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.

Effect of phenethyl isothiocyanate on Ca2+ movement and viability in MDCK canine renal tubular cells.

The effect of the natural compound phenethyl isothiocyanate (PEITC) on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) and viability in MDCK renal cells is unknown. This study explored whether PEITC changed [Ca(2+)](i) in MDCK cells using the Ca(2+)-sensitive fluorescent dye fura-2. PEITC at 200-700 µM increased [Ca(2+)](i) in a concentration-dependent manner. The signal was reduced by removing extracellular Ca(2+). PEITC-induced Ca(2+) influx was inhibited by nifedipine, econazole, SK&F 96365 and protein kinase C modulators. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (TG) or 2,5-di-tert-butylhydroquinone (BHQ) inhibited PEITC-induced rise in [Ca(2+)](i). Incubation with PEITC also inhibited TG or BHQ-induced rise in [Ca(2+)](i). Inhibition of phospholipase C with U73122 abolished PEITC-induced rise in [Ca(2+)](i). At 15-75 µM, PEITC decreased viability. The cytotoxic effect of PEITC was enhanced by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxymethyl ester. Annexin V-FITC data suggest that 20 and 50 µM PEITC induced apoptosis. At 10 and 15 µM, PEITC did not increase reactive oxygen species (ROS) production. Together, in renal tubular cells, PEITC-induced rise in [Ca(2+)](i) by inducing phospholipase C-dependent Ca(2+) release from endoplasmic reticulum and Ca(2+) entry via store-operated Ca(2+) channels. PEITC induced apoptosis in a concentration-dependent, ROS/Ca(2+)-independent manner.

Melittin-induced [Ca2+]i increases and subsequent death in canine renal tubular cells.

The effect of melittin on cytosolic free Ca(2+) concentration ([Ca(2+)](i)) and viability is largely unknown. This study examined whether melittin alters Ca(2+) levels and causes Ca(2+)-dependent cell death in Madin-Darby canine kidney (MDCK) cells. [Ca(2+)](i) and cell death were measured using the fluorescent dyes fura-2 and WST-1 respectively. Melittin at concentrations above 0.5 microM increased [Ca(2+)](i) in a concentration-dependent manner. The Ca(2+) signal was reduced by 75% by removing extracellular Ca(2+). The melittin-induced Ca(2+) influx was also implicated by melittin-caused Mn(2+) influx. After pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor), melittin-induced Ca(2+) release was inhibited; and conversely, melittin pretreatment abolished thapsigargin-induced Ca(2+) release. At concentrations of 0.5-20 microM, melittin killed cells in a concentration-dependent manner. The cytotoxic effect of 0.5 microM melittin was nearly completely reversed by prechelating cytosolic Ca(2+) with BAPTA. Melittin at 0.5-2 microM caused apoptosis as assessed by flow cytometry of propidium iodide staining. Collectively, in MDCK cells, melittin induced a [Ca(2+)](i) rise by causing Ca(2+) release from endoplasmic reticulum and Ca(2+) influx from extracellular space. Furthermore, melittin can cause Ca(2+)-dependent cytotoxicity in a concentration-dependent manner.

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.

Psychosocial effects on caregivers for children on chronic peritoneal dialysis.

The study was designed to explore the psychosocial effects on caretakers of children in Taiwan on chronic peritoneal dialysis (CPD). This is a case-control study, performed with subjects drawn from eight medical centers. The study group consisted of caretakers of 32 children with renal failure being treated with CPD. For comparison, a control group of caretakers of 64 healthy children as well as the regional Taiwanese studies were used. Two instruments were used to explore the presence of probable depression and quality of life (QOL) of the caretakers: the Taiwanese Depression Questionnaire, and the World Health Organization QOL BRIEF-Taiwan Version. In the study group, only 25% of caregivers had full-time jobs, and 66% of families had an annual income of less than US dollar 15,000. Of the 32 families in the study group, 16% had only a single parent. The prevalence of probable depression was significantly more common in the study group compared with control and referent group (28% vs 5% and 9.44%; P = 0.001). QOL scores in four domains were also significantly lower in the study group. In conclusion, even with the advances of peritoneal dialysis techniques, caring for children on CPD in Taiwan has significant adverse psychosocial effects on the primary caregivers. Attention should be paid to the psycho-social status of the caregivers.

Effect of riluzole on Ca2+ movement and cytotoxicity in Madin-Darby canine kidney cells.

Riluzole is a drug used in the treatment of amyotrophic lateral sclerosis; however, its in vitro action is unclear. In this study, the effect of riluzole on intracellular Ca2+ concentration ([Ca2+]i) in Madin-Darby canine kidney (MDCK) cells was investigated using the Ca2+ -sensitive fluorescent dye, fura-2. Riluzole (100-500 microM) caused a rapid and sustained increase of [Ca2+]i in a concentration-dependent manner (EC50 = 150 microM). Some 40 and 50% of this [Ca2+]i increase was prevented by the removal of extracellular Ca2+ and the addition of La3+, respectively, but was unchanged by dihydropyridines, verapamil and diltiazem. In Ca2+ -free medium, thapsigargin - an inhibitor of the endoplasmic reticulum (ER) Caz+ -ATPase--caused a monophasic [Ca2+]i increase, after which the increasing effect of riluzole on [Ca2+]i was attenuated by 70%; in addition, pre-treatment with riluzole abolished thapsigargin-induced [Ca2+]i increases. U73122, an inhibitor of phospholipase C (PLC), abolished ATP (but not riluzole)-induced [Ca2+]i increases. At concentrations of 250 and 500 microM, riluzole killed 40 and 95% cells, respectively. The cytotoxic effect of riluzole (250 microM) was unaltered by pre-chelating cytosolic Ca2+ with BAPTA. Collectively, in MDCK cells, riluzole rapidly increased [Ca2+]i by stimulating extracellular Ca2+ influx via an La3+ -sensitive pathway and intracellular Ca2+ release from the ER via, as yet, unidentified mechanisms. Furthermore, riluzole caused Ca2+ -unrelated cytotoxicity in a concentration-dependent manner.

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.

Effect of celecoxib on Ca2+ fluxes and proliferation in MDCK renal tubular cells.

The effect of celecoxib on renal tubular cells is largely unexplored. In Madin Darby canine kidney (MDCK) cells, the effect of celecoxib on intracellular CaCa2+ concentration ([Ca2+]i) and proliferation was examined by using the Ca(2 +)-sensitive fluorescent dye fura-2 and the viability detecting fluorescent dye tetrazolium, respectively. Celecoxib (> or =1 micro M) caused an increase of [CaCa2+]i in a concentration-dependent manner. Celecoxib-induced [CaCa2+]i increase was partly reduced by removal of extracellular CaCa2+. Celecoxib-induced CaCa2+ influx was independently suggested by MnCa2+ influx-induced fura-2 fluorescence quench. In Ca(2 +)-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca(2 +)-ATPase, caused a monophasic [CaCa2+]i increase, after which celecoxib only induced a tiny [CaCa2+]i increase; conversely, pretreatment with celecoxib completely inhibited thapsigargin-induced [CaCa2+]i increases. U73122, an inhibitor of phospholipase C, abolished ATP (but not celecoxib)-induced [CaCa2+]i increases. Overnight incubation with 1 or 10 micro M celecoxib decreased cell viability by 80% and 100%, respectively. These data indicate that celecoxib evokes a [CaCa2+]i increase in renal tubular cells by stimulating both extracellular CaCa2+ influx and intracellular CaCa2+ release and is highly toxic to renal tubular cells in vitro.

The prevalence of psychiatric morbidity and its associated factors in general health care in Taiwan.

BACKGROUND: This paper reports the prevalence, disability, sociodemographic and clinical association of psychiatric morbidity among attenders in general health care in Taiwan where, as in the rest of non-Western countries, few studies have been carried out. METHODS: A cross-sectional survey with a two-phase design was carried out at out-patient clinics of three health stations and a general hospital. RESULTS: A total of 990 patients completed the brief screen in the first phase, 486 of whom completed the independent assessment in the second phase. The proportion of screening positives was 46.0% and the weighted prevalence of definite psychiatric disorder was 38.2%. Common mental disorders were associated with female gender and unemployment. Housewives, students and patients with higher educational attainment were at lower risk of having alcohol use disorders. Patients with common mental disorders were more likely to present with psychological complaints, to attribute their illness to psychosocial causes and to perceive their mental and physical health as poor. Psychiatric morbidity was associated with excess life events. Common mental disorders, particularly depressive disorders, were significantly associated with self-reported disability. CONCLUSIONS: Psychiatric morbidity is a major health problem in general health care in Taiwan. Physicians should be aware of these health problems.

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.

Alcohol use disorders among the Yami aborigines in Taiwan. An inter-ethnic comparison.

BACKGROUND: Alcohol use disorders (AUDs) among the Yami aborigines in Taiwan were investigated and compared with four other taiwanese aboriginal groups. METHOD: A sample survey was conducted using a semi-structured clinical interview for AUDs among 252 subjects, aged 15 and above, from two Yami villages on Orchid Island. RESULTS: The prevalences of DSM-III-R and DSM-IV alcohol use disorders were 13.1% and 10.3% by one year, and 17.5% and 15.2% by lifetime, respectively, with a male excess. The risk for AUDs in Yami men was significantly associated with a lower educational level, a non-married status, and the length of stay in mainland Taiwan. A protective effect of Christian belief was evident for lifetime risk for AUDs. CONCLUSIONS: The lower prevalences of AUDs in Yami than in other aboriginal groups in Taiwan might be explained by social isolation of the former, and differences in drinking tradition, availability of alcohol, biological vulnerability, and the extent of acculturation between these groups.