A Dof-CLE circuit controls phloem organization.

The phloem consists of sieve elements (SEs) and companion cells (CCs). Here we show that Dof-class transcription factors preferentially expressed in the phloem (phloem-Dofs) are not only necessary and sufficient for SE and CC differentiation, but also induce negative regulators of phloem development, CLAVATA3/EMBRYO SURROUNDING REGION-RELATED25 (CLE25), CLE26 and CLE45 secretory peptides. CLEs were perceived by BARELY ANY MERISTEM (BAM)-class receptors and CLAVATA3 INSENSITIVE RECEPTOR KINASE (CIK) co-receptors, and post-transcriptionally decreased phloem-Dof proteins and repressed SE and CC formation. Multiple mutations in CLE-, BAM- or CIK-class genes caused ectopic formation of SEs and CCs, producing an SE/CC cluster at each phloem region. We propose that while phloem-Dofs induce phloem cell formation, they inhibit excess phloem cell formation by inducing CLEs. Normal-positioned SE and CC precursor cells appear to overcome the effect of CLEs by reinforcing the production of phloem-Dofs through a positive feedback transcriptional regulation.

[The effect of routine professional oral care on oral mucositis in hematologic chemotherapy patients].

BACKGROUND: According to the literature, 40%of all oral complications associated with chemotherapy are due to oral mucositis. Moreover, such complications increase the difficulties associated with oral intake, leading to deterioration of the patient's nutritional condition and increasing the risk of systemic infection. Therefore, oral mucositis prevention and proper treatment are very important. PATIENTS AND METHODS: The conditions of intra-oral cavities and effects of oral care in patients with hematological malignancies were retrospectively evaluated by dental hygienists from April 2008 to March 2011. RESULTS: Eleven of 28 patients(39.3%)who received routine professional oral care developed oral mucositis. In many such patients, intra-oral cavity deterioration, evidenced by a coated tongue and Candida infection, was observed. Although 25 of 28 patients with hematologic malignancies received specific oral mucositis care after chemotherapy initiation, those receiving continuous oral care subsequently made a full recovery. CONCLUSIONS: These results suggest that early and continuous professional oral health care may play an important role in the effective chemotherapy of patients with hematologic malignancies.

Airway management for patients with ossification of the anterior longitudinal ligament of the cervical spine.

Ossification of the anterior longitudinal ligament (OALL), also called Forestier's disease or diffuse idiopathic skeletal hyperostosis, is characterized by anterior bridging osteophytes of unknown etiology. OALL may cause dysphagia, dyspnea, dysphonia, and acute airway obstruction. We report difficulty in tracheal intubation during anesthesia induction in two OALL patients. In an 82-year-old man, anterior bridging osteophytes (of the cervical region) were observed on preoperative lateral radiograph after several attempts of tracheal intubation for the operation of the anterior fusion of cervical spine. During the same procedure in another 69-year-old man, fiberoptic-assisted awake intubation was extremely difficult because of posterior hypopharyngeal wall protuberance by osteophytes of cervical spine; although tracheal intubation for anesthesia was uneventful on two previous occasions over the months. OALL is usually asymptomatic, but it has been found in 12 % of autopsies and may exaggerate with age. Dysphagia, difficulties with tracheal and/or gastric intubation, acute respiratory compromise, and sleep apnea result from the presence of cervical osteophytes. Anesthesiologists should be aware that tracheal intubation for such patients may be difficult, and thus the preoperative evaluation and airway management need careful consideration.

Differential effects of intravenous anesthetics on PDGF-BB-induced vascular smooth muscle cell migration.

BACKGROUND: Intravenous anesthetics are used during the perioperative and/or postoperative period in critically ill patients. Vascular smooth muscle cells (VSMCs) play important roles in vascular injury repair or restenosis after intervention. We previously reported that platelet-derived growth factor (PDGF)-BB induces VSMC migration via extracellular signal-regulated kinase (ERK) and Akt in a VSMC line, A10 cells. In the present study, we investigated the effects of intravenous anesthetics on PDGF-BB-induced VSMC migration and the mechanism. METHODS: VSMCs migration was assessed using Boyden chamber, and phosphorylation of each protein kinase was analyzed by Western blotting. RESULTS: Propofol or midazolam but not ketamine or dexmedetomidine suppressed PDGF-BB-induced A10 cells migration in a concentration-dependent manner. The suppressive effects on migration were observed also in human aortic smooth muscle cells. Propofol or midazolam did not affect phosphorylation of PDGF receptor ß in A10 cells. Propofol or midazolam failed to affect PDGF-BB-induced phosphorylation of ERK or Akt. On the other hand, propofol or midazolam attenuated PDGF-BB-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK), but did not affect phosphorylation of stress-activated protein kinase/c-Jun N-terminal kinase. Both ketamine and dexmedetomidine had no effect on the phosphorylation of p38 MAPK induced by PDGF-BB. CONCLUSION: These results strongly suggest that propofol or midazolam inhibits VSMC migration by PDGF-BB via suppression of p38 MAPK activation. Propofol or midazolam may affect VSMC function in critically ill patients.

Adenosine monophosphate-activated protein kinase regulates platelet-derived growth factor-BB-induced vascular smooth muscle cell migration.

Migration of vascular smooth muscle cells (VSMCs) is essential for repair of vascular injury, development of atherosclerotic lesions and restenosis after angioplasty or by-pass graft surgery. It has been reported that platelet-derived growth factor (PDGF)-BB induces VSMC migration via the p44/p42 mitogen-activated protein (MAP) kinase pathway and the phosphatidylinositol 3 (PI3)-kinase/Akt pathway. Adenosine monophosphate-activated protein kinase (AMPK) is generally known to regulate multiple metabolic pathway. In the present study, we investigated the involvement of AMPK in PDGF-BB-induced migration of VSMCs using, a VSMC line, A10 cells. PDGF-BB induced phosphorylation of AMPK-α at Thr-172 residue. Treatment of A10 cells with compound C, an AMPK inhibitor, suppressed PDGF-BB-induced migration in a concentration-dependent manner (0.01-1µM). Compound C truly attenuated PDGF-BB induced phosphorylation of acetyl-CoA carboxylase, a downstream substance of AMPK. Downregulation of AMPK-α expression by the siRNA appeared an anti-migratory effect on PDGF-BB-induced migration. PDGF-BB-induced phosphorylation of c-Raf, MEK1/2 or p44/p42 MAP kinase, and phosphorylation of PI3-kinase or Akt were markedly suppressed by compound C. In conclusion, our results strongly suggest that PDGF-BB induces activation of AMPK in VSMCs, and subsequently regulates the migration via both the p44/p42 MAP kinase pathway and the PI3-kinase/Akt pathway.

Involvement of phosphatidylinositol 3-kinase/Akt on basic fibroblast growth factor-induced glial cell line-derived neurotrophic factor release from rat glioma cells.

Basic fibroblast growth factor (FGF-2) has a neuroprotective effect. Astrocytes support neurons by releasing neurotrophic factors including glial cell line-derived neurotrophic factor (GDNF). FGF-2 stimulates GDNF synthesis in astrocytes and the release. It has been reported that FGF-2 induces the activation of p44/p42 mitogen-activated protein (MAP) kinase, stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) and p38 MAP kinase in C6 glioma cells, and that FGF-2 stimulates GDNF release through p44/p42 MAP kinase or SAPK/JNK, but not p38 MAP kinase. In the present study, we investigated the exact mechanism of FGF-2-induced GDNF release from C6 cells. FGF-2 induced the phosphorylation of Akt and its substrate, glycogen synthase kinase 3ß (GSK3ß) in addition to three MAP kinases in these cells. FGF-2-stimulated release of GDNF was suppressed by wortmannin (a phosphatidylinositol 3 (PI3)-kinase inhibitor) or LY294002 (another PI3-kinase inhibitor). The FGF-2-induced GDNF release from PI3-kinase-downregulated C6 cells was decreased compared with that in control siRNA-transfected cells. PD98059 (an inhibitor of MEK 1/2) or SP600125 (an inhibitor of SAPK/JNK), which suppressed FGF-2-induced phosphorylation of p44/p42 MAP kinase or SAPK/JNK respectively, did not affect FGF-2-induced Akt phosphorylation. Wortmannin or LY294002, which attenuated FGF-2-induced phosphorylation of Akt and GSK3ß, had no effect on FGF-2-induced phosphorylation of p44/p42 MAP kinase or SAPK/JNK. These results strongly suggest that the PI3-kinase/Akt pathway plays a positive role in FGF-2-stimulated GDNF release independently of p44/p42 MAP kinase or SAPK/JNK in C6 glioma cells.

Case report: central venous catheterization via internal jugular vein with associated formation of perioperative venous thrombosis during surgery in the prone position.

An unusual case of central venous catheter (CVC)-related thrombosis during supine surgery in the prone position is presented. A 76-year-old woman was scheduled for elective surgery to repair a broken lumbar instrument. A single-lumen CVC was inserted via the right internal jugular vein. Surgery was performed in the prone position, with the patient's face directed downward in the standard median position (i.e., no rotation), but with slight forward flexion at the neck. After the surgery, the external jugular vein was dilated, and a postoperative X-ray revealed an infiltrative shadow in the right thoracic cavity. Because cervical echography showed dilated cervical veins with a "moyamoya-type" echo, possibly indicating a thrombus, contrast-enhanced computed tomography was performed, revealing a venous thrombus in the right internal jugular vein. An internal jugular venous-velocity measurement suggested that her slightly flexed neck position and her prone position during surgery may have kinked the internal jugular vein, causing engorgement with venous blood. The presence of the internal jugular venous catheter may have created thrombogenic conditions. A patient's position during surgery can reduce deep venous-flow velocity, and venous blood may stagnate, contributing greatly to thrombogenicity. We should consider a patient's position during surgery as a risk factor for thrombus formation, and a careful preoperative evaluation should be made as to which route should be chosen for CVC.