Bone marrow derivation of pericryptal myofibroblasts in the mouse and human small intestine and colon

BACKGROUND AND AIMS: In order to establish whether extraintestinal cells contribute to the turnover and repair of gastrointestinal tissues, we studied the colons and small intestines of female mice that had received a male bone marrow transplant, together with gastrointestinal biopsies from female patients that had developed graft versus host disease after receiving a bone marrow transplant from male donors. METHODS: Using in situ hybridisation to detect Y chromosomes and immunohistochemistry, we demonstrated that cells derived from injected bone marrow frequently engrafted into the intestine and differentiated into pericryptal myofibroblasts. RESULTS: In the human intestine, we confirmed by combining in situ hybridisation with immunostaining for smooth muscle actin that the bone marrow derived cells within the intestine exhibited a myofibroblast phenotype. In female mouse recipients of male bone marrow grafts, we observed colocalisation of Y chromosomes and clusters of newly formed marrow derived myofibroblasts. While few of these were present at seven days after bone marrow transplantation, they were numerous at 14 days, and by six weeks entire columns of pericryptal myofibroblasts could be seen running up the sides of crypts in both the small intestine and colon. These columns appeared to extend into the villi in the small intestine. Within the intestinal lamina propria, these Y chromosome positive cells were negative for the mouse macrophage marker F4/80 antigen and CD34. CONCLUSIONS: Bone marrow derived pericryptal myofibroblasts were present in the mouse intestine following irradiation and bone marrow transplant, and in the intestines of human patients suffering graft versus host disease following a bone marrow transplant. Our data indicate that bone marrow cells contribute to the regeneration of intestinal myofibroblasts and epithelium after damage, and we suggest that this could be exploited therapeutically.     

Inpatient resource utilization,disease severity,mortality and insurance coverage for patients hospitalized for hepatitis C virus in the United States

Although the incidence of new hepatitis C virus (HCV) infection has fallen, HCV‐related complications are on the rise. Our aim was to assess and describe the 2005–2009 national inpatient mortality and resource utilization trends for patients with HCV. Data from the National Inpatient Sample (NIS) and the National Hospital Discharge Survey (NHDS) between 2005 and 2009 were analyzed. Included were all adult hospital discharges with HCV‐related ICD‐9 codes. Incremental hospital charge, in‐hospital mortality and length of stay (LOS) were estimated using n = 1000 bootstrap replicates clustered by unique hospital identifier. A total of 123 939 (0.38%) discharges were related to HCV (primary or secondary diagnosis). In‐hospital mortality increased from 1.7% (2005) to 2.6% (2009) (P < 0.001). Inflation‐adjusted charges increased 2% annually from 2005 ($16 455 ±  $570) to 2009 ($17 532 ±  $1007, P = 0.029). This increase occurred despite the average LOS (5 days) and hospital costs ($6500) remaining stable while at the same time, hospital‐to‐hospital transfer admissions and disposition to home health care increased. HCV‐related hepatocellular carcinoma predicted longer hospital stay and death; older age predicted death; and receiving more procedures predicted higher hospital costs. The percentage of patients with private insurance significantly decreased (4.7%), while government‐sponsored insurance and uninsured increased by 2.5% and 2.1%, respectively (P < 0.05). Uninsured patients had a 49%–72% greater chance of dying during hospitalization than those with government‐sponsored insurance. HCV‐related inpatient mortality and resource utilization have increased. HCC was the largest predictor for mortality and resource utilization. These data are consistent with the rising clinical and societal burden of chronic hepatitis C in the United States.     

Transcatheter neoaortic valve replacement utilizing the melody valve in hypoplastic left heart syndrome

Percutaneous transcatheter pulmonary valve replacement with the Melody Valve is fast becoming an important adjunct in the treatment of older children and adults with failing right ventricular outflow tract conduits. Recently, the Melody Valve has also been successfully implanted in the tricuspid, mitral, and aortic positions, typically within a failing bioprosthetic valve. We present a patient who underwent Fontan palliation for hypoplastic left heart syndrome variant and subsequently developed severe neoaortic regurgitation, which was successfully treated with a transcatheter neoaortic valve replacement. To our knowledge, this is the first successful use of the Melody Valve in the neoaortic position in a patient with single‐ventricle physiology. Successful relief of neoaortic valve regurgitation using replacement with a transcatheter valve may allow avoidance of additional surgery, increase functional longevity of single‐ventricle palliation, and postpone the need for orthotopic heart transplantation. © 2014 Wiley Periodicals, Inc.     

A comparison of liquid and solid culture for determining relapse and durable cure in phase III TB trials for new regimens

Background

Tuberculosis kills more people than any other infectious disease, and new regimens are essential. The primary endpoint for confirmatory phase III trials for new regimens is a composite outcome that includes bacteriological treatment failure and relapse. Culture methodology is critical to the primary trial outcome. Patients in clinical trials can have positive cultures after treatment ends that may not necessarily indicate relapse, which was ascribed previously to laboratory cross-contamination or breakdown of old lesions. Löwenstein-Jensen (LJ) medium was the previous standard in clinical trials, but almost all current and future trials will use the Mycobacteria Growth Indicator Tube (MGIT) system due to its simplicity and consistency of use, which will affect phase III trial results.LJ was used for the definition of the primary endpoint in the REMoxTB trial, but every culture was also inoculated in parallel into the MGIT system. The data from this trial, therefore, provide a unique opportunity to investigate and compare the incidence of false ‘isolated positives’ in liquid and solid media and their potential impact on the primary efficacy results.

Methods

All post-treatment positive cultures were reviewed in the REMoxTB clinical trial. Logistic regression models were used to model the incidence of isolated positive cultures on MGIT and LJ.

Results

A total of 12,209 sputum samples were available from 1652 patients; cultures were more often positive on MGIT than LJ. In 1322 patients with a favourable trial outcome, 126 (9.5%) had cultures that were positive in MGIT compared to 34 (2.6%) patients with positive cultures on LJ. Among patients with a favourable outcome, the incidence of isolated positives on MGIT differed by study laboratory (p?<?0.0001) with 21.9% of these coming from one laboratory investigating only 4.9% of patients. No other baseline factors predicted isolated positives on MGIT after adjusting for laboratory. There was evidence of clustering of isolated positive cultures in some patients even after adjusting for laboratory, p?<?0.0001. The incidence of isolated positives on MGIT did not differ by treatment arm (p?=?0.845, unadjusted). Compared to negative MGIT cultures, positive MGIT cultures were more likely to be associated with higher grade TB symptoms reported within 7 days either side of sputum collection in patients with an unfavourable primary outcome (p?<?0.0001) but not in patients with a favourable outcome (p?=?0.481).

Conclusions

Laboratory cross-contamination was a likely cause of isolated positive MGIT cultures which were clustered in some laboratories. Certain patients had repeated positive MGIT cultures that did not meet the definition of a relapse. This pattern was too common to be explained by cross-contamination only, suggesting that host factors were also responsible. We conclude that MGIT can replace LJ in phase III TB trials, but there are implications for the definition of the primary outcome and patient management in trials in such settings. Most importantly, the methodologies differ in the incidence of isolated positives and in their capacity for capturing non-tuberculosis mycobacteria. It emphasises the importance of effective medical monitoring after treatment ends and consideration of clinical signs and symptoms for determining treatment failure and relapse.