Response of Cultured Fetal and Adult Rat Hepatocytes to Growth Factors and Cyclosporine

Hepatocyte transplantation is a promising alternative to orthotopic liver transplantation in experimental animal models with genetic disorders of liver metabolism and liver failure. Fetal hepatocytes have several characteristics that make them potentially suitable as donor cells. In contrast to adult hepatocytes, fetal hepatocytes are thought to be highly proliferative, which may facilitate engraftment, expansion of transplanted cell population, and gene transfer requiring active DNA synthesis. The present study was undertaken to evaluate the proliferative capacity of fetal and adult rat hepatocytes under standardized culture conditions. Fetal (20 days of gestation) and adult hepatocytes were cultured in serum-free media at low densities and treated with growth factors. Proliferation was assessed by [3H]-thymidine incorporation and cell cycle analysis by flow cytometry. In nonstimulated cells, DNA synthesis at 4 h was about × 100 higher and after 10 days in culture ×20 higher in fetal compared to adult hepatocytes. When epidermal growth factor (EGF) was added, maximal DNA synthesis in fetal hepatocytes was seen at 48 h, whereas in adult hepatocytes at 72 h. For adult hepatocytes, the average increase compared to untreated cells was × 13.8 with EGF, ×18.5 with transforming growth factor alpha (TGF-α), and ×7.6 with hepatocyte growth factor (HGF). For fetal hepatocytes, the increase was twofold with either EGF, TGF-α or HGF. EGF-, TGF-α- and HGF-dependent DNA synthesis was inhibited by transfroming growth factor beta-1 (TGF-β1) in both fetal and adult hepatocyte cultures; this antiproliferative effect was significantly stronger in adult hepatocyte cultures. With cyclosporine, EGF-, TGF-α- and HGF-dependent DNA synthesis in fetal hepatocyte cultures decreased by 36–46%, whereas in adult hepatocytes by 19–27%. These results show that in contrast to adult hepatocytes, fetal hepatocytes have high spontaneous proliferative activity independently of growth factors and are relatively resistant to the inhibitory effect of TGF-β1. It was also found that cyclosporine suppresses proliferation of cultured fetal hepatocytes.

Distribution of Water in Synthetic Calcium Silicate Hydrates

Understanding calcium silicate hydrates (CSHs) is of paramount importance for understanding the behavior of cement materials because they control most of the properties of these man-made materials. The atomic scale water content and structure have a major influence on their properties, as is analogous with clay minerals, and we should assess these. Here, we used a multiple analytical approach to quantify water distribution in CSH samples and to determine the relative proportions of water sorbed on external and internal (interlayer) surfaces. Water vapor isotherms were used to explain the water distribution in the CSH microstructure. As with many layered compounds, CSHs have external and internal (interlayer) surfaces displaying multilayer adsorption of water molecules on external surfaces owing to the hydrophilic surfaces. Interlayer water was also quantified from water vapor isotherm, X-ray diffraction (XRD), and thermal gravimetric analyses (TGA) data, displaying nonreversible swelling/shrinkage behavior in response to drying/rewetting cycles. From this quantification and balance of water distribution, we were able to explain most of the widely dispersed data already published according to the various relative humidity (RH) conditions and measurement techniques. Stoichiometric formulas were proposed for the different CSH samples analyzed (0.6 < Ca/Si < 1.6), considering the interlayer water contribution.

On the effective solar zenith and azimuth angles to use with measurements of hourly irradiation

Abstract. Several common practices are tested for assessing the effective solar zenith angle that can be associated to each measurement in time-series of in situ or satellite-derived measurements of hourly irradiation on horizontal surface. High quality 1 min measurements of direct irradiation collected by the BSRN stations in Carpentras in France and Payerne in Switzerland, are aggregated to yield time series of hourly direct irradiation on both horizontal and normal planes. Time series of hourly direct horizontal irradiation are reconstructed from those of hourly direct normal irradiation and estimates of the effective solar zenith angle by one of the six practices. Differences between estimated and actual time series of the direct horizontal irradiation indicate the performances of six practices. Several of them yield satisfactory estimates of the effective solar angles. The most accurate results are obtained if the effective angle is computed by two time series of the direct horizontal and normal irradiations that should be observed if the sky were cloud-free. If not possible, then the most accurate results are obtained from using irradiation at the top of atmosphere. Performances show a tendency to decrease during sunrise and sunset hours. The effective solar azimuth angle is computed from the effective solar zenith angle.

A midstream urine collector is not a good alternative to a sterile collection method during the diagnosis of urinary tract infection

AIM

Guidelines recommend collecting urine with suprapubic aspiration or urethral catheterisation in infants with a suspected urinary tract infection (UTI), but the invasiveness of these methods continues to drive research on new urine collection devices. We studied children with a suspected UTI, who had not been toilet trained, to compare a new midstream urine collector and catheterisation.

METHOD

During this prospective controlled diagnosis study of 94 children, urine collection was performed using the midstream collector and then controlled via catheterisation when the urine dipstick was positive.

RESULTS

When end stream samples collected by the midstream collector were compared to catheter samples, the results were inconsistent in 23.4% of cases, similar to the inconsistent results between first stream samples discarded by the device and the catheter samples (21.3%). Interestingly, the overall rate of sample contamination in the bag of the midstream collector was lower than that reported in previously published studies and there were no false positive bag results.

CONCLUSION

The midstream collector did not appear to provide additional benefits to classic collection bags. A sterile collection method, such as suprapubic aspiration, catheterisation or clean catch, is still mandatory for diagnosing urinary tract infections in children who are not toilet trained.

Systematic review with meta-analysis: infliximab and immunosuppressant therapy vs. infliximab alone for active ulcerative colitis

BACKGROUND

The benefit of the combination of infliximab (IFX) and immunosuppressant (IS) therapy is debated in ulcerative colitis (UC).

AIMS

To determine whether the combination of IFX and IS therapy is more effective than infliximab alone for active UC regardless of prior IS use.

METHODS

We identified all controlled trials including patients with moderate-to-severe active UC, treated by either IFX or combined IFX-IS therapy. The main outcome was clinical remission at 4-6 months. Two statistical methods were used, Mantel-Haenszel and Der-Simonian and Laird. Inter-trial heterogeneity was taken into account and publication bias was assessed.

RESULTS

Four controlled trials were analysed and included in the meta-analysis. These four trials included 765 patients, 389 treated with IFX alone and 376 treated with IFX and IS. At 4-6 months' therapy, the clinical remission rate was significantly lower for the IFX monotherapy group OR 0.50, 95% CI [0.34-0.73], P < 0.01 (P-heterogeneity = 0.49). The Harbord test did not show evidence of publication bias (P = 0.29). Calculation of an adjusted OR using the Duval and Tweedie method did not significantly modify results [OR 0.63, 95% CI (0.47-0.85)]. According to Orwin's formula, four additional medium-sized nonsignificant studies would be necessary to reduce the effect size to a nonsignificant value. At 12 months of therapy, there was no significant difference between the two groups: OR 0.60, 95% CI [0.17-2.06], P = 0.41 (P-heterogeneity = 0.01).

CONCLUSION

Combination therapy with IFX-IS is more effective than IFX alone for achieving and maintaining clinical remission at 4-6 months for patients with moderate-to-severe ulcerative colitis, regardless of prior IS use.

Estimating the photosynthetically active radiation under clear skies by means of a new approach

Abstract. The k-distribution method and the correlated-k approximation of Kato et al. (1999) is a computationally efficient approach originally designed for calculations of the broadband solar radiation by dividing the solar spectrum in 32 specific spectral bands from 240 to 4606 nm. This paper describes a technique for an accurate assessment of the photosynthetically active radiation (PAR) from 400 to 700 nm at ground level, under clear-sky conditions using twelve of these spectral bands. It is validated against detailed spectral calculations of the PAR made by the radiative transfer model libRadtran. For the direct and global PAR irradiance, the bias is −0.4 W m−2 (−0.2%) and −4 W m−2 (−1.3%) and the root mean square error is 1.8 W m−2 (0.7%) and 4.5 W m−2 (1.5%). For the direct and global Photosynthetic Photon Flux Density, the biases are of about +10.3 μmol m−2 s−1 (+0.8%) and 1.9 μmol m−2 s−1 (−0.1%) respectively, and the root mean square error is 11.4 μmol m−2 s−1 (0.9%) and 4.0 μmol m−2 s−1 (0.3%). The correlation coefficient is greater than 0.99. This technique provides much better results than two state-of-the-art empirical methods computing the daily mean of PAR from the daily mean of broadband irradiance.

Yearly changes in surface solar radiation in New Caledonia

Abstract. New Caledonia experiences a decrease in surface solar irradiation since 2004. It is of order of 4% of the mean yearly irradiation over the 10 years period: 2004–2013, and amounts to −9 W m−2. The preeminent roles of the changes in cloud cover and to a lesser extent, those in aerosol optical depth on the decrease in yearly irradiation are evidenced. The study highlights the role of data sets offering a worldwide coverage in understanding changes in solar radiation and planning large solar energy plants such as the ICOADS (International Comprehensive Ocean-Atmosphere Data Set) of the NOAA and MACC (Monitoring Atmosphere Composition and Climate) data sets combined with the McClear model.

Early postoperative obstruction after Roux-en-Y gastric bypass

We report a case of early postoperative intestinal obstruction after gastric bypass. The most frequent radiologic presentation is one of gastric dilatation on the CT scan. It is a true surgical emergency.

HAART simplification with lopinavir/ritonavir monotherapy in HIV/HCV co-infected patients starting anti-HCV treatment: a randomised pilot study (KaMon study)

The aim of this randomised, prospective, open-label, multicentre pilot clinical trial was to compare the 48-week toxicity profile of lopinavir/ritonavir (LPV/r) monotherapy with LPV/r-based HAART (KaMon = Kaletra monotherapy) in HIV/HCV patients undergoing HCV treatment. The study involved 30 HIV/HCV co-infected patients naive to anti- HCV therapy. One patient in each arm (6.7%) discontinued anti-HCV therapy because of adverse events. There were no significant between-group differences in terms of the proportion of patients experiencing AEs (p=0.999) or the number of grade 3-4 AEs (p=0.146). No HIV failure was observed. The safety profile of LPV/r monotherapy was similar to that of LPV/r-based HAART, thus encouraging HAART simplification in patients receiving anti-HCV treatment.

Study of the MLB parameterisation for change in surface solar irradiance with sun zenith angle in clear sky

Abstract. The MLB parameterisation (Modified Lambert-Beer, Mueller et al., 2004) describes the change in SSI with sun zenith angle (SZA) in clear-sky conditions. It applies to the direct and global SSI as well as their spectral distribution. We assess its performances by comparing its results to the outputs of the radiative transfer model libRadtran and standard interpolation procedures. The standard two-point fitting MLB function performs very well at SZA between 0° and 60° and fairly bad from 60° to 89.9°. A parameterisation made of four MLBs for four intervals (0°, 60°), (60°, 75°), (75°, 85°) and (85°, 89.9°) is also tested. This piecewise MLB parameterisation exhibits satisfactory performances at any SZA and outperforms standard linear interpolation techniques. 95 % of errors in global SSI are less than 1 W m−2 for each band and less than 5 W m−2 for total irradiance.