP) occurring in male physical education teachers (PET). The location was set in Athens and we used questionnaires to collect information. Analysis revealed that the prevalence of LBP during the survey was 63%. The correlation of personal factors and LBP showed that the prevalence of LBP was significantly higher in those PET (odds ratio, 2.5) who answered yes to the item "no personal training" than in the PET who did not. Moreover, many occupational factors are related to LBP. These were the items "lifting gym instruments" (odds ratio, 2.6) and "helping students into flexing posture" (odds ratio, 3.0). From the working conditions it was confirmed that the PET (odds ratio, 2.5) who "spent more than 35 hours per week in teaching physical education" were correlated with LBP. Our results suggest that PET, under the current working condition, are vulnerable to low back pain. An improvement of these conditions must be taken into account in order to prevent LBP.     

Normative data on hand grip strength in a Greek adult population

The objectives of this study were to establish data concerning normal hand grip strength (GS) and to explore possible associations with anthropometric parameters. GS was measured in 232 individuals in a standard arm position using the Jamar dynamometer. We examined differences between right/left and dominant/nondominant hands. Possible correlations of GS with anthropometric values were evaluated. Right hand and dominant hand GS were found to be higher and statistically significant compared to left hand and nondominant hand GS, respectively. Men had higher values of GS compared to women. A negative association was observed between age and dominant hand GS. A positive association was documented between height and dominant hand GS, while the respective comparison for weight and dominant hand GS documented a statistically significant positive association only in the male group. A positive association between BMI and dominant hand GS was seen in female individuals. Additional factors associated with GS should be the goal of future investigations.     

Studies of red cell stromal proteins in Tay-Sachs disease

Hemoglobin-free red blood cell ghosts of nine patients with Tay-Sachs disease and 14 normal control subjects have been analyzed for content of total protein, hexosamines, individual amino acids, and sialic acid. Red cell ghosts from Tay-Sachs' children have been shown to contain significantly increased amounts of protein, hexosamine, threonine, and serine, and probably sialic acid, each of which was increased by approximately 25% over control values. These observations suggest that the red cell membrane in patients with Tay-Sachs disease contains a significant excess of a glycoprotein or proteins, as compared with normal, and that the metabolic defect in this disease, therefore, affects glycoproteins as well as complex lipids.     

Radical versus postoperative radiotherapy for localized prostate cancer: a 10-year experience of an academic hospital

This study is a presentation of our department’s experience in the treatment of localized prostate cancer with either radical or postoperative radiotherapy (RT). Fifty-five patients with clinical localized prostate cancer were reviewed. Thirty-three patients (T1-T2AN0M0 stage) were treated with radical RT and 22 (T2B-T3N0M0 stage) with postoperative RT. All patients received hormonal therapy. Primary end points of the study were the incidence of clinical and biochemical recurrences and death in the whole group and according to treatment modality. Within a median follow-up of 18 months the overall incidence of clinical relapse was 16.9%, of biochemical relapse 12.7% and of death 10.9%. Both treatment options achieved similar outcomes despite the fact that the patients in the postoperative RT group were of higher stage. Radical RT group tended to have better overall and disease-free survival compared to postoperative RT group, but there was no statistically significant evidence. Long-term toxicity was negligible.     

Prevention of heterotopic ossification in high-risk patients with total hip arthroplasty: the experience of a combined therapeutic protocol

The combination of radiotherapy and indomethacin for the prevention of heterotopic ossification (HO) in high-risk patients undergoing total hip arthroplasty (THA) has not been reported. The aim of the present study was to present the experience of our department with this combined therapeutic protocol. Fifty-four patients who underwent THA received a single dose of 7 Gy of postoperative radiotherapy and 75 mg of indomethacin for 15 days. Patients were analyzed for clinical and radiographical evidence of HO development at 1 year postoperatively. The overall radiographical incidence of HO was 20.4% (95% CI 10.6–33.5%), while only 1 patient with clinically significant HO was seen. Patients with secondary arthritis due to congenital hip disease had a statistically significantly higher incidence of HO compared with those with osteoarthrosis. The clinical assessment with the Merle d’Aubigné score showed that patients with radiographic documentation of HO had a lower mean score compared with those with no evidence of HO. No treatment-related side effects were seen. Combined radiotherapy and indomethacin was effective in preventing heterotopic ossification after total hip arthroplasty. The evaluation of this efficacy compared with radiotherapy or NSAIDs alone should be the future target of larger randomized designs.

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Résumé L’association de radiothérapie et d’indométhacine pour la prévention des ossifications hétérotypiques (HO), chez les patients à haut risque, devant bénéficier d’une prothèse totale de hanche (THA) n’a jamais été rapportée. Le but de cette étude est de présenter cette expérience. Cinquante-quatre patients devant bénéficier d’une prothèse totale de hanche ont reçu une dose unique de 7 Gy en post-opératoire de radiothérapie et 75 mg d’indométhacine pendant 15 jours. Sept séries de patients ont été analysés cliniquement, radiographiquement à la recherche d’ossifications hétérotypiques au décours de la première année post-opératoire. L’incidence totale des ossifications hétérotypiques a été de 20,4% (95% CI 10.6–33.5%), un seul patient présentant une ossification gênante sur le plan clinique. Les patients présentant une coxarthrose secondaire à une luxation congénitale de hanche ont, significativement plus d’ossifications hétérotypiques que les patients présentant une coxarthrose banale. Le score de Merle d’Aubigné est significativement plus bas chez les patients présentant des ossifications hétérotypiques avec symptomatologie clinique en comparaison de ceux ne présentant que des signes radiographiques. Il n’y a aucune complication due au traitement. La combinaison radiothérapie indométhacine semble effective dans la prévention des ossifications hétérotypiques après prothèse totale de hanche. L’évaluation de son efficacité en comparaison à une radiothérapie ou à un traitement anti-inflammatoire isolé doit faire l’objet d’une plus longue étude randomisée.