Preoperative radiographic and histopathologic evaluation of central chondrosarcoma

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. 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). 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. 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.ArticleARCHIVES OF ORTHOPAEDIC AND TRAUMA SURGERY. 133(9):1225-1231 (2013)journal articl

Metastatic Carcinoma to Subcutaneous Tissue and Skeletal Muscle: Clinicopathological Features in 11 Cases

Objective: Metastatic carcinoma to subcutaneous tissue or skeletal muscle is relatively rare. The present study aimed to clarify the clinicopathological features for confirming the diagnosis as soft tissue metastasis and determining the primary site. Methods: We reviewed records of 11 patients with soft tissue metastasis who were in our institution from 1996 to 2009. Results: In 9 of 10 patients who underwent magnetic resonance imaging, findings consisted of poorly circumscribed high-intensity lesions around the tumor on T2-weighted images, irregular peritumoral enhancement and poorly enhanced lesions at the center of the tumor on T1-weighted images. Systematic immunohistochemical examination was more valuable for diagnosing as soft tissue metastasis and confirming the primary site. The expression patterns of cytokeratins 7 and 20 and tissue-specific antibodies such as thyroid transcription factor-1, MUC5AC and CDX2 were useful diagnostic markers. The primary site could be determined in five patients with cytokeratin 7/20 immunophenotype and positivity for tissue-specific antibodies. In four cases, determination of the primary site finally became possible by comparison with the histological findings of operative specimens in past carcinoma and/or in consideration of radiological findings and the results of cytokeratin 7/20 phenotyping. Conclusions: Systematic immunohistochemical examination is helpful for confirmation of the primary origin in soft tissue metastasis of carcinoma in addition to clinical information such as the history and condition of past carcinoma, radiological findings and comparison between the histology of biopsy specimens and past carcinoma.ArticleJAPANESE JOURNAL OF CLINICAL ONCOLOGY. 41(3):358-364 (2011)journal articl

Mutations identified in engineered Escherichia coli with a reduced genome

Characterizing genes that regulate cell growth and survival in model organisms is important for understanding higher organisms. Construction of strains harboring large deletions in the genome can provide insights into the genetic basis of cell growth compared with only studying wild-type strains. We have constructed a series of genome-reduced strains with deletions spanning approximately 38.9% of the E. coli chromosome. Strains were constructed by combining large deletions in chromosomal regions encoding nonessential gene groups. We also isolated strains Δ33b and Δ37c, whose growth was partially restored by adaptive laboratory evolution (ALE). Genome sequencing of nine strains, including those selected following ALE, identified the presence of several Single Nucleotide Variants (SNVs), insertions, deletions, and inversions. In addition to multiple SNVs, two insertions were identified in ALE strain Δ33b. The first was an insertion at the promoter region of pntA, which increased cognate gene expression. The second was an insertion sequence (IS) present in sibE, encoding the antitoxin in a toxin-antitoxin system, which decreased expression of sibE. 5 strains of Δ37c independently isolated following ALE harboring multiple SNVs and genetic rearrangements. Interestingly, a SNV was identified in the promoter region of hcaT in all five strains, which increased hcaT expression and, we predict, rescued the attenuated Δ37b growth. Experiments using defined deletion mutants suggested that hcaT encodes a 3-phenylpropionate transporter protein and is involved in survival during stationary phase under oxidative stress. This study is the first to document accumulation of mutations during construction of genome-reduced strains. Furthermore, isolation and analysis of strains derived from ALE in which the growth defect mediated by large chromosomal deletions was rescued identified novel genes involved in cell survival

Multifocal Periosteal Chondromas in the Ring Finger of an Adolescent Boy: Case Report

We describe an unusual case of a 12-year-old boy who presented with a loss of motion in the ring finger caused by 2 separate periosteal chondromas involving the proximal and middle phalanges. Range of motion improved and recurrence did not occur at the 5-year follow-up after marginal excision of both lesions. (J Hand Surg 2011;36A:101-105.ArticleJOURNAL OF HAND SURGERY-AMERICAN VOLUME. 36A(1):101-105 (2011)journal articl

Theory of optical transitions in graphene nanoribbons

Matrix elements of electron-light interactions for armchair and zigzag graphene nanoribbons are constructed analytically using a tight-binding model. The changes in wavenumber ($\Delta n$) and pseudospin are the necessary elements if we are to understand the optical selection rule. It is shown that an incident light with a specific polarization and energy, induces an indirect transition ($\Delta n=\pm1$), which results in a characteristic peak in absorption spectra. Such a peak provides evidence that the electron standing wave is formed by multiple reflections at both edges of a ribbon. It is also suggested that the absorption of low-energy light is sensitive to the position of the Fermi energy, direction of light polarization, and irregularities in the edge. The effect of depolarization on the absorption peak is briefly discussed.Comment: 11 pages, 7 figure

Side-scattered finger-photoplethysmography: experimental investigations toward practical noninvasive measurement of blood glucose

The aim of this study was to discover a simple/convenient geometrical arrangement of radiation sources and detector to acquire finger-photoplethysmograms (PPGs) with wavelength regions of blood glucose (BGL) absorption, toward practical noninvasive BGL measurement. First, we compared PPGs with three wavelengths: 808 nm (without water absorption), 1160 nm (with weak water absorption), and 1600 nm (with nearly peak BGL absorption and strong water absorption), while the source-detector spacing was successively increased circumferentially around a fingertip. In 10 healthy subjects, we observed clear cardiac-related pulsatile components of PPG signals at 808 and 1160 nm in any incident positions with more than 15 dB of signal-to-noise ratio (S/N), but reliable PPG detections at 1600 nm with more than 10 dB of S/N was only possible when the source-detector distance was less than 3mm around the fingertip circumference. Second, with this arrangement, an experiment was performed using six wavelengths to cover glucose absorption bands (from 1550 to 1749 nm), obtaining pulsatile PPG signals with more or less 15 dB of S/N. Through the present experiments, this orthogonal arrangement of the source and detector to detect forward-and side-scattered radiation through the tissue is appropriate for PPG measurements with wavelength regions where there is potential for BGL measurement

Synthetic and biochemical studies on the effect of persulfidation on disulfide dimer models of amyloid β42 at position 35 in Alzheimer's etiology

Protein persulfidation plays a role in redox signaling as an anti-oxidant. Dimers of amyloid β42 (Aβ42), which induces oxidative stress-associated neurotoxicity as a causative agent of Alzheimer's disease (AD), are minimum units of oligomers in AD pathology. Met35 can be susceptible to persulfidation through its substitution to homoCys residue under the condition of oxidative stress. In order to verify whether persulfidation has an effect in AD, herein we report a chemical approach by synthesizing disulfide dimers of Aβ42 and their evaluation of biochemical properties. A homoCys-disulfide dimer model at position 35 of Aβ42 formed a partial β-sheet structure, but its neurotoxicity was much weaker than that of the corresponding monomer. In contrast, the congener with an alkyl linker generated β-sheet-rich 8–16-mer oligomers with potent neurotoxicity. The length of protofibrils generated from the homoCys-disulfide dimer model was shorter than that of its congener with an alkyl linker. Therefore, the current data do not support the involvement of Aβ42 persulfidation in Alzheimer's disease