Chondrocytes Directly Transform into Bone Cells in Mandibular Condyle Growth

For decades, it has been widely accepted that hypertrophic chondrocytes undergo apoptosis prior to endochondral bone formation. However, very recent studies in long bone suggest that chondrocytes can directly transform into bone cells. Our initial in vivo characterization of condylar hypertrophic chondrocytes revealed modest numbers of apoptotic cells but high levels of antiapoptotic Bcl-2 expression, some dividing cells, and clear alkaline phosphatase activity (early bone marker). Ex vivo culture of newborn condylar cartilage on a chick chorioallantoic membrane showed that after 5 d the cells on the periphery of the explants had begun to express Col1 (bone marker). The cartilage-specific cell lineage-tracing approach in triple mice containing Rosa 26(tdTomato) (tracing marker), 2.3 Col1(GFP) (bone cell marker), and aggrecan Cre(ERT2) (onetime tamoxifen induced) or Col10-Cre (activated from E14.5 throughout adult stage) demonstrated the direct transformation of chondrocytes into bone cells in vivo. This transformation was initiated at the inferior portion of the condylar cartilage, in contrast to the initial ossification site in long bone, which is in the center. Quantitative data from the Col10-Cre compound mice showed that hypertrophic chondrocytes contributed to ~80% of bone cells in subchondral bone, ~70% in a somewhat more inferior region, and ~40% in the most inferior part of the condylar neck (n = 4, P < 0.01 for differences among regions). This multipronged approach clearly demonstrates that a majority of chondrocytes in the fibrocartilaginous condylar cartilage, similar to hyaline cartilage in long bones, directly transform into bone cells during endochondral bone formation. Moreover, ossification is initiated from the inferior portion of mandibular condylar cartilage with expansion in one direction.

New insights into implication of the SLIT/ROBO pathway in the prehierarchical follicle development of hen ovary

The SLIT/Roundabout (ROBO) pathway is involved in follicle development of mammalian ovary, and 2 secreted hormones activin A and inhibin A have potential roles in modulation of the SLIT/ROBO system, but the related actions remain poorly understood in bird. The aims of the present study were to examine the spatial and temporal expression of the SLIT ligand genes (SLIT1, SLIT2, and SLIT3) and their receptor ROBO1, ROBO2, ROBO3, and ROBO4 genes in various-sized prehierarchical follicles during hen ovary development and the effects of activin A and inhibin A on the expression of these genes in the cultured hen follicles. Our result demonstrated that the transcripts of the 3 SLIT genes were highly expressed in the developing follicles and expression patterns of the SLIT transcripts were different from those of ROBO genes detected by real-time quantitative reverse transcriptase PCR. Both SLIT and ROBO transcripts were predominantly expressed in oocytes and granulosa cells from the prehierarchichal follicles examined by in situ hybridization. The localization for SLIT and ROBO proteins was revealed by immunohistochemistry similar to the spatial distribution of their transcript. In cultured follicles (4 to 8 mm in diameter), the expression levels of SLIT and ROBO members are hormonally regulated by activin A (10 ng/mL) and/or inhibin A (20 ng/mL) after treatment for 24 h. However, the expression of only SLIT2, SLIT3, and ROBO3 mRNA presented a directly opposite response to activin A and inhibin A hormones. These results indicate that SLIT/ROBO pathway is implicated in the prehierarchical follicular development of the hen ovary by an intrafollicular autocrine and/or paracrine action, and is influenced by activin A and inhibin A hormones.

Comparison of hospital length of stay between hospitalized non-valvular atrial fibrillation patients treated with either apixaban or warfarin

BACKGROUND

Hospital length of stay (LOS) is an important cost driver for hospitals and payers alike. Hospitalized non-valvular atrial fibrillation (NVAF) patients treated with apixaban may have shorter LOS than those treated with warfarin because of the absence of need for INR monitoring in apixaban. Thus, this study compared hospital LOS between hospitalized NVAF patients treated with either apixaban or warfarin.

METHODS

This was a retrospective, observational cohort study based on a large US database including diagnosis, procedure, and drug administration information from >600 acute-care hospitals. Patients selected for study were aged ≥18 years and had a hospitalization record with an ICD-9-CM diagnosis code for atrial fibrillation (AF) in any position from 1 January 2013 to 28 February 2014 (index hospitalization). Patients with diagnoses indicative of rheumatic mitral valvular heart disease or a valve replacement procedure during index hospitalization were excluded. Patients were required to have been treated with either apixaban or warfarin, and not treated with rivaroxaban or dabigatran, during index hospitalization. Apixaban patients were propensity score (PS) matched to warfarin patients at a 1:1 ratio, using patient demographic/clinical and hospital characteristics. The study outcome was hospital LOS, calculated as discharge date minus admission date; a sensitivity analysis calculated hospital LOS as discharge date minus first anticoagulant administration date. Sub-analyses were conducted among patients with a primary diagnosis of AF.

RESULTS

The study included 832 apixaban patients matched to 832 warfarin patients. Mean [standard deviation (SD)] and median hospital LOS were significantly (p < 0.001) shorter in apixaban patients (4.5 [4.2] and 3 days) than in warfarin patients (5.4 [5.0] and 4). Results were consistent in the sensitivity and sub-analyses.

CONCLUSIONS

Among NVAF patients, apixaban treatment was associated with shorter hospital LOS when compared with warfarin treatment. These findings may have important clinical and economic implications for hospitals, payers, and patients.

Inhalation of recombinant adenovirus expressing granulysin protects mice infected with Mycobacterium tuberculosis

Granulysin is a cytolytic molecule with perforin and granzymes that is expressed by activated human CTLs, NK and γδ T cells, and it has broad antimicrobial activity, including to drug-sensitive and drug-resistant Mycobacterium tuberculosis. We hypothesized that approaches facilitating the expression of granulysin in M. tuberculosis-infected host cells in the lung may provide a novel treatment strategy for pulmonary TB. In this study, a recombinant replication-deficient adenovirus serotype 5-based rAdhGLi was constructed that expressed human granulysin in the cytosol of the U937 and RAW264.7 macrophage-like cell lines as confirmed by western blotting and co-localization technology using indirect immunofluorescence staining. Ninety-six hours after both cell lines were infected with M. tuberculosis, acid-fast staining and enumeration demonstrated that rAdhGLi-treated cells had a lower colony-forming units (CFU) of intracellular bacteria than culture medium or AdNull controls. Granulysin was only expressed in the lung and not in other organs following inhalation of rAdhGLi. In particular, immunocompetent BALB/c mice or SCID mice intranasally infected with ~200 CFU of virulent M. tuberculosis H37Rv intranasally were treated with rAdhGLi, and they showed decreased bacterial loads in the lung when compared with phosphate-buffered saline or AdNull controls. Importantly, a clear dose-dependent rAdhGLi treatment efficacy was found in infected BALB/c mice, with the most significant reduction in lung bacteria obtained in BALB/c mice treated with 10(9) plaque-forming units of rAdhGLi without any pathological changes. Our study indicates that rAdhGLi may be used as a novel and efficient treatment strategy with the capability to directly kill intracellular M. tuberculosis.

Sorafenib combined with percutaneous radiofrequency ablation for the treatment of medium-sized hepatocellular carcinoma

OBJECTIVE

Sorafenib, an oral multikinase inhibitor, is the proved therapy method for patients with advanced hepatocellular carcinoma (HCC). Based on heat delivery, Radiofrequency ablation (RFA) has been found to achieve complete neoplasm necrosis. It is the most widely performed percutaneous therapy for HCC. However, Study associated combined Sorafenib with RFA therapy for patients with advanced HCC has never been reported. The aim of present study is to explore the efficacy and safety of sorafenib combined with RFA therapy for the patients with medium-sized HCC.

PATIENTS AND METHODS

A total of 62 patients diagnosed as HCC were involved in this study. All patients were randomly assigned to sorafenib and RFA (n=30) or RFA-alone (n=32) treatment groups. Treatment outcomes, including recurrence rates, time to progression (TTP) and adverse reactions induced by sorafenib were observed and recorded to assess the efficacy and safety of the combination method.

RESULTS

During the overall follow-up period, the recurrence rate of the combination subgroup was 56.7% (17/30), and that of the RFA-alone subgroup was 87.5% (28/32) (p < 0.01). The median TTP was 17.0 months in the combination therapy vs. 6.1 months in the RFA-alone (p < 0.05). Hand-foot skin reactions were reported by 83.3% (25/30) of patients and 46.7% (14/30) reported diarrhea while the most adverse events (AEs) were mild to moderate in the combination subgroup.

CONCLUSIONS

Sorafenib combined with RFA significantly decreased recurrence rates and prolonged the survival time of medium-sized HCC patients. The combination therapy is safer and more effective than the control without unexpected side effects. Furthermore, the earlier application, the better results were.

Evaluation of medical costs associated with use of new oral anticoagulants compared with standard therapy among venous thromboembolism patients

OBJECTIVE

This study evaluated differences in medical costs associated with clinical end-points from randomized clinical trials that compared the new oral anticoagulants (NOACs), dabigatran, rivaroxaban, apixaban, and edoxaban, to standard therapy for treatment of patients with venous thromboembolism (VTE).

RESEARCH DESIGN AND METHODS

Event rates of efficacy and safety end-points from the clinical trials (RE-COVER, RE-COVER II, EINSTEIN-Pooled, AMPLIFY, Hokusai-VTE trial) were obtained from published literature. Incremental annual medical costs among patients with clinical events from a US payer perspective were obtained from the literature or healthcare claims databases and inflation adjusted to 2013 costs. Differences in total medical costs associated with clinical end-points for the NOACs vs standard therapy were then estimated. One-way and Monte Carlo sensitivity analyses were carried out.

RESULTS

A lower rate of major bleedings was associated with use of any of the NOACs vs standard therapy. Except for dabigatran, use of NOACs was also associated with a lower rate of recurrent VTE/death. As a result of the reduction in clinical event rates, the overall medical cost differences were -$146, -$482, -$918, and -$344 for VTE patients treated with dabigatran, rivaroxaban, apixaban, and edoxaban, respectively, vs patients treated with standard therapy.

CONCLUSIONS

When any of the four NOACs are used instead of standard therapy for acute VTE, treatment medical costs are reduced. Apixaban is associated with the greatest reduction in medical costs, which is driven by medical cost reductions associated with both efficacy and safety end-points. Further evaluation may be needed to validate these results in the real-world setting.

Osterix couples chondrogenesis and osteogenesis in post-natal condylar growth

Osterix (Osx) is a transcription factor essential for osteoblast differentiation and bone mineralization. Although there are indications that Osx also plays a regulatory role in cartilage, this has not been well-studied. The goal of this study was to define the function of Osx in the post-natal growth of the secondary cartilage at the mandibular condyle. Conditional Osx knockout (cKO) mice that were missing Osx only in cartilage were generated by crossing Osx-loxP mice to Aggrecan-Cre mice. Cre activity was induced by tamoxifen injection twice a week from day 12 to 1 mo of age, and specimens were collected at 1 and 5 mo of age. At 1 mo of age, the condylar hypertrophic chondrocyte zone in the cKO-mice was > three-fold thicker than that in the age-matched control, with little sign of endochondral bone formation. Immunohistochemistry and analysis of histological data revealed a defect in the coupling of chondrogenesis and osteogenesis in the cKO mice. In five-month-old mice examined to address whether late-stage removal of the Cre-deletion event would alleviate the phenotype, the hypertrophic chondrocyte zone in the cKO condyles was considerably larger than in wild-type mice. There were large discrete areas of calcified cartilage in the hypertrophic zone, few signs of endochondral bone formation, and large regions of disorganized intramembranous bone. Analysis of these data further strengthens the notion that Osterix is essential for the coupling of terminal cartilage differentiation and endochondral ossification in mandibular condylar cartilage.

Medical Costs of Oral Anticoagulants vs Warfarin for Atrial Fibrillation Patients with Different Stroke Risks

INTRODUCTION

The Apixaban for the Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE), Randomized Evaluation of Long-term Anticoagulation Therapy (RE-LY), and Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET-AF) trials demonstrated that the oral anticoagulants (OACs), apixaban, dabigatran, and rivaroxaban, respectively, are efficacious for stroke prevention among nonvalvular atrial fibrillation (NVAF) patients. Based on clinical trial results this study evaluated medical costs of clinical events associated with use of individual OACs relative to those of warfarin in NVAF patients with moderate and high stroke risk.

METHODS

Rates for primary and secondary efficacy and safety outcomes (i.e., clinical events) among NVAF patients with CHADS2 = 2 and ≥3 were determined from the three OAC trials. One-year incremental costs among patients with clinical events from a US payer perspective were obtained from the literature and inflation adjusted to 2010 costs. Medical costs for clinical events associated with each OAC vs. warfarin were estimated and compared.

RESULTS

For NVAF patients with moderate stroke risk (CHADS2 = 2) differences in clinical event medical costs vs. warfarin were -$298, -$143, and +$117 per patient year for apixaban, dabigatran (150 mg), and rivaroxaban, respectively (negative numbers indicate cost reduction). For NVAF patients with high stroke risk (CHADS2 ≥ 3) differences in clinical event medical costs vs. warfarin were -$697, +$2, and -$100 for apixaban, dabigatran (150 mg), and rivaroxaban, respectively.

CONCLUSIONS

Medical cost differences associated with OACs vs. warfarin vary according to stroke risk. Of the three OACs, apixaban demonstrated consistent medical cost reductions vs. warfarin for NVAF patients with moderate and high stroke risks.

A novel way to statistically analyze morphologic changes in Dmp1-null osteocytes

Recent studies have revealed multiple roles of osteocytes in bone metabolism. However, detailed analyses of the embedded osteocytes in bone structure are still limited because of the high mineral content around these cells. In this study, we developed an innovative technique, the "FITC-Imaris technique", which combines FITC ([2, 5]-Fluorescein isothiocyanate), confocal microscopy and Imaris software. With this method, we could not only visualize the 3-D morphology of embedded osteocytes, but more importantly, we were able to statistically quantitate the osteocyte structure in the cell surface area, total cell volume, and dendrite numbers. Furthermore, we made a side-by-side comparison of the new method with the acid-etched SEM imaging technique, a common imaging method for studies of osteocyte morphology with a much smaller cell depth (< 3 μm). Finally, we used the FITC-Imaris technique to show both the morphological and statistical differences in the osteocyte structure between the Dmp1-null mice (the osteomalacia model) and their age-matched control littermates. We expect that this newly developed technique will become a powerful tool to disclose more roles that osteocytes play in bone health and diseases.

Depression monitoring and patient behavior in the Clinical Outcomes in MEasurement-Based Treatment (COMET) trial

OBJECTIVE

In this secondary analysis of results of the Clinical Outcomes in MEasurement-Based Treatment (COMET) trial, patient behaviors that might account for the differences observed in clinical outcomes were examined.

METHODS

Patients (N=914) diagnosed as having major depressive disorder participated in telephone interviews either monthly for six months (intervention) or at three and six months (usual care) asking about antidepressant medication-taking, use of psychotherapy or counseling, and participation in depression support groups. Physicians (N=83) in the intervention arm received monthly feedback regarding their patients' depression severity.

RESULTS

A total of 664 (73%) patients completed the month 6 interview. The adjusted odds of current antidepressant use at six months were 85% greater (p=.01) for patients in the intervention (N=380) versus usual care (N=284) arms, according to multivariate regression analyses.

CONCLUSIONS

More frequent measurement of depression symptoms was associated with greater medication persistence, which in turn may have mediated clinical improvements.

Abstract 301: Evaluation Of Net Clinical Benefits Of New Oral Anticoagulants Used For Acute Venous Thromboembolism Treatment vs. Standard Therapy

Background: Venous thromboembolism (VTE) is a significant healthcare burden, but is a preventable and treatable condition. The new oral anticoagulants (NOACs), apixaban, rivaroxaban, dabigatran, and edoxaban have all been shown in phase III trials to be noninferior in efficacy to standard therapies for acute VTE treatment, although there may be some differences in the bleeding rates among the NOACs. This study evaluated the net clinical benefits (NCB) of NOACs vs. standard therapies based on the AMPLIFY, EINSTEIN-Pooled analysis, RECOVER-1, RE-COVER II, and Hokusai-VTE trial results.

Methods: Event rates of the primary efficacy and safety outcomes, as defined in each original trial, among VTE patients during trial periods were obtained from the published clinical trial data. Data from RECOVER-I and -II trials were combined to represent the findings for dabigatran since the two trials were of similar design. EINSTEIN-pooled (DVT and PE combined) data were used to represent findings for rivaroxaban. The combinations of rates for the primary efficacy endpoint, representing recurrent VTE or death and major bleedings (MB) were evaluated and defined as the NCB of each NOAC. Additionally, the number of VTE patients needed to treat (NNT) to avoid one event (e.g. VTE or MB) with each NOAC was also determined.

Results: For patients treated in the VTE clinical trials, the differences in event rates of recurrent VTE or death for apixaban, rivaroxaban, dabigatran, and edoxaban vs. standard therapy were -0.43%, -0.23%, 0.20%, and -0.34%, respectively. The differences in event rates of MB for apixaban, rivaroxaban, dabigatran, and edoxaban vs. standard therapy were -1.26%, -0.78%, -0.43%, and -0.24%, respectively. The NCB improved for all NOAC treated patients, with those treated with apixaban (-1.69%) vs. standard therapy having the greatest NCB, followed by those treated with rivaroxaban (-1.01%), edoxaban (-0.58%), and dabigatran ( -0.23%) (Table 1).

Conclusions: All NOACs were shown to be non-inferior to standard VTE treatments in clinical trials; however, apixaban may provide the optimal NCB with the lowest NNT. How these results translate into real-world outcomes or medical cost reductions will require further evaluation.

Comparison of Medical Costs of Patients With Atrial Fibrillation Unsuitable for Warfarin Treatment With Apixaban or Aspirin Based on AVERROES Trial

Background:

The AVERROES trial name is the following: The Apixaban Versus Acetylsalicylic Acid (ASA) to Prevent Stroke in Atrial Fibrillation Patients Who Have Failed or Are Unsuitable for Vitamin K Antagonist Treatment (AVERROES) trial demonstrated that apixaban reduced the risk of stroke relative to aspirin, without significantly increasing major bleeding risk in patients with atrial fibrillation (AF) considered unsuitable for warfarin therapy. Based on AVERROES trial results, this study compared the medical costs for clinical end points among patients with AF treated with either apixaban or aspirin.

Methods:

Medical costs per patient-year for clinical events were determined. Based on clinical event rates for patients in the AVERROES trial, medical costs excluding drug costs were estimated for apixaban- and aspirin-treated patient groups.

Results and Conclusions:

Based on AVERROES trial results, among patients with AF unsuitable for warfarin therapy, apixaban use was estimated to be associated with a mean medical cost avoidance of US$735 in a patient-year relative to aspirin. The primary driver was the significant reduction in ischemic stroke rate. The medical cost reduction associated with apixaban use was consistent in sensitivity analyses.

Medical costs in the US of clinical events associated with oral anticoagulant (OAC) use compared to warfarin among non-valvular atrial fibrillation patients ≥75 and <75 years of age, based on the ARISTOTLE, RE-LY, and ROCKET-AF trials

OBJECTIVES

Based on clinical trials the oral anticoagulants (OACs) apixaban, dabigatran, and rivaroxaban are efficacious for reducing stroke risk for non-valvular atrial fibrillation (NVAF) patients. Based on the clinical trials, this study evaluated the medical costs for clinical events among NVAF patients ≥75 and <75 years of age treated with individual OACs vs warfarin.

METHODS

Rates for primary and secondary efficacy and safety outcomes (i.e., clinical events) among NVAF patients receiving warfarin or each of the OACs were determined for NVAF populations aged ≥75 years and <75 years of age from the OAC vs warfarin trials. One-year incremental costs among patients with clinical events were obtained from published literature and inflation adjusted to 2010 costs. Medical costs, excluding medication costs, for clinical events associated with each OAC and warfarin were then estimated and compared.

RESULTS

Among NVAF patients aged ≥75, compared to warfarin, use of either apixaban or rivaroxaban was associated with a reduction in medical costs per patient year (apixaban = -$825, rivaroxaban =-$23), while dabigatran use was associated with increased medical costs of $180 per patient year. Among NVAF patients <75 years of age medical costs per patient year were estimated to be reduced -$254, -$367, and -$88, for apixaban, dabigatran, and rivaroxaban, respectively, in comparison to warfarin.

LIMITATIONS

This economic analysis was based on clinical trial data and, therefore, the direct application of the results to routine clinical practice will require further assessment.

CONCLUSIONS

Difference in medical costs between OAC and warfarin treated NVAF patients vary by age group and individual OACs. Although reductions in medical costs for NVAF patients aged ≥75 and <75 were observed for those using either apixaban or rivaroxaban vs warfarin, the reductions were greater per patient year for both the older and younger NVAF populations using apixaban.

Abstract 12: Evaluation of Medical Costs Associated with Use of Novel Oral Anticoagulants Compared with Warfarin Among Nonvalvular Atrial Fibrillation Patients with Moderate and High Stroke Risk

Background: Nonvalvular atrial fibrillation (NVAF) is a sustained cardiac rhythm disturbance, which increases stroke risk up to 5-fold and affects more than 5 million Americans. Warfarin is efficacious for reducing stroke risk among NVAF patients, but its use is complicated by it having a narrow therapeutic range, significant drug-drug interactions, and an increased risk of major bleeding. The ARISTOTLE, RE-LY, and ROCKET-AF clinical trials demonstrated the novel oral anticoagulants (NOACs), apixaban, dabigatran, and rivaroxaban, respectively are efficacious for stroke prevention among NVAF patients. This study evaluated medical costs of clinical events associated with the use of individual NOACs relative to that of warfarin among NVAF patients with moderate and high stroke risk.

Methods: Rates for primary and secondary efficacy and safety outcomes (i.e. clinical events) per year among NVAF patients with CHADS 2 =2 and ≥ 3 were obtained or estimated from the 3 NOAC clinical trials. One year incremental costs among patients with clinical events from a US payer perspective were obtained from the literature and inflation adjusted to 2010 costs. Differences in medical costs for clinical events associated with use of individual NOACs instead of warfarin were then estimated.

Results: For NVAF patients with moderate stroke risk (CHADS 2 =2), the overall differences in medical costs for clinical events relative to warfarin were $298, $143, and +$117 per patient year for apixaban, dabigatran (150 mg), and rivaroxaban, respectively (negative numbers=cost reduction). For NVAF patients with high stroke risk (CHADS 2 ≥ 3) the overall differences in medical costs for clinical events relative to warfarin were $697, $2, and $100 for apixaban, dabigatran (150 mg), and rivaroxaban, respectively.

Conclusions: Of the three NOACs, apixaban demonstrated greater medical cost reductions relative to warfarin among NVAF patients at moderate and high stroke risk. The medical cost reduction associated with apixaban use instead of warfarin was greater for NVAF patients at higher stroke risk vs. those at moderate stroke risk and was driven primarily by higher absolute reductions in clinical event rates for major bleeding, stroke and systemic embolism.

Abstract 265: Impact of Bleeding on Length of Stay and Inpatient Cost Among Atrial Fibrillation Patients Hospitalized for Congestive Heart Failure

OBJECTIVES: To determine the impact of hospital acquired bleeding in atrial fibrillation (AF) patients admitted for congestive heart failure (CHF) on length of stay (LOS) and total hospitalization cost.

METHODS: The Premier research database was queried to identify adult inpatients discharged between 2008 and 2011 with a primary diagnosis code of CHF and a secondary code of AF in whom bleeding was not present on admission. Bleeding was identified using ICD-9 diagnosis codes or charge codes for fresh frozen plasma, blood, or transfusion of blood or blood components. In univariate comparisons of patients with and without bleeding, t-tests for continuous variables and chi-squared tests for categorical variables were used (alpha = 0.05). Gamma regression adjusting for demographics, comorbidities and antiplatelet/anticoagulant use were utilized to produce estimates for mean LOS and total hospitalization cost among patients with and without bleeding.

RESULTS: There were 76,245 patients, average age of 77.4 (SD 11.8) that met the study criteria. Across the entire population, mean LOS was 5.74 (SD 4.54) days, and mean total cost was $11,963 (SD 14,852). Overall, 4,159 (5.5%) patients had a bleed during their hospitalization. After adjustment, the mean estimated LOS was 9.49 (95% CI 9.30-9.68) days in the bleed group and 5.40 (95% CI 5.37-5.42) days in the no bleed group. The adjusted mean estimated total hospitalization cost was greater in the bleed group $21,941 (95% CI 21,425-22,467) vs. $10,757 (95% CI 10,696-10,817) in the no bleed group. Sensitivity analyses adjusting for cardiac related procedures resulted in numerical differences in the estimates, but not the direction or significance of the outcomes.

CONCLUSIONS: Occurrence of hospital acquired bleeding in AF patients with CHF is associated with a significant increase in the LOS and total hospitalization cost. In this study, adjustment for demographic and comorbidity differences as well as the use of antiplatelets and anticoagulants did not change the magnitude or direction of these associations, though residual confounding cannot be ruled out. In this cohort, bleeding was associated with approximately additional $47 million dollars in cost and 17,000 additional hospital days.

Exposure to potentially dangerous drug-drug interactions involving antipsychotics

OBJECTIVE

Antipsychotic drug therapy is the cornerstone of treatment of persons with schizophrenia. Because most antipsychotics are metabolized by the hepatic cytochrome P450 system, concomitant use of an antipsychotic and medications that are competitively metabolized by the same system may cause a potentially harmful drug-drug interaction. This study used a large state's Medicaid claims database to examine the proportion of patients exposed to such interactions and the risk factors associated with exposure.

METHODS

Claims from January 2000 through December 2003 for adult patients with a diagnosis of schizophrenia and at least one prescription for an antipsychotic (N=27,909) were examined for pairs of medications identified as potentially causing moderate or severe adverse drug effects. Logistic regression models were estimated to determine potential risk factors associated with exposure to the interaction pairs.

RESULTS

A total of 6,417 (23%) patients were exposed to 14,213 potentially harmful interactions; 4,725 patients had at least one exposure from the same pharmacy, and 4,032 patients were exposed by the same physician. The greatest number of exposures (N=1,353) to potentially harmful combinations involved olanzapine and haloperidol. Patients prescribed risperidone were most likely to be exposed to an interaction (13.1%), followed by patients prescribed olanzapine (10.3%), quetiapine (3.3%), and clozapine (3.2%). A higher risk of exposure was associated with being female (odds ratio [OR]=.94), being white (OR=1.43), having depression (OR=1.21), or having impulse-control disorder (OR=1.98).

CONCLUSIONS

Interventions by physicians and pharmacies to reduce the prescribing and dispensing of potentially harmful pairs of medications to patients with schizophrenia are recommended.

Clinical Outcomes in Measurement-based Treatment (Comet): a trial of depression monitoring and feedback to primary care physicians

BACKGROUND

Despite the availability of effective treatments for depression, many patients under the care of primary care physicians do not achieve remission. Clinical Outcomes in Measurement-based Treatment (COMET) was designed to assess whether communicating patient-reported depression symptom severity to primary care physicians affects patient outcomes at 6 months.

METHODS

Nine hundred fifteen patients (intervention: n = 503; control: n = 412) diagnosed with major depressive disorder were enrolled in a prospective trial in which physician practice sites were assigned to either the intervention or control study arm. Only patients who were prescribed an antidepressant by their physician were eligible, but medication type was independent of the study protocol. Intervention-arm physicians received monthly updates on their patients' depression severity, which was determined with the nine-item Patient Health Questionnaire (PHQ-9) administered during telephone interviews. Remission was defined as a PHQ-9 score <5 at 6 months; response was defined as a score reduction ≥50%.

RESULTS

Among patients with baseline PHQ-9 score ≥5, 45.0% achieved remission (46.7% intervention versus 42.8% control) and 63.9% responded (67.0% intervention versus 59.7% control) at 6 months. After adjusting for baseline demographic and clinical variables, odds of remission (odds ratio [OR], 1.59 [95% CI, 1.07-2.37]) or response (OR, 2.02 [95% CI, 1.36-3.02]) were significantly greater for the intervention group than for control patients.

CONCLUSIONS

This study demonstrated that regular patient symptom monitoring with feedback to physicians improved outcomes of depression treatment in the primary care setting. Determining reasons for the high observed nonremission rates requires further investigation.

Ageing alters behavioural function and brain arginine metabolism in male Sprague-Dawley rats

A growing body of evidence suggests the involvement of L-arginine and its metabolites in the ageing and neurodegenerative processes. The present study assessed behavioural performance in 4- (young), 12- (middle-aged) and 24- (aged) month-old male Sprague-Dawley rats, and investigated age-related changes in the activity of two key arginine metabolic enzymes, nitric oxide synthase (NOS) and arginase, and the levels of L-arginine and its downstream metabolites in a number of memory-related brain structures. Aged rats were less anxious and performed poorly in the water maze task relative to the young and middle-aged rats, and both middle-aged and aged rats displayed reduced exploratory activity relative to the young ones. There were significant age-related changes in NOS and arginase activities, and the levels of L-arginine, L-citrulline, L-ornithine, agmatine, putrescine, spermidine, spermine and glutamate, but not γ-aminobutyric acid, in the CA1, CA2/3 and dentate gyrus sub-regions of the hippocampus and the prefrontal, entorhinal, perirhinal, postrhinal and temporal (an auditory cortex) cortices in a region-specific manner. Cluster analyses revealed that the nine related neurochemical variables formed distinct groups, which changed as a function of ageing. Multiple regression analyses revealed a number of significant correlations between the neurochemical and behavioural variables. The present study further supports the involvement of arginine metabolism in the ageing process, and provides further evidence of the effects of animals' behavioural experience on arginine metabolism.