Pigs and humans with cystic fibrosis have reduced insulin-like growth factor 1 (IGF1) levels at birth

People with cystic fibrosis (CF) exhibit growth defects. That observation has been attributed, in part, to decreased insulin-like growth factor 1 (IGF1) levels, and the reduction has been blamed on malnutrition and pulmonary inflammation. However, patients with CF already have a reduced weight at birth, a manifestation not likely secondary to poor nutrition or inflammation. We found that, like humans, CF pigs were smaller than non-CF littermates and had lower IGF1 levels. To better understand the basis of IGF1 reduction, we studied newborn pigs and found low IGF1 levels within 12 h of birth. Moreover, humerus length and bone mineral content were decreased, consistent with less IGF1 activity in utero. These findings led us to test newborn humans with CF, and we found that they also had reduced IGF1 levels. Discovering lower IGF1 levels in newborn pigs and humans indicates that the decrease is not solely a consequence of malnutrition or pulmonary inflammation and that loss of cystic fibrosis transmembrane conductance regulator function has a more direct effect. Consistent with this hypothesis, we discovered reduced growth hormone release in organotypic pituitary slice cultures of newborn CF pigs. These findings may explain the long-standing observation that CF newborns are smaller than non-CF babies and why some patients with good clinical status fail to reach their growth potential. The results also suggest that measuring IGF1 levels might be of value as a biomarker to predict disease severity or the response to therapeutics. Finally, they raise the possibility that IGF1 supplementation beginning in infancy might be beneficial in CF.     

Production of CFTR-null and CFTR-DeltaF508 heterozygous pigs by adeno-associated virus-mediated gene targeting and somatic cell nuclear transfer

Progress toward understanding the pathogenesis of cystic fibrosis (CF) and developing effective therapies has been hampered by lack of a relevant animal model. CF mice fail to develop the lung and pancreatic disease that cause most of the morbidity and mortality in patients with CF. Pigs may be better animals than mice in which to model human genetic diseases because their anatomy, biochemistry, physiology, size, and genetics are more similar to those of humans. However, to date, gene-targeted mammalian models of human genetic disease have not been reported for any species other than mice. Here we describe the first steps toward the generation of a pig model of CF. We used recombinant adeno-associated virus (rAAV) vectors to deliver genetic constructs targeting the CF transmembrane conductance receptor (CFTR) gene to pig fetal fibroblasts. We generated cells with the CFTR gene either disrupted or containing the most common CF-associated mutation (DeltaF508). These cells were used as nuclear donors for somatic cell nuclear transfer to porcine oocytes. We thereby generated heterozygote male piglets with each mutation. These pigs should be of value in producing new models of CF. In addition, because gene-modified mice often fail to replicate human diseases, this approach could be used to generate models of other human genetic diseases in species other than mice.     

Functional Dyspepsia Treatment Trial (FDTT): a double-blind, randomized, placebo-controlled trial of antidepressants in functional dyspepsia, evaluating symptoms, psychopathology, pathophysiology and pharmacogenetics

BACKGROUND: Functional dyspepsia (FD) is a common problem affecting up to 10-25% of individuals. FD accounts for significant health care costs and affects quality of life but has no definitive treatment. OBJECTIVES: The Functional Dyspepsia Treatment Trial (FDTT) aims to test whether treatment with an antidepressant (amitriptyline or escitalopram) leads to improvement of symptoms in patients with moderate to severe FD. DESIGN: The FDTT is an international multicenter, parallel group, randomized, double-blind, placebo-controlled trial to evaluate whether 12 weeks of treatment with escitalopram or amitriptyline improves FD symptoms compared to treatment with placebo. Secondly, it is hypothesized that acceleration of solid gastric emptying, reduction of postprandial satiation, and enhanced gastric volume change with a meal will be significant positive predictors of short- and long-term outcomes for those on antidepressants vs. placebo. The third aim is to examine whether polymorphisms of GNβ3 and serotonin reuptake transporter influence treatment outcomes in FD patients receiving a tricyclic antidepressant, selective serotonin reuptake inhibitor therapy, or placebo. METHODS: The FDTT enrollment began in 2006 and is scheduled to randomize 400 patients by the end of 2012 to receive an antidepressant or placebo for 12 weeks, with a 6-month post-treatment follow-up. The study incorporates multiple validated questionnaires, physiological testing, and specific genetic evaluations. The protocol was approved by participating centers' Institutional Review Boards and an independent Data Safety Monitoring Board was established for monitoring to ensure patient safety and a single interim review of the data in December 2010 (ClinicalTrials.gov number NCT00248651).     

Clinical evaluation of serum fructosamine in monitoring elderly outpatient diabetics

Recently, new serum glycated protein assays (ie, serum fructosamine) have been developed. Fructosamine assays objectively monitor short-term glycemic control and, when used in conjunction with HgA1C, enhance the clinical information obtained and greatly aid in the clinical management of diabetes. Because they rely on glycation of serum proteins, the clinical utility of these assays in the elderly may be altered secondary to the hypoproteinemia that often is seen in these states. Therefore, we investigated the role of glycated serum proteins (ie, fructosamine level) in monitoring elderly diabetics over a 4-month period of observation. We found that the fasting blood glucose over the 4-month period correlated well with the serum fructosamine activity (r = 0.79, P less than .001) and HgA1C (r = 0.78, P less than .001). In addition, we found that the mean daily glucose, as determined by outpatient monitoring, correlated well to both the fructosamine activity (r = 0.66, P less than .001) and HgA1C (r = 0.74, P less than .001). We found no effect on the measurement of the fructosamine assay by the level of albumin seen in these patients. Our study suggests that serum fructosamine and HgA1C are equally effective in monitoring the elderly patient, as has been established in the younger diabetic, and no correction need be made in the fructosamine assay to compensate for variable serum protein levels seen clinically in the elderly.     

Palmitoylethanolamide Regulates Development of Intestinal Radiation Injury in a Mast Cell-Dependent Manner

Background

Mast cells and neuroimmune interactions regulate the severity of intestinal radiation mucositis, a dose-limiting toxicity during radiation therapy of abdominal malignancies.

Aim

Because endocannabinoids (eCB) regulate intestinal inflammation, we investigated the effect of the cannabimimetic, palmitoylethanolamide (PEA), in a mast competent (+/+) and mast cell-deficient (Ws/Ws) rat model.

Methods

Rats underwent localized, fractionated intestinal irradiation, and received daily injections with vehicle or PEA from 1 day before until 2 weeks after radiation. Intestinal injury was assessed noninvasively by luminol bioluminescence, and, at 2 weeks, by histology, morphometry, and immunohistochemical analysis, gene expression analysis, and pathway analysis.

Results

Compared with +/+ rats, Ws/Ws rats sustained more intestinal structural injury (p = 0.01), mucosal damage (p = 0.02), neutrophil infiltration (p = 0.0003), and collagen deposition (p = 0.004). PEA reduced structural radiation injury (p = 0.02), intestinal wall thickness (p = 0.03), collagen deposition (p = 0.03), and intestinal inflammation (p = 0.02) in Ws/Ws rats, but not in +/+ rats. PEA inhibited mast cell-derived cellular immune response and anti-inflammatory IL-6 and IL-10 signaling and activated the prothrombin pathway in +/+ rats. In contrast, while PEA suppressed nonmast cell-derived immune responses, it increased anti-inflammatory IL-10 and IL-6 signaling and decreased activation of the prothrombin pathway in Ws/Ws rats.

Conclusions

These data demonstrate that the absence of mast cells exacerbate radiation enteropathy by mechanisms that likely involve the coagulation system, anti-inflammatory cytokine signaling, and the innate immune system; and that these mechanisms are regulated by PEA in a mast cell-dependent manner. The eCB system should be explored as target for mitigating intestinal radiation injury.     

Subtypes of constipation: sorting out the confusion

In patients with chronic constipation, identifying subtypes based on underlying physiology guides subsequent therapeutic choices. Chronic constipation subtypes include slow-transit constipation, pelvic floor dyssynergia, functional constipation, and irritable bowel syndrome with constipation. Chronic constipation subtypes are defined by the result of colonic transit, pelvic floor function, and the presence or absence of significant abdominal pain. Although a variety of tests are available, the most straightforward approach uses the 5-day colonic marker test of transit and anorectal manometry with balloon expulsion testing to evaluate for pelvic floor dysfunction. Patients with normal physiologic tests have either irritable bowel syndrome with constipation or normal-transit constipation. Significant overlap exists between subtypes and a clear distinction is not always possible, with up to a 50% overlap between patients with slow-transit constipation and irritable bowel syndrome, approximately 10% of patients evaluated exhibiting both slow transit and pelvic floor dyssynergia, and 50% of patients with pelvic floor dyssynergia also found to have slow transit. Symptom severity assessment provides the rationale for pursuing further testing and directing the aggressiveness of treatment as patients with greater symptom severity have reduced quality of life and poor physical functioning scores. Few constipation-specific validated measures exist for measuring symptom severity in chronic constipation. In clinical practice severity may be defined as mild symptoms having minimal impact upon daily activities or moderate to severe symptoms that increasingly interfere with daily life.     

Tegaserod accelerates orocecal transit in patients with constipation-predominant irritable bowel syndrome

BACKGROUND & AIMS: This study evaluated the effects of a partial 5-hydroxytryptamine (5-HT)(4) agonist, tegaserod, on gastric small bowel and colonic transit in constipation-predominant irritable bowel syndrome (IBS). METHODS: After a 1 week run-in period, 24 patients with constipation-predominant IBS were randomized to 1 week of tegaserod, 2 mg twice daily, or placebo treatment. Scintigraphic gastric emptying, small bowel transit, and colonic transit were determined before administration of study drug and after 1 week on the medication. Colonic transit was also measured using radiopaque markers and a single radiograph on day 5. RESULTS: Gastric emptying was unaltered by tegaserod. Proximal colonic filling at 6 hours, a measure of orocecal transit, was accelerated by tegaserod (70.4% +/- 1.3% [mean +/- SEM] vs. placebo, 46.4 +/- 1.9; P = 0.015). Proximal colonic emptying half-time and geometric center at 48 hours were also accelerated by tegaserod compared with baseline, but not compared with placebo. Mean colonic transit time was similar in both groups at baseline and after drug administration (tegaserod, 59.5 +/- 2.1 hours; placebo, 62.1 +/- 2.1 hours). CONCLUSIONS: Tegaserod accelerates orocecal transit, tends to accelerate colonic transit, and deserves further study in patients with constipation-predominant IBS.