Early Term Effects of rhBMP-2 on Pedicle Screw Fixation in a Sheep Model: Histomorphometric and Biomechanical Analyses

Background: The effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) on pedicle screw pullout force and its potential to improve spinal fixation have not previously been investigated. rhBMP-2 on an absorbable collagen sponge (ACS) carrier was delivered in and around cannulated and fenestrated pedicle screws in a sheep lumbar spine instability model. Two control groups (empty screw and ACS with buffer) were also evaluated. We hypothesized that rhBMP-2 could stimulate bone growth in and around the cannulated and fenestrated pedicle screws to improve early bone purchase. Methods: Eight skeletally mature sheep underwent destabilizing laminectomies at L2–L3 and L4–L5 followed by stabilization with pedicle screw and rod constructs. An ACS carrier was used to deliver 0.15 mg of rhBMP-2 within and around the cannulated and fenestrated titanium pedicle screws. Biomechanics and histomorphometry were used to evaluate the early term results at 6 and 12 postoperative weeks. Results: rhBMP-2 was unable to improve bony purchase of the cannulated and fenestrated pedicle screws compared to both control groups. Although rhBMP-2 groups had pullout forces that were less than both control groups, both rhBMP-2 groups had pullout force values exceeding 2,000 N, which was comparable to previously published results for unmodified pedicle screws. Significant differences in the percentages of bone in peri-screw tissues was not observed amongst the four treatment groups. Microradiography and quantitative histomorphometry showed that at 6 weeks, rhBMP-2 induced peri-screw remodeling regions containing peri-implant bone which was hypodense with respect to surrounding native trabeculae. A moderate correlation between biomechanical pullout variables and histomorphometry data was observed. Conclusions: The design of the cannulated and fenestrated pedicle screw was able to facilitate new bone formation to achieve high pullout forces. However, delivery of rhBMP-2 should be carefully controlled to prevent excessive bone remodeling which could cause early screw loosening

A Study to Compare Major Adverse Cardiac Event in Patient Undergoing PCI with Drug Eluting Stents Vs Bare Metal Stents

This study compared Major Adverse Cardiac Event in patient with Acute Coronary Syndromes undergoing PCI with Drug Eluting Stents Vs Bare Metal Stents. A retrospective, observational study was carried out in an inpatient setting of the private tertiary care hospital. Patients with >18 years, diagnosed for Acute Coronary Syndromes (ACS), required intervention in coronary artery with implantation of Drug Eluting Stents (DES) or Bare Metal Stents (BMS) were recruited in the study. The data had been collected from file or database of the hospital. All subjects were followed for major adverse cardiac event. Result. A total of 202 patients who underwent percutaneous coronary intervention (PCI) were enrolled into DES group (N=101) and BMS group (N=101). All patients were followed up at 1 month, 3 months, 6 months & 12 months for Major Adverse Cardiac Events (MACE). Clinical outcomes during 12 months were compared between DES group & BMS group. There was no significant difference in baseline parameters including demographic, risk factors of ACS, diagnosis, angiographic parameters between both groups. Overall MACE rates were reported non-significantly high in BMS group patients (14.85%) compare to DES group patients (8.91%) (P=0.458). However, DES group had lower rates of death (0.99% vs 1.98%, P=0.57), rate of MI (3.96% vs 4.95% P=0.73), rate of revascularization (1.98% vs 3.96% p=0.42) & rate of sub acute thrombosis (1.98% vs 3.96% P=0.42) and higher rate of bleeding (1.98% vs 0.99% p=0.57) compare to cohort-II. Conclusion. The use of DES in the setting of Acute Coronary Syndrome is associated with lower Major Adverse Cardiac Event (MACE) rate compared to BMS without compromising the overall safety over the course of one-year follow-up. The long-term safety of drug-eluting stents needs to be ascertained in large, randomized trials

Investigation of mass discharge rate and segregation from hopper by discrete element method

Hoppers of different shape and angle are widely used in different industries particularly in handling of solids as storage units and in unit operations, e.g. mixing, tableting, etc. It is a challenge to choose a right hopper to achieve desired flow and insignificant segregation due to difference in material properties. General approach for the selection of optimum hopper for a given unit operation is based on the trial-and-error experimental approach. To address this optimum hopper selection, combined experimental and numerical approach is presented in this study. The objective of this study is to analyze the effect of mixture composition and hopper angle on the flow rate and segregation behavior. The numerical simulation of granular flow out of various conical hoppers was also performed using the discrete element method (DEM). The materials considered include different particle size glass bead particles in different proportions by mass. The experimental study is done to validate the DEM results, particularly, mass flow rate. The results analyzed include temporal development of mass fraction of a given particle size during discharge. In addition, the mass flow rate is also computed. The results indicate that fines percentage in the mixture, ratio of smallest particle size to largest in the mixture, and hopper angle plays significant role in determining the segregation and mass flow rate. The flow pattern found to be influenced by the hopper angle and mean particle size of mixture. The results of discharge rate from DEM are also compared with existing empirical correlations and finite element method based elastoplastic model. The DEM prediction shows a good agreement with the existing correlations for a wide range of hopper angles, and with the experimental data

Transverse sacralization of lumbar vertebrae: prevalence according to Castellvi classification

Background: Sacralization of L5 is a congenital anomaly, in which the lumbar vertebra, mainly its transverse process, gets fused or semi-fused with the sacrum or the ilium or to both. This fusion can occur in one or both sides of the body. Sacralization leads to fusion of the L5 (fifth lumbar vertebra) and S1 (first sacral vertebra) and the inter-vertebral disc between them may be narrow. Sacralization of lumbar vertebra may be asymptomatic but is not always clinically insignificant. While sacralization may not affect at all, it can cause problems in some cases. Sacralization may be at times associated with problems in biomechanics and affect the ways of movement and posture control. Sacralization may also be an important consideration in disc surgeries. This study has been carried out to find out prevalence of sacralisation of transverse process of fifth lumbar vertebrae.Methods: The present study of transverse sacralisation of fifth lumbar vertebra was carried out on 35 randomly selected patients. The sample consisted of patients undergoing CT scan for abdominal complains. Bone window of all patients were evaluated to look for lumbosacral transitional vertebra.Results: The prevalence of transverse sacralization of lumbar vertebra turned out to be 25.7% out of which Castellvi type IIb was found to be most common, accounting for 33.3% cases. 5.7% comprised the group of normal variant (Castellvi’s type I) and 68.6% were normal. Conclusions: It is important to determine lumbosacral transitional vertebra as it can affect spinal movement and put excess stress on the lumbar vertebrae and in between disc. Moreover it can have a bearing on counting of vertebral levels specially during planning of spinal surgey.

Bacteriological analysis of bile in cholecystectomy patients

Background: Cholecystectomy is currently a frequently performed operation. The presence of gallstones within either the gallbladder or biliary tree is associated with the bacterial colonization of the bile. Acute cholangitis spans a continuous clinical spectrum and can progress from a local biliary infection to advanced disease with sepsis and multiple organ dysfunction syndrome. Therefore, it is important to know the microbiological flora of the gallbladder before prophylactic antibiotics are given. Aims & objectives: To evaluate the microbiological profile of bile from gall bladder in patients undergoing cholecystectomy. To determine the appropriate antibiotic for preoperative prophylaxis in cholecystectomy patients based on the microbiological profile of bile.Methods: The study was a prospective study carried out in SSG Hospital. A total of 78 patients undergone cholecystectomy who met the inclusion criteria were included in the study. 3cc bile was aspirated from all patients, this collected bile from gallbladder before cholecystectomy was transported to the laboratory in sterile test-tube. The specimen was evaluated to find out whether it is sterile or has any bacteria present. The types of bacteria are determined and whether the amount of isolate is significant or not. And sensitivity to antibacterial agents against antibiotics was determined.Results: 19 patients showed positive bile culture in which Escherichia coli was the most common isolated bacteria (63.16% among positive bile culture and 15.38% among all patients) and bile was sterile in 59 patients (75.64%). Other organisms isolated were Pseudomonas (3.85%), Klebsiella (2.56%), coagulase negative Staphylococcus and Staphylococcus viridans (1.28%). Positive bile culture was a more common finding (50% of patients were bile culture positive) in patients with acute cholecystitis in this study. Post-operative wound infection is more common (15.79%) in group of patients with isolated organism from bile. There is a strong correlation between bile culture and wound culture (75%).  Conclusions: It was found that sensitivity to third- and fourth-generation cephalosporins was higher as compared to aminoglycoside in acute as well as chronic cholecystitis. In this study levofloxacin also shows good sensitivity against isolated organism from bile. Piperacilin and tazobactum also shows good sensitivity against isolated organism from bile and they are more effective against pseudomonas. The resistance to second-generation cephalosporins and aminoglycoside has increased. For preoperative prophylaxis third and fourth-generation cephalosporins and levofloxacin show better promise and may be used as the first line of preoperative prophylaxis in operations for acute and chronic cholecystitis undergoing cholecystectomy.

Natural history and clinical effect of aortic valve regurgitation after left ventricular assist device implantation

ObjectivesAortic valve regurgitation reduces left ventricular assist device mechanical efficiency. Evidence has also suggested that left ventricular assist device implantation can induce or exacerbate aortic valve regurgitation. However, this has not been compared with aortic valve regurgitation progression in a nonsurgical end-stage heart failure population. Furthermore, its clinical effect is unclear. We sought to characterize the development and progression of aortic valve regurgitation in left ventricular assist device recipients and to identify its clinical effect.MethodsA review of all consecutive patients who received an intracorporeal left ventricular assist device at Duke University Medical Center from January 2004 to January 2011 was conducted. Cases of previous or concomitant aortic valve surgery were excluded. Data from the remaining implants (n = 184) and a control group of contemporaneous nonsurgical patients with end-stage heart failure (n = 132) were analyzed. Serial transthoracic echocardiography was used to characterize aortic valve regurgitation as a function of time.ResultsLeft ventricular assist device implantation was associated with worsening aortic valve regurgitation, defined as an increase in aortic valve regurgitation grade, relative to the nonsurgical patients with end-stage heart failure (P < .0001). The recipients of continuous flow left ventricular assist devices were more likely than recipients of pulsatile left ventricular assist devices to develop worsening aortic valve regurgitation (P = .0348). Moderate or severe aortic valve regurgitation developed in 21 left ventricular assist device recipients; this was unrelated to the type of device implanted (continuous vs pulsatile; P = .754) or aortic valve regurgitation grade before left ventricular assist device implantation (P = .42). Five patients developed severe aortic valve regurgitation; all of whom underwent aortic valve procedures.ConclusionsNative aortic valve regurgitation developed and/or progressed after left ventricular assist device implantation, with this effect being more pronounced in continuous flow left ventricular assist device recipients. However, the preoperative aortic valve regurgitation grade failed to correlate with the development of substantial aortic valve regurgitation after left ventricular assist device implantation. After left ventricular assist device implantation, aortic valve regurgitation had a small, but discernible, clinical effect, with some patients developing severe aortic valve regurgitation and requiring aortic valve procedures. These data have implications for the long-term management of left ventricular assist device recipients, in particular as the durability of implantable continuous flow left ventricular assist device therapy improves

Hemodynamic Predictors of Heart Failure Morbidity and Mortality: Fluid or Flow?

BACKGROUND: Patients with advanced heart failure may persist for prolonged times with persistent hemodynamic abnormalities; intermediate and long-term outcomes of these patients are unknown. METHODS AND RESULTS: We used ESCAPE trial data to examine characteristics and outcomes of patients with invasive hemodynamic monitoring during an acute heart failure hospitalization. Patients were stratified by final measurement of cardiac index (CI; L/min/m2) and pulmonary capillary wedge pressure (PCWP; mmHg) before catheter removal. The study groups were CI ≥ 2/PCWP <20 (n = 74), CI ≥ 2/PCWP ≥ 20 (n = 37), CI < 2/PCWP < 20 (n = 23), and CI < 2/PCWP ≥ 20 (n = 17). Final CI was not associated with the combined risk of death, cardiovascular hospitalization, and transplantation (HR:1.03, 95% CI:0.96–1.11 per 0.2 L/min/m(2) decrease, p=0.39), but final PCWP ≥ 20mmHg was associated with increased risk of these events (HR:2.03, 95% CI:1.31–3.15, p<0.01), as was higher final right atrial pressure (RAP; HR:1.09, 95% CI:1.06–1.12 per mmHg increase, p<0.01). CONCLUSION: Final PCWP and final RAP were stronger predictors of post-discharge outcomes than CI in patients with advanced heart failure. The ability to lower filling pressures appears to be more prognostically important than improving CI in the management of patients with advanced heart failure. CLINICALTRIALS.GOV IDENTIFIER: NCT0000061

The incidence, risk factors, and outcomes associated with late right-sided heart failure in patients supported with an axial-flow left ventricular assist device

BACKGROUND: Early right-sided heart failure (RHF) after left ventricular assist device (LVAD) implantation is associated with increased mortality, but little is known about patients who develop late RHF (LRHF). We evaluated the incidence, risk factors, and clinical impact of LRHF in patients supported by axial-flow LVADs. METHODS: Data were analyzed from 537 patients enrolled in the HeartMate II (HM II; Thoratec/St. Jude) destination therapy clinical trial. LRHF was defined as the development of clinical RHF accompanied by the need for inotropic support occurring more than 30 days after discharge from the index LVAD implant hospitalization. Clinical variables, quality of life, rehospitalizations, and survival were compared between patients with and without LRHF. RESULTS: LRHF developed in 41 patients (8%), with a median time to LRHF of 480 days. A higher preoperative blood urea nitrogen and increased central venous pressure-to-pulmonary capillary wedge pressure ratio were independent predictors of LRHF. The Michigan and HMII RHF risk scores were both associated with an increased likelihood of LRHF (p < 0.05). Patients with LRHF had worse quality of life according to the Kansas City Cardiomyopathy Questionnaire (61 ± 26 vs 70 ± 21; p < 0.05), poorer functional capacity by 6-minute walk distance (275 ± 189 m vs 312 ± 216 m; p < 0.05), and more rehospitalizations (6 vs 3; p < 0.001). LRHF was associated with decreased survival (p < 0.001). CONCLUSIONS: LRHF is an important complication in patients with LVADs and is associated with worse quality of life, reduced functional capacity, more frequent hospitalizations, and worse survival compared with those without LRHF

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London