Discrepancy between subjective and objective sleepiness in adolescents.

Background: Lack of correlation between subjective and objective measurements of daytime sleepiness is common. Here, the frequency of discrepancy between subjective and objective sleepiness, as well as possible predictors, were examined for an adolescent cohort.

Methods: This study included pediatric patients (aged 10-18 years, n = 211) with various sleep disorder symptoms were evaluated between August 2011 and February 2021.

Biomechanical comparison of arthroscopic and open lunate excisions in the cadaveric wrist.

Background: In advanced Kienböck disease, unreconstructible lunate should be excised as a salvage procedure. There is a lack of information about the biomechanical approaches evaluating the carpal kinematics after lunate excision. We hypothesized that arthroscopic lunate excision would not break the ring structure of the proximal carpal row, preventing carpal instability.

Biomechanical analysis of simultaneous distal and proximal radio-ulnar joint instability.

Background: Simultaneous dislocation of the proximal and distal radio-ulnar joints without bony injuries has been reported, but the mechanism remains unclear. We investigated concurrent proximal and distal radio-ulnar joint instability after sequential sectioning of the annular ligament, triangular fibrocartilage complex, and quadrate ligament.

Methods: We performed this biomechanical study with six fresh-frozen cadaveric upper extremities.

Robust method to create a standardized and reproducible atrophic non-union model in a rat femur.

Objective: No evidence exists about which biological approach is more reliable for creating non-union model. We investigated how to create a reproducible atrophic non-union model in a rat femur.

Methods: We compared three groups: simple osteotomy (group A), partial periosteum cauterization (group B), and extensive periosteum and bone marrow resection (group C).

Safe zone of pin insertion for nonbridging external fixators in distal radial fractures: MRI analysis.

Background: Of the anatomical reduction and fixation methods used to treat distal radius fracture, non-bridging external fixation has the advantage of enabling early wrist motion. The surgical technique relies on successful placement of the pin in individual fracture fragments. The present study aimed to identify the safe zone of pin insertion for a non-bridging external fixator into the distal radius that avoids metal impingement of extensor tendons.

Effect of soft tissue injury and ulnar angulation on radial head instability in a Bado type I Monteggia fracture model.

The effects of soft tissue damage and ulnar angulation deformity on radial head instability in Monteggia fractures are unclear. We tested the hypothesis that radial head instability correlates with the magnitude of ulnar angular deformity and the degree of proximal forearm soft tissue injury in Bado type I Monteggia fractures.We performed a biomechanical study in 6 fresh-frozen cadaveric upper extremities.

Effects of 7 T static magnetic fields on the expression of biological markers and the formation of bone in rats.

In this study, we aimed to evaluate the effects of 7 T static magnetic fields (SMFs) on rat mesenchymal stem cells (MSCs) in order to determine whether strong SMFs affected the osteogenesis of MSCs. MSCs were prepared from bone marrow cells obtained from the femurs of 7-week-old male Fischer 344 rats. MSCs were then combined with β-tricalcium phosphate (β-TCP), yielding two types of TCP/MSC constructs (TCP/P-1 and P-2) on day 0.

Osteogenic extracellular matrix sheet for bone tissue regeneration.

The application of extracellular matrix (ECM) sheets without a scaffold is not extensively reported in bone regenerative medicine. The aim of the present study was to demonstrate that an osteogenic ECM sheet (OECMS) can retain ECM integrity and growth factors to enhance bone formation in a rat non-union model. OECMS was produced from osteogenic cell sheets (OCS).

Osteogenesis of osteogenic matrix cell sheets preserved in culture medium in a rat model.

Osteogenic matrix cell sheets (OMCSs) are ideal for bone regeneration. Transportation of OMCSs may be necessary, during which their osteogenic ability must be maintained. Here, we evaluated different media and temperatures for OMCS preservation.

Supplying osteogenesis to dead bone using an osteogenic matrix cell sheet.

Purpose: To evaluate whether osteogenic matrix cell sheets can supply osteogenesis to dead bone.

Methods: Femur bone fragments (5 mm in length) were obtained from Fisher 344 rats and irradiated by a single exposure of 60 Gy to produce bones that were no longer viable. Osteogenic matrix cell sheets were created from rat bone marrow-derived stromal cells (BMSCs).

A gold nano-electrode for single ion channel recordings.

The artificial bilayer single channel recording technique is commonly used to observe the detailed physiological properties of various ion channel proteins. It permits easy control of the solution and membrane lipid composition, and is also compatible with pharmacological screening devices. However, its use is limited due to low measurement efficiency.

Bone regeneration with osteogenic matrix cell sheet and tricalcium phosphate: An experimental study in sheep.

Aim: To determine the effects of a cell sheet created from sheep bone marrow and tricalcium phosphate (TCP) on osteogenesis.

Methods: Bone marrow cells were harvested from a sheep and cultured in a minimal essential medium (MEM) containing ascorbic acid phosphate (AscP) and dexamethasone (Dex). After 2 wk, the formed osteogenic matrix cell sheet was lifted from the culture dish using a scraper.

Implantation of Bone Marrow Stromal Cell Sheets Derived from Old Donors Supports Bone Tissue Formation.

The purpose of this study was to evaluate the osteogenesis ability of osteogenic matrix cell sheets (OMCS) derived from old donor cells. Bone marrow stromal cells (BMSC) were obtained from young (7-week-old) and old (1-year-old) Fischer344 rats donors and cultured with modified Eagle's medium (MEM group) alone or containing dexamethasone (Dex; 10 nM) and ascorbic acid phosphate (AscP; 0.28 mM) (Dex/AscP group).

Modifying oxygen tension affects bone marrow stromal cell osteogenesis for regenerative medicine.

Aim: To establish a hypoxic environment for promoting osteogenesis in rat marrow stromal cells (MSCs) using osteogenic matrix cell sheets (OMCSs).

Methods: Rat MSCs were cultured in osteogenic media under one of four varying oxygen conditions: Normoxia (21% O) for 14 d (NN), normoxia for 7 d followed by hypoxia (5% O) for 7 d (NH), hypoxia for 7 d followed by normoxia for 7 d (HN), or hypoxia for 14 d (HH). Osteogenesis was evaluated by observing changes in cell morphology and calcium deposition, and by measuring osteocalcin secretion (ELISA) and calcium content.

Importance of anterior humeral line for successful anatomical reduction in the surgical treatment of pediatric supracondylar humeral fractures.

Anterior humeral line (AHL) and tilting angle (TA) are used for the assessment of pediatric elbow sagittal plane alignment in surgical treatment of pediatric supracondylar humeral fracture. However, few studies exist that compare the reliabilities between these parameters. The purpose of this study is to determine whether measurements of radiographic parameters are reliable and useful for achieving anatomical reduction.

A Biomechanical Perspective on Distal Radioulnar Joint Instability.

 The purpose of this article was to review the anatomy, kinematics of the distal radioulnar joint (DRUJ), and to discuss definition, classification, and diagnosis of DRUJ instability.  A biomechanical perspective on physical examination of DRUJ ballottement test was documented. Physiological dynamic DRUJ translation and differences of the translation following sequential ligament sectioning and changes in different forearm and wrist positions were demonstrated.

Septic arthritis of the wrist caused by e: a case report.

Septic arthritis of the wrist is rare entity, especially; atypical mycobacterial infection of the wrist is extremely rare. We report a case of septic arthritis of the wrist caused by , which was successfully treated by radical debridement followed by wrist arthrodesis using vascularised fibular grafting.

Calcium Concentration in Culture Medium as a Nondestructive and Rapid Marker of Osteogenesis.

Artificial bones made of β-tricalcium phosphate (β-TCP) combined with bone marrow-derived mesenchymal stromal cells (BM-MSCs) are used for effective reconstruction of bone defects caused by genetic defects, traumatic injury, or surgical resection of bone tumors. However, the selection of constructs with high osteogenic potential before implantation is challenging. The purpose of this study was to determine whether the calcium concentration in BM-MSC culture medium can be used as a nondestructive and simple osteogenic marker for selecting tissue-engineered grafts constructed using β-TCP and BM-MSCs.

Culturing bone marrow cells with dexamethasone and ascorbic acid improves osteogenic cell sheet structure.

Objectives: To assess the structure and extracellular matrix molecule expression of osteogenic cell sheets created via culture in medium with both dexamethasone (Dex) and ascorbic acid phosphate (AscP) compared either Dex or AscP alone.

Methods: Osteogenic cell sheets were prepared by culturing rat bone marrow stromal cells in a minimal essential medium (MEM), MEM with AscP, MEM with Dex, and MEM with Dex and AscP (Dex/AscP). The cell number and messenger (m)RNA expression were assessed in vitro, and the appearance of the cell sheets was observed after mechanical retrieval using a scraper.

The expression of miR-124 increases in aged skin to cause cell senescence and it decreases in squamous cell carcinoma.

Skin senescence is induced by various factors including intrinsic aging and extrinsic aging. The current study compared the expression of microRNAs in young facial skin and senescent facial skin, and this study identified skin aging-related microRNAs. According to the results from a microRNA PCR Array, miR-124 was the microRNA that increased the most in senescent skin compared to young skin.

Establishment and gene expression analysis of disease-derived induced pluripotent stem cells of scleroderma.

Background: We recently generated induced pluripotent stem cells (iPSCs) from cultured dermal fibroblasts of systemic sclerosis (SSc-iPSC) to study the disease mechanisms.

Objective: In the present study, we have performed gene expression analysis using cultured SSc dermal fibroblasts, SSc-iPSC, and fibroblasts re-differentiated from SSc-iPSC (SSc-iPSC-FB).

Methods: mRNA and protein levels of collagen and integrins were analyzed using PCR array, PCR, immunoblotting, and immunofluorescence.

Biomechanical study of distal radioulnar joint ballottement test.

We investigated the reliability and accuracy of the distal radioulnar joint (DRUJ) ballottement test using five fresh-frozen cadaver specimens in triangular fibrocartilage complex (TFCC)-intact, and TFCC-sectioned wrists. The humerus and proximal ulna were fixed. The ulna was allowed to translate in dorsopalmar directions without rotation, and the radius was allowed to move freely.

Vascularized Bone Grafts from the Dorsal Wrist for the Treatment of Kienböck Disease.

Purpose The objective of this article is to evaluate functional and radiological outcomes of vascularized bone grafts for stage 2 and 3 Kienböck disease. The outcomes of three different donor sites via dorsal approach of the wrist were compared. Pearls and pitfalls in surgical technique were discussed.