Long-term vardenafil therapy improves hemodynamics in patients with pulmonary hypertension.

The phosphodiesterase-5 (PDE-5) inhibitor, sildenafil, has been reported to produce sustained pulmonary vasodilatation in patients with pulmonary hypertension (PH). Recently, vardenafil, a more potent and selective PDE-5 inhibitor than sildenafil, has been approved for the treatment of erectile dysfunction. However, the long-term effects of oral vardenafil in patients with PH are unknown. We studied five consecutive patients with PH; one with primary pulmonary hypertension, two with chronic pulmonary thromboembolism, one with Eisenmenger syndrome (ventricular septal defect) and one with secondary pulmonary hypertension after a ventricular septal defect closure operation. In an acute hemodynamic trial, vardenafil (5 mg) significantly decreased both the pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) with an increase in cardiac output. In a chronic hemodynamic trial, the maintenance dose of vardenafil (10 to 15 mg) for 3 months significantly decreased the PVR, but not the SVR, with a 20.7% reduction of the PVR/ SVR ratio. Plasma brain natriuretic peptide (BNP) levels were also significantly decreased after 3 months. This pilot study demonstrates that long-term oral vardenafil therapy may be a safe and effective treatment for patients with PH.     

Beta-catenin mutations are frequent in calcifying odontogenic cysts, but rare in ameloblastomas

We have reported previously that alterations to beta-catenin occur frequently in adamantinomatous craniopharyngioma. Based on its histological resemblance to some odontogenic tumors, we suspected the presence of common genetic alterations among these tumors. To address this issue, 11 cases of calcifying odontogenic cyst (COC) and 20 cases of ameloblastoma were investigated for the presence of beta-catenin mutations and beta-catenin expression. Ten COCs were successfully analyzed by direct sequencing, and nine of them were found to harbor somatic beta-catenin mutations. Immunohistochemically, all of the COCs showed nuclear and cytoplasmic expression of beta-catenin with a heterogeneous pattern. No beta-catenin mutations were found in ameloblastomas, except for one case of the follicular type. All follicular ameloblastomas exhibited moderate nuclear and cytoplasmic accumulation of beta-catenin, in contrast to the predominantly membranous expression seen in the plexiform type. beta-Catenin mutation is considered to be a characteristic genetic feature of COC, and may play a critical role in its histogenesis. Although ameloblastoma closely resembles COC histologically, the two have genetically distinctive features.     

Frequent co-localization of Cox-2 and laminin-5 gamma2 chain at the invasive front of early-stage lung adenocarcinomas

Laminin-5 is an extracellular matrix protein that plays a key role in cell migration and tumor invasion. Cox-2 is an induced isoform of cyclooxygenases that plays an important role in carcinogenesis, suppression of apoptosis, angiogenesis, and metastasis of colon cancer. We report frequent co-expression of cox-2 and laminin-5 at the invasive front of early-stage lung adenocarcinomas. We investigated the expression of cox-2 and laminin-5 immunohistochemically in 102 cases of small-sized lung adenocarcinoma (maximum dimension, 2 cm or less). Cox-2 and laminin-5 were expressed in 97 (95.1%) and 82 (80.4%) cases, respectively. Both were preferentially localized in cancer cells at the cancer-stroma interface, although cox-2 tended to show a diffuse staining pattern in some cases. A comparison of their staining patterns revealed a striking similarity in their distribution in 24 cases, and a partial overlap between their localization in another 20 cases. Moreover, an overall correlation was found between the expression levels of cox-2 and laminin-5 (P = 0.018). To gain insight into the mechanisms that regulate the expression of these proteins, we additionally studied their expression in 58 cases of stage I lung adenocarcinoma, in which p53 status was determined by immunohistochemistry, polymerase chain reaction-single strand conformation polymorphism analysis, and direct sequencing. The results showed that tumors with mutant p53 tended to express more cox-2 than those with wild-type p53 (P = 0.080). Also, tumors that overexpressed p53 had higher levels of cox-2 and laminin-5 than those without p53 overexpression (P = 0.032 and 0.047, respectively). Further immunohistochemical analysis showed that tumors that overexpressed both epidermal growth factor receptor (EGFR) and erbB-2 had higher levels of cox-2 and laminin-5 than those without concomitant overexpression of these proteins (P = 0.014 and P = 0.018, respectively). To see whether EGFR signaling is involved in cox-2 and laminin-5 expression, we further conducted in vitro analyses using six lung adenocarcinoma cell lines (A549, HLC-1, ABC-1, LC-2/ad, VMRC-LCD, and L27). Western blot analyses showed that cox-2 mRNA levels, and to a lesser extent laminin-5 gamma2 mRNA levels, correlated with the expression levels of erbB-2 and the phosphorylated form of MAPK/ERK-1/2 protein. The addition of transforming growth factor-alpha increased both cox-2 and laminin-5 gamma2 mRNA levels in A549, ABC-1, and L27 with different kinetics; the induction of cox-2 occurred earlier than that of laminin-5 gamma2. Finally, the migration of ABC-1 cells was inhibited by MAP kinase kinase inhibitor PD98059 and a selective cox-2 inhibitor NS-398. In contrast, the migration of A549 cells was inhibited by PD98059, but much less effectively by NS-398. These results suggest that co-stimulatory mechanisms may exist that increase the expression of cox-2 and laminin-5 at the invasive front of lung adenocarcinomas and that EGFR signaling could be one of the mechanisms. Further investigations are warranted concerning the role of cox-2 and laminin-5 in cancer cell invasion and the significance of p53 and EGFR signaling in the regulation of cox-2 and laminin-5 expression.     

Conjugation of acetaldehyde with cysteinylglycine,the first metabolite in glutathione breakdown byγ-glutamyltranspeptidase

Glutathione and its metabolites were examined for reactivity to acetaldehyde. When acetaldehyde was incubated with glutathione alone, there was only a slight decrease of acetaldehyde, while an apparently equimolar reaction between acetaldehyde and free sulfhydryl was observed with the addition of -glutamyltranspeptidase. Cysteinylglycine, the first metabolite in the glutathione breakdown by -glutamyltranspeptidase, showed a rapid and equimolar reactivity to acetaldehyde and such was comparable to the reaction seen withl-cysteine ord-penicillamine. In light of the chemical structure, cysteinylglycine probably conjugates with acetaldehyde to form thiazolidinecarboxylic acid derivatives, 2-methyl-thiazolidine-4-carbonyl-glycine, and if so, the alteration of glutathione metabolism by acetaldehyde during ethanol intoxication warrants further attention.     

A noninvasive tissue reflectance oximeter

A newly developed noninvasive tissue reflectance oximeter utilizes 5 light emitting diodes operating at the wavelengths of 0.635, 0.665, 0.795, 0.910, and 0.955 μ, and photodiodes to sample the tissue reflectance spectra. Since the tissue reflectance is affected by changes in both hemoglobin content (Hb _T) and hemoglobin oxygen saturation (OS _T),Hb _T is first determined using the reflectance at 0.795 μ. The hemoglobinOS _T is then estimated using the reflectances at the 5 wavelengths in conjunction with the diffuse reflectance equation which has previously been verified applicable to tissue reflectance oximetry. A quantitative estimation of bothHb _T andOS _T in intestinal mucosa of dogs obtained using this instrument showed thatHb _T values agreed fairly well with those of others and that the standard errors ofOS _T were around 5.0% inOS as compared with theOS values of blood samples for minimized arterial-venousOS differences. The continuous on-line measurement ofHb _T andOS _T should be possible using the reflectance technique and should be valuable for clinical evaluation of the patients.     

High-grade dysplasia associated with fundic gland polyposis in a familial adenomatous polyposis patient, with special reference to APC mutation profiles.

We report a patient with familial adenomatous polyposis who developed high-grade dysplasia against a background of fundic gland polyposis. Two large high-grade dysplasia lesions were found in the gastric body, where numerous fundic gland polyps were present. In both lesions, the dysplastic epithelium covered non-neoplastic oxyntic glands that occasionally exhibit cystic changes. A genetic analysis for APC (adenomatous polyposis coli) revealed a somatic 50-bp deletion involving codons 1502-1517 and 2-bp deletion at codon 1465 in each lesion of high-grade dysplasia. In contrast, six of the 18 fundic gland polyps were found to harbor an identical mutation: 1-bp insertion at codon 1556. Both lesions of high-grade dysplasia and the fundic gland polyps were similarly located in the fundic gland area and were caused by the inactivation of APC; however, their mutation profiles of APC were different. These results imply that fundic gland polyps and high-grade dysplasia of the stomach have distinct preferences for APC genotypes in their development.     

Microsatellite instability in primary and metastatic lung carcinomas

Fifty-seven primary lung carcinomas and 35 metastatic lung carcinomas were analyzed for microsatellite instability at 11 different chromosomal loci. Although no instability was detected in 37 small cell lung carcinomas (SCLC), it was frequently detected in non-small cell lung carcinomas (NSCLC) (16/55, 29%). In NSCLC, the incidence of replication errors (RERs) in metastatic tumors (12/22, 55%) was significantly higher than that in primary tumors (4/33, 12%) (P = 0.0021). Among 10 pairs of primary tumors and corresponding metastases, there were 4 cases which manifested the identical RER phenotypes in both primary and metastatic tumors. In two cases, RER phenotypes were detected in metastatic but not in primary tumors. Never was an RER phenotype found only in a primary tumor but not in the metastases. RERs were detected more frequently in stage III or IV tumors (3/8, 38%) than stage I or II tumors (1/25, 4%) (P = 0.0359). Tumor cells with allelic losses on chromosome arm 3p or 18q tended to have RER phenotypes (P = 0.0432 and P = 0.0187, respectively). The data suggest that microsatellite instability is common in NSCLC but not in SCLC, and that genomic instability appears late in tumor progression and plays an important role in the acquisition of more malignant phenotypes in NSCLC.     

The role of saliva of Anopheles stephensi in inflammatory response: identification of a high molecular weight neutrophil chemotactic factor

Mosquito bites can elicit dermal hypersensitivity reactions, but little is known about the chemotactic factors for host leukocytes in mosquito saliva. In this study, we determined that saliva from a malarial vector mosquito, Anopheles stephensi, possesses intense neutrophil chemotactic activity. In contrast, the midgut extract had only marginal neutrophil chemotactic activity. Eosinophil chemotactic activity was detected in the midgut but not in the saliva. According to the results of size-exclusion HPLC on a G3000SW column and Western blot analysis, the apparent molecular weight (MW) of the main neutrophil chemotactic factor (NCF) was estimated to be 200 kDa. NCF could bind with IgG from the pooled serum of Solomon islanders, whereas not with that of healthy Japanese. NCF activity was increased upon heating to 56 degrees C for 30 min or protease digestion, whereas it was affected by periodate treatment. Protease-digested NCF and naive NCF bound to lentil lectin-Sepharose, and both were eluted with a competitive sugar, methyl-alpha-D-glucoside. These results indicate that A. stephensi saliva-derived NCF is a high MW glycoprotein, and its protein moiety is important for neutrophil chemotactic activity. This NCF is thought to contribute to the inflammatory reactions through the accumulation of neutrophils at the site of the mosquito bite.     

Dysadherin overexpression in pancreatic ductal adenocarcinoma reflects tumor aggressiveness: relationship to e-cadherin expression.

PURPOSE: The E-cadherin-mediated cell adhesion system is frequently inactivated by multiple mechanisms and is involved in tumor progression in many types of cancer. Recently, we reported the cloning and characterization of dysadherin and showed that it downregulated E-cadherin and promoted metastasis. The aim of this study was to investigate the clinical significance of dysadherin expression and the relationship between dysadherin expression and E-cadherin expression in pancreatic ductal adenocarcinoma. PATIENTS AND METHODS: We examined dysadherin and E-cadherin expression in 125 surgically resected pancreatic ductal adenocarcinoma patients using immunohistochemistry. RESULTS: Dysadherin was expressed at the cell membrane of cancer cells, but not in nontumor duct and acinar cells. Its expression was stronger in infiltrative and poorly differentiated nests compared with well-differentiated nests. Although the correlation between the expression of dysadherin and E-cadherin was not significant, a group of patients showed reduced E-cadherin expression with dysadherin overexpression. Increased dysadherin expression was significantly correlated with distant metastasis (P =.047), high tumor grade (P =.006), positive tumor margins (P =.024), and infiltrative type of growth pattern (P =.014). A survival advantage was observed in patients with 0% to 20% dysadherin-positive cells compared with patients with 51% to 100% dysadherin-positive cells, independent of tumor-node-metastasis classification, and World Health Organization tumor grade (P =.019). A combination of increased dysadherin expression and reduced E-cadherin expression (< 90%) further worsened the prognosis. CONCLUSION: In pancreatic ductal adenocarcinoma, dysadherin expression seems to reflect tumor aggressiveness and to be a positive marker of poor prognosis when considered both alone and in combination with downregulation of E-cadherin.