Atlantoaxial Instability after Treatment of Atlantoaxial Rotatory Fixation: A Case Report.

Introduction: We encountered a case of atlantoaxial subluxation (AAS) after treatment of atlantoaxial rotatory fixation (AARF). Reports of developing AAS after AARF are extremely rare. Case Report: An 8-year-old male who feels neck pain was diagnosed with AARF type II according to the Fielding classification. Computed tomography (CT) showed that the atlas was rotated 32° to the right relative to the axis. Neck collar, Glisson traction, and reduction under anesthesia were performed. Five months after the onset of AARF, the patient was diagnosed with AAS due to dilatation of atlantodental interval (ADI) and underwent posterior cervical fusion. Conclusion: AARF treatments, such as long-term Glisson traction and reduction under general anesthesia, which exert a stress on the cervical spine, may damage the alar ligaments, apical ligaments, lower longitudinal band, and Gruber's ligament. Transverse ligament damage can also occur during the treatment of AARF, especially if AARF is refractory or requires long-term treatment. In addition, knowledge of the pathophysiology of atlantoaxial instability after AARF treatment is important.

Conditional ablation of heparan sulfate expression in stromal fibroblasts promotes tumor growth in vivo.

Heparan sulfate (HS) is a glycocalyx component present in the extracellular matrix and cell-surface HS proteoglycans (HSPGs). Although HSPGs are known to play functional roles in multiple aspects of tumor development and progression, the effect of HS expression in the tumor stroma on tumor growth in vivo remains unclear. We conditionally deleted Ext1, which encodes a glycosyltransferase essential for the biosynthesis of HS chains, using S100a4-Cre (S100a4-Cre; Ext1f/f) to investigate the role of HS in cancer-associated fibroblasts, which is the main component of the tumor microenvironment. Subcutaneous transplantation experiments with murine MC38 colon cancer and Pan02 pancreatic cancer cells demonstrated substantially larger subcutaneous tumors in S100a4-Cre; Ext1f/f mice. Additionally, the number of myofibroblasts observed in MC38 and Pan02 subcutaneous tumors of S100a4-Cre; Ext1f/f mice decreased. Furthermore, the number of intratumoral macrophages decreased in MC38 subcutaneous tumors in S100a4-Cre; Ext1f/f mice. Finally, the expression of matrix metalloproteinase-7 (MMP-7) markedly increased in Pan02 subcutaneous tumors in S100a4-Cre; Ext1f/f mice, suggesting that it may contribute to rapid growth. Therefore, our study demonstrates that the tumor microenvironment with HS-reduced fibroblasts provides a favorable environment for tumor growth by affecting the function and properties of cancer-associated fibroblasts, macrophages, and cancer cells.

The malignant transformation of osteoid osteoma in the cervical spine to high-grade osteosarcoma: a case report and review of literature.

PURPOSE: Osteoid osteoma occasionally occur in the spine, but their malignant transformation is not common. We present an extremely rare case of the malignant transformation of an osteoid osteoma to high-grade osteosarcoma that formed in the pedicle and spread to the lateral mass of the cervical spine. CASE PRESENTATION: We report the case of an 18-year-old man who suffered from neck pain as an initial symptom. The size of the radiolucent lesion was 12 mm in diameter at the time of diagnosis. Intralesional tumour resection and autologous bone grafting were performed. The remaining tumour grew gradually for 40 months after the surgery; therefore, the tumour had grown rapidly till 51 months after the initial diagnosis. At this stage, the tumour size was approximately 6-fold larger than the initial size, and resulted in progressive paraplegia. A biopsy revealed that the tumour had transformed into a high-grade osteosarcoma. Heavy charged particle irradiation was performed to control tumour growth. CONCLUSIONS: There is a possibility of malignant transformation of osteoid osteoma. Patients with osteoid osteoma or osteoblastoma should be carefully observed, especially for recurrent tumours after an intralesional resection.

Simple and efficient chiral dopants to induce blue phases and their optical purity effects on the physical properties of blue phases.

Blue phases (BPs) have received considerable attention as light shutters in the next generation of liquid crystal (LC) displays. However, no simple and efficient chiral dopant for induction of BPs of commercially available rodlike LC compounds has been reported. In this study, both (R) and (S) forms of novel chiral dopants were synthesized, showed extremely high helical twisting power values in nematic LC compounds, and induced stable BPs with a small amount of our chiral dopants (3-5 mol %). In enantiomeric excess controlled experiments, we found novel phenomena in their physical properties, such as generation of a metastable chiral nematic phase between an isotropic state and a BP.

Quick shear-flow alignment of biological filaments for X-ray fiber diffraction facilitated by methylcellulose.

X-ray fiber diffraction is one of the most useful methods for examining the structural details of live biological filaments under physiological conditions. To investigate biologically active or labile materials, it is crucial to finish fiber alignment within seconds before diffraction analysis. However, the conventional methods, e.g., magnetic field alignment and low-speed centrifugations, are time-consuming and not very useful for such purposes. Here, we introduce a new alignment method using a rheometer with two parallel disks, which was applied to observe fiber diffractions of axonemes, tobacco mosaic tobamovirus, and microtubules. We found that fibers were aligned within 5 s by giving high shear flow (1000-5000 s(-1)) to the medium and that methylcellulose contained in the medium (approximately 1%) was essential to the accomplishment of uniform orientation with a small angular deviation (<5 degrees). The new alignment method enabled us to execute structure analyses of axonemes by small-angle x-ray diffraction. Since this method was also useful for the quick alignment of purified microtubules, as well as tobacco mosaic tobamovirus, we expect that we can apply it to the structural analysis of many other biological filaments.

Pathological and phylogenetic features of prevalent canine distemper viruses in wild masked palm civets in Japan.

Ten wild masked palm civets infected with canine distemper virus (CDV), captured in Japan from 2005 to 2007, were histopathologically and phylogenetically analyzed. Phylogenetic analysis based on the amino acid sequences of the H protein of two CDV isolates from masked palm civets revealed that the two isolates were classified into the clade of recent isolates in Japan. Histopathologically marked lesions of virus encephalitis were present in the brain, whereas gastrointestinal lesions were absent or at a mild degree. The distribution of the lesions resembles that of recent CDV cases in dogs. Therefore, recent CDV infections in masked palm civets could be caused by recently prevalent CDV in dogs. The possibility of the masked palm civet as a spreader of CDV among wildlife is also discussed.