Microbiota that affect risk for shigellosis in children in low-income countries.

Pathogens in the gastrointestinal tract exist within a vast population of microbes. We examined associations between pathogens and composition of gut microbiota as they relate to Shigella spp./enteroinvasive Escherichia coli infection. We analyzed 3,035 stool specimens (1,735 nondiarrheal and 1,300 moderate-to-severe diarrheal) from the Global Enteric Multicenter Study for 9 enteropathogens. Diarrheal specimens had a higher number of enteropathogens (diarrheal mean 1.4, nondiarrheal mean 0.95; p<0.0001). Rotavirus showed a negative association with Shigella spp. in cases of diarrhea (odds ratio 0.31, 95% CI 0.17-0.55) and had a large combined effect on moderate-to-severe diarrhea (odds ratio 29, 95% CI 3.8-220). In 4 Lactobacillus taxa identified by 16S rRNA gene sequencing, the association between pathogen and disease was decreased, which is consistent with the possibility that Lactobacillus spp. are protective against Shigella spp.-induced diarrhea. Bacterial diversity of gut microbiota was associated with diarrhea status, not high levels of the Shigella spp. ipaH gene.

The PPARα agonist fenofibrate suppresses B-cell lymphoma in mice by modulating lipid metabolism.

Obesity is associated with an increased risk for malignant lymphoma development. We used Bcr/Abl transformed B cells to determine the impact of aggressive lymphoma formation on systemic lipid mobilization and turnover. In wild-type mice, tumor size significantly correlated with depletion of white adipose tissues (WAT), resulting in increased serum free fatty acid (FFA) concentrations which promote B-cell proliferation in vitro. Moreover, B-cell tumor development induced hepatic lipid accumulation due to enhanced hepatic fatty acid (FA) uptake and impaired FA oxidation. Serum triglyceride, FFA, phospholipid and cholesterol levels were significantly elevated. Consistently, serum VLDL/LDL-cholesterol and apolipoprotein B levels were drastically increased. These findings suggest that B-cell tumors trigger systemic lipid mobilization from WAT to the liver and increase VLDL/LDL release from the liver to promote tumor growth. Further support for this concept stems from experiments where we used the peroxisome proliferator-activated receptor α (PPARα) agonist and lipid-lowering drug fenofibrate that significantly suppressed tumor growth independent of angiogenesis and inflammation. In addition to WAT depletion, fenofibrate further stimulated FFA uptake by the liver and restored hepatic FA oxidation capacity, thereby accelerating the clearance of lipids released from WAT. Furthermore, fenofibrate blocked hepatic lipid release induced by the tumors. In contrast, lipid utilization in the tumor tissue itself was not increased by fenofibrate which correlates with extremely low expression levels of PPARα in B-cells. Our data show that fenofibrate associated effects on hepatic lipid metabolism and deprivation of serum lipids are capable to suppress B-cell lymphoma growth which may direct novel treatment strategies. This article is part of a Special Issue entitled Lipid Metabolism in Cancer.

Biliary atresia with splenic malformation with associated ductal plate malformation and duodenal atresia: A case report.

ABSTRACT: Biliary atresia (BA) is the most common cause of the obstructive type of neonatal cholestasis that requires prompt surgical intervention. About 10% of neonates with BA have other congenital anomalies, of which splenic malformation (BASM) is a well-known distinct sub-group. There is sparse literature on the association of duodenal atresia and ductal plate malformation (DPM) in patients of BASM. We describe a BASM associated with DPM and duodenal atresia in a 35-day-old infant, who succumbed at 40 days, before portoenterostomy could be performed. Duodenal atresia can be one of the associated malformations associated with BASM and ductal plate abnormalities. In our case, the child did not survive.

Cancer cachexia alters intracellular surfactant metabolism but not total alveolar surface area.

Dyspnoea is frequently observed in cancer cachectic patients. Little is known whether this is accompanied by structural or functional alterations of the lung. We hypothesized that in analogy to calorie restriction cancer cachexia leads to loss of alveolar surface area and surfactant. Mice were subjected to subcutaneous injection of Lewis lung carcinoma cells (tumour group, TG) or saline (control group, CG). Twenty-one days later blood samples and the lungs were taken. Using design-based stereology, the alveolar surface area and the lamellar body (Lb) content were quantified. Messenger RNA expression of surfactant proteins, ABCA3 and various growth factors was investigated by quantitative RT-PCR. Intraalveolar surfactant subtype composition was analyzed by differential centrifugation. TG mice showed reduced body weight and anaemia but no reduction of lung volume or alveolar surface area. The volume of Lb was significantly reduced and mRNA levels of ABCA3 transporter tended to be lower in TG versus CG. Surfactant protein expression and the ratio between active and inactive intraalveolar surfactant subtypes were not altered in TG. Growth factor mRNA levels were not different between CG and TG lungs but the tumour expressed growth factor mRNA. Vascular endothelial growth factor was significantly enhanced in blood plasma. The present study demonstrates structural alterations of the lung associated with cancer cachexia. These include reduction of Lb content despite normal intraalveolar surfactant and alveolar surface area. The pulmonary phenotype of the cancer cachectic mouse differs from the calorie restricted mouse possibly due to growth factors released from the tumour tissue.

Apoptosis and fibrosis are early features of heart failure in an animal model of metabolic cardiomyopathy.

In previous experiments, we observed signs of cardiac failure in mice overexpressing lipoprotein lipase (LPL) under the control of a muscle specific promotor and in peroxisome proliferators activated receptor alpha (PPARalpha) knockout mice overexpressing LPL under the control of the same promotor. In our current investigations, we focussed on morphological consequences and changes in mRNA and protein expression in hearts from these animals. mRNA expression was analysed by differential display analysis and Northern blot as well as by cDNA microarray analysis followed by pathway analysis. Protein expression was examined using immunoblot and immunohistochemistry. Fibrosis was determined by chromotrope aniline blue staining for collagen. A distinct increase in the expression of alpha-tubulin mRNA was noted in hearts of all mutant mouse strains compared with the control. This result was paralleled by increased alpha-tubulin protein expression. Using cDNA microarray analysis, we detected an activation of apoptosis, in particular an increase of caspase-3 expression in hearts of mice overexpressing LPL but not in PPARalpha knockout mice overexpressing LPL. This finding was confirmed immunohistochemically. In addition, we identified a distinct interstitial increase in collagen and an increase around blood vessels. In our mouse model, we detect mRNA and protein changes typical for cardiomyopathy even before overt clinical signs of heart failure. In addition, a small but distinct increase in the rate of apoptosis of cardiomyocytes and fibrotic changes contributes to cardiac failure in mice overexpressing LPL, whereas additional deficiency in PPARalpha seems to protect hearts from these effects.

Effects of Lewis lung carcinoma and B16 melanoma on the innervation of the mouse trachea.

Cancer patients often suffer from dyspnea the pathogenesis of which is incompletely understood. Both dyspnea and pulmonary diseases are closely linked to airway innervation. Recently, it was shown that Lewis lung carcinoma induces cardiac hypoinnervation in the mouse. We hypothesized that airway innervation undergoes similar changes as myocardial innervation and that this effect occurs in different mouse models of cancer. C57Bl6 mice were randomly assigned to subcutaneous injection of Lewis lung carcinoma cells (LLC, n=6), B16 melanoma cells (B16, n=6), or saline (control group, C, n=10). After 16 or 21 days, respectively, the trachea was processed for light and electron microscopic design-based stereology and the volume, surface area and length of axons ramifying in the tracheal wall were estimated. Body weight was reduced both in LLC and B16 vs. C. Hypoinnervation was present in both tumor groups compared to controls as volume and surface area of axons were significantly reduced in LLC and B16. However, the total length of tracheal axons and the mean number of axons per nerve fiber were reduced only in LLC but not in B16 compared to C indicating a differentially pronounced effect of cancer on tracheal innervation. In conclusion, reduced innervation of the trachea was observed in two different murine tumor models. These findings add to the pathophysiological concepts explaining cancer-related dyspnea and open new perspectives of treating this symptom.

Cancer induces cardiomyocyte remodeling and hypoinnervation in the left ventricle of the mouse heart.

Cancer is often associated with cachexia, cardiovascular symptoms and autonomic dysregulation. We tested whether extracardiac cancer directly affects the innervation of left ventricular myocardium. Mice injected with Lewis lung carcinoma cells (tumor group, TG) or PBS (control group, CG) were analyzed after 21 days. Cardiac function (echocardiography), serum levels of TNF-α and Il-6 (ELISA), structural alterations of cardiomyocytes and their innervation (design-based stereology) and levels of innervation-related mRNA (quantitative RT-PCR) were analysed. The groups did not differ in various functional parameters. Serum levels of TNF-α and Il-6 were elevated in TG. The total length of axons in the left ventricle was reduced. The number of dense core vesicles per axon profile was reduced. Decreased myofibrillar volume, increased sarcoplasmic volume and increased volume of lipid droplets were indicative of metabolic alterations of TG cardiomyocytes. In the heart, the mRNA level of nerve growth factor was reduced whereas that of ß1-adrenergic receptor was unchanged in TG. In the stellate ganglion of TG, mRNA levels of nerve growth factor and neuropeptide Y were decreased and that of tyrosine hydroxylase was increased. In summary, cancer induces a systemic pro-inflammatory state, a significant reduction in myocardial innervation and a catabolic phenotype of cardiomyocytes in the mouse. Reduced expression of nerve growth factor may account for the reduced myocardial innervation.