Organ-specific expression of the intestinal epithelium-related antigen A33, a cell surface target for antibody-based imaging and treatment in gastrointestinal cancer

Murine monoclonal antibody A33 (mA33) was developed by the Memorial Sloan-Kettering Cancer Center and by the New York Branch of the Ludwig Institute for Cancer Research. It is an immunoglobulin (Ig)G2a antibody that detects a protease- and neuraminidase-resistant, periodate-sensitive epitope. Serological analysis of the antigen showed that it is expressed in a few colorectal cancer cell lines and a pancreatic cancer cell line, but is basically not reactive with other types of cell line. Normal fibroblasts and normal kidney cell lines reacted negatively to mA33. Immunohistochemical study of normal tissues identified the large and small intestinal mucosa as the principal site of A33 expression. Tests in tumor samples demonstrated that only tumors of the gastrointestinal tract are consistently A33 positive. A33 is found in 95% of primary and metastatic colorectal cancers, with uniform expression throughout the tumors in most cases. A33 is also detected in 63% of gastric cancers, with uniform expression in 45% of cases. Eighty-three percent of intestinal-type gastric cancers were positive for A33, and about 50% of the diffuse-type and mucinous cancers were mA33 positive. A33 was expressed in 50% of the pancreatic cancers but with marked heterogeneity. Other epithelial cancers, sarcomas, neuroectodermal tumors, and lymphoid neoplasms were generally A33 negative. A33 is the first example of a constitutively expressed, organ-specific epithelial membrane antigen permitting highly specific tumor targeting in patients with gastrointestinal cancer. Encouraged by the success of the biodistribution and imaging characteristic studies performed at Memorial Sloan-Kettering Cancer Center by the New York Branch of the Ludwig Institute in colorectal cancers, a new clinical study of humanized monoclonal antibody huA33 against A33 antigen-positive gastric cancers has been initiated in Japan.

SEREX analysis of gastric cancer antigens

Stomach cancer is the major malignancy in Japan and one of the most common cancers worldwide. To establish the basis for an immunotherapeutic approach to stomach cancer, we have initiated an analysis of stomach cancer antigens recognized by human immunoglobulin G (IgG) antibodies using SE-REX, a powerful expression cloning method developed by Dr. M. Pfreundschuh's group. Five stomach cancer cDNA libraries have been screened with autologous patient sera: one moderately differentiated adenocarcinoma; two poorly differentiated adenocarcinomas; and two scirrhous-type poorly differentiated adenocarcinomas of Borrmann type 4, the most devastating form of stomach cancer. Based on the reactivities of clones with autologous IgG antibodies, an average of 50 independent clones from each library and a total of 297 clones were isolated. DNA sequencing revealed that these 297 clones were derived from 136 different genes. Comparison of the 136 genes to sequences in DNA databases showed that 95 are previously identified genes and 41 are newly identified in this study. The antigens are derived from various genes including a chimeric gene between E-cadherin and an unknown gene Y, AKT oncogene, genes overexpressed in stomach cancers, genes of which the transcripts are alternatively or aberrantly spliced, and genes known to be involved in autoimmune diseases. Thus stomach cancer patients can generate an immune response against a surprisingly diverse set of gene products. To identify antigens potentially useful in the diagnosis and therapy of gastric cancer, all 136 genes were tested for their reactivities with a panel of sera from 44 gastric cancer patients (17 women and 27 men, aged 35-81 years) and with a panel of sera from 100 control individuals with no previous history of cancer but some of whom had gastritis (55 women and 45 men, aged 30-69 years). Eleven antigens showed reactivity only with a certain proportion of cancer patient sera but not with any control sera. An additional 12 antigens elicited antibody production at a much higher frequency in cancer patients than in control individuals. To evaluate the clinical usefulness of these antigens we are now examining their expression in normal and malignant tissues.

The ratio of splicing variants of MGC-24/CD164, a sialomucin, correlates with the metastatic potential of colorectal carcinomas

MGC-24/CD164 is a sialomucin expressed in many normal and cancerous tissues. In humans, soluble and transmembrane forms of MGC-24 are produced by alternative splicing. The total MGC-24 RNA level was found to be lower in human colorectal carcinomas as compared with the adjacent normal mucosal tissues. Lower MGC-24 mRNA levels in colon carcinomas and in the adjacent normal mucosa epithelium correlate with lymphatic vessel invasion by the carcinoma. The ratio of the soluble form to the transmembrane form of the mRNA in colorectal carcinomas was determined by ribonuclease protection assay. Higher ratios were correlated with less venous invasion and less remote metastasis, which became evident during postoperative observation.

Menaquinol oxidase activity and primary structure of cytochrome bd from the amino-acid fermenting bacterium Corynebacterium glutamicum

Cytochrome d was spectroscopically detected in membrane fractions of the amino-acid-fermenting, high-G+C gram-positive bacterium Corynebacterium glutamicum. Inhibition of NADH oxidase activity in the membranes by cyanide suggested that the main terminal respiratory oxidase during the stationary phase was a type of cytochrome bd. Cytochrome bd-type quinol oxidase, purified from the membranes, was composed of two subunits. Its reduced form showed absorption peaks at 627, 595, and 560 nm, which were due to haem d, high-spin protohaem, and low-spin protohaem, respectively. The air-oxidised form showed a peak at 645 nm, which might be due to oxygenated ferrous haem d. The spectral features and the size of subunit I are more similar to the properties of cytochromes bd from Proteobacteria, such as Escherichia coli, than to those of cytochrome bd from low-G+C gram-positive bacteria, such as Bacillus stearothermophilus. The menaquinol oxidase activity of the purified cytochrome bd was low, but was enhanced about fivefold by pre-incubating the enzyme with menaquinones. The order of effectiveness of quinols as oxidase substrates was clearly different from that of quinones as the activators of enzyme activity. Furthermore, activation was destroyed by ultraviolet irradiation of the pre-incubated enzyme and then restored by a second incubation with menaquinone. These results indicate that the enzymatic properties of this new oxidase are more similar to the properties of cytochromes bd from low-G+C gram-positive bacterial than to those of proteobacterial counterparts. They also suggest that the enzyme has a second quinone-binding site essential for full activity, in addition to the active centre for substrate oxidation. By using probes based on partial peptide sequences of the subunits, the genes for the two subunits of C. glutamicum cytochrome bd were cloned. The deduced amino acid sequence demonstrated that subunit I lacks the C-terminal half of the Q loop and that the primary structure of C. glutamicum cytochrome bd is more similar to that of other gram-positive bacteria than to proteobacterial cytochromes bd.

Saturation transfer ratio imaging in invasive ductal carcinomas of the breast

A prospective study was performed to investigate the correlations between saturation transfer ratio (STR) and histologic parameters of invasive ductal carcinomas in human breast. The histologic parameters investigated were the extent of fibrosis in the intercellular matrix, dysplastic changes of nuclei, and mitotic index. Twenty-seven patients with breast carcinoma were examined using an off-resonance saturation pulse in conjunction with conventional field-echo T(1)-weighted imaging at frequency offsets of 448 Hz and 1200 Hz from water resonance. The values of STR at frequency offset of 1200 Hz (STR(1200)) increased from non-scirrhous carcinoma to scirrhous carcinoma. Although STR(1200) showed correlation with the extent of fibrosis in the intercellular matrix (p<0.01, n = 27), they did not correlate with the dysplastic changes of nuclei or mitotic index. On the other hand, the values of STR at frequency offset of 448 Hz (STR(448)) demonstrated close correlation to dysplastic changes of nuclei and mitotic index (p<0.01, n = 27). STR(1200) correlates with the structural characteristics and STR(448) correlates with the nature of malignant cells with regard to nuclear dysplasia and mitotic potential.

A phase III randomized study comparing doxifluridine and 5-fluorouracil as supportive chemotherapy in advanced and recurrent gastric cancer

We conducted a phase III randomized study to investigate effects of supportive chemotherapy with oral doxifluridine (group A, 75 patients) or 5-fluorouracil (group B, 75 patients) in advanced gastric cancer when intensive chemotherapy was not an option. Although there were no significant differences between the groups with regard to survival, hospital-free survival and time to progression, median values of 3 endpoints were superior in group A. Secondary analysis showed that group A patients with prior chemotherapy tended to have longer survival and hospital-free survival and significantly longer time to progression.

Energy-yielding properties of SoxB-type cytochrome bo(3) terminal oxidase: analyses involving Bacillus stearothermophilus K1041 and its mutant strains

We isolated a K17q8 mutant from K17 mutant cells of Bacillus stearothermophilus which contain SoxB-type cytochrome bo(3) as well as cytochrome bd but not SoxM-type cytochrome caa(3), which is the main terminal oxidase in B. stearothermophilus K1041. The respiration of K17q8 was highly sensitive to as little as 10 microM cyanide, indicating that the main terminal oxidase is cytochrome bo(3). The aerobic growth yield of K17q8 was lower than that of wild-type K1041, but higher than that of parental K17. The H(+)/O ratio of K17q8 was about 5, i.e. a little lower than the 6.1-6.5 of K1041, but higher than the 2.9-3.1 of K17 [Sone et al. (1999) J. Biosci. Bioeng. 87, 495-499]. Analyses of membrane fragments indicated that K17q8 contains about 0.2 nmol cytochrome bo(3) per mg membrane protein, and scarcely any subunits of cytochromes caa(3) and bd. From the membrane fraction of K17q8, cytochrome bo(3) was purified and shown to be composed of two subunits with apparent molecular masses of 56 and 19 kDa. The enzyme contained protoheme IX and heme O, as the main low-spin heme and high-spin heme. Analysis of the substrate specificity indicated that the high-affinity site is very specific to cytochrome c-551, a cytochrome c which is a membrane-bound lipoprotein of thermophilic Bacillus. The I(50) of purified cytochrome bo(3) was determined to be 4 microM, indicating that cytochrome bo(3) among the three terminal oxidases in B. stearothermophilus was most susceptible to cyanide. The respiration of K17q8 was mostly inhibited by the addition of cyanide at this concentration.

Contribution of malonyl-CoA decarboxylase to the high fatty acid oxidation rates seen in the diabetic heart

Myocardial glucose oxidation is markedly reduced in the uncontrolled diabetic. We determined whether this was due to direct biochemical changes in the heart or whether this was due to altered circulating levels of insulin and substrates that can be seen in the diabetic. Isolated working hearts from control or diabetic rats (streptozotocin, 55 mg/kg iv administered 6 wk before study) were aerobically perfused with either 5 mM [(14)C]glucose and 0.4 mM [(3)H]palmitate (low-fat/low-glucose buffer) or 20 mM [(14)C]glucose and 1.2 mM [(3)H]palmitate (high-fat/high-glucose buffer) +/-100 microU/ml insulin. The presence of insulin increased glucose oxidation in control hearts perfused with low-fat/low-glucose buffer from 553 +/- 85 to 1,150 +/- 147 nmol x g dry wt(-1) x min(-1) (P < 0. 05). If control hearts were perfused with high-fat/high-glucose buffer, palmitate oxidation was significantly increased by 112% (P < 0.05), but glucose oxidation decreased to 55% of values seen in the low-fat/low-glucose group (P < 0.05). In diabetic hearts, glucose oxidation was very low in hearts perfused with low-fat/low-glucose buffer (9 +/- 1 nmol x g dry wt(-1) x min(-1)) and was not altered by insulin or high-fat/high-glucose buffer. These results suggest that neither circulating levels of substrates nor insulin was responsible for the reduced glucose oxidation in diabetic hearts. To determine if subcellular changes in the control of fatty acid oxidation contribute to these changes, we measured the activity of three enzymes involved in the control of fatty acid oxidation; AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), and malonyl-CoA decarboxylase (MCD). Although AMPK and ACC activity in control and diabetic hearts was not different, MCD activity and expression in all diabetic rat heart perfusion groups were significantly higher than that seen in corresponding control hearts. These results suggest that an increased MCD activity contributes to the high fatty acid oxidation rates and reduced glucose oxidation rates seen in diabetic rat hearts.

Over-expression of cbaAB genes of Bacillus stearothermophilus produces a two-subunit SoxB-type cytochrome c oxidase with proton pumping activity

We constructed expression plasmids containing cbaAB, the structural genes for the two-subunit cytochrome bo(3)-type cytochrome c oxidase (SoxB type) recently isolated from a Gram-positive thermophile Bacillus stearothermophilus. B. stearothermophilus cells transformed with the plasmids over-expressed an enzymatically active bo(3)-type cytochrome c oxidase protein composed of the two subunits, while the transformed Escherichia coli cells produced an inactive protein composed of subunit I without subunit II. The oxidase over-expressed in B. stearothermophilus was solubilized and purified. The oxidase contained protoheme IX and heme O, as the main low-spin heme and the high-spin heme, respectively. Analysis of the substrate specificity indicated that the high-affinity site is very specific for cytochrome c-551, a cytochrome c that is a membrane-bound lipoprotein of thermophilic Bacillus. The purified enzyme reconstituted into liposomal vesicles with cytochrome c-551 showed H(+) pumping activity, although the efficiency was lower than those of cytochrome aa(3)-type oxidases belonging to the SoxM-type.

Reperfusion arrhythmias in the murine heart: their characteristics and alteration after ischemic preconditioning

In this study, we examined the features of reperfusion arrhythmias and the effect of preconditioning (PC) in the mouse for future application of genetically engineered mice to study mechanisms of this type of arrhythmia. Under pentobarbital anesthesia, reperfusion arrhythmias were induced by temporary occlusion of the left anterior descending coronary artery and reperfusion in BALB/c AJc1 mice. In the first protocol, the coronary artery was occluded for periods ranging from 2 to 15 min and then reperfused. In the second protocol, hearts were preconditioned with 2- or 3-min ischemia and 5-min reperfusion prior to the 5 min of coronary occlusion. An electrocardiogram was recorded throughout the experiment, and arrhythmias were diagnosed according to the Lambeth Convention criteria. The incidences of reperfusion-induced ventricular tachycardia (VT) in hearts that received 2, 3, 5, 10 and 15-min ischemia (n = 10 approximately 14) were 0, 9, 73, 55 and 30 %, respectively. Ventricular fibrillation (VF) was not observed upon reperfusion regardless of the ischemia duration. PC with 2-min ischemia and with 3-min ischemia (n = 10 for each PC) reduced the incidences of reperfusion VT after 5-min ischemia to 40% and 10%, respectively. However, in mice that developed reperfusion VT, the VT duration was similar to that in non-preconditioned controls, ranging from 1 to 16 s. These results suggest that the relationship between ischemia duration and incidence of VT upon subsequent reperfusion is "bell shaped" and that PC has anti-arrhythmic effects in the mouse, as it does in anesthetized rat hearts. However, there appear to be differences in the incidence of reperfusion-induced VF and the duration of reperfusion VT between these species. Thus, the present murine preparation appears to be a useful model for studying the mechanism of reperfusion VT and PC, though it does not share all of the features of reperfusion arrhythmias with the anesthetized rat preparation.

Effects of nafamostat mesilate, a synthetic protease inhibitor, on immunity and coagulation after hepatic resection

BACKGROUND/AIMS

Effects of nafamostat mesilate (NM), a serine protease inhibitor, on both coagulation-fibrinolysis activity and post-operative changes in immune responsiveness were investigated in a clinical study of 20 patients who underwent an extensive hepatic resection.

METHODOLOGY

The patients were randomly allocated into 2 groups of 10 patients each: The NM group was administered nafamostat mesilate (2 mg/kg/day) during and after the operation for 7 days. The control group received standard post-operative intensive therapies except NM.

RESULTS

The post-operative increase in coagulation in the control group was significantly suppressed in the NM-treated group on post-operative day (POD) 7. Natural killer (NK) activity, which was impaired after the operation, was recovered in the NM group on POD 7 and was significantly higher than in the control group. Helper/suppressor ratios of T lymphocytes were significantly increased post-operatively by the administration of NM.

CONCLUSIONS

These results demonstrate that NM controls the enhanced coagulation which occur in patients with extensive hepatic resection. It is also suggested that NM promptly restores the impaired immune responsiveness and decreases the risk of post-operative complications, as well as the risk of recurrence in patients with hepatic tumors.

Impact of splenectomy and immunochemotherapy on survival following gastrectomy for carcinoma: covariate interaction with immunosuppressive acidic protein, a serum marker for the host immune system. Tumor Marker Committee for the Study Group of Immunochemotherapy with PSK for Gastric Cancer

The role of the spleen in tumor immunology is still controversial in that it can either enhance or suppress the antitumor immune response depending on the tumor-bearing host. To clarify this biphasic effect of the spleen, a clinical evaluation of splenectomy in conjunction with immunotherapy and the host immune status was performed in gastric cancer patients. The effect of splenectomy and immunotherapy in 253 gastric cancer patients enrolled in a prospective randomized trial (SIP) was analyzed using the Cox's proportional hazards model in terms of the covariate interaction of the preoperative immunosuppressive acidic protein (IAP) level. In patients with high IAP levels (>580 microg/ml) with predicted negative antitumor immune reactions, splenectomy improved the prognosis. In patients with lower IAP values, conversely, the preservation of the spleen and immunotherapy demonstrated a significant benefit to survival. The spleen was shown to have a biphasic activity in terms of its antitumor immune response depending on the IAP level of the patient. The effect of immunotherapy is significantly influenced by the activity of spleen cells. The preoperative IAP level is therefore considered to be a possible indicator for the effectiveness of splenectomy and immunotherapy in curatively resected gastric cancer patients.

Developing bronchial fistulas as a late complication of extraperiosteal plombage

A 65-year-old male, who underwent extraperiosteal plombage for pulmonary tuberculosis 46 years ago, was referred to our hospital due to relapsing hemosputa and pneumonia. A chest computed tomography scan revealed a bronchial fistula and a fluid collection in one Lucite ball. On May 20, 1996, a right-anterior thoracotomy was performed in a supine position. Five Lucite balls were removed, and the empyema space was tightly filled with an omental pedicle flap. Although the bronchial fistulas were not sutured directly, the air leakage from the drainage tube ceased 12 days later. Two years postoperatively the patient has remained well. Our simple approach of combining an anterior thoracotomy and replacement of an empyema space with an omental pedicle flap in the same posture, without closing bronchial fistulas, would be an easy procedure, and therefore exploitable in patients who have a similar problem.

Blood loss and ICG clearance as best prognostic markers of post-hepatectomy liver failure

BACKGROUND/AIMS

Hepatic failure after hepatic resection is a lethal complication. Various factors affecting the occurrence of hepatic failure were examined.

METHODOLOGY

The subjects were 315 patients who underwent hepatic resection for hepatocellular carcinoma during the 11-year period between 1985 and 1995. Univariate analyses of 14 variables were performed among living and dead patients after hepatic resection. With the significant prognostic variables obtained in the multivariate analysis, the predicted probability of death (PPD) was calculated for each patient.

RESULTS

There were 291 survivors and 24 patients with post-operative liver failure. Among the factors showing statistical or near significance in the univariate analysis, KICG and blood loss were disclosed to be factors independently correlating with survival. PPD was calculated for each patient according to the following equation: PPD = 1/Exp(1.6766 - 0.0004394 x blood loss + 16.69 x KICG) + 1. Assessing the goodness-of-fit model by Hosmer-Lemeshow test indicated the model seemed to fit quite well.

CONCLUSIONS

Minimizing the blood loss during hepatic resection is important to avoid post-operative liver failure. Careful hemostatic procedure is necessary for patients with unexpected massive blood loss during hepatic resection so as to prevent post-operative bleeding.

Circadian rhythm-modulated chemotherapy with high dose 5-fluorouracil against gastrointestinal cancers: evaluation and case report

Circadian variations in chemotherapy toxicity and antitumor effects were investigated in experimental and clinical studies. In the experimental study, Balb/c mice bearing murine colon carcinoma Colon 26 were treated with 4 injections of 5-fluorouracil (5-FU) (80 mg/kg) at 0000 Hours After Light On (HALO), 0600 HALO, 1200 HALO and 1800 HALO. The antitumor effect of treatment at 0000 HALO (early resting phase) group was significantly better with lower toxicity than the 1200 HALO (early activity phase) group, resulting in significantly longer survival (p < 0.05). In the clinical study, the effect of circadian rhythm-modulated 5-FU plus leucovorin therapy was evaluated in an end-stage patient with recurrent gastric carcinoma. After continuous weekly infusion of 5-FU (1000 mg/m2/day x 2) was stopped because of its gastrointestinal toxicity, circadian rhythm-modulated chemotherapy (CRMC) was performed changing the dose of 5-FU to 666 mg/m2/day during the daytime (0500 to 1700) and to 1333 mg/m2/day from evening to night (1700 to 0500). The patient persevered with the 23 CRMC course without any signs of severe side effects and survived for nearly a year, suggesting the potential effect of CRMC in minimizing toxicity and prolonging survival.

Gene structure and quinol oxidase activity of a cytochrome bd-type oxidase from Bacillus stearothermophilus

Gram-positive thermophilic Bacillus species contain cytochrome caa3-type cytochrome c oxidase as their main terminal oxidase in the respiratory chain. We previously identified and purified an alternative oxidase, cytochrome bd-type quinol oxidase, from a mutant of Bacillus stearothermophilus defective in the caa3-type oxidase activity (J. Sakamoto et al., FEMS Microbiol. Lett. 143 (1996) 151-158). Compared with proteobacterial counterparts, B. stearothermophilus cytochrome bd showed lower molecular weights of the two subunits, shorter wavelength of alpha-band absorption maximum due to heme D, and lower quinol oxidase activity. Preincubation with menaquinone-2 enhanced the enzyme activity up to 40 times, suggesting that, besides the catalytic site, there is another quinone-binding site which largely affects the enzyme activity. In order to clarify the molecular basis of the differences of cytochromes bd between B. stearothermophilus and proteobacteria, the genes encoding for the B. stearothermophilus bd was cloned based on its partial peptide sequences. The gene for subunit I (cbdA) encodes 448 amino acid residues with a molecular weight of 50195 Da, which is 14 and 17% shorter than those of Escherichia coli and Azotobacter vinelandii, respectively, and CbdA lacks the C-terminal half of the long hydrophilic loop between the putative transmembrane segments V and VI (Q loop), which has been suggested to include the substrate quinone-binding site for the E. coli enzyme. The gene for subunit II (cbdB) encodes 342 residues with a molecular weight of 38992 Da. Homology search indicated that the B. stearothermophilus cbdAB has the highest sequence similarity to ythAB in B. subtilis genome rather than to cydAB, the first set of cytochrome bd genes identified in the genome. Sequence comparison of cytochromes bd and their homologs from various organisms demonstrates that the proteins can be classified into two subfamilies, a proteobacterial type including E. coli bd and a more widely distributed type including the B. stearothermophilus enzyme, suggesting that the latter type is evolutionarily older.

Phase II trial of 5-fluorouracil and low-dose cisplatin in patients with squamous cell carcinoma of the esophagus

A phase II study was conducted to determine the clinical efficacy and toxicity of 5-fluorouracil (5-FU) and low-dose cisplatin (CDDP) in patients with squamous cell carcinoma of the esophagus. Chemotherapy consisted of 5-FU at a dose of 330 mg/m2 per day, given as a 24-h infusion on days 1-7, and CDDP at a dose of 6 mg/m2 per day, given as a 2-h infusion on days 1-5. Either two or four cycles of chemotherapy were administered to 20 patients with stage III advanced esophageal carcinoma. All 20 patients were then assessed for response and toxicity. An objective response was demonstrated by 11 of the 20 patients, with one complete response (CR) and ten partial responses (PR), bringing the response rate to 55%, with a 95% confidence interval of 27% to 83%. Surgical resection of the tumor was performed in all 20 patients. One patient was found to have a grade 3 histological CR. The median survival of all the patients was 20.5 months, with a range of 4.5 to 48.0 months. Neutropenia and thrombocytopenia developed in five (25%) and two (10%) patients, respectively, and the nonhematologic toxicities were insignificant. The findings of this phase II study indicate that preoperative treatment using 5-FU and low-dose CDDP chemotherapy for patients with advanced esophageal carcinoma appears to achieve a high response rate after short-term administration without affecting the quality of sophisticated lymph node dissection.

Treatment for empyema with bronchopleural fistulas using endobronchial occlusion coils: report of a case

We report herein the case of a woman with bronchopleural fistulas treated with the endobronchial placement of vascular embolization coils. She was referred to our hospital to undergo lavage of a postoperative empyema. She had undergone an air plombage operation for pulmonary tuberculosis 9 years previously. However, bronchopleural fistulas occurred postoperatively and she had to continue the use of a chest drainage tube since then. Lavage of her empyema space with 5kE of OK-432 (Picibanil: Chugai) plus 100 mg minocycline was performed once every 2 weeks for 3 months, and the purulent discharge from the empyema remarkably decreased. Thereafter, the bronchopleural fistulas were occluded endobronchially by the placement of vascular embolization coils. Soon after the procedure, air leakage from the fistulas was stopped and the drainage tube was removed 2 days later. The patient remains well without any additional treatment at 20 months after this treatment. As treatment for empyema with bronchopleural fistulas, it would be worth trying to lavage the empyema space with OK-432 until it is cleaned out and to plug the fistulas by the endobronchial placement of embolization coils, before such radical operations as thoracoplasty and space-filling of the empyema are considered.

Adjuvant therapy with oral fluoropyrimidines as main chemotherapeutic agents after curative resection for colorectal cancer: individual patient data meta-analysis of randomized trials

BACKGROUND

Oral 5-fluorouracil and its prodrugs (tegafur, carmofur) is now being studied for adjuvant chemotherapy of curatively resected colorectal cancers. To evaluate the effect of these oral fluoropyrimidines (o-FPs), an individual patient data (IPD) meta-analysis of randomized clinical trials was performed in Japan as an inter-trialist group study.

METHODS

Data from the three clinical trials in which postoperative adjuvant therapy with o-FPs was compared with surgery alone in patients with colorectal cancer were sought. IPD from a total of 4960 patients with follow-up periods of at least 5 years were analyzed.

RESULTS

The results of the meta-analysis on an 'intention to treat' basis demonstrated a significant benefit of o-FPs in terms of the disease-free survival (DFS) of the total patients [risk ratio (RR) 0.830, 95% confidence interval (CI) 0.742-0.929, P = 0.001]. o-FPs were also demonstrated to be effective for survival in rectal cancer (RR 0.857, 95% CI 0.734-0.999, P = 0.049) and in Dukes'C colorectal cancer (RR 0.828, 95% CI 0.711-0.965, P = 0.016).

CONCLUSION

The results suggest the advantage of long term o-FPs, possibly with the injection of mitomycin C, for prognosis for curatively resected colorectal cancer patients.

Cloning of Bacillus stearothermophilus ctaA and heme A synthesis with the CtaA protein produced in Escherichia coli

The Bacillus stearothermophilus ctaA gene, which is required for heme A synthesis, was found upstream of the ctaBCDEF/caaEABCD gene cluster as in B. subtilis and B. firmus. The deduced protein sequence indicate that CtaA is a 35-kDa intrinsic membrane protein with seven hydrophobic segments. Alignment of CtaA sequences showed conserved residues including histidines that may be involved in heme B binding and substrate binding. Expression of ctaA in E. coli resulted in increased formation of a membrane-bound b-type cytochrome, heme A production, and severe growth inhibition. Furthermore, B. stearothermophilus CtaA produced in E. coli was found to catalyze the conversion of heme O to heme A in vitro.

Ecto-5'-nucleotidase is not required for ischemic preconditioning in rabbit myocardium in situ

This study tested the hypothesis that cardiac ecto-5'-nucleotidase (ecto-5'-NT) activity during ischemic preconditioning (PC) contributes to augmented tolerance against ischemia, thereby reducing infarct size in the rabbit heart in situ. The effects of alpha,beta-methylene-adenosine diphosphate (AOPCP), a selective inhibitor of ecto-5'-NT, on cardiovascular responses to AMP were measured to establish in vivo activities of the enzyme and its inhibitor. Left atrial infusion of AOPCP (0.75 mg . kg-1 . min-1) raised AOPCP plasma levels to 138 microM; under these conditions negative chronotropic and inotropic effects of AMP were blocked, demonstrating essentially full inhibition of ecto-5'-NT in the heart in situ. This AOPCP-blocked heart in situ model was used to examine the proposed contribution of ecto-5'-NT in ischemic PC. Myocardial infarction caused by 30-min ischemia was followed by 3-h reperfusion. Infarct size (IS) was measured and expressed as a percentage of the size of the area at risk (%IS/AR). In untreated controls, %IS/AR was 38.1 +/- 3.8%; PC (5-min ischemia, 5-min reperfusion) markedly reduced %IS/AR to 10.0 +/- 2.0%. Essentially identical IS reductions by PC were observed in AOPCP-blocked animals (%IS/AR = 13.8 +/- 2.2 and 13.3 +/- 1.8% in rabbits receiving AOPCP at 0.75 and 1.50 mg . kg-1 . min-1, respectively); here plasma AOPCP levels were established before and during PC but not during the subsequent prolonged ischemia. As expected, AOPCP also did not affect %IS/AR in non-PC controls (%IS/AR = 35.5 +/- 3.7%). In contrast but as predicted, adenosine-receptor blockade by 8-phenyltheophylline (10 mg/kg iv) substantially attenuated IS reduction by PC in both AOPCP-blocked and control hearts (%IS/AR = 25.2 +/- 4.3 and 21.8 +/- 2.2%, respectively; P < 0.05 vs. PC alone). The results demonstrate that cardiac ecto-5'-NT is not required for ischemic PC against infarction in the rabbit.