Safety and patient outcomes with lubiprostone for up to 52 weeks in patients with irritable bowel syndrome with constipation

BACKGROUND

Irritable bowel syndrome with constipation (IBS-C) significantly decreases quality of life and the ability to perform daily living activities.

AIM

To demonstrate the long-term safety, tolerability and patient outcomes of lubiprostone in patients with IBS-C.

METHODS

This extension study enrolled 522 IBS-C patients who had completed one of two randomised phase 3 studies. All enrolled patients received open-label lubiprostone orally for 36-weeks (8 mcg, twice daily). The primary objective was the assessment of long-term safety and tolerability, monitored via adverse events (AEs), laboratory parameters and vital signs. Additional outcome endpoints included monthly responder rates and patient evaluations of IBS-C symptom severity and impact on quality of life.

RESULTS

The evaluable safety population comprised of 520 patients; 476 of which had patient reported outcome data available. The overall safety profile of lubiprostone during this study was similar to that observed in the preceding phase 3 studies. The most common AEs were diarrhoea (11.0%), nausea (11.0%), urinary tract infection (9.0%), sinusitis (9.0%) and abdominal distention (5.8%). Diarrhoea and nausea were the most common treatment-related AEs. No serious AEs were considered treatment-related. Seventeen patients discontinued due to a treatment-related AE, of which diarrhoea and nausea accounted for six (1.2%) and three (0.6%) respectively. For responder rates and patient-evaluated parameters (n = 476), all groups experienced significant improvements from baseline, with initial improvements maintained throughout the study.

CONCLUSION

In patients with irritable bowel syndrome with constipation, lubiprostone 8 mcg twice daily was found to be safe and well tolerated over 9-13 months of treatment.

An activating mutation of AKT2 and human hypoglycemia

Pathological fasting hypoglycemia in humans is usually explained by excessive circulating insulin or insulin-like molecules or by inborn errors of metabolism impairing liver glucose production. We studied three unrelated children with unexplained, recurrent, and severe fasting hypoglycemia and asymmetrical growth. All were found to carry the same de novo mutation, p.Glu17Lys, in the serine/threonine kinase AKT2, in two cases as heterozygotes and in one case in mosaic form. In heterologous cells, the mutant AKT2 was constitutively recruited to the plasma membrane, leading to insulin-independent activation of downstream signaling. Thus, systemic metabolic disease can result from constitutive, cell-autonomous activation of signaling pathways normally controlled by insulin.

The nested structure of cancer symptoms. Implications for analyzing co-occurrence and managing symptoms

OBJECTIVE

Although many cancer patients experience multiple concurrent symptoms, most studies have either focused on the analysis of single symptoms, or have used methods such as factor analysis that make a priori assumptions about how the data is structured. This article addresses both limitations by first visually exploring the data to identify patterns in the co-occurrence of multiple symptoms, and then using those insights to select and develop quantitative measures to analyze and validate the results.

METHODS

We used networks to visualize how 665 cancer patients reported 18 symptoms, and then quantitatively analyzed the observed patterns using degree of symptom overlap between patients, degree of symptom clustering using network modularity, clustering of symptoms based on agglomerative hierarchical clustering, and degree of nestedness of the symptoms based on the most frequently co-occurring symptoms for different sizes of symptom sets. These results were validated by assessing the statistical significance of the quantitative measures through comparison with random networks of the same size and distribution.

RESULTS

The cancer symptoms tended to co-occur in a nested structure, where there was a small set of symptoms that co-occurred in many patients, and progressively larger sets of symptoms that co-occurred among a few patients.

CONCLUSIONS

These results suggest that cancer symptoms co-occur in a nested pattern as opposed to distinct clusters, thereby demonstrating the value of exploratory network analyses to reveal complex relationships between patients and symptoms. The research also extends methods for exploring symptom co-occurrence, including methods for quantifying the degree of symptom overlap and for examining nested co-occurrence in co-occurrence data. Finally, the analysis also suggested implications for the design of systems that assist in symptom assessment and management. The main limitation of the study was that only one dataset was considered, and future studies should attempt to replicate the results in new data.

A reappraisal of intra-articular corticosteroid therapy in juvenile idiopathic arthritis

Intraarticular corticosteroid (IAC) injection is a safe and rapidly effective treatment for synovitis in children with juvenile idiopathic arthritis (JIA). This procedure can be performed in an ambulatory care setting using local anaesthesia, with or without conscious sedation. Younger children, or those candidate to multiple injections, require general anaesthesia. Triamcinolone hexacetonide is the optimal corticosteroid preparation. However, for smaller joints or joints that are not easy to assess clinically, use of a more soluble corticosteroid drug is advised. Imaging guidance may facilitate accurate placement of the needle within the joint space. Use of ultrasound for this purpose has gained increasing popularity in the recent years. IAC injections are used most frequently to treat oligoarthritis, but the strategy of performing multiple IAC injections to induce disease remission, while simultaneously initiating therapy with second-line or biologic agents, has been proposed also for children with polyarticular JIA. However, the current place of IAC therapy in the management of children with JIA is uncertain due to the lack of controlled studies. Furthermore, it is still unknown whether this therapy has a disease-modifying effect over the long-term. This review summarises the present information about the use of IAC therapy in children with JIA.

Linezolid in the treatment of multidrug-resistant tuberculosis

BACKGROUND

Linezolid is a new antibiotic with activity against Mycobacterium tuberculosis in vitro and in animal studies. Several small case series suggest that linezolid is poorly tolerated because of the side effects of anemia/thrombocytopenia and peripheral neuropathy. To characterize our clinical experience with linezolid, the California Department of Public Health Tuberculosis Control Branch's Multidrug-Resistant Tuberculosis (MDR-TB) Service reviewed cases in which the MDR-TB treatment regimens included linezolid therapy.

METHODS

Record review was performed for 30 patients treated with linezolid as part of an MDR-TB regimen. Data were collected on clinical and microbiological characteristics, linezolid tolerability, and treatment outcomes. The dosage of linezolid was 600 mg daily. Vitamin B6 at a dosage of 50-100 mg daily was used to mitigate hematologic toxicity.

RESULTS

During 2003-2007, 30 patients received linezolid for the treatment of MDR-TB. Patients had isolates resistant to a median of 5 drugs (range, 2-13 drugs). Of the 30 cases, 29 (97%) were pulmonary; of these 29, 21 (72%) had positive results of acid-fast bacilli smear, and 16 (55%) were cavitary. Culture conversion occurred in all pulmonary cases at a median of 7 weeks. At data censure (31 December 2008), 22 (73%) of 30 patients had successfully completed treatment. Five continued to receive treatment. There were no deaths. Three patients had a poor outcome, including 2 defaults and 1 treatment failure. Side effects occurred in 9 patients, including peripheral and optic neuropathy, anemia/thrombocytopenia, rash, and diarrhea. However, only 3 patients stopped linezolid treatment because of side effects.

CONCLUSIONS

Linezolid was well tolerated, had low rates of discontinuation, and may have efficacy in the treatment of MDR-TB.

The Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND): test development and reliability

The motor skills of patients with spinal muscular atrophy, type I (SMA-I) are very limited. It is difficult to quantify the motor abilities of these patients and as a result there is currently no validated measure of motor function that can be utilized as an outcome measure in clinical trials of SMA-I. We have developed the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders ("CHOP INTEND") to evaluate the motor skills of patients with SMA-I. The test was developed following the evaluation of 26 infants with SMA-I mean age 11.5 months (1.4-37.9 months) with the Test of Infant Motor Performance and The Children's Hospital of Philadelphia Test of Strength in SMA, a newly devised motor assessment for SMA. Items for the CHOP INTEND were selected by an expert panel based on item mean and standard deviation, item frequency distribution, and Chronbach's alpha. Intra-rater reliability of the resulting test was established by test-retest of 9 infants with SMA-I over a 2 month period; Intraclass correlation coefficient (ICC) (3,1)=0.96. Interrater reliability was by video analysis of a mixed group of infants with neuromuscular disease by 4 evaluators; ICC (3,4)=0.98 and in a group of 8 typically developing infants by 5 evaluators ICC (3,5)=0.93. The face validity of the CHOP INTEND is supported by the use of an expert panel in item selection; however, further validation is needed. The CHOP INTEND is a reliable measure of motor skills in patients with SMA-I and neuromuscular disorders presenting in infancy.

Cat scratch disease: a diagnostic conundrum

We report the case of a patient who presented to a clinic for evaluation of inguinal lymphadenopathy. Histology of the lymph nodes revealed micoabscess formation suggesting infection with Lymphogranuloma venereum (LGV) or Bartonella henselae--the causative agent in cat scratch disease (CSD). The patient recalled no preceding animal exposure. Clinical and serological findings initially suggested early LGV but convalescent serology supported CSD. This serves as an important reminder that B. henselae infection should be considered a cause of regional lymphadenopathy in individuals suspected of having LGV.

Single- versus multiple-item assessment of quality of life in patients with advanced cancer

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Background: The main objective of palliative cancer care is to improve quality of life (QOL). As multiple dimensions impact on the construct of QOL, multi-dimensional instruments are usually used in its measurement. These are time consuming and burdensome for repeated use. Recent authors have suggested that brief single-item global assessments can provide a reliable measure of QOL. We assessed the performance of the Edmonton Symptom Assessment System ‘feeling of well-being’ item (ESAS WB) using the Functional Assessment of Cancer Therapy - General (FACT-G) instrument as a gold standard. Methods: After obtaining IRB approval, we reviewed the data from 213 advanced cancer patients who had participated in six studies from March 2006 to June 2008 and determined the level of association between baseline ESAS WB and FACT-G total score and subscale domains (Physical (Pwb), Social/Family (Swb), Emotional (Ewb), and Functional (Fwb) Well-Being) and also the 9 ESAS symptom intensity scores using Spearman correlation coefficients. We also calculated the change between the baseline (T1) and second (T2) observations of ESAS WB and of FACT-G total score and determined their level of association using a Pearson correlation coefficient. In addition, we predicted the change in FACT-G as predicted by the change in ESAS WB score using regression analysis. Results: Mean age was 60 (SD 12) years and 48% were female. At T1, the Spearman correlation coefficient of ESAS WB and FACT-G was -0.48 (p<0.0001). Spearman correlation coefficients for ESAS WB and FACT-G subscale domains and ESAS symptom intensity scores were also highly significant (p<0.0001) for all physical and emotional symptoms (other than p=0.003 for nausea) except for FACT Swb (p=0.08). The Pearson correlation coefficient for difference between T1 and T2 in ESAS WB and FACT-G for 146 patients was -0.36 (p<0.0001). The regression analysis was highly significant (p<0.0001). The change in ESAS WB corresponding to FACT-G published minimally important difference (MID) was -0.24 for 3, -1.55 for 5, and -2.87 for 7, respectively. Conclusions: ESAS WB is a practical instrument for clinical use and best reflects the Pwb, Ewb and Fwb domains of FACT-G as compared to Swb.

No significant financial relationships to disclose.

Phase II trial of the oral PARP inhibitor olaparib (AZD2281) in BRCA-deficient advanced ovarian cancer

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Background: Olaparib (AZD2281; KU-0059436) is a novel, orally active PARP inhibitor that induces synthetic lethality in homozygous BRCA-deficient cells. A phase I trial identified 400 mg bd as the maximum tolerated dose (MTD) with an initial signal of efficacy in BRCA-deficient cancers (ASCO 2008; abst 5510). The primary aim of this study was to test the efficacy of olaparib in confirmed BRCA1/BRCA2 carriers with advanced chemotherapy-refractory ovarian cancer. The secondary aim was to assess the safety and tolerability profile in ovarian cancer patients with BRCA1/2 deficiency. Methods: In an international, multicenter, proof-of-concept, single-arm, phase II study, two patient (pt) sequential cohorts received continuous oral olaparib in 28-day cycles, initially at the MTD, 400 mg bd (33 pts), and subsequently at 100 mg bd (24 pts), a previously shown clinically active and PARP inhibitory dose. Eligibility criteria included confirmed genetic BRCA1/2 mutation and recurrent, measurable, incurable disease (previous chemotherapy, median 3 lines). The primary efficacy endpoint was best objective response rate (ORR; RECIST) post baseline. Change in CA125 was a secondary efficacy endpoint. All adverse events were reported using CTCAE v3. Results: At this interim analysis dated October 31, 2008, of 57 enrolled pts (39 BRCA1 deficient and 18 BRCA2 deficient), 33 were evaluable at 400 mg bd and 24 at 100 mg bd. The confirmed RECIST ORR was 33% at 400 mg bd and 12.5% at 100 mg bd. Clinical benefit rate (ORR and/or confirmed >50% decline in CA125) was 57.6% at 400 mg bd and 16.7% at 100 mg bd. Toxicity was mainly mild in severity, reflecting grade 1/2 nausea (44%); fatigue (35%); and anemia (14%). Grade 3 toxicity occurred infrequently, and comprised primarily nausea (7%) and leukopenia (5%). Conclusions: Oral olaparib is well tolerated and highly active in advanced, chemotherapy-refractory BRCA-deficient ovarian cancer, with greater activity seen at the higher dose. Toxicity in BRCA1/2 carriers was similar to that seen in non-carriers. This study provides positive proof of the concept of the activity and tolerability of genetically defined targeted therapy with olaparib in BRCA-deficient ovarian cancers.

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Diagnostic strategies used in primary care

The strategies used by general practitioners in making a diagnosis are being formally recognised; this article is the first in a series that will illustrate their application, and is accompanied by a case study (doi:10.1136/bmj.b1187)

Clinical trial: lubiprostone in patients with constipation-associated irritable bowel syndrome--results of two randomized, placebo-controlled studies

BACKGROUND

Effective treatments for irritable bowel syndrome with constipation (IBS-C) are lacking.

AIM

To assess the efficacy and safety of lubiprostone in IBS-C.

METHODS

A combined analysis was performed among 1171 patients with a Rome II diagnosis of IBS-C in two phase-3 randomized trials of lubiprostone 8 mcg vs. placebo twice daily for 12 weeks. Using a balanced seven-point Likert scale ranging from significantly relieved (+3), to significantly worse (-3), patients responded on their electronic diary to the question: 'How would you rate your relief of IBS symptoms over the past week compared to how you felt before you entered the study?'. The primary efficacy endpoint was the percentage of overall responders.

RESULTS

Using an intent-to-treat analysis with last observation carried forward, a significantly higher percentage of lubiprostone-treated patients were considered overall responders compared with those treated with placebo (17.9% vs. 10.1%, P=0.001). Patients treated with lubiprostone reported a similar incidence of adverse events to those treated with placebo.

CONCLUSIONS

The percentage of overall responders based on patient-rated assessments of IBS-C symptoms was significantly improved in patients treated with lubiprostone 8 mcg twice daily compared to those treated with placebo. Lubiprostone was well tolerated with a favourable safety profile.

Heat shock protein 101 effects in A. thaliana: genetic variation, fitness and pleiotropy in controlled temperature conditions

The Hsp100/ClpB heat shock protein family is ancient and required for high temperature survival, but natural variation in expression and its phenotypic effects is unexplored in plants. In controlled environment experiments, we examined the effects of variation in the Arabidopsis cytosolic AtHsp101 (hereafter Hsp101). Ten wild-collected ecotypes differed in Hsp101 expression responses across a 22 to 40 degrees C gradient. Genotypes from low latitudes expressed the least Hsp101. We tested fitness and pleiotropic consequences of varying Hsp101 expression in 'control' vs. mild thermal stress treatments (15/25 degrees C D/N vs. 15/25 degrees D/N plus 3 h at 35 degrees C 3 days/week). Comparing wild type and null mutants, wt Columbia (Col) produced approximately 33% more fruits compared to its Hsp101 homozygous null mutant. There was no difference between Landsberg erecta null mutant NIL (Ler) and wt Ler; wt Ler showed very low Hsp101 expression. In an assay of six genotypes, fecundity was a saturating function of Hsp101 content, in both experimental treatments. Thus, in addition to its essential role in acquired thermal tolerance, Hsp101 provides a substantial fitness benefit under normal growth conditions. Knocking out Hsp101 decreased fruit production, days to germination and days to bolting, total dry mass, and number of inflorescences; it increased transpiration rate and allocation to root mass. Root : total mass ratio decayed exponentially with Hsp101 content. This study shows that Hsp101 expression is evolvable in natural populations. Our results further suggest that Hsp101 is primarily an emergency high-temperature tolerance mechanism, since expression levels are lower in low-latitude populations from warmer climates. Hsp101 expression appears to carry an important trade-off in reduced root growth. This trade-off may select for suppressed expression under chronically high temperatures.

Clinical correlation of radiological spinal stenosis after standardization for vertebral body size

AIM

To determine the relationship between the degree of radiographic lumbar spinal stenosis, adjusted with an internal control for vertebral body size, and disability from lumbar stenosis.

MATERIALS AND METHODS

one hundred and twenty-three consecutive patients with clinical and radiological confirmation of neural impingement secondary to lumbar stenosis were enrolled prospectively. Thecal sac anteroposterior (AP) diameter (TSD) and cross-sectional area (CSA), and vertebral body AP dimension (VBD) were determined. These parameters were then correlated with patients' symptoms using the modified Roland-Morris questionnaire (RMQ) disability score.

RESULTS

No statistically significant inverse correlation was found between the TSD and RMQ score (p=0.433), between the CSA and RMQ score (p=0.124), or between the TSD:VBD ratio and RMQ score (p=0.109). There was a significant positive correlation between the CSA:VBD ratio and RMQ score (p=.036), and therefore, there was no statistical support for an inverse relationship between the two. There was a significant difference in mean RMQ scores when the patients were divided into those with CSA greater than or equal to 70 mm(2) and those less than 70 mm(2), with T=-2.104 and p=0.038.

CONCLUSION

The degree of radiographic lumbar spinal stenosis, even with the use of an internal control of vertebral body size and standardized disability questionnaires, does not correlate with clinical symptoms. However, patients with more severe stenosis below a CSA critical threshold of 70 mm(2), have significantly greater functional disability.

Detection of cathepsin S cysteine protease in human brain tumour microdialysates in vivo

Microdialysis enables the chemistry of extracellular fluid in body tissues to be measured. Extracellular proteases such as the cysteine protease, cathepsin S (CatS), are thought to facilitate astrocytoma invasion. Microdialysates obtained from human brain tumours in vivo were subjected to cathepsin S activity and ELISA assays. Cathepsin S ELISA expression was detected in five out of 10 tumour microdialysates, while activity was detected in five out of 11 tumour microdialysates. Cathepsin S expression was also detected in microdialysate from the normal brain control although no activity was found in the same sample. While some refinements to the technique are necessary, the authors demonstrate the feasibility and safety of microdialysis in human astrocytomas in vivo. Characterisation of the extracellular environment of brain tumours in vivo using microdialysis may be a useful tool to identify the protease profile of brain tumours.

Renal complications in HIV

Highly Active Antiretroviral Therapy has revolutionised the care of individuals living with HIV-1. As the prognosis for this population has improved, there is an increased risk of other major causes of morbidity and mortality, including renal disease. This review discusses the frequency and causes of renal pathology, how to make the diagnosis and monitor for renal disease in HIV-infected individuals. The review was conducted having examined the key evidence focussing upon HIV and renal complications obtained from peer-reviewed journals (level of evidence I-IV). As the population of individuals living with HIV increases, so too does the prevalence of renal disease. Physicians should be vigilant and recognise individuals at risk of renal complications, and be aware of how to monitor, investigate and treat those affected.

MLPA: a rapid, reliable, and sensitive method for detection and analysis of abnormalities of 22q

In this study, essential test characteristics of the recently described multiplex ligation-dependent probe amplification (MLPA) method are presented, using chromosome 22 as a model. This novel method allows the relative quantification of approximately 40-45 different target DNA sequences in a single reaction. For the purpose of this study, MLPA was performed in a blinded manner on a training set containing over 50 samples, including typical 22q11.2 deletions, various atypical deletions, duplications (trisomy and tetrasomy), and unbalanced translocations. All samples in the training set have been previously characterized by fluorescence in situ hybridization (FISH) with cosmid or BAC clones and/or cytogenetic studies. MLPA findings were consistent with cytogenetic and FISH studies, no rearrangement went undetected and repeated tests gave consistent results. At a relative change in comparative signal strength of 30% or more, sensitivity and specificity values were 0.95 and 0.99, respectively. Given that MLPA is likely to be used as an initial screening method, a higher sensitivity, at the cost of a lower specificity, was deemed more appropriate. A receiver operator characteristic (ROC) curve analysis was performed to calculate the most optimal threshold range, with associated sensitivity and specificity values of 0.99 and 0.97, respectively. Finally, performance of each individual probe was analyzed, providing further useful information for the interpretation of MLPA results. In conclusion, MLPA has proven to be a highly sensitive and accurate tool for detecting copy number changes in the 22q11.2 region, making it a fast and economic alternative to currently used methods. The current study provides valuable and detailed information on the characteristics of this novel method.