Settlement of Stenotic Site and Enhancement of Risk Factor Load for Atherosclerosis in Left Anterior Descending Coronary Artery by Myocardial Bridge.

OBJECTIVE: The aim of this study was to investigate the influence of a myocardial bridge (MB) on atherosclerosis development in the left anterior descending artery of the normal heart and the importance of traditional risk factors (RFs). An additional objective was to determine the correlation between intimal thickening and luminal narrowing. APPROACH AND RESULTS: The left anterior descending artery from 150 autopsied hearts was treated with formalin perfusion fixation, and each left anterior descending artery was serially cross-sectioned. The intima-media and luminal stenosis ratios were examined using computer-assisted histomorphometry. The luminal stenosis ratio was closely correlated with the intima-media ratio (r=0.792; P<0.001). When an MB was present, the luminal stenosis ratios proximal to the MB in the RF (+) group were significantly greater than those in the RF (-) group (P=0.022 by a multiple comparison test), but there were no differences between the RF (+) and RF (-) groups when an MB was absent. In addition, the site of the greatest stenosis in the MB (+) RF (+) group was 2.5 cm proximal to the MB entrance. Multivariate analyses indicated that age was an independent factor for luminal stenosis ratios ≥50% and 60% (P=0.002 and 0.029, respectively). Furthermore, the presence of an MB plus RFs was an independent factor for a luminal stenosis ratio ≥70% (P=0.037). CONCLUSIONS: An MB enhances left anterior descending artery atherosclerosis development at a site proximal to the MB entrance, particularly in subjects who have some RFs.

Differences between gastric signet-ring cell carcinoma and poorly differentiated adenocarcinoma: A comparison of histopathologic features determined by mucin core protein and trefoil factor family peptide immunohistochemistry.

We investigated differences between the pathological features of gastric signet-ring cell carcinoma (sig) and poorly differentiated adenocarcinoma (por) by examining the expressions of the trefoil factor family peptides (TFFs) and mucin core proteins (MUCs). Ninety-seven tissues of 97 gastric cancer patients were selected for this study. After gastrectomy, the major histopathologic types were determined to be sig, solid-type poorly differentiated adenocarcinoma (por1), non-solid type poorly differentiated adenocarcinoma (por2), and well-differentiated tubular adenocarcinoma (tub1). We evaluated the prevalence of positive staining for MUCs (MUC5AC and MUC2) and TFFs (TFF1 and TFF3) and assessed the correlation between MUCs and TFFs in each histopathological type. The rate of MUC2 expression significantly differed between sig and por2 (50.0% vs 11.7%, P = 0.011). TFF3 expression in sig significantly differed from TFF3 expression in both por2 (100% vs 17.6%, P < 0.0001) and por1 (100% vs 33.3%, P = 0.0004). MUC5AC and TFF1 expressions were significantly correlated in por1 (r = 0.705, P = 0.002), por2 (r = 0.535, P = 0.0009), and tub1 (r = 0.470, P = 0.0034), while MUC2 and TFF3 expressions were significantly correlated only in sig (r = 0.593, P = 0.040). The expression and correlation patterns of the TFFs and MUCs suggest that the histopathologic features of gastric sig differ from those of por.

Protective effect of procysteine on Acinetobacter pneumonia in hyperoxic conditions.

OBJECTIVES: Ventilator-associated pneumonia (VAP) is an important cause of morbidity and mortality in critical care settings. Acinetobacter has become a leading cause of VAP. In particular, the appearance and spread of multidrug-resistant Acinetobacter is of great concern. In this study, we examined the effect of the antioxidant procysteine on Acinetobacter murine pneumonia in hyperoxic conditions in order to simulate VAP. METHODS: Acinetobacter was administered intranasally to BALB/c mice kept in hyperoxic conditions. At designated timepoints, bacterial number, cytokine production and histopathological findings in the lungs were examined. The effects of procysteine on survival rates, lung bacterial burdens and the phagocytic activities of alveolar macrophages were evaluated. RESULTS: Drastic decreases in survival were observed when the infected mice were kept in hyperoxic conditions (P < 0.001). Significant differences in pulmonary bacterial number and neutrophil accumulation were observed between mice kept in hyperoxic or normoxic conditions on day 3. Although all mice infected with Acinetobacter spp. and kept in hyperoxic conditions died by day 3, procysteine treatment significantly improved survival (60% survival on day 7, P < 0.01). Procysteine treatment decreased the lung bacterial burden on days 2 and 3. Finally, improved uptake of FITC-labelled beads by alveolar macrophages from mice treated with procysteine and kept in hyperoxic conditions was noted. CONCLUSIONS: These results suggest that hyperoxia increases mortality in mice with Acinetobacter pneumonia and that procysteine improves survival by increasing the phagocytic activity of alveolar macrophages in mice kept in hyperoxic conditions.

Effects of slow-releasing colistin microspheres on endotoxin-induced sepsis.

Lipopolysaccharide (LPS) is a major contributing factor to endotoxic shock. Colistin specifically binds to LPS. However, it has the disadvantages that adverse reactions are common and it has a short half-life. To overcome these disadvantages, we prepared slow-releasing colistin microspheres and examined the efficacy of these colistin microspheres in a mouse model of endotoxin-induced sepsis. We prepared the colistin microspheres using poly-lactic-co-glycolic acid. For acute toxicity investigations, mice were overdosed with colistin sulfate or colistin microspheres. The group administered with colistin microspheres was associated with less acute toxicity and fewer nephrotoxic changes on histopathological examination compared to the group administered with colistin sulfate alone. For pharmacokinetic analysis, mice were subcutaneously administered with colistin microspheres or colistin sulfate alone. The plasma concentration of colistin was higher in the colistin microspheres group than in the colistin sulfate group at 12 and 24 h after administration. Moreover, mice were intraperitoneally injected with LPS and then immediately subcutaneously administered with blank microspheres, colistin microspheres or colistin sulfate alone. The levels of endotoxin in the sera and cytokine in the spleens were then measured. A significant reduction in the serum endotoxin level in the colistin microspheres group was observed at 24 h. The reduced endotoxin levels in the sera were correlated with the lower cytokine levels in the spleens of mice treated with colistin microspheres. Our results suggest that the use of colistin microspheres may help to maintain a higher colistin concentration in blood, reduce the levels of endotoxin and cytokines in endotoxin-induced sepsis, and lead to decreased toxicity.

Irradiation Attenuates Systemic Lupus Erythematosus-Like Morbidity in NZBWF1 Mice: Focusing on CD180-Negative Cells.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of autoantibodies that can induce systemic inflammation. Ultraviolet-A and X-ray irradiation have been reported to have therapeutic effects in patients with SLE. We previously demonstrated that CD180-negative cells, these are radiosensitive, contribute to the development of SLE-like morbidity in NZBWF1 mice. In this study, the effects of irradiation on SLE-like morbidity manifestations in NZBWF1 mice and on CD180-negative cells were investigated. Whole-body irradiation, excluding the head, attenuated SLE-like morbidity in vivo, as indicated by the prevention of the renal lesion development, inhibition of anti-dsDNA antibody production, reduction of urinary protein levels, and prolongation of the lifespan. Irradiation also reduced the proportion of CD180-negative cells in the spleen. Although other immune cells or molecules may be triggered because of the whole-body irradiation treatment, previous research, and the current results suggest a strong relationship between the radiation-induced decrease in CD180-negative cells and the amelioration of SLE-like morbidities. Clinical trials assessing CD180-negative cells as a therapeutic target for SLE have been hampered by the lack of validated cell markers; nonetheless, the present findings suggest that radiotherapy may be a new therapeutic strategy for managing SLE symptoms.

Physiological roles of group X-secreted phospholipase A2 in reproduction, gastrointestinal phospholipid digestion, and neuronal function.

Although the secreted phospholipase A(2) (sPLA(2)) family has been generally thought to participate in pathologic events such as inflammation and atherosclerosis, relatively high and constitutive expression of group X sPLA(2) (sPLA(2)-X) in restricted sites such as reproductive organs, the gastrointestinal tract, and peripheral neurons raises a question as to the roles played by this enzyme in the physiology of reproduction, digestion, and the nervous system. Herein we used mice with gene disruption or transgenic overexpression of sPLA(2)-X to clarify the homeostatic functions of this enzyme at these locations. Our results suggest that sPLA(2)-X regulates 1) the fertility of spermatozoa, not oocytes, beyond the step of flagellar motility, 2) gastrointestinal phospholipid digestion, perturbation of which is eventually linked to delayed onset of a lean phenotype with reduced adiposity, decreased plasma leptin, and improved muscle insulin tolerance, and 3) neuritogenesis of dorsal root ganglia and the duration of peripheral pain nociception. Thus, besides its inflammatory action proposed previously, sPLA(2)-X participates in physiologic processes including male fertility, gastrointestinal phospholipid digestion linked to adiposity, and neuronal outgrowth and sensing.

Hair follicular expression and function of group X secreted phospholipase A2 in mouse skin.

Although perturbed lipid metabolism can often lead to skin abnormality, the role of phospholipase A(2) (PLA(2)) in skin homeostasis is poorly understood. In the present study we found that group X-secreted PLA(2) (sPLA(2)-X) was expressed in the outermost epithelium of hair follicles in synchrony with the anagen phase of hair cycling. Transgenic mice overexpressing sPLA(2)-X (PLA2G10-Tg) displayed alopecia, which was accompanied by hair follicle distortion with reduced expression of genes related to hair development, during a postnatal hair cycle. Additionally, the epidermis and sebaceous glands of PLA2G10-Tg skin were hyperplasic. Proteolytic activation of sPLA(2)-X in PLA2G10-Tg skin was accompanied by preferential hydrolysis of phosphatidylethanolamine species with polyunsaturated fatty acids as well as elevated production of some if not all eicosanoids. Importantly, the skin of Pla2g10-deficient mice had abnormal hair follicles with noticeable reduction in a subset of hair genes, a hypoplasic outer root sheath, a reduced number of melanin granules, and unexpected up-regulation of prostanoid synthesis. Collectively, our study highlights the spatiotemporal expression of sPLA(2)-X in hair follicles, the presence of skin-specific machinery leading to sPLA(2)-X activation, a functional link of sPLA(2)-X with hair follicle homeostasis, and compartmentalization of the prostanoid pathway in hair follicles and epidermis.

Trends in the prevalence of invasive fungal infections from an analysis of annual records of autopsy cases of Toho University.

Clinical diagnosis of invasive fungal infections (IFIs) is sometimes difficult, and obtaining an accurate assessment of trends concerning the prevalence of IFIs is a challenge. The aim of this study was to determine trends in the prevalence of IFIs from an autopsy survey. The retrospective review of autopsy records stored in Toho University was performed on all documented cases with fungal infection from 1955 to 2006. A total of 411 cases of IFIs were detected among 10 297 autopsies. The prevalence of candidiasis decreased from 3.6% (1981-93) to 2.0% (1994-2006), and that of aspergillosis increased throughout the 52-year period and reached 2.0% (1994-2006). The prevalence of IFIs in the patient group comprising haematological disorders was significantly higher (19.9%) than in other patient groups (2.9%), of which the odds ratio was 18.4 for mucormycosis and 10.0 for aspergillosis. The lung was the most common organ involved irrespective of major fungal species, and most cases with candidiasis showed multiple-organ infection. Results confirmed the increasing prevalence of aspergillosis and high risk of IFIs in the patient group with haematological disorders. IFIs were also detected in an immunocompromised state caused not only by primary disease but also by treatment with anti-tumour drugs and corticosteroids.

Evidence of intravenous immunoglobulin as a critical supportive therapy against Clostridium difficile toxin-mediated lethality in mice.

OBJECTIVES: Clostridium difficile produces toxins and is an aetiological organism of pseudomembranous colitis. Immunoglobulin is one of the treatment strategies against fulminant C. difficile infections, but the clinical evidence is still limited. We examined the efficacy of intravenous immunoglobulin (IVIg) in C. difficile toxin (CDT)-mediated lethality and cellular injury in mice. METHODS: Mice were intraperitoneally injected with 0.2 mL of filter-sterilized C. difficile culture supernatant (CDT preparation). The IVIg preparation was intravenously administered at several timepoints. We also examined alteration of intestinal permeability and an apoptosis marker in the gut. In in vitro experiments, HEp-2 cells were incubated with a CDT preparation in the presence or absence of the IVIg preparation, after which cell viability and lactate dehydrogenase release were examined. RESULTS: All control mice died by day 2 after injection of the CDT preparation. The maximum effects of IVIg (100% survival) were observed when the mice were treated with IVIg at the same time as injection of the CDT preparation. The IVIg effects were closely associated with improvement of intestinal vascular permeability and mucosal damage in the gut. In addition, reduction of an apoptosis marker (histone-associated DNA fragments) was demonstrated in the mice treated with IVIg. Interestingly, a smaller increase in histone-associated DNA fragments was observed in FasL-deficient mice treated with the CDT preparation compared with wild-type. CONCLUSIONS: These data demonstrated that IVIg may be protective against CDT-mediated lethality, when administered at the appropriate time. The present data also suggest an increase in intestinal permeability, probably through exaggeration of Fas/FasL-mediated apoptosis, as a key mechanism of C. difficile-mediated diseases.

Histopathological predictors of regional lymph node metastasis at the invasive front in early colorectal cancer.

AIMS: In early colorectal cancer (ECC), prediction of lymph node (LN) metastasis is vital for the decision of additional surgical treatment after endoscopic mucosal/submucosal resection. The aim of this study was to determine the relationship between LN metastasis and comprehensive histopathological findings including the cancer microenvironment in ECC. METHODS AND RESULTS: Using 111 ECC cases, including 36 cases with LN metastasis, histopathological observations and immunohistochemistry for lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), von Willebrand factor, matrix metalloproteinase-7 (MMP-7), CXC chemokine ligand-12 (CXCL12) and angiopoietin-like-4 (ANGPTL4) were conducted. Relationships between LN metastasis and growth pattern, status of muscularis mucosae, depth of cancer invasion, overall histopathological type, histopathological type at the invasive front, tumour budding, neutrophil infiltration in cancer cells (NIC), fibrotic cancer-stroma type, Crohn's-like lymphoid reaction, microscopic abscess formation and lymphatic invasion were determined. In addition, the expression of MMP-7, CXCL12 and ANGPTL4 in cancer cells at the invasive front were also considered in the context of LN metastasis. By multivariate analysis, lymphatic invasion, NIC and MMP-7 expression at the invasive front were independent predictors of LN metastasis. CONCLUSIONS: LN metastasis is regulated not only by the characteristics of cancer cells but also by microenvironmental factors of lymphatics and neutrophils, especially at the invasive front.

Significance of the anatomical properties of a myocardial bridge in coronary heart disease.

A myocardial bridge (MB), partially covering the coronary artery, is a congenital anatomical variant usually present in the left anterior descending coronary artery (LAD). MB causes coronary heart disease (CHD) by 2 distinct mechanisms influenced by the anatomical properties of the MB, such as its length, thickness, and location. One is direct MB compression of the LAD at cardiac systole, resulting in delayed arterial relaxation at diastole, reduced blood flow reserve, and decreased blood perfusion. The other is enhancement of coronary atherosclerosis causing stenosis of the LAD proximal to the MB, occurring because of endothelial injury arising from the abnormal hemodynamics provoked by retrograde blood flow up toward the left coronary ostium at cardiac systole. The magnitude of the effect of the 2 distinct mechanisms of the MB on LAD blood flow is prescribed by a common root of the MB-muscle mass volume generated by those properties. Furthermore, the anatomical properties of the MB are closely associated with the choice of treatment and therapeutic outcome in CHD patients having an MB. Thus, the anatomical properties of an MB should be considered in the diagnosis and management of CHD patients with this anomaly.

Anatomical characteristics of myocardial bridge in patients with myocardial infarction by multi-detector computed tomography.

BACKGROUND: Recent development of multi-detector computed tomography (MDCT) has made the detection of myocardial bridge (MB) easier on the left anterior descending coronary artery (LAD). The LAD segment proximal to the MB is well known to be susceptible to atherosclerosis. Anatomical characteristics of MB on LAD in patients with myocardial infarction (MI) were examined by MDCT. METHODS AND RESULTS: Subjects were 43 MI patients who had MB in the LAD and comprised 2 groups: 14 with culprit lesions in the LAD proximal to MB (culprit group) and 29 without culprit lesions in the LAD (non-culprit group). MB length, MB thickness, and the distance from the orifice of left main trunk (LMT) to MB entrance were compared. Age and coronary risk factors showed no significant difference between the 2 groups. MB length (P=0.011), MB thickness (P=0.035), and index of the length multiplied by thickness of MB (P=0.031) were significantly greater in the culprit group. The distance from the orifice of the LMT to MB entrance was significantly shorter in the culprit group (P=0.006). CONCLUSIONS: Anatomical properties of MB, such as length and thickness of MB as well as MB location, are associated with the formation of culprit lesions of LAD proximal to MB in MI.

The mechanisms underlying fibroblast apoptosis regulated by growth factors during wound healing.

While investigating the mechanisms underlying cell death during wound healing processes, we uncovered the pro-apoptotic effects of basic fibroblast growth factor (bFGF) on granulation tissue fibroblasts following pretreatment with transforming growth factor (TGF)-beta1 in vitro. bFGF induced caspase-3 activation and apoptosis in TGF-beta1-pretreated granulation tissue-derived fibroblasts (GF-1) following bFGF treatment for 48 and 96 h. In contrast, fibroblasts that had been treated in the same manner and that originated from the uninjured dermis did not display apoptosis, indicating that the mechanisms underlying apoptosis events in fibroblasts that originate from normal dermal and wound tissues differ. In this process, we also found that bFGF inhibited Akt phosphorylation at serine 473 and induced a rapid loss of phosphorylation of focal adhesion kinase (FAK) at tyrosine 397 in pretreated GF-1 cells, an event that coincided with the dissociation of phosphorylated FAK from the focal adhesions. Therefore, inhibition of survival signals relayed via the disrupted focal adhesion structures and inactivated Akt following bFGF treatment may lead to apoptosis in GF-1 cells pretreated with TGF-beta1. Pretreatment of GF-1 with TGF-beta1 followed by the addition of bFGF resulted in significantly greater inhibition of phosphorylation of Akt and FAK compared to treatment with TGF-beta1 or bFGF alone. The combinatorial treatment also led to proteolysis of FAK and inhibition of FAK and Akt protein expression in GF-1 cells. These findings demonstrated a significant role for the two cytokines in apoptosis of granulation tissue fibroblasts during wound healing. In vivo studies also confirmed a marked decline in phosphorylation and protein expression of Akt and FAK in bFGF-injected skin wounds. These results led to the hypothesis that temporal activation of TGF-beta1 and bFGF at the injury site promotes apoptosis in granulation tissue fibroblasts, an event that is critical for the termination of proliferative granulation tissue formation.

Adenomyoma of the small intestine in an adult: report of a case.

We report a case of adenomyoma in the small intestine, which is an extremely rare entity. An 81-year-old woman presented to our hospital with a history of three episodes of vomiting accompanied by abdominal pain. Upper gastrointestinal examination via a long tube found intestinal obstruction caused by a tumor of the small intestine. Laparotomy revealed a hard mass, 160 cm distal to the Treitz ligament. Pathological examinations of the resected tumor confirmed a diagnosis of adenomyoma originating in the small intestine. To our knowledge, this is only the second report of an adenomyoma of small intestine causing intestinal obstruction in an adult.

Anatomic properties of myocardial bridge predisposing to myocardial infarction.

BACKGROUND: A myocardial bridge (MB) that partially covers the course of the left anterior descending coronary artery (LAD) sometimes causes myocardial ischemia, primarily because of hemodynamic deterioration, but without atherosclerosis. However, the mechanism of occurrence of myocardial infarction (MI) as a result of an MB in patients with spontaneously developing atherosclerosis is unclear. METHODS AND RESULTS: One hundred consecutive autopsied MI hearts either with MBs [MI(+)MB(+) group; n=46] or without MBs (n=54) were obtained, as were 200 normal hearts, 100 with MBs [MI(-)MB(+) group] and 100 without MBs. By microscopy on LADs that were consecutively cross-sectioned at 5-mm intervals, the extent and distribution of LAD atherosclerosis were investigated histomorphometrically in conjunction with the anatomic properties of the MB, such as its thickness, length, and location and the MB muscle index (MB thickness multiplied by MB length), according to MI and MB status. In the MI(+)MB(+) group, the MB showed a significantly greater thickness and greater MB muscle index (P<0.05) than in the MI(-)MB(+) group. The intima-media ratio (intimal area/medial area) within 1.0 cm of the left coronary ostium was also greater (P<0.05) in the MI(+)MB(+) group than in the other groups. In addition, in the MI(+)MB(+) group, the location of the segment that exhibited the greatest intima-media ratio in the LAD proximal to the MB correlated significantly (P<0.001) with the location of the MB entrance, and furthermore, atherosclerosis progression in the LAD proximal to the MB was largest at 2.0 cm from the MB entrance. CONCLUSIONS: In the proximal LAD with an MB, MB muscle index is associated with a shift of coronary disease more proximally, an effect that may increase the risk of MI.

Microsomal prostaglandin E synthase-1 in both cancer cells and hosts contributes to tumour growth, invasion and metastasis.

mPGES-1 (microsomal prostaglandin E synthase-1) is a stimulus-inducible enzyme that functions downstream of COX (cyclo-oxygenase)-2 in the PGE2 (prostaglandin E2)-biosynthesis pathway. Although COX-2-derived PGE2 is known to play a role in the development of various tumours, the involvement of mPGES-1 in carcinogenesis has not yet been fully understood. In the present study, we used LLC (Lewis lung carcinoma) cells with mPGES-1 knockdown or overexpression, as well as mPGES-1-deficient mice to examine the roles of cancer cell- and host-associated mPGES-1 in the processes of tumorigenesis in vitro and in vivo. We found that siRNA (small interfering RNA) silencing of mPGES-1 in LLC cells decreased PGE2 synthesis markedly, accompanied by reduced cell proliferation, attenuated Matrigel invasiveness and increased extracellular matrix adhesion. Conversely, mPGES-1-overexpressing LLC cells showed increased proliferating and invasive capacities. When implanted subcutaneously into wild-type mice, mPGES-1-silenced cells formed smaller xenograft tumours than did control cells. Furthermore, LLC tumours grafted subcutaneously into mPGES-1-knockout mice grew more slowly than did those grafted into littermate wild-type mice, with concomitant decreases in the density of microvascular networks, the expression of pro-angiogenic vascular endothelial growth factor, and the activity of matrix metalloproteinase-2. Lung metastasis of intravenously injected LLC cells was also significantly less obvious in mPGES-1-null mice than in wild-type mice. Thus our present approaches provide unequivocal evidence for critical roles of the mPGES-1-dependent PGE2 biosynthetic pathway in both cancer cells and host microenvironments in tumour growth and metastasis.

Solitary hepatic lymphangioma: report of a case.

A 52-year-old woman presented with upper abdominal pain. Abdominal ultrasonography showed a 4-cm well-defined mass containing solid and cystic components in segment IV of the liver, and contrast-enhanced T1-weighted magnetic resonance imaging revealed heterogeneous enhancement within the tumor, indicating a solid or fibrous component. There were no cystic lesions in any other organs. A partial hepatectomy was performed, based on a preoperative diagnosis of sclerosing hemangioma and biliary cystadenoma or cystadenocarcinoma. Pathologically, the tumor appeared to be a multilocular and cystic lesion lined by attenuated endothelial- like cells with no atypia. Immunohistochemistry demonstrated the endothelial-like cells to be positive for the lymphatic-specific markers D2-40, LYVE-1, and Prox-1, which proved helpful for confirming the diagnosis as solitary hepatic lymphangioma. This case is presented with details of the pathologic and radiologic findings, because solitary hepatic lymphangioma is an extremely rare tumor and no previous reports have provided details of the immunohistochemical characteristics.

Airway-centered Interstitial Fibrosis Involving Smooth Muscle Hyperplasia with Severe Pulmonary Hypertension.

In the 2013 updated classification of the American Thoracic Society/European Respiratory Society, airway-centered interstitial fibrosis (ACIF) is included as a bronchiolocentric pattern of interstitial pneumonia (IP) among idiopathic IPs. We encountered a case of severe pulmonary hypertension (PH) with chronic IP. The patient initially presented with shortness of breath and often lost consciousness due to PH, and seven years after his first visit, he ultimately died. An autopsy revealed ACIF and usual IP. In particular, the ACIF comprised non-atypical smooth muscle hyperplasia, and pulmonary hypertensive vascular degeneration was detected. This case may represent a new pathological feature of ACIF.

Improvement of radiation-induced healing delay by etanercept treatment in rat arteries.

Surgical treatment often causes difficulty in the irradiated field because of delayed wound healing, which is mainly due to vascular dysfunction. To overcome this difficulty, we attempted to accelerate the recovery from clamp injury in irradiated superficial epigastric arteries of rats as a model. Etanercept, a soluble receptor of tumor necrosis factor-alpha, was administered four times to rats with irradiated arteries before and after clamp injury. Loss of endothelial cells and necrosis of the media in the irradiated arteries continued for more than 1 week after the injury; however, in the rats treated with etanercept, the endothelial cells recovered in the intima, and alpha-smooth muscle actin-positive smooth muscle cells recovered in the injured and irradiated arteries. After clamp injury of common carotid arteries that had previously been irradiated, the blood flow in these arteries was visualized by magnetic resonance (MR) angiography. The time-of-flight signal was weakened in the injured and irradiated arteries. This time-of-flight signal was recovered by the etanercept treatment. These findings suggest that etanercept improves the radiation-impaired healing of arteries in rats.

Basic fibroblast growth factor induces down-regulation of alpha-smooth muscle actin and reduction of myofibroblast areas in open skin wounds.

To examine the effects of basic fibroblast growth factor (bFGF) on the inhibition of alpha-smooth muscle actin (alpha-SMA) expression in dermal fibroblasts, we have established two dermal myofibroblastic cell lines positive for alpha-SMA (rat myofibroblasts [RMF] and rat myofibroblast-like [RMFL] cells) and one fibroblastic cell line negative for alpha-SMA (rat fibroblasts cells) as a model of fibroblast differentiation. In contrast to the increased expression of alpha-SMA in RMF and RMFL cells, irrespective of transforming growth factor-beta1 treatment, bFGF induced a decrease in alpha-SMA expression in the myofibroblastic cells and the reduced expression patterns of alpha-SMA differed between cells, as demonstrated by Western blot and reverse transcription polymerase chain reaction analyses. Along with the inhibition of alpha-SMA expression by bFGF, the RMF and RMFL cells also showed different activated expression of extracellular signal-regulated kinase 1/2, suggesting the involvement of extracellular signal-regulated kinase 1/2 activation in the down-regulation of alpha-SMA expression in myofibroblasts. Furthermore, an in vivo study demonstrated that bFGF administration markedly decreases the area that is positive for alpha-SMA expression in the treated wounds after day 18. In contrast, bFGF administration significantly increased the number of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) staining and alpha-SMA-positive cells at days 10 and 14, and reduced the double-positive cells rapidly after day 18. Collectively, the current investigation identified bFGF as a potent stimulator for the reduction of the myofibroblastic area in vivo, presumably because of its effects on the down-regulation of alpha-SMA expression as well as rapid induction of apoptosis in myofibroblasts.