Melanoma antigen-encoding gene-1 expression in invasive gastric carcinoma: correlation with stage of disease

BACKGROUND

A human melanoma antigen-encoding gene-1, MAGE-1 gene, may be linked to the neoplastic transformation. In the present study, we extended this association with human gastric carcinomas. Specifically, we focused on the relationship between MAGE-1 gene expression and the histologic stage of gastric carcinoma.

METHODS

We used a reverse transcription-polymerase chain reaction assay (RT-PCR) to analyze the expression of the MAGE-1 gene in 38 endoscopic biopsy specimens from gastric carcinomas. We also studied the relationship between the expression of MAGE-1 gene and the genetic expression of several tumor invasion-related factors, including 72 kD type IV collagenase (MMP2), urokinase-type plasminogen activator (uPA), platelet-derived growth factor A (PDGF-A), and vascular endothelial growth factor (VEGF).

RESULTS

Eleven of the 38 tumor samples (28.9%) expressed the MAGE-1 gene. MAGE-1 gene expression was present only in two of the 38 adjacent nontumor samples (5.3%). MAGE-1 gene expression in the 38 tumor samples was significantly correlated with the histological stage of disease (P = 0.0008), especially with the depth of histologically confirmed tumor invasion (t1 vs. t2 or greater, P = 0.00048). The expression of MAGE-1 gene correlated with the expression of MMP2 (P = 0.0064), uPA (P = 0.0390), and PDGF-A (P = 0.00018).

CONCLUSIONS

These data suggest that the MAGE-1 gene may be activated in gastric carcinomas during periods of their development or invasion. In addition, a relationship between MAGE-1 gene expression and expression of invasion-related factors has been demonstrated.

Evaluation of acute ischemic mitral regurgitation following cardiopulmonary bypass assessed by biplane transesophageal echocardiography

The aim of this study was to evaluate pathogenesis and outcome of acute ischemic mitral regurgitation (MR) in patients undergoing coronary artery bypass grafting (CABG) using biplane transesophageal echocardiography (TEE). Biplane TEE was continuously monitored in a total of 96 patients who were scheduled for elective CABG surgery. Of 96 patients, 10 with no MR at stages 1 (after anesthetic induction but before skin incision) and 2 (after cardiopulmonary bypass [CPB] and decannulation) were excluded. In the remaining 86 patients with MR between stages 1 and 2, 45 (group A) had an increase in MR, and 41 (group B) had a decrease in MR. An increase in MR at stage 2 in group A was associated with a significant increase in annular diameter (p < 0.05), and pulmonary capillary wedge pressure (p < 0.01) compared with stage 1. A significant decrease in the left ventricular end-diastolic area (p < 0.01), end-systolic area (p < 0.05) and the mean wall motion abnormality score (WMA score) (p < 0.001) was observed at stage 2 compared with stage 1 in group B. In 16 of 17 patients (94%) with an increased WMA score in group A, a regional wall motion abnormality (RWMA) was detected in the right coronary artery (RCA) and/or left circumflex coronary artery (LCX) areas. In 7 patients in group A, MR increased continuously until stage 3 (after sternal closure) despite treatment. In 2 of these 7 patients, pulmonary venous systolic flow (PVSF) decreased during stage 2 and persisted to stage 3. The post operative course of these 2 patients was complicated with atrial fibrillation (AF). The increase in annular diameter and worsening in RWMA in RCA and/or LCX areas are associated with acute ischemic MR following CPB. The majority of acute ischemic MR cases were resolved by pharmacological intervention. Post operative AF was noted in 2 patients with acute ischemic MR associated with persistently decreased PVSF following CPB despite treatment.

[Effects of bilateral lung volume reduction surgery in a patient with severe pulmonary emphysema]

A 61-year-old man suffering from severe pulmonary emphysema underwent lung volume reduction surgery on both upper lobes. By one year after surgery functional residual capacity had decreased by 2.5 L and FEV1 had increased by a factor of 2.4. Diaphragm excursion, as assessed by dynamic magnetic resonance imaging, had increased and ventilation and pulmonary gas exchange had improved. Performance on a 6-minute-walk test and exercise tolerance measured on a bicycle ergometer improved, and both peak VE and VO2 increased. Before surgery, pulmonary artery pressure Ppa and pulmonary capillary wedge pressure Pewp during exercise were abnormally high, but 6 months after the operation the increases in Ppa and Pcwp during exercise were markedly reduced.

SDS-digested freeze-fracture replica labeling electron microscopy to study the two-dimensional distribution of integral membrane proteins and phospholipids in biomembranes: practical procedure, interpretation and application

Recently, we have developed a quick-freezing/freeze-fracture replica labeling technique, sodium dodecyl sulfate (SDS)-digested freeze-fracture replica labeling (SDS-FRL), to study the two-dimensional distribution of cytochemical labeling on the membrane surface and the relationship of this distribution to images of freeze-fracture replicas created by platinum shadowing. In SDS-FRL, unfixed, quick-frozen cells, after freeze-fracture and platinum/carbon shadowing, are treated with SDS. The detergent dissolves unfractured areas of the cell membranes, with the release of the cytoplasmic contents. The cytoplasmic and exoplasmic membrane surfaces can be then labeled cytochemically. Integral membrane proteins, revealed as intramembrane particles by freeze-fracture replication, which are indistinguishable on a purely morphological basis, can be selectively labeled by SDS-FRL with specific antibody. In addition, this approach can be applied to examine the transmembrane phospholipid distribution in various cell and intracellular membranes. In this review, we describe the practical procedure for SDS-FRL in detail, present its application to labeling of various membrane components, and briefly discuss the possibility of a combination of SDS-FRL with atomic force microscopy.

[Difference of blood cell counts with reference blood cell counters in different makers: Part II]

This is the second report of evaluation on the difference of blood cell counting among different automated blood cell counters in Japan. We tested reference blood cell counters of 6 different companies: Coulter, Sysmex, Bayer-Sankyo, Nihon Kohden, Horiba and Dainabot. Forty ml of whole blood were taken from 3 healthy persons and EDTA-2K anticoagulated blood samples (Sample 1, 2 and 3) were sent to each company to determine blood cell counts with a reference automated counter. As a result, the following items showed more than 10% difference among makers: RBC between Dainabot and Horiba in Sample 3, hematocrit values between Coulter and Dainabot in Sample 2, WBC between Nihon Kohden and each of three makers (Sysmex, Horiba and Dainabot) in all 3 samples and that between Bayer-Sankyo and each of two makers (Sysmex and Horiba) in Sample 3 and platelet count between Dainabot and each of 3 makers (Bayer-Sankyo, Nihon Kohden and Horiba) in all 3 samples. The following items showed difference between 5 and 10%: MCV between Coulter and each of two makers (Bayer-Sankyo and Horiba), WBC between each of two makers (Coulter and Nihon Kohden) and each of other 4 makers, and platelet count between each of two makers (Nihon Kohden and Horiba) and each of 3 makers (Coulter, Sysmex and Bayer-Sankyo). Recently Japanese Committee for Clinical Laboratory Standards proposed minimum clinical allowance of blood cell count as follows: hemoglobin 3%, RBC 4%, MCV 4%, WBC 7% and platelet count 10%. It is suggested that all of the items showing the difference more than above allowance among makers should be improved for clinical use to have good external quality control in blood cell counting by automated instruments.

Studies of bronchial asthma induced by chironomid midges (Diptera) around a hypereutrophic lake in Japan

There have been few reports on hypersensitivity to chironomid midges in bronchial asthmatic patients around the area of hypereutrophic natural lakes, which have been notorious as an environmental hazard due to the massive occurrence of adult chironomids during several periods of the year. Our study investigated IgE antibodies to chironomid midges in bronchial asthmatic patients around the Lake Suwa area in comparison with those of the Matsumoto area (control area). A total of 123 adult patients with bronchial asthma were investigated by measurement of IgE antibodies with extracts of three chironomid midges (Chironomus yoshimatsui, C. plumosus, and Tokunagayusurika akamusi), mite, and silkworm. In addition, in the allergy testing, 12 common inhalant antigens were used. Of 123 adult patients with bronchial asthma, 65 (52.8%) produced positive allergy tests. Thirty-three (50.8%) were positive to mite, 28 (43.1%) to silkworm, 11 (16.9%) to C. yoshimatsui, eight (12.3%) to C. plumosus, and three (4.6%) to T. akamusi. We compared our results with the previous reports. The number of positive tests to silkworm in the Lake Suwa area was higher than in other areas. However, C. plumosus and T. akamusi showed a lower number of positive reactions. We considered the lower positive number of C. plumosus and T. akamusi tests in the Lake Suwa area to be related to the advanced age of patients in this area. The chironomids are an important cause of asthma, together with mite and silkworm, in the Lake Suwa area, but affect old asthmatic patients less than asthmatic children.

Lack of mutations of preproparathyroid hormone gene in three kindreds with familial isolated hypoparathyroidism

The mutations of the preproparathyroid hormone (preproPTH) gene have been reported to cause some cases of familial isolated hypoparathyroidism (FIH). We investigated the preproPTH gene of five affected subjects of three Japanese kindreds with FIH. The mode of inheritance in FIH of two families was thought to be autosomal dominant, and the FIH of the other was probably inherited in an autosomal recessive manner. Exons 1, 2 and 3 of the preproPTH gene and its exon-intron boundaries were analyzed with either polymerase chain reaction and single strand conformational polymorphism, or direct sequencing of the amplified DNA. We did not detect any mutations in the amplified regions of the preproPTH gene, but an A to G transition in intron 1 was identified in all of the affected subjects. Among them, four were heterozygote, and the other was homozygote. This transition was considered to be a polymorphism, which was the same as reported previously. These results indicate that the preproPTH gene abnormalities are not responsible for FIH in these families. Further studies are required to elucidate whether genes coding for other molecules, such as calcium-sensing receptor, are involved in FIH.

Angiogenesis inhibitor TNP-470 suppresses tumorigenesis in rat urinary bladder

PURPOSE

The efficacy of the anti-angiogenic factor TNP-470, an analogue of fumagillin, in controlling the development of bladder tumors was investigated.

MATERIALS AND METHODS

The anti-angiogenic activity of TNP-470 was evaluated in vitro by its capacity to suppress the growth and migration of bovine capillary endothelial cells. To investigate its effect in vivo on the development of tumors, we instilled 0.5 microgram of TNP-470 dissolved in rat urine into heterotopically transplanted rat urinary bladders in which carcinogenesis had been initiated by N-methyl-N-nitrosourea.

RESULTS

In vitro, TNP-470 selectively inhibited the growth and migration of endothelial cells. Instillation of TNP-470 shortly after treatment with carcinogen reduced the tumor incidence significantly (p < 0.05) as compared with that in control animals receiving urine only.

CONCLUSIONS

TNP-470 suppresses the development of bladder tumors when the treatment is started at an early stage of neoplasia. It may be useful in preventing recurrences or new growth of bladder tumors.

Dynamics of connexins, E-cadherin and alpha-catenin on cell membranes during gap junction formation

We examined the dynamics of connexins, E-cadherin and alpha-catenin during gap-junction disassembly and assembly in regeneration hepatocytes by immunofluorescence microscopy, and immunogold-electron microscopy using SDS-digested freeze-replicas. The present findings suggest that during the disappearance of gap junctions most of the gap junction plaques are broken up into smaller aggregates, and then the gap junction proteins may be removed from the cell membrane, but some of the connexons or connexins remain dispersed in the plane of membrane as pure morphologically indistinguishable intramembrane proteins. Double-immunogold electron microscopy using a polyclonal antibody for connexins and a monoclonal antibody for E-cadherin or alpha-catenin revealed co-localization of these molecules at cell-to-cell contact sites during the reappearance of gap junction plaques. This implies that, at least in regenerating hepatocytes, the cadherin-catenin complex-mediated cell-to-cell contact sites act as foci for gap junction formation. In addition, connexin-immunoreactivity was also observed along tight junctional strands, suggesting that the gap junction may also form along the tight junctions.

Analysis of bronchoalveolar lavage fluid in patients with chronic hepatitis C before and after treatment with interferon alpha

BACKGROUND

Previous studies have shown that patients with idiopathic pulmonary fibrosis (IPF) were more likely to be seropositive for hepatitis C virus (HCV) than normal controls, and that patients with chronic hepatitis C treated with interferon alpha (IFN-alpha) sometimes developed pulmonary fibrosis. The possibility that HCV infection and/or treatment with IFN-alpha are involved in the pathogenesis of pulmonary fibrosis or alveolitis was investigated.

METHODS

A prospective non-randomised study was performed in 13 healthy controls and in patients with chronic hepatitis C before (n = 13) and after (n = 10) treatment with IFN-alpha. Bronchoalveolar lavage (BAL) fluid cell counts, ratios and T cell subsets, and the concentrations of interleukin (IL)-1 beta, tumour necrosis factor(TNF)-alpha, and hepatocyte growth factor (HGF) were measured.

RESULTS

Lymphocyte counts in the BAL fluid were significantly increased in both groups of patients (median (range) values: before treatment, 36.8 (1.5-226.0); after treatment, 16.2 (4.5-97.6)) compared with the normal controls (3.3 (0.5-32.3)). In the pretreatment group the activated T cell (HLA-Dr positive) count was also increased (51 (40-74)) compared with that in the normal controls (27 (4-52)), but after treatment it was decreased (40 (0-76)) compared with the pretreatment count. Administration of IFN-alpha did not affect these parameters. IL-1 beta, TNF-alpha, and HGF were not detected.

CONCLUSIONS

These findings suggest that HCV infection is associated with increased counts of lymphocytes and neutrophils in BAL fluid and that treatment with IFN-alpha appears to alter lymphocyte surface markers.

Antihypertensive effect of repeatedly administered YM358, an angiotensin AT1-receptor antagonist, in stroke-prone spontaneously hypertensive rats

YM358 2,7-diethyl-5-[[2'-(1H-tetrazole-5-yl)biphenyl-4-yl]methyl]-5H-pyrazolo[ 1,5-b][1,2,4]-triazole potassium salt), a novel nonpeptide angiotensin AT1-receptor antagonist, was administered daily for 4 weeks to 24-week-old stroke-prone spontaneously hypertensive rats (SHRSP). Its effects on systolic, mean and diastolic arterial pressure (SAP, MAP and DAP), heart rate and locomotor activity were investigated by using radiotelemetry. A clear diurnal variation in blood pressure, heart rate and locomotor activity was observed in synchrony with the light cycle. YM358 at a daily oral dose of 10 or 30 mg/kg produced a reduction of blood pressure in a dose-dependent manner. Although a mild attenuation of the antihypertensive effect of YM358 was observed during the early stage of therapy, YM358 at 30 mg/kg per day produced a significant and consistent decrease in 24-hr MAP and DAP, and it prevented the further development of hypertension. YM358 did not affect either heart rate or locomotor activity or their diurnal variations. After the discontinuation of therapy with YM358, the blood pressure recovered promptly to the control level while there was no sign of a rebound increase in blood pressure. These results suggest that YM358 may be potentially useful for the treatment of hypertension.

Role of apoptosis in duct obstruction-induced pancreatic involution in rats

It has been recognized in mammals that after pancreatic duct obstruction, acinar cells progressively disappear and pancreatic islets are preserved. Previous studies by electron microscopy have suggested the involvement of apoptosis in acinar cell deletion. In the present study, we employed molecular biological methods and investigated whether acinar cell deletion is due to apoptosis. In male Sprague-Dawley rats, pancreatic duct ligation was performed through a left paramedian incision. Pancreatic tissue was studied at each of the following intervals after ligation: 3, 6, 12, 18, and 24 h and 2, 3, 5, and 7 days. DNA fragmentation was determined by in situ labeling of DNA strand breaks on tissue sections [fluorescein-labeled terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling method (TUNEL)] and by electrophoretic detection of the fragments of extracted DNA. Tissue sections were also examined by hematoxylin/eosin staining and immunohistochemical staining of insulin. Pancreatic duct ligation induced acinar cell deletion by day 5. Pancreatic tissue from control rats demonstrated no TUNEL-positive nuclei. In contrast, acinar cells from rats 12 h to 5 days after duct ligation showed TUNEL-positive nuclei. The number of TUNEL-positive nuclei was maximum 2 days after duct ligation. Electrophoresis showed DNA fragmentation after duct ligation. Control rats showed a genomic DNA pattern. Islets were preserved throughout the experimental period in duct-ligated rats and control rats. The results suggest that apoptosis may be the dominant form of acinar cell death in the rat pancreatic duct ligation model.

Activation of prophenoloxidase A1 by an activating enzyme in Drosophila melanogaster

An activating enzyme for prophenoloxidase A1 was isolated from pupae of Drosophila melanogaster, and the activation of purified prophenoloxidase A1 with this enzyme was analyzed. The purification included ammonium sulfate fractionation, DEAE-cellulose, Superdex 75, arginine-Sepharose and hydroxyapatite column chromatography. The prophenoloxidase activating enzyme was determined to be a 28.5-kDa protein consisting of a single polypeptide. The kinetics of the activation reactions was unusual in that the final levels of phenoloxidase activity varied depending on the initial concentrations of the activating enzyme, not those of the prophenoloxidase. The activation was effectively suppressed by the inhibitors of trypsin-type serine protease. The protein has amidolytic activity, and Boc-Val-Pro-Arg-MCA was the best substrate among the synthetic substrates examined. The molecular mass of the activated phenoloxidase was smaller than that of the prophenoloxidase, indicating that a 5-kDa peptide was released from the prophenoloxidase by limited proteolysis with the activating enzyme. The cleavage site of prophenoloxidase A1 was shown to be between Arg and Phe at positions 52 and 53.

Detection of matrix metalloproteinase activity in human pancreatic cancer

Destruction of the basement membrane (BM) is mandatory for tumor spread, and matrix metalloproteinases (MMPs) are known to be implicated in colon cancer invasion and metastasis by digesting type IV collagen, a main component of the BM. The current study analyzed the expression of MMP-2 and MMP-9 in pancreatic cancer tissues. Frozen specimens of pancreatic cancer (n = 10), a liver metastatic nodule from pancreatic cancer (n = 1), and normal pancreas (n = 3) were homogenized and analyzed by zymography. The activated form of MMP-9 (82 kDa) was detected in all of the normal and malignant tissues, while the activated form of MMP-2 (62 kDa) was detected in all of the pancreatic cancers and its metastatic tissue, but not in the normal pancreatic tissues. These results indicate that expression of the activated form of MMP-2 may be specific to pancreatic cancer, while that of MMP-9 may be unrelated to it.

A simple and reliable quick-freezing/freeze-fracturing procedure

We describe a simple method for the quick-freezing/freeze-fracturing of cells in tissues or culture monolayers. Tissue slices or cultured cells were covered with thin copper foil (10-micron-thick), and frozen by smashing them against a liquid helium-cooled copper block. Freeze-fracturing was accomplished by mechanically separating the copper foil from the frozen specimen. The fracture faces were replicated by platinum and carbon. Replicas were processed for conventional electron microscopic observation or cytochemical labeling. This method allows the ultrastructural and cytochemical examination of large areas of fractured membrane without chemical fixation.

Comparison between the Japanese general rules and the TNM system in the regional lymph node classification of carcinoma of the colon

BACKGROUND

Metastasis to regional lymph nodes from carcinoma of the colon is an important prognostic factor. In the tumor, node, metastasis classification, node metastases are classified into four grades based on the number and distribution of metastatic nodes. In the Japanese General Rules for Clinical and Pathological Studies on Cancers of the Colon, Rectum and Anus, node metastases are classified into four grades based solely on the distribution of metastatic nodes.

STUDY DESIGN

Based on the findings of node metastases in 152 patients with carcinoma of the colon obtained by the clearing method, the node classifications by the Japanese General Rules and tumor, node, metastasis classifications were compared.

RESULTS

The case distribution by the Japanese General Rules grading was 38.2 percent in n(-), 30.3 percent in n1(+), 19.7 percent in n2(+), and 11.8 percent in n3(+) disease. In the tumor, node, metastasis classification, the distribution was 22.4 percent in pN1 and pN3 and 17.1 percent in pN2 disease. The five-year survival rate by the Japanese General Rules was 97.9 percent in n(-), 72.6 percent in n1(+), 51.2 percent in n2(+), and 30.0 percent in n3(+) disease, whereas in tumor, node, metastasis classification, this rate was 79.4 percent in pN1, 45.2 percent in pN2, and 44.8 percent in pN3 disease.

CONCLUSIONS

In the classification of regional node metastases from carcinoma of the colon, the Japanese General Rules showed a wider range in distribution and 5-year survival rate compared with the tumor, node, metastasis system.

Flow cytometric platelet enumeration utilizing monoclonal antibody CD42a

We investigated a flow cytometric method with monoclonal antibody CD42a as a potential reference method for platelet enumeration by blood count analysers. Using peripheral blood samples from 25 healthy individuals we obtained significant (P < 0.0001) correlations between the results obtained by a FACScan method and similar cell counters (TOA Medical Electronics, Kobe, Japan): r = 0.960 (FACScan vs SSF), r = 0.958 (FACScan vs SE-9000A,B), r = 0.949 (FACScan vs K-4500A) and r = 0.954 (FACScan vs K-4500B). This flow cytometric method for counting platelets using the monoclonal antibody CD42a can be used to check the calibration of the platelet count by blood cell analysers.

Ethnic differences in gastric sigma-alcohol dehydrogenase activity and ethanol first-pass metabolism

We assessed whether the low sigma-alcohol dehydrogenase (ADH) activity in Japanese (compared with Caucasians) affects the first-pass metabolism of ethanol. ADH isozyme activities were determined in endoscopic biopsies of the gastric corpus from 24 Japanese and 41 Caucasian men by starch gel electrophoresis and by comparing the reduction of m-nitrobenzaldehyde (a preferred substrate of sigma-ADH) with that of acetaldehyde (a preferred substrate of gamma-ADH) and the glutathione-dependent formaldehyde oxidation (a specific reaction of chi-ADH). Alcohol pharmacokinetics was compared in 10 Japanese and 10 Caucasians after administration of ethanol (300 mg/kg of body weight) intravenously or orally, using 5 and 40% oral solutions. Japanese exhibited lower sigma-ADH activity than Caucasians, with no difference in the other gastric isozymes. With 5% ethanol, first-pass metabolism was strikingly lower in Japanese than in Caucasians. Blood alcohol levels were similar because of the high elimination rate in Japanese due to the hepatic beta 2-ADH variant. With 40% ethanol, the first-pass metabolism increased in both groups to comparable levels, suggesting an additional contribution by chi-ADH at high ethanol concentrations. These results indicate that sigma-ADH activity contributes significantly to gastric ethanol oxidation and its lower activity in Japanese is associated with lesser first-pass metabolism.

99Tcm tetrofosmin uptake in mediastinal tumours

We present our experience in visualizing mediastinal tumours using 99Tcm tetrofosmin. Three patients with thymic tumours and two patients with a mediastinal tumour (seminoma and small cell carcinoma) were found to have anterior mediastinal masses on chest radiographs, and subsequently underwent computed tomography and magnetic resonance imaging. In addition, the patients underwent single photon emission computed tomography (SPECT) with 99Tcm tetrofosmin and 201Tl. Intense uptake was seen on early 99Tcm tetrofosmin images in three patients with thymoma, invasive thymoma and mediastinal tumour (small cell carcinoma). In the remaining two patients with thymic carcinoma and mediastinal seminoma, there was intense 99Tcm tetrofosmin uptake on early images which reduced on delayed images. 201Tl uptake was intense on both early and delayed images. These findings suggest that different 99Tcm tetrofosmin uptake in early and delayed imaging may offer new information on these mediastinal tumours.

[Two patients with idiopathic pulmonary fibrosis and monoclonal gammopathy]

A 67-year-old man and a 70-year-old man were admitted to our hospital because of dyspnea and dry coughing. Chest X-ray films showed bilateral reticulonodular shadows in the middle and lower lung fields. Specimens were obtained by open lung biopsies and the findings were compatible with those of usual interstitial pneumonia. Immunoelectrophoresis revealed monoclonal gammopathy in both patients. The levels of interleukin 6 in bronchoalveolar lavage fluid were high. In these two patients, idiopathic pulmonary fibrosis was associated with multiple myeloma and monoclonal gammopathy, and the levels of interleukin-6 in bronchoalveolar lavage fluid were high. These findings may help to elucidate the pathogenesis and development of idiopathic pulmonary fibrosis.

Analysis of regional lymph node metastases from rectal carcinoma by the clearing method. Justification of the use of sigmoid in J-pouch construction after low anterior resection

PURPOSE

It has been reported that functional outcome following low anterior resection of resection of rectal cancer is improved by construction of a colonic J-pouch compared with straight anastomosis. Hence, we tried to justify use of the sigmoid colon in the construction of a J-pouch by the analysis of regional lymph node metastases.

METHODS

A total of 182 patients underwent resection for rectal cancer. Node metastases were examined by the clearing method. According to Japanese General Rules for Clinical and Pathological Studies on Cancer of the Colon, Rectum and Anus (JGR), nodes were classified into the perirectal nodes (PR-N), pericolic nodes (PC-N), central intermediate nodes (C-IM-N), central main nodes (C-M-N), lateral intermediate nodes (L-IM-N), and lateral main nodes (L-M-N).

RESULTS

Metastatic rate (number of patients with node metastases/total number of patients) of PR-N was 57.1 percent. Metastatic rate of C-IM-N was 18.7 percent and that of C-M-N was 7.1 percent. Metastatic rates of L-IM-N and L-M-N were 8.8 and 3.3 percent, respectively, and both were highest in the case of lower rectal cancer. Metastatic rate of PC-N was only 1.1 percent. The number of cases without node metastases (n(-) cases) was 78, that with only PR-N metastases (PR-N cases) was 63, that with intermediate but not main node metastases (IM-N cases) was 29, and that with main node metastases (M-N cases) was 12. Five-year survival rate after curative resection was 88.5 percent for n(-) cases, 70.9 percent for PR-N cases, 65.9 percent for IM-N cases, and 41.7 percent for M-N cases.

CONCLUSIONS

In low anterior resection, high ligation of the inferior mesenteric artery and dissection of C-M-N, C-IM-N and PR-N are necessary, with the addition of the L-IM-N and L-M-N in the case of lower rectal cancer. Resection of sigmoid colon is not required, and therefore, a J-pouch can be constructed using the sigmoid colon. Nodal classification according to the JGR was predictive of case distribution and five-year survival rate.

Effects of structural modulation on biological activity of bombesin analogues with (E)-alkene bond

The specific bombesin receptor antagonist, (E)-alkene bombesin isostere (EABI-1), [D-Phe6,Leu13psi[(E)CH=CH]Leu14]bombesin(6-14) is a potent antagonist in terms of inhibition of bombesin-stimulated amylase release from rat pancreatic acini. This study examined the effects of EABI-1 (L-L diastereomer) and three novel bombesin analogues on amylase release in rat pancreatic acini. EABI-2 is a L-D diastereomer of EABI-1. EABI-3 is an analogue, of which leucine at position 13 of EABI-1 was replaced with valine. EABI-4 is a L-D diastereomer of EABI-3 (L-L). The order of agonist potency was EABI-2>EABI-3>EABI-4. EABI-1 showed no agonist activity at concentrations up to 100nM. On the other hand, all of four analogues had antagonist activity. The order of antagonist potency was EABI-1>EABI-3>EABI-4>EABI-2. EABI-1 was a complete antagonist, EABI-2 and EABI-3 were partial agonists, and EABI-4 had a weak agonist effect. The present study provides a useful information on the future development of peptide analogues for anticancer agents and biological tools for investigating actions of bombesin family peptides.