A repeating fast radio burst source localized to a nearby spiral galaxy.

Fast radio bursts (FRBs) are brief, bright, extragalactic radio flashes1,2. Their physical origin remains unknown, but dozens of possible models have been postulated3. Some FRB sources exhibit repeat bursts4-7. Although over a hundred FRB sources have been discovered8, only four have been localized and associated with a host galaxy9-12, and just one of these four is known to emit repeating FRBs9. The properties of the host galaxies, and the local environments of FRBs, could provide important clues about their physical origins. The first known repeating FRB, however, was localized to a low-metallicity, irregular dwarf galaxy, and the apparently non-repeating sources were localized to higher-metallicity, massive elliptical or star-forming galaxies, suggesting that perhaps the repeating and apparently non-repeating sources could have distinct physical origins. Here we report the precise localization of a second repeating FRB source6, FRB 180916.J0158+65, to a star-forming region in a nearby (redshift 0.0337 ± 0.0002) massive spiral galaxy, whose properties and proximity distinguish it from all known hosts. The lack of both a comparably luminous persistent radio counterpart and a high Faraday rotation measure6 further distinguish the local environment of FRB 180916.J0158+65 from that of the single previously localized repeating FRB source, FRB 121102. This suggests that repeating FRBs may have a wide range of luminosities, and originate from diverse host galaxies and local environments.

Usefulness of point-of-care ultrasound in military medical emergencies performed by young military medicine residents.

INTRODUCTION: To evaluate the usefulness of point-of-care ultrasound (POCUS) performed by young military medicine residents after short training in the diagnosis of medical emergencies. METHODS: A prospective study was performed in the emergency department of a French army teaching hospital. Two young military medicine residents received ultrasound training focused on gall bladder, kidneys and lower limb veins. After clinical examination, they assigned a 'clinical diagnostic probability' (CP) on a visual analogue scale from 0 (definitely not diagnosis) to 10 (definitive diagnosis). The same student performed ultrasound examination and assigned an 'ultrasound diagnostic probability' (UP) in the same way. The absolute difference between CP and UP was calculated. This result corresponded to the Ultrasound Diagnostic Index (UDI), which was positive if UP was closer to the final diagnosis than CP (POCUS improved the diagnostic accuracy), and negative conversely (POCUS decreased the diagnostic accuracy). RESULTS: Forty-eight patients were included and 48 ultrasound examinations were performed. The present pathologies were found in 14 patients (29%). The mean UDI value was +3 (0-5). UDI was positive in 35 exams (73%), zero in 12 exams (25%) and negative in only one exam (2%). CONCLUSION: POCUS performed after clinical examination increases the diagnostic accuracy of young military medicine residents.

Impact of high-dose norepinephrine during intra-hospital damage control resuscitation of traumatic haemorrhagic shock: A propensity-score analysis.

INTRODUCTION: The use of norepinephrine (NE) during uncontrolled haemorrhagic shock (HS) has mostly been investigated in experimental studies. Clinical data including norepinephrine dose and its impact on fluid resuscitation and organ function are scarce. We hypothesized that there is great variability in NE use and that high doses of NE could lead to increased organ dysfunction as measured by the sequential organ failure assessment (SOFA). METHOD: We included patients with HS (systolic blood pressure < 90 mmHg in severely injured patients) who required haemostasis surgery and a transfusion of more than 4 packed red blood cells (PRBC) in the first 6 h of admission and the used of norepinephrine infusion to maintain the blood pressure goal, between admission and the end of haemostasis surgery in a prospective trauma database. A ROC curve determined that, using Youden's criterion, a dose of NE ≥ 0.6 µg/kg/min was the optimal threshold associated with intrahospital mortality. Patients were compared according to this threshold in a propensity score (PS) model. In a generalized linear mixed model, we searched for independent factors associated with a SOFA ≥ 9 at 24 h RESULTS: A total of 89 patients were analysed. Fluid infusion rate ranged from 1.43 to 57.9 mL/kg/h and norepinephrine infusion rate from 0.1 to 2.8 µg/kg/min. The HDNE group received significantly less fluid than the LDNE group. This dose is associated with a higher SOFA score at 24h: 9 (7-10) vs. 7 (6-9) (p = 0.003). Factors independently associated with a SOFA score ≥ 9 at 24 h were maximal norepinephrine rate ≥ 0.6 µg/kg/min (OR 6.69, 95% CI 1.82 - 25.54; p = 0.004), non-blood resuscitation volume < 9 mL/kg/h (OR 3.98, 95% CI 1.14 - 13.95; p = 0.031) and lactate at admission ≥ 5 mmol/L (OR 5.27, 95% CI 1.48 - 18.77; p = 0.010) CONCLUSION: High dose of norepinephrine infusion is associated with deleterious effects as attested by a higher SOFA score at 24 h and likely hypovolemia as measured by reduced non-blood resuscitation volume. We did not find any significant difference in mortality over the long term.

Cell aggregation enhances bone formation by human mesenchymal stromal cells.

The amount of bone generated using current tissue engineering approaches is insufficient for many clinical applications. Previous in vitro studies suggest that culturing cells as 3D aggregates can enhance their osteogenic potential, but the effect on bone formation in vivo is unknown. Here, we use agarose wells to generate uniformly sized mesenchymal stromal cell (MSC) aggregates. When combined with calcium phosphate ceramic particles and a gel prepared from human platelet-rich plasma, we generated a tissue engineered construct which significantly improved in vivo bone forming capacity as compared to the conventional system of using single cells seeded directly on the ceramic surface. Histology demonstrated the reproducibility of this system, which was tested using cells from four different donors. In vitro studies established that MSC aggregation results in an up-regulation of osteogenic transcripts. And finally, the in vivo performance of the constructs was significantly diminished when unaggregated cells were used, indicating that cell aggregation is a potent trigger of in vivo bone formation by MSCs. Cell aggregation could thus be used to improve bone tissue engineering strategies.

The discovery of Arylex™ active and Rinskor™ active: Two novel auxin herbicides.

Multiple classes of commercially important auxin herbicides have been discovered since the 1940s including the aryloxyacetates (2,4-D, MCPA, dichlorprop, mecoprop, triclopyr, and fluroxypyr), the benzoates (dicamba), the quinoline-2-carboxylates (quinclorac and quinmerac), the pyrimidine-4-carboxylates (aminocyclopyrachlor), and the pyridine-2-carboxylates (picloram, clopyralid, and aminopyralid). In the last 10 years, two novel pyridine-2-carboxylate (or picolinate) herbicides were discovered at Dow AgroSciences. This paper will describe the structure activity relationship study that led to the discovery of the 6-aryl-picolinate herbicides Arylex™ active (2005) and Rinskor™ active (2010). While Arylex was developed primarily for use in cereal crops and Rinskor is still in development primarily for use in rice crops, both herbicides will also be utilized in additional crops.

Emergency ultrasound: a prospective study on sufficient adequate training for military doctors.

PURPOSE: To evaluate the feasibility of "accelerated" training for military doctors in front line ultrasound. To establish the number of ultrasounds required to validate the doctor's training. To assess the average acquisition time for each ultrasound target. MATERIALS AND METHODS: Prospective study on 10 novice generalist military doctors to assess training for five urgent ultrasound targets: focused assessment with sonography in trauma (FAST), pleura, bladder, abdominal aorta and gallbladder. Each student received theoretical and practical training on "healthy" people and then performed 10 timed ultrasounds in an emergency situation, the result of which was either confirmed or rejected by a nationally qualified ultrasound expert. RESULTS: Some targets were easier to acquire (bladder, aorta and pleura) with excellent diagnostic performance after 10 ultrasounds on healthy people (sensitivity = 100%; specificity = 100%). The overall number of ultrasound errors fell over time. The median investigation time also fell significantly for all targets, reaching a plateau. Twenty ultrasounds including 10 "real life" appear to be needed for FAST. A minimum number of 30 ultrasounds is required to diagnose acute cholecystitis. CONCLUSION: "Accelerated" training for generalist military doctors in front line ultrasound is achievable. The recommended number of 25 ultrasounds per target is not appropriate for all ultrasound targets.

Investigation of phosphate adsorption onto ferrihydrite by X-ray photoelectron spectroscopy.

The objective of this study was to characterize phosphate adsorption onto synthetic 2-lines ferrihydrite using surface analysis by X-ray Photoelectron Spectroscopy and batch experiments. Surface analysis of ferrihydrite samples before phosphate sorption gives very reproducible Fe:O surface ratios of (1:3±0.1). Phosphate sorption onto ferrihydrite was investigated by means of pH, initial phosphate concentration, and ionic strength effects. Additionally, potential background electrolyte influence on phosphate adsorption was also determined. Phosphate uptake by ferrihydrite significantly increases with decreasing pH, with a maximum uptake of 104.8 mg PO4 g(-1) obtained at pH=4. Phosphate removal increases with the enhancement of ionic strength in agreement with the formation of inner-sphere complexes. The presence of chloride, nitrate, and sulfate showed no competing effect on phosphate removal efficiency. Sorption kinetics follow a pseudo-second order model (R(2)>0.99) and the Freundlich isotherm model adequately describes sorption (R(2)=0.995). The careful examination of high resolution Fe 2p, O 1s, and P 2p spectra before and after phosphate sorption allows the characterization of the modifications occurring onto the ferrihydrite surface. The binding energy of the P 2p peak agrees well with that observed in Fe-PO4 compounds. Additionally, binding energy shifts in the Fe 2p spectra combined to variations in the relative intensity of the components in the high resolution O 1s spectra illustrate well the formation of chemical bonding between iron and phosphate anions at the ferrihydrite surface.

Heterotopic bone formation by nano-apatite containing poly(D,L-lactide) composites.

To render polymeric materials osteoinductive, nano-sized calcium phosphate apatite particles (CaP) were introduced into a low molecular weight poly(D,L-lactide). Homogenous composites were made with 10%, 20% and 40% by weight of apatite content while pure polylactide was used as control. Thereafter porous samples (pore size 300-400 microm, 60% porosity) were fabricated and sterilized. In vitro studies showed that calcium ions were released from the composites depending on the apatite content, while surface mineral deposition was observed only on the 40% CaP composites in simulated body fluid (SBF) within 14 days. After 12 weeks of intramuscular implantation in dogs, only the 40% CaP composite implant retained its shape and showed ectopic bone formation within the pores. In conclusion, adding a content of 40% apatite into poly(D,L-lactide) could lead to an osteoinductive material. Future studies will focus on understanding this phenomenon of material-directed osteoinduction in order to develop a promising bone graft substitute.

[Serious pulmonary embolism and thromboaspiration]. / Embolie pulmonaire grave et thrombo-aspiration.

Pulmonary embolism is a common disease with a mortality rate of approximately 3%. Polytraumatised patients are particularly susceptible to thromboembolism because of prolonged immobilisation and inflammatory syndrome, thrombembolic risk also increases significantly during the peripartum period. Rapid diagnosis and intervention are essential for survival. Conventional treatment consists of systemic intravascular thrombolysis, but this procedure is often contraindicated in intensive care patients because of the high risk of haemorrhage. We report two cases of successful treatment using radiological endovascular thrombectomy.

[Aortic thrombi associated with thoracic gunshot wound]. / Thrombus aortique compliquant un traumatisme thoracique balistique.

We report the case of a stroke due to a ballistic thoracic traumatism. The vascular injury, provoked by the passage of the bullet, associated to a procoagulating state led to the formation of a thrombus in the ascending aorta. The migration of this thrombus caused a stroke, finally reversible upon medical treatment only.

The Ilizarov external fixator: what remains of the wire pretension after dynamic loading?

BACKGROUND: Maintenance of wire pretension in an Ilizarov external fixator is dependent on the torque applied to the fixation bolts. We therefore measured immediately after surgery the clinically applied torques. The median value was only 10 N m (range 8-14N m). We wondered whether this value is appropriate to maintain the wire pretension and thereby to achieve sufficient fracture stability during dynamic loading of the device for a longer period. METHODS: A material testing machine dynamically loaded one wire mounted on one ring. Several configurations were tested. RESULTS: A quick decrease in wire tension to a steady state situation was seen. In the most stable configuration (20 N m wire fixation torque) 50% of the initial 90 kg wire pretension remained after dynamic loading with 200 N. In the least stable configuration (10 N m torque) considerable wire slippage occurred even without loading and no tension remained after loading! No plastic deformation of the wires was observed so loss of wire tension was due to slippage of the wires through the fixation bolts. INTERPRETATION: With the small fixation torques used in clinical practice considerable wire tension is lost even after a few loading cycles. Further research should address the question whether preservation of a higher wire tension during long term loading promotes faster fracture healing.

Viral hepatitis in minority America.

Viral hepatitis continues as an important public health concern in the United States. Available data indicate that acute and chronic viral hepatitis remains an important cause of morbidity and mortality in this country despite the availability of immunization for hepatitis A and B and pharmacologic therapy for chronic hepatitis B and C. Minority populations within the United States are disproportionately affected by acute and chronic viral hepatitis. Many diseases, for example, Barrett's esophagus, affect ethnic groups differently. Viral hepatitis A, B, and C may demonstrate ethnic variation with regard to their epidemiology, natural history, clinicopatholgic findings, complications, and treatment outcomes. This report will review the literature regarding these areas in hepatitis A, B, and C among the African American, Hispanic American, and Native American populations of the United States.

Effect of maternal low-protein diet and taurine on the vulnerability of adult Wistar rat islets to cytokines.

AIMS/HYPOTHESIS: A maternal low-protein diet has been shown to induce an increased susceptibility of fetal islets to cytokines, but this effect can be avoided by maternal taurine supplementation. Here, we question whether these effects persist until adulthood in the offspring, despite the animal having a normal diet after weaning. METHODS: Pregnant Wistar rats received a diet of either 20% or 8% protein (control [C group] and recuperated [R group] respectively), which was or was not supplemented with taurine (control treated with taurine [CT group] and recuperated treated with taurine [RT group] respectively) during gestation and lactation. When the female offspring reached adulthood, an OGTT was performed. In a second stage, islets were isolated from these offspring, then pretreated or not with taurine, and subsequently treated with cytokines. RESULTS: Fasting glycaemia was higher (p<0.05) and insulinaemia was lower (p<0.01) in the R group than in the C group. Taurine supplementation decreased insulinaemia in the CT group and tended to increase it in the RT group. After the OGTT, glycaemia in R animals was not different from that in the C group, despite a blunted insulin response (p<0.05) which was restored by taurine. Supplementation in C-group mothers led to a weak glucose intolerance. In vitro, more apoptotic cells were observed in R islets after cytokines treatment (p<0.01). The addition of taurine to the culture medium in the R and C groups protected the islets from the cytokines (p<0.01). Maternal taurine supplementation decreased the sensitivity of islets in the RT group (p<0.01), but increased sensitivity in the CT group (p<0.01). CONCLUSIONS/INTERPRETATION: The increased vulnerability of islets to cytokines due to a restriction of protein during fetal development was still evident when the offspring reached adulthood. The low-protein diet also induced hyperglycaemia in the presence of lower insulinaemia. Taurine supplementation protected adult islets of the R group from cytokine toxicity and restored the insulinaemia. However, unnecessary supplementation of taurine could have detrimental effects.

[Glaucoma screening in Martinique. Results in 813 hospital employees]. / Dépistage du glaucome en Martinique: résultats au sein d'une population de 813 salariés hospitaliers.

INTRODUCTION: Several US and Jamaican studies have shown that glaucoma is more severe in black populations than in Caucasian populations, which would lead to the assumption that the people of Martinique have a high glaucoma risk. METHODS: A prospective study was conducted in workers of Fort de France University Hospital with the occupational medicine unit. Intraocular pressure was measured with a pulse air tonometer (Topcon CT 60) and visual field abnormalities were detected with automated perimetry using Humphrey frequency doubling technology (FDT). Patients with known glaucoma or with intraocular pressure over 21 mmHg and/or a visual field abnormality were referred to ophthalmology examination to diagnose ocular hypertension, open-angle glaucoma or normal-pressure glaucoma. RESULTS: The occupational medicine unit examined 813 workers. The sex ratio was 0.36, mean age was 45.35+/-8.4 years (22-64 years), and mean ocular pressure was 12.1+/-2.62 mmHg (6-28 mmHg). Roughly 20% of workers had a family history of glaucoma. We found 22 patients with glaucoma (2.7%) (CI95: 1.6%-4%): 12 patients had open-angle glaucoma (1.5%) and 10 patients were diagnosed with normal-pressure glaucoma (1.3%). Glaucoma prevalence increased with age, reaching 8% in patients over 55 years of age. Of patients with normal-pressure glaucoma, 42.9% had a family history of glaucoma. CONCLUSION: Our results confirm previous data from the literature that found higher glaucoma prevalence in black people and in particular in the mixed-race population of Martinique. In addition to this ethnic feature, the insularity of Martinique could support glaucoma expression. Easy and fast to use, FDT associated with the pulse air tonometer provides early detection of glaucoma.

Small Bowel Lymphoma.

Treatment of small bowel lymphoma requires the expertise of medical and surgical subspecialists. The two most important factors that determine the optimal treatment are histology and staging of small bowel lymphoma. Other factors that may affect treatment include age, multiple areas of involvement, tumor size, and perforation. At present, the best treatment for gastrointestinal lymphoma (stage IE disease) is limited resection of the tumor, followed by postoperative radiotherapy. The cure rate is approximately 75% for stage IE patients, even for those with aggressive histologic types. Chemotherapy is reserved for advanced-staged tumors. In patients with regional nodal involvement or extranodal involvement confined to one side of the diaphragm (pathologic stage IIE disease), chemotherapy should be combined with radiation therapy. The best chemotherapy regimen depends on the histology of the tumor. For diffuse large B-cell lymphoma, the most frequently diagnosed subtype of non-Hodgkin's lymphoma (NHL), the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone) is still the gold standard. Clinical trials have been conducted evaluating the new monoclonal antibody rituximab, along with the CHOP regimen for primary NHL. Results have been promising. The use of rituximab in the treatment of extranodal lymphoma is still being evaluated. Low-grade lymphomas have a more indolent course and do not respond as well to combination chemotherapy agents as the high-grade tumors. Fludarabine alone or in combination with cyclophosphamide is effective as a first-line agent for patients with low-grade NHL. It has also been used to treat relapsed or refractory low-grade NHL. Some promising results have been reported using the chemoimmunotherapy agent rituximab alone or in combination with fludarabine for the treatment of low-grade NHL. However, clinical trials are still needed. In patients with nodal involvement on both sides of the diaphragm or other extranodal involvement such as bone marrow or liver (pathologic stages IIIE and IVE), the disease is managed primarily with combination chemotherapy. Radiation therapy is reserved for treatment of initially bulky tumor sites, treatment of residual disease following chemotherapy, or serious local problems. The disease can be controlled in 25% to 40% of patients with stage IIIE or IVE disease. As with stage IIE disease, the optimal chemotherapy regimen depends on the histologic subtype of NHL.

A human immunodeficiency virus Env inducible transcription system to examine consequences of gp120 expression.

According to several studies, the HIV-1 envelope gp120 protein and the co-receptor CXCR4 play an essential role in HIV-1 induced cell toxicity. Characterisation of the CD4-independent m7NDK isolate provided the opportunity of studying the effects of direct interactions between m7NDK gp120 and CXCR4. Therefore, an inducible expression system was designed enabling synthesis of HIV-1 Env proteins upon doxycycline induction. Analysis of the expression of the env gene of the m7NDK HIV-1 isolate revealed, unexpectedly, that even long-term expression of m7NDK gp120 did not result in cytotoxycity in CXCR4-positive or -negative cell lines. This is the first report of a CD4-independent HIV-1-protein inducible expression regulated through the Tet-On system and by an alternative splicing. Env inducible expression cell lines could constitute a useful cellular tool to undertake analysis of HIV Env protein expression.

[Role of radiotherapy in the treatment of cerebral meningiomas]. / Rôle de la radiothérapie dans le traitement des méningiomes cérébraux.

Cerebral meningiomas account for 15-20% of all cerebral tumours. Although seldom malignant, they frequently recur in spite of complete surgery, which remains the cornerstone of the treatment. In order to decrease the probability of local recurrence, radiotherapy has often been recommended in atypical or malignant meningioma as well as in benign meningioma which was incompletely resected. However, this treatment never was the subject of prospective studies, randomized or not. The purpose of this review of the literature was to give a progress report on the results of different published series in the field of methodology as well as in the techniques of radiotherapy. Proposals for a therapeutic choice are made according to this analysis. For grade I or grade II-III meningiomas, limits of gross tumor volume (GTV) include the tumour in place or the residual tumour after surgery; clinical target volume (CTV) limits include gross tumour volume before surgery with a GTV-CTV distance of 1 and 2 cm respectively. Delivered doses are 55 Gy into CTV and 55-60 Gy and 70 Gy into GTV for grade I and grade II-III meningiomas respectively.