Staphylococcus aureus internalization impairs osteoblastic activity and early differentiation process.

Staphylococcus aureus is the most frequent aetiology of bone and joint infections (BJI) and can cause relapsing and chronic infections. One of the main factors involved in the chronicization of staphylococcal BJIs is the internalization of S. aureus into osteoblasts, the bone-forming cells. Previous studies have shown that S. aureus triggers an impairment of osteoblasts function that could contribute to bone loss. However, these studies focused mainly on the extracellular effects of S. aureus. Our study aimed at understanding the intracellular effects of S. aureus on the early osteoblast differentiation process. In our in vitro model of osteoblast lineage infection, we first observed that internalized S. aureus 8325-4 (a reference lab strain) significantly impacted RUNX2 and COL1A1 expression compared to its non-internalized counterpart 8325-4∆fnbAB (with deletion of fnbA and fnbB). Then, in a murine model of osteomyelitis, we reported no significant effect for S. aureus 8325-4 and 8325-4∆fnbAB on bone parameters at 7 days post-infection whereas S. aureus 8325-4 significantly decreased trabecular bone thickness at 14 days post-infection compared to 8325-4∆fnbAB. When challenged with two clinical isogenic strains isolated from initial and relapse phase of the same BJI, significant impairments of bone parameters were observed for both initial and relapse strain, without differences between the two strains. Finally, in our in vitro osteoblast infection model, both clinical strains impacted alkaline phosphatase activity whereas the expression of bone differentiation genes was significantly decreased only after infection with the relapse strain. Globally, we highlighted that S. aureus internalization into osteoblasts is responsible for an impairment of the early differentiation in vitro and that S. aureus impaired bone parameters in vivo in a strain-dependent manner.

Single-port robotic left colectomy: first clinical experience using the SP robot (rSILS).

BACKGROUND: The single-port daVinci robot is a new platform designed to facilitate single-incision surgeries. The objective of this study was to describe the first clinical experience in colorectal surgery using a novel single-port robotic system and report its feasibility and safety. METHODS: After Institutional Review Board approval was obtained and the study was registered with ClinicalTrials.gov, we performed single port robot-assisted left colectomy using the novel daVinci SP surgical system on two patients. The surgeries were completed through a single incision. The multichannel port accommodates a three-dimensional articulating camera and three double-jointed articulating instruments. The primary aim of this study was to report, for the first time in the USA, the technical feasibility of the procedure in the living human. The secondary aim was to report the outcomes including blood loss, number of incisions, number of dockings, docking time of the robot, incision length, operative time, console time, need for additional port and instrumentation, intraoperative complications, morbidity and mortality, time for tolerating diet, bowel function, and discharge. RESULTS: Both surgeries were completed without conversion through a single incision, 4.0 and 4.5 cm in size. Estimated blood loss was less than 60 ml in both cases. The robot was docked two and three times. Mean time to dock was 13 min (range 3-33 min). There were no intraoperative complications, no morbidity or death. Discharges occurred on postoperative days 2 and 3. CONCLUSIONS: Single-port robotic colectomy using the new robot is feasible and can be safely completed. The overall utility and functionality of the SP robot portends wide utilization and expansion of this technique. Careful development and analysis of the procedure outcomes, training, and cost will be necessary to properly advance the field.

The neutrophil-to-lymphocyte ratio predicts major perioperative complications in patients undergoing colorectal surgery.

AIM: The objective of the study was to evaluate the association between the neutrophil-to-lymphocyte ratio (NLR) and the occurrence of perioperative complications in patients undergoing colorectal surgery. METHOD: A retrospective cohort study was conducted of patients who underwent resection for suspected or confirmed colorectal cancer from 2004 to 2012. Patient cohorts with a high vs low NLR were defined by receiver operating characteristic curve analysis. Univariate and multivariate logistic regression was used to determine whether patients with elevated NLR were more likely to suffer perioperative complications. RESULTS: In all, 583 patients were included. A preoperative NLR greater than or equal to 2.3 was significantly associated with a major perioperative complication (OR 2.52, 95% CI 1.26-5.01). On multivariate analysis, a high NLR (OR 2.25, 95% CI 1.12-4.52) and Charlson Comorbidity Index ≥ 3 (OR 4.55, 95% CI 2.17-9.56) were significantly related to major morbidity. No relationships were found between an elevated preoperative NLR and complication type, although there was a trend towards the occurrence of anastomotic leakage. CONCLUSION: Preoperative NLR ≥ 2.3 may be a risk factor for major surgical complications following colorectal resection. Further study is needed to validate this threshold and evaluate the clinical implications of these findings.

Gene screening of Wharton's jelly derived stem cells.

Stem cells are the most powerful candidate for the treatment of various diseases. Suitable stem cell source should be harvested with minimal invasive procedure, found in great quantity, and transplanted with no risk of immune response and tumor formation. Fetal derived stem cells have been introduced as an excellent alternative to adult and embryonic stem cells use, but unfortunately, their degree of "stemness" and molecular characterization is still unclear. Several studies have been performed deciphering whether fetal stem cells meet the needs of regenerative medicine. We believe that a transcriptomic screening of Wharton's jelly stem cells will bring insights on cell population features.

Chitosan/hydroxyapatite hybrid scaffold for bone tissue engineering.

BACKGROUND: To favor regeneration following critical bone defect, a combination of autologous bone graft and biomaterials is currently used. Major drawbacks of such techniques remain the availability of the autologous material and the second surgical site, inducing pain and morbidity. OBJECTIVE: Our aim was to investigate the biocompatibility in vitro of three dimensions hybrid biodegradable scaffolds combining osteoconductive properties of hydroxyapatite and anti-inflammatory properties of chitosan. METHODS: Hybrid scaffolds were characterized by microscopic observations, equilibrium swelling ratio and overtime weight loss measurements. In vitro studies were performed using primary human bone cells cultured for 7, 14 and 21 days. Cell viability, proliferation, morphology and differentiation through alkaline phosphatase (ALP) activity measurement were assessed. RESULTS: Characterization of our scaffolds demonstrated porous, hydrophilic and biodegradable characteristics. In vitro studies showed that these scaffolds have induced slight decrease in cell death and proliferation comparing to the culture plastic substrate control condition, as well as increased short term osteoinductive properties. CONCLUSIONS: In this study, we have provided evidence that our hybrid hydroxyapatite/chitosan scaffolds could be suitable for bone filling.

Posterior mediastinal hematoma after a fall from standing height: a case report.

Posterior Mediastinal Hematomas (PMHs) secondary to a fall from standing height are uncommon, with only one previous case reported in the literature. We describe a case of a 78-year-old male with multiple medical comorbidities, who was transferred to Montreal General Hospital (MGH) with a posterior mediastinal hematoma (PMH) after sustaining a fall from standing height. On initial assessment, the patient was hemodynamically stable and complained of mild chest pain, dyspnea, fatigue, and diaphoresis. The patient's airway was secured via endotracheal intubation fearing impending respiratory compromise secondary to an enlarging PMH. The patient was admitted to ICU where over the next 3 days he was managed conservatively via careful monitoring of his hemodynamic and hematologic indices. Repeat CT scanning indicated reduction in size of the PMH. The patient was discharged on hospital day eight. This case describes the assessment, evaluation, and conservative management of PMH in a complicated patient receiving prior anticoagulation. A review of the literature regarding the epidemiology of PMH and the management of both unstable and stable PMHs is also presented.

Quantitative trait loci underlying gene product variation: a novel perspective for analyzing regulation of genome expression.

A methodology to dissect the genetic architecture of quantitative variation of numerous gene products simultaneously is proposed. For each individual of a segregating progeny, proteins extracted from a given organ are separated using two-dimensional electrophoresis, and their amounts are estimated with a computer-assisted system for spot quantification. Provided a complete genetic map is available, statistical procedures allow determination of the number, effects and chromosomal locations of factors controlling the amounts of individual proteins. This approach was applied to anonymous proteins of etiolated coleoptiles of maize, in an F2 progeny between two distant lines. The genetic map included both restriction fragment length polymorphism and protein markers. Minimum estimates of one to five unlinked regulatory factors were found for 42 of the 72 proteins analyzed, with a large diversity of effects. Dominance and epistasis interactions were involved in the control of 38% and 14% of the 72 proteins, respectively. Such a methodology might help understanding the architecture of regulatory networks and the possible adaptive or phenotypic significance of the polymorphism of the genes involved.

Mapping factors controlling genetic expression.

A methodology relying on two-dimensional (2D) electrophoresis and genetic mapping is proposed to dissect the genetic architecture of the quantitative control of gene products. Seventy-two anonymous polypeptide spots resolved using silver-stained high-resolution 2D gels of maize coleoptile extracts were automatically quantified for every individual of an F2 progeny between distant lines. A complete genetic linkage map, including 70 RFLP and 39 protein markers, allowed us to map Mendelian factors underlying quantitative variation for 42 polypeptides. One to 5 unlinked chromosomal regions were found to affect single polypeptides, 27% of which resulted in more than a doubling of the polypeptide spot intensity. Dominance was observed for half of the factors, with high amount dominant over low amount in most cases, which is consistent with the observation that the relative abundance of proteins in F1 hybrids is in average deviated to the high parental values. Epistatic interactions were shown to be involved in the control of 14% of the proteins. These features contrast sharply with the observations from 20 agromorphological traits measured in the same progeny, where limited substitution and dominance effects, and no epistatic interaction, were found.

Use of a family record in diabetes clinics.

As a result of a two-year study funded by a BDA Diabetes Development Project, data are presented on the usefulness of a family record in paediatric diabetes clinics. There was a poor response to the invitation to try the family record. Examples are given of its potential usefulness but it is acknowledged that it is likely to be more useful if a psychiatrist or psychotherapist is part of the team.

Liaison psychotherapy in a hospital paediatric diabetic clinic.

A psychotherapist joined the medical team of the paediatric diabetic clinic three years ago. After some initial difficulties all agreed there had been appreciable benefits, not only to individual patients but also to the team in their handling of the psychological aspects of diabetes.

[Brain stem AEP in toxic comas. Correlation with brain stem reflexes]. / Etude des PEA du tronc cérébral dans les comas toxiques. Corrélations avec les réflexes du tronc cérébral.

24 deep toxic comas with respiratory assistance were studied by brain-stem reflex and BAEP. Laboratory analysis showed several simultaneous toxics (phenobarbital, benzodiazepines, tricyclic antidepressants...). Three groups of patients were defined: Twelve patients with normal BAEP and with relatively preserved brain-stem reflex (oculocephalic and oculovestibular are often disturbed but photomotor is present). Eleven patients with delayed BAEP and with more disturbed brain-stem reflex (photomotor is missing 3 times). In 2 cases (one of which is mentioned above in group B) brain-stem reflex and BAEP disappear and these patients die. Cerebral anoxia is associated here with toxics. Causes of delayed latencies (group B) are discussed (hypothermia, toxics). BAEP seems important in diagnosis and prognosis of toxic coma.

Influence of environmental factors on the onset of digestive disorders of the weaned piglet.

An ecopathological study was conducted in Brittany (France) in 89 conventional herds in order to identify the main circumstances that permit the onset of weaning disorders. By comparing the different practices in affected and non-affected herds using multidimensional data analysis methods, a combination of 10 variables was found. These variables are considered as predisposing factors and called "risk factors". They are connected and have a cumulative effect. Preparation to weaning (piglets' weights at weaning, feeding level ingested during suckling period) and environmental conditions of reception of the weaned piglet such as housing requirements are needed.