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.

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.

Catechin, green tea component, causes caspase-independent necrosis-like cell death in chronic myelogenous leukemia.

Management strategies of chronic phase chronic myelogenous leukemia (CML) have been revolutionized due to the discovery of a selective tyrosine kinase inhibitor, imatinib (Gleevec, STI571), which is substantially improving median survival. However, emergence of imatinib-resistance has put up a serious problem that requires novel treatment methods. Catechins, polyphenolic compounds in green tea, are gathering much attention due to their potential antitumor effects. So far (-)-epigallocatechin-3-gallate (EGCG), the most abundant component of catechin, has been shown to cause typical apoptosis in several tumor cell lines in most cases through activation of caspases. In this study, we showed that EGCG predominantly caused necrosis-like cell death via a caspase-independent mechanism in CML cells, K562 and C2F8, whereas imatinib induced the typical apoptotic cell death. Moreover, this caspase-independent cell death partially mediated the release of apoptosis-inducing factor, AIF, and serine protease, HtrA2/Omi, from the mitochondria to cytosol. In addition, EGCG enhanced the imatinib-induced cell death (P < 0.01) resulting in additive cell death in K562 cells and EGCG alone, effectively reduced the viability of imatinib-resistant K562 cells (P < 0.01). Catechin is a possible candidate for an antitumor agent that causes cell death in CML cells via a caspase-independent mechanism.

Promoted activation of matrix metalloproteinase (MMP)-2 in keloid fibroblasts and increased expression of MMP-2 in collagen bundle regions: implications for mechanisms of keloid progression.

AIMS: Keloid is characterized by excessive deposition of collagen, resulting from aberrant extracellular matrix (ECM) production and degradation. The aim was to investigate the role of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in pathological wound healing in keloids. METHODS AND RESULTS: Semiquantitative analysis of 60 keloid tissue samples and 25 mature scar tissue samples demonstrated significantly increased expression of MMP-2, TIMP-2 and TIMP-3 in keloids compared with mature scars. Within keloid regions, MMP-2 expression was significantly higher in collagen bundle regions than in non-collagen bundle regions. Double immunofluorescence revealed that keloid fibroblasts between collagen bundles exhibited MMP-2, TIMP-2 and membrane-type 1 MMP (MT1-MMP) co-expression, whereas only MMP-2 expression was evident on the edge of collagen bundles. Western blot analysis and gelatin zymography of 13 keloid-derived fibroblasts (KFbs) and six normal skin dermal-derived fibroblasts (NFbs) demonstrated that unstimulated KFbs exhibited significantly increased MMP-2 activity and expression compared with NFbs under the same conditions. CONCLUSIONS: These results together indicate that MMP-2 activity can be promoted in keloid fibroblasts between collagen bundles in cooperation with TIMP-2 and MT1-MMP. This could contribute to remodelling of collagen bundle regions and invasion of fibroblasts into peripheral normal regions through promoted degradation of ECM.

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.

Significance of lymphatic invasion and cancer invasion-related proteins on lymph node metastasis in gastric cancer.

BACKGROUND AND AIMS: Cancer invasion and metastasis are critical events for patient prognosis; however, the most important step in the whole process of lymph node (LN) metastasis in gastric cancer remains obscure. In this study, the significance of cancer cell behaviors, such as cell detachment, stromal invasion and lymphatic invasion on regional LN metastasis in gastric cancer was investigated by comprehensive immunohistochemistry. METHODS: A total of 210 cases with gastric cancer were selected. These consisted of 105 cases with regional LN metastasis (LN[+] group) and 105 cases without LN metastasis (LN[-] group). Both groups exhibited the same depth of invasion. Cancer tissues were subjected to immunohistochemistry with antibodies against claudin-3, claudin-4, beta-catenin, matrix metalloproteinase (MMP)-1, and MMP-2, as well as endothelial markers of lymphatic vessel endothelial hyaluronan receptor-1 and von Willebrand factor for the objective discrimination between lymphatics and blood vessels. The expression of each protein as well as the histopathological parameters were compared between LN(+) and LN(-) groups. RESULTS: Along with lymphatic invasion by cancer cells and gross tumor size, MMP-1 expression in cancer cells at the invasive front of the primary tumor was a significant, independent predictor of LN metastasis. The expression of claudins and beta-catenin was associated with the histopathological type of cancer, but not with LN status. CONCLUSION: Among the cancer invasion-related proteins examined, MMP-1 plays a vital role in LN metastasis of gastric cancer. Tumor size, lymphatic invasion and MMP-1 expression level at the invasive front were the predictive factors of LN metastasis of gastric cancer.

Basic fibroblast growth factor inhibits ventricular remodeling in Dahl salt-sensitive hypertensive rats.

OBJECTIVE: Basic fibroblast growth factor (bFGF) inhibits the progression of ventricular remodeling in ischemic and hypertensive heart diseases (HHDs). Recent studies have revealed that bFGF induces the transition from myofibroblasts to fibroblasts with decreased expression of alpha-smooth muscle actin (alpha-SMA). To clarify the mechanisms underlying the reduced ventricular remodeling in hypertensive heart diseases caused by bFGF, we examined the degree of interstitial fibrosis associated with alpha-smooth muscle actin expression and matrix metalloproteinase activity in hypertensive heart diseases. METHODS: Dahl salt-sensitive rats were fed with a high-salt diet from 6 to 18 weeks of age and injected with a single dose of bFGF (100 microg) into the left myocardium at 15 weeks. Others were administered PBS without bFGF. Control age-matched Dahl salt-sensitive rats were fed with a low-salt diet. RESULTS: Cardiac systolic function was well preserved and decompensation of heart failure was prevented at 18 weeks in the rats treated with bFGF at 15 weeks. The bFGF-treated rats had significantly fewer interstitial alpha-SMA-positive myofibroblasts and significantly decreased prolyl 4-hydroxylase expression. Increased matrix metalloproteinase-9 gelatinase activity correlated with the downregulation of transforming growth factor-beta1 by bFGF, suggesting that inhibited extracellular matrix deposition is associated with a decreased number of myofibroblasts induced by bFGF. CONCLUSION: bFGF can inhibit the progression of ventricular remodeling by inhibiting interstitial fibrosis and promoting angiogenesis without decreasing blood pressure in hypertensive heart disease.

TRAF activation of C/EBPbeta (NF-IL6) via p38 MAPK induces HIV-1 gene expression in monocytes/macrophages.

C/EBPbeta plays a pivotal role in activation of human immunodeficiency virus type 1 (HIV-1) in monocytes/macrophages. However, mechanisms for functional regulation of C/EBPbeta remain uncharacterized. Previous studies indicated that NF-kappaB activation by tumor necrosis factor (TNF) receptor family, which activates TNF receptor associated factor (TRAF), induces HIV-1 expression. We found that TRAF signals activate HIV-1 LTR with mutations of NF-kappaB sites in promonocytic cell line U937, suggesting existence of an alternative HIV-1 activating pathway. In this study, we have characterized the signal transduction pathway of TRAF other than that leading to NF-kappaB, using U937 cell line, and its subline, U1, which is chronically infected by HIV-1. We show that signals downstream of TRAF2 and TRAF5 activate p38 MAPK, which directly phosphorylates C/EBPbeta, and that activation of p38 MAPK potently activates C/EBPbeta-mediated induction of HIV-1 gene expression. We also show TRAF2 and TRAF5 are expressed in monocytes/macrophages of spleen samples from HIV-1 infected patients. Identification of TRAF-p38 MAPK-CEBPbeta pathway provides a new target for controlling reactivation of latent HIV-1 in monocytes/macrophages.

Significance of lymphatic invasion on regional lymph node metastasis in early gastric cancer using LYVE-1 immunohistochemical analysis.

It has been reported that lymphatic invasion is a predictor for lymph node metastasis in early gastric cancer (EGC); however, it has been impossible to differentiate between lymphatic invasion and blood vessel invasion using current staining techniques. We studied the significance of lymphatic invasion on regional lymph node metastasis in EGC by using human lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) antibody, specific to lymphatic vessels, and von Willebrand factor (vWF) antibody, specific to the blood vessels, to clearly distinguish these vascular tissues.EGC tissues were obtained from 66 node-positive and 66 node-negative subjects and were matched by age and sex. These tissues were immunostained with antibodies against LYVE-1 and vWF. Multivariate logistic regression analysis demonstrated that lymphatic invasion was a significant independent predictor for regional lymph node metastasis (odds ratio, 4.667; P = .0094), whereas blood vessel invasion was not. Thus, lymphatic invasion identified by LYVE-1 antibody could predict the existence of regional lymph node metastasis in EGC.

Significance of lymphatic invasion and proliferation on regional lymph node metastasis in renal cell carcinoma.

We studied the associations of lymphatic invasion and lymphatic vessel density around tumors with lymph node (LN) status in renal cell carcinoma (RCC) by immunohistochemical analysis using D2-40 antibody as a lymphatic marker. Surgically removed specimens from 76 cases with RCC, including 16 cases with LN metastasis, were used. Lymphatic vessel density around the tumor increased compared with normal kidneys but was not significant by LN status. Tumor size, tumor cell types, patterns of tumor growth, nuclear grade of tumor cells, venous invasion, lymphatic invasion, and primary tumor stage were predictive factors for LN metastasis. Based on multivariate regression analysis, only lymphatic invasion was an independent risk factor for LN metastasis. The immunohistochemical detection of lymphatics was useful for identifying the lymphatic invasion of RCC, and the presence of lymphatic invasion around RCC was an independent predictive factor for LN metastasis.

Significance of anatomical properties of myocardial bridge on atherosclerosis evolution in the left anterior descending coronary artery.

Myocardial bridge (MB) is frequently detected in the left anterior descending coronary artery (LAD), and LAD intima under MB is significantly spared from atherosclerotic evolution. Significance of anatomical features of MB on the extent of atherosclerosis of LAD was histomorphometrically investigated. Full-length 200 LADs with MB and 100 control LADs without MB were cross-sectioned at 5 mm intervals, and atherosclerosis ratio and intimal lesion types were evaluated. In cases with MB located within 5 cm from the left coronary ostium, atherosclerosis ratio in the proximal part of LAD was significantly lower than in control group, but, in cases with MB locating more than 5 cm from the ostium, atherosclerosis ratio in this part was similar to that in control cases. MB thickness was significantly correlated with its length, and the longer the MB the more proximally it tended to be located in LAD. Atherosclerosis ratio under MB was lower in cases with thick or long MBs than in cases with thinner or shorter MBs. In addition, intimal lesion in segments proximal to MB tended to be eccentric. Our results suggest that these anatomical properties of MB are the critical modulators for atherosclerosis evolution in the entire course of LAD.

Ligand-independent signaling by overexpressed CD30 drives NF-kappaB activation in Hodgkin-Reed-Sternberg cells.

Overexpression of CD30 and constitutive NF-kappaB activation characterizes tumor cells of Hodgkin's disease (HD), Hodgkin and Reed-Sternberg (H-RS) cells. We report that in H-RS cells overexpression of CD30 leads to self-aggregation, recruitment of TRAF2 and TRAF5, and NF-kappaB activation, independent of CD30 ligand. CD30 and TRAF proteins co-localized in H-RS cell lines and in lymph nodes of HD. An adenovirus-vector carrying a decoy CD30 lacking the cytoplasmic region or a dominant negative IkappaBalpha mutant blocks NF-kappaB activation, down regulates IL-13 expression and induces apoptosis. Thus, in H-RS cells, ligand-independent activation of CD30 signaling drives NF-kappaB activation and this leads to constitutive cytokine expression, which provides a molecular basis for HD. Inhibition of NF-kappaB activation by adenovirus vector-mediated gene transfer may provide a novel strategy of cell- and target molecule-specific therapy for patients with HD.

Limited association of Chlamydia pneumoniae detection with coronary atherosclerosis.

The association of Chlamydia pneumoniae (C. pneumoniae) detection with atherosclerosis has been controversial because of recent conflicting results. In order to assess how and to what extent C. pneumoniae detection contributes to atherosclerosis, the association between immunohistochemical detection of C. pneumoniae antigen, intimal lesions, and the intimal thickening ratio was examined in 1674 left anterior descending coronary arterial segments from 100 autopsied Japanese patients being free from coronary heart disease. These specimens contained full spectrum of atherosclerotic lesions as defined by the American Heart Association classification. The intimal thickening ratio increased in C. pneumoniae-positive sections comparing to that in C. pneumoniae-negative sections only in the group with normal intima and diffuse intimal thickening, but there was no such association in the other advanced intimal lesion groups. Furthermore, in 50 C. pneumoniae-positive cases out of 100 investigated, the frequency and extent of immunoreactivity did not associate with progression of intimal lesions or the intimal thickening ratio, and the mean score of C. pneumoniae detection did not correlate with the mean intimal thickening ratio in individual cases. These results suggest only a limited association between C. pneumoniae detection and coronary atherosclerosis development and that C. pneumoniae does not influence promotion of atherosclerotic lesions. The role of C. pneumoniae on atherogenesis may be limited only at the beginning stage of atherosclerosis development.

Fibromuscular dysplasia of coronary arteries resulting in myocardial infarction associated with hypertrophic cardiomyopathy in Noonan's syndrome.

The first autopsy case of fibromuscular dysplasia in the coronary arteries associated with hypertrophic cardiomyopathy in Noonan's syndrome is reported. A 16-month-old female infant with no significant family history was diagnosed with Noonan's syndrome and subsequently died of cardiac and respiratory failure. Autopsy revealed cardiac hypertrophy, atrial septal defect, and scar lesions in the left ventricle and ventricular septum. Histologically, the myocardium exhibited myocardial fiber disarray, which was indicative of hypertrophic cardiomyopathy. The main trunks of the coronary arteries showed protuberant intimal thickening with interruption of the internal elastic lamina. Intramyocardial coronary arteries also exhibited various degrees of irregular intimal proliferation and diffuse fibrous thickening of the adventitia. These arterial lesions were consistent with fibromuscular dysplasia. Small arteries around the scar showed remarkable stenoses, which probably led to myocardial ischemia. The fibromuscular dysplasia in this case was considered to arise as a cardiovascular disorder in conjunction with Noonan's syndrome.

Immunohistochemical detection of human small lymphatic vessels under normal and pathological conditions using the LYVE-1 antibody.

The spread of tumor cells via lymphatic vessels to the lymph nodes is an important indicator of malignancy. However, previous markers used to identify lymphatic endothelium gave ambiguous results in immunohistochemical analyses with paraffin-embedded tissues. In this study, we attempted to prepare a polyclonal antibody against human lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) for detecting lymphatic vessels using immunohistochemistry. The antibody was raised against a region near the transmembrane anchor of LYVE-1 in New Zealand white rabbits. Immunostainings with anti-LYVE-1 and von Willebrand factor antibodies were performed in various normal and pathological tissues. LYVE-1 expression was confined to the endothelial surface of lymphatic vessels but was not found in the endothelium of blood vessels, which were positive for von Willebrand factor. Our LYVE-1 polyclonal antibody was useful for the identification of small lymphatic vessels in normal human tissues. In addition, the immunostaining enabled us to distinguish lymphatic invasion by malignant tumor cells from blood vessel invasion using paraffin-embedded sections. In conclusion, our polyclonal antibody against the transmembrane anchor of the peptide can be used to detect human lymphatic vessels under various conditions.

Expression of P-glycoprotein in rat hepatocarcinogenesis by diethylnitrosamine and the modulation by anticancer drugs.

P-glycoprotein (P-GP) is known to be a multidrug resistant 1 gene product and to exhibit resistance to a broad range of drugs including anticancer drugs such as epirubicin. Its overexpression is reported in human hepatocellular carcinoma and in adenomatous hyperplasia of the liver as well. In order to clarify the evolution of P-GP expression during hepatocarcinogenesis and its modulation by anticancer drugs, we performed an immunohistochemical study in male Wistar rat livers exposed to diethylnitrosamine (DEN) for 12 weeks. Some rats were pretreated with cisplatin or epirubicin 1 week prior to the exposure, and some rats were treated with them at the 10th week after the exposure. While there was no P-GP expression in the liver of the control, cisplatin, and epirubicin (DEN-free) rats, expression was confirmed in the hepatocytes of DEN-treated rats. The immunostaining of hyperplastic nodules was significantly more intense than in well-differentiated hepatocellular carcinomas, and no staining was observed in poorly-differentiated carcinomas. Markedly intense staining was observed in the early hyperplastic nodules of cisplatin-pretreated rats, as well as in epirubicin-pretreated rats. Plasma alpha-fetoprotein levels were markedly elevated in DEN-treated rats, while tumor necrosis factor-alpha levels were not. In conclusion, the results suggest that P-GP confers a protective effect against anticancer drugs and provides a great advantage to the initiated cells. Furthermore, in addition to epirubicin, cisplatin also promotes the induction of P-GP in the initiated cell.

Histiocytic sarcoma with fatal duodenal ulcers.

Histiocytic sarcoma is an uncommon neoplasm of mature histiocytes with very poor outcome. We report an autopsy case of a true histiocytic sarcoma with characteristic symptoms of so-called "malignant histiocytosis of the intestine". The liver and spleen were enlarged, with remarkable tumor cell infiltration in the hepatic sinusoids and splenic sinuses. Tumor cells aggregated to form sporadic nodular lesions in the liver, which often showed coagulative necrosis. Infarcted lesions also occurred at the splenic subcapsular area. In addition, tumor cell infiltration was noted in the sinuses of bone marrow and lymph node. Tumor cells often demonstrated moderate pleomorphism with multinucleated giant cells. They were positive for CD68 and negative for T- and B-cell lineage markers, megakaryocytic markers, and CD30. Various examinations were done to rule out infection-associated hemophagocytic syndrome, and the absence of infectious diseases was revealed. Thus, the diagnosis of histiocytic sarcoma was made. Apart from these lesions, multiple ulcerations, some with fatal perforation, were found in the esophagus and duodenum. They showed only non-specific inflammatory changes without tumor cell involvement. The ulcers probably derived from ischemic condition through an embolic process caused by tumor cell infiltration elsewhere in the blood vessels at the periphery of the ulcers.

Changes in renal vessels following the long-term administration of an angiotensin II receptor blocker in Zucker fatty rats.

INTRODUCTION: The nephro-protective effects of angiotensin II receptor blockers (ARBs) are widely known; however, there are few reports of long-term effects focusing on the renal vessels. We studied afferent arteriolar changes induced by the long-term administration of an ARB. MATERIALS AND METHODS: Thirty-two 6-week-old male Zucker fatty rats (ZFRs) were divided into following four groups (n = 8 in each): ZFR Group and ZFR+High Group fed a standard or high-salt diet, respectively; ZFR+ARB Group and ZFR+High+ARB Group fed a standard or high-salt diet with ARB (Olmesartan, 5 mg/kg/day), respectively. Blood pressure, proteinuria, morphological examinations and glomerular haemodynamics in vivo were studied. RESULTS: Marked proliferative changes in the afferent arteriolar smooth muscle cells (SMCs) were frequently observed in the two groups given ARBs; in the ZFR+ARB group (77.3±10.3%) compared with the two groups without ARB (1.7%, p < 0.005; 1.2%, p < 0.0005) and 37.4±15.6% in the ZFR+High+ARB group. Proteinuria markedly decreased in the groups treated with ARBs, but the glomerular erythrocyte velocities showed no differences. CONCLUSIONS: Our findings indicate that long-term ARB administration induced unusual proliferative changes in SMCs of afferent arterioles of ZFRs. These changes could narrow arteriolar lumens and reduce intraglomerular pressure, but they could cause also irreversible damage to the arterioles.

Histopathological predictor for regional lymph node metastasis in gastric cancer.

Regional lymph node metastasis in gastric cancer is a definitive indicator of the patient's prognosis. The goal of this study was to identify the predictors for lymph node metastasis among all the possible histopathological parameters, especially by conducting an objective discrimination of the lymphatic and blood vessels. A total of 210 resected primary gastric cancers with or without lymph node metastasis were evaluated based on the conventional histopathological parameters together with immunohistochemistry using antisera-recognizing lymphatic endothelial hyaluronan receptor-1 (LYVE-1), von Willebrand factor, and lymphangiogenesis promoter vascular endothelial growth factor-C (VEGF-C) antibodies. A multivariate regression analyses of the results indicated that only lymphatic invasion was a significant independent predictor of lymph node metastasis at any stage of cancer invasion. VEGF-C expression was partially related to lymph node metastasis in early gastric cancer. The identification of lymphatic invasion by LYVE-1 antibody is therefore useful to predict regional lymph node metastasis in gastric cancer.

Histopathologic determinants of regional lymph node metastasis in early colorectal cancer.

BACKGROUND: Early colorectal cancer (ECC) is curable by endoscopic local resection; however, 10% of patients with ECC exhibit lymph node (LN) metastasis. In the current study, accurate predictors for LN metastasis in patients with ECC were examined by using immunohistochemistry with the lymphatic endothelial hyaluronan receptor 1 (LYVE-1) antibody to discriminate between lymphatics and blood vessels. METHODS: Colorectal tissue specimens obtained from 71 patients with ECC, including 28 patients with regional LN metastasis, were immunostained with antibodies against LYVE-1, beta-catenin, claudin-3, claudin-4, and cytokeratin. The significance of the histopathologic variables for LN metastasis in ECC was investigated on the basis of specific histopathologic parameters. RESULTS: Lymphatic invasion confirmed by LYVE-1 immunohistochemistry was observed mainly in the submucosal area around the primary tumor and rarely was observed in the tumor. Expression patterns of beta-catenin, claudin-3, and claudin-4 in cancer cells at the invasive front were irrelevant to LN status. Tumor size, depth of invasion, histologic tumor type, budding formation, and lymphatic invasion were statistically significant to LN status in univariate analysis; however, only 2 factors--lymphatic invasion and budding formation at the invasive front-were independent predictors of LN metastasis in ECC. CONCLUSIONS: LYVE-1 immunohistochemistry appeared to be a useful method for detecting lymphatics invaded by cancer cells, and detailed examination of the submucosa around the tumor may be important for predicting LN metastasis. When lymphatic invasion and budding formation are observed histopathologically in patients with ECC, additional therapy, such as adjuvant chemotherapy or a curative resection of the regional LN, may be required.