Analysis of some steroids by thin-layer chromatography using optimum mobile phases

The aim of this paper was the analysis of five androstane isomers by thin-layer chromatography (TLC). The choice of proper mobile phase and the optimization of the mobile phase composition are very important because the chromatographic separation is difficult to achieve. In the first step, the proper mobile phase system was chosen from seven elution systems presented in the literature using numerical taxonomy method. The proper solvent system was found to be the mixture of chloroform, acetone, and petroleum ether. In the second step the composition of mobile phase was optimized by "simplex" method and "prisma" method. The optimum TLC system can be applied for the separation of androstane isomers from real samples such as drug formulation, biological and natural sources.     

VO2 Max and Anaerobic Threshold in Hypertension: A Tissue Doppler Study

Background: Hypertension can impair left ventricular (LV) relaxation causing shortness of breath and reduced exercise capacity, which may affect the clinical evaluation of the symptomatic hypertensive patient. In this study we used tissue Doppler imaging (TDI) to identify correlates of anaerobic threshold (AT) and maximum oxygen uptake (VO₂ Max). Our goal was to assess the feasibility of TDI as a surrogate of functional capacity in hypertensive individuals. Methods: We studied subjects without metabolic syndrome and with normal LV function (ejection fraction (EF) >50%) . Traditional echocardiographic variables were obtained before and after a cardiopulmonary exercise test. Systolic (S) and diastolic (E ' and A ' ) myocardial velocities were measured at the basal septal (bs) and posterior (bp) walls. Results: After multivariate analysis, resting E ' bp ( r = 0.56, P < 0.002) and isovolumic relaxation time (IVRT) ( r =− 0.49, I < 0.03) correlated with VO₂ Max, while A Valsalva correlated with AT ( r =− 0.46, P < 0.03) . Peak stress E '/ A ' bp correlated with age and gender corrected METs ( r =− 0.63, P < 0.0004) and VO₂ Max ( r =− 0.39, P< 0.04). Conclusions: Resting E ' bp and peak stress E '/ A ' bp correlate with VO₂ Max in hypertensive patients. TDI may be an important tool when assessing symptoms in this population.     

Comparison of craniofacial morphology in monozygotic twins with their siblings

Lateral cephalometric radiographs from 33 families of monozygotic twins and their siblings were digitized. Eight skeletal parameters were measured: FA to SN, SNA, SNB, ANB, angle of convexity, mandibular plane to SN angle, Y axis and pogonion to NB distance. Monozygotic twin pairs and their siblings showed a normal distribution pattern for all the skeletal parameters, except the pogonion to NB distance measurement. There was found to be a statistically significant correlation between age and facial angle and ANB. A familial aggregation effect was found for SNA, ANB and angle of convexity. Some genetic influence was found for FA, mandibular plane angle and Y axis, while the Pg to NB distance showed neither genetic influence, nor a familial aggregation.     

Small bowel herniation around an anterior gastropexy for a gastric volvulus: a case report.

Gastric volvulus can be a medical emergency with life-threatening complications. Early surgical intervention is important to avoid potential ischemic complication that may lead to infarction of the stomach. The condition has been reported in children and in the elderly, but the majority of cases are reported in the fifth decade of life. We present a case of a complication arising from corrective laparoscopic surgery for gastric volvulus, whereby most of the small bowel herniated around the anterior laparoscopically performed gastropexy. The herniation was reduced during a laparotomy, and the space through which the herniation occurred was closed.     

Development of a drug resistance model for hepatoblastoma

Multidrug resistance (MDR) is a major reason for poor treatment results in hepatoblastoma (HB). The objective of this study was to establish a drug resistance model for HB to analyse alternative treatment options in vitro. Both HB cell lines HUH6 and HepT1 were xenotransplanted in NMRI mice (nu/nu) and 2 cycles of cisplatin (CDDP) treatment were administered. Thereafter, xenotransplants were excised and viable tumour cells were re-cultured. 3D cultures of HUH6 and HepT1 cells were generated on a low binding culture surface. Cell viability in response to CDDP/DOXO (doxorubicin) and apoptosis was assessed by MTT-assay and caspase 3 activity, respectively. Efflux of doxorubicin was measured by flow cytometry. Cellular levels of ABC-transporters (MDR1, MRP1, cMOAT and BRCP) were determined by real time rt-PCR. Only HepT1 cells isolated from HB xenografts showed resistance to CDDP, but did not survive repeated passages. Culturing HUH6 and HepT1 cells as spheroids was successful and 3D cultures showed an IC50-drift to higher drug concentrations for CDDP and DOXO compared to 2D cultures. Treatment with CDDP and DOXO led to homogeneous apoptosis in spheroids. Increased doxorubicin efflux in HUH6 spheroids was not influenced by the P-glycoprotein inhibitor tariquidar. Expression levels of MDR1, MRP1, cMOAT and BRCP in 3D cultures were similar to those in 2D cultures and were higher in HepT1 than in HUH6 cells. In conclusion, a 3D cell culture model for multidrug resistance was established for hepatoblastoma. The underlying mechanism involves altered accessibility of the cells for drugs rather than up-regulation of ABC-transporters.