Tropheryma whipplei, a Potential Commensal Detected in Individuals Undergoing Routine Colonoscopy.

Mucosal biopsy samples from individuals not suspected of having Whipple's disease were tested for the presence of Tropheryma whipplei. A sensitive and specific real-time PCR assay targeting a sequence present seven times in the T. whipplei genome was used. T. whipplei DNA was detected in 2.0 and 3.8% of the patients undergoing gastroduodenoscopy and colonoscopy, respectively, who were tested.

Peritoneal dialysis-associated peritonitis of zoonotic origin, when minor gets major.

A 62-year-old patient with peritoneal dialysis (PD)-associated peritonitis is described. Identical strains of Pasteurella multocida and Streptococcus minor were cultured from the dialysate, and from the saliva of her recently adopted stray cat. Pasteurella is not often encountered as pathogen in PD-associated peritonitis, Streptococcus minor has never been cultured in human infection before. We emphasise the importance of hygiene in peritoneal dialysis and the need for testing pets when zoonotic pathogens are cultured.

LXR is a negative regulator of glucose uptake in human adipocytes.

AIMS/HYPOTHESIS: Obesity increases the risk of developing type 2 diabetes mellitus, characterised by impaired insulin-mediated glucose uptake in peripheral tissues. Liver X receptor (LXR) is a positive regulator of adipocyte glucose transport in murine models and a possible target for diabetes treatment. However, the levels of LXRα are increased in obese adipose tissue in humans. We aimed to investigate the transcriptome of LXR and the role of LXR in the regulation of glucose uptake in primary human adipocytes. METHODS: The insulin responsiveness of human adipocytes differentiated in vitro was characterised, adipocytes were treated with the LXR agonist GW3965 and global transcriptome profiling was determined by microarray, followed by quantitative RT-PCR (qRT-PCR), western blot and ELISA. Basal and insulin-stimulated glucose uptake was measured and the effect on plasma membrane translocation of glucose transporter 4 (GLUT4) was assayed. RESULTS: LXR activation resulted in transcriptional suppression of several insulin signalling genes, such as AKT2, SORBS1 and CAV1, but caused only minor changes (<15%) in microRNA expression. Activation of LXR impaired the plasma membrane translocation of GLUT4, but not the expression of its gene, SLC2A4. LXR activation also diminished insulin-stimulated glucose transport and lipogenesis in adipocytes obtained from overweight individuals. Furthermore, AKT2 expression was reduced in obese adipose tissue, and AKT2 and SORBS1 expression was inversely correlated with BMI and HOMA index. CONCLUSIONS/INTERPRETATION: In contrast to murine models, LXR downregulates insulin-stimulated glucose uptake in human adipocytes from overweight individuals. This could be due to suppression of Akt2, c-Cbl-associated protein and caveolin-1. These findings challenge the idea of LXR as a drug target in the treatment of diabetes.

[Submucosal presentation of Whipple's disease: a variant that is easily missed]. / Submucosale presentatie van de ziekte van Whipple: een variant die gemakkelijk wordt gemist.

Whipple's disease is a multisystem, and often chronic, disease caused by infection with the bacterium Tropheryma whipplei, and mainly occurs in middle-aged Caucasian men. In most cases, histological detection of large numbers of bacteria-laden macrophages in the mucosa of the small intestine confirms the diagnosis. Less commonly, these macrophages may be sparse and predominantly located beneath the mucosa. In these submucosally presenting cases, endoscopic and classic histological clues are absent and, therefore, the diagnosis can be missed. As a result, further periodic acid-Schiff (PAS) staining and PCR analysis are of great importance in arriving at the correct diagnosis.

Gastroenteritis caused by Campylobacter concisus.

We describe a case of gastroenteritis caused by Campylobacter concisus. The pathogenic potential of C. concisus has yet to be elucidated. Recent studies indicate an association with enteric disease in immunocompromised patients and inflammatory bowel disease in children. Molecular identification methods may be necessary for identifying certain Campylobacter species because of phenotypic similarity.