A case of mediastinal goiter treated surgically using a clavicle-lifting technique

AbstractIntroductionMediastinal goiter is a benign disease, which is defined as a goiter with the greater portion of its mass lying below the thoracic inlet. It is controversial whether the cervical approach is the best approach for all mediastinal goiter surgeries.Case presentationA 71-year-old woman presented with respiratory discomfort during exertion. Computed tomography (CT) revealed a mediastinal goiter extending to the arch of the aorta. Surgical resection was performed using a clavicle-lifting technique. The excised specimen was 13×10×5cm in size and weighed 220g. The pathological diagnosis was nodular goiter.DiscussionThe clavicle-lifting technique is a simple and safe technique that involves lifting the clavicles with a pediatric extension retractor (Kent Retractor Set, Takasago Medical Industry, Tokyo, Japan). This is a good choice for surgery on upper mediastinal lesions such as mediastinal goiters as it obviates the need for a median sternotomy.ConclusionAlthough further study is necessary, it appears that a transcervical approach using the clavicle-lifting technique may be an acceptable treatment for mediastinal goiters that extend to the aortic arch

A spectrum of clinical manifestations caused by host immune responses against Epstein-Barr virus infections.

Epstein-Barr virus (EBV), or human herpesvirus 4 (HHV-4), infects the vast majority of adults worldwide, and establishes both nonproductive (latent) and productive (lytic) infections. Host immune responses directed against both the lytic and latent cycle-associated EBV antigens induce a diversity of clinical symptoms in patients with chronic active EBV infections who usually contain an oligoclonal pool of EBV-infected lymphocyte subsets in their blood. Episomal EBV genes in the latent infection utilize an array of evasion strategies from host immune responses: the minimized expression of EBV antigens targeted by host cytotoxic T lymphocytes (CTLs), the down-regulation of cell adhesion molecule expression, and the release of virokines to inhibit the host CTLs. The oncogenic role of latent EBV infection is not yet fully understood, but latent membrane proteins (LMPs) expressed during the latency cycle have essential biological properties leading to cellular gene expression and immortalization, and EBV-encoded gene products such as viral interleukin-10 (vIL-10) and bcl-2 homologue function to survive the EBV-infected cells. The subsequent oncogenic DNA damage may lead to the development of neoplasms. EBV-associated NK/T cell lymphoproliferative disorders are prevalent in Asia, but quite rare in Western countries. The genetic immunological background, therefore, is closely linked to the development of EBV-associated neoplasms.</p

Precipitant-Free Lysozyme Crystals Grown by Centrifugal Concentration Reveal Structural Changes

The three-dimensional (3D) structure of a protein molecule in its crystal need not correspond to that found in vivo in many cases, since we usually crystallize protein molecules using precipitants (salts, organic solvents, polymeric electrolytes, etc.), and the precipitants are often incorporated into crystals along with the protein molecules. Although precipitant-free crystallization methods would solve these problems, such methods had not yet been established. We have achieved a novel precipitant-free crystallization method by liquid-liquid phase separation during the centrifugal concentration of lysozyme in ultra-pure water. In the 3D structure of the precipitant-free crystal, lysozyme loses a sodium cation and changes the position of Ser 72. Deionization of the solution also appears to induce a change in the position of Asp 101 and an increase in the activity of lysozyme

Structural Basis of the Autophagy-Related LC3/Atg13 LIR Complex: Recognition and Interaction Mechanism

SummaryAutophagy is a bulk degradation pathway that removes cytosolic materials to maintain cellular homeostasis. The autophagy-related gene 13 (Atg13) and microtubule associate protein 1 light chain 3 (LC3) proteins are required for autophagosome formation. We demonstrate that each of the human LC3 isoforms (LC3A, LC3B, and LC3C) interacts with Atg13 via the LC3 interacting region (LIR) of Atg13. Using X-ray crystallography, we solved the macromolecular structures of LC3A and LC3C, along with the complex structures of the LC3 isoforms with the Atg13 LIR. Together, our structural and binding analyses reveal that the side-chain of Lys49 of LC3 acts as a gatekeeper to regulate binding of the LIR. We verified this observation by mutation of Lys49 in LC3A, which significantly reduces LC3A positive puncta formation in cultured cells. Our results suggest that specific affinity of the LC3 isoforms to the Atg13 LIR is required for proper autophagosome formation