Architecture of a transcribing-translating expressome.

DNA transcription is functionally coupled to messenger RNA (mRNA) translation in bacteria, but how this is achieved remains unclear. Here we show that RNA polymerase (RNAP) and the ribosome of Escherichia coli can form a defined transcribing and translating "expressome" complex. The cryo-electron microscopic structure of the expressome reveals continuous protection of ~30 nucleotides of mRNA extending from the RNAP active center to the ribosome decoding center. The RNAP-ribosome interface includes the RNAP subunit α carboxyl-terminal domain, which is required for RNAP-ribosome interaction in vitro and for pronounced cell growth defects upon translation inhibition in vivo, consistent with its function in transcription-translation coupling. The expressome structure can only form during transcription elongation and explains how translation can prevent transcriptional pausing, backtracking, and termination.

Usefulness of Video Review of Possible Concussions in National Youth Rugby League.

A new concussion interchange rule (CIR) was introduced in 2014 for the National Rugby League and National Youth Competition (NYC). The CIR allows a player suspected of having sustained a concussion to be removed from play and assessed without an interchange being tallied against the player's team. Participants included all NYC players who used the CIR during the 2014 season. 2 raters completed video analysis of 131 (of a total of 156 reported) uses of the CIR, describing injury characteristics, situational factors, and concussion signs. The incidence rate was 44.9 (95% CI: 38.5-52.3) uses of the CIR per 1 000 NYC player match hours, or approximately one CIR use every 1.3 games. Apparent loss of consciousness/unresponsiveness was observed in 13% of cases, clutching the head in 65%, unsteadiness of gait in 60%, and a vacant stare in 23%. Most incidences occurred from a hit-up (82%). There appeared to be some instances of video evidence of injury but the athlete was cleared to return to play in the same game. Video review appears to be a useful adjunct for identifying players suffering possible concussion. Further research is required on the usefulness of video review for identifying signs of concussive injury.

Emerging roles of calcium-activated K channels and TRPV4 channels in lung oedema and pulmonary circulatory collapse.

It has been suggested that the transient receptor potential cation (TRP) channel subfamily V (vanilloid) type 4 (TRPV4) and intermediate conductance calcium-activated potassium (KCa3.1) channels contribute to endothelium-dependent vasodilation. Here, we summarize very recent evidence for a synergistic interplay of TRPV4 and KCa3.1 channels in lung disease. Among the endothelial Ca2+ -permeable TRPs, TRPV4 is best characterized and produces arterial dilation by stimulating Ca2+ -dependent nitric oxide synthesis and endothelium-dependent hyperpolarization. Besides these roles, some TRP channels control endothelial/epithelial barrier functions and vascular integrity, while KCa3.1 channels provide the driving force required for Cl- and water transport in some cells and most secretory epithelia. The three conditions, increased pulmonary venous pressure caused by left heart disease, high inflation pressure and chemically induced lung injury, may lead to activation of TRPV4 channels followed by Ca2+ influx leading to activation of KCa3.1 channels in endothelial cells ultimately leading to acute lung injury. We find that a deficiency in KCa3.1 channels protects against TRPV4-induced pulmonary arterial relaxation, fluid extravasation, haemorrhage, pulmonary circulatory collapse and cardiac arrest in vivo. These data identify KCa3.1 channels as crucial molecular components in downstream TRPV4 signal transduction and as a potential target for the prevention of undesired fluid extravasation, vasodilatation and pulmonary circulatory collapse.

Endothelial Small- and Intermediate-Conductance K Channels and Endothelium-Dependent Hyperpolarization as Drug Targets in Cardiovascular Disease.

Endothelial calcium/calmodulin-gated K channels of small (KCa2.3) and intermediate conductance (KCa3.1) produce membrane hyperpolarization and endothelium-dependent hyperpolarization (EDH)-mediated vasodilation. Dysfunctions of the two channels and ensuing EDH impairments are found in several cardiovascular pathologies such as diabetes, atherosclerosis, postangioplastic neointima formation, but also inflammatory disease, cancer, and organ fibrosis. Moreover, KCa3.1 plays an important role in endothelial barrier dysfunction, edema formation in cardiac and pulmonary disease, and in ischemic stroke. Concerning KCa2.3, genome-wide association studies revealed an association of KCa2.3 channels with atrial fibrillation in humans. Accordingly, both channels are considered potential drug targets for cardio- and cerebrovascular disease states. In this chapter, we briefly review the function of the two channels in EDH-type vasodilation and systemic circulatory regulation and then highlight their pathophysiological roles in ischemic stroke as well as in pulmonary and brain edema. Finally, the authors summarize recent advances in the pharmacology of the channels and explore potential therapeutic utilities of novel channel modulators.

Pathologically confirmed breast cancer in Malawi: a descriptive study: Clinical profile of breast cancer.

BACKGROUND: Breast cancer is the most common female cancer in Africa, yet no published studies have investigated breast cancer in Malawi. Understanding the clinical profile of breast cancer is important to develop early diagnosis efforts. AIM: To describe clinical and pathological characteristics of breast specimens from a pathology laboratory at a national teaching hospital. METHODS: Secondary analysis of pathology reports from July 2011 to September 2013. RESULTS: Among 85 breast cancer cases, 55% were < 50 years. Median tumor size was 4 cm and 49% were grade 3. Median symptom duration was eight months. CONCLUSIONS: Malawian women with breast cancer commonly have long symptom durations prior to diagnosis, young age, and poorly differentiated tumors. Improved clinical and pathological characterization, including hormone receptor status, are urgently needed to better understand this disease in Malawi.

Tax contributes apoptosis resistance to HTLV-1-infected T cells via suppression of Bid and Bim expression.

The human T-lymphotropic virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia (ATL). HTLV-1 Tax has been shown to have a prosurvival role in infected T cells by enhancing expression of the Bcl-2 family of antiapoptotic proteins. In this study, we show that the expression of proapoptotic BH3-only proteins Bim (Bcl-2-interacting mediator of cell death) and Bid (BH3-interacting domain death agonist) is diminished in HTLV-1-infected leukemic cells. Using a Tax-inducible system and a transient overexpression approach, we demonstrate that Tax downregulates Bid and Bim expression at the transcriptional level. We show that reinforced expression of Bim and Bid in HTLV-1-infected T-cell lines sensitizes CD95/TRAIL- and anticancer drug-induced apoptosis. Furthermore, we show that Tax suppresses Bid and Bim expression by enhancing hypoxia-inducible factor-1α (HIF-1α) protein expression. siRNA knockdown of HIF-1α or chemical inhibition of the transactivation activity of HIF-1α resulted in an increase in Bid and Bim expression and, consequently, in an increase in CD95/TRAIL- and anticancer drug-induced apoptosis in HTLV-1-infected leukemic T-cell lines. Our study provides evidence that besides upregulation of prosurvival Bcl-2 proteins, Tax may also confer apoptosis resistance to HTLV-1-infected T cells by suppressing the expression of the proapoptotic BH3-only proteins Bim and Bid.

Impact of balloon inflation pressure on cell viability with single and multi lumen catheters.

Infusion catheters, when used in combination with balloons, are subjected to pressure created by inflation of the balloon. The compression can reduce the catheter flow area and cause elevated shear stresses in the fluid. A model and experiments were developed with a range of applied balloon pressures to investigate whether such situations may cause cell lysis during stem-cell infusion through single-lumen catheters. It was found that for balloon inflation pressures in excess of ~7 atm, it is possible for cell injury to occur, although the critical pressure depends on the fluid viscosity. The study was then applied to a multi-lumen catheter which was designed to resist compression. That device was able to handle very elevated balloon pressures and flow rates before cell lysis became a concern.

Osteoid osteoma of the proximal femur: treatment by percutaneous bone resection and drilling (PBRD). A report of 44 cases.

INTRODUCTION: Osteoid osteoma is a benign osteogenic tumor that is mainly located in the lower limbs. According to Campanacci the proximal femur is involved in 25% of cases. We present a series of 44 cases of osteoid osteoma located in the neck of the femur or the lesser trochanter treated by the minimally invasive method, CT-guided percutaneous bone resection and drilling (PBRD). MATERIALS AND METHODS: This series included 44 patients, 20 girls and 24 boys, treated between 1987 and 2012. The average age at surgery was 12.7 years old (range 4-34). The diagnosis was based on the "association" of scintigraphy (hyperfixation) - CT scan (nidus located on the femoral neck or near the lesser trochanter). These patients underwent CT-guided PBRD under general anesthesia. Specific ancillary material was used to reach and remove the nidus and a cylinder of bone was sent to the pathologist for assessment. A lateral or anterior approach was used in all cases except one in which a posterior incision was made. Histological confirmation was obtained in 23 cases (the bone fragment was damaged in 21 cases). RESULTS: Forty-two patients were reviewed after a minimum follow-up of one year (12-56 months). Two patients were lost to follow-up. Results were evaluated clinically and on CT scan 1 year after surgery: there were 35 cures with complete and permanent pain relief. There were 5 failures and 1 case of recurrence requiring a second CT-guided PBRD procedure as well 2 complications involving femoral fracture (one associated with failure). DISCUSSION: The proximal femur is a common location of osteoid osteoma. Treatment requires careful preoperative planning to determine the surgical approach for safe removal. PBRD is a minimally invasive technique, allowing complete resection with suitable ancillary equipment. This method should be compared with thermoablation, which is a similar technique. CONCLUSION: CT-guided PBRD is a therapeutic option in case of osteoid osteoma of the proximal femur. LEVEL OF EVIDENCE: Level IV.

Congenital dislocation of the hip: optimal screening strategies in 2014.

A prospective multi-centre nationwide study of patients with congenital dislocation of the hip (CDH) diagnosed after 3 months of age was conducted with support from the French Society for Paediatric Orthopaedics (Société Française d'Orthopédie Pédiatrique [SoFOP]), French Organisation for Outpatient Paediatrics (Association Française de Pédiatrie Ambulatoire [AFPA]), and French-Speaking Society for Paediatric and Pre-Natal Imaging (Société Francophone d'Imagerie Pédiatrique et Prénatale [SFIPP]). The results showed inadequacies in clinical screening for CDH that were patent when assessed quantitatively and probably also present qualitatively. These findings indicate a need for a communication and educational campaign aimed at highlighting good clinical practice guidelines in the field of CDH screening. The usefulness of routine ultrasound screening has not been established. The findings from this study have been used by the authors and French National Health Authority (Haute Autorité de Santé [HAS]) to develop recommendations about CDH screening. There is an urgent need for a prospective randomised multi-centre nationwide study, which should involve primary-care physicians.

Minimally invasive repair of pectus excavatum using the Nuss technique in children and adolescents: indications, outcomes, and limitations.

BACKGROUND: Pectus excavatum (PE) is a common congenital deformity. The Nuss technique for minimally invasive repair of PE involves thoracoscopy-assisted insertion of a bar or plate behind the deformity to displace the sternum anteriorly. Our objective here was to clarify the indications and limitations of the Nuss technique based on a review of 70 patients. MATERIALS AND METHODS: A retrospective review of children managed at two centres identified 70 patients who had completed their growth and had their plate removed. Mean age was 13.8 years (range, 6-19 years). The reason for surgery was cosmetic disfigurement in 66 (95%) patients. The original Nuss technique was used in 63 patients, whereas 7 patients required an additional sub-xiphoid approach. Time to implant removal ranged from 8 months to 3 years. RESULTS: The cosmetic outcome was considered satisfactory by the patients in 64 (91%) cases and by the surgeon in 60 (85.7%) cases. Major complications requiring further surgery occurred in 6 (8.5%) patients and consisted of haemothorax (n=2), chest wall sepsis (n=2, including 1 after implant removal), allergy (n=1), and implant displacement (n=1). Early or delayed minor complications occurred in 46 (65%) patients and resolved either spontaneously or after non-surgical therapy. DISCUSSION: The minimal scarring and reliably good outcomes support the widespread use of the Nuss technique in children and adolescents. Our complication rates (minor, 65%; and major, 8.5%) are consistent with previous publications. In our opinion, contra-indications to thoracoscopic PE correction consist of a history of cardio-thoracic surgery and the finding by computed tomography of a sternum-to-spine distance of less than 5 cm or of sternum rotation greater than 35°. In these situations, we recommend a sub- and retro-xiphoid approach to guide implant insertion or a classic sterno-chondroplasty procedure. LEVEL OF EVIDENCE: Level IV, retrospective descriptive cohort study.

Direct costs associated with the management of progressive early onset scoliosis: estimations based on gold standard technique or with magnetically controlled growing rods.

BACKGROUND: The main disadvantage of the surgical management of early onset scoliosis (EOS) using conventional growing rods is the need for iterative surgical procedures during childhood. The emergence of an innovative device using distraction-based magnetically controlled growing rods (MCGR) provides the opportunity to avoid such surgeries and therefore to improve the patient's quality of life. HYPOTHESIS: Despite the high cost of MCGR and considering its potential impact in reducing hospital stays, the use of MCGR could reduce medical resource consumption in a long-term view in comparison to traditional growing rod (TGR). MATERIALS AND METHODS: A cost-simulation model was constructed to assess the incremental cost between the two strategies. The cost for each strategy was estimated based on probability of medical resource consumption determined from literature search as well as data from EOS patients treated in our centre. Some medical expenses were also estimated from expert interviews. The time horizon chosen was 4 years as from first surgical implantation. Costs were calculated in the perspective of the French sickness fund (using rates from year 2013) and were discounted by an annual rate of 4%. Sensitivity analyses were conducted to test model strength to various parameters. RESULTS: With a time horizon of 4 years, the estimated direct costs of TGR and MCGR strategies were 49,067 € and 42,752 €, respectively leading to an incremental costs of 6135 € in favour of MCGR strategy. In the first case, costs were mainly represented by hospital stays expenses (83.9%) whereas in the other the cost of MCGR contributed to 59.5% of the total amount. In the univariate sensitivity analysis, the tariffs of hospital stays, the tariffs of the MCG, and the frequency of distraction surgeries were the parameters with the most important impact on incremental cost. DISCUSSION: MCGR is a recent and promising innovation in the management of severe EOS. Besides improving the quality of life, its use in the treatment of severe EOS is likely to be offset by lower costs of hospital stays. LEVEL OF EVIDENCE (WITH STUDY DESIGN): Level IV, economic and decision analyses, retrospective study.

Serum biomarkers of clinical and cytologic response in dogs with idiopathic immune-mediated polyarthropathy.

BACKGROUND: Immune-mediated polyarthopathy (IMPA) is common in dogs, and is monitored by serial arthrocenteses. HYPOTHESIS/OBJECTIVES: Plasma C-reactive protein (CRP), interleukin-6 (IL-6), and CXCL8 (interleukin-8) would serve as noninvasive markers of joint inflammation in IMPA. ANIMALS: Nine client-owned dogs with idiopathic IMPA; 6 healthy controls. METHODS: Prospective study. Plasma CRP, IL-6, and CXCL8 were measured by ELISA at baseline, 2, and 4 weeks during treatment with prednisone at 50 mg/m(2) /day. Arthrocenteses, the canine brief pain inventory (CBPI), and accelerometry collars were used to assess joint inflammation, lameness, and mobility at all 3 time points. RESULTS: C-reactive protein concentrations were higher in IMPA dogs (median 91.1 µg/mL, range 76.7-195.0) compared with controls (median <6.3 µg/mL, <6.3-13.7; P = .0035), and were significantly lower at week 2 (10.6 µg/mL, <6.3-48.8) and week 4 (<6.3 µg/mL, <6.3-24.4; P < .001). C-reactive protein was correlated with median CBPI scores (r = 0.68; P = .0004), joint cellularity (r = 0.49, P = .011), and mobility by accelerometry (r = -0.42, P = .048). Plasma IL-6 concentrations were also higher in IMPA dogs (median 45.9 pg/mL), compared with controls (median <15.7 pg/mL; P = .0008). IL-6 was lower in IMPA dogs by week 4 (<15.7 pg/mL; P = .0099), and was modestly correlated with CBPI scores (r = 0.47, P = .023). CXCL8 did not differ significantly between IMPA and healthy dogs. CONCLUSIONS: Plasma CRP and IL-6 might be useful surrogate markers of synovial inflammation and disease activity in dogs with IMPA.

Induced-membrane femur reconstruction after resection of bone malignancies: three cases of massive graft resorption in children.

Bone reconstruction after surgical resection of bone malignancies in children remains a difficult challenge. Induced-membrane reconstruction as described by Masquelet et al. was originally reported in traumatic or septic bone defects and is now adapted to this field. We report here three cases of massive femoral graft resorption requiring surgical revision in two boys aged 3 and 6 years and a 9-year-old girl. Hypotheses include the long delay between the two stages, nature of the bone graft, high varus loads specific to this location, and lack of stability of the fixation. This technique has recently provided promising preliminary results when applied to the field of bone tumours. However, reconstruction of the femur seems to be specifically associated with a risk of graft resorption. Identification of the origin of this major complication is needed to amend the technique or its indications.

Osteoid osteoma of the acetabular fossa: five cases treated with percutaneous resection.

BACKGROUND: Osteoid osteoma is a painful benign osteogenic tumour for which the treatment objective is surgical resection of the nidus. The acetabular fossa is an uncommon site of involvement where surgical access can prove challenging. MATERIALS AND METHODS: We report a case-series composed of five patients with osteoid osteoma of the acetabular fossa treated with percutaneous bone resection and drilling under computed tomography guidance. RESULTS: All five patients had an uneventful postoperative course with immediate pain relief that was sustained over time. DISCUSSION: The outcomes achieved using our percutaneous technique compare favourably with those of other percutaneous methods, most notably regarding pain relief and patient tolerance of the procedure. CONCLUSION: Percutaneous bone resection and drilling under computed tomography guidance proved effective for the treatment of osteoid osteoma involving the acetabular fossa. LEVEL OF EVIDENCE: Level IV.

Fractures in children younger than 18 months.

Fractures in children younger than 18 months occur before the usual walking age. The prognosis is favourable across fracture types and circumstances of occurrence. The cause is obvious in obstetrical injuries, whose risk factors have been well documented. Diaphyseal fractures are easy to recognise, whereas challenges may arise with the diagnosis of physeal injuries. Fractures occurring after the neonate is discharged home may be due to accidental falls related to clumsiness on the part of the carers. Other possibilities, however, are child abuse and abnormal bone fragility. Thus, the aetiological diagnosis has major medical, social, and legal implications. Identifying the aetiology is often extremely difficult and benefits from the involvement of a multidisciplinary team. The literature review presented herein is designed to assist orthopaedic surgeons in the diagnosis and management of children with fractures before 18 months of age, in compliance with French legislation, which has undergone major changes over the last quarter century.

[Surgery for severe aspirations]. / Chirurgie de la déglutition dans le traitement d'aspirations récidivantes.

Severe dysphagia resulting in repeated aspirations and pneumonia are difficult to treat with swallowing therapy and surgical treatment is often required. Our study retrospectively reviews our experience with 19 such cases operated by laryngeal suspension and laryngotracheal separation. Restoration of oral nutrition was possible in 45% of laryngeal suspension cases and in 75% of laryngotracheal separation operations. These surgical techniques prevent severe aspirations while conserving phonation, contrarily to total laryngectomy. Tracheocutaneous fistulas were frequent, especially after radiation, implying that the surgical technique should be modified in the future.

Osteoid osteoma transformation into osteoblastoma: fact or fiction?

BACKGROUND: Osteoid osteoma and osteoblastoma are rare, benign, bone-forming tumours. The clinical presentation, imaging study findings, and course indicate clearly that these two tumours are distinct entities. CLINICAL REPORTS: We report two cases suggesting transformation of osteoid osteoma into osteoblastoma and therefore inviting a discussion of the links between these two tumours. An 11-year-old girl with a small metaphyseal lesion of the proximal tibia was given a diagnosis of osteoid osteoma. Over the next few weeks, worsening pain and marked tumour growth prompted a biopsy, which was consistent with an aggressive osteoblastoma. A review of the case suggested primary osteoblastoma at the earliest stage of development. In a 14-year-old boy, en-bloc excision was performed to remove a 1cm defect located within the femoral shaft cortex and typical for osteoid osteoma. An asymptomatic recurrence measuring 20mm along the long axis was removed 18 months later. Reassessment of the histological slides indicated recurrence of an incompletely excised osteoid osteoma. DISCUSSION: The histological similarities between osteoid osteoma and osteoblastoma, together with the lesion size criterion, may result in confusion. Collaboration between the clinician and pathologist is crucial and should take the tempo of evolution into account. CONCLUSION: The histopathological differences between these two tumour types deserve to be emphasized. The data reported here challenge the concept that osteoid osteoma can transform into osteoblastoma. These two tumours are distinct entities that should no longer be differentiated based on size, as was long done in the past.

Early surgical anterior release for congenital and isolated elbow contracture in flexion: a case report of a 16-month-old child.

Isolated congenital elbow contracture is a rare upper-extremity disorder and there are few data about management of this condition. Authors report their experience after aggressive management of children with isolated congenital elbow contracture in flexion. Because of total absence of range of motion (ROM) improvement despites physical therapy (ROM 90-120°) and bone deformity, an anterior surgical release of the elbow was performed through an extensive lateral approach, at sixteen months of age. After surgery, this child was treated by three casts at maximal gained extension followed by sequential Turnbuckles splints. After five years of follow-up, the result was excellent with ROM 5-135°, normal function and absence of growth disturbance. The limiting factor of this protocol was excessive traction in elbow extension on the neurovascular structures, especially the radial nerve. This treatment represents an aggressive management with multiple general anaesthesia, but was found to be a valid option.

Induced membrane technique for reconstruction after bone tumor resection in children: a preliminary study.

AIM: Segmental long-bone defect due to tumor resection remains a challenge to treat. The induced membrane technique is a new alternative for biological reconstruction. During the first stage, a cement spacer is inserted after bone resection and stabilisation. The cement spacer is removed during a second stage procedure performed after chemotherapy, and cortico-cancellous bone autograft was placed in the biological induced chamber. The aim of this study was to assess preliminary results in eight children. PATIENTS AND METHODS: This prospective study included six girls and two boys, with a mean age of 12.1 years (range 9.5 to 18) and treated for a mean 15 cm defect (range 10 to 22 cms) due to resection of osteosarcoma (n=4), Ewing sarcoma (n=3) and low grade sarcoma. All patients except one, were given pre- and postoperative chemotherapy. Surgery was performed for three patients with a distal femur tumor, two patients with a proximal tibial tumor and three patients who had proximal humerus, shaft of humerus and fibular tumors. Fixation was mainly performed with locking compression plate (n=4) and locked nail (n=2). The mean operating times for first and second step procedures were 4.8 and 4h respectively. The healing process was radiologically assessed. RESULTS: After a mean follow-up of 21.6 months (15 to 30), all patients were free of disease and seven had bony union. For the lower limb reconstructions, full weight bearing was possible after a mean of 116 days (range 90 to 150) following the second stage. Mean time to bone union was 4.8 months (1.5 to 10). The early Musculoskeletal Tumor Society (MSTS) score was 25.2/30 (range 20-30). Complications were: non-union (n=1), paradoxical graft resorption (n=1) requiring graft revision. CONCLUSION: This two stage procedure reduces the operating time during the first stage and it also reduces early complications. Rapid bone union is objectively obtained despite major bone resection and the patients receiving chemotherapy. SIGNIFICANCE: The induced membrane technique could be an excellent alternative for biological reconstruction after tumor resection in children.