Feasibility of Laparoscopic D2 Lymph Node Dissection in Gastric Cancer

PURPOSE: There is still debate regarding the suitability of extension of laparoscopic gastrectomy to advanced gastric cancer. Due to the development of new instruments and techniques, several studies are being conducted to extend the range of laparoscopic gastrectomy. This study was conducted to investigate the appropriateness of laparoscopic D2 lymph node dissection for the treatment of gastric cancer from an oncology perspective. METHODS: A total of 109 patients, 50 of whom had undergone laparoscopy assisted distal gastrectomy (LADG) and 59 patients who underwent open distal gastrectomy (ODG), that were operated on by a single surgeon in the surgery department of Sanggye Paik Hospital from April 2009 to May 2011 were analyzed. All patients underwent D2 lymph node dissection. The clinical characteristics of patients, surgical outcomes and clinicopathologic findings were then compared and analyzed. RESULTS: There was no significant difference in the operation time between the two groups (252.70+/-40.81 vs. 252.20+/-45.22, p=0.698). The day 1 post operation hemoglobin was higher in the LADG group than the ODG group (12.52+/-1.53 vs. 10.54+/-1.57, p=0.011). There were nosignificant differences in resection margin (6.89+/-2.25 vs. 7.20+/-3.42, p=0.254, 4.05+/-2.57 vs. 3.68+/-2.74, p=0.254) or total number of harvested lymph nodes (30.36+/-10.67 vs. 35.44+/-12.56, p=0.508) between groups. CONCLUSION: In stomach cancer surgery, both ODG and LADG can be used to conduct lymph node dissection. Therefore, if the stability and feasibility of LADG is confirmed by prospective studies at multiple centers, laparoscopic gastrectomy may be extended to advanced gastric cancer as well.

Analysis of the Potent Prognostic Factors in Luminal-Type Breast Cancer / 한국유방암학회지

PURPOSE: Luminal-type breast cancer has a good prognosis compared to other types, such as human epidermal growth factor receptor 2 and triple negative types. Luminal-type breast cancer is classified into luminal A and B, according to the proliferation index. We investigated the clinicopathological factors that affect the prognosis of the luminal-type subgroups. METHODS: We reviewed the medical records and the pathologic reports of 159 luminal-type breast cancer patients who were treated between February 2005 and November 2007. We divided luminal-type breast cancer into luminal A and B, according to Ki-67 (cutoff value, 14%) and analyzed the clinicopathologic factors, such as age at diagnosis, intensity score of estrogen receptor and progesterone receptor, histologic grade, and Bcl-2. Moreover, we compared the disease-free survival (DFS) of each group. RESULTS: In the univariate analysis, age (p=0.004), tumor size (p=0.010), lymph node metastasis (p=0.001), and Bcl-2 (p=0.002) were statistically significant factors in luminal-type breast cancer. In the multivariate analysis, lymph node (p=0.049) and Bcl-2 (p=0.034) were significant relevant factors in luminal-type breast cancer. In the subgroup analysis, the increased Bcl-2 (cutoff value, 33%) was related with a longer DFS in the luminal B group (p=0.004). CONCLUSION: In our study, luminal A breast cancer showed a longer DFS than luminal B breast cancer, further, Bcl-2 may be a potent prognostic factor in luminal-type breast cancer.

Comparative Study of a Single-Incision Laparoscopic and a Conventional Laparoscopic Appendectomy for the Treatment of Acute Appendicitis

PURPOSE: For the treatment of acute appendicitis, a conventional laparoscopic appendectomy (LA) has been widely performed. Recently, the use of single incision laparoscopic surgery (SILS) is increasing because it is believed to have advantages over conventional laparoscopic surgery. In this study, we compared SILS and a conventional LA. METHODS: We analyzed the 217 patients who received laparoscopy-assisted appendectomies between August 2010 and April 2012 at Inje University Sanggye Paik Hospital. One hundred-twelve patients underwent SILS, and 105 patients underwent LA. For the two groups, we compared the operation times, postoperative laboratory results, postoperative pain, hospital stay, and postoperative complications. RESULTS: The patients' demographics, including body mass index, were not significantly different between the two groups. There were 6 perforated appendicitis cases in the SILS group and 5 cases in the LA group. The mean operative time in the SILS group was 65.88 +/- 22.74 minutes whereas that in the LA group was 61.70 +/- 22.27 minutes (P = 0.276). There were no significant differences in the mean hospital stays, use of nonsteroidal antiinflammatory drugs, and wound infections between the two groups. CONCLUSION: Postoperative pain, complications and hospital stay showed no statistically significant differences between the SILS and the LA groups. However, our SILS method uses a single trocar and two latex tubes, so cost savings and reduced interference during surgery are expected.

Retrospective analysis of treatment outcomes after postoperative chemoradiotherapy in advanced gastric cancer

PURPOSE: To evaluate retrospectively the survival outcome, patterns of failure, and complications in patients treated with postoperative chemoradiotherapy (CRT) in advanced gastric cancer. MATERIALS AND METHODS: Between January 2000 and December 2006, 80 patients with advanced gastric cancer who received postoperative concurrent CRT were included. Pathological staging was IB-II in 9%, IIIA in 38%, IIIB in 33%, and IV in 21%. Radiotherapy consisted of 45 Gy of radiation. Concurrent chemotherapy consisted of a continuous intravenous infusion of 5-fluorouracil and leucovorin on the first 4 days and last 3 days of radiotherapy. RESULTS: The median follow-up period was 48 months (range, 3 to 83 months). The 5-year overall survival, disease-free survival, and locoregional recurrence-free survivals were 62%, 59%, and 80%, respectively. In the multivariate analysis, significant factors for disease-free survival were T stage (hazard ratio [HR], 0.278; p = 0.038), lymph node dissection extent (HR, 0.201; p = 0.002), and maintenance oral chemotherapy (HR, 2.964; p = 0.004). Locoregional recurrence and distant metastasis occurred in 5 (6%) and 18 (23%) patients, respectively. Mixed failure occurred in 10 (16%) patients. Grade 3 leukopenia and thrombocytopenia were observed in 4 (5%) and one (1%) patient, respectively. Grade 3 nausea and vomiting developed in 8 (10%) patients. Intestinal obstruction developed in one (1%). CONCLUSION: The survival outcome of the postoperative CRT in advanced gastric cancer was similar to those reported previously. Our postoperative CRT regimen seems to be a safe and effective method, reducing locoregional failure without severe treatment toxicity in advanced gastric cancer patients.

Comparison of Doxorubicin Plus Docetaxel Neoadjuvant Chemotherapy with Doxorubicin Plus Vinorelbine in Primary Breast Cancer / 한국유방암학회지

PURPOSE: This study was performed to compare the therapeutic efficacy and toxicity of doxorubicin plus docetaxel neoadjuvant chemotherapy (NC) with doxorubicin plus vinorelbine NC. METHODS: Fifty-three patients underwent 4 cycles of NC consisted of intravenous injection of doxorubicin (50 mg/m2) plus docetaxel (75 mg/m2) administered every 3 weeks (AD), while 49 patients underwent 4 cycles of NC consisted of intravenous injection of doxorubicin (50 mg/m2) and vinorelbine (25 mg/m2) administered every 3 weeks (AN). Response rate and treatment-related toxicities were analyzed by administered chemotherapeutics. Response to NC was also analyzed according to clinicobiological characteristics of the primary tumors. RESULTS: Clinical response was observed in 66% with AN and 81.6% with AD chemotherapy. A complete pathologic response (pCR) was confirmed in 6 patients (11.3%) with AN and in 7 patients (14.3%) with AD after the surgery. Response rate was significantly higher in AD compared with AN (p=0.038), but there was no significant difference between the two group regard to pCR rate. Breast conserving surgery (BCS) was performed in 35.8% of AN group, whereas 20 patients (40.8%) of AD group underwent BCS. The patients with HER2-amplified tumor showed significantly increased response to both types of NC. Pathologic complete response was confirmed in 9 (39.1%) out of 23 HER2-amplified tumors, whereas only 4 (5.1%) of 79 HER2-nonamplified tumors showed pathologic complete response. Febrile neutropenia occurred in 22.6% of total 212 cycles in AN and 38.8% of total 196 cycles in AD. Grade 3/4 neutropenia was observed in 39.6% in AN and 43.9% in AD. Grade 3 mucositis was observed in 26.4% with AN and in 40.8% with AD. CONCLUSION: There was no significant increase of pCR by AD compared with AN. Long-term follow-up results of our study indicate that clinical outcome after NC was significantly associated with initial response to NC regardless of therapeutic regimens.

Comparison of CVF (Cyclophosphamide+Vinorelbine+5-Fluorouracil) and CMF (Cyclophosphamide+Methotrexate+5-Fluorouracil) Adjuvant Chemotherapy in Early Breast Cancer / 한국유방암학회지

PURPOSE: Our study aimed to evaluate the feasibility of adjuvant cyclophosphamide/vinorelbine/5-fluorourail (CVF) chemotherapy as an alternative to cyclophosphamide/methotrexate/5-fluorouracil (CMF) chemotherapy for treating early breast cancer. METHODS: One hundred and forty-nine patients were randomly assigned to CMF or CVF adjuvant chemotherapy for treating their early stage breast cancer between September 2000 and December 2007. The disease-free survival (DFS), the overall survival (OS), and the toxicity profiles of both groups were compared. RESULTS: Sixty-seven patients underwent CMF chemotherapy whereas 82 patients underwent CVF chemotherapy. The DFS and OS were 88 months (95% confidence interval [CI], 76-101 months) and 94 months (95% CI, 83-104 months), respectively for the CMF group, and 97 months (95% CI, 93-101 months), and 101 months (95% CI, 98-104 months), respectively for the CVF group. However, those survival gains of the CVF group were not statistically significant (p-value=0.069 for the DFS and 0.99 for the OS). The CVF group showed a favorable toxicity profile in terms of the grade 3/4 hematologic toxicities as compared to that of the CMF group. CONCLUSION: Clinical outcome of CVF chemotherapy was comparable to CMF with a favorable toxicity profiles. However, it is difficult to conclude the feasibility of CVF regimen because of small number of studied patients.

Lymphovascular Invasion and HER2/neu Amplification as Predictive Factors for Axillary Lymph Node Metastasis in Early Breast Cancer Patients / 한국유방암학회지

PURPOSE: Axillary lymph node metastasis (ALNM) can occur even in breast cancer smaller than 2 cm in size. This study was performed to investigate the clinicopathologic factors that affect node metastasis in T1 breast cancer. METHODS: We reviewed the medical record of 206 T1 breast cancer patients and we divided them into two groups according to the presence or absence of lymph node metastasis. We analyzed the association between ALNM and various clinicopathological predictive factors such as age, tumor size (T1a, T1b, T1c), multiplicity, the histologic grade, the nuclear grade, the presence of lymphovascular invasion (LVI), the estrogen and progesterone receptor status, an HER2/neu expression, the Ki-67 labeling index and the bcl-2 expression. RESULTS: One hundred and thirty-nine were the node negative group (T1N0) and the remaining 67 cases were allotted to the node positive group (T1N1-3). On the univariate analysis, age (p=0.011), LVI (p<0.001), histologic grade (p=0.019), HER2/neu (p<0.005), Ki-67 (p=0.012) and bcl-2 (p=0.026) were the statistically significant predictive factors related to node metastasis. But on the multivariate analysis, LVI (p<0.001) and HER2/neu (p=0.009) were the statistically significant factors related to node metastasis. CONCLUSION: LVI and HER2/neu overexpression were related to the increased incidence of ALNM in T1 breast cancer patients. LVI was the most predictive factor of ALNM.

Expression Profiles of Retinoblastoma Protein and p27Kip1 According to HER2 Amplification Status in Primary Breast Cancer / 한국유방암학회지

PURPOSE: Human epidermal growth factor receptor-2 (HER-2)/neu amplification affects the cell proliferation through the modulation of multiple G1 cell cycle regulators in breast tumor cells. We performed this study to investigate whether retinoblastoma protein (pRB) and p27Kip1 were differently expressed according to the HER2 amplification status in human breast cancer. METHODS: HER2 amplification was assayed by fluorescence in situ hybridization and the expression of cell cycle regulators were assayed by immunohistochemistry on 153 consecutive invasive breast cancers. The proliferative activity of breast cancer was analyzed according to the HER2 amplification and cell cycle protein expression status. RESULTS: HER2 amplification was observed in 39 (25.5%) of 153 breast cancers. In the HER2 amplified breast cancers, the pRB expression was significantly increased (p=0.011) whereas there was no significant relationship between HER2 amplification and p27Kip1 expression. There was an inverse correlation between pRB expression and Ki-67 labeling index in the HER2 amplified breast cancers (p=0.036). In contrast, Ki67 labeling index was significantly decreased as p27Kip1 expression increased in HER2 non-amplified breast cancers (p=0.028). In HER2 non-amplified breast cancers, we could not observe any association between the pRB expression and Ki67 labeling index. CONCLUSION: The proliferation of the breast cancers was associated with pRB expression in HER2 amplified tumors whereas it was associated with p27Kip1 expression in HER2 non-amplified tumors. The results of the current study indicate that the cell proliferative activity of the breast cancer is under different growth signal pathways according to HER2 amplification status.

Analysis of Factors Affecting Local Recurrences after Thyroid Surgery in Low Risk Papillary Thyroid Carcinomas / 대한내분비외과학회지

PURPOSE: This study analyzed factors affecting local recurrences in AGES low risk papillary thyroid carcinomas (PTCs). METHODS: The clinical records of 89 patients who underwent thyroidectomy because of PTC were reviewed. Seventy patients had belonged to low risk PTC according to the AGES classification scheme. The clinical data of these patients concerning disease recurrence was analyzed considering age, gender, operative methods, tumor size, lymph node (LN) metastasis, postoperative radioactive iodine scan (RI scan ¹³¹I), and Synthyroid® intake. RESULTS: Of the 70 patients, 56 were female (80%). Thirtyseven patients underwent total thyroidectomy with central neck LN dissection and 33 patients underwent partial thyroidectomy with ipsilateral central neck LN dissection. Mean tumor size was 2 cm (0.4~6 cm) and 31 patients had LN metastasis. Levels were 2 cm (P=0.030) and partial thyroidectomy (P=0.045). There was no significant association between local recurrence and age, gender, extrathyroidal extension, LN metastasis, RI scan ¹³¹I, or Synthyroid® intake. CONCLUSION: Partial thyroidectomy and tumor size >2 cm are significantly associated with local recurrence in AGES low risk papillary thyroid carcinomas.

Effects of Polyamines on Contractility of Guinea-Pig Gastric Smooth Muscle

This study was designed to investigate the effects of polyamines on mechanical contraction and voltage-dependent calcium current (VDCC) of guinea-pig gastric smooth muscle. Mechanical contraction and calcium channel current (I(Ba)) were recorded by isometric tension recording and whole-cell patch clamp technique. Spermine, spermidine and putrescine inhibited spontaneous contraction of the gastric smooth muscle in a concentration-dependent manner. Spermine (2 mM) reduced high K+ (50 mM)-induced contraction to 16+/-6.4% of the control (n=9), and significantly inhibited I(Ba) in a reversible manner (p<0.05; IC50=0.8 mM). Pre- and post-treatment of tissue with spermine (2-5 mM, n=10) also inhibited acetylcholine (10 micrometer)-induced phasic contraction to 5+/-6.4% of the control. Inhibitory effect of spermine on I(Ba) was observed at a wide range of test potentials of current/voltage (I/V) relationship (p<0.05), and steady-state activation of I(Ba) was shifted to the right by spermine (p<0.05). Spermidine and putrescine (1 mM each) also inhibited I(Ba) to 51+/-5.7% and 81+/-5.3% of the control, respectively. And putrescine (1 mM) inhibited I(Ba) at whole tested potentials (p<0.05) without significant change of kinetics (p<0.05). Finally, 5 mM putrescine also inhibited high K+ -induced contraction to 53+/-7.1% of the control (n=4). These findings suggest that polyamines inhibit contractions of guinea-pig gastric smooth muscle via inhibition of VDCC.

Sodium-activated Potassium Current in Guinea pig Gastric Myocytes

This study was designed to identify and characterize Na+ -activated K+ current (I(K(Na))) in guinea pig gastric myocytes under whole-cell patch clamp. After whole-cell configuration was established under 110 mM intracellular Na+ concentration ([Na+]i) at holding potential of -60 mV, a large inward current was produced by external 60 mM K+([K+] degree). This inward current was not affected by removal of external Ca2+. K+ channel blockers had little effects on the current (p>0.05). Only TEA (5 mM) inhibited steady-state current to 68+/-2.7% of the control (p<0.05). In the presence of K+ channel blocker cocktail (mixture of Ba2+, glibenclamide, 4-AP, apamin, quinidine and TEA), a large inward current was activated. However, the amplitude of the steadystate current produced under [K+]degree (140 mM) was significantly smaller when Na+ in pipette solution was replaced with K+ - and Li+ in the presence of K+ channel blocker cocktail than under 110 mM [Na+]i. In the presence of K+ channel blocker cocktail under low Cl- pipette solution, this current was still activated and seemed K+ -selective, since reversal potentials (E(rev)) of various concentrations of [K+]degree-induced current in current/voltage (I/V) relationship were nearly identical to expected values. R-56865 (10-20 microgram), a blocker of IK(Na), completely and reversibly inhibited this current. The characteristics of the current coincide with those of IK(Na) of other cells. Our results indicate the presence of IK(Na) in guinea pig gastric myocytes.

pH-mediated Regulation of Pacemaker Activity in Cultured Interstitial Cells of Cajal

Interstitial cells of Cajal (ICCs) are pacemakers in gastrointestinal tracts, regulating rhythmicity by activating nonselective cation channels (NSCCs). In the present study, we investigated the general characteristics and pH-mediated regulation of pacemaker activity in cultured interstitial cells of Cajal. Under voltage clamp mode and at the holding potential of -60 mV, the I-V relationships and difference current showed that there was no reversal potential and voltage-independent inward current. Also, when the holding potentials were changed from +20 mV to -80 mV with intervals of 20 mV, there was little difference in inward current. In pacemaker activity, the resting membrane potential (RMP) was depolarized (In pH 5.5, 23+/-1.5 mV depolarized) and the amplitude was decreased by a decrease of the extracellular pH. However, in case of increase of extracellular pH, the RMP was slightly hyperpolarized and the amplitude was decreased a little. The melastatin type transient receptor potential (TRPM) channel 7 has been suggested to be required for intestinal pacemaking activity. TRPM7 produced large outward currents and small inward currents by voltage ramps, ranging from +100 to -100 mV from a holding potential of -60 mV. The inward current of TRPM7 was dramatically increased by a decrease in the extracellular pH. At pH 4.0, the average inward current amplitude measured at -100 mV was increased by about 7 fold, compared with the current amplitude at pH 7.4. Changes in the outward current (measured at +100 mV) were much smaller than those of the inward current. These results indicate that the resting membrane potential of pacemaking activity might be depolarized by external acidic pH through TRPM7 that is required for intestinal pacemaking activity.

Methylene Blue-stained Interstitial Cells are Electrically Active in the Myenteric Board Freshly Prepared from the Murine Small Intestine

Many gastrointestinal muscles show electrical oscillation, so-called "slow wave", originated from interstitial cells of Cajal (ICCs). Thus, a technique to freshly isolate the cells is indispensable to explore the electrophysiological properties of the ICCs. To apply an enzyme solution on the serosal surface for cell isolation, the intestine was inverted and 0.02% trypsin solution and 0.04% collagenase solution were applied to serosal cavity. After the enzyme treatment, mucosal layer was removed and longitudinal muscle layer was gently separated from the rest of tissue. The thin layer was stretched in the recording chamber and mounted on an inverted microscope. Using beta-escine, perforated whole cell patch clamp technique was used. Under a microscope, the tissue showed smooth muscle cells and interstitial cells around the myenteric plexus. Under voltage clamp condition, three types of membrane potential were recorded. One group of interstitial cells, which were positive to methylene blue and CD34, showed spontaneous outward current. These cells had bipolar shape and were considered as fibroblast-like cells because of their peculiar shape and arrangement. Another group, positive to c-kit and methylene blue, showed spontaneous inward current. These cells had more rounded shape and processes and were considered as ICCs. The third, positive to c-kit and had granules containing methylene blue, showed quiet membrane potentials under the voltage-clamp mode. These cells appeared to be resident macrophages. Therefore, in the freshly isolated thin tissue preparation, methylene blue could easily identify three types of cells rather than morphological properties. Using this method, we were able to study electrical properties of fibroblast and residential macrophage as well as myenteric ICCs.

Twice Daily Radiation Therapy Plus Concurrent Chemotherapy for Limited-Stage Small Cell Lung Cancer / 대한방사선종양학회지

PURPOSE: A retrospective study was performed to evaluate the efficiency and feasibility of twice daily radiation therapy plus concurrent chemotherapy for limited-stage small cell lung cancer in terms of treatment response, survival, patterns of failure, and acute toxicities. MATERIALS AND METHODS: Between February 1993 and October 2002, 76 patients of histologically proven limited-stage small cell lung cancer (LS-SCLC) were treated with twice daily radiation therapy and concurrent chemotherapy. Male was in 84% (64/76), and median age was 57 years (range, 32~75 years). Thoracic radiation therapy consisted of 120 or 150 cGy per fraction, twice a day at least 6 hours apart, 5 days a week. Median total dose was 50.4 Gy (range, 45~51 Gy). Concurrent chemotherapy consisted of CAV (cytoxan 1000 mg/m2, adriamycin 40 mg/m2, vincristine 1 mg/m2) alternating with PE (cisplatin 60 mg/m2, etoposide 100 mg/m2) or PE alone, every 3 weeks. The median cycle of chemotherapy was six (range, 1~9 cycle). Prophylactic cranial irradiation (PCI) was recommended to the patients who achieved a complete response (CR). PCI scheme was 25 Gy/ 10 fractions. Median follow up was 18 months (range, 1~136 months). RESULTS: Overall response rate was 86%; complete response in 39 (52%) and partial response in 26 (34%) patients. The median overall survival was 23 months. One, two, and three year overall survival rate was 72%, 50% and 30%, respectively. In univariate analysis, the treatment response was revealed as a significant favorable prognostic factor for survival (p<0.001). Grade 3 or worse acute toxicities were leukopenia in 46 (61%), anemia in 5 (6%), thrombocytopenia in 10 (13%), esophagitis in 5 (6%), and pulmonary toxicity in 2 (2%) patients. Of 73 evaluable patients, 40 (55%) patients subsequently had disease progression. The most frequent first site of distant metastasis was brain. CONCLUSION: Twice daily radiation therapy plus concurrent chemotherapy produced favorable response and survival for LS-SCLC patients with tolerable toxicities. To improve the treatment response, which proved as a significant prognostic factor for survival, there should be further investigations about fractionation scheme, chemotherapy regimens and compatible chemoradiotherapy schedule.

The Effect of External Divalent Cations on Intestinal Pacemaking Activity

Electrical rhythmicity in the gastrointestinal (GI) muscles is generated by pacemaker cells, known as interstitial cells of Cajal (ICC). In the present study, we investigated the effect of external divalent cations on pacemaking activity in cultured ICC from murine small intestine by using whole-cell patch clamp techniques. ICC generated pacemaker currents under a voltage clamp or electrical pacemaker potentials under a current clamp, and showed a mean amplitude of -500+/-50 pA or 30+/-1 mV and the frequency of 18+/-2 cycles/min. Treatments of the cells with external 0 mM Ca2+ stopped pacemaking activity of ICC. In the presence of 2 mM Ca2+, 0 mM external Mg2+ depolarized the resting membrane potential, and there was no change in the frequency of pacemaking activity. However, 10 mM external Mg2+ decreased the frequency of pacemaking activity (6.75+/-1 cycles/min, n=5). We replaced external 2 mM Ca2+ with equimolar Ba2+, Mn2+ and Sr2+, and they all developed inward current in the sequence of Ba2+> Mn2+> Sr2+. Also the frequency of the pacemaking activity was stopped or irregulated. We investigated the effect of 10 mM Ba2+, Mn2+ and Sr2+ on pacemaking activity of ICC in the presence of external 0 mM Mg2+, and found that 10 mM Ba2+ and Mn2+ induced large inward current and stopped the pacemaking activity of ICC (n=5). Interestingly, 10 mM Sr2+ induced small inward current and potentiated the amplitude of pacemaking activity of ICC (n=5). These results indicate that extracellular Ca2+ and Mg2+ are requisite for the pacemaking activity of ICC.

The Role of Mitochondrial ATP-sensitive Potassium Channel on Intestinal Pacemaking Activity

Interstitial cells of Cajal (ICCs) are the pacemaker cells that generate slow waves in the gastrointestinal (GI) tract. In the present study, we investigated the effect of mitochondrial ATP-sensitive potassium (mitoKATP) channel on pacemaking activity in cultured ICCs from murine small intestine by using whole-cell patch clamp techniques. Under current clamp mode, at 10microM glibenclamide, there was no change in pacemaking activity of ICCs. At 30microM glibenclamide, an inhibitor of the ATP sensitive K+ channels, we could find two examples. If pacemaking activity of ICCs was irregulating, pacemaking activity of ICCs was changed into regulating and if in normal conditions, membrane potential amplitude was increased. At 50microM glibenclamide, the resting membrane potential was depolarized. At 3mM 5-HDA, an inhibitor of the mitoKATP channels, inhibited the pacemaking activity of ICCs. Both the amplitude and the frequency were decreased. At 5 mM 5-HDA, both the amplitude and the frequency were completely abolished. Diazoxide, an opener of the mitoKATP channels, was applied to examine its effect on pacemaking activity of ICCs. At 50microM concentration, the pacemaking activity of ICCs was inhibited. Both the amplitude and the frequency were decreased. At 1 mM concentration, both the amplitude and the frequency were completely abolished and the resting membrane potential was shaked. These results indicate that mitoKATP channel has an important role in pacemaking activity of ICCs.

The Effects of DTBNP on Intracellular Ca2+ Signaling in Cultured Bovine Aortic Endothelial Cells

The mechanism underlying oxidant-induced intracellular Ca2+ ([Ca2+]i) increase was studied in cultured bovine aortic endothelial cells (BAECs) using fura-2 AM. In the presence of 2 mM extracellular Ca2+, the application of DTBNP (20microM), a membrane-permeable oxidant, caused an increase in [Ca2+]i, and DTT (2 mM) as a reductant completely reversed the effect of DTBNP. The [Ca2+]i increase induced by DTBNP was also observed in an extracellular Ca2+-free/2 mM EGTA solution, indicating the release of Ca2+ from intracellular store (s). After endoplasmic reticulum was depleted by an IP3-generating agonist, ATP (30microM) or an ER Ca2+ pump inhibitor, thapsigargin (1microM), DTBNP-stressed BAECs showed an increase of [Ca2+]i in Ca2+-free/2 mM EGTA solution. Ratio-differences before and after the application of DTBNP after pretreatment with ATP or thapsigargin were 0.42+/-0.15 and 0.49+/-0.07, respectively (n=7), which are significantly reduced, compared to the control value of 0.72+/-0.07 in a Ca2+-free/2 mM EGTA solution. After the protonophore CCCP (10microM) challenge to release mitochondrial Ca2+, the similar result was obtained. Ratio-difference before and after the application of DTBNP after pretreatment with CCCP was 0.46+/-0.09 (n=7). Simultaneous application of thapsigargin and CCCP completely abolished the DTBNP-induced [Ca2+]i increase. The above results together indicate that the increase of [Ca2+]i by DTBNP resulted from the release of Ca2+ from both endoplasmic reticulum and mitochondria.

Buffering Contribution of Mitochondria to the Ca2+i Increase by Ca2+ Influx through Background Nonselective Cation Channels in Rabbit Aortic Endothelial Cells

To prove the buffering contribution of mitochondria to the increase of intracellular Ca2+ level ([Ca2+]i) via background nonselective cation channel (background NSCC), we examined whether inhibition of mitochondria by protonophore carbonylcyanide m-chlorophenylhydrazone (CCCP) affects endothelial Ca2+ entry and Ca2+ buffering in freshly isolated rabbit aortic endothelial cells (RAECs). The ratio of fluorescence by fura-2 AM (R340/380) was measured in RAECs. Biological state was checked by application of acetylcholine (ACh) and ACh (10microM) increased R340/380 by 1.1+/-0.15 (mean+/-S.E., n=6). When the external Na+ was totally replaced by NMDG+, R340/380 was increased by 1.19+/-0.17 in a reversible manner (n=27). NMDG+-induced [Ca2+]i increase was followed by oscillatory decay after [Ca2+]i reached the peak level. The increase of [Ca2+]i by NMDG+ was completely suppressed by replacement with Cs+. When 1microM CCCP was applied to bath solution, the ratio of [Ca2+]i was increased by 0.4+/-0.06 (n=31). When 1microM CCCP was used for pretreatment before application of NMDG+, oscillatory decay of [Ca2+]i by NMDG+ was significantly inhibited compared to the control (p < 0.05). In addition, NMDG+-induced increase of [Ca2+]i was highly enhanced by pretreatment with 2microM CCCP by 320+/-93.7%, compared to the control (mean+/-S.E., n=12). From these results, it is concluded that mitochondria might have buffering contribution to the [Ca2+]i increase through regulation of the background NSCC in RAECs.

Regulation of L-type Calcium Channel Current by Somatostatin in Guinea-Pig Gastric Myocytes

To study the direct effect of somatostatin (SS) on calcium channel current (IBa) in guinea-pig gastric myocytes, IBa was recorded by using whole-cell patch clamp technique in single smooth muscle cells. Nicardipine (1microM), a L-type Ca2+ channel blocker, inhibited IBa by 98+/-1.9% (n=5), however IBa was decreased in a reversible manner by application of SS. The peak IBa at 0 mV were decreased to 95+/-1.1, 92+/-1.9, 82+/-4.0, 66+/-5.8, 10+/-2.9% at 10-10, 10-9, 10-8, 10-7, 10-5 M of SS, respectively (n=3~6; mean+/-SEM). The steady-state activation and inactivation curves of IBa as a function of membrane potentials were well fitted by a Boltzmann equation. Voltage of half-activation (V0.5) was -12+/-0.5 mV in control and -11+/-1.9 mV in SS treated groups (respectively, n=5). The same values of half-inactivation were -35+/-1.4 mV and -35+/-1.9 mV (respectively, n=5). There was no significant difference in activation and inactivation kinetics of IBa by SS. Inhibitory effect of SS on IBa was significantly reduced by either dialysis of intracellular solution with GDPbetaS, a non-hydrolysable G protein inhibitor, or pretreatment with pertussis toxin (PTX). SS also decreased contraction of guinea-pig gastric antral smooth muscle. In conclusion, SS decreases voltage-dependent L-type calcium channel current (VDCCL) via PTX- sensitive signaling pathways in guinea-pig antral circular myocytes.

Ileal Mesenteric Castleman's Disease

Castleman's disease is a rare disorder characterized by tumorous masses that may develop in the lymph node tissue throughout the body. Most common location is mediastinum, but it can also affect retroperitoneum, neck, pelvis, and/or axilla. It may exceptionally affect extranodal sites like striated muscle, thoracic wall, lungs, skull, larynx, and/or vulva. The presentation is varied and diagnosis is difficult. There are two main types of Castleman's disease: hyaline-vascular type and plasma cell type. The hyaline vascular type accounts for approximately 90% of the cases. Most individuals exhibit no symptoms of this form of the disorder or they may develop non-cancerous growths in the lymph nodes. The plasma cell type is often associated with fever, weight loss, skin rash, early destruction of red blood cells, leading to unusually low levels of circulating red blood cells (hemolytic anemia), and/ or abnormally increased amounts of certain immune factors in the blood (hypergammaglobulinemia). We here report a case of Castleman's disease of ileal mesentery in 30-years old female patient. Abdominal mass, 4.7x3.6 cm in size, was completely removed from ileal mesentery without complication, and confirmed histologically mesenteric Castleman's disease of the mixed type.