Evaluation of stress patterns generated by reduction forceps within a photoelastic mandibular model.

INTRODUCTION: Little attention has been paid to the mechanical effects of fracture reduction forceps. AIM: This study aims to evaluate the stress patterns within the fractured mandible generated by reduction forceps. MATERIAL AND METHODS: Thirty-six mandibular models were fabricated using a photoelastic resin. Each of the three sets of mandibular models was osteotomized according to one of three different fracture types. After reducing the cut segments, reduction forceps were placed into different engagement holes to compress the segments. Photoelastic stress analysis was used to visualize the stress patterns within the fractured mandibular models as generated by the reduction forceps. RESULTS: In the case of symphyseal or parasymphyseal fractures, an optimum distribution of stresses over the fracture site was achieved when placing the reduction forceps more than 12mm away from either side of the fracture line, between the midway level of the mandibular height (bisecting the mandible) and 5mm below this level. In the case of body fractures, optimum stress distribution was achieved when the reduction forceps were placed more than 16mm from the fracture line at the midway level. CONCLUSION: Correct use of the reduction forceps helps to provide a precise three-dimensional reduction for mandibular fractures.     

Ceramic on ceramic hip arthroplasty in fused hips

Background:Most literature in the field of total hip arthroplasty (THA) for fused hips, until date has reported the results of using metal on polyethylene and ceramic on polyethylene bearings. Results of THA using ceramic on ceramic (CoC) bearings in fused hips have not been published in literature. This study reports the results of cementless THA using CoC articulation perfomed in fused hips.Results:Mean Harris hip score improved from 42.4 to 84.2 and mean leg lengthening of 36.6 mm was achieved. In the average 5.4 years (range 2.8-9.1 years) followup there were no cases with osteolysis around acetabular cup and femoral stem. In this study, there was no case of ceramic fracture. There was one case of squeaking.Conclusion:This study suggests that cementless THA performed for fused hips with CoC bearings can provide good early clinical results.     

Recurrent genomic alterations with impact on survival in colorectal cancer identified by genome-wide array comparative genomic hybridization

BACKGROUND & AIMS: Although genetic aspects of tumorigenesis in colorectal cancer (CRC) have been well studied, reliable biomarkers predicting prognosis are scarce. We aimed to identify recurrently altered genomic regions (RAR) in CRC with high resolution, to investigate their implications on survival and to explore novel cancer-related genes in prognosis-associated RARs. METHODS: A 1-Mb resolution microarray-based comparative genomic hybridization (array CGH) was applied to 59 CRCs. RARs, defined as genomic alterations, detected in more than 10 cases were identified and analyzed for their association with survival. Expression levels of genes in prognosis-associated RARs were examined by real-time quantitative polymerase chain reaction. RESULTS: Twenty-seven RARs were identified. Eleven high-level amplifications and 2 homozygous deletions also were detected, but they were not as common as RARs. Multivariate analysis revealed RAR-L1 (loss on 1p36; hazard ratio = 8.15, P = .002) and RAR-L20 (loss on 21q22; hazard ratio = 3.53, P = .034) are independent indicators of poor prognosis. Expression of CAMTA1, located in RAR-L1, was reduced frequently in CRCs, and low CAMTA1 expression was associated significantly with poor prognosis, which indicates that CAMTA1 may play a role as a tumor suppressor in CRC. Five pairs of RARs were correlated significantly to each other and 3 pairs share genes involved in the same biological functions, suggesting possible collaborative roles in tumorigenesis. CONCLUSIONS: We identified recurrent genomic changes in 59 CRCs. RARs could be more important in sporadic tumors where the effect of genomic changes on tumorigenesis is relatively smaller than in familial cancer. Our results and analysis strategy will be helpful to elucidate pathogenesis of CRCs or to develop biomarkers for predicting prognosis.     

Fibrinogen β-derived Bβ(15-42) peptide protects against kidney ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury in the kidney is a major cause of acute kidney injury (AKI) in humans and is associated with significantly high mortality. To identify genes that modulate kidney injury and repair, we conducted genome-wide expression analysis in the rat kidneys after I/R and found that the mRNA levels of fibrinogen (Fg)α, Fgβ, and Fgγ chains significantly increase in the kidney and remain elevated throughout the regeneration process. Cellular characterization of Fgα and Fgγ chain immunoreactive proteins shows a predominant expression in renal tubular cells and the localization of immunoreactive Fgβ chain protein is primarily in the renal interstitium in healthy and regenerating kidney. We also show that urinary excretion of Fg is massively increased after kidney damage and is capable of distinguishing human patients with acute or chronic kidney injury (n = 25) from healthy volunteers (n = 25) with high sensitivity and specificity (area under the receiver operating characteristic of 0.98). Furthermore, we demonstrate that Fgβ-derived Bβ(15-42) peptide administration protects mice from I/R-induced kidney injury by aiding in epithelial cell proliferation and tissue repair. Given that kidney regeneration is a major determinant of outcome for patients with kidney damage, these results provide new opportunities for the use of Fg in diagnosis, prevention, and therapeutic interventions in kidney disease.     

Physiologic Characteristics and Clinical Outcomes of Patients With Discordance Between FFR and iFR

ObjectivesThis study evaluated the physiologic characteristics of discordant lesions between instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) and the prognosis at 5 years.BackgroundFFR or iFR have been standard methods for assessing the functional significance of coronary artery stenosis. However, limited data exist about the physiologic characteristics of discordant lesions and the prognostic implications resulting from these lesions.MethodsA total of 840 vessels from 596 patients were classified according to iFR and FFR; high iFR–high FFR (n = 580), low iFR–high FFR (n = 40), high iFR–low FFR (n = 69), and low iFR–low FFR (n = 128) groups, which were compared with a control group (n = 23). The differences in coronary circulatory indices including the coronary flow reserve (CFR), index of microcirculatory resistance (IMR), and resistance reserve ratio (RRR) (resting distal arterial pressure × mean transit time / hyperemic distal arterial pressure × hyperemic mean transit time), which reflect the vasodilatory capacity of coronary microcirculation, were compared. Patient-oriented composite outcomes (POCO) at 5 years including all-cause death, any myocardial infarction, and any revascularization were compared among patients with deferred lesions.ResultsIn the low iFR–high FFR group, CFR, RRR, and IMR measurements were similar to the low iFR–low FFR group: CFR 2.71 versus 2.43 (p = 0.144), RRR 3.36 versus 3.68 (p = 0.241), and IMR 18.51 versus 17.38 (p = 0.476). In the high iFR–low FFR group, the CFR, RRR, and IMR measurements were similar to the control group: CFR 2.95 versus 3.29 (p = 0.160), RRR 4.28 versus 4.00 (p = 0.414), and IMR 17.44 versus 17.06 (p = 0.818). Among the 4 groups, classified by iFR and FFR, CFR and RRR were all significantly different, except for IMR. However, there were no significant differences in the rates of POCO, regardless of discordance between the iFR and FFR. Only the low iFR–low FFR group had a higher POCO rate compared with the high iFR–high FFR group (adjusted hazard ratio: 2.46; 95% confidence interval: 1.17 to 5.16; p = 0.018).ConclusionsDifferences in coronary circulatory function were found, especially in the vasodilatory capacity between the low iFR–high FFR and high iFR–low FFR groups. FFR–iFR discordance was not related to an increased risk of POCO among patients with deferred lesions at 5 years. (Clinical, Physiological and Prognostic Implication of Microvascular Status; NCT02186093; Physiologic Assessment of Microvascular Function in Heart Transplant Patients; NCT02798731)     

Dual Antiplatelet Therapy Duration Determines Outcome After 2- But Not 1-Stent Strategy in Left Main Bifurcation Percutaneous Coronary Intervention

Objectives

The aim of this study was to investigate clinical outcomes after left main coronary artery (LM) bifurcation percutaneous coronary intervention (PCI) and the impact of the duration of dual antiplatelet therapy (DAPT) according to treatment strategy.