Polyunsaturated fatty acids reduce non-receptor-mediated transcellular permeation of protein across a model of intestinal epithelium in vitro

BACKGROUND: Dietary polyunsaturated fatty acids influence the natural history of intestinal inflammatory diseases. Varying the types of long-chain fatty acids that are exposed to cells alters the physicochemical properties of cell membranes. This study aimed to determine whether such variations alter transcellular and paracellular permeability in intestinal epithelium. METHODS: Monolayers of Caco-2 cells, allowed to differentiate by culturing for 7 days following confluence, were used as the model for intestinal epithelium. Paracellular permeability was assessed by measurement of transepithelial resistance, while transcellular permeability was assessed by the transepithelial flux of horseradish peroxidase. RESULTS: Exposure of the cells to 100 micromol/L of palmitic acid, oleic acid, eicosapentaenoic acid, or linoleic acid, was not toxic to cells (measured by leakage of lactate dehydrogenase), and altered cell membrane fatty acid composition (as measured by gas chromatography). Flux of horseradish peroxidase was significantly affected by 24 h fatty acid exposure (P= 0.038, ANOVA), being decreased by 23 +/- 6% (mean +/- SEM) by eicosapentaenoic acid and 25 +/- 3% by linoleic acid. Oleic acid, palmitic acid and butyrate, had no effect. Transepithelial resistance also varied significantly across the treatment groups (P< 0.001) due to a 28 +/- 5% increase induced by butyrate. The long-chain fatty acids had no effect. CONCLUSIONS: Both omega-3 and omega-6 polyunsaturated fatty acids reduce transcellular, non-receptor-mediated permeation of proteins across differentiated Caco2 cell monolayers, without altering paracellular permeability. Alteration of intestinal barrier function should be considered as a possible mechanism of action of dietary polyunsaturated fatty acids.     

Dexamethasone-induced increase in the rate of appearance in plasma of gut-derived glucose following an oral glucose load in rats

Glucocorticoids are known to impair oral glucose tolerance and to induce insulin resistance. It has also been reported that glucocorticoids stimulate absorption of glucose, water, and electrolytes from the gut. The aim of the present study was to determine if dexamethasone treatment increased the rate of appearance in plasma of gut-derived glucose. Glucose turnover was measured following an oral glucose load in chronically catheterized, nonstressed rats treated for 96 hours with either normal saline (n = 14) or dexamethasone (5 micrograms twice daily intravenously [IV] (n = 10). Dexamethasone-treated rats had mild glucose intolerance and higher insulin levels than control rats. Total glucose turnover was increased at all time points following the glucose drink in the dexamethasone-treated rats, as was the rate of appearance of gut-derived glucose (154 +/- 25 v 321 +/- 62 mg/45 min; P = .018). It is concluded that in rats, dexamethasone treatment increases the rate of appearance in plasma of orally administered glucose.     

Identification and characterization of three novel mutations in the CASQ1 gene in four patients with tubular aggregate myopathy

Here, we report the identification of three novel missense mutations in the calsequestrin‐1 (CASQ1) gene in four patients with tubular aggregate myopathy. These CASQ1 mutations affect conserved amino acids in position 44 (p.(Asp44Asn)), 103 (p.(Gly103Asp)), and 385 (p.(Ile385Thr)). Functional studies, based on turbidity and dynamic light scattering measurements at increasing Ca²⁺ concentrations, showed a reduced Ca²⁺‐dependent aggregation for the CASQ1 protein containing p.Asp44Asn and p.Gly103Asp mutations and a slight increase in Ca²⁺‐dependent aggregation for the p.Ile385Thr. Accordingly, limited trypsin proteolysis assay showed that p.Asp44Asn and p.Gly103Asp were more susceptible to trypsin cleavage in the presence of Ca²⁺ in comparison with WT and p.Ile385Thr. Analysis of single muscle fibers of a patient carrying the p.Gly103Asp mutation showed a significant reduction in response to caffeine stimulation, compared with normal control fibers. Expression of CASQ1 mutations in eukaryotic cells revealed a reduced ability of all these CASQ1 mutants to store Ca²⁺ and a reduced inhibitory effect of p.Ile385Thr and p.Asp44Asn on store operated Ca²⁺ entry. These results widen the spectrum of skeletal muscle diseases associated with CASQ1 and indicate that these mutations affect properties critical for correct Ca²⁺ handling in skeletal muscle fibers.     

Robust Intensity Standardization in Brain Magnetic Resonance Images

The paper is focused on a tiSsue-Based Standardization Technique (SBST) of magnetic resonance (MR) brain images. Magnetic Resonance Imaging intensities have no fixed tissue-specific numeric meaning, even within the same MRI protocol, for the same body region, or even for images of the same patient obtained on the same scanner in different moments. This affects postprocessing tasks such as automatic segmentation or unsupervised/supervised classification methods, which strictly depend on the observed image intensities, compromising the accuracy and efficiency of many image analyses algorithms. A large number of MR images from public databases, belonging to healthy people and to patients with different degrees of neurodegenerative pathology, were employed together with synthetic MRIs. Combining both histogram and tissue-specific intensity information, a correspondence is obtained for each tissue across images. The novelty consists of computing three standardizing transformations for the three main brain tissues, for each tissue class separately. In order to create a continuous intensity mapping, spline smoothing of the overall slightly discontinuous piecewise-linear intensity transformation is performed. The robustness of the technique is assessed in a post hoc manner, by verifying that automatic segmentation of images before and after standardization gives a high overlapping (Dice index >0.9) for each tissue class, even across images coming from different sources. Furthermore, SBST efficacy is tested by evaluating if and how much it increases intertissue discrimination and by assessing gaussianity of tissue gray-level distributions before and after standardization. Some quantitative comparisons to already existing different approaches available in the literature are performed.     

Surgical complications due to postnatal cytomegalovirus infection in a preterm infant with malrotation

We report a case of an extremely preterm infant with intestinal malrotation who contracted postnatal systemic cytomegalovirus (CMV) infection with a complicated intestinal evolution requiring repeated surgical interventions and antiviral treatment. This report is to emphasize that prolonged gastrointestinal symptoms in extremely preterm infants fed with non‐pasteurized breast milk should lead to suspicion of CMV infection. The importance of preventive measures when feeding very preterm infants with breast milk needs to be considered. Furthermore, the indications for antiviral treatment, in particular in preterm infants, need to be clarified.     

Intrafollicular expression of matrix metalloproteinases and their inhibitors in normally ovulating women compared with patients undergoing in vitro fertilization treatment

OBJECTIVE: To assess possible differences in the activity of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, and their inhibitors, the tissue inhibitors of MMPs, TIMP-1 and TIMP-2, in follicular fluid (FF) of women undergoing in vitro fertilization (IVF) treatment and of normally ovulating women. DESIGN: Prospective study. METHODS: MMP-2 and MMP-9 activity was analyzed by gelatin zymography and MMP-2, MMP-9, TIMP-2, TIMP-1 and 17beta-estradiol levels were measured in FF by ELISA. RESULTS: We found significantly reduced MMP levels in FF of women undergoing IVF treatment when compared with those of normally ovulating women. In contrast, the TIMP-1 levels were found significantly increased in FF from IVF patients vs normally ovulating women. No significant differences were found for TIMP-2 between the two groups. CONCLUSIONS: These findings underline a marked difference in MMPs and their inhibitors in the IVF women and the control group. Therefore we assume MMPs depend on hormonal steroidogenesis modulation induced by the gonadotropin protocol for IVF treatment.     

Drug‐resistant tuberculosis: Past,present, future

In a population of Mycobacterium tuberculosis, random chromosomal mutation that results in genetic resistance to anti‐tuberculosis (TB) drugs occurs at a relatively low frequency. Anti‐TB drugs impose selection pressure so that mycobacterial mutants gradually outnumber susceptible bacilli and emerge as the dominant strains. Resistance to two or more anti‐TB drugs represents cumulative results of sequential mutation. The fourth report on global anti‐TB drug resistance provides the latest data on the extent of such problem in the world. The median prevalence of multi‐drug‐resistant TB (MDR‐TB) in new TB cases was 1.6%, and in previously treated TB cases 11.7%. Of the half a million MDR‐TB cases estimated to have emerged in 2006, 50% were in China and India. The optimal duration of any given combination of anti‐TB drugs for treatment of MDR‐ and extensively drug‐resistant TB (XDR‐TB) has not been defined in controlled clinical trials. Standardized treatment may be feasible for MDR‐TB patients not previously treated with second‐line drugs, but a different strategy needs to be applied in the treatment of MDR‐TB patients who have received second‐line drugs before. Unfortunately, the reliability of drug susceptibility testing of most second‐line anti‐TB drugs is still questionable. Drug‐resistant TB is not necessarily less virulent. Findings from modelling exercise warned that if MDR‐TB case detection and treatment rates increase to the World Health Organization target of 70%, without simultaneously increasing MDR‐TB cure rates, XDR‐TB prevalence could increase exponentially. Prevention of development of drug resistance must be accorded the top priority in the era of MDR‐/XDR‐TB.     

Chrysin-induced apoptosis is mediated through p38 and Bax activation in B16-F1 and A375 melanoma cells

Chrysin (5,7-dihydroxyflavone) is a natural and biologically active compound extracted from honey, plants and propolis. It possesses anti-inflammatory activity, anti-oxidant properties and promotes cell death by perturbing cell cycle progression. In this study, our attention focused on the possible role that chrysin may have as a potential anti-cancer agent, and we tested its biological activity in murine and human melanoma cell lines (B16-F1 and A375). This study demonstrated that chrysin reduced melanoma cell proliferation and induced cell differentiation in both human and murine melanoma cells through synthesis increase and intracellular accumulation of protoporphirin IX (PpIX). Furthermore, following treatments with chrysin an increase in the expression of porphobilinogen deaminase (PBG-D) was noted. This study demontrated also that chrysin induces cell death in human and murine melanoma cells through caspase-dependent mechanisms, involving down-regulation of ERK 1/2, and activation of p38 MAP kinases. Induction of cell death may be a promising therapeutic approach in cancer therapy. Our results suggest that chrysin may be considered a potential candidate for both cancer prevention and treatment.     

Urine telomerase activity for the detection of bladder cancer in females

PURPOSE: Previous studies have shown that telomerase activity in bladder washings and voided urine represents an important noninvasive tool for bladder cancer diagnosis. With the present case-control study conducted on 212 women, including 144 healthy individuals and 68 patients, at first diagnosis of bladder cancer we confirmed previously obtained diagnostic results and improved the accuracy of this diagnostic assay. MATERIALS AND METHODS: Telomerase activity was evaluated by quantitative telomeric repeat amplification protocol assay and expressed as arbitrary enzymatic units. RESULTS: At the best overall cutoff of 50 arbitrary enzymatic units sensitivity was 87% and specificity was 66%. A breakdown analysis as a function of age showed a higher assay accuracy in women younger than 75 years (sensitivity 91% and specificity 69%) compared to older women (sensitivity 64% and specificity 59%). CONCLUSIONS: Other reasons in addition to age may account for the lower specificity in women with respect to men. In particular, a high number of telomerase positive nonurothelial cells in urine from females could be responsible for false-positive telomeric repeat amplification protocol results. Urine telomerase activity detected by telomeric repeat amplification protocol appears to be a good diagnostic tool in females although it is more accurate in younger than in older women.