Relations of the c-myc gene and chromosome 8 in non-small cell lung cancer: analysis by fluorescence in situ hybridization

BACKGROUND

Amplification of the c-myc gene has been reported in non-small cell lung cancer (NSCLC). We investigated the c-myc gene amplification and the numerical aberration of chromosome 8 by dual color fluorescence in situ hybridization (FISH) to evaluate the relation between possible genetic abnormalities, pathological factors and prognosis.

METHODS

Tumor tissue samples were obtained from 31 patients with NSCLC who underwent lobectomy with mediastinal lymph node dissection. Samples were analyzed by FISH using 8 alpha satellite DNA probe and c-myc gene cosmid probe. The relation between genetic abnormalities, pathological factors (T factor, tumor size, and N factor), and prognostic factors was evaluated by univariate and multivariate analysis, and by the Kaplan-Meier method and log-rank analysis.

RESULTS

Chromosome 8 aberrations were T1 (n=3), 44.0%; T2 (n=18), 35.7%; T3 (n=7), 40.0%; T4 (n=3), 39.7% (p=NS). The c-myc gene amplifications were T1, 54.3%; T2, 51.1%; T3, 51.0%; T4, 66.3% (p=NS). There was no difference between patients whose tumor was more than 5 cm (n=16), and 5 cm or less (n=15) in the rate of chromosome 8 aberration (39.3%: 36.3%), or the rate of the c-myc gene amplification (52.1%: 53.7%). N factors for chromosome 8 aberrations were N0 (n=18), 35.9%; and N2 (n=11), 44.9% (p=NS). In the c-myc gene amplification, there was a significant difference between N0 and N2 (48.6%, 61.3%, p=0.040). In univariate and multivariate analysis, chromosome 8 aberrations correlated with a poor prognosis (p=0.037 and p=0.041). The 5-year survival rate was 15.4% in patients whose rate of chromosome 8 aberrations was 40% or more (n=13), which was significantly less than that in patients with an aberration rate of less than 40% (n=19, 57.9%, p=0.014).

CONCLUSION

The c-myc gene amplification correlates with lymph node metastasis. Although there was no significant link between the amplification of the c-myc gene and clinical outcome, the numerical chromosome 8 aberrations was considered to be a factor for survival.

Paraoxonase gene polymorphisms and plasma oxidized low-density lipoprotein level as possible risk factors for exudative age-related macular degeneration

PURPOSE

Paraoxonase (E.C.3.1.1.2) is a polymorphic protein shown to prevent low-density lipoprotein oxidation. Our purpose is to evaluate the hypothesis that paraoxonase gene polymorphisms and plasma oxidized low-density lipoprotein level play a role in the occurrence of exudative age-related macular degeneration.

METHODS

We analyzed paraoxonase genotypes (A/B, Gln-Arg192 and L/M, Leu-Met54) and plasma oxidized low-density lipoprotein levels in 72 unrelated Japanese patients with exudative age-related macular degeneration and compared the results with those of 140 age-matched and sex-matched control subjects.

RESULTS

The distribution of paraoxonase 192 and paraoxonase 54 polymorphisms was significantly different between the patients with age-related macular degeneration and control subjects (chi-square = 6.226, P =.0445, and chi-square = 6.863, P =.0323, respectively). The high frequency of the BB genotype at position 192 was observed in the exudative age-related macular degeneration group compared with control subjects (52.8% vs 35.0%, respectively; P =.0127). The high frequency of the LL genotype at position 54 was observed in the patients more than the controls (91.7% vs 77.1%, respectively; P =.0090). The mean (+/- SE) oxidized low-density lipoprotein levels in the patients was significantly higher than in the controls (19.1 +/- 1.0 vs 16.2 +/- 0.6 U/ml, P <.01).

CONCLUSION

These results indicate that the paraoxonase gene polymorphisms may represent a possible genetic risk factor for age-related macular degeneration and that increased plasma oxidized low-density lipoprotein may be involved in the pathogenesis of age-related macular degeneration.

High survival rate of 6 cases of pulmonary large cell neuroendocrine carcinoma formerly classified as small cell carcinoma

In the revised WHO classification of lung cancer, published in 1999, large cell neuroendocrine carcinoma (LCNEC) was employed as a new histological entity. LCNEC is generally considered a high-grade malignant lung cancer, and appropriate treatment remains to be determined. Before its new classification, LCNEC had long been classified into several entities. Advancing the review of previous cases in Nippon Medical School Hospital, we noticed that some LCNEC patients were formally diagnosed as having small cell lung cancer (SCLC), and they showed long-term survival.

MATERIAL AND METHODS

All histological specimens of surgically resected SCLC in Nippon Medical School Hospital were reclassified according to the 1999 WHO classification manual. Their neuroendocrine differentiations were confirmed by the use of immunostainings with chromogranin A and synaptophysin.

RESULTS

Fourteen cases satisfied the qualifications for both histological and clinical reevaluation. Among them, 6 patients were reclassified as LCNEC, and their stage distribution was as follow: IA; 1, IB; 2, IIIA; 2, and IIIB; 1. Their survival term ranged from 33.8 to 78.0 months; 5 were still alive, and 1 (IIIB) died 57.6 months after surgery.

DISCUSSION

According to this study, all the LCNEC patients who were treated as SCLC patients showed more favorable prognoses than patients described in published studies, even overall lung cancer. Therefore, it is suggested that multimodality therapy for SCLC may improve the prognoses of patients with LCNEC.

Stem cell factor protects c-kit+ human primary erythroid cells from apoptosis

OBJECTIVE

It has been reported that stem cell factor (SCF) promotes cell survival in primary cultured human erythroid colony-forming cells (ECFC). Given the heterogeneous nature of ECFC, which may affect interpretation of the data, we purified c-kit+ ECFC and investigated the specificity and mechanisms of the anti-apoptotic effects of SCF on these cells.

MATERIALS AND METHODS

Glycophorin A+ (GPA+) c-kit+ cells were purified from primary cultured ECFC derived from purified human CD34+ cells. The GPA+c-kit- and nonerythroid cells were generated from the same CD34+ cells. Apoptosis of ECFC was investigated in the absence or presence of SCF and erythropoietin (EPO) in serum-free medium. DNA fragmentation was measured with enzyme linked immunosorbent assay for oligonucleosome-sized DNA, gel electrophoresis, and annexin V labeling. Characterization of expanded cells and enriched cells was performed using multiparameter flow cytometry. For Akt assay, cells were lysed and the cleared lysates subjected to SDS-PAGE followed by Western blotting.

RESULTS

In GPA+c-kit+ cells, deprivation of cytokine caused rapid DNA fragmentation within 4 hours that reached a maximum at 6 hours. This was partially but clearly prevented by SCF or EPO. In contrast, no significant DNA fragmentation was seen in GPA+c-kit- and nonerythroid cells within 24 hours. PP2, a specific Src family kinase inhibitor, but not its inactive analogue PP3, reversed the anti-apoptotic effects of SCF. PP2 also inhibited SCF-induced phosphorylation of Akt.

CONCLUSION

These data indicate that SCF protects purified human GPA+c-kit+ cells from apoptosis and suggest that kit-mediated Src kinase activation is involved in Akt activation and cell survival.

[Experience of gamma-detecting probe for the survey of sentinel node in gastroesophageal malignancies]

Gamma-detecting probe NAVIGATOR GPS (Autosuture Japan) was evaluated by using of 99mTc. Linearlity of counting in radioactivity was fairly good, but the sensitivity of the prove is so low, that sentinel node (SN) should contain the 3.7 x 10(-3) MBq (0.1 microCi) of 99mTc or more for the most effective use of it. And the count rate of the gamma-detecting probe was influenced by the distance and angle from the 99mTc source variously. It is important for the operator to know such characteristics of the gamma-detecting probe in order to obtain the correct SN judging.

Neutral liposome-mediated delivery process of fluorescein-modified oligonucleotides in cultured human keratinocytes

We propose a model of the intracellular delivery process in which fluorescein-labeled natural oligonucleotides (F-DNA) are transferred into the nuclei of cultured human keratinocytes. By encapsulation in neutral multilamellar lecithin liposomes, the F-DNA appeared to be protected against intracellular interactions with cellular materials and nuclease attacks in the cytoplasm during the process. The intracellular behavior of F-DNA and fluorescent phospholipid-labeled liposomes was observed by means of fluorescence analysis. Results showed that: F-DNA encapsulated in neutral multilamellar liposomes reached the cellular nuclei more efficiently than either free F-DNA, or F-DNA in unilamellar liposomes; the liposomal membranes appeared to be left in the cytoplasm. The reaction of F-DNA with complementary DNA was suggested by a rapid quenching of the fluorescence in the nucleus. In addition, the fluorescence decrease was evidently suppressed in the cytoplasm, indicating a protective effect of the neutral multilamellar liposomes against the interaction of F-DNA with cytoplasmic materials. The application of these findings to 'photo'-antisense studies has been discussed, where suppression of a gene expression is attempted by using oligonucleotide-attached fluorescein with the aid of a photo-induced covalent binding property.

Free right internal thoracic artery as a second arterial conduit: modification of proximal anastomosis for improvement of graft patency

The applicability of the right internal thoracic artery (RITA) for coronary artery bypass grafting is higher when used as a free graft than as a pedicled graft. However, the technical difficulty of directly connecting the proximal end of the free RITA to the much larger aorta leads to poor patency. To overcome this technical limitation, we have used a modification that places the proximal end of this artery onto the hood of an accompanying vein graft at the aortic anastomosis instead of directly onto the aorta. We performed isolated coronary artery bypass grafting on 43 patients using the free RITA as a second arterial graft following pedicled left internal thoracic artery grafting. The mean patient age was 60 years and 38 patients were male. There was no mortality and no incidence of morbidity related to free RITA use. Postoperative coronary angiography performed in all patients revealed that all proximal anastomoses were widely patent, making the patency rate of the free RITA 100%. With these encouraging results, the free RITA graft with the described modification is thought to be a more promising second arterial graft with greater versatility than the pedicled graft. The long-term evaluation of a large patient population will determine the significance of this modification.

Screening of differentially expressed genes in 5-fluorouracil-resistant human gastrointestinal tumor cells

To identify genes differentially expressed in association with resistance to 5-fluorouracil (5FU), an mRNA differential display (DD) analysis was used to compare transcripts from the NUGC-3 human gastric tumor cell line and the NUGC-3 / 5FU / L line, which had acquired 208-fold resistance as a consequence of repeated exposure to escalating concentrations of 5FU. The 110 cDNA fragments differentially expressed in the DD analysis of either the NUGC-3 or NUGC-3 / 5FU / L cells were sequenced and subjected to a homology search, and 29 overexpressed and 22 underexpressed genes were identified in NUGC-3 / 5FU / L as a result. To confirm whether the changes in the gene expression levels in the NUGC-3 / 5FU / L cells were shared by other 5FU-resistant cells, 35 genes were analyzed by northern hybridization in 3 pairs of parent / 5FU-resistant human gastrointestinal tumor cell lines. The analysis revealed 20 overexpressed and 10 underexpressed genes in at least one of the three 5FU-resistant cells as compared with those in the parent cells. Among them, P-glycoprotein, equilibrative nucleoside transporter 1, and methylenetetrahydrofolate dehydrogenase were highly expressed in two of the three 5FU-resistant cells and cytidine deaminase and integrin alpha3 were underexpressed. The acquisition of resistance to 5FU by tumor cells may result from multiple changes in cellular functions.

Photosynthetic electron transport inhibition by pyrimidines and pyridines substituted with benzylamino, methyl and trifluoromethyl groups

The decrease of the number of ring nitrogen atoms of 2-benzylamino-4-methyl-6-trifluoromethyl-1,3,5-triazines on herbicidal activity and inhibition of photosynthetic electron transport (PET) was assayed using thylakoids from Spinacia oleracea or atrazine-resistant Chenopodium album. Three 2-benzylamino-4-methyl-6-trifluoromethyl-1,3,5-triazines, nine pyrimidines with a benzylamino-, methyl- and trifluoromethyl-group, 2-benzylamino-6-methyl-4-trifluoromethyl- pyridine and N-benzyl-3-methyl-5-trifluoromethylaniline were synthesized and assayed. 2-(4-Bromobenzylamino)-4-methyl-6-trifluoromethylpyrimidine exhibited the highest PET inhibitory activity against Spinacia oleracea thylakoids of all compounds tested. The 2-benzylaminopyrimidines and 2-methylpyrimidines having a 4-halobenzylamino group exhibited higher PET inhibition than atrazine and 2-trifluoromethylpyrimidines against Spinacia oleracea thylakoids. These PET inhibitory active compounds also exhibited a strong and similar inhibition both against atrazine-resistant Chenopodium album thylakoids as well as against thylakoids from wild-type Chenopodium. The herbicidal activity of 4-(4-bromobenzylamino)-2-methyl-6- trifluoromethylpyrimidine was equivalent to that of known herbicides like simetryne, simazine or atrazine.

Down-regulation in multiple human cancers of a novel gene, DMHC, from 17q25.1 that encodes an integral membrane protein

Frequent observations of allelic loss in chromosomal band 17q25.1 in a variety of human cancers have suggested that one or more tumor suppressor genes are present in that region. Moreover, a genetic locus for hereditary focal non-epidermolytic palmoplantar keratoderma, a condition associated with cancer of the esophagus (TOC; Tylosis with Oesophageal Cancer), lies in the same region. We screened cell lines derived from a variety of human cancers by reverse transcription-polymerase chain reaction (RT-PCR) to detect alterations in expression of genes within the region in question, by examining expressed sequence tags located there. These experiments identified an 1834-bp full-length cDNA encoding a novel, 441-amino acid integral membrane protein with seven putative transmembrane domains. This gene showed loss or extreme decrease of expression in 6 of 10 uterine cancer-cell lines, 2 of 11 hepatic cell carcinoma-cell lines, 2 of 7 lung cancer-cell lines, 1 of 6 gastric cancer-cell lines, and 1 of 10 breast cancer-cell lines. (We named it DMHC ("down-regulated in multiple human cancers").) Our results suggest that loss of expression of DMHC at 17q25.1 may play an important role in development of variety of human cancers.

Comparative study of the cyclization reactions of three bacterial cyclomaltodextrin glucanotransferases

The actions of cyclomaltodextrin glucanotransferases (CGTase; EC 2.4.1.19) from alkalophilic Bacillus sp. strain A2-5a (A2-5a CGTase), Bacillus macerans (Bmac CGTase), and Bacillus stearothermophilus (Bste CGTase) on amylose were investigated. All three enzymes produced large cyclic alpha-1,4-glucans (cycloamyloses) at the early stage of the reaction, but these were subsequently converted into smaller cycloamyloses. However, the rates of this conversion differed among the three enzymes. The product specificity of each CGTase in the cyclization reaction was determined by measuring the amount of each cycloamylose from CD6 to CD31 (CDn, a cycloamylose with a degree of polymerization of n). A2-5a CGTase produced 10 times more CD7, while Bmac CGTase produced 34 times more CD6 than other cycloamyloses. Bste CGTase produced 12 and 3 times more CD6 and CD7 than other cycloamyloses, respectively. The substrate specificities of the linearization reactions of CD6, CD7, CD8, and larger cycloamyloses (a mixture of CD22 to CD50) were investigated, and we found that CD7 and CD8 are extremely poor substrates for both hydrolytic and transglycosidic linearization (coupling) reactions while larger cycloamyloses are linearized at a much higher rate. By repeating these cyclization and linearization reactions, the larger cycloamyloses initially produced are converted into smaller cycloamyloses and finally into mainly CD6, CD7, and CD8. These three enzymes also differ in their hydrolytic activities, which seem to accelerate the conversion of larger cycloamyloses into smaller cycloamyloses.

Genetic pathways in the evolution of morphologically distinct colorectal neoplasms

Colorectal adenomas can be morphologically classified as exophytic or flat. Polypoid cancers and cancers arising de novo (ie., without any adenomatous component) might be the results of genetic progression from exophytic and flat adenomas, respectively. In this study, we examined 94 morphologically distinct neoplastic specimens for mutations in K-RAS and analyzed 10 microsatellite loci tightly linked to the tumor suppressor genes APC, p53, DCC/SMAD4, hMSH2, and hMLH1. K-RAS mutations were significantly associated with exophytic adenomas [11 of 21 (52%)] compared to flat adenomas [2 of 13(15%), P < 0.03] and polypoid cancers [17 of 25 (68%)] compared to cancers arising de novo [7 of 25 (28%), P < 0.01]. Two polypoid cancer cases demonstrated three and four different K-RAS mutations, respectively, suggesting multiple areas of clonal expansion. Cancers arising de novo were significantly associated with loss of heterozygosity (LOH) at chromosome 3p compared to pol ypoid cancers [6 of 18(33%) versus 1 of 20(5%), P < 0.03], whereas the prevalence of LOH at chromosomes 2p, 5q, 17p, and 18q and microsatellite instability were not different between the groups. For all cancers, LOH at chromosomes 17p and 18q occurred in 47 and 51%, respectively. However, LOH at 17p and 18q occurred in 0 and 16% of benign lesions, respectively, suggesting their role in malignant transformation. There was no difference in LOH at chromosomes 17p and 18q between exophytic and flat lesions. These findings suggest that (a) mutant K-RAS is associated with the exophytic growth of colonic neoplasms, and that (b) some colorectal cancers arising de novo lose chromosome 3p during their evolution, which is not seen in polypoid cancers. Half of all cancers lose chromosomes 17p and 18q at or near the malignant transition of benign lesions as reported previously, irrespective of morphology. There may be more than one genetic avenue for colorectal cancer formation, and this correlates with the morphological characteristics.

Changes in right ventricular performance in elderly patients who underwent lobectomy using video-assisted thoracic surgery for primary lung cancer

OBJECTIVE

Even though lobectomy using video-assisted thoracic surgery for primary lung cancer has been reported to be beneficial in terms of the perioperative outcome, changes in the right ventricular performance have not yet been reported. The aim of this study was to determine whether lobectomy by video-assisted thoracic surgery is also advantageous with respect to the right ventricular performance in elderly patients who are 70 years old or older.

SUBJECTS AND METHODS

Thirteen patients (mean age: 76 years) who underwent lobectomy using video-assisted thoracic surgery (Video-assisted Thoracic Surgery Group), and 10 patients (mean age: 76 years) who underwent lobectomy using a standard thoracotomy as a historical control group (Standard Thoracotomy Group) were studied. The hemodynamics and right ventricular ejection fraction were evaluated preoperatively, and at 6, 12, 24, and at 48 hours postoperatively.

RESULTS

Postoperative values were expressed as a percentage of the preoperative values. The systemic vascular resistance index decreased to a greater extent in the Video-assisted Thoracic Surgery Group than in the Standard Thoracotomy Group. The pulmonary arteriolar resistance index at 24 hours postoperation tended to be higher in the Standard Thoracotomy Group than in the Video-assisted Thoracic Surgery Group. The stroke index, cardiac index, and right ventricular ejection fraction at 24 hours postoperation were each significantly higher in the Video-assisted Thoracic Surgery Group than in the Standard Thoracotomy Group.

CONCLUSION

Lobectomy using video-assisted thoracic surgery for elderly patients offers not only beneficial effects in the right ventricular afterload but also acceleration in the expected compensatory hyperdynamics during the acute postoperative phase.

Improvement of desulfurization activity in Rhodococcus erythropolis KA2-5-1 by genetic engineering

Rhodococcus erythropolis KA2-5-1 can desulfurize dibenzothiophene (DBT) into 2-hydroxybiphenyl. A cryptic plasmid, pRC4, which was derived from R. rhodochrous IFO3338, was combined with an Escherichia coli vector to construct an E. coli-Rhodococcus shuttle vector. The complete nucleotide sequence of 2582-bp pRC4 was analyzed. Based on the characteristics of its putative replication genes, pRC4 was assigned to the family of pAL5000-related replicons. The desulfurization gene cluster, dszABC, and the related reductase gene, dszD, cloned from KA2-5-1, were reintroduced into KA2-5-1 and efficiently expressed. The DBT desulfurization ability of the transformant carrying two dszABC clusters and one dszD on the vector was about 4-fold higher than that of the parent strain, and the transformant also showed improved desulfurization activity for light gas oil (LGO). Sulfur components in LGO before and after the reaction were analyzed with gas chromatography-atomic emission detection.

A search for Drosophila neural precursor genes identifies ran

The Drosophila ran gene has been isolated in a differential cDNA screen designed to identify genes that are dynamically expressed in embryonic neuroblasts. The guanine triphosphate (GTP)-binding Ran protein, a member of the Ras superfamily, has been shown to participate in a variety of transport related processes in other organisms. Drosophila ran codes for a 216 amino acid (aa) protein that shares 78% and 86% identity with the yeast and human Ran proteins, respectively. Database searches have identified a second Drosophila ran gene, ran-like. The predicted Ran-like protein shares 59% identity with its isoform. Embryo in situ mRNA localization of ran and ran-like expression reveals that both are maternally expressed; however zygotic ran expression is restricted to central nervous system (CNS) neuroblasts undergoing late lineage formation, while ran-like expression is detected in the developing trachea and salivary gland. To investigate the significance of ran-restricted CNS expression, we have targeted its misexpression to different temporal windows of CNS development. In addition, a dominant-negative mutant form of ran was targeted to the developing CNS and to the larval eye/antenna imaginal disc to assess the role of ran-dependent functions. Embryonic CNS misexpression of the mutant, but not wild-type, ran results in larval death. Neither wild-type nor mutant ran misexpression had any detectable effect on embryonic CNS lineage specification, nuclear transport of a number of CNS-specific transcription factors or axonal guidance. However, expression of the dominant-negative mutant ran in the developing eye/antenna disc did result in a severe adult eye phenotype marked by apoptosis of photoreceptor, cone and pigment cells.

A possible role for lamivudine as prophylaxis against hepatitis B reactivation in carriers of hepatitis B who undergo chemotherapy and autologous peripheral blood stem cell transplantation for non-Hodgkin's lymphoma

Hepatitis B virus (HBV) reactivation, a well-known complication in immunosuppressed patients, can give rise to acute hepatitis and even fatal fulminant hepatitis. Three Japanese males with non-Hodgkin's lymphoma (NHL) who were carriers of HBV received high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT). To prevent HBV reactivation, all received oral lamivudine (150 mg/day), a nucleoside analogue, at the start of chemotherapy. All were treated at full-dose intensity, including corticosteroids, without modification of treatment regimens. All three patients completed the total course of chemotherapy and PBSCT, with no signs of HBV reactivation. Peripheral blood stem cell (PBSC) harvests and hematological recoveries after transplantation were not affected by lamivudine, which was continued for at least 16 weeks after transplantation. HBV-DNA and DNA polymerase levels remained negative/normal after discontinuation of lamivudine. Lamivudine effectively inhibits HBV replication and has few serious adverse effects, particularly those related to hematopoiesis. Thus, prophylactic use of lamivudine from initiation of chemotherapy deserves consideration in the treatment of HBV carriers who require immunosuppressive chemotherapy, and may prevent HBV reactivation.

A simple objective parameter for perfusion study of renal transplant

We proposed a simple parameter, the kidney-to-aorta ratio (KAR), for evaluation of renal transplant perfusion. KAR was calculated from the peak counts of the kidney and the aorta. The calculated values were compared with the visual interpretation of the radionuclide first-pass flow study, percent renal uptake (%RU), and tubular extraction rate (TER) by Bubeck's one point sampling method in 37 studies. KAR correlated well with the visual interpretation of the flow study and the other quantitative parameters. Representative cases, which showed the usefulness of KAR for the objective assessment of the perfusion status of renal transplants, were presented. In conclusion, KAR is a simple and practically useful parameter for objective evaluation and follow-up of renal transplant perfusion.

Investigation of Corneal Autofluorescence in Diabetic Patients

Purpose: The investigation of corneal autofluorescence in diabetic patients.Objects and Methods: Corneal autofluorescence was investigated with a newly-developed fluorophotometer (wave length: excitation, 290-390 nm; emission, 430-630 nm) having, fluorescence characteristics involving those of reduced pyridine nucleotides (PN) and advanced glycation endoproduct (AGE) except pentosidine and pyrraline. Twenty-eight patients with non-insulin-dependent diabetes mellitus and sixty-seven healthy volunteers were studied.Results: The corneal autofluorescence was 1.65 times higher than that of controls (P <.0001). In non-insulin-dependent diabetes mellitus, the corneal autofluorescenece was not correlated significantly with various diabetic parameters in blood (r < 0.4). In controls, the corneal autofluorescence was correlated significantly with age (r = 0.438).Conclusion: The corneal autofluorescence has some relation with PN and AGE accumulation in the cornea.

Stem cell factor prevents Fas-mediated apoptosis of human erythroid precursor cells with Src-family kinase dependency

The Fas ligand (Fas-L) expressed on mature erythroblasts may induce apoptosis of more immature erythroid cells that express Fas, whereas stem cell factor (SCF) may prevent Fas-mediated cell death in hematopoietic progenitor cells. The manner in which SCF prevents Fas-mediated cell death still is unclear. Given the essential role of SCF and the potentially important involvement of the Fas/Fas-L system in the development of erythrocytes, we studied mechanisms related to SCF prevention of Fas-mediated apoptosis. We used primary cultured human erythroid colony-forming cells (ECFC) derived from CD34+ cells and enriched glycophorin A positive (GPA+) c-kit+ cells in ECFC. Apoptosis of ECFC was induced by an Fas-L mimetic monoclonal antibody CH11. DNA fragmentation and the activation of caspase-3 and caspase-8 were measured using commercially available kits. Characterization of expanded cells was performed using multiparameter flow cytometry. Lyn kinase activity was measured by enolase kinase assays. SCF inhibited the CH11-induced DNA fragmentation of ECFC as well as enriched GPA+ c-kit+ cells in ECFC, but not those of GPA+ c-kit- cells. SCF also inhibited the activation of caspase-3 and caspase-8, without downregulation of the surface expression of Fas, suggesting that SCF prevents apoptosis through uncoupling of Fas ligation from subsequent caspase activation. PP2, a specific inhibitor of Src-family kinases, antagonized the effects of SCF in preventing Fas-mediated apoptosis. We propose that SCF prevents Fas-mediated apoptosis of erythroid progenitor cells in a manner dependent on the activity of Src-family tyrosine kinases. We also identified active Lyn in erythroid cells. These data suggest the presence of a novel Src-family-dependent function of SCF in the development of erythrocytes.

Surgical treatment for a ruptured thoracic aortic aneurysm

OBJECTIVE

The treatment for a ruptured thoracic aortic aneurysm remains controversial. This study was undertaken to assess the outcome from surgery.

METHODS

Between 1993 and 1998, we have performed 19 operations for a ruptured thoracic aortic aneurysm. Patients with an impending rupture or a chronic false aneurysm were excluded. There were 11 men and 8 women, with a mean age of 70.5 +/- 6.7 years. The aneurysm was caused by dissection in 8 patients. Of these, 7 were acute (Stanford type A, 6; type B, 1), and the other one was chronic (type B). Aortic rupture occurred into the pericardial cavity (n = 7), into the left lung (n = 6), the mediastinum (n = 3), the pleural cavity (n = 2), or into the esophagus (n = 1). Severely unstable hemodynamics were noted in 12 patients with a rupture into the pericardium, mediastinum, or pleural cavity (Group A). Inotropic support was required in each of these patients. Metabolic acidosis developed all but 1 patient. The 7 patients with a rupture into the lung or esophagus coughed or vomited blood (Group B). The operative approach was anterior (n = 17) or lateral (n = 2). Grafts were placed in the ascending aorta (n = 4), ascending and transverse arch aorta (n = 7), transverse arch aorta (n = 3), or in the descending thoracic aorta (n = 5). Selective cerebral perfusion was used in 13 patients.

RESULTS

There were 5 hospital deaths (26.3%). The postoperative complications included central nervous system dysfunction (n = 3), low cardiac output syndrome or cardiac arrhythmias (n = 3), respiratory failure (n = 4), acute renal failure (n = 1), and local or systemic infections (n = 4). The perioperative event-free rate was 36.8% overall, 25% in Group A, and 57.1% in Group B.

CONCLUSIONS

Patients with unstable hemodynamics require prompt operative intervention. Rupture into the esophagus is associated with a high mortality rate. Rupture in a thoracic aortic aneurysm can be successfully treated with emergency surgery.

Effective cancer targeting using an anti-tumor tissue vascular endothelium-specific monoclonal antibody (TES-23)

Immunoconjugate targeting of solid tumors has not been routinely successful because the endo-thelial cells of blood vessels act as a physical barrier against the transport of macromolecules, such as antibodies. In the present study, we attempted to achieve tumor vascular targeting with an anti-tumor tissue endothelium-specific monoclonal antibody (TES-23). TES-23, an IgG1 monoclonal antibody raised against rat KMT-17 fibrosarcoma-derived endothelial cells, was covalently conjugated with neocarzinostatin (NCS) in a previous study. The TES-23-NCS conjugate induced tumor hemorrhagic necrosis, and showed marked anti-tumor effects against rat KMT-17 fibrosarcoma. This result prompted us to investigate whether this approach would be applicable to various other types of solid tumors. One hour after injection of (125)I-labeled TES-23 into BALB / c mice bearing Meth-A fibrosarcoma and Colon 26 adenocarcinoma, the tumor accumulation of TES-23 was greater than that of the control IgG. In the present study, we report the anti-tumor effects of this monoclonal antibody in mice bearing Meth-A fibrosarcoma. Mice treated with the immunoconjugate showed improved survival with no side effects. This result indicates that common antigens may be found in different kinds of tumor endothelial cells, and that TES-23 might recognize these antigens.

Synthesis of novel heterobranched beta-cyclodextrins from alpha-D-mannosylmaltotriose and beta-cyclodextrin by the reverse action of pullulanase, and isolation and characterization of the products

Alpha-D-mannosyl-maltotriose (Man-G3) were synthesized from methyl alpha-mannoside and maltotriose by the transfer action of alpha-mannosidase. (Man-G3)-betaCD and (Man-G3)2-betaCD were produced in about 20% and 4% yield, respectively when Aerobacter aerogenes pullulanase (160 units per 1 g of Man-G3) was incubated with the mixture of 1.6 M Man-G3 and 0.16 M betaCD at 50 degrees C for 4 days. The reaction products, (Man-G3)-betaCD were separated to three peaks by HPLC analysis on a YMC-PACK A-323-3 column and (Man-G3)2-betaCD were separated to several peaks by HPLC analysis on a Daisopak ODS column. The major product of (Man-G3)-betaCDs was identified as 6-O-alpha-(6(3)-O-alpha-D-mannosylmaltotriosyl)-betaCD by FAB-MS and NMR spectroscopies. The structures of (Man-G3)2-betaCDs were analyzed by TOF-MS and NMR spectroscopies, and confirmed by comparison of elution profiles of their hydrolyzates by alpha-mannosidase and glucoamylase on a graphitized carbon column with those of the authentic di-glucosyl-betaCDs. The structures of three main components of (Man-G3)2-betaCDs were identified as 6(1),6(2)-, 6(1),6(3)- and 6(1),64-di-O-(63-O-alpha-D-mannosyl-maltotriosyl)-betaCD.