Apoptosis signaling pathways mediated by cyclooxygenase-2 inhibitors in prostate cancer cells.
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Biomedical subjects
Publications and source records attributed to C Chen.
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OBJECTIVES: We evaluated the response of sildenafil citrate in patients with prostate cancer treated with three-dimensional conformal radiation therapy (3DCRT) whose sexual function (SF) was known prior to therapy initiation. METHODS: From March 1996 to April 1999, 24 men with median age of 68 years (range 51 to 77) had 3DCRT for localized prostate cancer (median prescribed dose to the planning target volume of 70.2 Gy). These men started taking sildenafil for relief of sexual dysfunction at a median time of 1 year after completing 3DCRT. We used the self-administered O'Leary Brief Sexual Function Inventory to evaluate in series SF and overall satisfaction at three time points. These points were (a) before initiation of all therapies (3DCRT or hormonal treatment [HT]) for prostate cancer, (b) before starting sildenafil (50 mg or 100 mg) but after completion of all therapies, and (c) at least 2 months afterward. Rates of SF were based on the number of men responding to a given question. We tested for significance of these two interventions to change SF by applying the Wilcoxon sign rank test. RESULTS: Prior to all treatments, 20 (87%) of 23 men were sexually potent, with 8 (36%) of 22 fully potent (little or no difficulty for penetration at intercourse). After 3DCRT with or without HT and prior to sildenafil use, 13 (65%) of the 20 potent patients remained potent, with only 2 (11%) of 19 being fully potent. The use of sildenafil citrate resulted in 21 (91%) of 23 men being potent, with 7 (30%) being fully potent. In 16 men responding to the satisfaction question, 10 (63%) and 12 (75%) were mixed to very satisfied with their sex life before 3DCRT with or without HT and after sildenafil citrate use, respectively. This response corresponded to potency and satisfaction scores significantly decreasing and subsequently increasing on average by one unit after 3DCRT and sildenafil citrate use, respectively (P <0.05). CONCLUSIONS: In men receiving 3DCRT for prostate cancer, these data indicate that sildenafil citrate is effective for restoring SF and associated satisfaction back to baseline before treatment.
Heats of formation of energetic materials can be obtained either experimentally or theoretically. In order to compare the results of the two methods, some correlation methods were proposed in this study. The molecular structures and heats of formation of nitrobenzenes, nitrotoluenes, nitroanilines, and nitrophenols were calculated by Dewar's AMI and Stewart's PM3 methods. Correlations of heats of formation between the theoretical calculations and experimental results were evaluated by using the multivariable linear regression method. Results indicate that there are very precise correlations. Based on these correlations, heats of formation of some aromatic nitro compounds can be predicted at 95% predictive interval without experimental analysis.
BACKGROUND: Prior reports suggested that bipolar patients in Taiwan had comparable long-term outcome to Western patients despite markedly lower rates of co-occurring substance use disorders. Thus, predictors of long-term outcome identified from Taiwanese bipolar samples may be less influenced by substance abuse. METHODS: One hundred and one patients with bipolar disorder (DSM-III-R) having been naturalistically treated for at least 15 years were recruited. These patients were annually followed for 2 years to assess overall outcome, psychiatric symptoms, rehospitalization, work, and social adjustment. A combination of medical record reviews and direct personal interviews with patients and family members provided the clinical data. RESULTS: Of these patients, 16.8% expressed a poor overall long-term outcome, even though only two (2.0%) patients exhibited alcohol dependence during the follow-up period. Multivariate regression showed that full compliance with medication was the strongest predictor of favorable overall long-term outcome, followed by younger age at onset and male sex. Younger age at onset as well as male sex, but not full compliance, also predicted a favorable psychosocial outcome. LIMITATIONS: Recruiting our sample from a clinical population with uncontrollable long-term treatment limits the generalizability of the findings. CONCLUSIONS: Compliance with pharmacotherapy is important to achieve a favorable overall long-term outcome of bipolar disorder. A portion of bipolar patients may have an unfavorable psychosocial outcome regardless of the psychopharmacological intervention or presence of substance abuse.
The non-metabolizable organic anion indocyanine green (ICG) has been shown previously to reduce markedly the biliary secretion of acetaminophen, particularly the glutathione conjugate of APAP (APAP-GSH), suggesting that this APAP metabolite may compete with other xenobiotics for excretion into the bile via a canalicular organic anion transport process. This study was conducted to determine whether changes in the biliary disposition of APAP induced by ICG could lead to alterations in susceptibility to APAP hepatotoxicity. To investigate this, groups of overnight-fasted male CD-1 mice received 30 micromol ICG/kg, intravenously, immediately prior to APAP dosing (500 mg/kg, ip). Controls were given propylene glycol vehicle. Mice were killed at 4 h after APAP challenge for immunochemical analysis of cytosolic protein arylation and determination of non-protein sulfhydryl (NPSH) depletion, or at 12 and 24 h for biochemical and histological assessment of liver injury. Elevated plasma sorbitol dehydrogenase activity and centrilobular hepatocellular necrosis was present in control mice receiving APAP at 12 and 24 h. Treatment with ICG did not alter susceptibility to APAP toxicity when measured at 12 h after challenge. However, the severity of histologic lesions in the ICG-APAP group was significantly lower at 24 h after challenge. Furthermore, treatment with ICG did not alter APAP-induced glutathione depletion or cytosolic protein arylation. These data suggest that the organic anion ICG has a protective effect on APAP toxicity that promotes a faster recovery from liver injury.
TNF-alpha induced an increase in intercellular adhesion molecule-1 (ICAM-1) expression in human A549 epithelial cells and immunofluorescence staining confirmed this result. The enhanced ICAM-1 expression was shown to increase the adhesion of U937 cells to A549 cells. Tyrosine kinase inhibitors (genistein or tyrphostin 23) or phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor (D 609) attenuated TNF-alpha-induced ICAM-1 expression. TNF-alpha produced an increase in protein kinase C (PKC) activity and this effect was inhibited by D 609. PKC inhibitors (staurosporine, Ro 31-8220, calphostin C, or Go 6976) also inhibited TNF-alpha-induced response. 12-O-Tetradecanoylphorbol-13-acetate (TPA), a PKC activator, stimulated ICAM-1 expression, this effect was inhibited by genistein or tyrphostin 23. Treatment of cells with TNF-alpha resulted in stimulation of p44/42 MAPK, p38, and JNK. However, TNF-alpha-induced ICAM-1 expression was not affected by either MEK inhibitor, PD 98059, or p38 inhibitor, SB 203580. A cell-permeable ceramide analog, C(2) ceramide, also stimulated the activation of these three MAPKs, but had no effect on ICAM-1 expression. NF-kappaB DNA-protein binding and ICAM-1 promoter activity were enhanced by TNF-alpha and these effects were inhibited by D 609, calphostin C, or tyrphostin 23, but not by PD 98059 or SB 203580. TPA also stimulated NF-kappaB DNA-protein binding and ICAM-1 promoter activity, these effects being inhibited by genistein or tyrphostin 23. TNF-alpha- or TPA-induced ICAM-1 promoter activity was inhibited by dominant negative PKCalpha or IKK2, but not IKK1 mutant. IKK activity was stimulated by both TNF-alpha and TPA, and these effects were inhibited by Ro 31-8220 or tyrphostin 23. These data suggest that, in A549 cells, TNF-alpha activates PC-PLC to induce activation of PKCalpha and protein tyrosine kinase, resulting in the stimulation of IKK2, and NF-kappaB in the ICAM-1 promoter, then initiation of ICAM-1 expression and neutrophil adhesion. However, activation of p44/42 MAPK, p38, and JNK is not involved in this event.
PURPOSE: There is increasing evidence that vitamin E (primarily alpha- and gamma-tocopherol) may reduce the risk of cardiovascular disease and some cancers, therefore it is important to understand factors that influence blood levels. METHODS: The correlates of serum alpha- and gamma-tocopherol were investigated among participants in the Women's Health Initiative (WHI), a 40-site disease prevention trial. Subjects were 1047 postmenopausal women aged 50-79 years, who provided fasting blood specimens and detailed information on diet, supplement use, and other factors at entry to the study (1994-96). RESULTS: Total serum cholesterol and triglycerides were highly correlated with serum alpha- and gamma-tocopherol concentrations and were controlled for in all analyses along with age, ethnicity and body mass index (BMI). Alpha and gamma-tocopherol were strongly negatively correlated (partial r = -0.69). The strongest predictor of serum tocopherols was average daily intake of vitamin E from supplements (partial r = 0.60 for alpha, r = -0.54 for gamma). Other factors associated with increased alpha- and/or decreased gamma-tocopherol concentrations were serum retinol and carotenoids, supplemental vitamin C, alpha-tocopherol intake from food, dietary fiber, and Hispanic ethnicity. Factors associated with lower alpha- and/or higher gamma-tocopherol concentrations included gamma-tocopherol intake from food, total fat intake, and BMI. Age, income, hormone use, and geographic location were "spuriously" associated with serum tocopherol levels through their association with supplement use, i.e., there was no such association among the subset of women not taking supplements. CONCLUSIONS: Vitamin E intake from supplements and BMI are the major independent predictors of serum tocopherol levels in women, whereas dietary factors only play a small role.
PURPOSE: Spontaneous abortion (SAB), the most common adverse pregnancy outcome, affects approximately 15% of clinically recognized pregnancies. Except for advanced maternal age and smoking, there are not well-established risk factors for SAB. Animal models associate increased fetal resorption or abortion with exposure to the pesticide dichlorodiphenyl trichloroethane (DDT), but epidemiologic investigations of DDT and SAB are inconsistent. We undertook a pilot investigation of the hypothesized association of DDT with SAB. METHODS: Participants in this case-control study were selected from a longitudinal study of reproductive effects of rotating shifts among female Chinese textile workers who were married, ages 22-34, nulliparous without history of SAB or infertility, and planning pregnancy. From 412 pregnancies, 42 of which ended in SAB, 15 SAB cases and 15 full-term controls were randomly selected and phlebotomized. Serum was analyzed for p,p'-DDT, o,p'-DDT, their metabolites (DDE and DDD), and other organochlorines including polychlorinated biphenyls. RESULTS: Cases and controls were nonsmokers and did not differ in age (mean 25 years), body mass index (BMI), passive smoke exposure, or workplace exposures. Cases had significantly (p < 0.05) higher serum levels of p,p'-DDE (22 vs.12 ng/g) and o,p'-DDE (0.09 vs. 0.05 ng/g) than controls. After adjustment for age and BMI, each ng/g serum increase in p,p'-DDE was associated with a 1.13 (CI, 1.02-1.26) increased odds of SAB. With adjustment of serum DDE levels for excretion via breastfeeding, DDE-associated increased odds of SAB remained significant with up to 7% declines in maternal serum DDE levels for each month of breastfeeding. CONCLUSIONS: A potential increased risk of SAB is associated with maternal serum DDE levels.
Extracts were prepared from Chinese chive (Allium tuberosum), cinnamon (Cinnamomum cassia), and corni fructus (Cornus officinalis) and used to evaluate their antimicrobial activity on common foodborne microorganisms, alone and in combination. The mixed extract, consisting of three extracts in equal volumes, showed an entire antimicrobial spectrum and had excellent stability to heat, pH, and storage. The mixed extract exhibited better inhibition on growth of Escherichia coli than potassium sorbate at 2-5 mg/mL. The mixed extract inhibited the growth of Pichia membranaefaciens at levels as low as 2 mg/mL. When the mixed extract was used in foods, the expected antimicrobial effect in orange juice, pork, and milk was observed. After gel filtration chromatography, each extract was partially purified into fractions, and one fraction in each extract showed enhanced antimicrobial activity. Overall, the mixed extract was of promising potential for incorporation into various food products for which a natural antimicrobial additive is desired.
A cyanobacterial hepatotoxin, nodularin-Har, having a homoarginine instead of an arginine in nodularin, was isolated from Nodularia PCC7804. The structure was elucidated as 1 on the basis of 2D NMR and FABMS. The LD(50) (mouse ip) value of 1 was 70 microg/kg.
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Three novel cDNAs encoding putative protein phosphatase-1 inhibitory protein (PPP1R14A) were isolated from human, mouse and rat. The human, mouse and rat PPP1R14A proteins were all of 147 amino acids sharing about 90% sequence identity to porcine CPI17, an inhibitor of protein phosphatase-1 holoenzyme. The protein sequence 33RHARVTVK40, which is important for the inhibitory potency of porcine CPI17, was conserved in mammalian PPP1R14A. Northern blot analysis showed that human PPP1R14A was highly expressed as a 600 bp transcript in heart, prostate, testis, ovary, colon, small intestine and pancreas, lowly in brain, placenta, skeletal muscle and spleen and lung. The distribution of mouse and rat PPP1R14A was more specific and different from that of human PPP1R14A, abundant in lung, moderate/abundant in testis, moderate in brain and low in heart. In addition, we mapped human PPP1R14A to chromosome 19q13.13-q13.2 by radiation hybrid mapping, and determined that the human PPP1R14A gene spanned a 5.1-kb region and consisted of four exons and three introns.
As access to gambling increases there is a corresponding increase in the frequency of addiction to gambling, known as pathological gambling. Studies have shown that a number of different neurotransmitters are affected in pathological gamblers and that genetic factors play a role. Polymorphisms at 31 different genes involved in dopamine, serotonin, norepinephrine, GABA and neurotransmitters were genotyped in 139 pathological gamblers and 139 age, race, and sex-matched controls. Multivariate regression analysis was used with the presence or absence of pathological gambling as the dependent variable, and the 31 coded genes as the independent variables. Fifteen genes were included in the regression equation. The most significant were the DRD2, DRD4, DAT1, TPH, ADRA2C, NMDA1, and PS1 genes. The r(2) or fraction of the variance was less than 0.02 for most genes. Dopamine, serotonin, and norepinephrine genes contributed approximately equally to the risk for pathological gambling. These results indicate that genes influencing a range of brain functions play an additive role as risk factors for pathological gambling. Multi-gene profiles in specific individuals may be of assistance in choosing the appropriate treatment.
The Escherichia coli gene recQ was identified as a RecF recombination pathway gene. The gene SGS1, encoding the only RecQ-like DNA helicase in Saccharomyces cerevisiae, was identified by mutations that suppress the top3 slow-growth phenotype. Relatively little is known about the function of Sgs1p because single mutations in SGS1 do not generally cause strong phenotypes. Mutations in genes encoding RecQ-like DNA helicases such as the Bloom and Werner syndrome genes, BLM and WRN, have been suggested to cause increased genome instability. But the exact DNA metabolic defect that might underlie such genome instability has remained unclear. To better understand the cellular role of the RecQ-like DNA helicases, sgs1 mutations were analyzed for their effect on genome rearrangements. Mutations in SGS1 increased the rate of accumulating gross chromosomal rearrangements (GCRs), including translocations and deletions containing extended regions of imperfect homology at their breakpoints. sgs1 mutations also increased the rate of recombination between DNA sequences that had 91% sequence homology. Epistasis analysis showed that Sgs1p is redundant with DNA mismatch repair (MMR) for suppressing GCRs and for suppressing recombination between divergent DNA sequences. This suggests that defects in the suppression of rearrangements involving divergent, repeated sequences may underlie the genome instability seen in BLM and WRN patients and in cancer cases associated with defects in these genes.
OBJECTIVE: To examine the associations between leptin levels and body mass index (BMI), fat distribution (reflected by waist to hip ratio and skinfold measurements), and blood pressure in a rural Chinese population. DESIGN AND SUBJECTS: A cross-sectional study of 294 participants who provided blood samples. MEASUREMENTS: Plasma concentrations of leptin, BMI, waist to hip ratio, skinfold thickness, and blood pressure. RESULTS: The average leptin concentration was 5.2 microg/l (3.1 for men and 7.3 for women). In univariate analyses, leptin levels were significantly correlated with BMI (r=0.47), abdominal skinfold thickness (r=0.53), triceps skinfold thickness (r=0.56), waist circumference (r=0.41), hip circumference (r=0.51), waist to hip ratio (r=0.17), and diastolic blood pressure (r=0.13). In multivariate analyses controlling for age, sex, education, current smoking, and alcohol use, independent associations between leptin levels and BMI, waist to hip ratio, waist circumference, and abdominal skinfold thickness remained. However, the significant association between leptin and blood pressure disappeared after adjusting for BMI, whereas the association between BMI and blood pressure persisted after adjusting for leptin level. CONCLUSIONS: We observed a strong positive relationship between overall adiposity and leptin levels in both men and women in a rural Chinese population. In addition, leptin concentrations were significantly associated with central obesity measured by waist to hip ratio and abdominal skinfold, independent of overall obesity. The observed positive association between leptin and blood pressure was largely explained by BMI. International Journal of Obesity (2001) 25, 121-125
AIMS: Lamotrigine, an antiepileptic drug, is cleared from the systemic circulation mainly by glucuronidation. The possibility of changes in the pharmacokinetics of lamotrigine in plasma owing to hepatic dysfunction has been evaluated. METHODS: Thirty-six subjects, including 24 patients with various degrees of liver cirrhosis and 12 healthy volunteers received a single 100 mg dose of lamotrgine. Blood samples were taken for 7 days in all subjects, except nine with severe cirrhosis, who had a 29 day blood sampling period. RESULTS: The pharmacokinetics of lamotrigine were comparable between the patients with moderate cirrhosis (corresponding to Child-Pugh grade A) and the healthy subjects. Plasma oral clearance mean ratios (90% confidence interval) in patients with severe cirrhosis without or with ascites (corresponding, respectively, to Child-Pugh grade B and C) to healthy subjects were, respectively, 60% (44%, 83%) and 36% (25%, 52%). Plasma half-life mean ratios (90% confidence interval) in these two patient groups to healthy subjects were, respectively, 204% (149%, 278%) and 287% (202%, 408%). CONCLUSIONS: Lamotrigine administered as a single oral dose of 100 mg was well tolerated in all groups. Initial, escalation and maintenance doses should generally be reduced by approximately 50 or 75% in patients with Child-Pugh Grade B or C cirrhosis. Escalation and maintenance doses should be adjusted according to clinical response.
BACKGROUND: Atrial natriuretic peptide (ANP) is a hormone with well-known diuretic and vasodilating properties. Recently it was reported that ANP could increase the peritoneal fluid formation and increase peritoneal solute clearance. This study investigated the effect of ANP on peritoneal fluid and solute transport characteristics. METHODS: Eighteen male Sprague-Dawley rats were divided into three groups. A four-hour dwell study using 25 mL 2.27% glucose dialysis solution with 50 microg/kg ANP (N = 6, H-ANP) or 5 microg/kg ANP (N = 6, L-ANP) or without ANP (N = 8, control) and frequent dialysate and blood sampling was done in each rat. Radiolabeled human albumin (RISA) was added to the solution as an intraperitoneal volume marker. RESULTS: The intraperitoneal volume was significantly higher in the H-ANP group as compared with the control group and the L-ANP group. The drainage volume was 26.2 +/- 1.1, 25.5 +/- 0.7, and 29.8 +/- 0.8 mL for the control, L-ANP, and H-ANP groups, respectively (P < 0.01). This was related to significant differences in the peritoneal fluid absorption rates (K(E); estimated as the RISA elimination coefficient): 39 +/- 3, 38 +/- 3, and 19 +/- 4 microL/min, and in the direct lymphatic absorption rate (K(EB); estimated as the clearance of RISA from dialysate to blood): 7 +/- 1, 6 +/- 1, and 4 +/- 1 microL/min for the control, L-ANP, and H-ANP groups, respectively (all P < 0.01). No differences were found in the intraperitoneal volume, K(E), and K(EB) between the control group and the L-ANP group. The diffusive mass transport coefficient (K(BD)) for urea, sodium, potassium, and total protein did not differ among the three groups. However, the glucose D/D(0) was significantly higher, and the K(BD) for glucose was significantly lower in the H-ANP group as compared with the other two groups. Solute clearances (+175% for sodium and +26% for potassium) were significantly increased in the H-ANP group, mainly as a result of the increased fluid removal in this group. CONCLUSIONS: Our results suggest that ANP may decrease peritoneal fluid absorption (by 51%, partially because of decreasing the direct lymphatic absorption), resulting in a significant increase in peritoneal fluid removal and small solute clearances. While the basic diffusive permeability of the peritoneal membrane was not changed, the peritoneal glucose absorption was retarded by adding ANP to peritoneal dialysate, perhaps through interaction of ANP with glucose metabolism.