Gastric Metastasis Mimicking Early Gastric Cancer from Invasive Ductal Carcinoma of the Breast: Case Report and Literature Review.

Backgound and Objectives: Gastric metastasis from invasive ductal breast cancer (BC) is rare. It mainly occurs in patients with lobular BC. The occurrence of multiple metastases is typically observed several years after the primary diagnosis. Endoscopic findings of gastric metastasis of the BC were usually the linitis plastic type. Case presentation: A 72-year-old women who underwent right modified radical mastectomy (MRM) 10 month ago was referred after being diagnosed with early gastric cancer (EGC) during systemic chemotherapy. EGC type I was found at gastric fundus, and pathologic finding showed poorly differentiated adenocarcinoma. Metachronous double primary tumor EGC was considered. Management and Outcome: A laparoscopic total gastrectomy was performed, and postoperative pathology revealed submucosa invasion and two lymph node metastases. A pathologic review that focused on immunohistochemical studies of selected antibodies such as GATA binding protein 3 (GATA3), gross cystic disease fluid protein-15 (GCDFP-15), cytokeratin 7 (CK7) was performed again, comparing previous results. As a result, gastric metastasis from BC was diagnosed. After totally laparoscopic total gastrectomy, palliative first-line chemotherapy with paclitaxel/CDDP was performed. Two months after gastrectomy, she was diagnosed with para-aortic lymph node metastasis and multiple bone metastases. She expired six months after gastrectomy. Conclusions: Gastric metastasis from invasive ductal carcinoma of the breast, which is clinically manifested as EGC, is a very rare condition. If there is a history of BC, careful pathological review will be required.

Vasomotion in human arteries and their regulations based on ion channel regulations: 10 years study.

Vasomotion is the oscillation of vascular tone which gives rise to flow motion of blood into an organ. As is well known, spontaneous contractile organs such as heart, GI, and genitourinary tract produce rhythmic contraction. It imposes or removes pressure on their vessels alternatively for exchange of many substances. It was first described over 150 years ago, however the physiological mechanism and pathophysiological implications are not well understood. This study aimed to elucidate underlying mechanisms and physiological function of vasomotion in human arteries. Conventional contractile force measurement, immunohistochemistry, and Western blot analysis were employed to study human left gastric artery (HLGA) and uterine arteries (HUA). RESULTS: Circular muscle of HLGA and/or HUA produced sustained tonic contraction by high K+ (50 mM) which was blocked by 2 µM nifedipine. Stepwise stretch and high K+ produced nerve-independent spontaneous contraction (vasomotion) (around 45% of tested tissues). Vasomotion was also produced by application of BayK 8644, 5-HT, prostagrandins, oxytocin. It was blocked by nifedipine (2 µM) and blockers of intracellular Ca2+ stores. Inhibitors of Ca2+ -activated Cl- channels (DIDS and/or niflumic acid) and ATP-sensitive K+ (KATP ) channels inhibited vasomotion reversibly. Metabolic inhibition by sodium cyanide (NaCN) and several neuropeptides also regulated vasomotion in KATP channel-sensitive and -insensitive manner. Finally, we identified TMEM16A Ca2+ -activated Cl- channels and subunits of KATP channels (Kir 6.1/6.2 and sulfonylurea receptor 2B [SUR2B]), and c-Kit positivity by Western blot analysis. We conclude that vasomotion is sensitive to TMEM16A Ca2+ -activated Cl- channels and metabolic changes in human gastric and uterine arteries. Vasomotion might play an important role in the regulation of microcirculation dynamics even in pacemaker-related autonomic contractile organs in humans.

Physiological function and molecular composition of ATP-sensitive K+ channels in human gastric smooth muscle.

Gastric motility is controlled by slow waves. In general, the activation of the ATP-sensitive K+ (KATP) channels in the smooth muscle opposes the membrane excitability and produces relaxation. Since metabolic inhibition and/or diabetes mellitus are accompanied by dysfunctions of gastric smooth muscle, we examined the possible roles of KATP channels in human gastric motility. We used human gastric corpus and antrum smooth muscle preparations and recorded the mechanical activities with a conventional contractile measuring system. We also identified the subunits of the KATP channels using Western blot. Pinacidil (10 µM), a KATP channel opener, suppressed contractions to 30% (basal tone to -0.2 g) of the control. The inhibitory effect of pinacidil on contraction was reversed to 59% of the control by glibenclamide (20 µM), a KATP channel blocker. The relaxation by pinacidil was not affected by a pretreatment with L-arginine methyl ester, tetraethylammonium, or 4-aminopyridine. Pinacidil also inhibited the acetylcholine (ACh)-induced tonic and phasic contractions in a glibenclamide-sensitive manner (42% and 6% of the control, respectively). Other KATP channel openers such as diazoxide, cromakalim and nicorandil also inhibited the spontaneous and ACh-induced contractions. Calcitonin gene-related peptide (CGRP), a gastric neuropeptide, induced muscle relaxation by the activation of KATP channels in human gastric smooth muscle. Finally, we have found with Western blot studies, that human gastric smooth muscle expressed KATP channels which were composed of Kir 6.2 and SUR2B subunits.

Dietary vitamin D intake and vitamin D related genetic polymorphisms are not associated with gastric cancer in a hospital-based case-control study in Korea.

There have been few studies on the association between vitamin D levels and gastric cancer in Asian populations, but no studies have been performed on the interactions between vitamin D intake and polymorphisms in the vitamin D pathway. The effects of vitamin D intake, vitamin D related genetic polymorphisms, and their association with the incidence of gastric cancer were investigated in a hospital case-control study, including 715 pairs of newly diagnosed gastric cancer patients and controls matched for age and sex. Correlations between vitamin D intake and plasma vitamin D concentrations were also assessed in a subset of subjects. No statistically significant difference was observed in the dietary intake of vitamin D between the patients and controls, nor were there any evident associations between vitamin D intake and risk of gastric cancer in multivariate analyses. Vitamin D intake significantly correlated with the circulating 25-hydroxyvitamin D levels, but not with the active form of the vitamin, 1,25-dihydroxyvitamin D. There were no statistically significant interactions between vitamin D intake, and VDR or TXNIP polymorphisms. This study suggests that dietary vitamin D intake is not associated with gastric cancer risk, and the genetic polymorphisms of vitamin D-related genes do not modulate the effect of vitamin D with respect to gastric carcinogenesis.

OS 02-06 PHYSIOLOGICAL REGULATION OF VASOMOTION BY INTRACELLULAR ATP-MEDIATED SYSTEM IN HUMAN ARTERY.

OBJECTIVE: Spontaneous oscillation of tone of blood vessel called vasomotion cause vessel to flow blood which is an oscillation of flow into an organ. Microcirculation is sensitive to hypoxic condition and metabolism but mechanism of vasomotion is still poorly understood. DESIGN AND METHOD: Purpose: We studied involvement of metabolism-mediated regulation by intracellular ATP level of vasomotion in human gastric artery. METHODS: Conventional contractile measuring system and Western blot were used. RESULTS: Circular muscle of human gastric artery produced sustained tonic contraction of 1.0 ±â€Š0.19 g by 50 mM high K (n = 36). Pinacidil (10 µM), which is known to activatorof ATP-sensitive K (KATP) channel inhibited vasomotion completely in a reversible manner. Inhibition of vasomotion by activators of KATP channel recovered by glibenclamide. Diazoxide (300 µM), cromakalim (10 µM) nicorandil (10 µM) which is known to activate KATP channel also completely blocked vasomotion in a glibenclamide sensitive manner. Inhibitory effect of these openers of KATP channel on serotonin and norepinephrine-induced contraction were also recoded in a glibenclmide-sensitive manner. In human artery, glucose-free condition which is elated metabolic changes inhibited vasomotion and it was recovered by glibenclamide. Finally, molecular subtypes of KATP channel was defined by Western blot in human artery. CONCLUSIONS: Vasomotion of human gastroepiploic artery was inhibited by activation of specific subtypes of KATP channel and alteration of metabolism.

Additive interactions between PRKAA1 polymorphisms and Helicobacter pylori CagA infection associated with gastric cancer risk in Koreans.

Although several studies reported genetic polymorphisms in protein kinase AMP-activated alpha 1 catalytic subunit (PRKAA1) and their associations with gastric cancer risk, few have evaluated associations between Helicobacter pylori infection and PRKAA1 gene-environment interactions. Here, we evaluated the effects of interactions between H. pylori infection and PRKAA1 polymorphisms on gastric cancer risk in Koreans. In this hospital-based case-control study, PRKAA1 genotypes were analyzed and H. pylori infection and CagA status were examined using a serologic method in 846 pairs of gastric cancer patients and controls matched for age and sex. H. pylori seropositivity was associated with a 1.43-fold [95% confidence interval: 1.12-1.81] increase in the risk of gastric cancer, and CagA low-positive titers during H. pylori infection increased the risk by 1.85-fold (95% confidence interval, 1.38-2.48). Significant positive interaction between the PRKAA1 rs13361707 genotype and H. pylori infection was verified on an additive scale [relative excess risk due to interaction, 0.55; 95% confidence interval, 0.05-1.04; P = 0.030], and the gene-environment interaction between PRKAA1 rs13361707 and CagA status was also statistically significant (relative excess risk due to interaction, 0.50; 95% confidence interval, 0.30-0.70; P < 0.001). Our results indicated that H. pylori infection, CagA status, and PRKAA1 polymorphisms were risk factors for gastric cancer in Koreans, and that the combination of two of these factors rather than their independent effects synergistically increased the risk.

H2 Receptor-Mediated Relaxation of Circular Smooth Muscle in Human Gastric Corpus: the Role of Nitric Oxide (NO).

This study was designed to examine the effects of histamine on gastric motility and its specific receptor in the circular smooth muscle of the human gastric corpus. Histamine mainly produced tonic relaxation in a concentration-dependent and reversible manner, although histamine enhanced contractility in a minor portion of tissues tested. Histamine-induced tonic relaxation was nerve-insensitive because pretreatment with nerve blockers cocktail (NBC) did not inhibit relaxation. Additionally, K(+) channel blockers, such as tetraethylammonium (TEA), apamin (APA), and glibenclamide (Glib), had no effect. However, N(G)-nitro-L-arginine methyl ester (L-NAME) and 1H-(1,2,4)oxadiazolo (4,3-A) quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase (sGC), did inhibit histamine-induced tonic relaxation. In particular, histamine-induced tonic relaxation was converted to tonic contraction by pretreatment with L-NAME. Ranitidine, the H2 receptor blocker, inhibited histamine-induced tonic relaxation. These findings suggest that histamine produced relaxation in circular smooth muscle of human gastric smooth muscle through H2 receptor and NO/sGC pathways.

Risk of gastric cancer is associated with PRKAA1 gene polymorphisms in Koreans.

AIM: To evaluate the association between genetic polymorphisms of the gene encoding AMP-activated protein kinase (PRKAA1) and the risk of gastric cancer. METHODS: The study subjects consisted of 477 age- and sex-matched case-control pairs. Genotyping was performed for 5 tag single nucleotide polymorphisms (SNPs): rs13361707, rs154268, rs3805486, rs6882903, and rs10074991. Associations between gastric cancer and putative risk factors (including the SNPs) were analyzed with multivariate conditional logistic regression models, after adjusting for potential confounding factors. Multiple testing corrections were implemented following methodology for controlling the false discovery rate. Gene-based association tests were performed by using the versatile gene-based association study (VEGAS) method. RESULTS: In the dominant model, SNPs rs13361707 [odds ratio (OR) = 1.51, 95%CI: 1.07-2.11)], rs154268 (OR = 1.65, 95%CI: 1.22-2.22), rs6882903 (OR = 1.48, 95%CI: 1.09-2.00), and rs10074991 (OR = 1.53, 95%CI: 1.09-2.16) were significantly associated with an increased risk of gastric cancer. In the recessive model, SNPs rs154268 (OR = 1.66, 95%CI: 1.22-2.26), rs3805486 (OR = 0.63, 95%CI: 0.46-0.85), and rs10074991 (OR = 1.47, 95%CI: 1.15-1.88) were significant risk or protective factors for gastric cancer. In the codominant model, the ORs of each of the 5 SNPs were statistically significant. All SNPs in the model showed a dose-response relationship between the minor allele frequency and the risk of gastric cancer. Most notably, subjects with a homozygous minor allele in SNP rs10074991 showed 2.15 times the risk of gastric cancer as subjects without a minor allele. The PRKAA1 gene showed a significant gene-based association with gastric cancer in the VEGAS test. CONCLUSION: All 5 tested tag SNPs of the PRKAA1 gene (rs13361707, rs154268, rs3805486, rs6882903, and rs10074991) were significantly associated with gastric cancer.

ITGA1 polymorphisms and haplotypes are associated with gastric cancer risk in a Korean population.

AIM: To evaluate the association between the genetic polymorphisms and haplotypes of the ITGA1 gene and the risk of gastric cancer. METHODS: The study subjects were 477 age- and sex-matched case-control pairs. Genotyping was performed for 15 single nucleotide polymorphisms (SNPs) in ITGA1. The associations between gastric cancer and these SNPs and haplotypes were analyzed with multivariate conditional logistic regression models. Multiple testing corrections were carried out following methodology for controlling the false discovery rate. Gene-based association tests were performed using the versatile gene-based association study (VEGAS) method. RESULTS: In the codominant model, the ORs for SNPs rs2432143 (1.517; 95%CI: 1.144-2.011) and rs2447867 (1.258; 95%CI: 1.051-1.505) were statistically significant. In the dominant model, polymorphisms of rs1862610 and rs2447867 were found to be significant risk factors, with ORs of 1.337 (95%CI: 1.029-1.737) and 1.412 (95%CI: 1.061-1.881), respectively. In the recessive model, only the rs2432143 polymorphism was significant (OR = 1.559, 95%CI: 1.150-2.114). The C-C type of ITGA1 haplotype block 2 was a significant protective factor against gastric cancer in the both codominant model (OR = 0.602, 95%CI: 0.212-0.709, P = 0.021) and the dominant model (OR = 0.653, 95%CI: 0.483-0.884). The ITGA1 gene showed a significant gene-based association with gastric cancer in the VEGAS test. In the dominant model, the A-T type of ITGA1 haplotype block 2 was a significant risk factor (OR = 1.341, 95%CI: 1.034-1.741). SNP rs2447867 might be related to the severity of gastric epithelial injury due to inflammation and, thus, to the risk of developing gastric cancer. CONCLUSION: ITGA1 gene SNPs rs1862610, rs24321 43, and rs2447867 and the ITGA1 haplotype block that includes SNPs rs1862610 and rs2432143 were significantly associated with gastric cancer.

Dietary aflatoxin B1 intake, genetic polymorphisms of CYP1A2, CYP2E1, EPHX1, GSTM1, and GSTT1, and gastric cancer risk in Korean.

PURPOSE: We investigated the effects of aflatoxin B1 (AFB1) intake, genetic polymorphisms of AFB1 metabolic enzymes, and interactions between the polymorphisms and intake of AFB1 with regard to the risk of gastric cancer in Korean. METHODS: The participants in the study included 477 gastric cancer patients and 477 age- and sex-matched control subjects. Direct interviews and a structured questionnaire were used to determine the level of exposure to AFB1, and the GoldenGate assay and multiplex polymerase chain reaction were used for genotypic analyses of the cytochrome P450 1A2 (CYP1A2), cytochrome P450 1E1, epoxide hydrolase 1, and glutathione S-transferase genes. RESULTS: The probable daily intake of AFB1 was significantly higher among gastric cancer patients than among control subjects (cases vs. controls: 1.91 ± 0.87 vs. 1.65 ± 0.72 ng/kg bw/day, p < 0.0001), and increased AFB1 intake was significantly associated with an elevated risk of gastric cancer (odds ratio 1.94; 95 % confidence interval 1.43-2.63). However, genetic polymorphisms of AFB1 metabolic enzymes were not associated with gastric cancer, with the exception of CYP1A2. Moreover, there was no interaction between AFB1 intake and the genotypes of metabolic enzymes that affect gastric cancer risk. CONCLUSIONS: Our results suggest that dietary AFB1 exposure might be associated with a risk of gastric cancer. However, the effect of AFB1 on gastric carcinogenesis may not be modulated by genetic polymorphisms of AFB1 metabolic enzymes.

Mechanism of Relaxation Via TASK-2 Channels in Uterine Circular Muscle of Mouse.

Plasma pH can be altered during pregnancy and at labor. Membrane excitability of smooth muscle including uterine muscle is suppressed by the activation of K(+) channels. Because contractility of uterine muscle is regulated by extracellular pH and humoral factors, K(+) conductance could be connected to factors regulating uterine contractility during pregnancy. Here, we showed that TASK-2 inhibitors such as quinidine, lidocaine, and extracellular acidosis produced contraction in uterine circular muscle of mouse. Furthermore, contractility was significantly increased in pregnant uterine circular muscle than that of non-pregnant muscle. These patterns were not changed even in the presence of tetraetylammonium (TEA) and 4-aminopyridine (4-AP). Finally, TASK-2 inhibitors induced strong myometrial contraction even in the presence of L-methionine, a known inhibitor of stretchactivated channels in myometrium. When compared to non-pregnant myometrium, pregnant myometrium showed increased immunohistochemical expression of TASK-2. Therefore, TASK-2, seems to play a key role during regulation of myometrial contractility in the pregnancy and provides new insight into preventing preterm delivery.

Evaluation of the relationship between dietary factors, CagA-positive Helicobacter pylori infection, and RUNX3 promoter hypermethylation in gastric cancer tissue.

AIM: To evaluate the relationship among Helicobacter pylori (H. pylori) infection, CagA status, and dietary factors with RUNX3 promoter hypermethylation. METHODS: Gastric cancer tissue samples were collected from 184 South Korean patients. All patients were interviewed following a semi-quantitative food frequency questionnaire. The average frequencies of intake and portion sizes of 89 common food items were documented, and total intakes of calories, nutrients, vitamins, and minerals were calculated for each subject. DNA was extracted from gastric cancer tissue samples, and amplification of the HSP60 gene was performed to detect H. pylori infection. Nested polymerase chain reaction (PCR) was used to detect the presence of the CagA gene. RUNX3 gene expression was measured by reverse transcription-PCR, and RUNX3 methylation status was evaluated by methylation-specific PCR. The odds ratios (ORs) and 95%CI associated with RUNX3 promoter hypermethylation status were estimated for each of the food groups, lifestyle factors, and the interaction between dietary and lifestyle factors with CagA status of H. pylori infection. RESULTS: Overall, 164 patients (89.1%) were positive for H. pylori DNA, with the CagA gene detected in 59 (36%) of these H. pylori-positive samples. In all, 106 (57.6%) patients with gastric cancer demonstrated CpG island hypermethylation at the RUNX3 promoter. RUNX3 expression was undetectable in 52 (43.7%) of the 119 gastric cancer tissues sampled. A high consumption of eggs may increase the risk of RUNX3 methylation in gastric cancer patients, having a mean OR of 2.15 (range, 1.14-4.08). A significantly increased OR of 4.28 (range, 1.19-15.49) was observed with a high consumption of nuts in patients with CagA-positive H. pylori infection. High intakes of carbohydrate, vitamin B1, and vitamin E may decrease the risk of RUNX3 methylation in gastric cancer tissue, particularly in CagA- or H. pylori-negative infection, with OR of 0.41 (0.19-0.90), 0.42 (0.20-0.89), and 0.29 (0.13-0.62), respectively. A high consumption of fruits may protect against RUNX3 methylation. CONCLUSION: These results suggest that the CagA status of H. pylori infection may be a modifier of dietary effects on RUNX3 methylation in gastric cancer tissue.

Interstitial cells of Cajal (ICC)-like-c-Kit positive cells are involved in gastritis and carcinogenesis in human stomach.

This study was executed to prove the existence of c-Kit-positive interstitial cells of Cajal (ICC)-like cells [c-Kit (+) ICC-like cells] and their possible role associated with gastric inflammation and/or carcinogenesis in human gastric mucosa. c-Kit (+) ICC-like cells were observed throughout all the layers of the gastric fundus along the greater curvature. Dense fusiform cell bodies with many processes were found in each layer. We also studied the c-Kit-positive immunoreactivity distribution pattern in the mucosa. c-Kit (+) cells were found mainly around the epithelial repair zone of the normal gastric fundus/corpus and of the fundus/corpus with non-metaplastic chronic gastritis. Notably, they were found attached to the epithelia of the repair zone in non-metaplastic chronic gastritis. In chronic gastritis with intestinal metaplasia, they were found scattered everywhere in the stroma of the gastric mucosa and did not attach to the metaplastic epithelium. We found c-Kit (+) ICC-like cells in human mucosa. They were present mainly in the stroma around the repair zone of the glands in chronic gastritis as well as in normal mucosa, whereas they seemed to redistribute over the whole mucosa in gastritis with intestinal metaplasia. These cells around the repair zone were found to be tightly attached to epithelial cells, but not to metaplastic epithelial cells. Thus, c-Kit (+) ICC-like cells appear to have a role in the epithelial recovery process and may be associated with carcinogenesis of human gastric mucosa.

Regional Distribution of Interstitial Cells of Cajal (ICC) in Human Stomach.

We elucidated the distribution of interstitial cells of Cajal (ICC) in human stomach, using cryosection and c-Kit immunohistochemistry to identify c-Kit positive ICC. Before c-Kit staining, we routinely used hematoxylin and eosin (HE) staining to identify every structure of human stomach, from mucosa to longitudinal muscle. HE staining revealed that the fundus greater curvature (GC) had prominent oblique muscle layer, and c-Kit immunostaining c-Kit positive ICC cells were found to have typical morphology of dense fusiform cell body with multiple processes protruding from the central cell body. In particular, we could observe dense processes and ramifications of ICC in myenteric area and longitudinal muscle layer of corpus GC. Interestingly, c-Kit positive ICC-like cells which had morphology very similar to ICC were found in gastric mucosa. We could not find any significant difference in the distribution of ICC between fundus and corpus, except for submucosa where the density of ICC was much higher in gastric fundus than corpus. Furthermore, there was no significant difference in the density of ICC between each area of fundus and corpus, except for muscularis mucosa. Finally, we also found similar distribution of ICC in normal and cancerous tissue obtained from a patient who underwent pancreotomy and gastrectomy. In conclusion, ICC was found ubiquitously in human stomach and the density of ICC was significantly lower in the muscularis mucosa of both fundus/corpus and higher in the submucosa of gastric fundus than corpus.

Effects of dietary factors and the NAT2 acetylator status on gastric cancer in Koreans.

Environmental dietary carcinogens and genetic polymorphisms in metabolic enzymes have been reported to be the risk factors for gastric cancer. This study was undertaken to investigate the effects of the diet, the N-acetyltransferase (NAT) 2 acetylation status and their interaction on gastric cancer risk. The study population consisted of 471 gastric cancer patients and 471 age- and sex-matched control subjects. NAT2 genotypes were identified using single-nucleotide primer extension reaction methods. Thirty-one alleles related to 12 polymorphism sites were assayed in this study. Significantly increased odds ratios were observed in former smokers (OR = 2.39, 95% CI = 1.57-3.62), heavy drinkers (OR = 1.28, 95% CI = 1.06-1.55) and individuals who eat well-done meat (OR = 1.24, 95% CI = 1.09-1.41). The odds ratios (95% CI) for high intake of kimchi, stews and soybean paste were 3.27 (2.44-4.37), 1.96 (1.50-2.58) and 1.63 (1.24-2.14), respectively. The NAT2 genotype alone was not associated with gastric cancer risk. A significant gene-environment interaction was observed between environmental carcinogens and NAT2 genotypes. The odds ratios for kimchi, stews and soybean paste were higher in slow/intermediate acetylators than in rapid acetylators. The odds ratios for slow/intermediate acetylators were 2.28 (95% CI: 1.29-4.04) for light smokers and 3.42 (95% CI: 2.06-5.68) for well-done meat intake. The NAT2 acetylator genotype may be an important modifier of the effects of environmental factors on gastric cancer risk.

Relaxation patterns of human gastric corporal smooth muscle by cyclic nucleotides producing agents.

To elucidate the mechanism of cyclic nucleotides, such as adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5' -cyclic monophosphate (cGMP), in the regulation of human gastric motility, we examined the effects of forskolin (FSK), isoproterenol (ISO) and sodium nitroprusside (SNP) on the spontaneous, high K(+) and acetylcholine (ACh)-induced contractions of corporal circular smooth muscle in human stomach. Gastric circular smooth muscle showed regular spontaneous contraction, and FSK, ISO and SNP inhibited its phasic contraction and basal tone in a concentration-dependent manner. High K(+) (50 mM) produced sustained tonic contraction, and ACh (10 microM) produced initial transient contraction followed by later sustained tonic contraction with superimposed phasic contractions. FSK, ISO and SNP inhibited high K(+)-induced tonic contraction and also ACh-induced phasic and tonic contraction in a reversible manner. Nifedipine (1 microM), inhibitor of voltage-dependent L-type calcium current (VDCC(L)), almost abolished ACh-induced phasic contractions. These findings suggest that FSK, ISO and SNP, which are known cyclic nucleotide stimulators, inhibit smooth muscle contraction in human stomach partly via inhibition of VDCC(L).

Optimal extent of lymph node dissection for T1 gastric cancer, with special reference to the distribution of micrometastasis, and accuracy of preoperative diagnosis for wall invasion.

BACKGROUND/AIMS: Preoperative diagnosis for wall invasion and lymph node metastasis is sometimes difficult in T1 gastric cancer. Optimum dissection extent of lymph nodes for T1 gastric cancer was studied from the aspect of subclassification of wall invasion and lymph node metastasis including micrometastasis. METHODOLOGY: 184 patients with cT1 or pT1 gastric cancer were studied. The grade of clinical wall invasion (cT) and clinical lymph node status (cN) were diagnosed by endoscopy and computed tomography or intraoperative findings. Lymph node metastasis (pN) was studied by hematoxylin and eosin staining and immunohistochemistry (IHC). RESULTS: In 79 cM tumors, 60 (75.9%) were diagnosed as pM. In 88 cSM tumors, 42 (47.7%) were diagnosed as pSM. In 94 pM gastric cancers, micrometastases were found in two patients (2.1%) and in N1 stations. Two (1.9%) of 70 pSM cancers had micrometastasis in No. 7, 8a and 12a stations. Lymph node metastasis (pN) correlated significantly with the depth of tumor invasion, lymphatic invasion and venous invasion. Regarding the pN2 stations, one (1.1%) of 94 pM tumors had lymph node metastasis in No.7 station, and 9 (12.9%) of 70 pSM tumors had nodal involvement in No.7, 8a, 11p, 12a and 14v stations. All eight pN+/cM tumors were diagnosed as nN0 and four (1.4%) of 23 pN+/cSM tumors were correctly diagnosed as pN+. In contrast, 8 (9.9%) of 81 cN0/cM tumors and 19 (24.1%) of 79 cN0/cSM tumors had histological lymph node metastasis (pN+). CONCLUSIONS: Accuracy of the clinical diagnosis of lymph node metastasis is very low. Accordingly, prophylactic lymph node dissection is recommended even for cT1 and cN0 tumors. For cN0/cM cancer, D1+No.7 is recommended. D1+No.7, 8a, 9, 11p is recommended for cSM cancer, located in U or M region and additional dissection of No. 14v is recommended for cSM cancer located in L region.

Voltage-dependent Ca Current Identified in Freshly Isolated Interstitial Cells of Cajal (ICC) of Guinea-pig Stomach.

The properties of voltage dependent Ca(2+) current (VDCC) were investigated in interstitial cells of Cajal (ICC) distributed in the myenteric layer (ICC-MY) of guinea-pig antrum. In tissue, ICC-MY showed c-Kit positive reactions and produced driving potentials with the amplitude and frequency of about 62 mV and 2 times min(-1), respectively, in the presence of 1 microM nifedipine. Single ICC-MY isolated by enzyme treatment also showed c-Kit immunohistochemical reactivity. These cells were also identified by generation of spontaneous inward current under K(+) -rich pipette solution. The voltage clamp experiments revealed the amplitude of - 329 pA inward current at irregular frequency. With Cs(+)-rich pipette solution at V(h)=-80 mV, ICC-MY produced voltage-dependent inward currents (VDIC), and nifedipine (1 microM) blocked VDIC. Therefore, we successfully isolated c-Kit positive single ICC from guinea-pig stomach, and found that ICC-MY potently produced dihydropiridine sensitive L-type voltage-dependent Ca(2+) currents (VDCC(L)).

Evaluation of lymphatic invasion in primary gastric cancer by a new monoclonal antibody, D2-40.

Lymphatic invasion is known as an independent predictor of lymph node metastasis in gastric cancer. However, the diagnosis of lymphatic invasion is sometimes difficult by hematoxylin-eosin (H&E) staining. Immunostaining using D2-40 was performed to study the distribution of lymphatic vessel and lymphatic invasion in a series of 78 primary gastric cancers. D2-40 showed specific staining for the lymphatic vessels, but not for blood vessels. The lymphatic invasion was most frequently found in the upper half of submucosal layer. Positive rate of lymphatic invasion by H&E staining was 27% (21/78), and that by D2-40 was 44% (34/78). Lymphatic invasion on H&E staining was diagnosed as false negative in 17 (21.8%) of 78 primary gastric cancers and false positive in 4 (5.1%) of 78 primary gastric cancers. Sensitivity for lymph node metastasis by the lymphatic invasion diagnosed by D2-40 was significantly higher (89%, 24/27) than by H&E staining (41%, 11/27). These results suggest that the diagnosis of lymphatic invasion by D2-40 is more sensitive than H&E staining. Sensitivity for the prediction of lymph node metastasis from the lymphatic invasion status in primary tumor by D2-40 was significantly higher than by H&E staining. Based on our results, we recommend the use of D2-40 immunoreactions for the routine evaluation of lymphatic invasion in gastric cancer.