250 research outputs found

    Selective Uptake Into Inflamed Human Intestinal Tissue and Immune Cell Targeting by Wormlike Polymer Micelles

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    Inflammatory bowel disease (IBD) has become a globally prevalent chronic disease with no causal therapeutic options. Targeted drug delivery systems with selectivity for inflamed areas in the gastrointestinal tract promise to reduce severe drug-related side effects. By creating three distinct nanostructures (vesicles, spherical, and wormlike micelles) from the same amphiphilic block copolymer poly(butyl acrylate)-block-poly(ethylene oxide) (PBA-b-PEO), the effect of nanoparticle shape on human mucosal penetration is systematically identified. An Ussing chamber technique is established to perform the ex vivo experiments on human colonic biopsies, demonstrating that the shape of polymeric nanostructures represents a rarely addressed key to tissue selectivity required for efficient IBD treatment. Wormlike micelles specifically enter inflamed mucosa from patients with IBD, but no significant uptake is observed in healthy tissue. Spheres (≈25 nm) and vesicles (≈120 nm) enter either both normal and inflamed tissue types or do not penetrate any tissue. According to quantitative image analysis, the wormlike nanoparticles localize mainly within immune cells, facilitating specific targeting, which is crucial for further increasing the efficacy of IBD treatment. These findings therefore demonstrate the untapped potential of wormlike nanoparticles not only to selectively target the inflamed human mucosa, but also to target key pro-inflammatory cells.</p

    Inherited renal tubular dysgenesis: the first patients surviving the neonatal period

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    Renal tubular dysgenesis (RTD) is a clinical disorder either acquired during fetal development or inherited as an autosomal recessive condition. Inherited RTD is caused by mutations in the genes encoding the components of the renin-angiotensin system angiotensinogen, renin, angiotensin-converting enzyme and angiotensin II receptor type 1. Inherited RTD is characterized by early onset oligohydramnios, skull ossification defects, preterm birth and neonatal pulmonary and renal failure. The histological hallmark is the absence or poor development of proximal tubules. So far, all patients died either in utero or shortly after birth. We report the first patients with inherited RTD surviving the neonatal period and still being alive. Genetic and functional analysis of the renin-angiotensin system contributes to the diagnosis of RTD. In conclusion, the clinical diagnosis of inherited RTD is easily missed after birth without renal biopsy or information on affected family members. Genetic and functional analysis of the renin-angiotensin system contributes to correct diagnosis

    Faecal Matrix Metalloprotease-9 Is a More Sensitive Marker For Diagnosing Pouchitis Than Faecal Calprotectin – Results From a Pilot Study

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    Background. Potential non-invasive markers of pouchitis would have a great deal of significance within clinical practice. This study is aimed at assessing the diagnostic accuracy of faecal calprotectin and matrix metalloprotease-9 as potential markers in patients both with and without pouchitis. Patients and methods. Stool and blood samples were collected from 33 ileal pouch-anal anastomosis patients before a follow-up pouchoscopy. Biopsy samples were taken for histological purposes. The presence of cuffitis and stenosis was evaluated with an endoscopy. Calprotectin and matrix metalloprotease-9 were quantified with an enzyme-linked immunosorbent assay. Results. Pouchitis was detected in 30.3% of the patients. The levels of faecal calprotectin and matrix metalloprotease-9 increased significantly in patients with pouchitis. The sensitivity and specificity of matrix metalloprotease-9 was higher than that of faecal calprotectin. Only matrix metalloprotease-9 correlated significantly with the severity of pouchitis. Conclusions. Faecal matrix metalloprotease-9 has a high specificity in the diagnosis of pouchitis

    Elevated serum procollagen type III peptide in splanchnic and peripheral circulation of patients with inflammatory bowel disease submitted to surgery

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    BACKGROUND: In the hypothesis that the increased collagen metabolism in the intestinal wall of patients affected by inflammatory bowel disease (IBD) is reflected in the systemic circulation, we aimed the study to evaluate serum level of procollagen III peptide (PIIIP) in peripheral and splanchnic circulation by a commercial radioimmunoassay of patients with different histories of disease. METHODS: Twenty-seven patients, 17 with Crohn and 10 with ulcerative colitis submitted to surgery were studied. Blood samples were obtained before surgery from a peripheral vein and during surgery from the mesenteric vein draining the affected intestinal segment. Fifteen healthy age and sex matched subjects were studied to determine normal range for peripheral PIIIP. RESULTS: In IBD patients peripheral PIIIP level was significantly higher if compared with controls (5.0 ± 1.9 vs 2.7 ± 0.7 μg/l; p = 0.0001); splanchnic PIIIP level was 5.5 ± 2.6 μg/l showing a positive gradient between splanchnic and peripheral concentrations of PIIIP. No significant differences between groups nor correlations with patients' age and duration of disease were found. CONCLUSIONS: We provide evidence that the increased local collagen metabolism in active IBD is reflected also in the systemic circulation irrespective of the history of the disease, suggesting that PIIIP should be considered more appropiately as a marker of the activity phases of IBD

    Treatment of refractory ascites with an automated low-flow ascites pump in patients with cirrhosis.

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    BACKGROUND Refractory ascites (RA) is a frequent complication of cirrhosis, requiring large volume paracentesis or placement of a transjugular intrahepatic portosystemic shunt (TIPSS). The automated low-flow ascites pump (alfapump, Sequana Medical AG, Zurich, Switzerland) is an innovative treatment option for patients with RA. AIM To assess safety and efficacy of this treatment in patients with a contraindication to TIPSS. METHODS Fifty-six patients (43 males; mean age 62 years) from centres in Germany, Switzerland, UK and Spain were included and followed for up to 24 months. Complications, device deficiencies, paracentesis frequency and patient survival were recorded. RESULTS At the time of this analysis, 3 patients completed the 24-month observation period, monitoring of 3 was ongoing, 9 underwent liver transplantation, 17 patients were withdrawn due to serious adverse events and 23 patients died. Most frequently observed technical complication was blocking of the peritoneal catheter. Twenty-three pump-related reinterventions (17 patients) and 12 pump exchanges (11 patients) were required during follow-up. The pump system was explanted in 48% of patients (in 17 patients due to serious adverse events, in 9 at the time of liver transplantation and in 1 due to recovery from RA). Median frequency of paracentesis dropped from 2.17 to 0.17 per month. CONCLUSIONS The alfapump can expand therapeutic options for cirrhotic patients with RA. Continuous drainage of ascites in a closed loop automated system led to significant reduction in paracentesis frequency. Technical and procedural improvements are required to reduce the rate of adverse events and reinterventions. https://clinicaltrials.gov/ct2/show/NCT01532427

    Frequent downregulation of 14-3-3 σ protein and hypermethylation of 14-3-3 σ gene in salivary gland adenoid cystic carcinoma

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    14-3-3 σ, a target gene of the p53 tumour suppressor protein, has been shown to regulate the cell cycle at the G2/M checkpoint. Recent studies have demonstrated that 14-3-3 σ is downregulated by hypermethylation of the CpG island in several types of cancer. In this study, we investigated the expression and methylation status of 14-3-3 σ in human salivary gland adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (MEC). Immunohistochemical analysis revealed that the positive expression rate of 14-3-3 σ in ACC (one out of 14) was markedly lower than that in MEC (ten out of 10). Since most of the ACCs carried the wild-type p53 protein, downregulation of 14-3-3 σ in ACC may not be due to the dysfunction of p53 pathway. Microdissection–methylation-specific PCR revealed that frequent hypermethylation of the 14-3-3 σ gene was observed in ACC when compared to that in MEC. In cultured-ACC cells, we confirmed the downregulation of 14-3-3 σ via hemimethylation of the gene by sequencing analysis after sodium bisulphite treatment. Furthermore, re-expression of 14-3-3 σ in the ACC cells was induced by the treatment with DNA demethylating agent, 5-aza-2′-deoxycytidine. Irradiation apparently induced the enhanced expression of 14-3-3 σ and G2/M arrest in normal salivary gland cells; however, in the ACC cells, neither induction of 14-3-3 σ nor G2/M arrest was induced by irradiation. These results suggest that downregulation of 14-3-3 σ might play critical roles in the neoplastic development and radiosensitivity of ACC

    Processing of Plasmodium falciparum Merozoite Surface Protein MSP1 activates a Spectrin-binding function enabling parasite egress from RBCs

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    The malaria parasite Plasmodium falciparum replicates within erythrocytes, producing progeny merozoites that are released from infected cells via a poorly understood process called egress. The most abundant merozoite surface protein, MSP1, is synthesized as a large precursor that undergoes proteolytic maturation by the parasite protease SUB1 just prior to egress. The function of MSP1 and its processing are unknown. Here we show that SUB1-mediated processing of MSP1 is important for parasite viability. Processing modifies the secondary structure of MSP1 and activates its capacity to bind spectrin, a molecular scaffold protein that is the major component of the host erythrocyte cytoskeleton. Parasites expressing an inefficiently processed MSP1 mutant show delayed egress, and merozoites lacking surface-bound MSP1 display a severe egress defect. Our results indicate that interactions between SUB1-processed merozoite surface MSP1 and the spectrin network of the erythrocyte cytoskeleton facilitate host erythrocyte rupture to enable parasite egress
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