Real-World Toxicity of Conventional Versus Hypofractionated Definitive Prostate Radiotherapy across a Large, Diverse, Academic and Community-Based Enterprise

PURPOSE/OBJECTIVE(S)

Over the past 10-15 years there has been increasing adoption of moderate hypofractionation (HF) for definitive prostate radiotherapy as compared to conventional fractionation (CF). Based on several randomized trials hypofractionation results in equivalent treatment efficacy with similar rates of long-term toxicity. However, some studies suggest higher acute GI toxicity with moderate hypofractionation. We sought to compare the rates of toxicity between these two groups across our enterprise including 16 community-based practices and one academic NCI-designated comprehensive cancer center.

MATERIALS/METHODS

We retrospectively extracted radiation treatment intent from our network-wide clinical pathways for patients diagnosed with prostate cancer between 3/2019 and 10/2022. Patients treated after prostatectomy and those treated with brachytherapy or SBRT were excluded. For the remaining 1529 patients treated with either conventional fractionation or moderate hypofractionation, we identified and merged physician-graded toxicity data using CTCAE version 5.0 recorded in their electronic medical record at each weekly on-treatment visit and follow-up. A total of 1051 patients had toxicity data available. Rates of toxicities were then compared between the cohort of patients who received CF and those who HF using the Chi-square test.

RESULTS

Of the 1051 patients, 450 (43%) received CF and 601 (57%) received HF. These patients were treated by 40 different radiation oncologists (median patients per physician = 18, interquartile range = 7-35). Median age in the CF and HF cohorts was 71 (IQR: 66-76) and 71 (IQR: 66-77; p = 0.51), respectively. The CF cohort had more patients with Gleason 8+ disease (39% vs 19%; p<0.01), PSA >20 (26% vs 11%; p<0.01), or T3a+ (18% vs 8%; p<0.01). Rates of any grade 2+ toxicity were significantly higher in patients who received HF at 45.8% vs 39.6% for those treated with CF (p = 0.04). However, the respective rates of any grade 3+ toxicity were no different at 2.0% vs. 1.8% (p = 0.80). The difference in grade 2 toxicities appeared to be primarily driven by the rates of urinary frequency at 27.1% vs. 17.8% (p<0.01) and prostatic obstruction 14.8% vs. 10.2%, p = 0.03). Rates of grade 2 diarrhea were worse with MF at 5.3% vs. 2.8% for CF (p = 0.04). There were no significant differences between HF and CF in the rates of grade 2 dysuria (6% vs 5.2%), urinary urgency (6.5% vs. 4.2%), proctitis (3.0% vs. 3.6%), urinary incontinence (0.5% vs. 1.3%), rectal bleeding (0.3% vs. 0%), hematuria (0% vs. 0.4%), and fatigue (14.1% vs. 15.1%).

CONCLUSION

In this large network-wide analysis, toxicity was slightly increased among patients with prostate cancer treated with HF compared to CF, consistent with published randomized data. However, the increased toxicity appeared to be primarily GU rather than GI. This study demonstrates the feasibility of analyzing impacts of treatment decisions on a large scale using real-world data through an integrated network of practices.

A Thermodynamic Model for Interpreting Tryptophan Excitation-Energy-Dependent Fluorescence Spectra Provides Insight Into Protein Conformational Sampling and Stability

It is now over 30 years since Demchenko and Ladokhin first posited the potential of the tryptophan red edge excitation shift (REES) effect to capture information on protein molecular dynamics. While there have been many key efforts in the intervening years, a biophysical thermodynamic model to quantify the relationship between the REES effect and protein flexibility has been lacking. Without such a model the full potential of the REES effect cannot be realized. Here, we present a thermodynamic model of the tryptophan REES effect that captures information on protein conformational flexibility, even with proteins containing multiple tryptophan residues. Our study incorporates exemplars at every scale, from tryptophan in solution, single tryptophan peptides, to multitryptophan proteins, with examples including a structurally disordered peptide, de novo designed enzyme, human regulatory protein, therapeutic monoclonal antibodies in active commercial development, and a mesophilic and hyperthermophilic enzyme. Combined, our model and data suggest a route forward for the experimental measurement of the protein REES effect and point to the potential for integrating biomolecular simulation with experimental data to yield novel insights.

Doxycycline compared with prednisolone therapy for patients with bullous pemphigoid: cost-effectiveness analysis of the BLISTER trial

BACKGROUND

Bullous pemphigoid (BP) is an autoimmune blistering skin disorder associated with significant morbidity and mortality. Doxycycline and prednisolone to treat bullous pemphigoid were compared within a randomized controlled trial (RCT).

OBJECTIVES

To compare the cost-effectiveness of doxycycline-initiated and prednisolone-initiated treatment for patients with BP.

METHODS

Quality-of-life (EuroQoL-5D-3L) and resource data were collected as part of the BLISTER trial: a multicentre, parallel-group, investigator-blinded RCT. Within-trial analysis was performed using bivariate regression of costs and quality-adjusted life-years (QALYs), with multiple imputation of missing data, informing a probabilistic assessment of incremental treatment cost-effectiveness from a health service perspective.

RESULTS

In the base case, there was no robust difference in costs or QALYs per patient at 1 year comparing doxycycline- with prednisolone-initiated therapy [net cost £959, 95% confidence interval (CI) -£24 to £1941; net QALYs -0·024, 95% CI -0·088 to 0·041]. However, the findings varied by baseline blister severity. For patients with mild or moderate blistering (≤ 30 blisters) net costs and outcomes were similar. For patients with severe blistering (> 30 blisters) net costs were higher (£2558, 95% CI -£82 to £5198) and quality of life poorer (-0·090 QALYs, 95% CI -0·22 to 0·042) for patients starting on doxycycline. The probability that doxycycline would be cost-effective for those with severe pemphigoid was 1·5% at a willingness to pay of £20 000 per QALY.

CONCLUSIONS

Consistently with the clinical findings of the BLISTER trial, patients with mild or moderate blistering should receive treatment guided by the safety and effectiveness of the drugs and patient preference - neither strategy is clearly a preferred use of National Health Service resources. However, prednisolone-initiated treatment may be more cost-effective for patients with severe blistering.

Ciclosporin compared with prednisolone therapy for patients with pyoderma gangrenosum: cost-effectiveness analysis of the STOP GAP trial

Background

Pyoderma gangrenosum (PG) is a painful, ulcerating skin disease with poor evidence for management. Prednisolone and ciclosporin are the most commonly used treatments, although not previously compared within a randomized controlled trial (RCT).

Objectives

To compare the cost‐effectiveness of ciclosporin and prednisolone‐initiated treatment for patients with PG.

Methods

Quality of life (QoL, EuroQoL five dimensions three level questionnaire, EQ‐5D‐3L) and resource data were collected as part of the STOP GAP trial: a multicentre, parallel‐group, observer‐blind RCT. Within‐trial analysis used bivariate regression of costs and quality‐adjusted life years (QALYs), with multiple imputation of missing data, informing a probabilistic assessment of incremental treatment cost‐effectiveness from a health service perspective.

Results

In the base case analysis, when compared with prednisolone, ciclosporin was cost‐effective due to a reduction in costs [net cost: −£1160; 95% confidence interval (CI) −2991 to 672] and improvement in QoL (net QALYs: 0·055; 95% CI 0·018–0·093). However, this finding appears driven by a minority of patients with large lesions (≥ 20 cm²) (net cost: −£5310; 95% CI −9729 to −891; net QALYs: 0·077; 95% CI 0·004–0·151). The incremental cost‐effectiveness of ciclosporin for the majority of patients with smaller lesions was £23 374/QALY, although the estimate is imprecise: the probability of being cost‐effective at a willingness‐to‐pay of £20 000/QALY was 43%.

Conclusions

Consistent with the clinical findings of the STOP GAP trial, patients with small lesions should receive treatment guided by the side‐effect profiles of the drugs and patient preference – neither strategy is clearly a preferred use of National Health Service resources. However, ciclosporin‐initiated treatment may be more cost‐effective for patients with large lesions.

What's already known about this topic?

Pyoderma gangrenosum is characterized by severe, painful skin ulcers.

Although prednisolone has been the main systemic treatment, ciclosporin has been used increasingly because of its perceived greater effectiveness and fewer side‐effects.

STOP GAP was a pragmatic randomized controlled trial comparing ciclosporin and prednisolone: clinical effectiveness was similar, but only 50% of ulcers had healed by 6 months on either drug and adverse events were common with both drugs.

What does this study add?

For patients with small lesions (< 20 cm²), neither treatment is clearly more cost‐effective than the other.

However, ciclosporin‐initiated treatment may be the more cost‐effective option in patients with large (≥ 20 cm²) lesions.

Decisions about treatment will continue to be informed primarily by patient preference, underlying comorbidities, and drug side‐effect profiles (e.g. serious infections with prednisolone, hypertension and renal dysfunction with ciclosporin).

Linked Comment: Bray. Br J Dermatol 2017; 177:1475–1476.

Plain language summary available online

Antibiotic use in acute pancreatitis: An audit of current practice in a tertiary centre

INTRODUCTION

Intravenous antibiotic prophylaxis is not recommended in acute pancreatitis. According to current international guidelines antibiotics together with further intervention should be considered in the setting of infected necrosis. Appropriate antibiotic therapy particularly avoiding over-prescription is important. This study examines antibiotic use in acute pancreatitis in a tertiary centre using the current IAP/APA guidelines for reference.

METHODS

Data were collected on a consecutive series of patients admitted with acute pancreatitis over a 12 month period. Data were dichotomized by patients admitted directly to the centre and tertiary transfers. Information was collected on clinical course with specific reference to antibiotic use, episode severity, intervention and outcome.

RESULTS

111 consecutive episodes of acute pancreatitis constitute the reported population. 31 (28%) were tertiary transfers. Overall 65 (58.5%) patients received antibiotics. Significantly more tertiary transfer patients received antibiotics. Mean person-days of antibiotic use was 23.9 (sd 29.7) days in the overall study group but there was significantly more use in the tertiary transfer group as compared to patients having their index admission to the centre (40.9 sd 37.1 vs 10.2 sd 8.9; P < 0.005). Thirty four (44%) of patients with clinically mild acute pancreatitis received antibiotics.

CONCLUSIONS

There is substantial use of antibiotics in acute pancreatitis, in particular in patients with severe disease. Over-use is seen in mild acute pancreatitis. Better consideration must be given to identification of prophylaxis or therapy as indication. In relation to repeated courses of antibiotics in severe disease there must be clear indications for use.

Methodological difificulties in rehabilitation research

This paper presents an overview of some of the pitfalls and suggests ways of improving the quality of research into rehabilitation after stroke. The aims of rehabilitation are outlined and methodological problems inherent in this area discussed, including spontaneous recovery, multidimensional outcomes, definition of treatment and placebo effects. Major weaknesses found in the rehabilitation literature are identified and recommendations for improvement made, including the need for comparable controls, adequate numbers, appropriate outcome measures, clear definition of therapy, generalizability, and a concern for the cost-effectiveness of stroke rehabilitation packages. The field of rehabilitation is still relatively new and idiosyncratic in form and content. Thus it still provides opportunities for research into its relative effectiveness before current practices in rehabilitation become entrenched in medical practice and folklore. Adequate funding support for improved, multicentre clinical trials in rehabilitation is essential.

Kinome-wide screening of HER2+ breast cancer cells for molecules that mediate cell proliferation or sensitize cells to trastuzumab therapy

Understanding the signaling differences that distinguish human HER2-amplified (HER2-positive (HER2+)) breast cancers from other breast cancer subtypes may help to identify protein drug targets for the specific treatment of HER2+ breast cancers. We performed two kinome-wide small interfering RNA (siRNA) screens on five HER2+ breast cancer cell lines, seven breast cancer cell lines in which HER2 was not amplified and two normal breast cell lines. To pinpoint the main kinases driving HER2 signaling, we performed a comprehensive siRNA screen that identified loss of the HER2/HER3 heterodimer as having the most prominent inhibitory effect on the growth of HER2+ breast cancer cells. In a second siRNA screen focused on identifying genes that could sensitize HER2+ cells to trastuzumab treatment, we found that loss of signaling members downstream of phosphatidylinositol 3 kinase (PI3K) potentiated the growth inhibitory effects of trastuzumab. Loss of HER2 and HER3, as well as proteins involved in mitogenic and environmental stress pathways inhibited the proliferation of HER2+ cells only in the absence of trastuzumab, suggesting that these pathways are inhibited by trastuzumab treatment. Loss of essential G2/M cell cycle mediators or proteins involved in vesicle organization exerted inhibitory effects on HER2+ cell growth that were unaffected by trastuzumab. Furthermore, the use of a sensitization index (SI) identified targeting the PI3K pathway to sensitize to trastuzumab treatment. Antagonism using the SI identified MYO3A, MYO3B and MPZL1 as antagonizers to trastuzumab treatment among HER2+ cell lines. Our results suggest that the dimerization partners of HER2 are important for determining the activation of downstream proliferation pathways. Understanding the complex layers of signaling triggered downstream of HER2 homodimers and heterodimers will facilitate the selection of better targets for combination therapies intended to treat HER2+ breast cancers.

A prospective trial of temporary sacral nerve stimulation for constipation associated with neurological disease

AIM

This study assessed the effectiveness of temporary sacral nerve stimulation (SNS) in patients with constipation associated with neurological disease using an off-on-off design, and evaluated the long-term response in patients undergoing permanent SNS.

METHOD

Patients with chronic constipation associated with neurological disease receiving specialist clinic care at the University Hospital North Durham over a 2-year period were recruited to a trial of SNS. Recordings of bowel function were made for 6 weeks (baseline) and a temporary electrode was then inserted and recordings were made for the next 3 weeks (stimulation). The electrodes were then removed and assessment was continued for a further 3 weeks (posttreatment). Patient-completed questionnaires were used to determine the severity of constipation (Global Assessment of Symptoms, Constipation, GA Constipation), symptoms (Patient Assessment of Constipation Symptoms score, PAC-SYM) and quality-of-life (Patient Assessment of Constipation-Quality Of Life score, PAC-QOL; European Quality of Life-Five-Domain score; European Quality of Life-Visual Analogue Score). Information was obtained on bowel function and medication. Physiological data were also available for transit and laser Doppler flow cytometry to measure mucosal blood flow.

RESULTS

Twenty-two patients were recruited, of whom 18 completed the trial. GA Constipation reduced significantly during temporary SNS: -1.09 (95% CI -1.59 to -0.59; P = 0.0003). PAC-SYM and PAC-QOL scores showed similar improvements. There was also a significant fall in the time spent in the toilet (P = 0.04) and a decrease in laxative use (P = 0.03). Twelve (67%) patients responded to temporary SNS and received a permanent implant with long-term success in 50%.

CONCLUSION

Sacral nerve stimulation can be effective in treating some patients with refractory severe neuroconstipation. A response to temporary SNS may predict long-term benefit in only half the patients undergoing permanent SNS.

A systematic review and meta-analysis of the topical administration of tranexamic acid in total hip and knee replacement

Intravenous tranexamic acid (TXA) has been shown to be effective in reducing blood loss and the need for transfusion after joint replacement. Recently, there has been interest in applying it topically before the closure of surgical wounds. This has the advantages of ease of application, maximum concentration at the site of bleeding, minimising its systemic absorption and, consequently, concerns about possible side-effects. We conducted a systematic review and meta-analysis which included 14 randomised controlled trials (11 in knee replacement, two in hip replacement and one in both) which investigated the effect of topical TXA on blood loss and rates of transfusion. Topical TXA significantly reduced the rate of blood transfusion (total knee replacement: risk ratio (RR) 4.51; 95% confidence interval (CI): 3.02 to 6.72; p < 0.001 (nine trials, I(2) = 0%); total hip replacement: RR 2.56; 95% CI: 1.32 to 4.97, p = 0.004 (one trial)). The rate of thromboembolic events with topical TXA were similar to those found with a placebo. Indirect comparison of placebo-controlled trials of topical and intravenous TXA indicates that topical administration is superior to the intravenous route. In conclusion, topical TXA is an effective and safe method of reducing the need for blood transfusion after total knee and hip replacement. Further research is required to find its optimum dose for topical use.

Cardiopulmonary exercise testing for preoperative risk assessment before pancreaticoduodenectomy for cancer

OBJECTIVE

Pancreaticoduodenectomy is the standard of care for tumors confined to the head of pancreas and can be undertaken with low operative mortality. The procedure has a high morbidity, particularly in older patient populations with preexisting comorbidities. This study evaluated the role of cardiopulmonary exercise testing to predict postoperative morbidity and outcome in high-risk patients undergoing pancreaticoduodenectomy.

METHODS

In a prospective cohort of consecutive patients undergoing pancreaticoduodenectomy, those aged over 65 years (or younger with comorbidity) were categorized as high risk and underwent preoperative assessment by cardiopulmonary exercise testing (CPET) according to a predefined protocol. Data were collected on functional status, postoperative complications, and survival.

RESULTS

A total of 143 patients underwent preoperative assessment, 50 of whom were deemed to be at low risk for surgery per study protocol. Of 93 high-risk patients, 64 proceeded to surgery after preoperative CPET. Neither anaerobic threshold (AT) nor maximal oxygen consumption ([Formula: see text] O 2 MAX) predicted patient mortality or morbidity. However, ventilatory equivalent of carbon dioxide ([Formula: see text] E/[Formula: see text] CO 2) at AT was a predictive marker of postoperative mortality, with an area under the curve (AUC) of 0.84 (95 % confidence interval [CI] 0.63-1.00, p = 0.020); a threshold of 41 was 75 % sensitive and 95 % specific (positive predictive value 50 %, negative predictive value 98 %). Above this threshold, raised [Formula: see text] E/[Formula: see text] CO 2 predicted poor long-term survival (hazard ratio 2.05, 95 % CI 1.09-3.86, p = 0.026).

CONCLUSIONS

CPET is a useful adjunctive test for predicting postoperative outcome in patients being assessed for pancreaticoduodenectomy. Raised CPET-derived [Formula: see text] E/[Formula: see text] CO 2 predicts early postoperative death and poor long-term survival.

Topical treatments for chronic plaque psoriasis of the scalp: a systematic review

BACKGROUND

Chronic plaque psoriasis is the most common type of psoriasis and is characterized by redness, thickness and scaling. First-line management is with topical treatments.

OBJECTIVES

Our objective was to establish the effectiveness, tolerability and safety of topical treatments for people with chronic plaque psoriasis of the scalp, assessing placebo-controlled trials of all treatments and head-to-head trials that assessed vitamin D analogues.

METHODS

As part of a Cochrane review of topical treatments for psoriasis, we systematically searched electronic databases for randomized controlled trials. The review included 26 randomized controlled trials of treatments for psoriasis of the scalp with 8020 participants. Trials used several measures to assess changes in psoriasis severity: these were combined using the standardized mean difference metric and interpreted by reporting as a six-point global improvement score.

RESULTS

On effectiveness grounds, very potent or potent steroid treatments should be preferred to vitamin D3 analogue with approximately an average 10% additional improvement on a six-point scale. Vitamin D3 analogue combined with potent steroid appears slightly more effective than potent steroid monotherapy (3% additional improvement on a six-point scale). Rates of withdrawal from treatment and adverse events in trials were generally low and similar to those for placebo. There remains uncertainty about the atrophic potential of corticosteroid treatments for scalp psoriasis.

CONCLUSIONS

Corticosteroids are more effective than vitamin D analogues and similarly tolerated. However, further research is needed to inform long-term maintenance treatment and provide appropriate safety data.

Role of Nek2 on centrosome duplication and aneuploidy in breast cancer cells

Breast cancer is the most common solid tumor and the second most common cause of death in women. Despite a large body of literature and progress in breast cancer research, many molecular aspects of this complex disease are still poorly understood, hindering the design of specific and effective therapeutic strategies. To identify the molecules important in breast cancer progression and metastasis, we tested the in vivo effects of inhibiting the functions of various kinases and genes involved in the regulation/modulation of the cytoskeleton by downregulating them in mouse PyMT mammary tumor cells and human breast cancer cell lines. These kinases and cytoskeletal regulators were selected based on their prognostic values for breast cancer patient survival. PyMT tumor cells, in which a selected gene was stably knocked down were injected into the tail veins of mice, and the formation of tumors in the lungs was monitored. One of the several genes found to be important for tumor growth in the lungs was NIMA-related kinases 2 (Nek2), a cell cycle-related protein kinase. Furthermore, Nek2 was also important for tumor growth in the mammary fat pad. In various human breast cancer cell lines, Nek2 knockdown induced aneuploidy and cell cycle arrest that led to cell death. Significantly, the breast cancer cell line most sensitive to Nek2 depletion was of the triple negative breast cancer subtype. Our data indicate that Nek2 has a pivotal role in breast cancer growth at primary and secondary sites, and thus may be an attractive and novel therapeutic target for this disease.

Cardiopulmonary exercise testing for preoperative risk assessment before hepatic resection

BACKGROUND

Contemporary liver surgery practice must accurately assess operative risk in increasingly elderly populations with greater co-morbidity. This study evaluated preoperative cardiopulmonary exercise testing (CPET) in high-risk patients undergoing hepatic resection.

METHODS

In a prospective cohort referred for liver resection, patients aged over 65 years (or younger with co-morbidity) were evaluated by preoperative CPET. Data were collected prospectively on functional status, postoperative complications and survival.

RESULTS

Two hundred and four patients were assessed for hepatic resection, of whom 108 had preoperative CPET. An anaerobic threshold (AT) of 9·9 ml O(2) per kg per min predicted in-hospital death and subsequent survival. Below this value, AT was 100 per cent sensitive and 76 per cent specific for in-hospital mortality, with a positive predictive value (PPV) of 19 per cent and a negative predictive value (NPV) of 100 per cent: no deaths occurred above the threshold. Age and respiratory efficiency in the elimination of carbon dioxide (VE/VCO(2)) at AT were statistically significant predictors of postoperative complications. Receiver operating characteristic (ROC) curve analysis showed that a threshold of 34·5 for VE/VCO(2) at AT provided a specificity of 84 per cent and a sensitivity of 47 per cent, with a PPV of 76 (95 per cent confidence interval (c.i.) 58 to 88) per cent and a NPV of 60 (48 to 72) per cent for postoperative complications. Long-term survival of those with an AT of less than 9·9 ml O(2) per kg per min was significantly worse than that of patients with a higher AT (hazard ratio for mortality 1·81, 95 per cent c.i. 1·04 to 3·17; P = 0·036).

CONCLUSION

CPET provides a useful prognostic adjunct in the preoperative assessment of patients undergoing hepatic resection.

Tranexamic acid in total knee replacement: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis of randomised controlled trials evaluating the effect of tranexamic acid (TXA) upon blood loss and transfusion in primary total knee replacement. The review used the generic evaluation tool designed by the Cochrane Bone, Joint and Muscle Trauma Group. A total of 19 trials were eligible: 18 used intravenous administration, one also evaluated oral dosing and one trial evaluated topical use. TXA led to a significant reduction in the proportion of patients requiring blood transfusion (risk ratio (RR) 2.56, 95% confidence interval (CI) 2.1 to 3.1, p < 0.001; heterogeneity I(2) = 75%; 14 trials, 824 patients). Using TXA also reduced total blood loss by a mean of 591 ml (95% CI 536 to 647, p < 0.001; I(2) = 78%; nine trials, 763 patients). The clinical interpretation of these findings is limited by substantial heterogeneity. However, subgroup analysis of high-dose (> 4 g) TXA showed a plausible consistent reduction in blood transfusion requirements (RR 5.33; 95% CI 2.44 to 11.65, p < 0.001; I(2) = 0%), a finding that should be confirmed by a further well-designed trial. The current evidence from trials does not support an increased risk of deep-vein thrombosis (13 trials, 801 patients) or pulmonary embolism (18 trials, 971 patients) due to TXA administration.

Systematic review and meta-analysis of the use of tranexamic acid in total hip replacement

We report a systematic review and meta-analysis of published randomised controlled trials evaluating the efficacy of tranexamic acid (TXA) in reducing blood loss and transfusion in total hip replacement (THR). The data were evaluated using the generic evaluation tool designed by the Cochrane Bone, Joint and Muscle Trauma Group. We identified 11 clinical trials which were suitable for detailed extraction of data. There were no trials that used TXA in revision THR. A total of seven studies (comprising 350 patients) were eligible for the blood loss outcome data. The use of TXA reduced intra-operative blood loss by a mean of 104 ml (95% confidence interval (CI) -164 to -44, p = 0.0006, heterogeneity I(2) 0%), postoperative blood loss by a mean of 172 ml (95% CI -263 to -81, p = 0.0002, heterogeneity I(2) 63%) and total blood loss by a mean of 289 ml (95% CI -440 to -138, p < 0.0002, heterogeneity I(2) 54%). TXA led to a significant reduction in the proportion of patients requiring allogeneic blood transfusion (risk difference -0.20, 95% CI -0.29 to -0.11, p < 0.00001, I(2) 15%). There were no significant differences in deep-vein thrombosis, pulmonary embolism, infection rates or other complications among the study groups.

Regulation of telomere length in Drosophila

Telomeres in all organisms must perform the same vital functions to ensure cell viability: to act as a protective chromosome cap that distinguishes natural chromosome ends from DNA double strand breaks, and to balance the loss of DNA from the chromosome end due to incomplete DNA replication. Most eukaryotes rely on a specialized reverse transcriptase, telomerase, to generate short repeats at the chromosome end to maintain chromosome length. Drosophila, however, uses retrotransposons that target telomeres. Transposition of these elements may be controlled by small RNAs and spreading of silent chromatin from the telomere associated sequence, both of which limit the retrotransposon expression level. Proteins binding to the retrotransposon array, such as HP1 and PROD, may also modulate transcription. It is not clear however, that simply increasing transcript levels of the telomeric retrotransposons is sufficient to increase transposition. The chromosome cap may control the ability of the telomere-specific elements to attach to chromosome ends. As in other organisms, chromosomes can be elongated by gene conversion. Although the mechanism is not known, HP1, a component of the cap, and the Ku proteins are key components in this pathway.

Helicobacter pylori eradication in long-term proton pump inhibitor users is highly cost-effective: economic analysis of the HELPUP trial

BACKGROUND

Proton pump inhibitor (PPI) use is costly and about two-thirds of prescribing is long-term. Although 20-50% of patients may be infected with Helicobacter pylori, eradication is not normal clinical practice.

AIM

To establish if H. pylori eradication in long-term PPI users is cost-effective.

METHODS

Long-term PPI-using patients (n = 183) testing positive for H. pylori were randomly assigned to true or placebo eradication therapy. Patients provided 2-year resource data, and 1-year symptom severity scores. A within-trial cost effectiveness analysis was conducted from a British health service perspective.

RESULTS

Significant reductions in resource use occurred comparing eradication with placebo. After 2 years, PPI prescriptions (full-dose equivalents) fell by 3.9 (P < 0.0001); clinician (GP) consultations by 2.4 (P = 0.0001); upper gastrointestinal (GI) endoscopies by 14.8% (P = 0.008); clinician GI-related home visits by 19.9% (P = 0.005) and abdominal ultrasound scans fell by 20.3% (P = 0.005). Average net savings/patient were pound93 (95% CI: 33-153) after costs of detection and eradication had been deducted. At 1 year, Leeds Dyspepsia Questionnaire symptoms fell by 3.1 (P = 0.005) and quality-of-life measures improved (EuroQol-5D: 0.089, P = 0.08; visual analogue scale: 5.6, P = 0.002) favouring eradication.

CONCLUSION

Helicobacter pylori eradication in infected, long-term PPI users is an economically dominant strategy, significantly reducing overall healthcare costs and symptom severity.

WITHDRAWN: Treatment discontinuation with selective serotonin reuptake inhibitors (SSRIs) versus tricyclic antidepressants (TCAs)

BACKGROUND

Selective serotonin reuptake inhibitors are thought to have better discontinuation rates (i.e. less people dropping out) than tricyclic and heterocyclic antidepressant drugs. It is important to quantify the drop-out rates of different antidepressant drugs in order to have a better understanding of the relative tolerability of these drugs.

OBJECTIVES

To assess the comparative tolerability of selective serotonin reuptake inhibitors and tricyclic/heterocyclic antidepressant drugs.

SEARCH STRATEGY

We searched the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Registers (1997 to 1999), MEDLINE (1966 to 1999), EMBASE (1974 to 1999) We also searched specialist journals, the reference lists of relevant papers and previous systematic reviews, conference abstracts and government documents. Representatives of the pharmaceutical industry were contacted.

SELECTION CRITERIA

Parallel group randomised controlled trials comparing selective serotonin reuptake inhibitors with tricyclic or heterocyclic antidepressants in people with depression.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and a third reviewer checked any cases of disagreement.

MAIN RESULTS

We included 136 trials. The selective serotonin reuptake inhibitors showed less participants dropping out compared to the tricyclic/heterocyclic group (odds ratio 1.21, 95% confidence interval 1.12 to 1.30). A statistically significant difference was found in total drop-outs between the selective serotonin reuptake inhibitors and the old tricyclics as well as the newer tricyclics. When the selective serotonin reuptake inhibitors were compared to the heterocyclic antidepressants, there was a non significant difference favouring the selective serotonin reuptake inhibitors. The poor tolerability profile of the old tricyclics was explained by differences in drop-outs for side-effects, but not for inefficacy.

AUTHORS' CONCLUSIONS

Whilst selective serotonin reuptake inhibitors do appear to show an advantage over tricyclic drugs in terms of total drop-outs, this advantage is relatively modest. This has implications for pharmaco-economic models, some of which may have overestimated the difference of drop-out rates between selective serotonin reuptake inhibitors and tricyclic antidepressants. These results are based on short-term randomised controlled trials, and may not generalise into clinical practice.

Managing dyspepsia without alarm signs in primary care: new national guidance for England and Wales

AIM

To report new recommendations for the primary care management of dyspepsia without alarm signs in England and Wales.

METHOD

An independent, representative group of health care professionals, patient representatives and researchers developed the guideline using evidence-based and small group-working principles, and incorporated extensive peer-reviewing and feedback from stakeholder organizations.

RESULTS

Referral to investigate dyspepsia should be made for alarm signs and not on the basis of age alone, reflecting the balance of benefit and harm from endoscopy. Empirical management without formal diagnosis is appropriate for most patients: reviewing patient history, lifestyle, over-the-counter medicines, and providing a course of proton-pump inhibitors and/or Helicobacter pylori test and treatment. Patients with ongoing symptoms require at least annual review to discuss symptoms and lifestyle, and as appropriate, encourage stepping down prescribed medication and returning to self-care. A new strategy included in the step down process is the use of therapies 'on-demand'.

CONCLUSION

The guideline provides structured and supported recommendations for both undiagnosed and endoscopically investigated dyspepsia. Some favour increased investigation to detect Barrett's oesophagus and carcinoma. However, there is inconclusive evidence that patients without alarm signs will benefit subsequently from endoscopy, while investigation involves a small but real risk of harm.

Sonic hedgehog gene-enhanced tissue engineering for bone regeneration

Improved methods of bone regeneration are needed in the craniofacial rehabilitation of patients with significant bone deficits secondary to tumor resection, congenital deformities, and prior to prosthetic dental reconstruction. In this study, a gene-enhanced tissue-engineering approach was used to assess bone regenerative capacity of Sonic hedgehog (Shh)-transduced gingival fibroblasts, mesenchymal stem cells, and fat-derived cells delivered to rabbit cranial bone defects in an alginate/collagen matrix. Human Shh cDNA isolated from fetal lung tissue was cloned into the replication-incompetent retroviral expression vector LNCX, in which the murine leukemia virus retroviral LTR drives expression of the neomycin-resistance gene. The rat beta-actin enhancer/promoter complex was engineered to drive expression of Shh. Reverse transcriptase-polymerase chain reaction analysis demonstrated that the transduced primary rabbit cell populations expressed Shh RNA. Shh protein secretion was confirmed by enzyme-linked immunosorbent assay (ELISA). Alginate/ type I collagen constructs containing 2 x 10(6) Shh-transduced cells were introduced into male New Zealand White rabbit calvarial defects (8 mm). A total of eight groups (N=6) were examined: unrestored empty defects, matrix alone, matrix plus the three cell populations transduced with both control and Shh expression vectors. The bone regenerative capacity of Shh gene enhanced cells was assessed grossly, radiographically and histologically at 6 and 12 weeks postimplantation. After 6 weeks, new full thickness bone was seen emanating directly from the alginate/collagen matrix in the Shh-transduced groups. Quantitative two-dimensional digital analysis of histological sections confirmed statistically significant (P<0.05) amounts of bone regeneration in all three Shh-enhanced groups compared to controls. Necropsy failed to demonstrate any evidence of treatment-related side effects. This is the first study to demonstrate that Shh delivery to bone defects, in this case through a novel gene-enhanced tissue-engineering approach, results in significant bone regeneration. This encourages further development of the Shh gene-enhanced tissue-engineering approach for bone regeneration.

Educational outreach in diabetes to encourage practice nurses to use primary care hypertension and hyperlipidaemia guidelines (EDEN): a randomized controlled trial

OBJECTIVE

To determine the effectiveness of specialist nurse delivered education in primary care to improve control of hypertension and hyperlipidaemia in patients with diabetes.

DESIGN AND SETTING

Practice-level randomized controlled trial, Salford, England.

SUBJECTS

From 44 practices, 10 303 subjects presenting in general practice with raised blood pressure (= 140/80 mmHg), raised total cholesterol (= 5.0 mmol/l) or both.

INTERVENTIONS

Practices were randomized to receive either the intervention for hyperlipidaemia or for hypertension; practices acted as control for the intervention not received. Specialist nurses arranged a schedule of visits with general practitioners and general practice nurses, reminding them of diabetes protocols and clinical targets. They provided educational materials and protocols used in secondary care for nurse and doctor interventions including stepping up pharmacotherapy when necessary. Practices received a list of patients in their practice who were poorly controlled at their last annual review; new and recalled patients were targeted.

OUTCOME MEASURES

At subsequent annual review, blood pressure and total cholesterol values were obtained from the Salford electronic diabetes register for patients from participating practices.

RESULTS

Overall, specialist nurse-led educational outreach to primary care was associated with no improvement in patients achieving target after 1 year-odds ratio (OR): 1.03 (95% CI 0.95-1.11; P = 0.52). Similar results were achieved with hyperlipidaemia OR: 1.04 (95% CI 0.88-1.23; P = 0.62) and hypertension OR: 1.01 (95% CI 0.80-1.27; P = 0.93).

CONCLUSION

This study provides evidence that the use of specialist nurses to perform educational outreach to improve target adherence to patients with diabetes in primary care is not effective.

Telomerase-independent mechanisms of telomere elongation

The ends of linear chromosomes must be elongated in a DNA-replication-independent fashion. For chromosome end elongation the majority of eukaryotes use a specialized reverse transcriptase, telomerase, which adds a short, tandemly repeated DNA sequence motif to chromosome ends. Chromosome elongation can also be achieved, however, by mechanisms other than telomerase. Such elongation events have been detected under conditions where telomerase has been inactivated experimentally and in the few organisms that naturally lack telomerase. We will summarize current knowledge on these telomerase-independent elongation mechanisms in yeast and mammalian cells and will discuss in more detail the telomere elongation mechanism by retrotransposons in Drosophila melanogaster.

Gene expression patterns of paired bronchioloalveolar carcinoma and benign lung tissue

A variant of adenocarcinoma, bronchioloalveolar carcinoma (BAC), has increased in incidence since 1950 and now represents 2-14% of all lung cancers. There has been concomitant diminution in the proportion of squamous cell carcinoma, the most common form of primary lung cancer. The BAC form of adenocarcinoma occurs disproportionately in women, has an earlier age of onset than conventional pulmonary carcinoma, and is not linked to smoking. The increased incidence of BAC in both smokers and non-smokers suggests that BAC may have an environmental etiology other than smoking. To explore this possibility, we compared the patterns of gene expression in paired samples of tumor and normal lung tissue from 3 patients with a pathologic diagnosis of BAC. Characterization of the gene expression patterns of the paired tissue samples was performed by oligonucleotide microarray analysis of 12,000 known genes and expressed sequence tags (ESTs). We identified 12 genes that were up-regulated > or = 2-fold in all 3 tumors and 6 genes that were down-regulated in all 3 tumors to < or = 0.20 times the baseline. These findings suggest that large scale transcriptional profiling of BAC tumors may disclose a pattern of altered cellular expression in response to genetic changes, diseases, and environmental insult; such transcriptional profiling may aid in diagnosis and therapy.

Control of telomere elongation and telomeric silencing in Drosophila melanogaster

Chromosome length in Drosophila is maintained by the targeted transposition of two families of non-LTR retrotransposons, HeT-A and TART. Although the rate of transposition to telomeres is sufficient to counterbalance loss from the chromosome ends due to incomplete DNA replication, transposition as a mechanism for elongating chromosome ends raises the possibility of damaged or deleted telomeres, because of its stochastic nature. Recent evidence suggests that HeT-A transposition is controlled at the levels of transcription and reverse transcription. HeT-A transcription is found primarily in mitotically active cells, and transcription of a w+ reporter gene inserted into the 2L telomere increases when the homologous telomere is partially or completely deleted. The terminal HeT-A array may be important as a positive regulator of this activity in cis, and the subterminal satellite appears to be an important negative regulator in cis. A third chromosome modifier has been identified that increases the level of reverse transcriptase activity on a HeT-A RNA template and greatly increases the transposition of HeT-A. Thus, the host appears to play a role in transposition of these elements. Taken together, these results suggest that control of HeT-A transposition is more complex than previously thought.

Terminal retrotransposons activate a subtelomeric white transgene at the 2L telomere in Drosophila

Genetically marked P elements inserted into the subtelomeric satellites of Drosophila show repression and variegation of the reporter gene. One such white+ reporter, inserted between the subtelomeric satellite and the terminal HeT-A array in the left arm of chromosome 2 (2L), is sensitive to its context; changes in the structure of the telomere region can be identified by changes in eye color. Addition of HeT-A or TART elements to the 2L terminus increases w+ expression, and loss of sequence from the end decreases expression. This indicates that the telomeric retrotransposons in Drosophila have an activating influence on the repressed subterminal reporter gene. Changes in eye color due to altered expression of the transgene also allow the detection of interactions between homologous telomeres. The 2L arms that terminate in long HeT-A/TART arrays showed increased expression of the subterminal w+ transgene when the terminal repeats on the homologue are absent or markedly shorter. We propose that the chromatin structure of the terminal HeT-A/TART array and the activity of a putative promoter/enhancer element on HeT-A are affected by telomeric interactions. Such trans-activation may reflect control over HeT-A transcription and, thus, transposition activity.

Treatment of Ischemic Wounds Using Cultured Dermal Fibroblasts Transduced Retrovirally With PDGF-B and VEGF121 Genes

The healing of ischemic wounds is a particularly difficult clinical challenge. In this study, rabbit dermal fibroblasts transduced retrovirally with human platelet-derived growth factor B (PDGF-B) and human vascular endothelial growth factor 121 (VEGF121) genes were used to treat wounds in a rabbit ischemic ear model. The PDGF-B and VEGF121 genes were obtained from human umbilical vein endothelial cells (HUVECs) by reverse transcription-polymerase chain reaction, cloned into retroviral vectors under control of the beta-actin promoter, and introduced into primary rabbit dermal fibroblast cells. In vitro results demonstrated that rabbit dermal fibroblasts are transduced and selected readily using retroviral vectors, and are engineered to secrete PDGF-B and VEGF121 at steady-state levels of 150 ng per 10(6) cells per 24 hours and 230 ng per 10(6) cells per 24 hours respectively. These cells were then seeded onto polyglycolic acid (PGA) scaffold matrices and used to treat ischemic rabbit ear wounds. Immunohistochemistry showed intense staining for PDGF-B and VEGF121 in the wounds treated with these transduced cells compared with the control treatment groups. For the relatively more ischemic distal ear wounds, granulation tissue deposition was increased significantly in the wounds treated with PDGF-B- and VEGF121-transduced cells compared with wounds treated with PGA alone. These results demonstrate that gene augmentation of rabbit dermal fibroblasts with the PDGF-B and VEGF121 genes introduced into this ischemic wound model via PGA matrices modulates wound healing, and may have clinical potential in the treatment of ischemic wounds.

A common epitope is shared by activated signal transducer and activator of transcription-5 (STAT5) and the phosphorylated erythropoietin receptor: implications for the docking model of STAT activation

Erythropoietin (EPO) specifically activates the Janus kinase JAK2 and the transcription factor signal transducer and activator of transcription-5 (STAT5). All members of the STAT family are tyrosine phosphorylated in response to cytokine stimulation at a conserved carboxy-terminal tyrosine, Y694, in the case of STAT5. To determine structural features important for STAT signaling, we generated an activation-specific STAT5 antibody using a phosphopeptide containing amino acids 687 to 698 of STAT5 as antigen. This antibody specifically recognizes tyrosine- phosphorylated STAT5 but not nonphosphorylated STAT5. In immunoprecipitation reactions from cell lines and primary erythroblasts, 2 distinct polyclonal activation-specific STAT5 antibodies selectively immunoprecipitate the tyrosine phosphorylated EPO receptor (EPO-R) in addition to STAT5 under native and denaturing conditions. We propose that the activation-specific STAT5 antibody recognizes the 2 substrates to which the STAT5 SH2 domain interacts, namely, the tyrosine- phosphorylated EPO-R and STAT5 itself. Several studies have implicated EPO-R Y343, Y401, Y431, and Y479 in the recruitment of STAT5. Using a series of EPO-R tyrosine mutants expressed in Ba/F3 cells, we have shown that the activation-specific STAT5 antibody immunoprecipitates an EPO-R containing only 2 tyrosines at positions 343 and 401, confirming the importance of these tyrosines in STAT5 recruitment. These data uncover a novel aspect of STAT SH2 domain recognition and demonstrate the utility of activation-specific antibodies for examining the specificity of STAT-cytokine receptor interactions.

Reverse transcriptase can stabilize or destabilize the genome

Telomeres, the eukaryotic chromosome termini, are deoxyribonucleoprotein structures that distinguish natural chromosome ends from broken DNA. In most organisms, telomeres are extended by a reverse transcriptase (RT) with an integrated RNA template, telomerase; in Drosophila melanogaster, however, telomere-specific retrotransposons, HeT-A and TART transpose specifically to chromosome ends. Whether telomeres are extended by a telomerase or by retrotransposons, an RT is a key component. RT has been studied extensively, both for its important role in converting RNA genomes to DNA, which has great evolutionary impact, and as a therapeutic target in human retroviral diseases. Here we discuss a few important aspects of RT usage during retrotransposition and telomere elongation.

Rab6c, a new member of the rab gene family, is involved in drug resistance in MCF7/AdrR cells

A new Rab6 homolog cDNA, Rab6c, was discovered by a hypermethylated DNA fragment probe that was isolated from a human multidrug resistant (MDR) breast cancer cell line, MCF7/AdrR, by the methylation sensitive-representational difference analysis (MS-RDA) technique. Rab6c was found to be under-expressed in MCF7/AdrR and MES-SA/Dx5 (a human MDR uterine sarcoma cell line) compared with their non-MDR parental cell lines. MCF7/AdrR cells expressing the exogenous Rab6c exhibited less resistance to several anti-cancer drugs, such as doxorubicin (DOX), taxol, vinblastine, and vincristine, than the control cells containing the empty vector. Flow cytometry experiments confirmed that the transfectants' diminished resistance to DOX was caused by increased drug accumulation induced by the exogenous Rab6c. These results indicate that Rab6c is involved in drug resistance in MCF7/AdrR cells.

Cartilage and bone regeneration using gene-enhanced tissue engineering

Joint cartilage injury remains a major problem in orthopaedics with more than 500,000 cartilage repair procedures performed yearly in the United States at a cost of hundreds of millions of dollars. No consistently reliable means to regenerate joint cartilage currently exists. The technologies of gene therapy and tissue engineering were combined using a retroviral vector to stably introduce the human bone morphogenic protein-7 complementary deoxyribonucleic acid into periosteal-derived rabbit mesenchymal stem cells. Bone morphogenic protein-7 secreting gene modified cells subsequently were expanded in monolayer culture, seeded onto polyglycolic acid grafts, implanted into a rabbit knee osteochondral defect model, and evaluated for bone and cartilage repair after 4, 8, and 12 weeks. The grafts containing bone morphogenic protein-7 gene modified cells consistently showed complete or near complete bone and articular cartilage regeneration at 8 and 12 weeks whereas the grafts from the control groups had poor repair as judged by macroscopic, histologic, and immunohistologic criteria. This is the first report of articular cartilage regeneration using a combined gene therapy and tissue engineering approach.

Hepatocyte growth factor decreases sensitivity to chemotherapeutic agents and stimulates cell adhesion, invasion, and migration

Hepatocyte growth factor (HGF), also known as scatter factor (SF), plays an important role in cell:cell adhesion, cell proliferation, motility, and invasiveness of epithelial cells and tumor cells. In this study, we examined the effects of HGF on these types of biological activities and chemosensitivity in Chinese hamster ovary (CHO) cells by stable transfection of the HGF gene. HGF-transfected clones produced very high titers of HGF protein, whereas control vector-transfected clones did not produce detectable HGF protein. HGF-transfected clones showed modestly increased proliferation rates and became more resistant to cell death and apoptosis caused by two anticancer drugs, adriamycin (ADR) and camptothecin (CPT), compared to controlvector-transfected clones. Furthermore, HGF-transfected clones also exhibited increased activities of cell adhesion, migration, and invasion. The current study is the first demonstration that overexpression of the HGF gene affects chemosensitivity and cell metastasis behaviors, suggesting that HGF signaling pathway is a promising new target of therapeutic intervention of tumors.

Dysregulated expression of ebaf, a novel molecular defect in the endometria of patients with infertility

We recently described the expression of ebaf, a novel member of the transforming growth factor-beta superfamily in human endometrium. ebaf messenger ribonucleic acid was expressed in late secretory and menstrual endometria. Here, we show that ebaf is secreted as 42-, 34-, 28-, and 14-kDa proteins into the conditioned medium of transfected cells, endometrial fluid, and serum. The amount of secreted proteins was markedly reduced during the implantation window in the endometria and sera of normal fertile subjects. The expression of ebaf was dysregulated in the endometria of a subset of women with infertility during the receptive phase of the menstrual cycle. Abundant secreted protein was present in the endometria of these women during the implantation window. During the critical period of endometrial receptivity, ebaf protein was more abundant in patients with endometriosis who did not conceive than in patients who became pregnant. These findings show that ebaf is a secreted product and is released into body fluids. Some types of infertility are associated with dysregulated expression of ebaf in human endometrium, suggesting that a molecular defect in uterine receptivity may be identified using such a marker protein.

Effects of mutations on the thermodynamics of a protein folding reaction: implications for the mechanism of formation of the intermediate and transition states

We have measured changes in heat capacity, entropy, and enthalpy for each step in the folding reaction of CD2.d1 and evaluated the effects of core mutations on these properties. All wild-type and mutant forms fold through a rapidly formed intermediate state that precedes the rate-limiting transition state. Mutations have a pronounced effect on the enthalpy of both the intermediate and folded states, but in all cases a compensatory change in entropy results in a small net free-energy change. While the enthalpy change in the folded state can be attributed to a loss of van der Waals interactions, it has already been shown that changes in the stability of the intermediate are dominated by changes in secondary structure propensity [Lorch et al. (1999) Biochemistry 38, 1377-1385]. It follows that the thermodynamic basis of beta-propensity is enthalpic in origin. The effects of mutations on the enthalpy and entropy of the transition state are smaller than on the ground states. This relative insensitivity to mutation is discussed in the light of theories concerning the nature of the rate-limiting barrier in folding reactions.

The SH2 inositol 5-phosphatase Ship1 is recruited in an SH2-dependent manner to the erythropoietin receptor

Ship1 (SH2 inositol 5-phosphatase 1) has been shown to be a target of tyrosine phosphorylation downstream of cytokine and immunoregulatory receptors. In addition to its catalytic activity on phosphatidylinositol substrates, it can serve as an adaptor protein in binding Shc and Grb2. Erythropoietin (EPO), the primary regulator of erythropoiesis, has been shown to activate the tyrosine phosphorylation of Shc, resulting in recruitment of Grb2. However, the mechanism by which the erythropoietin receptor (EPO-R) recruits Shc remains unknown. EPO activates the tyrosine phosphorylation of Ship1, resulting in the interdependent recruitment of Shc and Grb2. Ship1 is recruited to the EPO-R in an SH2-dependent manner. Utilizing a panel of EPO-R deletion and tyrosine mutants, we have discovered remarkable redundancy in Ship1 recruitment. EPO-R Tyr(401) appears to be a major site of Ship1 binding; however, Tyr(429) and Tyr(431) can also serve to recruit Ship1. In addition, we have shown that EPO stimulates the formation of a ternary complex consisting of Ship1, Shc, and Grb2. Ship1 may modulate several discrete signal transduction pathways. EPO-dependent activation of ERK1/2 and protein kinase B (PKB)/Akt was examined utilizing a panel of EPO-R deletion mutants. Activation of ERK1/2 was observed in EPO-RDelta99, which retains only the most proximal tyrosine, Tyr(343). In contrast, EPO-dependent PKB activation was observed in EPO-RDelta43, but not in EPO-RDelta99. It appears that EPO-dependent PKB activation is downstream of a region that indirectly couples to phosphatidylinositol 3-kinase.

Population-based and opportunistic screening and eradication of Helicobacter pylori. An analysis using trial baseline data. Leeds H. pylori Study Group

OBJECTIVES

To examine whether screening and eradication of Helicobacter pylori by population-based invitation or opportunistic screening by general practitioners reduces costs to the National Health Service (NHS) of treating dyspepsia.

METHODS

A limited dependent, variable, two-step regression analysis was used to explore the baseline annual health care costs of dyspepsia for men and women aged 40-49 enrolled in the Leeds H. pylori screening and eradication trial.

RESULTS

Epidemiological and clinical questionnaires, general practitioner notes, and 13C urea breath test results were available for 4,754 individuals. After adjusting for covariates H. pylori was associated with a 6.7% increased probability of incurring gastrointestinal-related NHS costs (p < .0001) in the population aged 40-49. Additionally, H pylori increased average costs in those who seek medical care (p = .001). In consequence, H. pylori is associated with an average increased cost to the NHS of 0.30 Pound per year (95% CI: 0.17 Pound to 0.45 Pound) per adult aged 40-49. In those consulting for dyspepsia, the increased cost to the NHS was 1.04 Pounds per year (95% CI: 0.42 Pound to 1.75 Pounds) per patient. The cost of population screening and treatment would not be recovered in reduced dyspepsia costs in the lifetime of those screened. Assuming laboratory-based serology screening is used opportunistically in patients presenting with dyspepsia, it is estimated that costs would be recouped in 18 years.

CONCLUSIONS

This observational data set suggests that the costs of screening and treatment in all individuals aged 40-49 or in those presenting in primary care with dyspeptic symptoms are unlikely to be attractive on the basis of cost savings alone.

Selective serotonin reuptake inhibitors versus tricyclic and heterocyclic antidepressants: comparison of drug adherence

BACKGROUND

Selective serotonin reuptake inhibitors are thought to have better discontinuation rates (i.e. less people dropping out) than tricyclic and heterocyclic antidepressant drugs. It is important to quantify the drop-out rates of different antidepressant drugs in order to have a better understanding of the relative tolerability of these drugs.

OBJECTIVES

To assess the comparative tolerability of selective serotonin reuptake inhibitors and tricyclic/heterocyclic antidepressant drugs.

SEARCH STRATEGY

We searched the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Registers (1997 to 1999), MEDLINE (1966 to 1999), EMBASE (1974 to 1999) We also searched specialist journals, the reference lists of relevant papers and previous systematic reviews, conference abstracts and government documents. Representatives of the pharmaceutical industry were contacted.

SELECTION CRITERIA

Parallel group randomised controlled trials comparing selective serotonin reuptake inhibitors with tricyclic or heterocyclic antidepressants in people with depression.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and a third reviewer checked any cases of disagreement.

MAIN RESULTS

We included 136 trials. The selective serotonin reuptake inhibitors showed less participants dropping out compared to the tricyclic/heterocyclic group (odds ratio 1.21, 95% confidence interval 1.12 to 1.30). A statistically significant difference was found in total drop-outs between the selective serotonin reuptake inhibitors and the old tricyclics as well as the newer tricyclics. When the selective serotonin reuptake inhibitors were compared to the heterocyclic antidepressants, there was a non significant difference favouring the selective serotonin reuptake inhibitors. The poor tolerability profile of the old tricyclics was explained by differences in drop-outs for side-effects, but not for inefficacy.

REVIEWER'S CONCLUSIONS

Whilst selective serotonin reuptake inhibitors do appear to show an advantage over tricyclic drugs in terms of total drop-outs, this advantage is relatively modest. This has implications for pharmaco-economic models, some of which may have overestimated the difference of drop-out rates between selective serotonin reuptake inhibitors and tricyclic antdepressants. These results are based on short-term randomised controlled trials, and may not generalise into clinical practice.

Gene-enhanced tissue engineering: applications for wound healing using cultured dermal fibroblasts transduced retrovirally with the PDGF-B gene

The treatment of difficult wounds remains a considerable clinical challenge. The goal of this study was to determine whether genetic augmentation of dermal cells on resorbable matrices can stimulate the healing process, leading to increased tissue repair in a rat full-thickness excisional wound repair model. The human platelet-derived growth factor B (PDGF-B) gene was the initial gene chosen to test this hypothesis. The human PDGF-B gene was obtained from human umbilical vein endothelial cells (HUVEC) by reverse transcriptase-polymerase chain reaction, cloned into retroviral vectors under control of either the cytomegalovirus promoter or the rat beta-actin promoter, and introduced into primary rat dermal cells. In vitro results demonstrate that rat dermal cells are transduced and selected readily using retroviral vectors, and engineered to secrete PDGF-B at a steady-state level of approximately 2 ng per milliliter culture per 1 million cells per 24 hours. Seeding of the gene-modified cells onto polyglycolic acid (PGA) scaffold matrices and introduction into the rat model resulted in substantially increased fibroblast hypercellularity over control wounds at both 7 and 14 days posttreatment. Our results demonstrate that gene augmentation of rat dermal fibroblasts with the PDGF-B gene introduced into this animal model via PGA matrices modulates wound healing and suggests that experimentation with additional genes for use separately or in combination with PDGF-B for additional, improved wound healing is warranted.

Human serum-resistant retroviral vector particles from galactosyl (alpha1-3) galactosyl containing nonprimate cell lines

Retroviral vector particles (RVP) which are resistant to inactivation by human serum will be needed for many in vivo gene therapy applications. Murine-based producer cell lines generate RVP which are inactivated by human serum, reportedly due to the presence of the galactosyl (alpha1-3) galactosyl carbohydrate moiety (alphaGal) on these and other nonprimate producer cells and RVP. Consequently, human cells (which lack the alphaGal moiety) have been developed as producer cell lines for generation of human serum-resistant RVP. In this study, we report that contrary to earlier reports, the presence of the alphaGal moiety on producer cells and RVP does not necessarily correlate with cell killing or RVP inactivation by human serum. We show that the alphaGal-positive ferret brain cell line, Mpf, is an excellent basal cell line for generation of RVP which have titers and serum resistance levels equal to or greater than RVP produced in human cell lines such as HT1080. Therefore, packaging cell lines need not be limited to those of human or primate origin for production of human serum-resistant RVP.