MDCK (Madin-Darby canine kidney) cells: A tool for membrane permeability screening

The goal of this work was to investigate the use of MDCK (Madin-Darby canine kidney) cells as a possible tool for assessing the membrane permeability properties of early drug discovery compounds. Apparent permeability (Papp) values of 55 compounds with known human absorption values were determined using MDCK cell monolayers. For comparison, Papp values of the same compounds were also determined using Caco-2 cells, a well-characterized in vitro model of intestinal drug absorption. Monolayers were grown on 0. 4-microm Transwell-COL membrane culture inserts. MDCK cells were seeded at high density and cultured for 3 days, and Caco-2 cells were cultured under standard conditions for 21 to 25 days. Compounds were tested using 100 microM donor solutions in transport medium (pH 7.4) containing 1% DMSO. The Papp values in MDCK cells correlated well with those in Caco-2 cells (r2 = 0.79). Spearman's rank correlation coefficient for MDCK Papp and human absorption was 0.58 compared with 0.54 for Caco-2 Papp and human absorption. These results indicate that MDCK cells may be a useful tool for rapid membrane permeability screening.

Human RPB5, a subunit shared by eukaryotic nuclear RNA polymerases, binds human hepatitis B virus X protein and may play a role in X transactivation

The X gene of human hepatitis B virus encodes the polypeptide HBx which transactivates viral and host genes through a variety of cis-acting enhancer elements present in RNA polymerases I, II and III promoters. To better understand the mechanism of X transactivation, we cloned cDNAs of proteins that bind HBx. Here we demonstrate that one of these cDNAs is a full-length cDNA of human RPB5, a subunit shared by RNA polymerases. The HBx transactivation domain and the central region of human RPB5 were necessary for the specific binding of the two proteins as shown by: (i) in vitro assays using deletion mutants of fusion proteins; (ii) in vivo assays which detect associated proteins by co-immunoprecipitation of the non-fused proteins from transfected HepG2 cells. Over-expressed HBx seemed to associate with assembled forms of endogenous human RPB5 in HBx-transfected cells, since the endogenous RPB5 co-immunoprecipitated with HBx. The HBx binding region of human RPB5 by itself stimulated chloramphenicol acetyltransferase activities from several different reporters having X-responsive element(s). Our results support the idea that the interaction of HBx and human RPB5 can facilitate HBx transactivation and that human RPB5 has a domain which can communicate with transcriptional regulators.

A nuclear factor, ASC-2, as a cancer-amplified transcriptional coactivator essential for ligand-dependent transactivation by nuclear receptors in vivo

Many transcription coactivators interact with nuclear receptors in a ligand- and C-terminal transactivation function (AF2)-dependent manner. We isolated a nuclear factor (designated ASC-2) with such properties by using the ligand-binding domain of retinoid X receptor as a bait in a yeast two-hybrid screening. ASC-2 also interacted with other nuclear receptors, including retinoic acid receptor, thyroid hormone receptor, estrogen receptor alpha, and glucocorticoid receptor, basal factors TFIIA and TBP, and transcription integrators CBP/p300 and SRC-1. In transient cotransfections, ASC-2, either alone or in conjunction with CBP/p300 and SRC-1, stimulated ligand-dependent transactivation by wild type nuclear receptors but not mutant receptors lacking the AF2 domain. Consistent with an idea that ASC-2 is essential for the nuclear receptor function in vivo, microinjection of anti-ASC-2 antibody abrogated the ligand-dependent transactivation of retinoic acid receptor, and this repression was fully relieved by coinjection of ASC-2-expression vector. Surprisingly, ASC-2 was identical to a gene previously identified during a search for genes amplified and overexpressed in breast and other human cancers. From these results, we concluded that ASC-2 is a bona fide transcription coactivator molecule of nuclear receptors, and its altered expression may contribute to the development of cancers.

The successor representation in human reinforcement learning

Theories of reward learning in neuroscience have focused on two families of algorithms thought to capture deliberative versus habitual choice. 'Model-based' algorithms compute the value of candidate actions from scratch, whereas 'model-free' algorithms make choice more efficient but less flexible by storing pre-computed action values. We examine an intermediate algorithmic family, the successor representation, which balances flexibility and efficiency by storing partially computed action values: predictions about future events. These pre-computation strategies differ in how they update their choices following changes in a task. The successor representation's reliance on stored predictions about future states predicts a unique signature of insensitivity to changes in the task's sequence of events, but flexible adjustment following changes to rewards. We provide evidence for such differential sensitivity in two behavioural studies with humans. These results suggest that the successor representation is a computational substrate for semi-flexible choice in humans, introducing a subtler, more cognitive notion of habit.

The adolescents training and learning to avoid steroids program: preventing drug use and promoting health behaviors

BACKGROUND

Use of alcohol and other illicit drugs by adolescent male athletes is a significant problem. Participation in sports may encourage use of drugs that enhance athletic performance, especially anabolic steroids (AS). Because, to our knowledge, no other intervention has successfully altered substance abuse by athletes, we developed and assessed the efficacy of a team-centered, sex-specific education program designed to reduce adolescent athletes' intentions to use and use of AS and alcohol and other illicit drugs.

METHODS

We studied 31 high school football teams that comprised 3207 athletes in 3 successive annual cohorts (1994-1996). The intervention included interactive classroom and exercise training sessions given by peer educators and facilitated by coaches and strength trainers. Program content included discussion of sports nutrition, exercise alternatives to AS and sport supplements, and the effects of substance abuse in sports, drug refusal role-playing, and the creation of health promotion messages. Questionnaires assessing AS, the use of sport supplements and alcohol and other illicit drugs, and potential risk and protective factors were administered before and after the intervention (before and after the football season) and up to 1 year after the program.

RESULTS

At season's end, intentions to use (P<.05) and actual AS use (P<.04) were significantly lower among students who participated in the study. Although AS reduction did not achieve significance at 1 year (P<.08), intentions to use AS remained lower (P = .02). Illicit drug use (marijuana, amphetamines, and narcotics) was reduced at 1 year, whether alcohol was included (P = .04) or excluded (P = .02) from the index. Other long-term effects included fewer students reporting drinking and driving (P = .004), less sport supplement use (P = .009), and improved nutrition behaviors (P<.02).

CONCLUSIONS

Use of alcohol and other illicit drugs and associated harmful activities can be prevented with a sex-specific, team-centered education. School athletic teams provide an optimal environment in which to provide drug prevention and health promotion education.

Hepatitis B virus X protein is a transcriptional modulator that communicates with transcription factor IIB and the RNA polymerase II subunit 5

Hepatitis B virus X protein (HBx) transactivates viral and cellular genes through a wide variety of cis-elements. However, the mechanism is still obscure. Our finding that HBx directly interacts with RNA polymerase II subunit 5 (RPB5), a common subunit of RNA polymerases, implies that HBx directly modulates the function of RNA polymerase (Cheong, J. H., Yi, M., Lin, Y., and Murakami, S. (1995) EMBO J. 14, 142-150). In this context, we examined the possibility that HBx and RPB5 interact with other general transcription factors. HBx and RPB5 specifically bound to transcription factor IIB (TFIIB) in vitro, both of which were detected by either far-Western blotting or the glutathione S-transferase-resin pull-down assay. Delineation of the binding regions of these three proteins revealed that HBx, RPB5, and TFIIB each has two binding regions for the other two proteins. Co-immunoprecipitation using HepG2 cell lysates that express HBx demonstrated trimeric interaction in vivo. Some HBx substitution mutants, which had severely impaired transacting activity, exhibited reduced binding affinity with either TFIIB or RPB5 in a mutually exclusive manner, suggesting that HBx transactivation requires the interactions of both RPB5 and TFIIB. These results indicated that HBx is a novel virus modulator that facilitates transcriptional initiation by stabilizing the association between RNA polymerase and TFIIB through communication with RPB5 and TFIIB.

Major early complications following open, laparoscopic and robotic gastrectomy

BACKGROUND

Laparoscopic and robotic gastrectomy have been adopted rapidly despite lack of evidence concerning technical safety and controversy regarding additional benefits. This study aimed to compare clinically relevant complications after open, laparoscopic and robotic gastrectomy.

METHODS

This was a retrospective analysis of prospectively collected data on surgical complications in patients undergoing gastrectomy with curative intent for histologically proven adenocarcinoma between 2005 and 2010 at the Department of Surgery, Yonsei University College of Medicine in Seoul, Korea. Complications were categorized into wound infection, bleeding, anastomotic leak, obstruction, fluid collection and other.

RESULTS

In a total of 5839 patients (4542 open, 861 laparoscopic and 436 robotic gastrectomies), overall complication, reoperation and mortality rates were 10·5, 1·0 and 0·4 per cent respectively. There were no significant differences between the three groups. Ileus (P = 0·001) and intra-abdominal fluid collections (P = 0·013) were commoner after conventional open surgery. However, tumour stage was higher and more complex resections were performed in the open group. Anastomotic leak, the leading cause of death, occurred more often after a minimally invasive approach (P = 0·017).

CONCLUSION

Laparoscopic and robotic gastrectomy had overall complication and mortality rates similar to those of open surgery, but anastomotic leaks were more common with the minimally invasive techniques.

Effect of religion and religiosity on alcohol use in a college student sample

Two hundred and sixty-three alcohol using college students completed a questionnaire on their levels of alcohol use, problems with alcohol use, reasons for drinking, perceptions of control over drinking, impulsivity, venturesomeness, irrational beliefs, neuroticism, expectations of alcohol effects, depression, social norms, religious affiliation and intrinsic and extrinsic religiosity. Analyses of variance revealed that students with no religious affiliation reported significantly higher levels of drinking frequency and quantity, getting drunk, celebratory reasons for drinking and perceived drinking norms than those of either Catholic or Protestant religious affiliation, while no significant differences across groups were found for alcohol use problems. Protestants reported significantly higher levels of perceived drinking control than Catholics. Intrinsic religiosity, reflecting one's ego involvement with the tenets of one's religion, appeared to play a more important positive role over drinking behavior for Protestants than for Catholics.

Silencing mediator of retinoic acid and thyroid hormone receptors, as a novel transcriptional corepressor molecule of activating protein-1, nuclear factor-kappaB, and serum response factor

Silencing mediator of retinoic acid and thyroid hormone receptors (SMRT) is known to interact with Sin3 and recruit the histone deacetylases (HDACs) that lead to hypoacetylation of histones and transrepression of target transcription factors. Herein, we found that coexpression of SMRT significantly repressed transactivations by activating protein-1 (AP-1), nuclear factor-kappaB (NFkappaB), and serum response factor (SRF) in a dose-dependent manner, but not in the presence of trichostatin A, a specific inhibitor of HDAC. Similarly, coexpression of HDAC1 and mSin3A also showed repressive effects. Consistent with these results, the C-terminal region of SMRT directly interacted with SRF, the AP-1 components c-Jun and c-Fos, and the NFkappaB components p50 and p65, as demonstrated by the yeast and mammalian two hybrid tests as well as the glutathione S-transferase pull down assays. Thus, we concluded that SMRT serves to recruit Sin3/HDACs to SRF, NFkappaB, and AP-1 in vivo and modulate their transactivation.

Mediating mechanisms in a program to reduce intentions to use anabolic steroids and improve exercise self-efficacy and dietary behavior

This study investigated the mediating mechanisms responsible for the effects of a program designed to reduce intentions to use anabolic steroids, improve nutrition, and increase strength training self-efficacy. Fifteen of 31 high school football teams (N = 1,506 players at baseline) in Oregon and Washington were assigned to receive the intervention. The multicomponent program addressed the social influences promoting ergogenic drug use and engaging students in healthy nutrition and strength training alternative behaviors. Although the results differed across the three dependent variables, the program appeared to work by changing team norms. Unlike prevention of other drugs, changes in knowledge and perceived severity were mediators of program effects in this study.

Prevalence of psychiatric diagnoses in preterm and full-term children, adolescents and young adults: a meta-analysis

BACKGROUND

Preterm (PT) birth and low birth weight (LBW) are high-prevalence events that are associated with adverse outcomes in the longer term, with vulnerability increasing as maturity at birth decreases. Psychiatric symptomatology appears heightened in PT/LBW survivors, though there are some discordant findings from studies using questionnaire measures, particularly with respect to anxiety and depressive symptoms.

METHOD

This article synthesises findings from research using clinical psychiatric diagnostic criteria in PT/LBW individuals aged 10-25 years compared with term-born peers. Key outcomes of interest were the rates of individuals receiving any psychiatric diagnosis and the number of diagnoses of anxiety or depressive disorders.

RESULTS

A literature search for studies reporting prevalence of 'any diagnosis' yielded five studies that met inclusion criteria, with a total of 565 PT/LBW and 533 control individuals. Also, five studies were found that reported rates of anxiety/depression (692 PT/LBW and 605 control individuals). The risk of these outcomes was increased for PT/LBW individuals compared with controls [any diagnosis: odds ratio (OR) 3.66, 95% confidence interval (CI) 2.57-5.21; anxiety or depressive disorder: OR 2.86, 95% CI 1.73-4.73].

CONCLUSIONS

The studies reviewed here indicate that, in addition to monitoring and management of medical and cognitive sequelae, the psychological well-being of PT/LBW individuals should be a key part of ongoing care.

ATF-2 and C/EBPalpha can form a heterodimeric DNA binding complex in vitro. Functional implications for transcriptional regulation

We screened an expression cDNA library with a radiolabeled C/EBPalpha fusion protein and isolated three independent cDNAs encoding ATF-2, a bZIP protein that binds cAMP response elements (CRE). This interaction requires the respective bZIP domains, which form a typical bZIP heterodimer with altered DNA binding selectivity. C/EBPalpha and ATF-2 homodimers bind CRE sites, but ATF-2:C/EBPalpha heterodimers do not. Heterodimers bind an asymmetric sequence composed of one consensus half-site for each monomer, and may thus have a unique regulatory function. As predicted, co-transfection of ATF-2 with C/EBPalpha results in decreased activation of transcription driven from consensus C/EBP-binding sites. In contrast, C/EBPalpha and ATF-2 function cooperatively to activate transcription driven by the asymmetric sequence. Both factors are expressed in liver, where immunoprecipitation experiments show that ATF-2 co-precipitates with C/EBPalpha. These results are consistent with the interpretation that C/EBPalpha and ATF-2 can associate in vivo. Moreover, the formation of ATF-2:C/EBPbeta heterodimers suggests that cross-family dimerization with ATF-2 may be a general property for C/EBP family proteins.

Ca2+/calmodulin-dependent protein kinase IV stimulates nuclear factor-kappa B transactivation via phosphorylation of the p65 subunit

Calmodulin-dependent protein kinase IV (CaMKIV) is a key mediator of Ca(2+)-induced gene expression. In this study, CaMKIV was found to directly associate with and phosphorylate the nuclear factor-kappaB (NFkappaB) component p65 both in vitro and in vivo. The phosphorylation of p65 by CaMKIV resulted in recruitment of transcription coactivator cAMP-response element-binding protein-binding protein and concomitant release of corepressor silencing mediator for retinoid and thyroid hormone receptors, as demonstrated by the glutathione S-transferase pull down and mammalian two hybrid assays. In addition, cotransfection of CaMKIV resulted in cytosolic translocation of the silencing mediator for retinoid and thyroid hormone receptors. Consistent with these results, cotransfected CaMKIV dramatically stimulated the NFkappaB transactivation in mammalian cells. From these results, NFkappaB is suggested to be a novel downstream effector molecule of CaMKIV.

A QTL located on chromosome 4A associated with dormancy in white- and red-grained wheats of diverse origin

Improved resistance to preharvest sprouting in modern bread wheat (Triticum aestivum. L.) can be achieved via the introgression of grain dormancy and would reduce both the incidence and severity of damage due to unfavourable weather at harvest. The dormancy phenotype is strongly influenced by environmental factors making selection difficult and time consuming and this trait an obvious candidate for marker assisted selection. A highly significant Quantitative Trait Locus (QTL) associated with grain dormancy and located on chromosome 4A was identified in three bread wheat genotypes, two white- and one red-grained, of diverse origin. Flanking SSR markers on either side of the putative dormancy gene were identified and validated in an additional population involving one of the dormant genotypes. Genotypes containing the 4A QTL varied in dormancy phenotype from dormant to intermediate dormant. Based on a comparison between dormant red- and white-grained genotypes, together with a white-grained mutant derived from the red-grained genotype, it is concluded that the 4A QTL is a critical component of dormancy; associated with at least an intermediate dormancy on its own and a dormant phenotype when combined with the R gene in the red-grained genotype and as yet unidentified gene(s) in the white-grained genotypes. These additional genes appeared to be different in AUS1408 and SW95-50213.

Intraoperative tumor localization using laparoscopic ultrasonography in laparoscopic-assisted gastrectomy

BACKGROUND

During laparoscopic-assisted gastrectomy, it is impossible to identify early gastric cancer (EGC) lesions; therefore, a precise localization technique is needed. In this study, we used laparoscopic ultrasonography (LUS) after endoscopic clipping as a method of localizing EGC and evaluated the effectiveness of this method.

METHODS

A prospective study of 17 patients who had undergone laparoscopic-assisted gastrectomy was performed. Three endoscopic clips were applied just proximal to the tumor during the preoperative endoscopy. The applied clips were detected from the serosal side of the stomach using LUS. The serosal surface of the lesion was marked with dye.

RESULTS

In all patients, endoscopic clips were applied proximal to the lesion without complications, and the applied clips were confirmed by plain abdominal radiography. The clips were successfully detected by LUS in all patients. In the resected specimen, the serosal surface, marked with dye, was always just above the clips in the anterior wall or on the anterior wall opposite the clips applied in the posterior wall. The mean detection time was 4.7 min (range, 2-8). With this procedure, two patients underwent total gastrectomy and 15 patients underwent distal subtotal gastrectomy with gastroduodenostomy or gastrojejunostomy. Histological examination confirmed that the resection margins were tumor free in all patients. There was no operative morbidity related to the LUS procedure.

CONCLUSIONS

Using LUS to detect endoscopic clips is an easy, safe, and accurate method to localize EGC lesions in laparoscopic-assisted gastrectomy.

Impact of pretreatment thrombocytosis on blood-borne metastasis and prognosis of gastric cancer

BACKGROUND

Thrombocytosis has been associated with malignancies and poor prognostic implications in cancer patients. In the present study the prognostic significance of pretreatment platelet (PLT) level was assessed with regard to recurrence and survival in patients with primary gastric adenocarcinoma.

METHODS

The authors reviewed the prospective data of 1593 gastric cancer patients who received curative gastrectomy with extended lymphadenectomy. The correlations of PLT level with recurrence and overall survival were evaluated by both univariate and multivariate analyses.

RESULTS

Thrombocytosis (≥ 40 × 10(4)/ μL), present in 6.4% of the patients prior to curative surgery, was more frequently associated with advanced T and N classification, larger tumor size, anemia, and leukocytosis (p < 0.05). In patients with pretreatment thrombocytosis compared to those without it, five-year survival rate was worse (56.9% vs. 65.5%; p = 0.043), and recurrence rate was higher mainly due to the frequent hematogenous spread (51.0% vs. 34.5%; p < 0.001). Furthermore, risk of blood-borne metastasis was almost three-fold higher in patients with pretreatment thrombocytosis (Odds ratio 2.83 [95% CI 1.67-4.77], p < 0.001).

CONCLUSIONS

Pretreatment thrombocytosis correlated significantly with poor prognosis and can be used as an independent predictor of recurrence by blood-borne metastasis in gastric cancer.

Role of serotonin in the anticonvulsant effect of fluoxetine in genetically epilepsy-prone rats

This study was designed to demonstrate a role of serotonin in the anticonvulsant effect of fluoxetine, a serotonin reuptake inhibitor, in genetically epilepsy-prone rats. When varied doses of 5-hydroxytryptophan (12.5, 25, 50 mg/kg) were administered i.p. along with a fixed dose of fluoxetine (15 mg/kg) to severe seizure genetically epilepsy-prone rats, the severity of audiogenic seizures was decreased dose-dependently, and the combination treatment also produced a marked potentiation of the anticonvulsant effect when compared with administration of either drug alone. Pretreatment of severe seizure genetically epilepsy-prone rats with p-chlorophenylalanine depleted brain serotonin and reduced the anticonvulsant effectiveness of fluoxetine. By using intracerebral microdialysis, the depletion of serotonin after p-chlorophenylalanine treatment was confirmed by measuring thalamic extracellular serotonin and 5-hydroxyindoleacetic acid concentrations during basal release and in response to a challenge dose of fluoxetine. We concluded that serotonergic transmission may be involved in the anticonvulsant effect of fluoxetine in severe seizure genetically epilepsy-prone rats.

The Liverpool uveal melanoma liver metastases pathway: outcome following liver resection

AIM

To determine the outcome of patients that underwent liver resection for metastases from uveal melanoma.

METHODS

Over a 9-year period, patients referred with uveal melanoma metastases were included. Following treatment of primary uveal melanoma, high-risk patients were offered to be enrolled into a 6-monthly non-contrast liver magnetic resonance imaging (MRI) surveillance. Following detection of liver metastases, patients were staged with a contrast-enhanced (Primovist(®)) liver MRI, computer tomography (CT) of the thorax and staging laparoscopy.

RESULTS

155 patients were referred with uveal melanoma liver metastases, of which 17 (11.0%) patients had liver resection and one patient was treated with percutaneous radio-frequency ablation. The majority of patients undergoing liver resection were treated with multiple metastectomies (n = 8) and three patients had major liver resections. The overall median survival for patients treated with surgery/ablation was 27 (14-90) months, and this was significantly better compared to patients treated palliatively [median = 8(1-30) months, P < 0.001]. Following surgery, 11 patients had recurrent disease [median = 13(6-36) months]. Patients who had undergone a major liver resection had a significantly poorer disease-free survival (P = 0.037).

CONCLUSIONS

Patients who can undergo surgical resection for metastatic uveal melanoma have a more favorable survival compared to those who do not.

Anticonvulsant properties of D-20443 in genetically epilepsy-prone rats: prediction of clinical response

D-20443 is an experimental antiepileptic drug. Its mechanism of antiepileptic action is unknown. We evaluated the anticonvulsant effectiveness of D-20443 against sound-induced seizures in genetically epilepsy-prone rats (GEPRs). This compound produced anticonvulsant effects against sound-induced seizures in moderate seizure GEPRs (GEPR-3s) at significantly lower doses than in severe seizure GEPRs (GEPR-9s). Based on these data and on the responses of GEPRs to other antiepileptic drugs, we predict that D-20443 will be a broad spectrum antiepileptic agent in humans. That is, we predict that D-20443 will suppress both tonic/clonic and absence seizures in humans.

Association between phthalates and externalizing behaviors and cortical thickness in children with attention deficit hyperactivity disorder

BACKGROUND

Previous studies have implicated the relationship between environmental phthalate exposure and attention deficit hyperactivity disorder (ADHD) symptoms of childhood, but no studies have been conducted in children who have a confirmed diagnosis of ADHD obtained through meticulous diagnostic testing. We aimed to determine whether phthalate metabolites in urine would be higher in children with ADHD than in those without ADHD and would correlate with symptom severity and cortical thickness in ADHD children.

METHOD

A cross-sectional examination of urine phthalate metabolite concentrations was performed; scores for ADHD symptoms, externalizing problems, and continuous performance tests were obtained from 180 children with ADHD, and brain-imaging data were obtained from 115 participants. For the control group, children without ADHD (N = 438) were recruited. Correlations between phthalate metabolite concentrations and clinical measures and brain cortical thickness were investigated.

RESULTS

Concentrations of phthalate metabolites, particularly the di(2-ethylhexyl) phthalate (DEHP) metabolite, were significantly higher in boys with ADHD than in boys without ADHD. Concentrations of the di-n-butyl phthalate (DBP) metabolite were significantly higher in the combined or hyperactive-impulsive subtypes compared to the inattentive subtype, and the metabolite was positively correlated with the severity of externalizing symptoms. Concentrations of the DEHP metabolite were negatively correlated with cortical thickness in the right middle and superior temporal gyri.

CONCLUSIONS

The results of this study suggest an association between phthalate concentrations and both the diagnosis and symptom severity of ADHD. Imaging findings suggest a negative impact of phthalates on regional cortical maturation in children with ADHD.

Factors influencing operation time of laparoscopy-assisted distal subtotal gastrectomy: Analysis of consecutive 100 initial cases

AIMS

There is little information on patient selection criteria for laparoscopy-assisted distal gastrectomy (LADG) that would facilitate a successful initial experience for a surgeon new to the procedure. This study aimed to establish patient selection criteria that will allow increased proficiency and shorter operation times for the LADG procedure.

METHOD

One hundred LADG with lymphadenectomy and no other combined procedures were consecutively performed by one surgeon. These 100 consecutive LADG procedures were analyzed retrospectively from a prospectively designed computer database. Uni- and multivariate analyses were performed to identify factors influencing operation time.

RESULTS

According to univariate analysis, operation time was influenced by sex, BMI, surgical experience, and tumor location, whereas multivariate analysis indicated that operation time was significantly influenced only by BMI and surgical experience. The same analyses of only the first 50 cases showed that sex, BMI, surgical experience, and tumor location were independently associated with operation time. As BMI increased, so did operation time, whereas operation time decreased with increasing surgical experience.

CONCLUSION

This study suggests that surgeons who have limited experience with this advanced procedure may shorten operation time by considering patient and tumor characteristics in their early attempts at LADG. With a shortened operation time, surgeon with limited experience may become proficient to LADG rapidly.

Transactivation of human hepatitis B virus X protein, HBx, operates through a mechanism distinct from protein kinase C and okadaic acid activation pathways

Human hepatitis B virus (HBV) X protein, HBx, transactivates virus and host genes through a wide variety of cis-elements. Expression of HBx is controlled by HBV enhancer 1 (Enh1). Both Enh1 and the core sequence of Enh1, which consists of an AP-1 related site (cFAP1) and a C stretch, respond to HBx and a phorbol ester (TPA). Biochemical pathways of the responses to HBx and TPA are still controversial. We therefore asked whether HBx and TPA stimulate Enh1 core activity through a common process. Protein kinase C (PKC) inhibitors, H-7 and staurosporin, did not inhibit HBx transactivation at concentrations sufficient to abolish the TPA effects in HepG2 cells. Although HBx transactivation synergized independently with TPA or a phosphoprotein phosphatase inhibitor, okadaic acid (OA), the PKC inhibitors eliminated only the TPA contribution. HBx transactivation required both the cFAP1 and the C stretch of the Enh1 core region; however, mutations in either or both of the two cis-elements demonstrated that TPA augmentation required only cFAP1. These results imply that HBx transactivation operates through a mechanism distinct from the PKC and OA activation pathways.

Activating transcription factor-2 regulates phosphoenolpyruvate carboxykinase transcription through a stress-inducible mitogen-activated protein kinase pathway

Several protein-nucleic acid complexes are observed when nuclear extracts from hepatoma cells are assayed for binding to the cAMP response element found in the phosphoenolpyruvate carboxykinase-cytosolic (PEPCK-C) promoter. Although cAMP response element-binding protein and CCAAT/enhancer binding proteins alpha and beta have been identified as liver factors that bind this motif, an uncharacterized, slower migrating complex was also observed. We identify activating transcription factor-2 (ATF-2) as the factor in this complex and show that ATF-2 stimulates expression from the PEPCK-C promoter. ATF-2 is a basic-leucine zipper transcription factor and a target for stress-activated protein kinases. We demonstrate that p38beta mitogen-activated protein (MAP) kinase augments ATF-2 transactivation activity on the PEPCK-C promoter, which is consistent with the interpretation that PEPCK-C promoter activity is maintained under stress through a p38 MAP kinase dependent pathway. In this regard, we show that treatment with sodium arsenite, a known activator of p38 MAP kinases, also stimulates expression from the PEPCK promoter. These results show that ATF-2 can stimulate transcription of the PEPCK-C promoter and support a role for stress inducible kinases in the maintenance of PEPCK-C expression.

Predictive factors for recurrence and clinical outcomes in patients with chronic subdural hematoma

OBJECTIVE Chronic subdural hematoma (CSDH) is a common type of intracranial hemorrhage in elderly patients. Many studies have suggested various factors that may be associated with the recurrence of CSDH. However, the results are inconsistent. The purpose of this study was to determine the associations among patient factors, recurrence, and clinical outcomes of CSDH after bur hole surgery performed during an 11-year period at twin hospitals. METHODS Kaplan-Meier analysis was performed to evaluate the risk factors for CSDH recurrence. Univariate and multivariate Cox proportional hazards regression analyses were used to calculate hazard ratios with 95% CIs for CSDH recurrence based on many variables. One-way repeated-measures ANOVA was used to assess the differences in the mean modified Rankin Scale score between categories for each risk factor during each admission and at the last follow-up. RESULTS This study was a retrospective analysis of 756 consecutive patients with CSDH who underwent bur hole surgery at the Hanyang University Medical Center (Seoul and Guri) between January 1, 2004, and December 31, 2014. During the 6-month follow-up, 104 patients (13.8%) with recurrence after surgery for CSDH were identified. Independent risk factors for recurrence were as follows: age > 75 years (HR 1.72, 95% CI 1.03-2.88; p = 0.039), obesity (body mass index ≥ 25.0 kg/m²), and a bilateral operation. CONCLUSIONS This study determined the risk factors for recurrence of CSDH and their effects on outcomes. Further studies are needed to account for these observations and to determine their underlying mechanisms.

Comparison of Complications Following Cranioplasty Using a Sterilized Autologous Bone Flap or Polymethyl Methacrylate

Objective

The aims of current study are to compare complications following cranioplasty (CP) using either sterilized autologous bone or polymethyl methacrylate (PMMA), and to identify the risk factors for two of the most common complications: bone flap resorption (BFR) and surgical site infection (SSI).

Methods

Between January 2004 and December 2013, 127 patients underwent CP and were followed at least 12 months. Variables, including sex, age, initial diagnosis, time interval between decompressive craniectomy (DC) and CP, operation time, size of bone flap, and presence of ventriculo-peritoneal shunt, were analyzed to identify the risk factors for BFR and SSI.

Results

A total of 97 (76.4%) patients underwent CP using PMMA (Group I) and 30 (23.6%) underwent CP using autologous bone (Group II). SSI occurred in 8 (8.2%) patients in Group I, and in 2 (6.7%) in Group II; there was no statistically significant difference between the groups (p=1.00). No statistically significant risk factors for SSI were found in either group. In Group I, there was no reported case of BFR. In Group II patients, BFR developed in 18 (60.0%) patients at the time of CP (Type 1 BFR), and at 12-month follow up (Type 2 BFR) in 4 (13.3%) patients. No statistically significant risk factors for BFR were found in Group II.

Conclusion

CP using sterilized autologous bone result in a significant rate of BFR. PMMA, however, is a safe alloplastic material for CP, as it has low complication rate.