Systematic review with meta-analysis: placebo rates in induction and maintenance trials of Crohn's disease.

BACKGROUND: Minimising placebo response is essential for drug development. AIM: To conduct a meta-analysis to determine placebo response and remission rates in trials and identify the factors affecting these rates. METHODS: MEDLINE, EMBASE and CENTRAL were searched from inception to April 2014 for placebo-controlled trials of pharmacological interventions for Crohn's disease. Placebo response and remission rates for induction and maintenance trials were pooled by random-effects and mixed-effects meta-regression models to evaluate effects of study-level characteristics on these rates. RESULTS: In 100 studies containing 67 induction and 40 maintenance phases and 7638 participants, pooled placebo remission and response rates for induction trials were 18% [95% confidence interval (CI) 16-21%] and 28% (95% CI 24-32%), respectively. Corresponding values for maintenance trials were 32% (95% CI 25-39%) and 26% (95% CI 19-35%), respectively. For remission, trials enrolling patients with more severe disease activity, longer disease duration and more study centres were associated with lower placebo rates, whereas more study visits and longer study duration was associated with higher placebo rates. For response, findings were opposite such that trials enrolling patients with less severe disease activity and longer study duration were associated with lower placebo rates. Placebo rates varied by drug class and route of administration, with the highest placebo response rates observed for biologics. CONCLUSIONS: Placebo rates vary according to whether trials are designed for induction or maintenance and the factors influencing them differ for the endpoints of remission and response. These findings have important implications for clinical trial design in Crohn's disease.

Clinical risk factors of colorectal cancer in patients with serrated polyposis syndrome: a multicentre cohort analysis.

OBJECTIVE: Serrated polyposis syndrome (SPS) is accompanied by an increased risk of colorectal cancer (CRC). Patients fulfilling the clinical criteria, as defined by the WHO, have a wide variation in CRC risk. We aimed to assess risk factors for CRC in a large cohort of patients with SPS and to evaluate the risk of CRC during surveillance. DESIGN: In this retrospective cohort analysis, all patients with SPS from seven centres in the Netherlands and two in the UK were enrolled. WHO criteria were used to diagnose SPS. Patients who only fulfilled WHO criterion-2, with IBD and/or a known hereditary CRC syndrome were excluded. RESULTS: In total, 434 patients with SPS were included for analysis; 127 (29.3%) were diagnosed with CRC. In a per-patient analysis ≥1 serrated polyp (SP) with dysplasia (OR 2.07; 95% CI 1.28 to 3.33), ≥1 advanced adenoma (OR 2.30; 95% CI 1.47 to 3.67) and the fulfilment of both WHO criteria 1 and 3 (OR 1.60; 95% CI 1.04 to 2.51) were associated with CRC, while a history of smoking was inversely associated with CRC (OR 0.36; 95% CI 0.23 to 0.56). Overall, 260 patients underwent surveillance after clearing of all relevant lesions, during which two patients were diagnosed with CRC, corresponding to 1.9 events/1000 person-years surveillance (95% CI 0.3 to 6.4). CONCLUSION: The presence of SPs containing dysplasia, advanced adenomas and/or combined WHO criteria 1 and 3 phenotype is associated with CRC in patients with SPS. Patients with a history of smoking show a lower risk of CRC, possibly due to a different pathogenesis of disease. The risk of developing CRC during surveillance is lower than previously reported in literature, which may reflect a more mature multicentre cohort with less selection bias.

Alcohol resistance in Drosophila is modulated by the Toll innate immune pathway.

A growing body of evidence has shown that alcohol alters the activity of the innate immune system and that changes in innate immune system activity can influence alcohol-related behaviors. Here, we show that the Toll innate immune signaling pathway modulates the level of alcohol resistance in Drosophila. In humans, a low level of response to alcohol is correlated with increased risk of developing an alcohol use disorder. The Toll signaling pathway was originally discovered in, and has been extensively studied in Drosophila. The Toll pathway is a major regulator of innate immunity in Drosophila, and mammalian Toll-like receptor signaling has been implicated in alcohol responses. Here, we use Drosophila-specific genetic tools to test eight genes in the Toll signaling pathway for effects on the level of response to ethanol. We show that increasing the activity of the pathway increases ethanol resistance whereas decreasing the pathway activity reduces ethanol resistance. Furthermore, we show that gene products known to be outputs of innate immune signaling are rapidly induced following ethanol exposure. The interaction between the Toll signaling pathway and ethanol is rooted in the natural history of Drosophila melanogaster.

ARHI (DIRAS3)-mediated autophagy-associated cell death enhances chemosensitivity to cisplatin in ovarian cancer cell lines and xenografts.

Autophagy can sustain or kill tumor cells depending upon the context. The mechanism of autophagy-associated cell death has not been well elucidated and autophagy has enhanced or inhibited sensitivity of cancer cells to cytotoxic chemotherapy in different models. ARHI (DIRAS3), an imprinted tumor suppressor gene, is downregulated in 60% of ovarian cancers. In cell culture, re-expression of ARHI induces autophagy and ovarian cancer cell death within 72 h. In xenografts, re-expression of ARHI arrests cell growth and induces autophagy, but does not kill engrafted cancer cells. When ARHI levels are reduced after 6 weeks, dormancy is broken and xenografts grow promptly. In this study, ARHI-induced ovarian cancer cell death in culture has been found to depend upon autophagy and has been linked to G1 cell-cycle arrest, enhanced reactive oxygen species (ROS) activity, RIP1/RIP3 activation and necrosis. Re-expression of ARHI enhanced the cytotoxic effect of cisplatin in cell culture, increasing caspase-3 activation and PARP cleavage by inhibiting ERK and HER2 activity and downregulating XIAP and Bcl-2. In xenografts, treatment with cisplatin significantly slowed the outgrowth of dormant autophagic cells after reduction of ARHI, but the addition of chloroquine did not further inhibit xenograft outgrowth. Taken together, we have found that autophagy-associated cancer cell death and autophagy-enhanced sensitivity to cisplatin depend upon different mechanisms and that dormant, autophagic cancer cells are still vulnerable to cisplatin-based chemotherapy.

CREB regulation of BK channel gene expression underlies rapid drug tolerance.

Pharmacodynamic tolerance is believed to involve homeostatic mechanisms initiated to restore normal neural function. Drosophila exposed to a sedating dose of an organic solvent, such as benzyl alcohol or ethanol, acquire tolerance to subsequent sedation by that solvent. The slo gene encodes BK-type Ca(2+)-activated K(+) channels and has been linked to alcohol- and organic solvent-induced behavioral tolerance in mice, Caenorhabditis elegans (C. elegans) and Drosophila. The cyclic AMP response element-binding (CREB) proteins are transcription factors that have been mechanistically linked to some behavioral changes associated with drug addiction. Here, we show that benzyl alcohol sedation alters expression of both dCREB-A and dCREB2-b genes to increase production of positively acting CREB isoforms and to reduce expression of negatively acting CREB variants. Using a CREB-responsive reporter gene, we show that benzyl alcohol sedation increases CREB-mediated transcription. Chromatin immunoprecipitation assays show that the binding of dCREB2, with a phosphorylated kinase-inducible domain, increases immediately after benzyl alcohol sedation within the slo promoter region. Most importantly, we show that a loss-of-function allele of dCREB2 eliminates drug-induced upregulation of slo expression and the production of benzyl alcohol tolerance. This unambiguously links dCREB2 transcription factors to these two benzyl alcohol-induced phenotypes. These findings suggest that CREB positively regulates the expression of slo-encoded BK-type Ca(2+)-activated K(+) channels and that this gives rise to behavioral tolerance to benzyl alcohol sedation.

The impact of Internet use for weight loss.

With rising rates of obesity and obesity-related health problems, finding additional means to help reduce obesity is critical. This review examined the impact of the Internet as a medium to deliver weight loss programs. Specifically, the review examined the public's interest, the availability and the known efficacy of Internet-based weight loss programs. Findings showed that the general public is turning to the Internet for diet and fitness information and has reported that information they found online has impacted their behaviour. Little is known about who is interested in using the Internet for weight loss and what their experiences have been. The programs most readily available to the general consumer tend to vary widely in quality, with few efficacy studies. However, researchers have shown that efficacious programs have been delivered via the Internet. Successful online programs included a structured approach to modifying energy balance, the use of cognitive-behavioural strategies such as self-monitoring, and individualized feedback and support. Implications include developing strategies to increase distribution of programs with known efficacy, determining the applicability of effective programs for diverse audiences, conducting media literacy education for the general public, and continued research into understanding who may be best served by online weight loss programming.

Tissue-specific alternative splicing of BK channel transcripts in Drosophila.

BK-type calcium-activated potassium channels are large conductance channels that respond to changes in intracellular calcium and membrane potential. These channels are used in a wide variety of cell types and have recently been linked to drug sensitivity and tolerance. In both Drosophila and mammals, BK channels are encoded by the slowpoke gene. The Drosophila slowpoke gene includes 14 alternative exons distributed among five sites of alternative splicing. Presumably, the purpose of alternative processing is to provide transcripts tailored to the needs of the cell. The slowpoke gene is expressed in nervous, muscle and epithelial tissues. To determine whether splicing is controlled in a tissue- and/or developmental-specific manner, we built tissue- and developmental-specific cDNA libraries that preserved the relative frequency of various slowpoke splice variants. These libraries were screened by colony hybridization using alternative exon-specific DNA probes to document the frequency of individual alternative exons in different developmental stages and distinct tissue types. We demonstrate that slowpoke transcripts undergo tissue- and developmental-specific splicing in Drosophila and some exons are diagnostic for specific tissues.

The slowpoke gene is necessary for rapid ethanol tolerance in Drosophila.

BACKGROUND: Ethanol is one of the most commonly used drugs in the world. We are interested in the compensatory mechanisms used by the nervous system to counter the effects of ethanol intoxication. Recently, the slowpoke BK-type calcium-activated potassium channel gene has been shown to be involved in ethanol sensitivity in Caenorhabditis elegans and in rapid tolerance to the anesthetic benzyl alcohol in Drosophila. METHODS: We used Drosophila mutants to investigate the role of slowpoke in rapid tolerance to sedation with ethanol vapor. Rapid tolerance was defined as a reduction in the sedative phase caused by a single previous sedation. The ethanol and water contents of flies were measured to determine if pharmacodynamic changes could account for tolerance. RESULTS: A saturated ethanol air stream caused sedation in <20 min and resulted in rapid tolerance that was apparent 4 hr after sedation. Two independently isolated null mutations in the slowpoke gene eliminated the capacity for tolerance. In addition, a third mutation that blocked expression specifically in the nervous system also blocked rapid tolerance. Water measurements showed that both ethanol and mock sedation caused equivalent dehydration. Furthermore, a single prior exposure to ethanol did not cause a change in the ethanol clearance rate. CONCLUSIONS: Rapid tolerance, measured as a reduction in the duration of sedation, is a pharmacokinetic response to ethanol that does not occur without slowpoke expression in the nervous system in Drosophila. The slowpoke channel must be involved in triggering or producing a homeostatic mechanism that opposes the sedative effects of ethanol.

Induction of p53-regulated genes and tumor regression in lung cancer patients after intratumoral delivery of adenoviral p53 (INGN 201) and radiation therapy.

PURPOSE: We designed a prospective single arm Phase II study to evaluate the feasibility and mechanisms of apoptosis induction after Ad-p53 (INGN 201) gene transfer and radiation therapy in patients with non-small cell lung cancer. EXPERIMENTAL DESIGN: Nineteen patients with nonmetastatic non-small cell lung cancer who were not eligible for chemoradiation or surgery were treated as outpatients with radiation therapy to 60 Gy over 6 weeks in conjunction with three intratumoral injections of Ad-p53 (INGN 201) on days 1, 18, and 32. RESULTS: Seventeen of 19 patients completed all planned radiation and Ad-p53 (INGN 201) gene therapy as outpatients. The most common adverse events were grade 1 or 2 fevers (79%) and chills (53%). Three months after completion of therapy, pathologic biopsies of the primary tumor revealed no viable tumor (12 of 19 patients, 63%), viable tumor (3 of 19 patients, 16%), and not assessed (4 of 19 patients, 21%). Computed tomography and bronchoscopic findings at the primary injected tumor revealed complete response (1 of 19 patients, 5%), partial response (11 of 19 patients, 58%), stable disease (3 of 19 patients, 16%), progressive disease (2 of 19 patients, 11%), and not evaluable (2 of 19 patients, 11%). Quantitative reverse transcription-PCR analysis of the four p53 related genes [p21 (CDKN1A), FAS, BAK, and MDM2] revealed that Bak expression was increased significantly 24 h after Ad-p53 (INGN 201) injection and levels of CDKN1A and MDM2 expression were increased over the course of treatment. CONCLUSIONS: Intratumoral injection of Ad-p53 (INGN 201) in combination with radiation therapy is well tolerated and demonstrates evidence of tumor regression at the primary injected tumor. Serial biopsies of the tumor suggest that BAK gene expression is most closely related to Ad-p53 (INGN 201) gene transfer.

Eversion carotid endarterectomy.

BACKGROUND: Eversion carotid endarterectomy (ECEA) is a technique that obviates the need for traditional longitudinal arteriotomy and patch closure, with low stroke and restenosis rates. The aim of the present study was to report an Australian experience and technique of ECEA. METHODS: All patients who underwent ECEA by the investigating surgeons between October 1997 and July 2000 were followed up clinically and with duplex ultrasound. The technique of ECEA is described. RESULTS: One hundred and fifty-two ECEA were performed, 13 combined with coronary artery bypass grafting (CABG). The combined perioperative stroke and death rate was 2%; 0.65% excluding CABG combined cases. This compares with 2.9% for standard carotid endarterectomy throughout Victoria. Significant restenosis occurred in 2.6% after a mean follow up of 21.7 months. CONCLUSION: ECEA is a simple and safe alternative to standard carotid endarterectomy.

Tandem lesions of the carotid circulation: combined extracranial endarterectomy and intracranial transluminal angioplasty.

A case series is presented demonstrating a unique approach to the treatment of tandem atherosclerotic lesions of the internal carotid artery. Between 1994 and 1999 eight patients with tandem lesions of the internal carotid artery were treated by combined carotid endarterectomy for the proximal lesion and intraoperative angioplasty of the distal intracranial lesion via the carotid arteriotomy. The success and complication rates were evaluated. A 100% technical success rate was achieved with one post procedural complication by ipsilateral stroke within 24 h. The advantages of this technique include the treatment of tandem lesions by the one procedure, improved transluminal access to the intracranial lesion and the ability to reduce the risk of embolism by flow control during balloon inflation.

Evolution and divergence of sodium channel genes in vertebrates.

Invertebrate species possess one or two Na+ channel genes, yet there are 10 in mammals. When did this explosive growth come about during vertebrate evolution? All mammalian Na+ channel genes reside on four chromosomes. It has been suggested that this came about by multiple duplications of an ancestral chromosome with a single Na+ channel gene followed by tandem duplications of Na+ channel genes on some of these chromosomes. Because a large-scale expansion of the vertebrate genome likely occurred before the divergence of teleosts and tetrapods, we tested this hypothesis by cloning Na+ channel genes in a teleost fish. Using an approach designed to clone all of the Na+ channel genes in a genome, we found six Na+ channel genes. Phylogenetic comparisons show that each teleost gene is orthologous to a Na+ channel gene or gene cluster on a different mammalian chromosome, supporting the hypothesis that four Na+ channel genes were present in the ancestors of teleosts and tetrapods. Further duplications occurred independently in the teleost and tetrapod lineages, with a greater number of duplications in tetrapods. This pattern has implications for the evolution of function and specialization of Na+ channel genes in vertebrates. Sodium channel genes also are linked to homeobox (Hox) gene clusters in mammals. Using our phylogeny of Na+ channel genes to independently test between two models of Hox gene evolution, we support the hypothesis that Hox gene clusters evolved as (AB) (CD) rather than [D[A(BC)]].

Importance of health education research to health education.

OBJECTIVE: To focus on the benefits and importance of research to the practice of health education. METHODS: The paper discussed the potential of quality research as well as the barriers that keep health educators from using, applying, and sharing their work. RESULTS: The basic challenges health educators face in translating their research into practice relate to: becoming well-versed in the science base and previous lessons learned; collaborating effectively; and passing on knowledge by mentoring. CONCLUSIONS: To move forward, health educators need to organize their knowledge and make it accessible. This includes explicit and tacit knowledge, work in progress, and a coordinated research agenda. Finally, health educators need to be flexible so they can enable future research needs.

Review of aortoiliac aneurysms with spontaneous large vein fistula.

BACKGROUND: Arteriovenous fistula is a rare complication of aortoiliac aneurysmal disease, accounting for less than 2% of clinical presentations. METHODS: In addition to the 191 cases reviewed in the literature, an additional 14 cases seen at Royal Melbourne Hospital over the last 22 years are presented to illustrate the challenges in the diagnosis of this condition. CONCLUSION: An increase in awareness may lead to better management of these patients.

Online research to guide knowledge management planning.

The current paper describes the process and results of an effort to find a way to effectively manage and diffuse prevention knowledge. This study shows the role that today's communication technologies can play in ensuring collaboration and participation in both the design and use of a knowledge management system (KMS) for prevention research, practice and policy. In the context of this study, 'prevention research' includes primary through tertiary prevention efforts consistent with general applied public health research in the US. An online Delphi study was used to engage a set of prevention research constituencies in the design of a mechanism to enhance the potential for effective technology transfer. A three-round Delphi was conducted with 58 stakeholders and key informants involved in prevention: government-level policy makers, researchers and front-line practitioners. The study resulted in consensus on 34 functions and 32 output/content elements of a proposed web-based KMS called PreventionEffects.net. The paper also describes the implications of both the processes of development and the benefits of the proposed system for those interested in prevention.

Treatment of renovascular disease with percutaneous stent insertion: long-term outcomes.

Renal artery stenosis is a common, progressive cause of hypertension and renal impairment, and is frequently treated with percutaneous transluminal dilatation and stenting. The outcome of this procedure is still being evaluated. The records of 198 consecutive patients who had stents inserted at the Royal Melbourne Hospital were analysed retrospectively, and adequate follow-up information on 148 (75%), in whom a total of 182 renal arteries had been treated was obtained. Technical success was achieved in 144 patients (97%). Complications occurred in 19 patients (13.3%), with major complications occurring in 10 (7.0%) and one death occurring in relation to the procedure. A fall in average systolic blood pressure of 13.2 mmHg (12.1-14.3 mmHg) was seen and a fall in diastolic blood pressure of 10.1 mmHg (9.3-10.9 mmHg), without an increase in the number of antihypertensive drugs used. Renal function remained stable in the majority of patients, particularly those who had minimal baseline renal impairment. Restenosis was common after 6 months, occurring eventually in 29% of screened patients, but was not shown to affect clinical outcomes. Insertion of renal artery stents is a safe and effective treatment for renal artery stenosis.

Novel translational model for breast cancer chemoprevention study: accrual to a presurgical intervention with tamoxifen and N-[4-hydroxyphenyl] retinamide.

Surrogate end point biomarkers for risk assessment and efficacy of potential chemopreventive agents are needed to improve the efficiency and reduce the cost of chemoprevention trials. It is imperative to develop the best clinical breast model for translational surrogate end point biomarker studies, especially with respect to accrual feasibility. We have initiated a prospective study to develop biomarkers for tamoxifen and N-[4-hydroxyphenyl] retinamide by administering either a placebo or both drugs for 2-4 weeks to women with ductal carcinoma in situ or early invasive cancers in the interval between the initial diagnostic core biopsy and definitive surgery. The principle end point is pretreatment versus posttreatment tumor levels of Ki-67; a number of other exploratory markers will also be examined. The planned target sample size is 100 patients. Between February 1997 and February 2000, 4514 women who had either an abnormal mammogram or a diagnosed breast cancer were screened for the study. Of these 4514 screened patients, 52 (1%) were registered on the study. Major factors of nonparticipation in the remaining 4462 women were as follows: (a) no evidence of malignancy (2081 patients; 46%); (b) ineligible per protocol criteria (575 patients; 13%); (c) preoperative chemotherapy/tamoxifen (520 patients; 11%); (d) surgery scheduling conflict (360 patients; 8%); (e) outside needle biopsy (221 patients; 5%); (f) no residual disease after excisional biopsy (345 patients; 8%); and (g) second opinion only (123 patients; 3%). Other nonparticipation factors included fine needle aspiration only, refusal, tumor size > 2 cm, and estrogen replacement therapy (35 patients each; 2% each). The protocol was amended in midstudy to allow outside needle biopsy, tumor > 2 cm, and estrogen replacement therapy. Accrual to biomarker (nontherapeutic) protocols with delay in definitive cancer surgery is challenging but feasible. Although some accrual problems remain, we have nonetheless succeeded in recruiting 50% of our target sample size in a 3-year period.

Complementation of physiological and behavioral defects by a slowpoke Ca(2+) -activated K(+) channel transgene.

The Drosophila slowpoke gene encodes a large conductance calcium-activated potassium channel used in neurons, muscle, and some epithelial cells. Tissue-specific transcriptional promoters and alternative mRNA splicing generate a large array of transcripts. These distinct transcripts are thought to tailor the properties of the channel to the requirements of the cell. Presumably, a single splice variant cannot satisfy the specific needs of all cell types. To test this, we examined whether a single slowpoke splice variant was capable of complementing all slowpoke behavioral phenotypes. Null mutations in slowpoke cause animals to be semiflightless and to manifest an inducible "sticky-feet" phenotype. The well-characterized slowpoke transcriptional control region was used to direct the expression of a single slowpoke splice variant (cDNA H13) in transgenic flies. The endogenous gene in these flies had been inactivated by the slo(4) mutation. Action-potential recordings and voltage-clamp recordings demonstrated the production of functional channels from the transgene. The transgene completely complemented the flight defect, but not the sticky-feet phenotype. We conclude that distinct slowpoke channel isoforms, produced by alternative splicing, are not interchangeable and are required for proper function of different cell types.

Muscle-specific transcriptional regulation of the slowpoke Ca(2+)-activated K(+) channel gene.

Transcriptional regulation of the Drosophila slowpoke calcium-activated potassium channel gene is complex. To date, five transcriptional promoters have been identified, which are responsible for slowpoke expression in neurons, midgut cells, tracheal cells, and muscle fibers. The slowpoke promoter called Promoter C2 is active in muscles and tracheal cells. To identify sequences that activate Promoter C2 in specific cell types, we introduced small deletions into the slowpoke transcriptional control region. Using transformed flies, we asked how these deletions affected the in situ tissue-specific pattern of expression. Sequence comparisons between evolutionarily divergent species helped guide the placement of these deletions. A section of DNA important for expression in all cell types was subdivided and reintroduced into the mutated control region, a piece at a time, to identify which portion was required for promoter activity. We identified 55-, 214-, and 20-nucleotide sequences that control promoter activity. Different combinations of these elements activate the promoter in adult muscle, larval muscle, and tracheal cells.

Transcriptional control of Ca(2+)-activated K(+) channel expression: identification of a second, evolutionarily conserved, neuronal promoter.

Neuronal signaling properties are largely determined by the quantity and combination of ion channels expressed. The Drosophila slowpoke gene encodes a Ca(2+)-activated K(+) channel used throughout the nervous system. The slowpoke transcriptional control region is large and complex. To simplify the search for sequences responsible for tissue-specific expression, we relied on evolutionary conservation of functionally important sequences. A number of conserved segments were found between two Drosophila species. One led us to a new 5' exon and a new transcriptional promoter: Promoter C0. In larvae and adults, Promoter C0 was demonstrated to be neural-specific using flies transformed with reporter genes that either contain or lack the promoter. The transcription start site of Promoter C0 was mapped, and the exon it appends to the 5' end of the mRNA was sequenced. This is the second neural-specific slowpoke promoter to be identified, the first being Promoter C1. Promoter choice does not alter the encoded polypeptide sequence. RNAase protection assays indicate that Promoter C0 transcripts are approximately 12 times more abundant that Promoter C1 transcripts. Taken together, these facts suggest that promoter choice may be a means for cells to control channel density.