Multimeric tyrosine sulfate acts as an endothelial cell protectant and prevents complement activation in xenotransplantation models

BACKGROUND: Activation of endothelial cells (EC) in xenotransplantation is mostly induced through binding of antibodies (Ab) and activation of the complement system. Activated EC lose their heparan sulfate proteoglycan (HSPG) layer and exhibit a procoagulant and pro-inflammatory cell surface. We have recently shown that the semi-synthetic proteoglycan analog dextran sulfate (DXS, MW 5000) blocks activation of the complement cascade and acts as an EC-protectant both in vitro and in vivo. However, DXS is a strong anticoagulant and systemic use of this substance in a clinical setting might therefore be compromised. It was the aim of this study to investigate a novel, fully synthetic EC-protectant with reduced inhibition of the coagulation system. METHOD: By screening with standard complement (CH50) and coagulation assays (activated partial thromboplastin time, aPTT), a conjugate of tyrosine sulfate to a polymer-backbone (sTyr-PAA) was identified as a candidate EC-protectant. The pathway-specificity of complement inhibition by sTyr-PAA was tested in hemolytic assays. To further characterize the substance, the effects of sTyr-PAA and DXS on complement deposition on pig cells were compared by flow cytometry and cytotoxicity assays. Using fluorescein-labeled sTyr-PAA (sTyr-PAA-Fluo), the binding of sTyr-PAA to cell surfaces was also investigated. RESULTS: Of all tested compounds, sTyr-PAA was the most effective substance in inhibiting all three pathways of complement activation. Its capacity to inhibit the coagulation cascade was significantly reduced as compared with DXS. sTyr-PAA also dose-dependently inhibited deposition of human complement on pig cells and this inhibition correlated with the binding of sTyr-PAA to the cells. Moreover, we were able to demonstrate that sTyr-PAA binds preferentially and dose-dependently to damaged EC. CONCLUSIONS: We could show that sTyr-PAA acts as an EC-protectant by binding to the cells and protecting them from complement-mediated damage. It has less effect on the coagulation system than DXS and may therefore have potential for in vivo application.

Postpartum osteoporosis associated with proximal tibial stress fracture

A 33-year-old woman presented with acute nonspecific knee pain, 6 months postpartum. MR imaging, computed tomography and radiography were performed and a proximal tibia plateau insufficiency fracture was detected. Bone densitometry demonstrated mild postpartum osteoporosis. To our knowledge these findings have not been described in this location and in this clinical setting. The etiology of the atraumatic fracture of the tibia is presumed to be due to a low bone mineral density. The bone loss was probably due to pregnancy, lactation and postpartum hormonal changes. There were no other inciting causes and the patient was normocalcemic. We discuss the presence of a postpartum stress fracture in a hitherto undescribed site in a patient who had lactated following an uncomplicated pregnancy and had no other identifiable cause for a stress fracture.

Cement-augmented anterior screw fixation of Type II odontoid fractures in elderly patients with osteoporosis

BACKGROUND CONTEXT: Closed reduction and internal fixation by an anterior approach is an established option for operative treatment of displaced Type II odontoid fractures. In elderly patients, however, inadequate screw purchase in osteoporotic bone can result in severe procedure-related complications. PURPOSE: To improve the stability of odontoid fracture screw fixation in the elderly using a new technique that includes injection of polymethylmethacrylat (PMMA) cement into the C2 body. STUDY DESIGN: Retrospective review of hospital and outpatient records as well as radiographs of elderly patients treated in a university hospital department of orthopedic surgery. PATIENT SAMPLE: Twenty-four elderly patients (8 males and 16 females; mean age, 81 years; range, 62-98 years) with Type II fractures of the dens. OUTCOME MEASURES: Complications, cement leakage (symptomatic/asymptomatic), operation time, loss of reduction, pseudarthrosis and revision surgery, patient complaints, return to normal activities, and signs of neurologic complications were all documented. METHODS: After closed reduction and anterior approach to the inferior border of C2, a guide wire is advanced to the tip of the odontoid under biplanar fluoroscopic control. Before the insertion of one cannulated, self-drilling, short thread screws, a 12 gauge Yamshidi cannula is inserted from anterior and 1 to 3 mL of high-viscosity PMMA cement is injected into the anteroinferior portion of the C2 body. During polymerization of the cement, the screws are further inserted using a lag-screw compression technique. The cervical spine then is immobilized with a soft collar for 8 weeks postoperatively. RESULTS: Anatomical reduction of the dens was achieved in all 24 patients. Mean operative time was 64 minutes (40-90 minutes). Early loss of reduction occurred in three patients, but revision surgery was indicated in only one patient 2 days after primary surgery. One patient died within the first eight postoperative weeks, one within 3 months after surgery. In five patients, asymptomatic cement leakage was observed (into the C1-C2 joint in three patients, into the fracture in two). Conventional radiologic follow-up at 2 and 6 months confirmed anatomical healing in 16 of the19 patients with complete follow-up. In two patients, the fractures healed in slight dorsal angulation; one patient developed a asymptomatic pseudarthrosis. All patients were able to resume their pretrauma level of activity. CONCLUSIONS: Cement augmentation of the screw in Type II odontoid fractures in elderly patients is technically feasible in a clinical setting with a low complication rate. This technique may improve screw purchase, especially in the osteoporotic C2 body.

Effect of mannitol dry powder challenge on exhaled nitric oxide in children

BACKGROUND Fractional exhaled nitric oxide (FENO), a non-invasive marker of eosinophilic airway inflammation, is increasingly used for diagnostic and therapeutic decisions in adult and paediatric asthma. Standardized guidelines for the measurement of FENO recommend performing FENO measurements before rather than after bronchial provocation tests. OBJECTIVE To investigate whether FENO levels decrease after a Mannitol dry powder (MDP) challenge in a clinical setting, and whether the extent of the decrease is influenced by number of MDP manoeuvres, baseline FENO, atopy and doctor diagnosed asthma. METHODS Children aged 6-16 years, referred for possible reactive airway disease to a respiratory outpatient clinic, performed an MDP challenge (Aridol®, Pharmaxis, Australia). FENO was measured in doublets immediately before and after the challenge test using the portable NIOX MINO® device (Aerocrine, Stockholm, Sweden). We analysed the data using Kruskal-Wallis rank tests, Wilcoxon signed rank tests and multivariable linear regressions. RESULTS One hundred and seven children completed both tests (mean±SD age 11.5±2.8 years). Overall, median (interquartile range) FENO decreased slightly by -2.5 ppb (-7.0, -0.5), from 18.5 ppb (10.5, 45.5) before the MDP challenge to 16.5 ppb thereafter (8.5, 40.5; p<0.001). In all participants, the change in FENO was smaller than one standard deviation of the baseline mean. The % fall in FENO was smaller in children with less MDP manoeuvres (e.g. higher bronchial responsiveness; p = 0.08) but was not influenced by levels of baseline FENO (p = 0.68), atopy (p = 0.84) or doctor diagnosed asthma (p = 0.93). CONCLUSION MDP challenge test influences FENO values but differences are small and clinically barely relevant.

Limitations of the use of pressure waves to verify correct epidural needle position in dogs

The use of pressure waves to confirm the correct position of the epidural needle has been described in several domestic species and proposed as a valid alternative to standard methods, namely, control radiographic exam and fluoroscopy. The object of this retrospective clinical study was to evaluate the sensitivity of the epidural pressure waves as a test to verify the correct needle placement in the epidural space in dogs, in order to determine whether this technique could be useful not only in the clinical setting but also when certain knowledge of needle's tip position is required, for instance when performing clinical research focusing on epidural anaesthesia. Of the 54 client-owned dogs undergoing elective surgeries and enrolled in this retrospective study, only 45% showed epidural pressure waves before and after epidural injection. Twenty-six percent of the animals showed epidural pressure waves only after the injection, whereas 29% of the dogs showed epidural pressure waves neither before nor after injection and were defined as false negatives. Our results show that the epidural pressure wave technique to verify epidural needle position lacks sensitivity, resulting in many false negatives. As a consequence, the applicability of this technique is limited to situations in which precise, exact knowledge of the needle's tip position is not mandatory.

Virologic and immunologic responses in treatment-naive patients to ritonavir-boosted atazanavir or efavirenz with a common backbone

Background: Atazanavir boosted with ritonavir (ATV/r) and efavirenz (EFV) are both recommended as first-line therapies for HIV-infected patients. We compared the 2 therapies for virologic efficacy and immune recovery. Methods: We included all treatment-naïve patients in the Swiss HIV Cohort Study starting therapy after May 2003 with either ATV/r or EFV and a backbone of tenofovir and either emtricitabine or lamivudine. We used Cox models to assess time to virologic failure and repeated measures models to assess the change in CD4 cell counts over time. All models were fit as marginal structural models using both point of treatment and censoring weights. Intent-to-treat and various as-treated analyses were carried out: In the latter, patients were censored at their last recorded measurement if they changed therapy or if they were no longer adherent to therapy. Results: Patients starting EFV (n = 1,097) and ATV/r (n = 384) were followed for a median of 35 and 37 months, respectively. During follow-up, 51% patients on EFV and 33% patients on ATV/r remained adherent and made no change to their first-line therapy. Although intent-to-treat analyses suggest virologic failure was more likely with ATV/r, there was no evidence for this disadvantage in patients who adhered to first-line therapy. Patients starting ATV/r had a greater increase in CD4 cell count during the first year of therapy, but this advantage disappeared after one year. Conclusions: In this observational study, there was no good evidence of any intrinsic advantage for one therapy over the other, consistent with earlier clinical trials. Differences between therapies may arise in a clinical setting because of differences in adherence to therapy.

Organ donation in Switzerland - an analysis of factors associated with consent rate

BACKGROUND AND AIM Switzerland has a low post mortem organ donation rate. Here we examine variables that are associated with the consent of the deceased's next of kin (NOK) for organ donation, which is a prerequisite for donation in Switzerland. METHODS AND ANALYSIS During one year, we registered information from NOK of all deceased patients in Swiss intensive care units, who were approached for consent to organ donation. We collected data on patient demographics, characteristics of NOK, factors related to the request process and to the clinical setting. We analyzed the association of collected predictors with consent rate using univariable logistic regression models; predictors with p-values <0.2 were selected for a multivariable logistic regression. RESULTS Of 266 NOK approached for consent, consent was given in 137 (51.5%) cases. In multivariable analysis, we found associations of consent rates with Swiss nationality (OR 3.09, 95% CI: 1.46-6.54) and German language area (OR 0.31, 95% CI: 0.14-0.73). Consent rates tended to be higher if a parent was present during the request (OR 1.76, 95% CI: 0.93-3.33) and if the request was done before brain death was formally declared (OR 1.87, 95% CI: 0.90-3.87). CONCLUSION Establishing an atmosphere of trust between the medical staff putting forward a request and the NOK, allowing sufficient time for the NOK to consider donation, and respecting personal values and cultural differences, could be of importance for increasing donation rates. Additional measures are needed to address the pronounced differences in consent rates between language regions.

Etomidate for critically ill patients. Con: do you really want to weaken the frail?

Etomidate is an imidazole-derived hypnotic agent preferentially used for rapid sequence induction of anaesthesia because of its favourable haemodynamic profile. However, 11β-hydroxylase inhibition causes adrenal insufficiency with potentially fatal consequences in specific populations. We review the arguments against the liberal administration of etomidate in critically ill, and especially septic, patients. This review considered only high-quality and prospective studies with a low risk of bias. Three major effects have been observed with the clinical use of a single dose of etomidate. First, independent of the clinical setting, etomidate causes adrenal dysfunction via 11β-hydroxylase inhibition ranging from 12 to 48 h, making the drug unsuitable for use in elective interventions. Second, in a systematic review with meta-analyses, including 3715 septic patients, the relative risk of death with etomidate was 1.22 (95% confidence interval 1.11 to 1.35). Based on this statistically significant and clinically relevant increase in mortality, a single dose of etomidate has to be avoided in patients with septic shock. Third, in small randomised controlled trials, a single dose of etomidate in trauma patients was associated with an increased incidence of pneumonia (56.7 vs. 25.9% in controls), prolonged intensive care stay (6.3 vs. 1.5 days) and prolonged hospital stay (11.6 vs. 6.4 days). Based on these randomised controlled trials, the use of etomidate should be avoided in unstable trauma patients. Midazolam and ketamine are two valid alternatives with similar intubation and haemodynamic conditions as etomidate but without its adverse effects. Therefore, for safety reasons, etomidate should be avoided in the critical conditions of sepsis and trauma

Engraftment of autologous bone marrow cells into the injured cranial cruciate ligament in dogs

Current research indicates that exogenous stem cells may accelerate reparative processes in joint disease but, no previous studies have evaluated whether bone marrow cells (BMCs) target the injured cranial cruciate ligament (CCL) in dogs. The objective of this study was to investigate engraftment of BMCs following intra-articular injection in dogs with spontaneous CCL injury. Autologous PKH26-labelled BMCs were injected into the stifle joint of eight client-owned dogs with CCL rupture. The effects of PKH26 staining on cell viability and PKH26 fluorescence intensity were analysed in vitro using a MTT assay and flow cytometry. Labelled BMCs in injured CCL tissue were identified using fluorescence microscopy of biopsies harvested 3 and 13 days after intra-articular BMC injection. The intensity of PKH26 fluorescence declines with cell division but was still detectable after 16 days. Labelling with PKH26 had no detectable effect on cell viability or proliferation. Only rare PKH26-positive cells were present in biopsies of the injured CCL in 3/7 dogs and in synovial fluid in 1/7 dogs. No differences in transforming growth factor-beta1, and interleukin-6 before and after BMC treatment were found and no clinical complications were noted during a 1 year follow-up period. In conclusion, BMCs were shown to engraft to the injured CCL in dogs when injected into the articular cavity. Intra-articular application of PKH26-labelled cultured mesenchymal stem cells is likely to result in higher numbers of engrafted cells that can be tracked using this method in a clinical setting.

Technical complications and failures of zirconia-based prostheses supported by implants followed up to 7 years: a case series.

PURPOSE To evaluate technical complications and failures of zirconia-based fixed prostheses supported by implants. MATERIALS AND METHODS Consecutive patients received zirconia-based single crowns (SCs) and fixed dental prostheses (FDPs) on implants in a private clinical setting between 2005 and 2010. One dentist performed all surgical and prosthetic procedures, and one master technician performed and coordinated all laboratory procedures. One-piece computer-aided design/ computer-assisted manufacture technology was used to fabricate abutments and frameworks, which were directly connected at the implant level, where possible. All patients were involved in a recall maintenance program and were finally reviewed in 2012. Data on framework fractures, chipping of veneering ceramics, and other technical complications were recorded. The primary endpoint was failure of the prostheses, ie, the need for a complete remake. A life table analysis was calculated. RESULTS A total of 289 implants supported 193 zirconia-based prostheses (120 SCs and 73 FDPs) in 127 patients (51 men, 76 women; average age: 62.5 ± 13.4 years) who were reviewed in 2012. Twenty-five (13%) prostheses were cemented on 44 zirconia abutments and 168 (87%) prostheses were screw-retained directly at the implant level. Fracture of 3 frameworks (1 SC, 2 FDPs) was recorded, and significant chipping resulted in the remake of 3 prostheses (1 SC, 2 FDPs). The 7-year cumulative survival rate was 96.4% ± 1.99%. Minor complications comprised 5 loose screws (these were retightened), small chips associated with 3 prostheses (these were polished), and dislodgement of 3 prostheses (these were recemented). Overall, 176 prostheses remained free of technical problems. CONCLUSIONS Zirconia-based prostheses screwed directly to implants are clinically successful in the short and medium term.

The impact of loupes and microscopes on vision in endodontics.

AIM To report on an intraradicular visual test in a simulated clinical setting under different optical conditions. METHODOLOGY Miniaturized visual tests with E-optotypes (bar distance from 0.01 to 0.05 mm) were fixed inside the root canal system of an extracted maxillary molar at different locations: at the orifice, a depth of 5 mm and the apex. The tooth was mounted in a phantom head for a simulated clinical setting. Unaided vision was compared with Galilean loupes (2.5× magnification) with integrated light source and an operating microscope (6× magnification). The influence of the dentists' age within two groups was evaluated: <40 years (n = 9) and ≥40 years (n = 15). RESULTS Some younger dentists were able to identify the E-optotypes at the orifice, but otherwise, natural vision did not reveal any measurable result. With Galilean loupes, the younger dentists <40 years could see a 0.05 mm structure at the root canal orifice, in contrast to the older group ≥40 years. Only the microscope allowed the observation of structures inside the root canal, independent of age. CONCLUSION Unaided vision and Galilean loupes with an integrated light source could not provide any measurable vision inside the root canal, but younger dentists <40 years could detect with Galilean loupes a canal orifice corresponding to the tip of the smallest endodontic instruments. Dentists over 40 years of age were dependent on the microscope to inspect the root canal system.

MicroRNA profile of poorly differentiated thyroid carcinomas: new diagnostic and prognostic insights.

The diagnosis of conventional and oncocytic poorly differentiated (oPD) thyroid carcinomas is difficult. The aim of this study is to characterise their largely unknown miRNA expression profile and to compare it with well-differentiated thyroid tumours, as well as to identify miRNAs which could potentially serve as diagnostic and prognostic markers. A total of 14 poorly differentiated (PD), 13 oPD, 72 well-differentiated thyroid carcinomas and eight normal thyroid specimens were studied for the expression of 768 miRNAs using PCR-Microarrays. MiRNA expression was different between PD and oPD thyroid carcinomas, demonstrating individual clusters on the clustering analysis. Both tumour types showed upregulation of miR-125a-5p, -15a-3p, -182, -183-3p, -222, -222-5p, and downregulation of miR-130b, -139-5p, -150, -193a-5p, -219-5p, -23b, -451, -455-3p and of miR-886-3p as compared with normal thyroid tissue. In addition, the oPD thyroid carcinomas demonstrated upregulation of miR-221 and miR-885-5p. The difference in expression was also observed between miRNA expression in PD and well-differentiated tumours. The CHAID algorithm allowed the separation of PD from well-differentiated thyroid carcinomas with 73-79% accuracy using miR-23b and miR-150 as a separator. Kaplan-Meier and multivariate analysis showed a significant association with tumour relapses (for miR-23b) and with tumour-specific death (for miR-150) in PD and oPD thyroid carcinomas. MiRNA expression is different in conventional and oPD thyroid carcinomas in comparison with well-differentiated thyroid cancers and can be used for discrimination between these tumour types. The newly identified deregulated miRNAs (miR-150, miR-23b) bear the potential to be used in a clinical setting, delivering prognostic and diagnostic informations.

Glomerular filtration rate, urine production, and fractional clearance of electrolytes in acute kidney injury in dogs and their association with survival.

BACKGROUND Acute kidney injury (AKI) is common in dogs. Few studies have assessed sequential changes in indices of kidney function in dogs with naturally occurring AKI. OBJECTIVE To document sequential changes of conventional indices of renal function, to better define the course of AKI, and to identify a candidate marker for recovery. ANIMALS Ten dogs with AKI. METHODS Dogs were prospectively enrolled and divided into surviving and nonsurviving dogs. Urine production was measured with a closed system for 7 days. One and 24-hour urinary clearances were performed daily to estimate solute excretion and glomerular filtration rate (GFR). Solute excretion was calculated as an excretion ratio (ER) and fractional clearance (FC) based on both the 1- and 24-hour urine collections. RESULTS Four dogs survived and 6 died. At presentation, GFR was not significantly different between the outcome groups, but significantly (P = .03) increased over time in the surviving, but not in the nonsurviving dogs. Fractional clearance of Na decreased significantly over time (20.2-9.4%, P < .0001) in the surviving, but not in the nonsurviving dogs. The ER and FC of solutes were highly correlated (r, 0.70-0.95). CONCLUSION AND CLINICAL IMPACT Excretion ratio might be used in the clinical setting as a surrogate marker to follow trends in solute excretion. Increased GFR, urine production, and decreased FC of Na were markers of renal recovery. The FC of Na is a simple, noninvasive, and cost-effective method that can be used to evaluate recovery of renal function.

Which Radiographic Hip Parameters Do Not Have to Be Corrected for Pelvic Rotation and Tilt?

Background Acetabular anatomy on AP pelvic radiographsdepends on pelvic orientation during radiograph acquisition. However, not all parameters may change to a clinically relevant degree with differences in pelvic orientation. This issue may influence the diagnosis of acetabular pathologies and planning of corrective acetabular surgery (reorientation or rim trimming). However, to this point, it has not been well characterized. Questions/purposes We asked (1) which radiographic parameters change in a clinical setting when normalized to neutral pelvic orientation; (2) which parameters do not change in an experimental setting when the pelvis is experimentally rotated/tilted; and (3) which of these changes are ‘‘ultimately’’ relevant based on a prespecified definition of relevance. Methods In a clinical setup, 11 hip parameters were evaluated in 101 patients (126 hips) by two observers and the interobserver difference was calculated. All parameters were normalized to an anatomically defined neutral pelvic orientation with the help of a lateral pelvic radiograph and specific software. Differences between nonnormalized and normalized values were calculated (effect of normalization). In an experimental setup involving 20 cadaver pelves (40 hips), the maximum range for each parameter was computed with the pelvis rotated (range, −12° to 12°) and tilted (range, −24° to 24°). ‘‘Ultimately’’ relevant changes existed if the effect of normalization exceeded the interobserver difference (eg, 37% versus 6% for prevalence of a positive crossover sign) and/or the maximum experimental range exceeded 1 SD of interobserver difference (eg, 27% versus 6% for anterior acetabular coverage). Results In the clinical setup, all parameters except the ACM angle and craniocaudal acetabular coverage changed when being normalized, eg, effect of normalization for lateral center-edge angle, acetabular index, and sharp angle ranged from −5° to 4° (p values < 0.029). In the experimental setup, five parameters showed no major changes, whereas six parameters did change (all p values < 0.001). Ultimately relevant changes were found for anteroposterior acetabular coverage, retroversion index, and prevalence of a positive crossover or posterior wall sign. Conclusions Lateral center-edge angle, ACM angle, Sharp angle, acetabular and extrusion index, and craniocaudal acetabular coverage showed no relevant changes with varying pelvic orientation and can therefore be acquired independent from individual pelvic tilt and rotation in clinical practice. In contrast, anteroposterior acetabular coverage, crossover and posterior wall sign, and retroversion index call for specific efforts that address individual pelvic orientation such as computer-assisted evaluation of radiographs. Level of Evidence Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

The role of self-monitoring of blood glucose in patients treated with SGLT-2 inhibitors: a European expert recommendation.

The role for the novel treatment approach of sodium-glucose cotransporter-2 (SGLT-2) in type 2 diabetes is increasing. Structured self-monitoring of blood glucose (SMBG), based on a less intensive and a more intensive scheme, may contribute to an optimization of SGLT-2 inhibitor based treatment. The current expert recommendation suggests individualized approaches of SMBG, using simple and clinically applicable schemes. Potential benefits of SMBG in SGLT-2 inhibitor based treatment approaches are early assessment of treatment success or failure, timely modification of treatment, detection of hypoglycemic episodes, assessment of glucose excursions, and support of diabetes management and education. The length and frequency of SMBG should depend on the clinical setting and the quality of metabolic control.