Functional bowel symptoms in quiescent inflammatory bowel diseases: role of epithelial barrier disruption and low-grade inflammation

OBJECTIVE

To determine the role of colonic barrier defects and low-grade inflammation in irritable bowel syndrome (IBS)-like symptoms in quiescent inflammatory bowel disease (IBD).

DESIGN

Caecal biopsies were collected from 51 IBS, 49 quiescent IBD (31 Crohn's disease (CD) and 18 ulcerative colitis (UC)) patients and 27 controls. IBS was assessed using the Rome III criteria and the IBS severity score. Epithelial barrier integrity was evaluated by determining the paracellular permeability of biopsies mounted in Ussing chambers and the mRNA expression of tight junction proteins (ZO-1, α-catenin and occludin). Low-grade inflammation was evaluated by counting cells, including intraepithelial lymphocytes (IELs), eosinophils and mast cells, and by determining the mRNA and protein expression of tumour necrosis factor (TNF)-α in biopsies and culture supernatants.

RESULTS

IBS-like symptoms were present in 35.4 and 38% of CD and UC patients, respectively. Paracellular permeability was significantly increased in both quiescent IBD with IBS-like symptoms and IBS compared with quiescent IBD without IBS-like symptoms (p<0.01, respectively) or controls (p<0.01, respectively). Significantly lower expression of ZO-1 and α-catenin was detected in IBS and quiescent IBD with IBS-like symptoms. IELs and TNF-α were significantly increased in quiescent IBD with IBS-like symptoms, but not in IBS.

CONCLUSIONS

In quiescent IBD, IBS-like symptoms related to persistent subclinical inflammation associated with increased colonic paracellular permeability. A persistent increase in TNF-α in colonic mucosa may contribute to the epithelial barrier defects associated with abdominal pain in quiescent IBD, but not in IBS. Optimisation of anti-inflammatory therapy may be considered in quiescent IBD with IBS-like symptoms.

Models of interinstitutional partnerships between research intensive universities and minority serving institutions (MSI) across the Clinical Translational Science Award (CTSA) consortium

Health disparities are an immense challenge to American society. Clinical and Translational Science Awards (CTSAs) housed within the National Center for Advancing Translational Science (NCATS) are designed to accelerate the translation of experimental findings into clinically meaningful practices and bring new therapies to the doorsteps of all patients. Research Centers at Minority Institutions (RCMI) program at the National Institute on Minority Health and Health Disparities (NIMHD) are designed to build capacity for biomedical research and training at minority serving institutions. The CTSA created a mechanism fostering formal collaborations between research intensive universities and minority serving institutions (MSI) supported by the RCMI program. These consortium-level collaborations activate unique translational research approaches to reduce health disparities with credence to each academic institutions history and unique characteristics. Five formal partnerships between research intensive universities and MSI have formed as a result of the CTSA and RCMI programs. These partnerships present a multifocal approach; shifting cultural change and consciousness toward addressing health disparities, and training the next generation of minority scientists. This collaborative model is based on the respective strengths and contributions of the partnering institutions, allowing bidirectional interchange and leveraging NIH and institutional investments providing measurable benchmarks toward the elimination of health disparities.

Preparedness of the CTSA's structural and scientific assets to support the mission of the National Center for Advancing Translational Sciences (NCATS)

The formation of the National Center for Advancing Translational Sciences (NCATS) brings new promise for moving basic science discoveries to clinical practice, ultimately improving the health of the nation. The Clinical and Translational Science Award (CTSA) sites, now housed with NCATS, are organized and prepared to support in this endeavor. The CTSAs provide a foundation for capitalizing on such promise through provision of a disease-agnostic infrastructure devoted to clinical and translational (C&T) science, maintenance of training programs designed for C&T investigators of the future, by incentivizing institutional reorganization and by cultivating institutional support.

Scientific and logistical challenges in designing the CONTROL trial: recombinant factor VIIa in severe trauma patients with refractory bleeding

BACKGROUND

Clinical research in trauma patients poses multiple challenges in study design. These reflect the heterogeneity of injury and treatment, the paucity of acceptable study endpoints aside from mortality, and the difficulties inherent in obtaining informed consent in acutely ill populations. A current example of this problem is the study of recombinant factor VIIa (rFVIIa), which has attracted considerable interest as a systemic procoagulant agent for use in trauma patients with exsanguinating hemorrhage.

PURPOSE

To report on the implementation of an international trial - CONTROL - intended to assess the efficacy and safety of rFVIIa in trauma, and discuss trauma research study design in light of this experience.

METHODS

The CONTROL trial international steering committee confronted a number of barriers in the design of the CONTROL trial. They addressed methodologies for (1) standardizing entry criteria for trauma patients suffering inherently heterogeneous injuries, (2) obtaining informed consent in an acutely injured population with altered levels of consciousness, (3) avoiding futile care, while recruiting subjects with incompletely diagnosed injuries, (4) standardizing trauma intensive care across different investigating sites and countries, and (5) establishing study endpoints that were both clinically relevant and convincing to regulatory authorities. The resulting study methodology is reported.

RESULTS

The CONTROL trial began active recruitment in October 2005, and was halted on June 11, 2008 because the observed mortality in the 576 enrolled patients was so far below expectations that the study would lack sufficient statistical power at the planned number of subjects to demonstrate a benefit. The utility of the endpoints selected for study will not be known until completion of data analysis.

LIMITATIONS

Any clinical trial in trauma patients must cope with the urgency of care required, issues of patient heterogeneity, standardization of care across multiple centers, and the difficulties of obtaining informed consent.

CONCLUSION

Research in acutely hemorrhaging trauma patients presents numerous scientific and ethical challenges. The methodology of the CONTROL study is presented as an example of how some of these challenges can be approached and managed, and of the pitfalls that may arise.

Frequency and severity of ileal adenomas in familial adenomatous polyposis after colectomy

BACKGROUND AND STUDY AIMS

The high cumulative risk of colorectal cancer in patients with familial adenomatous polyposis (FAP) justifies prophylactic colectomy with either ileorectal (IRA) or ileal-pouch-anal anastomosis (IPAA). Our aim was to evaluate retrospectively the frequency of and time interval to adenoma development in the ileal mucosa of patients with both types of surgery.

PATIENTS AND METHODS

Retrospective study of 44 FAP patients with IRA (n = 21) and IPAA (n = 23). All patients were followed with a standardized procedure including chromoscopy and biopsies of visible polyps. In patients with IRA, specific attention was paid to the ileal mucosa above the anastomosis.

RESULTS

In the IPAA group, 18/23 patients (78 %) presented with visible polyps [histology: 16 (70 %) had adenoma with low-grade dysplasia; 1 (4 %) had adenoma with high-grade dysplasia; 1 had normal mucosa]. The mean interval between colectomy and the diagnosis of adenoma was 4.7 +/- 3.3 years. In the IRA group, 16/21 patients (77 %) presented visible polyps in the ileal mucosa [adenoma with low-grade dysplasia in 8 patients (38 %), with high-grade dysplasia in 2 (10 %), and lymphoid nodular hyperplasia in 6]. The mean interval between colectomy and adenoma diagnosis was significantly shorter in the IPAA than in the IRA group (4.76 +/- 3.3 vs. 16.4 +/- 8.5 years, P< 0.0001).

CONCLUSION

Our results show a high frequency of adenomas in the ileal mucosa of patients with IPAA and IRA (74 % and 48 % respectively), with evolution into high-grade dysplasia in 6.7 % of cases.

CD99 isoforms dictate opposite functions in tumour malignancy and metastases by activating or repressing c-Src kinase activity

CD99 gene encodes two distinct proteins, produced by alternative splicing of CD99 gene transcript. Full-length CD99 isoform (CD99wt) is formed by an extracellular domain, followed by a transmembrane domain and a 36 amino-acid intracytoplasmic domain, which is partially deleted in the truncated, short form (CD99sh). A differential expression of these two CD99 molecules can lead to distinct functional outcomes in lymphocytes. To investigate the functional effects of CD99 molecules on malignancy, forced overexpression of the two CD99 isoforms was induced in osteosarcoma and prostate cancer cells. The two isoforms exhibited opposite functions: the major form dramatically inhibits anchorage-independent growth, anoikis resistance, migration and metastasis, whereas the CD99sh remarkably favours the phenomena. A mechanistic analysis of CD99-transfected osteosarcoma cells points to involvement of c-Src family kinase activity in regulating CD99 functions in malignancy. Ser168 residue of CD99 plays a pivotal role in the reversion of the malignant phenotype. Our findings highlight the involvement of CD99 in crucial processes of cancer malignancy, serving as a curtain raiser for this, so far neglected molecule. In addition, a dualistic role for the two CD99 isoforms was shown in agreement with what was observed for other cell adhesion molecules.

Spontaneous hypoglycaemia in the presence of both anti-insulin antibody and anti-insulin receptor antibody

Beside insulinoma, alternative causes of hyperinsulinaemic hypoglycaemia include the rare autoimmune syndrome related to spontaneous autoantibodies either to insulin or to insulin receptor. We describe a case of hypoglycaemia with high insulinemia in which insulinoma could not be evidenced. Surprisingly, we found in the patient's serum both insulin autoantibodies and insulin receptor autoantibodies. Available data eventually supported the predominant role of insulin autoantibodies rather than insulin receptor autoantibodies in the mechanism of hypoglycaemia of this patient. Insulin antibodies were present in high titre. Most of the insulin in serum was bound to the insulin antibodies and free insulin was slightly increased. HLA typing displayed DR4 haplotype, known to be strongly linked to the insulin autoimmune syndrome. The patient's serum was able to inhibit insulin binding to its receptor in a cultured cell line overexpressing insulin receptors both in experiments with native serum and with serum depleted from insulin antibodies. However, we could not demonstrate that the insulin receptor antibodies had insulin mimicking effect. We have no obvious explanation for the presence of these two antibodies in the same patient. Possible hypotheses might involve an idiotype-anti-idiotype mechanism or a poly-autoimmune disease.

Controversies in sepsis clinical trials: proceedings of a meeting of the International Sepsis Forum, Lausanne, Switzerland, September 29, 2001

Despite some recent success with clinical trials studying innovative therapies in sepsis, the field remains predominantly one of failure despite compounds with significant preclinical activity. Preclinical animal experimentation remains an important component of drug development, and a portfolio approach is recommended. Failure in animals is more likely to predict failure in humans; however, success in animals often does not predict success in humans. Because the signal with innovative therapy of sepsis is likely to be low, an oncology model clinical trial approach, in which studies start with a high-risk homogeneous population and look for a large treatment effect with smaller numbers of patients, is likely to be more relevant than the commonly used cardiology model, in which studies search for a small treatment effect using large, heterogeneous, low-risk populations. With certain rules in place, improvement in organ function may be a worthwhile alternative to mortality as a clinical end point. Once a therapy is approved, adopting less stringent but still appropriate criteria for the use of that therapy in clinical practice may be appropriate.