Neoadjuvant immunotherapy for resectable hepatocellular carcinoma: a systematic review and meta-analysis.

OBJECTIVE: Immune checkpoint inhibitors have initiated a new era in hepatocellular carcinoma (HCC) treatment. For improving the prognosis of patients with resectable HCC and reducing postoperative recurrence, immunotherapy is being developed in the neoadjuvant setting. However, the efficacy and safety of neoadjuvant immunotherapy remain unclear. MATERIALS AND METHODS: PubMed, Embase, Medline, and Cochrane Library databases were systematically searched for the clinical trials of neoadjuvant immunotherapy for resectable HCC. A single-arm meta-analysis was conducted to calculate the odds ratio and 95% confidence interval (CI), and statistical transformation was performed to obtain the pooled rate P(t) and its CI. Subgroup analyses were performed according to the type of combination therapy. RESULTS: 81 patients from four studies were included in this meta-analysis. In patients with resectable HCC, the pooled major pathological response (MPR) rate and pathological complete response (pCR) rate for neoadjuvant immunotherapy were 0.23 (95% CI, 0.14-0.36) and 0.19 (95% CI, 0.10-0.30), respectively. The pooled objective response rate (ORR) was 0.18 (95% CI, 0.10-0.28), comparable to the results of immunotherapy for advanced HCC. The overall treatment-related adverse events (TRAE) rate was 0.80 (95% CI, 0.68-0.89), but the grade ≥3 TRAE rate was low at 0.21 (95% CI, 0.13-0.33). The pooled surgical resection rate and surgical delay rate were 0.95 (95% CI, 0.85-0.98) and 0.05 (95% CI, 0.02-0.16), respectively. Subgroup analyses revealed no significant differences in clinical outcomes between immunotherapy combinations. CONCLUSIONS: This meta-analysis provides preliminary evidence of the efficacy and safety of neoadjuvant immunotherapy for HCC, suggesting that it is a promising perioperative treatment option. Conclusive evidence supporting its use requires additional data from large-scale clinical trials.

ABCC1 is a predictive biomarker for prognosis and therapy in hepatocellular carcinoma.

OBJECTIVE: Liver neoplasm is one of the most fatal malignancies worldwide, among which hepatocellular carcinoma (HCC) (MIM #114550, https://omim.org/) is the most prevalent type. ABCC1 (MIM *158343) is a membrane-bound protein that relies on ATP hydrolysis to transport substrates and is associated with tumour drug resistance and malignant potential. However, the relationship between ABCC1, HCC prognosis, and immune infiltration remains elusive. MATERIALS AND METHODS: We analysed the mRNA expression of ABCC1 using data from public databases. Immunohistochemistry staining was performed to identify ABCC1 expression in tumour samples. We further investigated the correlation between ABCC1 and clinicopathological features. We investigated the connection between ABCC1 and HCC prognosis using survival and Cox regression analyses. We investigated the underlying pathways of ABCC1 in HCC using functional enrichment analysis and GSEA. We determine the relationship between ABCC1 and immune cell infiltration via an integrated immune landscape analysis. RESULTS: Our investigation revealed the upregulation of ABCC1 expression in HCC (p < 0.01), which was verified in clinical samples (p < 0.01). In addition, ABCC1 is adversely associated with HCC clinical features and prognosis (p < 0.05). GO/KEGG analysis and GSEA identified that ABCC1 participates in multiple immune- and tumour-related pathways (p < 0.05). Immune cell infiltration analysis indicated that ABCC1 was positively correlated with various immune cells, among which, the strongest correlation was with macrophages (p < 0.001). Furthermore, we observed significant variations in immune checkpoints between the ABCC1-low and ABCC1-high groups (p < 0.01). This indicated that patients with a high expression of ABCC1 might respond poorly to immune checkpoint blockade (ICB) therapy (p = 9.2e-07). CONCLUSIONS: Our study identified ABCC1 as a predictor of HCC prognosis and response to therapy.

Structural maintenance of chromosomes 2 is identified as an oncogene in bladder cancer in vitro and in vivo.

Taurine upregulated gene 1 (TUG1) has been found to promote bladder cancer cell growth in our recent research. In this study, TUG1-depleted bladder cancer cells were used to identify potent players in bladder cancer. Human gene expression arrays were used for transcriptome profiling of TUG1-depleted bladder cancer cells. Cell proliferation was analyzed by MTT assay. Cell apoptosis and cell cycle were analyzed by flow cytometry. Colony formation assay was used to observe the changes of colony formation rates. Xenograft formation assay was performed in nude mice. Immunohistochemical staining was used to test the gene expression levels in tissues from bladder cancer patients. We found that deregulated genes were strongly enriched in cell cycle or pathways in cancer in TUG1-depleted bladder cancer cells. Structural maintenance of chromosomes 2 (SMC2) was inhibited after TUG1 knockdown. The depletion of TUG1 or SMC2 led to G2/M phase arrest in bladder cancer cells. SMC2 depletion inhibited bladder cancer cell proliferation, promoted apoptosis, decreased colony formation, and reduced tumor growth in xenograft nude mice. Overexpression of SMC2 restored the growth of TUG1-depleted cells. The expression levels of SMC2 were higher in human bladder cancer tissues than that in paired normal tissues. Our data suggest that SMC2 is an oncogene in bladder cancer and depletion of SMC2 might have potential therapeutical significance in bladder cancer.

Global meta-analysis on the responses of soil extracellular enzyme activities to warming.

Soil enzymes play critical roles in the decomposition of organic matter and determine the availability of soil nutrients, however, there are significant uncertainties in regard to how enzymatic responses to global warming. To reveal the general response patterns and controlling factors of various extracellular enzyme activities (EEA), we collected data from 78 peer-reviewed papers to investigate the responses of extracellular enzyme activities (EEA), including ß-1,4-glucosidase (BG), ß-d-cellobiosidase (CBH), ß-1,4-xylosidase (XYL), leucine amino peptidase (LAP), N-acetyl-glucosaminidase (NAG), urease (URE), phosphatase (PHO), peroxidase (PER), phenol oxidase (POX), and polyphenol oxidase (PPO), to experimental warming. Our results showed that warming treatments increased soil temperature by 1.9 °C on average. The oxidative EEA, calculated as the sum of PER, POX and PPO, was on average stimulated by 9.4% under warming. However, the responses of C acquisition EEA (the sum of BG, CBH and XYL), N acquisition EEA (the sum of LAP, NAG and URE), and P acquisition EEA to warming had large variations across studies. The warming effects on C, N, P acquisition EEA and oxidative EEA tended to increase with soil warming magnitude and duration as well as the mean annual temperature. The response of C acquisition EEA to warming was positively correlated with fungal biomass, while that of P acquisition EEA had positive relationships with fungi: bacteria ratios. The response of oxidative EEA was negatively correlated with the abundance of gram-positive bacterial biomass. Our results suggested that warming consistently stimulated oxidative EEA, but had diverse effects on hydrolytic EEA, which were dependent on the warming magnitude or duration, or environmental factors. The observed relationships between changes in microbial traits and extracellular enzymes suggested that microbial compositions drive changes in enzyme decomposition under warming. Thus, incorporation of microbial modification in biogeochemistry models is essential to better predict ecosystem carbon and nutrient dynamics.

Difficulties and practices regarding information provision among Korean and Italian nurses.

AIM: To investigate nurses' opinions and practices of providing information in a global context through cultural comparison. BACKGROUND AND INTRODUCTION: Providing sufficient information to patients about nursing interventions and plans is essential for patient-centred care. While many countries have specific legislation making information delivery to patients a legal duty of nurses, no such legislation exists in both the Republic of Korea and Italy; nurses' only guidance is the deontological code. METHODS: This was a cross-sectional survey study involving a convenience sample of 174 Korean nurses and 121 Italian nurses working in internal medicine and surgery at university hospitals. Data were collected using a self-administered questionnaire between February and November 2014. The questionnaire assessed demographic and professional characteristics, and difficulties and practices regarding information provision. RESULTS: Korean and Italian nurses significantly differed in all demographic and professional characteristics. More Korean than Italian participants reported that their role in providing information was well explained within their teams, but both groups reported the same level and type of difficulties in delivering information. Nurses in both countries regularly informed patients about medications and nursing procedures, but provided information about nursing care plans less frequently. Few nurses frequently provided information to relatives instead of patients. CONCLUSIONS: Despite cultural, demographic and professional differences between Korean and Italian nurses, their difficulties and practices in information delivery to patient were similar. IMPLICATIONS FOR NURSING AND HEALTH POLICY: Hospital managers and policymakers should be aware that nurse-patient communication can be impaired by organizational factors, patient characteristics or the interaction among providers. Educational interventions and strategies are needed to increase information provision to patients about nursing care plans.

[Research progress of mutational spectrum and pathophysiology of WFS1 gene in Wolfram syndrome and nonsyndromic low frequency sensorineural hearing loss].

Compound homozygous or heterozygous mutations in WFS1 can lead to autosomal recessive Wolfram syndrome (WS), and heterozygous mutations in WFS1 can lead to autosomal dominant non-syndromic low frequency sensorineural hearing loss (LFSNHL). In addition, mutations in the WFS region has relationship with diabetes and psychiatric diseases. In this paper, we provide an overview of genetic research with different phenotypes, including WS and LFSNHL.

Eicosapentaenoic acid attenuates dexamethasome-induced apoptosis by inducing adaptive autophagy via GPR120 in murine bone marrow-derived mesenchymal stem cells.

Long-term use of glucocorticoids is a widespread clinical problem, which currently has no effective solution other than discontinuing the use. Eicosapentaenoic acid (EPA), an omega-3 long chain polyunsaturated fatty acid (n-3 PUFA), which is largely contained in fish or fish oil, has been reported to promote cell viability and improve bone metabolism. However, little is known about the effects of EPA on dexamethasome (Dex)-induced cell apoptosis. In this study, we showed that EPA-induced autophagy of murine bone marrow-derived mesenchymal stem cells (mBMMSCs). Meanwhile, EPA, but not arachidonic acid (AA), markedly inhibited Dex-induced apoptosis and promoted the viability of mBMMSCs. We also observed that EPA-induced autophagy was modulated by GPR120, but not GPR40. Further experiments showed that the mechanism of EPA-induced autophagy associated with GPR120 modulation involved an increase in the active form of AMP-activated protein kinase and a decrease in the activity of mammalian target of RAPA. The protective effect of EPA on Dex-induced apoptosis via GPR120-meditated induction of adaptive autophagy was supported by in vivo experiments. In summary, our findings may have important implications in developing future strategies to use EPA in the prevention and therapy of the side effects induced by long-term Dex-abuse.

[Effect of N-acetylcysteine inhalation on ventilator-associated pneumonia caused by biofilm in endotracheal tubes].

OBJECTIVE: To observe the formation of the biofilm in endotracheal tubes, the characteristics of etiology, drug resistance and effect on the biofilm and ventilator-associated pneumonia (VAP) of inhaled N-acetylcysteine (NAC). METHOD: We selected 117 tracheally intubated and undergoing mechanical ventilation for ≥48 h in our hospital ICU from September 2010 to August 2012. All the cases were randomly divided into control group (60 cases) and study group (57 cases). The patients in the study group were treated with different doses of aerosolized NAC according to different ages, starting the first administration within 12 hours of mechanical ventilation, once every 8 hours, until stopping mechanical ventilation. Comparison was performed on the two groups in biofilm structure under the scanning electron microscopy, biofilm culture positive rate, VAP incidence, the etiology and drug resistance of the lower airway secretions and biofilms. RESULT: (1) Electron microscopy showed that biofilm had formed in the endotracheal tube inner wall in early period of mechanical ventilation. With prolonged mechanical ventilation, biofilm structure improved. At the same time of mechanical ventilation, the thickness of biofilm in the study group decreased as compared with the control group. (2) Biofilm culture positive rate and incidence of ventilator-associated pneumonia decreased in the study group compared with in the control group (65%(37/57) vs. 80%(48/60), P<0.05; 11% (6/57)vs. 32%(19/60), P<0.01). (3) A large number of pathogenic bacteria colonized in the biofilm and gram-negative bacilli dominated. With prolonged mechanical ventilation, the cultured pathogens converged from the lower airway secretions and biofilm. CONCLUSION: With prolonged mechanical ventilation, biofilm structure was improved. Inhalation of NAC can inhibit biofilm formation and reduce the incidence of VAP.

Association between IL6 polymorphism and risk of cerebral infarction.

We conducted a case-control study to investigate the influence of IL6 -174G/C (rs1800795) and -572C/G (rs1800796) genetic variants on the development of cerebral thrombosis in a Chinese population. This study included 305 cerebral infarction patients and 326 control subjects enrolled between May 2012 and May 2014. The genotyping of IL6 -174G/C (rs1800795) and -572C/G (rs1800796) polymorphisms was performed using polymerase chain reaction combined with restriction fragment length polymorphism analysis. By using logistic regression, we found that when compared with the wild-type genotype, CC and GC+CC IL6 -174G/C (rs1800795) genotypes were associated with an increased risk of cerebral infarction. Odds ratios (and 95% confidence intervals) were calculated to be 3.10 (1.57-6.41) and 1.63 (1.14-2.33) for the CC and GC+CC genotypes, respectively. In conclusion, our study suggests that the CC genotype and C allele of the IL6 -174G/C (rs1800795) polymorphism are associated with an increased risk of cerebral infarction.

Organic anion transporting polypeptide-mediated transport of, and inhibition by, asunaprevir, an inhibitor of hepatitis C virus NS3 protease.

Asunaprevir (ASV), an investigational, highly protein-bound inhibitor of hepatitis C virus NS3 protease, shows considerable hepatic compartmentalization in animal models. Preclinical data showed ASV inhibition of human OATP1B1 (IC50 = 0.3 µM), OATP2B1 (0.27 µM), and, to a lesser extent OATP1B3 (3.0 µM), confirmed by modest (<2-fold) clinical elevations in rosuvastatin exposure with concomitant ASV. Although no significant OATP transport of ASV was observed in vitro at standard micromolar assay concentrations, clinical coadministration of ASV with a single dose of the OATP inhibitor rifampin gave large, variable increases in ASV plasma Cmax (21-fold mean) and AUCinf (15-fold mean), consistent with reduced hepatic uptake. In vitro reevaluation at therapeutically relevant low-nanomolar concentrations of unbound ASV showed active, saturable human hepatocyte uptake (Km = 0.685 µM) and rifampin-reversible transport by OATP1B1 and OATP2B1, but not OATP1B3. At therapeutically relevant concentrations, ASV is therefore a sensitive substrate for, and weak inhibitor of, human OATP1B1, 1B3 and 2B1.

Dexamethasone inhibits the effect of paclitaxel on human ovarian carcinoma xenografts in nude mice.

BACKGROUND: Recent studies showed that dexamethasone (DEX) could render cancer cells resistant to paclitaxel (PTX) induced apoptosis though an unknown mechanism. AIM: This study aimed to evaluate the influence of DEX pretreatment on the anti-tumor effect of PTX in an in vivo xenograft model with grafted ovarian cancer SKOV-3 cells innude mice. MATERIALS AND METHODS: The xenograft procedure was performed, and the nude mice were grouped into four cohorts of ten that received the following treatments: Control group, DEX group, PTX group and DEX+PTX group. Individual treatments were administered once every three days for a total of 6 courses. The growth of tumors and the inhibition rates were measured. Changes in tissue morphology and cellular ultrastructure were observed using light and transmission electron microscopy. Immunohistochemistry was performed to examine the expression of Ki-67, Bcl-xL and cleaved caspase-3. RESULTS: Premedication with DEX reduced the inhibitory effect of PTX on tumor growth by approximately 20% compared to the PTX-only-treated group in the ovarian carcinoma xeno-grafted mice. Hematoxylin-eosin (H&E) staining revealed that significantly fewer cells exhibited vacuolization and apoptosis in the DEX + PTX group compared to the PTX group. Apoptotic characteristics including karyopyknosis, nuclear chromatin condensation along the nuclear membrane and aggregation were observed in both DEX+PTX and PTX groups under electron microscopy. However, these characteristics were less significant in the DEX+PTX group than those in the PTX group. The immunohistochemistry demonstrated that protein expression levels of Ki-67 and Bcl-xL were significantly increased, whereas cleaved caspase-3 decreased in the DEX+PTX group, compared to PTX group (p < 0.0125). CONCLUSIONS: DEX inhibits the therapeutic efficacy of PTX in a human ovarian carcinoma SKOV-3 xenograft model.

Down-regulation of TCF21 is associated with poor survival in clear cell renal cell carcinoma.

Transcription factor 21 (TCF21) has been identified as a candidate tumor suppressor at 6q23-q24 that is epigenetically inactivated in many types of human cancers. We recently found that TCF21 methylation level was significantly increased in clear cell renal cell carcinoma (ccRCC). The purpose of this study was to investigate the prognostic impact of TCF21 expression in ccRCC and analyze the relationship between TCF21 expression and methylation level. We used real-time PCR and immunohistochemical staining to detect the expression of TCF21, and used methylation specific-PCR (MS-PCR) to determine the methylation status of TCF21 in ccRCC samples and cell line 786-O. The results showed that TCF21 expression level in ccRCC samples was significantly lower than in normal adjacent tissue samples (NAT samples). The Kaplan-Meier survival analysis demonstrated that TCF21 was a significant prognosticator of cancer-specific survival (p=0.001). Furthermore, the DNA demethylating agent 5'-azacytidine restored part of TCF21 expression by suppressing TCF21 methylation in 786-O. The methylation level of TCF21 in ccRCC samples was much higher than in NAT samples. These results suggest that the expression of TCF21 was an independent prognostic factor for poor survival in patients with ccRCC. Aberrant methylation was an important reason for the down-regulation the expression of TCF21, and may be associated with tumorigenesis in ccRCC.

Radiosurgery for metastatic spinal tumors: follow-up MR findings.

BACKGROUND AND PURPOSE: MR imaging is the primary tool for evaluation and monitoring of spinal tumors. We retrospectively analyzed the MR imaging findings before and after SRS for metastatic spinal tumors. MATERIALS AND METHODS: We reviewed MR imaging findings on 79 metastatic spinal tumor lesions in 44 patients (29 male and 15 female)who had undergone radiosurgery between November 2003 and April 2008. Posttreatment MR imaging was evaluated retrospectively for 3 aspects: 1) changes in tumor volume; 2) changes in T2 signal intensity;and 3) changes in contrast enhancement patterns. RESULTS: With regard to tumor volume on MR images, 32 lesions(40.5%) decreased in volume (group 1), 39 (49.4%) showed no change (group 2), and 8 (10.1%) increased in volume (group 3). T2 signal intensities were unchanged in 4 lesions (type 1), homogeneously increased in 3 (type 2), and changed to a homogeneously dark signal in 4 (type 4). The T2 signal intensity was increased and inter mixed with dark signal intensity (type 3) in 68 lesions. A decrease in contrast enhancement with or without non-enhancing foci was seen in 73 lesions. A persistent homogeneous enhancement pattern was seen in all 4 of the type 1 lesions, in 1 of the 3 type 2 lesions, and in 1 of the 68 type 3 lesions. CONCLUSIONS: Main MR imaging features of locally controlled metastatic spinal tumors included no increase in tumor volume, increased T2 signal intensity with intermixed T2 dark signal intensity,and decreased contrast enhancement. Follow-up MR imaging also provided several patterns of tumor recurrence [corrected].

Involvement of Mrp2/MRP2 in the species different excretion route of benzylpenicillin between rat and human.

1. The purpose of this study was to investigate the involvement of rat Mrp2 and human MRP2 in benzylpenicillin transport using canalicular liver plasma membrane (cLPM) vesicles isolated from Sprague-Dawley or Easai hyperbilirubinemic (EHBR) rats, and MDCKII cells overexpressing MRP2. 2. The adenosine triphosphate (ATP)-dependent uptake of benzylpenicillin and oestradiol-17beta-D-glucuronide (E(2)17betaG), a representative substrate for Mrp2, into EHBR-cLPM vesicles was decreased relative to that seen with control-cLPM vesicles, which may reflect the absence of Mrp2 in the EHBR. The ATP-dependent uptake of taurocholate, which is not a substrate for Mrp2, was similar in both control and EHBR-cLPM vesicles. The concentration dependence of ATP-dependent benzylpenicillin uptake was reflected in a K(m) of 44.0 microM and a V(max) of 508.4 pmol mg(-1) min(-1). Additional inhibition studies using E(2)17betaG and methotrexate as representative substrates for Mrp2/MRP2 demonstrated the involvement of rat Mrp2, but not human MRP2, in benzylpenicillin efflux. Benzylpenicillin appears not to be a substrate for or inhibitor of other human efflux transporters such as MDR1, MRP1, MRP3, or BCRP. 3. In conclusion, rat Mrp2, but not human MRP2, plays an important role in ATP-dependent benzylpenicillin uptake in the bile canalicular membrane, which may explain why biliary excretion of benzylpenicillin is high in the rat but negligible in humans.

Percutaneous insertion of Zilver stent in malignant biliary obstruction.

BACKGROUND: We evaluated the clinical efficacy and technical feasibility of the percutaneously inserted self-expandable nitinol stent (Zilver stent) for palliation of malignant biliary obstruction. METHODS: Seventeen patients with malignant tumors involving the intra- or extrahepatic bile duct who presented with obstructive jaundice underwent percutaneous insertion of a self-expandable nitinol stent. We retrospectively reviewed the hospital records of patients and evaluated the technical feasibility on stent placement, complications, patient survival, and duration of stent patency. RESULTS: Percutaneous biliary stenting with 27 Zilver stents was performed in 17 patients with malignant biliary obstruction. Technical success was 95%. Malposition of the stent was encountered in one patient. Minor technical problems were encountered in two patients: the introducer tip was broken during stent insertion, so endoscopic removal was done. Mean follow-up period for the 17 patients was 182 days (range 29-485 days): nine patients died of progressive disease at a mean follow-up of 151 days (range 61-371days) after stent insertion and eight patients remained alive at the final follow-up of 216 days (range 29-485 days). The median survival period for all patients was 277 days. The stent occlusion rate was 26% and the mean patency period was 280 days. In five patients, seven stents were obstructed by tumor ingrowth and overgrowth. Stent patency rates were 100%, 100%, 75%, 61%, and 41% at 1, 2, 3, 6, and 12 months, respectively. A late complication, erosive bleeding of the hepatic artery by the stent, developed in one patient. CONCLUSION: Percutaneous biliary stenting using the nitinol stent is technically feasible and safe and clinically efficacious treatment for malignant biliary obstruction, even with a minor technical problem during stent insertion.

Regulation of Nur77 nuclear export by c-Jun N-terminal kinase and Akt.

Proapoptotic nuclear receptor family member Nur77 translocates from the nucleus to the mitochondria, where it interacts with Bcl-2 to trigger apoptosis. Nur77 translocation is induced by certain apoptotic stimuli, including the synthetic retinoid-related 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalenecarboxylic acid (AHPN)/CD437 class. In this study, we investigated the molecular mechanism by which AHPN/CD437 analog (E)-4-[3-(1-adamantyl)-4-hydroxyphenyl]-3-chlorocinnamic acid (3-Cl-AHPC) induces Nur77 nuclear export. Our results demonstrate that 3-Cl-AHPC effectively activated Jun N-terminal kinase (JNK), which phosphorylates Nur77. Inhibition of JNK activation by a JNK inhibitor suppressed 3-Cl-AHPC-induced Nur77 nuclear export and apoptosis. In addition, several JNK upstream activators, including the phorbol ester TPA, anisomycin and MAPK kinase kinase-1 (MEKK1), phosphorylated Nur77 and induced its nuclear export. However, Nur77 phosphorylation by JNK, although essential, was not sufficient for inducing Nur77 nuclear export. Induction of Nur77 nuclear export by MEKK1 required a prolonged MEKK1 activation and was attenuated by Akt activation. Expression of constitutively active Akt prevented MEKK1-induced Nur77 nuclear export. Conversely, transfection of dominant-negative Akt or treatment with a phosphatidylinositol 3-kinase (PI3-K) inhibitor accelerated MEKK1-induced Nur77 nuclear export. Furthermore, mutation of an Akt phosphorylation residue Ser351 in Nur77 abolished the effect of Akt or the PI3-K inhibitor. Together, our results demonstrate that both activation of JNK and inhibition of Akt play a role in translocation of Nur77 from the nucleus to the cytoplasm.

Physicochemical parameters responsible for the affinity of methotrexate analogs for rat canalicular multispecific organic anion transporter (cMOAT/MRP2).

PURPOSE: Canalicular multispecific organic anion transporter (cMOAT/MRP2) is known to exhibit a broad substrate specificity toward amphiphatic organic anions, including methotrexate (MTX). The present study aims to identify the physicochemical properties of MTX derivatives that correlate with recognition specificity by cMOAT/MRP2. METHODS: We examined the inhibitory effect of MTX and 24 analogs on the transport of [3H]-S-(2,4-dinitrophenyl)glutathione by cMOAT/MRP2. The affinity constants of these compounds were compared with their physicochemical parameters. The primary active transport of several compounds was also confirmed. RESULTS: The affinity constants closely correlated with the octanol/water partition coefficient (clogP), and a linear combination of polar and nonpolar surface areas. The affinity for cMOAT/MRP2 also closely correlated with the molecular weight, which also showed a significant correlation with nonpolar surface area and clogP. CONCLUSIONS: Recognition by cMOAT/MRP2 depends on a balance of dynamic surface properties between the polar and nonpolar regions of MTX analogs. The so-called "molecular weight threshold" for the cMOAT/MRP2 affinity of these compounds can be explained by their physicochemical parameters, especially their nonpolar surface areas.

Malignant esophagogastric junction obstruction: palliative treatment with an antireflux valve stent.

The authors assessed the efficacy of an antireflux valve stent in the palliation of malignant esophagogastric junction (EGJ) obstruction after in vitro testing of the stent. Seventeen patients with inoperable malignant EGJ obstruction were treated. Antireflux valves, made of three polyurethane leaflets, were attached to the distal part of the stent to prevent reflux. When the flow rate of normal saline was 100 mL/sec in the forward direction, the valve fully opened at a pressure of 10 mm Hg. When the flow rate of normal saline was 0.35 mL/sec in the backward direction, the valve nearly completely closed at a pressure of 10 mm Hg. Stent placement was successful in all patients without complications. The median dysphagia score decreased significantly, from 3.0 (dysphagia to liquids) to 1.0 (dysphagia to normal solid food) (P < .0005). No patients experienced reflux symptoms. There was one case of stent migration. A valve stent that can prevent major reflux is an effective device for the palliation of malignant EGJ obstruction.

Malignant obstruction of gastric outlet and duodenum: palliation with flexible covered metallic stents.

PURPOSE: To assess the usefulness of flexible covered metallic stents in the palliation of malignant obstruction of the gastric outlet and duodenum. MATERIALS AND METHODS: Twenty-four consecutive patients with malignant obstruction of the gastric outlet (n = 22) or duodenum (n = 2) underwent palliative treatment with self-expandable flexible covered metallic stents. Fourteen patients had advanced gastric carcinoma at the antrum and/or pylorus, and eight had obstruction at the anastomosis site of previous gastrojejunostomy. Complications and clinical status were investigated during the study period. RESULTS: The technical success rate was 75% (18 of 24 patients). Twenty-one stents were placed in 18 patients by using an introducer 6 (n = 7) or 8 mm (n = 14) in diameter. The mean follow-up period was 3.4 months (range, 1 week to 9 months). Symptoms improved in 12 (67%) patients after the procedure. There was no change in symptoms in five and a decrease in one. Twelve patients died during the follow-up period (mean survival, 4.3 months). The complication rate was 25% (six of 24 patients), including stent migration (n = 5) and fracture (n = 3). CONCLUSION: Flexible covered metallic stent placement can be useful for palliation in patients with malignant obstruction of the gastric outlet or duodenum.

Biophysical characterization of recombinant human Bcl-2 and its interactions with an inhibitory ligand, antimycin A.

Apoptosis is an essential physiological process, regulated by the family of Bcl-2-related proteins. However, the molecular mechanism by which Bcl-2 regulates apoptosis still remains elusive. Here we report the functional studies of recombinant human Bcl-2 with the deletion of 22 residues at the C-terminal membrane-anchoring region (rhBcl-2Delta22). Characterization of rhBcl-2Delta22 showed that the recombinant protein is homogeneous and monodisperse in nondenaturing solutions, stable at room temperature in the presence of a metal chelator, and an alpha-helical protein with unfolding of secondary structure at a T(m) of 62.8 degrees C. Optimal membrane pore formation by rhBcl-2Delta22 required negatively charged phospholipids. The existence of a hydrophobic groove in rhBcl-2Delta22 was demonstrated by the fluorescence enhancement of the hydrophobic ANS probe with which a pro-apoptotic Bak BH3 peptide competed. The respiratory inhibitor antimycin A also bound to the hydrophobic groove of rhBcl-2Delta22 with a K(d) of 0.82 microM. The optimal binding conformation of antimycin A was predicted from molecular docking of antimycin A with the hBcl-2 model created by homology modeling. Antimycin A selectively induces apoptosis in cells overexpressing Bcl-2, suggesting that hydrophobic groove-binding compounds may act as selective apoptotic triggers in tumor cells.