Collaborative action of M-CSF and CTGF/CCN2 in articular chondrocytes: possible regenerative roles in articular cartilage metabolism

It is known that expression of the macrophage colony-stimulating factor (M-CSF) gene is induced in articular chondrocytes upon inflammation. However, the functional role of M-CSF in cartilage has been unclear. In this study, we describe possible roles of M-CSF in the protection and maintenance of the articular cartilage based on the results of experiments using human chondrocytic cells and rat primary chondrocytes. Connective tissue growth factor (CTGF/CCN2) is known to be a potent molecule to regenerate damaged cartilage by promoting the growth and differentiation of articular chondrocytes. Here, we uncovered the fact that M-CSF induced the mRNA expression of the ctgf/ccn2 gene in those cells. Enhanced production of CTGF/CCN2 protein by M-CSF was also confirmed. Furthermore, M-CSF could autoactivate the m-csf gene, forming a positive feed-back network to amplify and prolong the observed effects. Finally, promotion of proteoglycan synthesis was observed by the addition of M-CSF. These findings taken together indicate novel roles of M-CSF in articular cartilage metabolism in collaboration with CTGF/CCN2, particularly during an inflammatory response. Such roles of M-CSF were further supported by the distribution of M-CSF producing chondrocytes in experimentally induced rat osteoarthritis cartilage in vivo.     

Left thoracotomy approach in reoperative off-pump coronary revascularization

Objective: Reoperative coronary bypass grafting is at high risk. Particularly in redo cases where the patent graft is running near the midline of the sternum, the graft may be exposed to injury by a median sternotomy and subsequent dissection. Whereas, off-pump bypass grafting from the left axillary artery or descending thoracic artery by a left thoracotomy approach is safe for preventing graft damage.Methods: From March 1998 to February 2002, we performed off-pump coronary artery bypass grafting by a left thoracotomy approach in 9 patients. The left axillary artery was used as the inflow vessel in 4 cases, and the descending thoracic, aorta in 5.Results: The radial artery was anastomosed proximally to the axillary artery in 4 cases and the descending thoracic aorta in one case. The saphenous vein graft was anastomosed, proximally to the descending thoracic aorta in 4 cases. Transdiaphragmatic minimally invasive bypass grafting for the right coronary artery was simultaneously performed in 3 cases. Postoperative cardiac events were ventricular arrhythmia in 6 cases and supraventricular arrhythmia in 3 cases. There was no damage to the patent grafts. Postoperative coronary angiography performed, in 8 cases revealed all the grafts to be patent without stenosis. Cardiac symptoms were not found after the operation in any of the cases.Conclusions: These procedures can prevent the injury to patent grafts caused by a median sternotomy, and will be one of the useful strategies for reoperative off-pump coronary artery bypass grafting.     

Glycosaminoglycan and proteoglycan inhibit the depolymerization of beta2-microglobulin amyloid fibrils in vitro

BACKGROUND: Although several kinds of evidence suggest that glycosaminoglycans (GAGs) and proteoglycans (PGs) may contribute to the development of beta2-microglobulin-related (Abeta2m) amyloidosis, the precise roles of these molecules for the development of Abeta2m amyloidosis are poorly understood. METHODS: We investigated the effects of GAGs and PGs on the depolymerization of Abeta2m amyloid fibrils at a neutral pH, as well as on the formation of the fibrils at an acidic pH in vitro, using fluorescence spectroscopy with thioflavin T and electron microscopy. RESULTS: Depolymerization of Abeta2m amyloid fibrils at pH 7.5 at 37 degrees C was inhibited dose-dependently by the presence of some GAGs (heparin, dermatan sulfate, or heparan sulfate) or PGs (biglycan, decorin, or keratan sulfate proteoglycan). Electron microscopy revealed that a significant amount of Abeta2m amyloid fibrils remained in the reaction mixture with some lateral aggregation. Second, when monomeric beta2m was incubated with aggrecan, biglycan, decorin, or heparin at pH 2.5 at 37 degrees C for up to 21 days, the thioflavin T fluorescence increased depending on dose and time. Electron microscopy revealed the formation of rigid and straight fibrils similar to Abeta2m amyloid fibrils in beta2m incubated with biglycan for 21 days. CONCLUSION: These results suggest that some GAGs and PGs could enhance the deposition of Abeta2m amyloid fibrils in vivo, possibly by binding directly to the surface of the fibrils and stabilizing the conformation of beta2m in the fibrils, as well as by acting as a scaffold for the polymerization of beta2m into the fibrils.     

Bilateral carotid stenting for bilateral carotid artery stenosis improved vascular dementia

We report a case of bilateral internal carotid artery (ICA) stenosis treated with stenting. A 78-year-old man suffered from vascular dementia and left hemiparesis, and, by magnetic resonance angiogram (MRA), was diagnosed as having bilateral ICA stenosis. Cerebral angiogram showed severe, bilateral ICA stenosis (right; 88%, left; 93%) and xenon single photon emission tomography (SPECT) showed severely decreased cerebral blood flow (CBF) and cerebrovascular reactivity (CVR). We performed bilateral carotid angioplasty with self-expanding stents. Both CBF and CVR were improved bilaterally after the operation. The patient was discharged without neurological deficits. Carotid stenting may be an alternative treatment for severe ischemia caused by severe, bilateral ICA stenosis.     

Comparison in prognosis after VATS lobectomy and open lobectomy for stage I lung cancer

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) has become an attractive surgical procedure, but several issues remain to be resolved. Prognosis after VATS lobectomy is important to evaluate the adequacy of VATS lobectomy as a cancer operation. Interestingly, several investigators, including us, have reported that prognosis after VATS lobectomy was superior to that after open lobectomy in early non-small-cell lung cancer (NSCLC). One of the possible reasons is the low invasiveness of VATS lobectomy. But we considered that patient bias might have some influence favoring VATS lobectomy. To evaluate our hypothesis, we reviewed medical records of stage I NSCLC patients undergoing operation between 1993 and 2002. We compared and evaluated the relationship between patient characteristics and prognosis after VATS and open lobectomy. We focused particularly on histological type, classifying it into four subgroups; (1) bronchioloalveolar carcinoma (BAC), (2) mixed BAC + papillary adenocarcinoma (BAC + Pap), (3) other adenocarcinoma (Other adeno), (4) squamous cell carcinoma + others (Sq + others). RESULTS: A total of 165 patients underwent VATS lobectomy, and 123 patients underwent open lobectomy. The 5-year survival rate of the VATS lobectomy group was 94.5% and that of the open lobectomy group was 81.5%. Univariate Cox regression of survival revealed that male, CEA > 5, Other adeno, Sq + others, open lobectomy, and tumor size > 3 cm were significant negative prognostic variables. Multivariate Cox regression of survival revealed that histological subtype and tumor size were independent prognostic factors, but surgical procedure was not an independent prognostic factor. COMMENTS: Prognosis after VATS lobectomy was superior to that after open lobectomy, but patient bias influenced the prognosis in favor of VATS lobectomy, and the surgical procedure itself was not a prognostic factor.     

Ultraflex expandable stents for the management of air leaks.

Postoperative empyema and aspergillosis were diagnosed in a 66-year-old man. Since non-operative therapy was not effective, we performed surgery. On the 8th postoperative day, a covered Ultraflex expandable stent (Boston Scientific, Galway, Ireland) was implanted to make a one-way airway for blocking a major air leak from a bronchopleural fistula causing respiratory distress. His general condition improved gradually, and he was discharged 30 days after stenting. In conclusion, we used a covered Ultraflex expandable stent to make an airway to block an air leak. This may be a new application for this stent.     

Roles of Carbon Monoxide in Leukocyte and Platelet Dynamics in Rat Mesentery during Sevoflurane Anesthesia

Background: Heme oxygenase 1 (HO-1), induced by a variety of stressors, provides endogenous carbon monoxide (CO) and bilirubin, both of which play consequential roles in organs. The current study aimed to examine whether induction of HO-1 and its by-products modulated endothelial interaction with circulating leukocytes and platelets evoked by sevoflurane anesthesia in vivo.

Methods: Rats, pretreated with or without hemin, were anesthetized with sevoflurane in 100% O2, and lungs were mechanically ventilated. Platelets labeled with carboxyfluorescein diacetate succinimidyl ester and leukocyte behavior in mesenteric venules were visualized during sevoflurane anesthesia at 1,000 frames/s using intravital ultrahigh-speed intensified fluorescence videomicroscopy. To examine the mechanisms for the effects of HO-1 on leukocyte and platelet behavior, these studies were repeated with superfusion of either CO, bilirubin, or N[omega]-nitro-l-arginine methyl ester (l-NAME).

Results: As reported previously, the elevation of sevoflurane concentration evoked adhesive responses of leukocytes, concurrent with platelet margination and rolling. Pretreatment with hemin, a HO-1 inducer, prevented such sevoflurane-elicited changes in the microvessels. These changes were restored by zinc protoporphyrin IX, a HO inhibitor, and repressed by CO but not by bilirubin. During sevoflurane anesthesia, however, nitric oxide suppression by l-NAME deteriorated microvascular flows irrespective of the presence or absence of the HO-1 induction.     

Levofloxacin alone efficiently treated a cutaneous mycobacterium fortuitum infection

Cutaneous infections with Mycobacterium (M.) fortuitum are rare, and some cases resist treatment. We report two cases of cutaneous M. fortuitum infection successfully treated with levofloxacin alone.     

Granulocyte-macrophage colony stimulating factor inhibits class II major histocompatibility complex expression and antigen presentation by microglia

Granulocyte-macrophage colony stimulating factor (GM-CSF) modulates various functions of monocytes/ macrophages including antigen-presenting capacity. Recently it was found that astrocytes produce GM-CSF in the central nervous system (CNS) and that GM-CSF can induce proliferation and morphological changes of microglia. Here we show that GM-CSF can down regulate the interferon-γ-mediated induction of major histocompatibility complex (MHC) class II antigens in microglia, but not in astrocytes. GM-CSF pretreatment completely prevents myelin basic protein-specific T cell proliferation induced by microglia but not astrocytes. GM-CSF did not affect the cell surface expression on microglia of either MHC class I or cell adhesion molecules. The inhibition of microglial MHC class II expression and antigen-presenting function is specific for GM-CSF, as treatment with a different CSF (interleukin-3) did not modulate microglial phenotype or functional capacity. These data suggest that GM-CSF might be involved in the regulation of immune responses within the central nervous system.     

Possibility of ideal blood glucose control by a new oral hypoglycemic agent, N-[(trans-4-isopropylcyclohexyl)-carbonyl]-D-phenylalanine (A-4166), and its stimulatory effect on insulin secretion in animals

N-[(trans-4-isopropylcyclohexyl)-carbonyl]-D-phenylalanine (A-4166) revealed a new mode of hypoglycemic action with a more rapid onset and a shorter duration of action than the sulfonylureas (SUs). Hypoglycemic mechanisms and glycemic control benefits were demonstrated in laboratory animals. The stimulatory effect of A-4166 on insulin release, in fasting dogs with a cannula into the portal vein, was more rapid than that of tolbutamide after oral administration. A-4166 stopped the stimulation of insulin secretion very quickly, whereas tolbutamide maintained an elevation in plasma insulin levels for at least 6 hours. In the case of A-4166, a counter-regulatory glucagon response was observed during recovery from hypoglycemia, but it was significantly inhibited by tolbutamide. Hyperglycemia induced by glucose loading was rapidly inhibited by A-4166 in normal rats, in genetically diabetic KK mice and in STZ-induced non-insulin-dependent diabetes mellitus (NIDDM) rats. Also, repeated administration of A-4166 for 2 weeks enhanced insulin secretion in the same manner as a single administration in normal rats. In conclusion, A-4166 is a new type of oral hypoglycemic agent, having a rapid and short-term insulin secretory effect and no suppressive effect on the hypoglycemia-induced glucagon response. Oral therapy with A-4166 would be beneficial in supplementing endogenous insulin secretion and would exert ideal glycemic control in NIDDM patients.