Mitogen-activated protein kinases phosphorylation in posttraumatic selective vulnerability in rats

Mitogenic stimulation of the Mitogen-activated protein kinase (MAPK) pathway modulates the activity of many transcriptional factors leading to biological responses. Of these, three MAPK cascades are well characterized as extracellular signal-regulated protein kinase (ERK), c-Jun NH(2)-terminal kinase (JNK), and p38 pathways. The aim of this study was to investigate the topographic distribution and the role of activated MAPK pathways after fluid percussion injury (FPI) in rats. In the present results, FPI significantly induced ERK- and JNK-phosphorylation, but not p38-phosphorylation in the cortex and hippocampus at the injury site. The immunoreactivity for phospho-ERK was localized in the superficial neuronal layers, dentate hilar neurons, and the damaged CA3 neurons after 30 mins of FPI. Double immunostaining showed that phospho-ERK was prominent in astrocytes 6 hrs after TBI. The current results suggest that MAPK pathways are involved in signal transduction after FPI.

CT is useful for identifying patients with complicated appendicitis

BACKGROUND AND AIMS

We often come across patients with complicated appendicitis (perforation, abscess formation, or peritonitis) and it is essential to get accurate and detailed information on these patients preoperatively. In this study, we investigated whether or not preoperative computed tomography is useful for identifying these patients.

PATIENTS AND METHODS

Plain and intravenously-contrasted helical computed tomography was obtained preoperatively in 94 (75%) of 125 patients who underwent appendectomy. Twenty-eight (30%) of the 94 patients had complicated appendicitis (Compli(+) group). We compared clinical factors and computed tomography findings of the Compli(+) group with those of 66 other patients (Compli(-) group).

RESULTS

There was no significant difference between the Compli(+) and Compli(-) groups in gender, white blood cell count, the present rate of an enlarged appendix, or appendicolith. Fat stranding and free fluid on computed tomography were significantly associated with complicated appendicitis by both univariate and multilogistic regression analysis. Fourteen (70%) of the 20 patients with fat stranding and free fluid on computed tomography had complicated appendicitis and only 1 (4%) of the 28 Compli(+) patients had neither fat stranding nor free fluid on computed tomography.

CONCLUSION

Our study has indicated that fat stranding and free fluid on computed tomography are significant for complicated appendicitis and helical computed tomography is a powerful tool for identifying patients with complicated appendicitis preoperatively.

Gene expression in the cyanobacterium Anabaena sp. PCC7120 under desiccation

The N2-fixing cyanobacterium Anabaena sp. PCC7120 showed an inherent capacity for desiccation tolerance. A DNA microarray covering almost the entire genome of Anabaena was used to determine the genome-wide gene expression under desiccation. RNA was extracted from cells at intervals starting from early to late desiccation. The pattern of gene expression in DNA fragments was categorized into seven types, which include four types of up-regulated and three types of down-regulated fragments. Validation of the data was carried out by RT-PCR on selected up-regulated DNA fragments and was consistent with the changes in mRNA levels. Our conclusions regarding desiccation tolerance for Anabaena sp. PCC7120 are as follows: (i) Genes for osmoprotectant metabolisms and the K+ transporting system are up-regulated from early to mid-desiccation; (ii) genes induced by osmotic, salt, and low-temperature stress are up-regulated under desiccation; (iii) genes for heat shock proteins are up-regulated after mid-desiccation; (iv) genes for photosynthesis and the nitrogen-transporting system are down-regulated during early desiccation; and (v) genes for RNA polymerase and ribosomal protein are down-regulated between the early and the middle phase of desiccation. Profiles of gene expression are discussed in relation to desiccation acclimation.

The role of craniofacial growth in leptin deficient (ob/ob) mice

OBJECTIVES

To elucidate the role of leptin on maxillo-facial morphological growth using hereditary obesity model ob/ob mice, and to examine the presence of the leptin receptor gene expression in the mouse condylar head cartilage.

DESIGN

Leptin was intraperitoneally administered once a day in 10 C57BL/6J (lean) and 10 C57BL/6J-ob (ob/ob) mice (leptin administration group), and phosphate-buffered saline (PBS) in 10 lean and 10 ob/ob mice (PBS administration group), between the fifth and 11th week after birth. The amount of fat, the body amount without fat, the rate of body fat, and the width of the condylar cervical area were measured during the 11th week, and roentgenographic cephalometric analysis was performed at the fifth, eighth, and 11th week. Furthermore, the condylar head cartilage in C57BL/6J mice was stereoscopically excised to extract total RNA, and RT-PCR method was performed regarding the leptin receptor gene.

RESULTS

The body fat amount in ob/ob mice with leptin production insufficiency was greater than that in lean mice, and significant differences were noted in every measurement item regarding maxillo-facial morphology. Recovery of bone length was noted in ob/ob mice by administering leptin. Furthermore, the expression of the leptin receptor gene in the condylar head cartilage was confirmed.

CONCLUSION

Exogenous leptin administration leads to significant increases in craniofacial dimensions; and leptin receptors are expressed in mandibular condylar cartilage. These results indicate an important role for leptin in craniofacial growth and morphology. We speculate that leptin's direct peripheral effect on bone and cartilage is closely involved in this role.

Video-assisted anatomic mediobasal segmentectomy of lung

Although video-assisted thoracic surgery (VATS) is now widely accepted, pulmonary segmentectomy is rarely performed. We present a case series of patients undergoing this procedure. The first patient had multiple arteriovenous malformations of the right mediobasal segment and a leiomyoma in the bronchus of the mediobasal segment. The second patient had multiple pulmonary metastases from colon cancer, including one in the right mediobasal segment. The third patient had metastases in the right ventrobasal and mediobasal segments from a solitary fibrous tumor that originated in the contralateral diaphragm. In the first two patients, a solitary mediobasal segmentectomy was done. In the third patient, a combined ventrobasal and mediobasal bisegmentectomy was performed. There were no complications, and visualization was excellent. Because VATS provides such excellent exposure, mediobasal segmentectomy of the lung is feasible, even though this operation is not done as an open procedure.

Clinical significance of immune cell infiltration within gallbladder cancer

To investigate the pathophysiological significance of infiltrating antitumour immune cells, we evaluated the quantity of immune cell intratumoral infiltration in 110 surgically resected gallbladder specimens by immunohistochemistry. We examined 45 cases of gallbladder cancer and 65 cases of benign gallbladder diseases for CD4⁺ T cells, CD8⁺ T cells, natural killer cells (NKCs), and dendritic cells (DCs). High levels of CD4⁺ T cell, CD8⁺ T cell, NKC, and DC infiltration were recognised in 51.1% (23 out of 45), 37.8% (17 out of 45), 33.3% (15 out of 45), and 48.9% (22 out of 45) of cancer specimens, respectively. High numbers of infiltrating CD4⁺ and CD8⁺ T cells correlated with decreasing tumour invasion, and high numbers of infiltrating DCs correlated with decreasing lymph-node tumour metastasis. Furthermore, increased infiltration of CD4⁺ and CD8⁺ T cells and DCs exhibited a significant correlation with prolonged survival. NKC infiltration, however, did not correlate with any of the clinicopathological factors examined. Additionally, high levels of infiltration were not identified in specimens from benign diseases, consistent with the cancer-specific activity of CD4⁺ and CD8⁺ T cells and DCs. In this study, we demonstrate that CD4⁺ and CD8⁺ tumour-infiltrating lymphocyte and DCs, but not NKCs, are important factors in the accurate prognosis of survival after surgical removal of gallbladder adenocarcinoma.

Arterioportal shunting as an alternative to microvascular reconstruction after hepatic artery resection

Background

Portal vein and hepatic artery resection and reconstruction may be required in radical surgery for biliary cancer. Microvascular reconstruction requires special equipment and training, and may be difficult to accomplish when the arterial stump is small, when there are multiple vessels or when the stump lies deep within the wound. This study examined the feasibility and safety of arterioportal shunting as an alternative to arterial reconstruction.

Methods

Over 30 months, ten patients with biliary cancer (six bile duct and four gallbladder carcinomas) underwent radical surgery with en bloc resection of the hepatic artery and end-to-side arterioportal reconstruction between the common hepatic or gastroduodenal artery and the portal trunk.

Results

No patient died. Complications included bile leakage in two patients and liver abscess in one. Routine angiography performed 1 month after surgery revealed shunt occlusion in three patients. Once the existence of hepatopetal arterial collaterals had been confirmed in the remaining patients, the shunt was occluded by coil embolization.

Conclusion

Arterioportal shunting appears to be a safe alternative to microvascular reconstruction after hepatic artery resection. However, the safety of the procedure and its potential to increase the cure rate require further assessment in a larger series with a longer follow-up.

Mediastinal bronchial artery aneurysm with hematemesis

Mediastinal bronchial artery aneurysm is a rare condition which can lead to potentially fatal hemorrhage. In most cases it presents respiratory symptoms due to rupture into pleural parenchyma. But when it develops mediodorsally and compresses the esophagus, it may cause dysphagia or hematemesis. Here we report a case of mediastinal bronchial artery aneurysm which presented with hematemesis. Computed tomography and endoscopic ultrasound showed what seemed to be a submucosal tumor on the esophagus. We were able to correctly diagnose the aneurysm using magnetic resonance imaging and probe thoracoscopy, and were able to successfully treat with transluminal artery embolization.

An extrapleural approach to the anterior mediastinum using video-assisted thoracic surgery (VATS)

A lateral extrapleural approach via video-assisted thoracic surgery (VATS) was used in a patient suspected of having a benign tumor of right lobe of the thymus. The patient previously had undergone lung resection for pulmonary tuberculosis, and the ipsilateral thorax had contracted and dense pleural adhesions were likely to exist. Lateral extrapleural approach by VATS was performed successfully and is an alternative to open surgery in highly selected patients with anterior mediastinal lesions.

Overexpression of hypoxia-inducible-factor 1alpha(HIF-1alpha) in oesophageal squamous cell carcinoma correlates with lymph node metastasis and pathologic stage

The purpose of this study is to investigate the clinical and histopathologic significance of hypoxia-inducible-factor 1alpha (HIF-1alpha) expression in oesophageal squamous cell carcinoma. One hundred and thirty surgically resected specimens of OSCC were immunohistochemically assessed for HIF-1alpha expression with monoclonal antibody. High HIF-1alpha immunostaining was detected in 40 specimens. The percentage of high HIF-1alpha expression cases increased with tumour stage according to pTNM system. High HIF-1alpha expression correlated with pTNM stage, depth of tumour invasion, lymph node metastasis, distant metastasis, lymphatic invasion and positive surgical margin. The overall survival rate was worse in patients with high HIF-1alpha pattern than in patients with low-expression pattern. Univariate analyses identified high HIF-1alpha positivity, depth of tumour invasion, lymph node metastasis, distant metastasis, lymphatic invasion, and a positive surgical margin as risk factors. Multivariate analyses indicated that depth of tumour invasion, lymph node metastasis and positive surgical margin, but not HIF-1alpha, were independent prognostic factors. Survival in patients with a high HIF-1alpha expression was significantly worse than in those with low expression in patient treated with adjuvant therapy.

[Off-pump coronary artery bypass grafting using donut and SPY]

Off-pump coronary artery bypass grafting (OPCAB) has been rapidly increased, because of its less invasiveness with low complications. However, graft patency rate highly depends on operators' capability due to technical difficulties. In this article, detail operative procedures are introduced to perform OPCAB in 100% for isolated coronary patients. Selecting better stabilizer may be a key of success. Donut Heart Stabilizer can make a still and stable operative field to anastomose less than 1 mm coronary artery. It is very useful to achieve complete revascularization for all stenosed coronary branches. OPCAB with 9 arterial grafts could be done using Donut. SPY Intra-operative Imaging System is also important to get 100% patency rate of the grafts. Using SPY, we can avoid graft trouble during operation in operation room (OR). SPY image is the best key information for operators to decide revision of the failed grafting. Donut 2 Heart Stabilizer has been improved to make more wide and stable operative field. Donut and SPY is the best combination for OPCAB.

Portal vein resection and reconstruction prior to hepatic dissection during right hepatectomy and caudate lobectomy for hepatobiliary cancer

BACKGROUND

Hepatobiliary cancer invading the hilar bile duct often involves the portal bifurcation. Portal vein resection and reconstruction is usually performed after completion of the hepatectomy. This retrospective study assessed the safety and usefulness of portal vein reconstruction prior to hepatic dissection in right hepatectomy and caudate lobectomy plus biliary reconstruction, one of the common procedures for radical resection.

METHODS

Clinical characteristics and perioperative results were compared in patients who underwent right hepatectomy and caudate lobectomy plus biliary reconstruction with (ten patients) and without (11 patients) portal reconstruction from September 1998 to March 2002.

RESULTS

All ten portal vein reconstructions were completed successfully before hepatic dissection; the portal cross-clamp time ranged from 15 to 41 (median 22) min. Blood loss, blood transfusion during the operation, postoperative liver function, morbidity and length of hospital stay were similar in the two groups. No patient suffered postoperative hepatic failure or death.

CONCLUSION

This study demonstrates that portal vein reconstruction does not increase the morbidity or mortality associated with right hepatectomy and caudate lobectomy with biliary reconstruction. This approach facilitates portal vein reconstruction for no-touch resection of hepatobiliary cancer invading the hilar bile duct.

Caveolin-I overexpression is a favourable prognostic factor for patients with extrahepatic bile duct carcinoma

Extrahepatic bile duct carcinoma (EBDC) is a malignancy well known for its poor prognosis. Some clinicopathological prognostic markers have been proposed, but genetic factors have not been well investigated. We have examined expression patterns of caveolin-1, which has been shown to function as a tumour suppressor in vitro, in EBDC using immunohistochemistry. Normal tissues adjacent to the tumour cells did not show immunoreactivity for caveolin-1. A total of 22 of the 60-carcinoma tissue samples (36.7%) studied were positive for caveolin-1. Caveolin-1 immunostaining negatively correlated with the patient's age and pathological T factor (pT) in a statistically significant manner. Multivariate analysis using Cox's proportional hazards model identified caveolin-1 expression as an independent positive prognostic factor. Thus, our study suggests that caveolin-1 expression may be a useful prognostic marker for EBDC.

Initial medical management of patients severely irradiated in the Tokai-mura criticality accident

A nuclear criticality accident occurred in Japan on September 30, 1999, which resulted in severe exposure of three victims to mixed flux of neutrons and gamma-rays. Estimated average doses for the three victims were 5.4 Gy of neutrons and 8.5 Gy of gamma-rays for Patient A, 2.9 Gy of neutrons and 4.5 Gy of gamma-rays for Patient B, and 0.81 Gy of neutrons and 1.3 Gy of gamma-rays for Patient C. They then suffered the consequences of the effects of ionizing radiation resulting in acute radiation syndrome. In Patients A and B, bone marrow failure was so severe that they received haematopoietic stem cell transplantation. The graft initially took successfully in both patients, although in Patient B it was later taken over by his own haematopoietic cells. They also suffered from severe skin lesions, later exhibited gastrointestinal bleeding and eventually died of multiple organ failure 82 and 210 days after the accident, respectively. The survival of these patients beyond the period of agranulocytosis means that bone marrow failure per se caused by exposure to ionizing radiation may now be overcome. Patient C also developed bone marrow failure and was treated with granulocyte colony-stimulating factor as well as supportive care. He recovered without major complications and is now under periodical follow-up. Remarkably, during the prodromal phase, all the patients exhibited hypoxaemia, two of whom also showed interstitial oedema of the lungs. In Patient C these manifestations improved within a week. The circumstances of the accident and the initial medical treatment of the victims are described.

Gelsolin suppresses tumorigenicity through inhibiting PKC activation in a human lung cancer cell line, PC10

Gelsolin expression is frequently downregulated in lung cancer and several types of different human cancers. To examine the effects of gelsolin restoration on tumorigenicity, we here stably expressed various levels of gelsolin via gene transfer in lung cancer cells (squamous cell carcinoma line, PC10). We observed the alterations in tumorigenicity in vivo when implanted in nude mice, and the changes in growth properties in vitro. As compared to parental cells and control clones, gelsolin transfectants highly reduced tumorigenicity and repressed cell proliferation. Moreover, we investigated bradykinin-induced responses in gelsolin-overexpressing clones, because agonist-stimulated activation of the phospholipases C (PLC)/protein kinase C (PKC) signal transduction pathway is critical for cell growth and tumorigenicity. Bradykinin promotes phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis by PLC and translocation of various PKC isoforms from the cytosolic fraction to the particulate fraction. Bradykinin treatment did not increase inositoltriphosphate (IP3) production and induce the membrane fractions of PKC alpha and PKC gamma in gelsolin tranfectants, while it induced PIP2 hydrolysis and increased the fractions in parental and control clones. These results suggest that gelsolin suppressed the activation of PKCs involved in phospholipid signalling pathways, inhibiting cell proliferation and tumorigenicity.

Impact of caveolin-1 expression on prognosis of pancreatic ductal adenocarcinoma

Caveolin-1 is a major component of caveolae and plays a regulatory role in several signalling pathways. Caveolin-1 was recently identified as a metastasis-related gene in prostate cancer. The clinical effects of caveolin-1 expression in pancreatic carcinoma, however, remain unknown. In this study, we have investigated the relationship between caveolin-1 expression and the clinicopathologic variables and clinical outcome in 79 patients with pancreatic adenocarcinoma undergoing surgical resection. Caveolin-1 expression was determined by immunohistochemistry, using a polyclonal anti-caveolin-1 antibody. Patients were divided into two groups based on the extent of caveolin-1 expression: a negative expression group (immunoreactivity in less than 50% of cells) and a positive expression group. Positive caveolin-1 immunostaining was detected in 32 cases (40.5% of total), while non-neoplastic ductal epithelium showed little or no staining. Positive caveolin-1 expression was correlated with tumour diameter (P=0.0079), histopathologic grade (P=0.0272) and poor prognosis (P=0.0008). Upon multivariate analysis with Cox's proportional hazards model, positive caveolin-1 expression was shown to be an independent negative predictor for survival (P=0.0358). These results suggest that caveolin-1 overexpression is associated with tumour progression, thereby indicating a poor prognosis for certain patients undergoing surgical resection for pancreatic carcinoma.

Seven-day triple therapy with omeprazole, amoxycillin and clarithromycin for Helicobacter pylori infection in haemodialysis patients

BACKGROUND

Triple therapy is accepted as the treatment of choice for Helicobacter pylori eradication, but there is no consensus on how long the therapy should be maintained in haemodialysis (HD(+)) patients. Our aims in this study were to evaluate the safety and efficacy of the 7-day triple therapy in HD(+) patients.

METHOD

Forty-seven HD(+) and 55 HD(-) patients with dyspepsia underwent endoscopy. The prevalence of H. pylori was detected by Giemsa stain, followed by the urea breath test (UBT). H. pylori(+) patients were scheduled to undergo 7-day triple therapy and the success of eradication was investigated by UBT.

RESULTS

Forty-five (44%) patients were positive for H. pylori. Forty of them underwent triple therapy and 39 (98%) patients completed the treatment. Eradication was successful in 32 (82%) and unsuccessful in 7 (18%) patients. There was no significant difference between these groups in age, gender, endoscopic findings or HD, and only previous treatment was significant for eradication failure by univariate and multivariate logistic regression analysis. Side effects were observed in 2 (15%) of 13 HD(+) and 3 (11%) of 27 HD(-) patients, and one HD(-) patient had to stop medication because of severe nausea and vomiting. The eradication rate was 93% (28/30) in patients without previous treatment. The triple therapy was unsuccessful in 7 patients, and 4 of them again underwent 7-day triple therapy, but all resulted in failure.

CONCLUSIONS

Seven-day triple therapy is safe and effective for primary treatment of H. pylori infection in both HD(+) and HD(-) patients, but a new treatment is necessary for patients with previous treatment.

Are both PIVKA-II and alpha-fetoprotein necessary in follow-up management after hepatic resection for hepatocellular carcinoma?

BACKGROUND/AIMS

The aim of this study was to clarify the need for measuring of PIVKA-II (protein induced by vitamin K absence or antagonist-II) and alpha-fetoprotein as the prognostic indicator for patients after hepatic resection for hepatocellular carcinoma, and as the monitoring modality for early detection of recurrence after hepatic resection.

METHODOLOGY

One hundred and thirty-one patients who underwent planned liver resections for hepatocellular carcinoma were studied.

RESULTS

The survival rates in patients positive for preoperative tumor markers were significantly lower than in those in the negative patients. The first modality leading to the diagnosis of recurrence was measurement of alpha-fetoprotein and/or PIVKA-II in 25 cases (55.6%). Almost all patients (96.6%) with positive preoperative alpha-fetoprotein and recurrence had elevated alpha-fetoprotein again when recurrence was found.

CONCLUSIONS

Preoperative PIVKA-II and/or alpha-fetoprotein levels can predict postoperative prognosis. Measurement of these markers is useful in monitoring recurrence. For following up patients with alpha-fetoprotein-producing tumors, alpha-fetoprotein monitoring only is sufficient to detect recurrence.

N-acetylgalactosaminyl transferase-3 is a potential new marker for non-small cell lung cancers

N-acetylgalactosaminyl transferase-3 (GalNAc-T3) is an enzyme involved in the initial glycosylation of mucin-type O-linked proteins. In the present study, we used immunohistochemistry to examine GalNAc-T3 expression in 215 surgically resected non-small cell lung cancers. We analysed the biological and clinical importance of GalNAc-T3 expression, especially with regard to its potential as a prognostic factor. We found that normal bronchial epithelial cells, bronchial gland cells, and alveolar pneumocytes showed cytoplasmic immunostaining for GalNAc-T3. Low expression of GalNAc-T3, observed in 93 of 215 tumours (43.4%), was found more frequently in tumours from smokers than those from nonsmokers (P=0.001), in squamous cell carcinomas than nonsquamous cell carcinomas (P<0.0001), and in moderately and poorly differentiated tumours than well differentiated tumours (P=0.0002). Multivariate logistic regression analysis showed that an association of low GalNAc-T3 expression with squamous cell carcinomas was the only one significant relationship of GalNAc-T3 expression with various factors (P<0.0001). Moreover, tumours losing GalNAc-T3 expression had a significantly higher Ki-67 labelling index than tumours retaining GalNAc-T3 expression (P=0.0003). Patients with low GalNAc-T3 expression survived a significantly shorter time than patients with high GalNAc-T3 expression in 103 pStage I non-small cell lung cancers (5-year survival rates, 58% and 78%, respectively; P=0.02 by log-rank test) as well as in 61 pStage I nonsquamous cell carcinomas (5-year survival rates, 63% and 85%, respectively; P=0.03). Low GalNAc-T3 expression was an unfavourable prognostic factor in pStage I non-small cell lung cancers (hazards ratio, 2.04; P=0.03), and in pStage I nonsquamous cell carcinomas (hazards ratio, 2.70; P=0.03). These results suggest that GalNAc-T3 is a new marker of non-small cell lung cancers with specificity for histology and prognosis.

Genetic variation of symbiotic fungi cultivated by the macrotermitine termite Odontotermes formosanus (Isoptera: Termitidae) in the Ryukyu Archipelago

Fungus-growing termites have a mutualistic relationship with their cultivated fungi. To improve understanding of genetic aspects of this relationship, we examined molecular markers in the fungus-growing termite Odontotermes formosanus and its fungi Termitomyces spp. from the Ryukyu Archipelago. Based on the polymorphic band patterns obtained from arbitrarily primed polymerase chain reaction methods, we constructed cladograms for related colonies of the termites and fungi. The resulting trees indicated that the termites display little genetic variation among the colonies, while the symbiotic fungi consist of two major genetic types. In addition, molecular phylogenetic trees of the symbiotic fungi based on internal transcribed spacer and 18S rDNA suggested that these two types of fungi are different species. We also demonstrated that the fungi comprising the fruiting bodies and fungus combs are identical, and that fungus combs are probably a monoculture within a single termite colony. Our results indicate that horizontal transmission of symbiotic fungi among termite colonies occurred during the evolutionary history of this symbiosis.

Female gender as a risk factor for hypokalemia and QT prolongation after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) often causes hypokalemia and QT prolongation. The sex disparities among 73 patients with SAH and 96 control subjects were examined. On the first day of SAH, the mean serum potassium level was significantly lower and the mean corrected QT interval was significantly longer in the female SAH group compared with either the female control or male SAH group. These findings suggest female susceptibility to hypokalemia and QT prolongation after SAH.

Hypoxia enhances the expression of autocrine motility factor and the motility of human pancreatic cancer cells

The incidence of distant metastases is higher in the tumours with low oxygen pressure than in those with high oxygen pressure. It is well known that hypoxia induces the transcription of various genes involved in angiogenesis and anaerobic metabolism necessary for the growth of tumour cells in vivo, suggesting that hypoxia may also induce the transcription of metastasis-associated genes. We sought to identify the metastasis-associated genes differentially expressed in tumour cells under hypoxic conditions with the use of a DNA microarray system. We found that hypoxia enhanced the expression of autocrine motility factor mRNA in various cancer cells and also enhanced the random motility of pancreatic cancer cells. Autocrine motility factor inhibitors abrogated the increase of motility under hypoxic conditions. In order to explore the roles of hypoxia-inducible factor-1alpha, we established hypoxia-inducible factor-1alpha-transfectants and dominant negative hypoxia-inducible factor-1alpha-transfectants. Transfection with hypoxia-inducible factor-1alpha and dominant-negative hypoxia-inducible factor-1alpha enhanced and suppressed the expression of autocrine motility factor/phosphohexase isomerase/neuroleukin mRNA and the random motility, respectively. These results suggest that hypoxia may promote the metastatic potential of cancer cells through the enhanced autocrine motility factor/phosphohexase isomerase/neuroleukin mRNA expression and that the disruption of the hypoxia-inducible factor-1 pathway may be an effective treatment for metastasis.

Frequent expression of new cancer/testis gene D40/AF15q14 in lung cancers of smokers

We found a significant correlation between lung cancer in smokers and the expression of a human gene, D40, predominantly expressed in testis and cancers. In an attempt to clone a novel human gene, we screened a cDNA library derived from a human B cell line and obtained a cDNA clone that we refer to as D40. A search for public databases for sequence homologies showed that the D40 gene is identical to AF15q14. D40 mRNA is predominantly expressed in normal testis tissue. However, this gene is also expressed in various human tumour cell lines and primary tumours derived from various organs and tissues, such as lung cancer. We examined the relationship between D40 expression and clinico-pathological characteristics of tumours in primary lung cancer. D40 expression did not significantly correlate with either histological type or pathological tumour stage. However, D40 expression was observed more frequently in poorly differentiated tumours than in well or moderately differentiated ones. Furthermore, the incidence of D40 expression was significantly higher in tumours from patients who smoke than in those from non-smokers. D40/AF15q14 is the first gene in the cancer/testis family for which expression is related to the smoking habits of cancer patients.

The influence of node-fibril morphology on healing of high-porosity expanded polytetrafluoroethylene grafts

PURPOSE

To manufacture high-porosity expanded polytetrafluoroethylene (ePTFE) vascular grafts with the same internodal distance but different node-fibril morphology, and to evaluate their biologic behaviors in a canine carotid artery implantation model.

MATERIALS AND METHODS

Several types of high-porosity ePTFE vascular grafts with the same inside diameter (4 mm) and wall thickness (650 microm) were manufactured under different heating, stretching conditions. The luminal surface and cross section of the grafts were photographed by scanning electron microscopy and the node-fibril structure was examined. Two typical types of high-porosity ePTFE vascular grafts were then selected and proceeded to an animal study. The test grafts were explanted after an interval of 12 weeks and subjected to histomorphometric analyses.

RESULTS

The following two types of high-porosity ePTFE vascular grafts were selected; one had a through-pore structure extending from the outer to the inner surface and the other had a random-node architecture with tortuous path channels extending from the outer to the inner surface. The histomorphometric analyses of thrombus-free surface, thickness of pseudointima, cellular ingrowth, capillary ingrowth, and cellular proliferation revealed no significant differences between the grafts.

CONCLUSION

In high-porosity ePTFE vascular grafts, graft healing enhanced by transmural tissue ingrowth may be not largely dependent on node-fibril morphology. This knowledge will be helpful to design a new type of high-porosity ePTFE vascular grafts available for clinical use.