Celecoxib-induced increase in cytosolic Ca(2+) levels and apoptosis in HA59T human hepatoma cells.

Celecoxib has been shown to have antitumor effect in previous studies but the mechanisms are unclear. The effect of celecoxib on cytosolic Ca(2+) concentrations ([Ca(2+)]i) and viability in HA59T human hepatoma cells was explored. The Ca(2+)-sensitive fluorescent dye fura-2 was applied to measure [Ca(2+)]i. Celecoxib at concentrations of 10-50 µM induced a [Ca(2+)]i rise in a concentration-dependent manner. The response was reduced by 80% by removing Ca(2+). Celecoxib induced Mn(2+) influx, leading to quenching of fura-2 fluorescence. Celecoxib-evoked Ca(2+) entry was suppressed by nifedipine, econazole, SK&F96365, and protein kinase C modulators. In the absence of extracellular Ca(2+), incubation with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin nearly abolished celecoxib-induced [Ca(2+)]i rise. Incubation with celecoxib abolished thapsigargin-induced [Ca(2+)]i rise. Inhibition of phospholipase C with U73122 abolished celecoxib-induced [Ca(2+)]i rise. At 1-50 µM, celecoxib inhibited cell viability by less than 20%, which was not reversed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N, N, N', N'-tetraacetic acid/acetoxy methyl (BAPTA/AM). Celecoxib (10-50 µM) also induced apoptosis. In sum, in HA59T hepatoma cells, celecoxib induced a [Ca(2+)]i rise by evoking phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via protein kinase C-sensitive store-operated Ca(2+) channels. Celecoxib also caused cell death via apoptosis.

Detection of cytomegalovirus reactivation in cancer patients receiving chemotherapy.

While increasing numbers of cytomegalovirus (CMV)-associated diseases are occurring in patients undergoing conventional chemotherapy, information regarding CMV reactivation is limited. This pilot study was conducted to investigate CMV reactivation induced by chemotherapy. Seven blood samples were collected from each of 15 patients with newly diagnosed malignant disease, at baseline before chemotherapy, and once every month after chemotherapy was commenced. CMV viral loads in leukocytes were determined by real-time PCR. Host responses to changes in viral loads were assessed by assaying CMV-specific IgG titres and tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma levels in each of the blood samples, and by scoring the number of CMV-associated clinical symptoms that developed. All except one patient experienced CMV reactivation during the course of chemotherapy, with the average viral load peaking after the third course of treatment. Titres of CMV-specific IgG increased in line with the increase in viral load. Plasma levels of TNF-alpha and IFN-gamma initially decreased from baseline, and then rose to peak levels at the same time as, or shortly after, the highest viral loads were recorded. Clinical symptoms potentially attributable to CMV infection appeared as the viral load increased. It was concluded that the incidence of CMV reactivation in patients receiving conventional chemotherapy is high. Reactivation is not asymptomatic, but was self-limiting in most of these cases. Increases in plasma TNF-alpha and IFN-gamma occur after reactivation, but not before.

Association analysis of GABA receptor subunit genes on 5q33 with heroin dependence in a Chinese male population.

GABAA receptor subunit genes clustered on 5q33 play a role in the development of alcoholism and methamphetamine use disorder without psychosis. The present study explored the possible contribution of the same subunit genes to the development of heroin dependence. Single nucleotide polymorphisms (SNPs) of the GABAA receptor subunits GABRB2, GABRA6, GABRA1, and GABRG2 were examined in 178 male Han Chinese heroin-dependent and 170 male control subjects. A significant difference in allele frequency for the SNP rs211014 in the GABAAgamma2 receptor subunit gene between cases and controls was identified (P = 0.015). A possible mechanism for the involvement of the GABA receptor subunit genes on 5q33 in the development of heroin dependence is discussed.

Safrole-induced Ca2+ mobilization and cytotoxicity in human PC3 prostate cancer cells.

The effect of the carcinogen safrole on intracellular Ca2+ mobilization and on viability of human PC3 prostate cancer cells was examined. Cytosolic free Ca2+ levels ([Ca2+]i) were measured by using fura-2 as a probe. Safrole at concentrations above 10 microM increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 350 microM. The Ca2+ signal was reduced by more than half after removing extracellular Ca2+ but was unaffected by nifedipine, nicardipine, nimodipine, diltiazem, or verapamil. In Ca2+-free medium, after treatment with 650 microM safrole, 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) failed to release Ca2+. Neither inhibition of phospholipase C with U73122 nor modulation of protein kinase C activity affected safrole-induced Ca2+ release. Overnight incubation with 0.65-65 microM safrole did not affect cell viability, but incubation with 325-625 microM safrole decreased viability. Collectively, the data suggest that in PC3 cells, safrole induced a [Ca2+]i increase by causing Ca2+ release from the endoplasmic reticulum in a phospholipase C- and protein kinase C-independent fashion, and by inducing Ca2+ influx. Safrole can decrease cell viability in a concentration-dependent manner.

Econazole induces increases in free intracellular Ca2+ concentrations in human osteosarcoma cells.

Econazole is an antifungal drug with different in vitro effects. However, econazole's effect on osteoblast-like cells is unknown. In human MG63 osteosarcoma cells, the effect of econazole on intracellular Ca2+ concentrations ([Ca2+]i) was explored by using fura-2. At a concentration of 0.1 microM, econazole started to cause a rise in [Ca2+]i in a concentration-dependent manner. Econazole-induced [Ca2+]i rise was reduced by 74% by removal of extracellular Ca2+. The econazole-induced Ca2+ influx was mediated via a nimodipine-sensitive pathway. In Ca2+ -free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca+ -ATPase, caused a [Ca2+]i rise, after which the increasing effect of econazole on [Ca2+]i was abolished. Pretreatment of cells with econazole to deplete Ca2+ stores totally prevented thapsigargin from releasing Ca2+. U73122, an inhibitor of phospholipase C, abolished histamine (an inositol 1,4,5-trisphosphate-dependent Ca2+ mobilizer)-induced, but not econazole-induced, [Ca2+]i rise. Econazole inhibited 76% of thapsigargin-induced store-operated Ca2+ entry. These findings suggest that in MG63 osteosarcoma cells, econazole increases [Ca2+]i by stimulating Ca2+ influx and Ca2+ release from the endoplasmic reticulum via a phospholipase C-independent manner. In contrast, econazole acts as a potent blocker of store-operated Ca2+ entry.

Risk factors of mortality in perforated peptic ulcer.

OBJECTIVE: To assess the risk factors that influence mortality from perforated peptic ulcer. DESIGN: Retrospective study. SETTING: General hospital, Taiwan. SUBJECTS: 179 patients who had their perforated peptic ulcers operated on and who had minimum follow-up of one year. MAIN OUTCOME MEASURES: Mortality. RESULTS: The overall mortality was 15% (26/179). Of the 26 patients who died, the cause of death was uncontrolled systemic infection in 21 (81%), hypovolaemic shock in 2, and fatal arrhythmia and heart failure in 1 each. 15 of the patients who died of sepsis did not have fulminant abdominal sepsis. Most deaths occurred early after operation, (range 1-96 days). Old age, preoperative shock, and type of operation seemed to be related to these deaths on univariate analysis, but multivariate analysis showed that coexisting medical illness, delayed treatment, and low albumin concentration were independent risk factors for mortality. CONCLUSIONS: To improve the result of treatment of perforated peptic ulcer, the diagnosis and treatment should not be delayed, the associated medical illnesses should be treated, and nutritional support should be given.

Arylamine N-acetyltransferase: a possible promoter in Helicobacter pylori-related gastric carcinogenesis.

BACKGROUND: The hypothesis of an association between peptic ulcer and infection by Helicobacter pylori in the gastroduodenal tract was suggested by Marshall and Warren in 1984. H pylori infection of the stomach is the most frequent infection in the world and exhibits an age-dependent increase. However, only a very small percentage of those infected develop gastric carcinoma, suggesting that H pylori acts as a cofactor in the pathogenesis of gastric carcinoma. N-Acetyltransferase (NAT) is expressed in uroepithelial cells and colon cytosol, while cytosolic acetyltransferase plays a critical role in susceptibility to arylamine-induced bladder and colon cancer. The presence of NAT activity in H pylori has yet to be determined. METHODS: NAT activity in H pylori from patients with peptic ulcer was studied using an acetyl coenzyme A (AcCoA) recycling assay and high-pressure liquid chromatography with p-aminobenzoic acid and aminofluorene substrates. RESULTS: The NAT activities from a number of H pylori samples were found to be 0.68 +/- 0.10 nmol/min/10(10) colony-forming units (CFUs) (intact bacteria); and 0.90 +/- 0.22 nmol/min/mg protein (cytosol) for the acetylation of 2-aminofluorene, and 0.63 +/- 0.06 nmol/min/10(10) CFUs (intact bacteria) and 0.72 +/- 0.24 nmol/min/mg protein (cytosol) for the acetylation of p-aminobenzoic acid. CONCLUSIONS: These studies show that H pylori has NAT activity, from which we speculate that the bioactivation of food-borne heterocyclic aromatic amines into genotoxic and carcinogenic products in the stomach is a possible promoter in the pathogenesis of gastric cancer.

Laparoscopic versus open preperitoneal prosthetic herniorrhaphy for recurrent inguinal hernia.

BACKGROUND: Laparoscopic herniorrhaphy (LH) shares the same repair principle as open preperitoneal prosthetic herniorrhaphy (PPH). Theoretically, the recurrence rate of LH for recurrent inguinal hernia will match the low recurrence rate of PPH (1.2-3%). METHODS: One-hundred forty-five cases of recurrent inguinal hernia were retrospectively studied between 1990 and 1994. Forty-two cases receiving LH were compared to 103 cases receiving PPH. RESULTS: There were no differences in operative time, hospital stay, morbidity rate, satisfaction scale and recurrence rate between the LH group and the PPH group. The LH group showed significantly less postoperative pain and 2 times shorter convalescence (p<0.01). Unsuspected asymptomatic contralateral hernia was found in 4.8% of patients receiving LH. 11.9% of patients had bilateral hernia repairing at the same time in the LH group. CONCLUSIONS: LH is suitable for recurrent inguinal hernia, but further investigation of this technique is required before its wide application.

APACHE II score: a useful tool for risk assessment and an aid to decision-making in emergency operation for bleeding gastric ulcer.

BACKGROUND: Operating for bleeding gastric ulcer remains controversial. Gastric resection bears a higher surgical risk while limited operation may result in more postoperative hemorrhage. There has been little discussion of effective risk assessment of patients. The aim of this study is to define surgical risk by using the APACHE II scoring system, and to determine optimal management. STUDY DESIGN: Records from October 1990 to December 1996 were retrospectively reviewed for patients (n=101) with bleeding gastric ulcer who had undergone emergency operation after failed endoscopic therapy. Mortality rates were examined according to different APACHE II scores, and the surgical risk was defined. From January 1997 to December 1997, 35 consecutive patients were enrolled for prospective study. Partial gastric resection (PGR) was performed for patients with huge ulcers (>2 cm) and for low-risk patients with ulcers at the antrum or angularis, while limited operation (oversewing or excision of bleeding ulcer) was reserved for others. The results were compared with the retrospective study. RESULTS: In the retrospective study, the mortality rates for the group with a score < 15 and > or = 15 were 5% (3 of 63) and 58% (22 of 38), respectively (p < 0.05). In the group with a score < 15, PGR was performed on 27 patients, and one died. For those patients with a score > or = 15, PGR carried a lower mortality than limited operation, although this was not statistically significant (47% vs 65%). Limited operation resulted in an overall rate of 22% postoperative hemorrhage and 12% reoperation rate, in which all patients with a score > or = 15 died. In the prospective study, the mortality rates in those scoring <15 and > or = 15 were 6% and 50%, respectively. This is not significantly different than the retrospective study. However, the rate of postoperative hemorrhage was diminished (5%). CONCLUSIONS: APACHE II score is a useful tool for assessing risk in patients with bleeding gastric ulcer. The mortality is minimal in those with a score <15, and PGR can be performed with low risk. Although high-risk patients have dreadful outcomes, limited operation cannot improve them if postoperative hemorrhage occurs. Decision making in emergency operation for such patients should be based on the ulcer conditions and the patient's hemodynamic status.

Activation of muscarinic K+ channels by extracellular ATP and UTP in rat atrial myocytes.

The effects of extracellular adenine and pyrimidine nucleotides on the acetylcholine-activated K+ channels (KACh) in rat cardiac myocytes were compared and examined by using the patch-clamp technique. In perforated-patch whole-cell recording experiments, extracellular adenosine triphosphate (ATP) reversibly caused an increase in K+ current. 8-Cyclopentyl-1,3-dipropylxanthine (CPX; 1 microM), a potent A1-adenosine-receptor antagonist, only partially antagonized the ATP-induced increase in K+ current, whereas glibenclamide (30 microM) had no effect. In cell-attached mode, adenosine and ATP activated single channels that had nearly identical conductance (29 pS) and open time (1.53 ms). These results suggest that adenosine and ATP can activate the same population of K+ channels. Uridine triphosphate (UTP; 100 microM) also caused an increase in steady-state K+ current. In cell-attached mode, the addition of UTP to the recording pipette solution (not in the bath solution) activated the channel current. The single-channel conductance and open time for UTP-induced channel current were 27 pS and 1.57 ms, respectively. These values were similar to those for the K+ channels activated by adenosine or ATP. The rank order of potency for the activation of KACh channels was adenosine = ATP > UTP. The addition of CPX (1 microM) to the pipette solution attenuated the ATP-induced channel activity by approximately 70% and fully prevented activation by AMPCPP, a less hydrolyzable ATP analog but did not cause any effect on UTP-induced channel activity. In pertussis toxin-treated cardiac myocytes, no any activity of UTP-induced KACh-channel current was observed. Our results demonstrate that extracellular ATP and UTP can directly activate KACh-channel current. This activation also was linked to pertussis toxin-sensitive G protein. The effect of extracellular ATP is mainly caused by the action on binding to A1-adenosine receptor, whereas the effect of extracellular UTP may be mediated possibly by P2u-purinergic (or 5'-nucleotide) receptor.

Correlation of hepatocyte growth factor-induced proliferation and calcium-activated potassium current in human gastric cancer cells.

Hepatocyte growth factor (HGF) has been found to stimulate proliferation and migration of human gastric carcinoma cells. Whether the HGF-induced responses are correlated with the expressed level of HGF receptors or the changes of ionic currents is not clear. The present study investigated the effects of HGF on the proliferation and ionic currents of two human gastric adenocarcinoma cell lines, which were found to express different amounts of HGF receptor. Results showed that HGF induced a dose-dependent growth stimulation and accelerated cell cycle progression in SC-M1 cells. In patch clamp study, HGF treatment induced an outward K+ current and increased the slope conductance at -80 mV from 110+/-15 pS/pF to 207+/-15 pS/pF. The HGF-induced K+ current was abolished when tetraethylammonium chloride was added in bathing solution or a low Ca2+ solution was included in the recording pipette. Furthermore, HGF (10 ng/ml) induced an oscillatory Ca2+-activated K+ current with a lag period of 5+/-3 min in SC-M1 cells. In contrast, HGF did not induce mitogenesis, cell cycle progression and changes in ionic currents in KATO-III cells, although this cell line expressed a higher level of HGF receptors than SC-M1 cells did. These findings provide evidence that the activity of Ca2+-activated K+ channel may be involved in the HGF-induced cell proliferation in human gastric cancer cells, but it did not correlate with the density of HGF receptors.

Effect of hepatocyte growth factor on cell cycle and c-met expression in human gastric cancer cells.

Hepatocyte growth factor (HGF) was found to stimulate the growth and progression of gastric cancer cells through hepatocyte growth factor receptor (HGFR). In the present study, the effects of HGF on the expression of HGFR in relation to cell cycle progression of human gastric cancer cells were investigated by two-parameter flow cytometric analysis. We found that the expression of HGFR in SC-M1 and KATO-III gastric cancer cells was cycle dependent, the level of HGFR increased from GO-G1 to S phase and the highest level of HGFR was found in G2-M phases. The level of HGFR was higher in KATO-III than SC-M1 cells. However, HGF treatment induced a dose-dependent stimulation of growth as well as down-regulation of HGFR in SC-M1 cells but not in KATO-III cells. These results suggest that functional HGFR rather than overexpressed HGFR may be more important for the growth of gastric cancer cells.

Surgical treatment of hepatocellular carcinoma with biliary tumor thrombi.

Treatment is always abandoned in those HCC with jaundice, because it is usually attributed to the underlying liver cirrhosis and extensive tumor. In this series, 7 cases (0.8%) of HCC with jaundice were caused by bile duct invasion and tumor thrombi (BTT). 57% of cases showed Charcot's triad. 57% of BTT were small HCC, significantly higher than the 1.7% of total cases (p<0.05). The growth pattern of BTT was all spreading type, significantly higher than the 42% of total operation cases (p<0.05). The DNA ploidy of BTT was all aneuploid. 57% of BTT had AFP level higher than 400 IU/ml, but it was 27% in total cases. The prognosis is poor in those treated with palliative tube drainage. Aggressive hepatic resection was proved to be safe and achieved the best results in our limited experience. Choledochotomy to remove tumor thrombi is contraindicated because it easily causes tumor seeding. It is advocated to search BTT for resection from the group of HCC with jaundice.

[Laparoscopic cholecystectomy: experience of VGH-Kaohsiung].

One hundred consecutive patients underwent laparoscopic cholecystectomy from May 1991 to February 1992 at Veterans General Hospital--Kaohsiung. Ninety-seven of them presented on an elective basis, including eight patients undergoing endoscopic sphincterotomy with extraction of common bile duct stone before laparoscopic cholecystectomy. The remaining 3 patients were operated during acute cholecystitis episode. Two patients with biliary injuries during laparoscopic cholecystectomy were converted to laparotomy, with a conversion rate of 2%. Intraoperative cystic cholangiogram was done selectively in 7 patients. Major complications occurred in 3 patients, including two biliary injuries and one residual CBD stone. Minor complications of wound infection were found in 7 patients. The overall morbidity rate was 10%. No operative mortality was found. Mean operation time was 112 minutes and mean blood loss was 90 ml. The mean hospital stay (3.1 days) and the mean time of returning to normal activity (14.7 days) were longer than those of Western series, but were shorter than those of open cholecystectomy. Laparoscopic cholecystectomy is a safe and effective procedure that can be performed with minimal risk. However, the importance of accurate preoperative screening and surgical experience should be emphasized for this new procedure. In patients with gall stone plus CBD stone, combined endoscopic sphincterotomy with extraction of CBD stone and laparoscopic cholecystectomy may offer a new therapeutic approach but the long term effect of endoscopic sphincterotomy needs further evaluation.

[The incidence and cause of death following surgery for benign biliary tract disease].

A total of 4056 consecutive patients operated for benign biliary tract disease between January 1983 and June 1990 were reviewed retrospectively. There were 71 in-hospital deaths, representing 1.75% of morality rate. Cholecystectomy was performed in 2275 patients; common bile duct exploration was carried out in 1494, with operative mortality rates of 0.4% and 3.1% respectively. Sepsis was the leading cause of mortality. The second common cause of death was hepatic failure, and respiratory failure the third. Cardiovascular problems accounted for 11.3% of death, which was much lower than reports from western series. Other causes of mortality included hypovolemic shock, anaphylactic shock, epilepsy and hypoglycemia. Of the total 4056 patients, 28.5% underwent emergency surgery. The mortality rate for emergency surgery was 3.6 times higher than for those who underwent elective operations (p less than 0.005) Significantly higher mortality rates were also seen for those aged over 70 years and of male gender. Because the mortality rate of patients who underwent emergency operation due to acute inflammatory or obstructive complications were much higher than that of elective operation group, we suggested early surgical intervention for the symptomatic patients before complications occurred.

External gastrointestinal fistula after the advent of total parental nutrition.

From 1984 to 1988, 173 patients with 190 external gastrointestinal fistulae and given total parenteral nutrition (TPN) were reviewed. The advent of TPN has enabled the patients to be operated in a better condition under a well-planned procedure, and has therefore modified the principle of surgical intervention. However, no significant improvement has been noted in the mortality rate and spontaneous closure rate as compared with the years without TPN. The diseases have changed in pattern to afflict older population and increase the incidence of complicated fistula because of the more sophisticated surgery. It may also have something to do with delayed intervention of the intraabdominal abscess and delayed surgical closure of the fistula due to TPN administration. Early and aggressive treatment against intraabdominal infection, and early closure of the fistulae which fail to close spontaneously with 6-week conservative treatment after subsidence of infection, are advocated.