P224 Valvuloplasty treatment and three-dimensional analysis for isolated cleft of the anterior mitral valve leaflet: a case report

Introduction: Isolated cleft of the anterior mitral valve leaflet is a very rare congenital disease and a cause of mitral regurgitation

not associated with atrioventricular septal defect. In this case, we report our experience in valvuloplasty treatment for mitral regurgitation with this rare aetiology.

Case description

23-year-old Russian women. Although cardiac murmur was pointed out in her childhood and she was diagnosed as mitral regurgitation, she refused treatment. After getting married with a Japanese man and moving to Japan, her symptoms had worsened and she visited our hospital for treatment. Preoperative transthoracic echocardiography (TTE) had indicated the regurgitation from the central part of the mitral valve. Preoperative transoesophageal echocardiography (TOE) had pointed out the isolated cleft of the anterior mitral valve.

Surgical mitral valvuloplasty was scheduled, and the TOE after anaesthetic induction showed the isolated cleft of the anterior mitral valve the same as in the preoperative period and pointed out the posterior leaflet billowing. The operative finding was also similar to TOE: the largely bisected central anterior mitral valve and billowing, P2 billowing, shortening of P1 and P3, P2-3 cleft. There were no chords at the anterior cleft. The valvuloplasty was performed including five-time pump runs in total: 1) Continuous suture for the anterior cleft and ring annuloplasty were performed, and the regurgitation was seemed to be almost controlled at the water-leak test and the ink test; 2) Artificial chordae and leaflet plications were added to residual regurgitation from the posterior region; 3)The residual regurgitation was controlled to Mild but it became a lateral jet toward the ring; 4)Mild remnant flow was pointed out: the regurgitation seemed to be from the posterior cleft, where immediately below the ring suture; 5) Pericardium patch was added and the remnant flow was almost eliminated. The pump was weaned and the operation was finished without any problems.

Discussion

The cause of difficulty in this valvuloplasty was thought to be caused by the difficulty in evaluating the mitral valve morphology. It was evident that the anterior leaflet of the mitral valve was largely bisected. However, it was difficult to evaluate the coaptation line and area due to the absence of chordal cords in the anterior cleft and the billowing or shortening of the posterior leaflet. Although preoperative three-dimensional analysis helped evaluating the isolated cleft and the regurgitation was almost controlled in the evaluation in the operation field, nevertheless, a residual regurgitation occurred and indicated in the TOE after re-beating.

Conclusion

It is important and necessary to use fine evaluation of coaptation is needed in valvuloplasty for isolated cleft of the anterior mitral valve leaflet; not only apply three-dimensional analysis but also apply two-dimensional echocardiogram.

Abstract P224 Figure.

Characterization of theL-Lysine Biosynthetic Pathway in the Obligate MethylotrophMethylophilus methylotrophus

The L-lysine biosynthetic pathway of the gram-negative obligate methylotroph Methylophilus methylotrophus AS1 was examined through characterization of the enzymes aspartokinase (AK), aspartsemialdehyde dehydrogenase, dihydrodipicolinate synthase (DDPS), dihydrodipicolinate reductase, and diaminopimelate decarboxylase. The AK was inhibited by L-threonine and by a combination of L-threonine and L-lysine, but not by L-lysine alone, and the activity of DDPS was moderately reduced by L-lysine. In an L-lysine producing mutant (G49), isolated as an S-(2-aminoethyl)-L-cysteine (lysine analog) resistant strain, both AK and DDPS were partially resistant to feedback inhibition. The ask and dapA genes encoding AK and DDPS respectively were isolated from the parental strain, AS1, and its G49 derivative. Comparison of the sequences revealed a point mutation in each of these genes in G49. The mutation in the ask gene altered aspartic acid in a key region involved in the allosteric regulation common to AKs, while a novel mutation in the dapA gene altered tyrosine-106, which was assumed to be involved in the binding of L-lysine to DDPS.

Characterization of a Unique MutantlysEGene, Originating fromCorynebacterium glutamicum, Encoding a Product That InducesL-Lysine Production inMethylophilus methylotrophus

lysE24 is an allele of lysE encoding an L-lysine exporter of Corynebacterium glutamicum. The mutant gene is able to induce L-lysine production in Methylophilus methylotrophus. Although lysE24 has a mutation in the middle of lysE that results in chain termination, the entire lysE locus, including the region downstream of the short open reading frame, is necessary for L-lysine production. We propose that separate polypeptides are synthesized from the lysE24 locus due to reinitiation of translation utilizing an existing start codon beyond the site of the frameshift, and present evidence that translational coupling is required to form the functional lysE24 product. In addition, expression of lysE24 induces L-lysine production in another methylotroph, Methylobacillus glycogenes. These data suggest that the lysE24 product is a split protein and that this curious feature might be a structure necessary for its functioning in certain obligate gram-negative methylotrophs.

Suppression methods of radon emanation from phosphorus fertiliser and diatomaceous earth

The present paper shows methods to suppress radon emanation from artificial porous materials such as phosphorous fertiliser or diatomaceous earth with a small amount of radium. The basic concept of suppression is making the radon emanation mechanism 'null', which comes from the fact that recoil is the main mechanism of radon emanation at room temperature. Nullifying may be done through removal of water in the pore volume by heating and through removal of pores by melting or filling with sulphur. These radon emanation suppression methods were tried for phosphorous fertiliser and diatomaceous earth with a small amount of radium. The melting method was the most effective of all. Sustainability of these methods was also studied. The melting method was the most sustainable. The heating method was also sustainable for diatomaceous earth in spite of a long-term immersion in water.

Enhancement of l-lysine production in methylotroph Methylophilus methylotrophus by introducing a mutant LysE exporter

The obligate methylotroph Methylophilus methylotrophus AS1 expressing a mutant form of dapA (dapA24) encoding a dihydrodipicolinate synthase desensitized from feedback inhibition by L-lysine could secrete L-lysine into the medium, but also maintained a high concentration of intracellular L-lysine. To improve the yield from excretion, we attempted to introduce an L-lysine/L-arginine exporter (LysE) from Corynebacterium glutamicum 2256 into M. methylotrophus. We were unable to stably transform M. methylotrophus with a plasmid expressing the wild type lysE gene, but happened to obtain a transformant carrying a spontaneously mutated lysE gene (designated lysE24) which could induce L-lysine production even in the wild type strain. The transformant also possessed increased tolerance to S-(2-aminoethyl)-L-cysteine (an L-lysine analog). lysE24 has a single-base insertion mutation in the middle of the lysE gene, and its product is presumably quite different in structure from wild-type LysE. When lysE24 was introduced into an L-lysine producer of M. methylotrophus carrying dapA24, the level of intracellular L-lysine fell. During fermentation, M. methylotrophus carrying both lysE24 and dapA24 produced 10-fold more L-lysine (11.3 gl(-1) in jar-fermentation) than the parent producer carrying only dapA24 or lysE24. These results show the importance of the factor (lysE24) involved in the excretion of L-lysine on its overproduction in M. methylotrophus.

l-Lysine biosynthetic pathway of Methylophilus methylotrophus and construction of an l-lysine producer

Previously, we showed that the enzymes aspartokinase (AK) and dihydrodipicolinate synthase (DDPS), which are involved in L-lysine biosynthesis in the Gram-negative obligate methylotroph Methylophilus methylotrophus AS1, were inhibited by allosteric effectors, including L-lysine. To elucidate further the regulation of L-lysine biosynthesis in M. methylotrophus, we cloned the genes encoding three other enzymes involved in this pathway, L-aspartate-beta-semialdehyde dehydrogenase, dihydrodipicolinate reductase (DDPR) and diaminopimelate decarboxylase, and examined their properties. DDPR was markedly inhibited by L-lysine. Based on this and our previous results, we constructed an L-lysine-producing strain of M. methylotrophus by introducing well-characterized genes encoding desensitized forms of AK and DDPS, as well as dapB (encoding DDPR) from Escherichia coli, using a broad host range plasmid. L-Lysine production was significantly increased by employing an S-(2-aminoethyl)-L-cysteine (L-lysine analog)-resistant mutant as the host. This derivative accumulated L-lysine at a concentration of 1 g l(-1) of medium using methanol as a carbon source.

Does incineration turn infectious waste aseptic?

Incineration of infectious waste is considered to be biologically safe. We performed basic experiments to confirm that bacillus spores are killed by incineration in a muffle furnace. Biological samples containing 10(6) spores of Bacillus stearothermophilus were placed in stainless steel Petri dishes and then into hot furnaces. The furnace temperature and duration of incineration were 300 degrees C for 15 min, 300 degrees C for 30 min, 500 degrees C for 15 min, 500 degrees C for 30 min and 1100 degrees C for 3 min. We confirmed that all spores of B. stearothermophilus were killed at each of these settings. The effect of incineration seems to be equivalent to that of sterilization, based on the satisfactory sterilization assurance level of 10(-6).

Neoadjuvant chemoradiotherapy followed by esophagectomy for initially resectable squamous cell carcinoma of the esophagus with multiple lymph node metastasis

Neoadjuvant chemoradiotherapy (CRT) was expected to improve surgical curability and prognosis for advanced esophageal cancer. However, the clinical efficacy of neoadjuvant CRT followed by esophagectomy with three-field lymphadenectomy (3FL) for initially resectable esophageal squamous cell carcinoma (SCC) remains unclear. Since 1998, we have defined the status of metastases to five or more nodes, or nodal metastases present in all three fields as multiple lymph node metastasis, which was previously shown to be associated with poor prognosis. Between 1998 and 2002, 83 patients with initially resectable esophageal SCC were prospectively allocated into two groups, according to the clinical status of nodal metastasis. Nineteen patients clinically accompanied by multiple lymph node metastasis initially underwent neoadjuvant CRT followed by curative esophagectomy with 3FL (CRT group). The other 64 patients clinically without multiple lymph node metastasis immediately received curative esophagectomy with 3FL (control group). Although the overall morbidity rate was significantly higher in the CRT group, no in-hospital death occurred in either group. Patients without pathologic multiple lymph node metastasis in the CRT group showed a significantly better disease-free survival rate than either patients pathologically with multiple lymph node metastasis in the control group or those in the CRT group. However, the differences in the overall survival rate among the groups were not significant. Thus, the significant survival benefit by neoadjuvant CRT in addition to esophagectomy with 3FL was not confirmed, although it may have been advantageous, without increase in mortality, to at least some patients who responded well to neoadjuvant CRT. Therefore, neoadjuvant CRT can be an initial treatment of choice for resectable esophageal SCC clinically with multiple lymph node metastasis. The prediction of response to CRT and the development of alternative treatment for hematogenous recurrence could achieve a further survival benefit of this trimodality treatment.

Prospective randomized study of open versus laparoscopy-assisted distal gastrectomy with extraperigastric lymph node dissection for early gastric cancer

BACKGROUND

Laparoscopy-assisted surgery with extraperigastric lymph node dissection for gastric cancers has been described, but the clinical benefits of these surgeries still are unclear. Short-term clinical outcomes were compared between laparoscopy-assisted distal gastrectomy (LADG) and conventional open distal gastrectomy (ODG) for early gastric cancer in a prospective randomized fashion.

METHODS

For this study, 28 patients with early gastric cancers in the lower half of the stomach were randomly assigned to either LADG (n = 4) or ODG (n = 14). Postoperative pain, levels of acute inflammatory responses, and pathologic evaluation of the operative specimens were compared.

RESULTS

The LADG group required a significantly shorter period of postoperative epidural anesthesia, showed significantly lower levels of serum interleukin-6 and C-reactive protein, and had no major postsurgery complications. Pathologic examinations showed that surgery was equally radical in the two groups.

CONCLUSION

The findings show that LADG with extraperigastric lymph node dissection is a safe and less invasive alternative to the open procedure.

Prospective randomized study of open versus laparoscopy-assisted distal gastrectomy with extraperigastric lymph node dissection for early gastric cancer

BACKGROUND

Laparoscopy-assisted surgery with extraperigastric lymph node dissection for gastric cancers has been described, but the clinical benefits of these surgeries still are unclear. Short-term clinical outcomes were compared between laparoscopy-assisted distal gastrectomy (LADG) and conventional open distal gastrectomy (ODG) for early gastric cancer in a prospective randomized fashion.

METHODS

For this study, 28 patients with early gastric cancers in the lower half of the stomach were randomly assigned to either LADG (n = 4) or ODG (n = 14). Postoperative pain, levels of acute inflammatory responses, and pathologic evaluation of the operative specimens were compared.

RESULTS

The LADG group required a significantly shorter period of postoperative epidural anesthesia, showed significantly lower levels of serum interleukin-6 and C-reactive protein, and had no major postsurgery complications. Pathologic examinations showed that surgery was equally radical in the two groups.

CONCLUSION

The findings show that LADG with extraperigastric lymph node dissection is a safe and less invasive alternative to the open procedure.

Prognostic value of preoperative serum immunosuppressive acidic protein in patients with esophageal squamous cell carcinoma

Immunosuppressive acidic protein (IAP) is a potent biological marker of immunological surveillance in patients with malignant tumors. The aim of this study was to analyze the clinicopathologic significance of IAP in patients with esophageal carcinoma. Preoperative serum IAP concentration was measured by enzyme-linked immunosorbent assay in 115 patients with primary esophageal squamous cell carcinomas. The associations between clinicopathologic factors, C-reactive protein (CRP) values and IAP concentration were determined. Prognostic values were determined by multivariate analysis using Cox's proportional hazards model. The IAP concentration is significantly higher in patients with stage II-IV cancers than in those with stage I cancer. Significant differences in IAP concentration were observed depending upon tumor size, tumor depth, lymph node status and CRP values. A high IAP concentration, more than 500 micro g/mL, was an independent prognostic factor. Thus, a high IAP concentration is associated with tumor progression and poor survival in patients with esophageal squamous cell carcinoma.

Prognostic significance of the number of metastatic lymph nodes in early gastric cancer

BACKGROUND

The prognostic value of the number of metastatic lymph nodes in early gastric cancer has not been evaluated much, although the significance of metastatic lymph nodes is defined by the location of positive nodes, according to the JRSGC for gastric cancer.

METHODS

The postoperative courses of 305 early gastric cancer patients who had undergone D2-extended lymphadenectomy were followed up for a median of 108 months to evaluate the significance of the number of metastatic lymph nodes on recurrence of the disease.

RESULTS

Recurrence of gastric cancer was more frequently observed in submucosal cancer than in mucosal cancer. All patients but one who revealed recurrence had nodal metastasis at the time of surgery. In cases with 1-3 metastatic lymph nodes, no patient had revealed any sign of recurrence; however, in cases with 4 or more metastatic lymph nodes, 6 of 7 patients died of recurrent disease. There were 3 cases of bone metastases, 2 of peritoneal dissemination, and 1 each of both recurrent diseases.

CONCLUSIONS

These data suggest that in n-positive cases, in which there are 4 or more metastatic lymph nodes, there is a high probability of recurrence of early gastric cancer, and especially of hematogenic metastasis.

Preclinical study of adenoviral p53 gene therapy for esophageal cancer

An alteration of the p53 gene function is a major factor in the development of esophageal cancer. Recently, p53 gene therapy has been applied for clinical studies in lung cancer and head and neck cancer. However, no preclinical studies have yet demonstrated an anticancer effect of adenoviral-mediated wild-type p53 gene therapy on esophageal cancer. We herein evaluated the effect of p53 adenoviral gene therapy on human esophageal squamous cell carcinoma to test the ability of clinical application. A normal esophageal epithelial cell line (EN53F) and two human esophageal cancer cell lines (ECGI-10 and T.Tn) with a p53 alteration were used. The transduction efficiency, p53 protein expression, p21 protein expression, the induction of apoptosis, and growth suppression were assessed by using the recombinant adenoviral vector Ad5CMV-p53. The transduction efficiency was 60%-80% at 100 plaque-forming units (PFU)/cell and 80%-100% at 300PFU/cell. A significant growth suppression following an Ad5CMV-p53 infection was observed in both cancer cell lines. A Western blot analysis confirmed the presence of both exogenous p53 protein expression and p21 protein induction. Apoptotic cell death was observed with TUNEL staining. T.Tn xenografts in nude mice transduced with Ad5CMV-p53 demonstrated significant growth suppression. These data suggest that Ad5CMV-p53 may thus be a potentially effective therapeutic agent for locally advanced esophageal cancer.

Presence of serum p53 antibodies is associated with decreased in vitro chemosensitivity in patients with esophageal cancer

Resistance to chemotherapy remains a serious problem inhibiting the successful treatment of advanced esophageal cancer. A number of studies have revealed that p53 genetic alteration and protein overexpression can predict chemosensitivity. Furthermore, p53 protein overexpression in cancer tissues has been found to induce serum p53 antibodies (p53-Abs). This study was conducted to examine whether analysis of serum p53 Abs could predict the chemosensitivity of esophageal cancer. Serum analysis of p53 antibodies was performed by enzyme-linked immunosorbent assay in 19 patients with esophageal squamous cell carcinoma preoperatively, then surgically resected specimens were stained immunohistochemically for p53 protein expression. Tumor tissues were also analyzed for chemosensitivity by the histoculture drug response assay (HDRA) using cis-dichlorodiammineplatinum(II) (CDDP), 5-fluorouracil (5-FU), and adriamycin (ADM). Serum p53-Abs were present in 47% (9/19) of the patients and immunohistochemical analysis revealed overexpression of p53 protein in 42% (8/19) of the tumors. The presence of serum p53 antibodies was significantly correlated with p53 immunoreactivity (P = 0.005). The inhibition index of patients positive for p53-Abs was significantly lower than that of patients negative for p53-Abs (P < 0.001). This tendency was also observed in the inhibition index to 5-FU. The presence of serum p53-Abs was associated with decreased in vitro chemosensitivity to CDDP and 5-FU. Thus, the detection of serum p53-Abs is suggested to be useful for predicting chemosensitivity in patients with esophageal cancer.

Long-term outcomes of immunosuppressed renal transplant recipients with malignancies

This study analyzes ten cases of malignancy in a cohort of 183 renal transplant recipients, examining surgical management, postoperative immunosuppressive therapy, and long-term outcome. One of these ten patients, who had malignant lymphoma of the jejunum, died of the neoplasm, but the other nine patients did not show any signs of tumor recurrence after removal. All of these nine patients, except for one who had transplant renal cell carcinoma (RCC), received the same dose of immunosuppressive agents after surgery for the malignant disease. Seven patients were still alive at the time of this report, six of whom had good transplant renal function. The findings of this study indicate that even if immunosuppressive agents predispose to the development of cancer, it is not necessary to reduce their dose after removal of the tumor.

Copper metabolism after living donor liver transplantation for hepatic failure of Wilson's disease from a gene mutated donor

There is a genetic problem in living donor liver transplantation, involving Wilson's disease, because the majority of donors have a kinship relationship. Recently, it was reported that the serum ceruloplasmin level is insufficient in some persons with one allele mutation. The recipient was a 13-year-old male child, and the donor was a 22-year-old woman, who was his sister by a different father. The gene analysis for Wilson's disease (ATP7B gene) was preoperatively carried out by the amplification refractory mutation system-PCR. Homozygous and heterozygous deletion of 2871 cytosine (C) were detected in the recipient and donor, respectively, in the ATP7B gene. Serum ceruloplasmin level was sufficient in the donor. The right hepatic lobe graft was transplanted to the recipient. Immediately after the liver transplantation, the copper metabolism improved to increase the serum ceruloplasmin levels up to the normal range, and decrease the urinary copper excretion. However, the serum ceruloplasmin levels gradually decreased below the normal base line, although the urine copper levels continued to be low without any clinical symptoms. We should perform gene analyses and confirm the serum ceruloplasmin levels in donors before living donor liver transplantation for Wilson's disease, to screen for their impairment of copper metabolism. After living donor liver transplantation for Wilson's disease, we should carefully follow-up the transition of serum ceruloplasmin levels in the recipient.

Clinical significance of serum vascular endothelial growth factor in esophageal squamous cell carcinoma

BACKGROUND

Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis in malignant tumors. An increased in the serum VEGF concentration (S-VEGF) has been found in patients with various solid tumors and appears to be correlated with tumor burden. The objective of the current study was to determine the correlation between pretreatment S-VEGF and clinicopathologic features in patients with esophageal squamous cell carcinoma.

METHODS

Pretreatment S-VEGF was measured by enzyme-linked immunoadsorbent assay in 24 healthy controls and 96 patients with esophageal squamous cell carcinoma (82 patients with primary tumors and 14 with recurrent tumors). Chemoradiotherapy was performed in 35 patients followed by response evaluation.

RESULTS

S-VEGF was found to be significantly elevated in patients with primary esophageal carcinoma (P = 0.0011). Significant differences were observed when S-VEGF was categorized by tumor size (P = 0.0002), tumor depth (P = 0.0082), lymph node metastasis (P = 0.0002), distant metastasis (P = 0.028), and International Union Against Cancer TNM stage (P < 0.0001). The patients who achieved a partial or complete response to chemoradiotherapy showed significantly less S-VEGF than those patients who were nonresponders (P = 0.018). A high (> 451 pg/mL) S-VEGF level was associated with poor survival (P < 0.001). Multivariate analysis found S-VEGF to be a significant and independent prognostic factor (P < 0.001).

CONCLUSIONS

In the current study, a high S-VEGF was found to be associated with tumor progression, poor treatment response, and poor survival in patients with squamous cell carcinoma of the esophagus.

Clinical significance of serum vascular endothelial growth factor in esophageal squamous cell carcinoma

BACKGROUND

Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis in malignant tumors. An increased in the serum VEGF concentration (S-VEGF) has been found in patients with various solid tumors and appears to be correlated with tumor burden. The objective of the current study was to determine the correlation between pretreatment S-VEGF and clinicopathologic features in patients with esophageal squamous cell carcinoma.

METHODS

Pretreatment S-VEGF was measured by enzyme-linked immunoadsorbent assay in 24 healthy controls and 96 patients with esophageal squamous cell carcinoma (82 patients with primary tumors and 14 with recurrent tumors). Chemoradiotherapy was performed in 35 patients followed by response evaluation.

RESULTS

S-VEGF was found to be significantly elevated in patients with primary esophageal carcinoma (P = 0.0011). Significant differences were observed when S-VEGF was categorized by tumor size (P = 0.0002), tumor depth (P = 0.0082), lymph node metastasis (P = 0.0002), distant metastasis (P = 0.028), and International Union Against Cancer TNM stage (P < 0.0001). The patients who achieved a partial or complete response to chemoradiotherapy showed significantly less S-VEGF than those patients who were nonresponders (P = 0.018). A high (> 451 pg/mL) S-VEGF level was associated with poor survival (P < 0.001). Multivariate analysis found S-VEGF to be a significant and independent prognostic factor (P < 0.001).

CONCLUSIONS

In the current study, a high S-VEGF was found to be associated with tumor progression, poor treatment response, and poor survival in patients with squamous cell carcinoma of the esophagus.

Successful surgical treatment of renal cell carcinoma in a transplanted kidney from a cadaveric donor: report of a case

Posttransplant renal cell carcinoma (RCC) usually arises in the native kidneys of renal transplant recipients rather than in the transplanted kidney. This report describes a case of RCC that developed in the transplanted cadaveric kidney in a 37-year-old male recipient 9 months after transplantation. An en bloc radical transplant nephrectomy was performed, and he has subsequently remained stable on hemodialysis for 3 years without any sign of recurrence.

Clinical significance of serum vascular endothelial growth factor in esophageal squamous cell carcinoma

BACKGROUND

Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis in malignant tumors. An increased in the serum VEGF concentration (S-VEGF) has been found in patients with various solid tumors and appears to be correlated with tumor burden. The objective of the current study was to determine the correlation between pretreatment S-VEGF and clinicopathologic features in patients with esophageal squamous cell carcinoma.

METHODS

Pretreatment S-VEGF was measured by enzyme-linked immunoadsorbent assay in 24 healthy controls and 96 patients with esophageal squamous cell carcinoma (82 patients with primary tumors and 14 with recurrent tumors). Chemoradiotherapy was performed in 35 patients followed by response evaluation.

RESULTS

S-VEGF was found to be significantly elevated in patients with primary esophageal carcinoma (P = 0.0011). Significant differences were observed when S-VEGF was categorized by tumor size (P = 0.0002), tumor depth (P = 0.0082), lymph node metastasis (P = 0.0002), distant metastasis (P = 0.028), and International Union Against Cancer TNM stage (P < 0.0001). The patients who achieved a partial or complete response to chemoradiotherapy showed significantly less S-VEGF than those patients who were nonresponders (P = 0.018). A high (> 451 pg/mL) S-VEGF level was associated with poor survival (P < 0.001). Multivariate analysis found S-VEGF to be a significant and independent prognostic factor (P < 0.001).

CONCLUSIONS

In the current study, a high S-VEGF was found to be associated with tumor progression, poor treatment response, and poor survival in patients with squamous cell carcinoma of the esophagus.

Bmx tyrosine kinase has a redundant function downstream of angiopoietin and vascular endothelial growth factor receptors in arterial endothelium

The Bmx gene, a member of the Tec tyrosine kinase gene family, is known to be expressed in subsets of hematopoietic and endothelial cells. In this study, mice were generated in which the first coding exon of the Bmx gene was replaced with the lacZ reporter gene by a knock-in strategy. The homozygous mice lacking Bmx activity were fertile and had a normal life span without an obvious phenotype. Staining of their tissues using beta-galactosidase substrate to assess the sites of Bmx expression revealed strong signals in the endothelial cells of large arteries and in the endocardium starting between days 10.5 and 12.5 of embryogenesis and continuing in adult mice, while the venular endothelium showed a weak signal only in the superior and inferior venae cavae. Of the five known endothelial receptor tyrosine kinases tested, activated Tie-2 induced tyrosyl phosphorylation of the Bmx protein and both Tie-2 and vascular endothelial growth factor receptor 1 (VEGFR-1) stimulated Bmx tyrosine kinase activity. Thus, the Bmx tyrosine kinase has a redundant role in arterial endothelial signal transduction downstream of the Tie-2 and VEGFR-1 growth factor receptors.

Electroporation-mediated transfer of cytokine genes into human esophageal tumors produces anti-tumor effects in mice

Electroporation facilitates transfer of chemicals or plasmid DNA from extracellular milieu into cells by increasing the permeability of the cell membrane. Delivery of electric pulses to established tumors thereby can improve the susceptibility of tumors to an anti-cancer agent administered. We examined whether electroporation-mediated transfer of cytokine genes into solid tumors could produce anti-tumor effects in the tumor-bearing mice. Plasmid DNA containing cytokine genes were injected into human esophageal T.Tn tumors developed in nude mice and electric pulses were then delivered. Administration of murine GM-CSF or human IL-2 gene followed by electroporation significantly suppressed the subsequent growth of T.Tn tumors and prolonged the survival of the inoculated mice. In contrast, electroporation-mediated introduction of a control gene, human GM-CSF gene, whose products do not bind to murine GM-CSF receptors, did not achieve any anti-tumor effects. In vivo transfection of cytokine genes with electroporation could be a possible therapeutic strategy for established solid tumors.

Gene therapy for cancer

The basic strategies for gene therapy that have been explored include immunogene therapy such as cytokine gene transfer, selective prodrug activation, so-called suicide genes, transfer of a tumor suppressor gene, and inhibition of activated oncogenes by antisense mechanisms. Many therapeutic protocols have so far been registered in the office of the Recombinant DNA Advisory Committee, NIH, as of June 1999. Regarding the basic research in gene therapy, we planned a clinical application of gene therapy for an esophageal cancer patient at our institution. We review herein the present status of gene therapy for cancer overseas, and describe a protocol of clinical trials for gene therapy for esophageal cancer at our institution.

Effects of high ELF magnetic fields on enzyme-catalyzed DNA and RNA synthesis in vitro and on a cell-free DNA mismatch repair

Environmental electromagnetic fields have been implicated in human cancers. We examined whether high extremely low frequency (ELF) AC magnetic fields could affect DNA synthesis, transcription or repair, using in vitro model systems with defined sequences. The rate and fidelity of DNA polymerase catalyzed DNA synthesis, as well as of RNA polymerase catalyzed RNA synthesis, were not statistically significantly affected by 60 Hz 0.25-0.5 Tesla magnetic fields. The efficiency of mutS dependent mismatch repair with human cell extracts was also not affected by the magnetic field exposure. The results suggest that the core processes related to the transmission of genetic information are stable under high ELF magnetic fields.

Combinatory anti-tumor effects of electroporation-mediated chemotherapy and wild-type p53 gene transfer to human esophageal cancer cells

Delivery of electric pulses to an established solid tumor augments the permeability of cell membrane and increases the susceptibility of tumors to an anti-cancer agent that is administered in the vicinity of tumors. Forced expression of the wild-type p53 gene in tumor cells that have non-functional p53 gene(s) can also enhance their sensitivity to a DNA-damaging agent. To investigate the feasibility of electroporation-mediated therapy for cancer, electric pulses were delivered to human esophageal tumors developed in nude mice after they received an anti-cancer agent and/or plasmid DNA containing the wild-type p53 gene. The growth of esophageal tumors was suppressed with electroporation-mediated chemotherapy compared with the treatment with an anti-cancer agent or electroporation alone. Intratumoral injection of the wild-type p53 gene into p53-mutated esophageal tumors followed by electroporation also inhibited tumor growth. When mice were administered with the wild-type p53 gene and an anti-cancer agent, subsequent electroporation produced a synergistic therapeutic effect. Combinatory transfer of plasmid DNA and a pharmacological agent by electroporation is thereby a possible therapeutic strategy for the treatment of solid tumors.

Serum p53 antibody is a useful tumor marker in superficial esophageal squamous cell carcinoma

BACKGROUND

Patients with superficial (mucosal or submucosal) esophageal carcinoma (SEC) have significantly better survival rates than patients with advanced carcinoma. Some patients with advanced esophageal carcinoma have been reported to test positive for serum p53 antibodies (Abs). Because very few patients with superficial carcinoma have been examined, the aim of this study was to evaluate the clinical significance of serum p53-Abs in patients with superficial esophageal squamous cell carcinoma (SESCC).

METHODS

Thirty-five consecutive patients with SESCC were studied for serum p53-Abs by enzyme-linked immunoabsorbent assay before and after treatment. The clinicopathologic features of p53 seropositive and p53 negative patients were compared. The relation between the presence of serum p53-Abs and p53 immunoreactivity of the resected specimens was examined. Three tumor markers (squamous cell carcinoma antigen [SCC-Ag], CYFRA21-1, and carcinoembryonic antigen [CEA]) were assessed to compare their sensitivities with serum p53-Abs.

RESULTS

Fourteen of 35 patients (40%) were p53 seropositive. Relatively few patients tested positive for the other tumor markers: CEA, 11.4%; SCC-Ag, 14.3%; CYFRA21-1, 5.7%. There were no significant correlations between clinicopathologic features and p53 seropositivity except for tumor location. A strong correlation between p53 immunostaining and the presence of serum p53-Abs was observed (P = 0.003). Of the 14 patients with seropositive results, 12 turned seronegative after resection, and the other 2 experienced disease recurrence.

CONCLUSIONS

Surveillance of serum p53-Abs is superior to the three tumor markers for detecting SESCC. This serum marker is also useful for the detection of p53 protein overexpression and for the monitoring of residual tumor cells.

Serum p53 antibody is a useful tumor marker in superficial esophageal squamous cell carcinoma

BACKGROUND

Patients with superficial (mucosal or submucosal) esophageal carcinoma (SEC) have significantly better survival rates than patients with advanced carcinoma. Some patients with advanced esophageal carcinoma have been reported to test positive for serum p53 antibodies (Abs). Because very few patients with superficial carcinoma have been examined, the aim of this study was to evaluate the clinical significance of serum p53-Abs in patients with superficial esophageal squamous cell carcinoma (SESCC).

METHODS

Thirty-five consecutive patients with SESCC were studied for serum p53-Abs by enzyme-linked immunoabsorbent assay before and after treatment. The clinicopathologic features of p53 seropositive and p53 negative patients were compared. The relation between the presence of serum p53-Abs and p53 immunoreactivity of the resected specimens was examined. Three tumor markers (squamous cell carcinoma antigen [SCC-Ag], CYFRA21-1, and carcinoembryonic antigen [CEA]) were assessed to compare their sensitivities with serum p53-Abs.

RESULTS

Fourteen of 35 patients (40%) were p53 seropositive. Relatively few patients tested positive for the other tumor markers: CEA, 11.4%; SCC-Ag, 14.3%; CYFRA21-1, 5.7%. There were no significant correlations between clinicopathologic features and p53 seropositivity except for tumor location. A strong correlation between p53 immunostaining and the presence of serum p53-Abs was observed (P = 0.003). Of the 14 patients with seropositive results, 12 turned seronegative after resection, and the other 2 experienced disease recurrence.

CONCLUSIONS

Surveillance of serum p53-Abs is superior to the three tumor markers for detecting SESCC. This serum marker is also useful for the detection of p53 protein overexpression and for the monitoring of residual tumor cells.

Serum p53 antibody is a useful tumor marker in superficial esophageal squamous cell carcinoma

BACKGROUND

Patients with superficial (mucosal or submucosal) esophageal carcinoma (SEC) have significantly better survival rates than patients with advanced carcinoma. Some patients with advanced esophageal carcinoma have been reported to test positive for serum p53 antibodies (Abs). Because very few patients with superficial carcinoma have been examined, the aim of this study was to evaluate the clinical significance of serum p53-Abs in patients with superficial esophageal squamous cell carcinoma (SESCC).

METHODS

Thirty-five consecutive patients with SESCC were studied for serum p53-Abs by enzyme-linked immunoabsorbent assay before and after treatment. The clinicopathologic features of p53 seropositive and p53 negative patients were compared. The relation between the presence of serum p53-Abs and p53 immunoreactivity of the resected specimens was examined. Three tumor markers (squamous cell carcinoma antigen [SCC-Ag], CYFRA21-1, and carcinoembryonic antigen [CEA]) were assessed to compare their sensitivities with serum p53-Abs.

RESULTS

Fourteen of 35 patients (40%) were p53 seropositive. Relatively few patients tested positive for the other tumor markers: CEA, 11.4%; SCC-Ag, 14.3%; CYFRA21-1, 5.7%. There were no significant correlations between clinicopathologic features and p53 seropositivity except for tumor location. A strong correlation between p53 immunostaining and the presence of serum p53-Abs was observed (P = 0.003). Of the 14 patients with seropositive results, 12 turned seronegative after resection, and the other 2 experienced disease recurrence.

CONCLUSIONS

Surveillance of serum p53-Abs is superior to the three tumor markers for detecting SESCC. This serum marker is also useful for the detection of p53 protein overexpression and for the monitoring of residual tumor cells.

Shiga toxin activates p38 MAP kinase through cellular Ca(2+) increase in Vero cells

We examined whether the mitogen-activated protein kinase (MAPK) pathway is involved in Shiga toxin (Stx)-induced Vero cell injury. Consonant with cell injury, Stx caused a transient extracellular signal-regulated kinase1/2 (ERK1/2) and a sustained p38 MAPK phosphorylation. p38 MAPK inhibitors (SB 203580 and PD 169316), but not an ERK1/2 kinase inhibitor (PD 98059), partially inhibited the Stx-induced cell death. BAPTA-AM, a Ca(2+) chelator, reduced both cell injury and p38 MAPK phosphorylation. Antioxidants reduced Stx1-induced p38 MAPK phosphorylation. These data indicate that Stx activates p38 MAPK through an increase in intracellular Ca(2+) and reactive oxygen species, and this signaling is involved in Stx-induced cell death.

Clinical benefits of steroid therapy on surgical stress in patients with esophageal cancer

BACKGROUND

Despite improvements in surgical techniques and perioperative care, severe complications lead to long hospital stays for some esophageal cancer patients. The purpose of this study was to evaluate the safety and effectiveness of perioperative steroid therapy on the postoperative clinical course.

METHODS

Fifty-seven patients operated for esophageal cancer in 1997 and 1998 were treated with perioperative steroid therapy. Fifty consecutive patients operated in 1995 and 1996 served as a control group. In the steroid group, each patient was given 250 mg of methylprednisolone intravenously before operation followed by 125 mg on postoperative days 1 and 2. Serum interleukin-6, polymorphonuclear cell elastase, and C-reactive protein levels, and the postoperative clinical course were compared between the groups.

RESULTS

Morbidity rates including hyperbilirubinemia, anastomotic leakage, and liver dysfunction were significantly lower in the steroid group than in the control group. Days until extubation and hospital stay were significantly shorter for the steroid group. Inflammatory mediators, body temperature, heart rate, and respiratory index after the surgical procedure were significantly lower in the steroid group. Adverse effects possibly caused by steroid therapy were not observed.

CONCLUSIONS

Perioperative steroid therapy was safe and effective for the inhibition of inflammatory mediators and the improvement of the postoperative clinical course of patients with esophageal cancer.

Loss of tumorigenicity of human breast cancer cells engineered to produce IL-2, IL-4 or GM-CSF in nude mice

Human breast cancer cells (OCUB-M), retrovirally transduced with granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin-2 (IL-2) or IL-4 gene were examined for their antitumor activities in nude mice. Although cell proliferation rates in vitro of these cytokine-producing cells were not significantly different from that of wild-type cells, nude mice that were subcutaneously inoculated with cytokine-producing cells did not develop tumors in contrast to mice that were injected with wild-type cells. Injection of GM-CSF-producing cells into the vicinity of growing wild-type tumors retarded subsequent growth of wild-type tumors. Histological examination of tumors which received GM-CSF-producing cells revealed marked infiltration of mononuclear cells around the tumors. Irradiation of cytokine-producing cells diminished their proliferation capacity but production of cytokine(s) was retained. Therefore, inoculation of irradiated cytokine producer cells into growing tumors can be used as a therapeutic maneuver for breast cancer.

Identification of Tek/Tie2 binding partners. Binding to a multifunctional docking site mediates cell survival and migration

The Tek/Tie2 receptor tyrosine kinase plays a pivotal role in vascular and hematopoietic development. To study the signal transduction pathways that are mediated by this receptor, we have used the yeast two-hybrid system to identify signaling molecules that associate with the phosphorylated Tek receptor. Using this approach, we demonstrate that five molecules, Grb2, Grb7, Grb14, Shp2, and the p85 subunit of phosphatidylinositol 3-kinase can interact with Tek in a phosphotyrosine-dependent manner through their SH2 domains. Mapping of the binding sites of these molecules on Tek reveals the presence of a multisubstrate docking site in the carboxyl tail of Tek (Tyr(1100)). Mutation of this site abrogates binding of Grb2 and Grb7 to Tek in vivo, and this site is required for tyrosine phosphorylation of Grb7 and p85 in vivo. Furthermore, stimulation of Tek-expressing cells with Angiopoietin-1 results in phosphorylation of both Tek and p85 and in activation of endothelial cell migration and survival pathways that are dependent in part on phosphatidylinositol 3-kinase. Taken together, these results demonstrate that Angiopoietin-1-induced signaling from the Tek receptor is mediated by a multifunctional docking site that is responsible for activation of both cell migration and cell survival pathways.

Differential efficacy of suicide gene therapy by herpes simplex virus-thymidine kinase gene reflects the status of p53 gene in human esophageal cancer cells

We examined the effect of herpes simplex virus-thymidine kinase gene (HSV-TK)-mediated suicide gene therapy on human esophageal cancer. Two human lines, T.Tn cells which bears truncated p53 and TE2 cells with wild-type p53, were transduced with the HSV-TK gene and tested for their sensitivities to a prodrug, ganciclovir (GCV). The transduced cells, T.Tn/TK and TE2/TK, increased in vitro sensitivity to GCV compared with that of respective wild-type cells. However, the growth suppression of T.Tn/TK tumors induced by GCV was marginal in nude mice and the tumors regrew thereafter. In contrast, the growth of TE2/TK tumors was significantly inhibited by GCV and all the tumors disappeared. The status of the p53 gene of tumor cells thereby may influence the efficacy of the HSV-TK/GCV system.

High serum levels of M-CSF and G-CSF in Kawasaki disease

To examine any role of macrophage colony-stimulating factor (M-CSF), in the immune responses in Kawasaki disease (KD), we serially assayed M-CSF and several related cytokines using ELISA. In 10 paediatric patients with KD the level of M-CSF was significantly higher in the acute phase than in the convalescent phase (1476.1 +/- 443.6 v 805.0 +/- 184.7 U/ml). Higher levels of serum granulocyte colony-stimulating factor (G-CSF) and interleukin-6 were also found in the acute phase. These results suggest that M-CSF, G-CSF and interleukin-6, derived from monocytes as monokines or derived from vascular endothelial cells, might play an important role in the acute phase of KD.

Expression of wild-type p53 gene confers increased sensitivity to radiation and chemotherapeutic agents in human esophageal carcinoma cells

The status of the p53 gene of tumor cells can modify the sensitivity of the tumors to radiation and anti-cancer agents. Human esophageal cancer cells (T.Tn) bearing mutated p53 gene were retrovirally transduced with wild-type p53 gene. The transduced cells (T.Tn/p53) which stably expressed wild-type p53 proliferated at the same rate as parental cells. However, the sensitivity to radiation was significantly improved by the transduction and T.Tn/p53 cells became markedly susceptible to cisplatin and etoposide compared with parental cells. Administration of cisplatin noticeably suppressed the growth of T.Tn/p53 tumors but not T.Tn tumors inoculated in nude mice. Forced expression of wild-type p53 gene thereby can increase the sensitivity to DNA damage in esophageal cells.

Identification and cloning of an Erwinia carotovora subsp. carotovora bacteriocin regulator gene by insertional mutagenesis

Avirulent Erwinia carotovora subsp. carotovora CGE234-M403 produces two types of bacteriocin. For the purpose of cloning the bacteriocin genes of strain CGE234M403, a spontaneous rifampin-resistant mutant of this strain, M-rif-11-2, was isolated. By Tn5 insertional mutagenesis using M-rif-11-2, a mutant, TM01A01, which produces the high-molecular-weight bacteriocin but not the low-molecular-weight bacteriocin was obtained. By thermal asymmetric interlaced PCR, the DNA sequence from the Tn5 insertion site and the DNA sequence of a contiguous 1,280-bp region were determined. One complete open reading frame (ORF), designated ORF2, was identified within the sequenced fragment. The 3' end of another ORF, ORF1, was located upstream of ORF2. A noncoding region and a putative promoter were located between ORF1 and ORF2. Downstream from ORF2, the 5' end of another ORF (ORF3) was found. Deduction from the nucleotide sequence indicated that ORF2 encodes a protein of 99 amino acids, which showed high homology with Yersinia enterocolitica Yrp, a regulator of enterotoxin (Y-ST) production; Escherichia coli host factor 1, required for Qbeta-replicase; and Azorhizobium caulinodans NrfA, required for the expression of nifA. ORF2 was designated brg, bacteriocin regulator gene. A fragment containing ORF2 and its promoter was amplified and cloned into pBR322 and pHSG415r, and the recombinant plasmids, pBYL1 and pHYL1, were transferred into E. coli DH5. Plasmid pBYL1 was reisolated and transferred into the insertion mutant TM01A01. Transformants carrying the plasmid, which was reisolated and designated pBYL1, re-produced the low-molecular-weight bacteriocin.

Endothelial receptor tyrosine kinases activate the STAT signaling pathway: mutant Tie-2 causing venous malformations signals a distinct STAT activation response

Endothelial receptor tyrosine kinases (RTKs) and their signaling mechanisms are of interest because they may control tumor angiogenesis and thereby tumor growth. In this report we have examined activation of the signal transducers and activators of transcription (STATs) by the three known vascular endothelial growth factor receptors (VEGFR1-3), as well as by the endothelial Tie-1 and -2 receptors. We also studied signaling by the R849W mutant of Tie-2 (MTie-2), which has been shown to cause venous malformations. When overexpressed in 293T cells, MTie-2 activated STAT1 while the other endothelial RTKs failed to do so. In contrast, the three VEGFRs were strong activators of STAT3 and STAT5, suggesting that they activate only a specific subset of these signal transducers. STAT3 and STAT5 were also activated by Tie-2 and, more so, by MTie-2. Tyrosine phosphorylation and DNA binding of STATs correlated with their ability to activate transcription as judged by luciferase assays. When co-expressed with STAT5, VEGFR-1 as well as both the Tie-2 receptor forms increased expression of the cell cycle inhibitor p21. Interestingly, co-expression of the Tie-2 receptors with STAT1 resulted in appearance of a novel, p21 related transcript. Taken together, these findings identify STAT proteins as novel targets for signal transduction by the endothelial RTKs, suggesting that they may be involved in the regulation of endothelial function.

Lymph node metastasis with adenocarcinoma of the gastric cardia: clinicopathological analysis and indication for D1 dissection

PURPOSE

To establish the indications for proximal resection with dissection of perigastric lymph nodes in order to treat adenocarcinoma of the gastric cardia.

METHODS

We analyzed the clinicopathological features of 110 resected adenocarcinomas of the gastric cardia with respect to the appropriate operative method and extent of lymphadenectomy for treatment.

RESULTS

Of the 110 patients, 93 underwent curative resection. The D2 group (total gastrectomy with dissection of extended regional lymph nodes) revealed higher morbidity and mortality rates compared to the D1 group (proximal resection with dissection of perigastric lymph nodes). The risk of lymph node metastasis was determined by depth of invasion, size of tumors, and gross findings of tumors.

CONCLUSION

The appropriate operative method for adenocarcinoma of the gastric cardia requires: (i) tumor size less than 4 cm; and (ii) gross findings indicating a superficial type of lesion, which are recommended for proximal resection with dissection of perigastric lymph nodes.

Antitumor response of genetically engineered IL-2 expression to human esophageal carcinoma cells in mature T cell-defective condition

We examined whether antitumor effect could be produced by retrovirally expressed human interleukin-2 (hIL-2) gene in human esophageal cancer cells (T.Tn) using immunocompromised nude mice. Loss of tumorigenicity of hIL-2-producing T.Tn (T.Tn/hIL-2) cells inoculated subcutaneously was observed in contrast to continuous tumor growth of wild-type cells, although in vitro proliferation of T.Tn/hIL-2 cells remained the same as that of wild-type cells. The antitumor effect was also evidenced by the injection of T.Tn/hIL-2 cells into established tumors of wild-type cells. The injection significantly retarded the subsequent growth of wild-type tumors. Histological examination of regressing T.Tn/hIL-2 cells revealed necrotic areas and infiltration of several types of inflammatory cells. Treatment of nude mice with anti-asialoGM1 antibody did not influence the IL-2-mediated tumor rejection. Vaccination of nude mice with irradiated T.Tn/hIL-2 cells whose secretion of hIL-2 in amount was comparable to that of unirradiated cells did not develop protective immunity. Taken together, the antitumor effect achieved in nude mice by the inoculation of T.Tn/hIL-2 cells is mediated by non-T non-natural killer cells.

Inhibition of peritoneal dissemination of murine colon carcinoma cells by administrating retrovirus harboring IL-2 gene

We have examined the antitumor effect of the retrovirally expressed interleukin-2 (IL-2) gene in murine colon carcinoma cells (Colon 26) on a disseminated model within the peritoneal cavity. Intraperitoneal injection of IL-2-producing Colon 26, but not wild-type cells, into syngeneic mice did not cause animal death and conferred T-cell-dependent, tumor-specific protective immunity on the inoculated mice. Direct administration of the retrovirus harboring IL-2 gene into the peritoneal cavity of the mice that had intraperitoneal tumor of wild-type cells significantly prolonged the survival of the mice compared with that of the mice that received control retrovirus. In the surviving mice treated with the retrovirus we also observed the induction of protective immunity with tumor specificity. Integrated retrovirus DNA was not detected in any organs examined. Thus, in vivo IL-2 gene transfer by retrovirus enabled tumor-bearing mice to generate antitumor immunity without unnecessary retroviral insertion into host genome.

Vascular endothelial growth factor B (VEGF-B) binds to VEGF receptor-1 and regulates plasminogen activator activity in endothelial cells

The vascular endothelial growth factor (VEGF) family has recently expanded by the identification and cloning of three additional members, namely VEGF-B, VEGF-C, and VEGF-D. In this study we demonstrate that VEGF-B binds selectively to VEGF receptor-1/Flt-1. This binding can be blocked by excess VEGF, indicating that the interaction sites on the receptor are at least partially overlapping. Mutating the putative VEGF receptor-1/Flt-1 binding determinants Asp63, Asp64, and Glu67 to alanine residues in VEGF-B reduced the affinity to VEGF receptor-1 but did not abolish binding. Mutational analysis of conserved cysteines contributing to VEGF-B dimer formation suggest a structural conservation with VEGF and platelet-derived growth factor. Proteolytic processing of the 60-kDa VEGF-B186 dimer results in a 34-kDa dimer containing the receptor-binding epitopes. The binding of VEGF-B to its receptor on endothelial cells leads to increased expression and activity of urokinase type plasminogen activator and plasminogen activator inhibitor 1, suggesting a role for VEGF-B in the regulation of extracellular matrix degradation, cell adhesion, and migration.