Preoperative radiographic and histopathologic evaluation of central chondrosarcoma

Background

Distinguishing grade 1 chondrosarcoma from grade 2 chondrosarcoma is critical both for planning the surgical procedure and for predicting the outcome. We aimed to review the preoperative radiographic and histologic findings, and to evaluate the reliability of preoperative grading.

Methods

We retrospectively reviewed the medical records of 17 patients diagnosed with central chondrosarcoma at our institution between 1996 and 2011. In these cases, we compared the preoperative and postoperative histologic grades, and evaluated the reliability of the preoperative histologic grading. We also assessed the preoperative radiographic findings obtained using plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI).

Results

Preoperative histologic grade was 1 in 12 patients, 2 in 4 patients, and 3 in 1 patient. However, 6 of the 12 cases classified as grade 1 before surgery were re-classified as grade 2 postoperatively. In the radiographic evaluation, grade 1 was suspected by the presence of a ring-and-arc pattern of calcification on plain radiography and CT and entrapped fat and ring-and-arc enhancement on MRI. Grades 2 and 3 were suspected by the absence of calcification and the presence of cortical penetration and endosteal scalloping on plain radiography and CT, as well as soft-tissue mass formation on MRI.

Conclusion

Although the combination of radiographic interpretation and histologic findings may improve the accuracy of preoperative grading in chondrosarcoma, the establishment of a standard evaluation system with the histologic and radiographic findings and/or the development of new biologic markers are necessary for preoperative discrimination of low-grade chondrosarcoma from high-grade chondrosarcoma.     

Management of traumatic aortic rupture

A traumatic thoracic aortic injury is a severe and life-threatening clinical entity. Although largely fatal; if untreated, these injuries are amenable to surgical repair if appropriately diagnosed. Therefore, early triage of this condition is critically important. Unfortunately, aortic injuries rarely occur in isolation, and there has been no good cutoff value to help select the appropriate surgical strategy. Algorithms for the both diagnosis and treatment of traumatic thoracic aortic injury have undergone changes in recent years. There have been several case reports, retrospective series and registry data describing the treatment of patients with traumatic thoracic aortic rupture using endovascular treatment. Endovascular treatment is a less-invasive management option for polytraumatized patients. Because it is less invasive, without the need for thoracotomy or the use of heparin, endovascular repair can be performed even in acutely injured patients, without the risk of destabilizing pulmonary, head or abdominal traumatic lesions. Long-term follow-up especially in young patients is necessary after endovascular treatment.     

Zinc-finger nuclease-mediated targeted insertion of reporter genes for quantitative imaging of gene expression in sea urchin embryos

To understand complex biological systems, such as the development of multicellular organisms, it is important to characterize the gene expression dynamics. However, there is currently no universal technique for targeted insertion of reporter genes and quantitative imaging in multicellular model systems. Recently, genome editing using zinc-finger nucleases (ZFNs) has been reported in several models. ZFNs consist of a zinc-finger DNA-binding array with the nuclease domain of the restriction enzyme FokI and facilitate targeted transgene insertion. In this study, we successfully inserted a GFP reporter cassette into the HpEts1 gene locus of the sea urchin, Hemicentrotus pulcherrimus. We achieved this insertion by injecting eggs with a pair of ZFNs for HpEts1 with a targeting donor construct that contained ～1-kb homology arms and a 2A-histone H2B-GFP cassette. We increased the efficiency of the ZFN-mediated targeted transgene insertion by in situ linearization of the targeting donor construct and cointroduction of an mRNA for a dominant-negative form of HpLig4, which encodes the H. pulcherrimus homolog of DNA ligase IV required for error-prone nonhomologous end joining. We measured the fluorescence intensity of GFP at the single-cell level in living embryos during development and found that there was variation in HpEts1 expression among the primary mesenchyme cells. These findings demonstrate the feasibility of ZFN-mediated targeted transgene insertion to enable quantification of the expression levels of endogenous genes during development in living sea urchin embryos.     

Topological specificity and hierarchical network of the circadian calcium rhythm in the suprachiasmatic nucleus

The circadian pacemaker in the hypothalamic suprachiasmatic nucleus (SCN) is a hierarchical multioscillator system in which neuronal networks play crucial roles in expressing coherent rhythms in physiology and behavior. However, our understanding of the neuronal network is still incomplete. Intracellular calcium mediates the input signals, such as phase-resetting stimuli, to the core molecular loop involving clock genes for circadian rhythm generation and the output signals from the loop to various cellular functions, including changes in neurotransmitter release. Using a unique large-scale calcium imaging method with genetically encoded calcium sensors, we visualized intracellular calcium from the entire surface of SCN slice in culture including the regions where autonomous clock gene expression was undetectable. We found circadian calcium rhythms at a single-cell level in the SCN, which were topologically specific with a larger amplitude and more delayed phase in the ventral region than the dorsal. The robustness of the rhythm was reduced but persisted even after blocking the neuronal firing with tetrodotoxin (TTX). Notably, TTX dissociated the circadian calcium rhythms between the dorsal and ventral SCN. In contrast, a blocker of gap junctions, carbenoxolone, had only a minor effect on the calcium rhythms at both the single-cell and network levels. These results reveal the topological specificity of the circadian calcium rhythm in the SCN and the presence of coupled regional pacemakers in the dorsal and ventral regions. Neuronal firings are not necessary for the persistence of the calcium rhythms but indispensable for the hierarchical organization of rhythmicity in the SCN.     

Volumetric changes of transferred free anterolateral thigh flaps in head and neck lesions

ObjectiveThe purpose of this study was to clarify sequential volumetric changes of anterolateral thigh (ALT) flaps transferred to head and neck lesions.Patients and methodsWe retrospectively analyzed volumetric changes in fat and muscle of 22 ALT flaps. We assessed “true” flap volume using the water-displacement method intraoperatively. Postoperative flap volume was assessed using three-dimensional volume-calculating software.ResultsThe average duration until the entire flap volume decreased to its minimal size was 8.7 months. After 8.7 months, entire flap volume decreased to 47.4% of its initial intraoperative volume. The fat volume decreased to 62.5%, and the muscle volume decreased to 30.2%. The rate of muscle volume decrease was significantly larger than that of fat volume decrease (p<0.005). The only significant factor which affected entire flap volume decrease was the recipient site where the ALT flap was transferred (oral and pharyngeal lesions) (p=0.001), and the factor that affected fat volume decrease was postoperative body-weight loss (p=0.046).ConclusionTo minimize the influence of postoperative ALT flap volume decrease, an ALT flap should mainly comprise fatty tissue, and its size should be 1.6-times larger (100/62.5) than the ideal volume intraoperatively. Maintaining the body weight is crucial to avoid ALT flap volume decrease.     

Does Completion Thyroidectomy Improve the Outcome of Patients with Minimally Invasive Follicular Carcinoma of the Thyroid?

Background

The diagnosis of minimally invasive follicular thyroid carcinoma (MIFTC) is often made histologically after thyroid lobectomy. We attempted to determine whether completion thyroidectomy should be considered necessary for all patients diagnosed with MIFTC after thyroid lobectomy.

Methods

The subjects of this study were a total of 324 patients who underwent thyroid lobectomy as initial surgery at our institution between 1989 and 2010 and diagnosed histologically as MIFTC. Completion thyroidectomy was performed on 101 patients, and the other 223 patients were followed up without further treatments. Cumulative cause-specific survival (CSS) rates and distant-metastasis-free survival (DMFS) rates were calculated by the Kaplan–Meier method. Differences between groups were analyzed for statistical significance by the log-rank test. Multivariate analysis was performed by using the Cox proportional hazards model.

Results

During the follow-up period, 39 patients were diagnosed with distant metastasis, and 7 patients died of their disease. Age at the initial surgery was found to be a significant factor related to DMFS in both the univariate and multivariate analysis and to also be related to CSS in the univariate analysis. Completion thyroidectomy did not have a significant effect on DMFS or CSS according to the results of the univariate analysis, but it had significant effect on DMFS according to the results of the multivariate analysis.

Conclusions

Although we were unable to demonstrate sufficient statistical evidence that completion thyroidectomy improved the outcome of MIFTC patients, it is noteworthy none of the patient who underwent completion thyroidectomy died of the disease.