This study aimed to examine the cortical microvessel diameter response to hypercapnia in misery perfusion using two-photon laser scanning microscopy (TPLSM). We evaluated whether the vascular response to hypercapnia could represent the cerebrovascular reserve. Cerebral blood flow (CBF) during normocapnia and hypercapnia was measured by laser-Doppler flowmetry through cranial windows in awake C57/BL6 mice before and at 1, 7, 14, and 28 days after unilateral common carotid artery occlusion (UCCAO). Diameters of the cortical microvessels during normocapnia and hypercapnia were also measured by TPLSM. Cerebral blood flow and the vascular response to hypercapnia were decreased after UCCAO. Before UCCAO, vasodilation during hypercapnia was found primarily in arterioles (22.9%±3.5%). At 14 days after UCCAO, arterioles, capillaries, and venules were autoregulatorily dilated by 79.5%±19.7%, 57.2%±32.3%, and 32.0%±10.8%, respectively. At the same time, the diameter response to hypercapnia in arterioles was significantly decreased to 1.9%±1.5%. A significant negative correlation was observed between autoregulatory vasodilation and the diameter response to hypercapnia in arterioles. Our findings indicate that arterioles play main roles in both autoregulatory vasodilation and hypercapnic vasodilation, and that the vascular response to hypercapnia can be used to estimate the cerebrovascular reserve.
cerebral blood flow; cerebrovascular reserve; misery perfusion; two-photon laser scanning microscopy; vascular response
Cortical neural activities lead to changes in the cerebral blood flow (CBF), which involves astrocytic control of cerebrovascular tone. However, the manner in which astrocytic activity specifically leads to vasodilation or vasoconstriction is difficult to determine. Here, cortical astrocytes genetically expressing a light-sensitive cation channel, channelrhodopsin-2 (ChR2), were transcranially activated with a blue laser while the spatiotemporal changes in CBF were noninvasively monitored with laser speckle flowgraphy in the anesthetised mouse cortex. A brief photostimulation induced a fast transient increase in CBF. The average response onset time was 0.7 ± 0.7 sec at the activation foci, and this CBF increase spread widely from the irradiation spot with an apparent propagation speed of 0.8–1.1 mm/sec. The broad increase in the CBF could be due to a propagation of diffusible vasoactive signals derived from the stimulated astrocytes. Pharmacological manipulation showed that topical administration of a K+ channel inhibitor (BaCl2; 0.1–0.5 mM) significantly reduced the photostimulation-induced CBF responses, which indicates that the ChR2-evoked astrocytic activity involves K+ signalling to the vascular smooth muscle cells. These findings demonstrate a unique model for exploring the role of the astrocytes in gliovascular coupling using non-invasive, time-controlled, cell-type specific perturbations.
Transcription factors SOX9, SOX5 and SOX6 are indispensable for generation and differentiation of chondrocytes. However, molecular mechanisms to induce the SOX genes are poorly understood. To address this issue, we previously determined the human embryonic enhancer of SOX6 by 5′RACE analysis, and identified the 46-bp core enhancer region (CES6). We initially performed yeast one-hybrid assay for screening other chondrogenic factors using CES6 as bait, and identified a zinc finger protein ZNF449. ZNF449 and Zfp449, a counterpart in mouse, transactivated enhancers or promoters of SOX6, SOX9 and COL2A1. Zfp449 was expressed in mesenchyme-derived tissues including cartilage, calvaria, muscle and tendon, as well as in other tissues including brain, lung and kidney. In limb cartilage of mouse embryo, Zfp449 protein was abundantly located in periarticular chondrocytes, and decreased in accordance with the differentiation. Zfp449 protein was also detected in articular cartilage of an adult mouse. During chondrogenic differentiation of human mesenchymal stem cells, ZNF449 was increased at an early stage, and its overexpression enhanced SOX9 and SOX6 only at the initial stage of the differentiation. We further generated Zfp449 knockout mice to examine the in vivo roles; however, no obvious abnormality was observed in skeletal development or articular cartilage homeostasis. ZNF449 may regulate chondrogenic differentiation from mesenchymal progenitor cells, although the underlying mechanisms are still unknown.
Schwann cells are an important cell source for regenerative therapy for neural disorders. We investigated the role of the transcription factor sex determining region Y (SRY)-box 10 (SOX10) in the proliferation and myelination of Schwann cells. SOX10 is predominantly expressed in rat sciatic nerve-derived Schwann cells and is induced shortly after birth. Among transcription factors known to be important for the differentiation of Schwann cells, SOX10 potently transactivates the S100B promoter. In cultures of Schwann cells, overexpressing SOX10 dramatically induces S100B expression, while knocking down SOX10 with shRNA suppresses S100B expression. Here, we identify three core response elements of SOX10 in the S100B promoter and intron 1 with a putative SOX motif. Knockdown of either SOX10 or S100B enhances the proliferation of Schwann cells. In addition, using dissociated cultures of dorsal root ganglia, we demonstrate that suppressing S100B with shRNA impairs myelination of Schwann cells. These results suggest that the SOX10-S100B signaling axis critically regulates Schwann cell proliferation and myelination, and therefore is a putative therapeutic target for neuronal disorders.
To determine the utility of "PainVision" apparatus for the assessment of low back pain.
Overview of Literature
A newly developed device, the PainVision PS-2100 (Nipro, Osaka, Japan), has been used to assess the perception of pain in a quantitative manner. In the current study, we aimed to evaluate the efficacy of PainVision for the assessment of low back pain.
We assessed 89 patients with low back pain. The numeric rating scale (NRS) score, McGill Pain Questionnaire (MPQ) score and the degree of pain calculated by PainVision were measured twice at 4-week intervals in each patient. An electrode was patched on the forearm surface of the patients and the degree of pain was automatically calculated (degree of pain=100×[current producing pain comparable with low back pain-current at perception threshold/current at perception threshold]). Correlations between NRS and MPQ scores and the degree of pain were determined using Spearman's rank correlation test.
There was a strong correlation between the NRS and MPQ scores at each time point (rs=0.60, p<0.0001). The degree of pain also showed a moderate correlation with NRS and MPQ scores at each time point (rs=0.40, p<0.03). The change in the degree of pain over 4 weeks showed a moderate correlation with changes in the NRS and MPQ scores (rs=0.40, p<0.01).
PainVision as self-reported questionnaires is a useful tool to assess low back pain.
PainVision; Low back pain; Tool; Assessment
To clarify mechanisms through which activation of the nucleus basalis of Meynert (NBM) increases cerebral cortical blood flow, we examined whether cortical parenchymal arteries dilate during NBM stimulation in anesthetized mice. We used two-photon microscopy to measure the diameter of single penetrating arteries at different depths (∼800 μm, layers I to V) of the frontal cortex, and examined changes in the diameter during focal electrical stimulation of the NBM (0.5 ms at 30 to 50 μA and 50 Hz) and hypercapnia (3% CO2 inhalation). Stimulation of the NBM caused diameter of penetrating arteries to increase by 9% to 13% of the prestimulus diameter throughout the different layers of the cortex, except at the cortical surface and upper part of layer V, where the diameter of penetrating arteries increased only slightly during NBM stimulation. Hypercapnia caused obvious dilation of the penetrating arteries in all cortical layers, including the surface arteries. The diameters began to increase within 1 second after the onset of NBM stimulation in the upper cortical layers, and later in lower layers. Our results indicate that activation of the NBM dilates cortical penetrating arteries in a layer-specific manner in magnitude and latency, presumably related to the density of cholinergic nerve terminals from the NBM.
cerebral cortex; diameter; nucleus basalis of Meynert; penetrating artery; two-photon microscopy; vasodilation
The epithelial-mesenchymal-transition (EMT) is an important step in the invasion and metastasis of cancer. A critical molecular feature of this process is the downregulation of the E-cadherin expression, which is primarily controlled by Snail-related zinc-finger transcription factors. The aim of this study was to evaluate the prognostic impact of the expression of EMT-related proteins (E-cadherin and Snail) in patients with ovarian cancer.
An immunohistochemical analysis was conducted using tissue microarray samples of 174 primary tumors and 34 metastases of ovarian carcinoma, and the relationships between the protein expression, clinicopathological features and outcomes were investigated.
A reduced E-cadherin expression was observed in 36.8% of the primary tumors and 30.4%, 35.7%, 37.7% and 52.7% of the stage I, II, III and IV tumors, respectively. The nuclear expression of Snail was positive in 33.9% of the primary tumors. The rate of an EMT-positive status, as represented by both a reduced E-cadherin expression and a nuclear expression of Snail, was significantly higher in the patients with peritoneal dissemination than in those without (p < 0.05). The EMT status was significantly associated with both the progression-free survival and overall survival (p <0.01). A multivariate analysis showed an EMT-positive status to be a significant predictor of both the progression-free survival (p < 0.05) and overall survival (P < 0.01).
These data indicate that the EMT status is significantly associated with peritoneal metastasis and both the progression-free survival and overall survival in patients with ovarian cancer. Therefore, clarifying and controlling EMT signaling is a promising approach to molecular targeted therapy for ovarian cancer.
Epithelial-mesenchymal-transition; EMT; Snail; E-cadherin; Ovarian cancer
Effects of chronic hypoxia on hemodynamic response to sensory stimulation were investigated. Using laser-Doppler flowmetry, change in cerebral blood flow (CBF) was measured in awake mice, which were housed in a hypoxic chamber (8% O2) for 1 month. The degree of increase in CBF evoked by sensory stimulation was gradually decreased over 1 month of chronic hypoxia. No significant reduction of increase in CBF induced by hypercapnia was observed during 1 month. Voltage-sensitive dye (VSD) imaging of the somatosensory cortex showed no significant decrease in neural activation over 1 month, indicating that the reduction of increase in CBF to sensory stimulation was not caused by cerebrovascular or neural dysfunction. The simulation study showed that, when effective diffusivity for oxygen in the capillary bed (D) value increases by chronic hypoxia due to an increase in capillary blood volume, an increase in the cerebral metabolic rate of oxygen utilization during neural activation can occur without any increase in CBF. Although previous study showed no direct effects of acute hypoxia on CBF response, our finding showed that hemodynamic response to neural activation could be modified in response to a change in their balance to energy demand using chronic hypoxia experiments.
cerebral blood flow; energy metabolism; hemodynamics; microcirculation; neurovascular unit
Gemcitabine (2′, 2′ –difluorodeoxycytidine) is one of many nonplatinum drugs that exhibit activity in recurrent, platinum-resistant ovarian cancer. However, the molecular mechanisms by which Gemcitabine treatment inhibits the proliferation of platinum-resistant ovarian cancer cells still remain unclear. We investigated whether Gemcitabine increases the efficacy of Cisplatin in platinum-resistant ovarian cancer models in vitro and in vivo.
We used Cisplatin-resistant Caov-3 cells, A2780CP cells and Cisplatin-sensitive A2780 cells to examine the sensitivity of the cell viability of Cisplatin and Gemcitabine using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and the sensitivity of the invasive activity of Cisplatin and Gemcitabine using an invasion assay with Matrigel. We examined the Akt kinase activity and matrix metalloproteinase 9 (MMP9) expression following Cisplatin and Gemcitabine treatment using a Western blot analysis and the mRNA expression of vascular endothelial growth factor (VEGF) using semi-quantitative RT-PCR. Moreover, we evaluated the effects of Cisplatin and Gemcitabine on the intra-abdominal dissemination of ovarian cancer in vivo.
Gemcitabine significantly inhibited Cisplatin-induced Akt activation in the Caov-3 and A2780CP cells, but not in the A2780 cells. In the presence of Gemcitabine, Cisplatin-induced growth inhibition and apoptosis were significantly enhanced in the Caov-3 and A2780CP cells. Co-treatment with Cisplatin and Gemcitabine almost completely inhibited invasion of both types of cells through the Matrigel; however, neither Cisplatin nor Gemcitabine alone inhibited the invasion of both types of cells. Gemcitabine inhibited not only the Cisplatin-induced activation of Akt, but also the MMP9 and mRNA expression of VEGF. Moreover, treatment with Gemcitabine increased the efficacy of Cisplatin-induced growth inhibition of the intra-abdominal dissemination and production of ascites in the athymic nude mice inoculated with Caov-3 cells.
We herein demonstrated that Gemcitabine inhibits the Akt kinase activity and angiogenetic activity following treatment with Cisplatin in platinum-resistant ovarian cancer cells. These results provide a rationale for using Gemcitabine in clinical regimens containing molecular targeting agents against platinum-resistant ovarian cancers.
Gemcitabine; Ovarian cancer; Platinum resistance; PI3K/Akt cascade; Apoptosis; VEGF
Positron emission tomography (PET) study has shown that dopamine synthesis capacity varied among healthy individuals. This interindividual difference might be due to a difference in the cell-level structure of presynaptic dopaminergic neurons, i.e., cellular density and/or number. In this study, the relations between the dopamine synthesis capacity measured by PET and the parameter estimates in diffusion tensor imaging (DTI) in striatal subregions were investigated in healthy human subjects. DTI and PET studies with carbon-11 labeled L-DOPA were performed in ten healthy subjects. Age-related changes in the above parameters were also considered. Fractional anisotropy showed a significant positive correlation with age in the posterior caudate. There was significant negative correlation between dopamine synthesis capacity and mean diffusivity in the posterior caudate and putamen. Assuming that mean diffusivity reflects the density of wide-spreading axonal terminals in the striatum, the result suggests that dopamine synthesis may be related to the density of dopaminergic neuronal fibers. It is evident that PET/DTI combined measurements can contribute to investigations of the pathophysiology of neuropsychiatric diseases involving malfunction of dopaminergic neurons.
Induced pluripotent stem cells (iPSC) are a promising cell source for cartilage regenerative medicine; however, the methods for chondrocyte induction from iPSC are currently developing and not yet sufficient for clinical application. Here, we report the establishment of a fluorescent indicator system for monitoring chondrogenic differentiation from iPSC to simplify screening for effective factors that induce chondrocytes from iPSC. We generated iPSC from embryonic fibroblasts of Col2a1-EGFP transgenic mice by retroviral transduction of Oct4, Sox2, Klf4, and c-Myc. Among the 30 clones of Col2a1-EGFP iPSC we established, two clones showed high expression levels of embryonic stem cell (ESC) marker genes, similar to control ESC. A teratoma formation assay showed that the two clones were pluripotent and differentiated into cell types from all three germ layers. The fluorescent signal was observed during chondrogenic differentiation of the two clones concomitant with the increase in chondrocyte marker expression. In conclusion, Col2a1-EGFP iPSC are useful for monitoring chondrogenic differentiation and will contribute to research in cartilage regenerative medicine.
Osteoarthritis (OA) is the most prevalent form of arthritis and accounts for substantial morbidity and disability, particularly in the elderly. It is characterized by changes in joint structure including degeneration of the articular cartilage and its etiology is multifactorial with a strong postulated genetic component. We performed a meta-analysis of four genome-wide association (GWA) studies of 2,371 knee OA cases and 35,909 controls in Caucasian populations. Replication of the top hits was attempted with data from additional ten replication datasets. With a cumulative sample size of 6,709 cases and 44,439 controls, we identified one genome-wide significant locus on chromosome 7q22 for knee OA (rs4730250, p-value=9.2×10−9), thereby confirming its role as a susceptibility locus for OA. The associated signal is located within a large (500kb) linkage disequilibrium (LD) block that contains six genes; PRKAR2B (protein kinase, cAMP-dependent, regulatory, type II, beta), HPB1 (HMG-box transcription factor 1), COG5 (component of oligomeric golgi complex 5), GPR22 (G protein-coupled receptor 22), DUS4L (dihydrouridine synthase 4-like), and BCAP29 (the B-cell receptor-associated protein 29). Gene expression analyses of the (six) genes in primary cells derived from different joint tissues confirmed expression of all the genes in the joint environment.
Individual skeletal elements of the vertebrate limbs arise through a segmentation process introducing joints in specific locations. However, the molecular pathways controlling joint formation and subsequent joint maintenance are largely unknown. In this study, we focused on SOX11, and its contribution to the regulation of GDF5, a secreted signal necessary for proper joint formation and postnatal joint homeostasis.
Sox11 is initially expressed broadly in the murine cartilage condensations at early stages of skeletal development, but its expression is specifically increased in the forming joint interzone as is forms. SOX11 overexpression can directly activate GDF5 expression both in vitro and in micromass cell cultures prepared from chick limb buds. Conserved SOX family binding sites are present in the 5’ UTR region of the GDF5 gene and we show SOX11 can specifically bind to one of them. While misexpression of Sox11 in developing chick limbs through RCAS virus infection does not induce Gdf5 expression in ectopic locations, it does enhance its expression. To explore the roles of Sox11 in joint homeostasis, we analyzed adult knee joints in an osteoarthritis mouse model where the medial meniscus and the medial collateral ligament were removed. We also analyzed knee joints from human subjects who underwent total knee replacement surgery. We find that SOX11 is mainly expressed in the weight-bearing areas of knee joints, and its expression is decreased in degraded cartilage during progression of knee osteoarthritis in both mice and humans.
This work implicates SOX11 as a potential regulator of GDF5 expression in joint maintenance and suggests a possible role in the pathogenesis of osteoarthritis.
SOX11; GDF5; Joint maintenance; Articular cartilage
Objectives: The epithelial-mesenchymal-transition (EMT) is an important step in the invasion and metastasis of cancer. A critical molecular feature of this process is the downregulation of E-cadherin expression, which is mainly controlled by Snail-related zinc-finger transcription factors (Snail and Slug). The aim of this study was to evaluate the prognostic impact of EMT-related protein (E-cadherin, Snail and Slug) expression in endometrial cancer.
Methods: An immunohistochemical analysis was conducted using tissue microarray samples of 354 primary tumors and 30 metastases of endometrial carcinomas, and the relationship between protein expression, clinicopathological features and outcomes were investigated.
Results: Reduced E-cadherin was seen in 39.8% of primary tumors. Reduced E-cadherin was seen in 19.5%, 40.8% and 72.7% of G1, G2 and G3 endometrioid adenocarcinomas, respectively. The nuclear expression of Snail and Slug were positive in 16.9% and 3.7% of primary tumors, respectively. EMT status, which was represented by both reduced E-cadherin and nuclear expression of Snail, was significantly associated with histological type, FIGO stage, myometrial invasion, positive peritoneal cytology and patient survival (p < 0.01). There was no difference in the rates of EMT status between the primary tumors and metastases. A multivariate analysis showed that EMT-positive status was a significant predictor for both the progression-free survival and overall survival (p < 0.01).
Conclusions: These data indicate that EMT status has a prognostic impact in endometrial cancer. Therefore, the clarification and control of EMT signaling is a promising molecular targeting therapy in endometrial cancer.
epithelial-mesenchymal-transition; EMT; Snail; Slug; E-cadherin; endometrial cancer
Mature cystic teratomas (MCTs) are the most common germ cell tumors of the ovary. Malignant tranformation occurs in 1-2% of these neoplasms. Although most of the malignancies arising from MCTs are squamous cell carcinomas, adenocarcinoma of the gastrointestinal type is extremery rare. We herein present a case of adenocarcinoma of the intestinal type arising from a MCT.
A 49-year-old female underwent surgery for a left ovarian tumor. The histology of the cyst walls revealed a MCT with a few hair shafts and a squamous layer, while another part of the tumor showed adenocarcinoma of the intestinal type. Five years after surgery, she is alive without disease.
Malignant transformation; Mature cystic teratoma; Adenocarcinoma; Intestinal type
To determine whether mild cognitive impairment (MCI) increases the risk of occurrence or progression of radiographic knee osteoarthritis (KOA) in a general population.
Population-based cohort study.
Residents in mountain and seaside areas of Wakayama Prefecture, Japan.
1690 participants (596 men, 1094 women; mean age 65.2 years old) were enrolled from the large-scale cohort for the Research on Osteoarthritis (OA)/osteoporosis Against Disability (ROAD) study initiated in 2005 to investigate epidemiological features of OA in Japan. Of these, 1384 individuals (81.9%; 466 men, 918 women) completed the second survey including knee radiography 3 years later.
Primary outcome measures
Radiographic KOA was defined as Kellgren-Lawrence (KL) grade ≥ 2 using paired x-ray films. Incidence of KOA during follow-up defined on radiographs as KL grade ≥2, progression of KOA defined as a higher KL grade (either knee) at follow-up compared with baseline. MCI defined as a summary mini-mental state examination (MMSE) score ≤23. Associations between MCI and incidence or progression of KOA were analysed.
The annual cumulative incidence of KOA was 3.3%; for progression of OA it was 8.0%. On logistic regression analysis adjusted for age, gender, regional differences, body mass index, grip strength (worse side), smoking, alcohol consumption, regular exercise and history of knee injury, baseline MMSE summary score was significantly associated with the incidence of KOA (+1 MMSE score; OR 0.83, p=0.010). Baseline MCI was also significantly associated with the incidence of KOA (vs non-occurrence of KOA; OR 4.90, p=0.027). There was no significant association between MMSE scores, the presence of MCI and progression of KOA (+1 MMSE score; OR 0.96, p=0.232; vs non-progression of KOA; OR 1.38, p=0.416).
MCI significantly increases the risk of incident radiographic KOA, but not the progression of KOA.
G protein-coupled receptor 30 (GPR30) is a 7-transmembrane estrogen receptor that functions alongside traditional estrogen receptors to regulate the cellular responses to estrogen. Recent studies suggest that GPR30 expression is associated with a poor prognosis, and that this is due to the GPR30-mediated transactivation of the EGFR in breast cancer. However, the biological contribution of GPR30 in ovarian cancer remains unclear. The purpose of this study was to elucidate the relationships between GPR30 expression and the clinicopathological findings, and to determine how the signaling cascade influences the prognosis of ovarian cancer.
The expression levels of GPR30, EGFR, ERα, and ERβ were analyzed using an immunohistochemical analysis, and their correlations with the clinicopathological features were examined in 10 patients with borderline malignant tumors and 152 patients with epithelial ovarian cancer. We also examined whether GPR30 signaling activates the EGFR-Akt pathway in an ovarian cancer cell line (Caov-3) by a Western blotting analysis.
The GPR30 expression in ovarian carcinomas was significantly higher than that in borderline malignancies (p=0.0016), and was not associated with the expression of the EGFR, ERα, or ERβ. The expression of GPR30 in clear cell carcinomas was significantly lower than that in other subtypes of cancer (P <; 0.001). The expression of both GPR30 and EGFR was significantly associated with a poor prognosis in terms of the progression-free survival rate. The phosphorylation of the EGFR and Akt could be significantly enhanced by G1 (p <; 0.05) and inhibited by a Src family kinase inhibitor.
The expression of both GPR30 and EGFR is associated with a poor outcome in ovarian cancer, and GPR30 increases the phosphorylation of Akt via the EGFR in ovarian cancer cells. The regulation of GPR30 might be a potentially useful new therapeutic target in ovarian cancer.
G protein-coupled receptor 30; GPR30; 7-transmembrane estrogen receptor; EGFR; Akt; ERα; Clear cell carcinomas; Prognostic factor
Although general anesthesia is widely used in the surgical arena, the mechanisms by which general anesthetics act remain unclear. We previously described alterations in gene expression ratios in hepatic tissue taken from rats treated with anesthetics. Consequently, it is considered that anesthetics influence liver metabolism. Thus, the goal of this study was to use pattern recognition analysis of proton nuclear magnetic resonance spectra to visualize changes in liver metabolic phenotypes in response to widely used intravenous anesthetics (propofol and dexmedetomidine) and inhalational anesthetics (sevoflurane and isoflurane).
Rats were randomized into 13 groups (n = 6 in each group), and each group received one of following agents: propofol, dexmedetomidine, sevoflurane, isoflurane, or no anesthetic (control group). The liver was directly removed from rats immediately after or 24 h or 48 h after a 6-h period of anesthesia. Hydrophilic compounds were extracted from the liver and were analyzed with proton nuclear magnetic resonance spectroscopy. All spectral data were processed and analyzed by principal component analysis for comparison of metabolite profiles.
Data were visualized by plotting principal component (PC) scores. In the plots, each point represents an individual sample. Each group was clustered separately on the plots, and the PC scores of the propofol group were clearly distinct from those of the control group and other anesthetic groups. The difference in PC scores was more pronounced immediately after completion of anesthesia when compared with 24 or 48 h after completion of anesthesia. Although the effect of intravenous anesthetics on the liver dissipated over time, the effect of inhalational anesthetics persisted.
Propofol, dexmedetomidine, sevoflurane and isoflurane exert different effects on liver metabolism. In particular, liver metabolism was markedly altered after exposure to propofol. The effect of anesthesia on the liver under propofol or dexmedetomidine resolved rapidly when compared with the effect under sevoflurane or isoflurane.
Adequate modeling of light propagation in the head is important to predict the
sensitivity of NIRS signal and the spatial sensitivity profile of
source-detector pairs. The 3D realistic head models of which the geometry is
based upon the anatomical images acquired by magnetic resonance imaging and
x-ray computed tomography are constructed to investigate the influence of the
frontal sinus on the NIRS signal and spatial sensitivity. Light propagation in
the head is strongly affected by the presence of the frontal sinus. The light
tends to propagate around the frontal sinus. The influence of the frontal sinus
on the sensitivity of the NIRS signal to the brain activation is not consistent
and depends on the depth of the frontal sinus, the optical properties of the
superficial tissues and the relative position between the source-detector pair
and the frontal sinus. The frontal sinus located in the shallow region of the
skull tends to reduce the sensitivity of the NIRS signal while the deep frontal
sinus can increase the sensitivity of the NIRS signal.
(170.3660) Light propagation in tissues; (170.5280) Photon migration; (170.2655) Functional monitoring and imaging
In natural synovial joints under physiologic conditions, fluid thin-film lubrication by a hydrated layer of the cartilage is essential for the smooth motion of the joints. The considerably less efficient lubrication of artificial joints of polyethylene is prone to wear, leading to osteolysis and aseptic loosening and limiting the longevity of THA. A nanometer-scale layer of poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) with cartilage-mimicking brushlike structures on a crosslinked polyethylene (CLPE) surface may provide hydrophilicity and lubricity resembling the physiologic joint surface.
We asked whether the photoirradiation time during graft polymerization would affect the density and stability of the PMPC layer and the PMPC-grafted surface would enhance the durability of artificial joints. We investigated the effect of photoirradiation time and the resultant characteristics of the PMPC layer on the durability of the CLPE.
For each of the PMPC-grafted CLPE surfaces with various photoirradiation times (six groups: 0 [untreated CLPE], 11, 23, 45, 90, and 180 minutes), 18 sample pieces (total of 108 samples) were evaluated in surface analyses, and four cups (total of 24 samples) were evaluated in a hip simulator test.
The density of the PMPC layer increased with an increase in the photoirradiation time. The hip simulator test confirmed the PMPC-grafted CLPE with a high density of the PMPC layer exhibited minimal wear as compared with the untreated CLPE. High-density PMPC grafting appears essential for maintaining the high wear resistance of the PMPC-grafted CLPE. To obtain a high-density PMPC layer, the photoirradiation time must be greater than 45 minutes.
The cartilage-mimicking, density brushlike structure of the PMPC-grafted CLPE could extend high durability to acetabular cups in THA.
Our in vitro findings suggest the wear performance of CLPE acetabular cups in THA can be improved by this approach.
RUNX2 and SP7 are essential transcription factors for osteoblast differentiation at an early stage. Although RUNX2 inhibits osteoblast differentiation at a late stage, the function of SP7 at the late stage of osteoblast differentiation is not fully elucidated. Thus, we pursued the function of SP7 in osteoblast differentiation. RUNX2 induced Sp7 expression in Runx2−/− calvarial cells. Adenoviral transfer of sh-Sp7 into primary osteoblasts reduced the expression of Alpl, Col1a1, and Bglap2 and mineralization, whereas that of Sp7 reduced Bglap2 expression and mineralization at a late stage of osteoblast differentiation. Sp7 transgenic mice under the control of 2.3 kb Col1a1 promoter showed osteopenia and woven-bone like structure in the cortical bone, which was thin and less mineralized, in a dose-dependent manner. Further, the number of processes in the osteoblasts and osteocytes was reduced. Although the osteoblast density was increased, the bone formation was reduced. The frequency of BrdU incorporation was increased in the osteoblastic cells, while the expression of Col1a1, Spp1, Ibsp, and Bglap2 was reduced. Further, the osteopenia in Sp7 or Runx2 transgenic mice was worsened in Sp7/Runx2 double transgenic mice and the expression of Col1a1 and Bglap2 was reduced. The expression of Sp7 and Runx2 was not increased in Runx2 and Sp7 transgenic mice, respectively. The expression of endogenous Sp7 was increased in Sp7 transgenic mice and Sp7-transduced cells; the introduction of Sp7 activated and sh-Sp7 inhibited Sp7 promoter; and ChIP assay showed the binding of endogenous SP7 in the proximal region of Sp7 promoter. These findings suggest that SP7 and RUNX2 inhibit osteoblast differentiation at a late stage in a manner independent of RUNX2 and SP7, respectively, and SP7 positively regulates its own promoter.
To address the need for standardization of osteoarthritis (OA) phenotypes by examining the effect of heterogeneity among symptomatic (SOA) and radiographic osteoarthritis (ROA) phenotypes.
Descriptions of OA phenotypes of the 28 studies involved in the TREAT-OA consortium were collected. To investigate whether different OA definitions result in different association results, we created hip OA definitions used within the consortium in the Rotterdam Study-I and tested the association of hip OA with gender, age and BMI using one-way ANOVA. For radiographic OA, we standardized the hip, knee and hand ROA definitions and calculated prevalence's of ROA before and after standardization in 9 cohort studies. This procedure could only be performed in cohort studies and standardization of SOA definitions was not feasible at this moment.
In this consortium, all studies with symptomatic OA phenotypes (knee, hip and hand) used a different definition and/or assessment of OA status. For knee, hip and hand radiographic OA 5, 4 and 7 different definitions were used, respectively. Different hip OA definitions do lead to different association results. For example, we showed in the Rotterdam Study-I that hip OA defined as “at least definite JSN and one definite osteophyte” was not associated with gender (p=0.22), but defined as “at least one definite osteophyte” was significantly associated with gender (p=3×10−9). Therefore, a standardization process was undertaken for radiographic OA definitions. Before standardization a wide range of ROA prevalence's was observed in the 9 cohorts studied. After standardization the range in prevalence of knee and hip ROA was small. Standardization of SOA phenotypes was not possible due to the case-control design of the studies.
Phenotype definitions influence the prevalence of OA and association with clinical variables. ROA phenotypes within the TREAT-OA consortium were standardized to reduce heterogeneity and improve power in future genetics studies.
Bcl2 subfamily proteins, including Bcl2 and Bcl-XL, inhibit apoptosis. As osteoblast apoptosis is in part responsible for osteoporosis in sex steroid deficiency, glucocorticoid excess, and aging, bone loss might be inhibited by the upregulation of Bcl2; however, the effects of Bcl2 overexpression on osteoblast differentiation and bone development and maintenance have not been fully investigated. To investigate these issues, we established two lines of osteoblast-specific BCL2 transgenic mice. In BCL2 transgenic mice, bone volume was increased at 6 weeks of age but not at 10 weeks of age compared with wild-type mice. The numbers of osteoblasts and osteocytes increased, but osteoid thickness and the bone formation rate were reduced in BCL2 transgenic mice with high expression at 10 weeks of age. The number of BrdU-positive cells was increased but that of TUNEL-positive cells was unaltered at 2 and 6 weeks of age. Osteoblast differentiation was inhibited, as shown by reduced Col1a1 and osteocalcin expression. Osteoblast differentiation of calvarial cells from BCL2 transgenic mice also fell in vitro. Overexpression of BCL2 in primary osteoblasts had no effect on osteoclastogenesis in co-culture with bone marrow cells. Unexpectedly, overexpression of BCL2 in osteoblasts eventually caused osteocyte apoptosis. Osteocytes, which had a reduced number of processes, gradually died with apoptotic structural alterations and the expression of apoptosis-related molecules, and dead osteocytes accumulated in cortical bone. These findings indicate that overexpression of BCL2 in osteoblasts inhibits osteoblast differentiation, reduces osteocyte processes, and causes osteocyte apoptosis.
Leg pain/numbness and gait disturbance, two major symptoms in the lower extremities of lumbar spinal stenosis (LSS), are generally expected to be alleviated by decompression surgery. However, the paucity of information available to patients before surgery about specific predictors has resulted in some of them being dissatisfied with the surgical outcome when the major symptoms remain after the procedure. This prospective, observational study sought to identify the predictors of the outcome of a decompression surgery: modified fenestration with restorative spinoplasty. Of 109 consecutive LSS patients who underwent the decompression surgery, 89 (56 males and 33 females) completed the 2 year follow-up. Both leg pain/numbness and gait disturbance determined by the Japanese Orthopedic Association scoring system were significantly improved at 2 years after surgery compared to those preoperative, regardless of potential predictors including gender, preoperative presence of resting numbness in the leg, drop foot, cauda equina syndrome, degenerative spinal deformity or myelographic filling defect, or the number of decompressed levels. However, 27 (30.3%) and 13 (14.6%) patients showed residual leg pain/numbness and gait disturbance, respectively. Among the variables examined, the preoperative resting numbness was associated with residual leg pain/numbness and gait disturbance, and the preoperative drop foot was associated with residual gait disturbance, which was confirmed by logistic regression analysis after adjustment for age and gender. This is the first study to identify specific predictors for these two remaining major symptoms of LSS after decompression surgery, and consideration could be given to including this in the informed consent.
Lumbar spinal stenosis; Decompression surgery; Outcome; Predictor
A retrospective study was performed to determine the sensitivities of the pyramidal signs in patients with cervical myelopathy, focusing on those with increased signal intensity (ISI) in T2-weighted magnetic resonance imaging (MRI). The relationship between prevalence of the pyramidal signs and the severity of myelopathy was investigated. We reviewed the records of 275 patients with cervical myelopathy who underwent surgery. Of these, 143 patients were excluded from this study due to comorbidities that might complicate neurological findings. The MR images of the remaining 132 patients were evaluated in a blinded fashion. The neurological findings of 120 patients with ISI (90 men and 30 women; mean age 61 years) were reviewed for hyperreflexia (patellar tendon reflex), ankle clonus, Hoffmann reflex, and Babinski sign. To assess the severity of myelopathy, the motor function scores of the upper and lower extremities for cervical myelopathy set by the Japanese Orthopaedic Association (m-JOA score) were used. The most prevalent signs were hyperreflexia (94%), Hoffmann reflex (81%), Babinski sign (53%), and ankle clonus (35%). Babinski sign (P < 0.001), ankle clonus, and Hoffmann reflex showed significant association with the lower m-JOA score. Conversely, no association was found with the upper m-JOA score. In patients with cervical myelopathy, hyperreflexia showed the highest sensitivity followed by Hoffmann reflex, Babinski sign, and ankle clonus. The prevalence of the pyramidal signs correlated with increasing severity of myelopathy. Considering their low sensitivity in patients with mild disability, the pyramidal signs may have limited utility in early diagnosis of cervical myelopathy.
Neurological examination; Babinski sign; Hoffmann reflex; Clonus; Pyramidal sign; Long tract sign