An open-label randomized trial of the safety and efficacy of sirolimus vs. azathioprine in living related renal allograft recipients receiving cyclosporine and prednisone combination

BACKGROUND: The ability of sirolimus (SRL), in combination with reduced exposure of cyclosporine, was investigated to prevent acute rejection and associated side effects. METHODS: Between June 1999 and February 2000, 70 recipients of primary one-haplotype living-related donor renal allografts were randomized to receive SRL (2 mg/d) or azathioprine (AZA) (2 mg/kg/d) combined with cyclosporine and prednisone. The primary end-point was a composite of first occurrence of biopsy-confirmed acute rejection, graft loss, or death during the first 3 months after transplantation. RESULTS: From week 4 to month 12, SRL patients received lower cyclosporine (week 4: 364 mg/d vs. 455 mg/d, p = 0.004; month 12: 195 mg/d vs. 255 mg/d, p = 0.038) doses and showed lower cyclosporine concentrations (week 4: 247 ng/mL vs. 309 ng/mL, p = 0.04; month 12: 143 ng/mL vs. 188 ng/mL, p = 0.045). Compared with AZA, SRL patients showed reduced 3-month primary end point (0% vs. 17.1%, p = 0.025), and reduced incidence of biopsy-confirmed acute rejection at 3 months (0% vs. 14.3%, p = 0.01) but not at 12 months (11.4% vs. 14.3%, NS). Mean creatinine at 12 months were not different (1.8 +/- 0.6 vs. 1.6 +/- 0.6, p = 0.23). Hyperlipidemia was the only adverse event more frequent among SRL patients (49% vs. 17%, p = 0.01). There were no differences in infections and no malignancies in both groups. CONCLUSIONS: The combination of 2 mg fixed doses of SRL, reduced cyclosporine exposure and prednisone was associated with a low incidence of acute rejection and did not result in significantly impaired graft function compared with patients receiving AZA, standard doses of cyclosporine and prednisone.     

Thomas Hodgkin's journey through Spain in 1863 and 1864

In 1863 and 1864, Thomas Hodgkin travelled to Morocco, accompanying his close friend Sir Moses Montefiore, who stopped in Madrid on the way there and back to attend an audience with the Queen of Spain. Thomas Hodgkin's impressions of Spain were recounted in his book Narrative of a Journey to Morocco. The book reveals new aspects of Hodgkin's personality as well as his capacity for observation. It also describes Spain in the second half of the nineteenth century. Thus Thomas Hodgkin was a witness to one of the most vivid periods of the history of the country. The paper considers both aspects of Hodgkin's commentaries on Spain.     

High-resolution MRI and micro-CT in an ex vivo rabbit anterior cruciate ligament transection model of osteoarthritis

OBJECTIVE: The aim of this study was to investigate the potential of using non-invasive, multi-modality imaging techniques to quantify disease progression in a rabbit model of experimentally induced osteoarthritis (OA). METHODS: High-resolution 4-T magnetic resonance imaging (MRI) and micro-computed tomography (micro-CT) techniques were implemented and validated in an ex vivo rabbit anterior cruciate ligament transection (ACLT) model of OA. A three-dimensional (3-D) rigid body registration technique was executed and evaluated to allow combined MR-CT analysis in co-registered image volumes of the knee. RESULTS: The 3-D MRI and micro-CT data formats made it possible to quantify cartilage damage, joint-space, and osseous changes in the rabbit ACLT model of OA. Spoiled gradient-recalled echo and fast-spin echo (FSE) sequences were jointly used to evaluate femorotibial cartilage and determine the sensitivity (78.3%) and specificity (95.3%) of 4-T MRI to detect clinically significant cartilage lesions. Overall precision error of the micro-CT technique for analysis of joint-space, volumetric bone mineral density (vBMD), and bone volume fraction (BV/TV) was 1.8%, 1.2%, and 2.0%, respectively. Co-registration of the 3-D data sets was achieved to within 0.36 mm for completed intermodality registrations, 0.22 mm for extrapolated intramodality registrations, and 0.50mm for extrapolated intermodality registrations. CONCLUSIONS: These results indicate that high-resolution 4-T MRI and micro-CT can be used to accurately quantify cartilage damage and calcified tissue changes in the rabbit ACLT model of OA. In addition, image volumes can be successfully co-registered to facilitate a comprehensive multi-modality examination of localized changes in both soft tissue and bone within the rabbit femorotibial joint.     

Effects of different sterilization methods on the morphology, mechanical properties, and cytotoxicity of chitosan membranes used as wound dressings

The aim of this work was to compare the effects induced by two different sterilization methods (exposure to gamma radiation or ethylene oxide) and an antiseptic technique (immersion in 70% ethanol aqueous solution) on the morphology, tensile strength, percentage of strain at break, and in vitro cytotoxicity to Vero cells on chitosan membranes designed for wound healing. Four distinct membrane compositions were evaluated, with chitosan, glycerol, and chitin used as components. Gamma radiation, in spite of being one of the most commonly employed sterilizing agents, negatively affected the morphology of membranes composed solely by chitosan as well as the percentage of strain at break of the chitosan-membranes containing glycerol on their composition. Moreover, its use affected the color of the chitosan membranes. The use of 70% ethanol aqueous solution did not change the chitosan-membrane characteristics significantly, but its use has limitations concerning the process scale up. With ethylene oxide (EtO), chitosan-membrane morphology, percentage of strain at break, and in vitro cytotoxicity to Vero cells were not significantly affected. The tensile strength of the membranes containing chitin were reduced after the treatment with ethylene oxide; however, the obtained values were comprised in the range verified for normal human skin. Therefore, because the final characteristics of the membranes treated with ethylene oxide are appropriate when considering their use as wound healing devices, and because this sterilization process is easily adjusted to use on an industrial scale, EtO can be considered the most adequate sterilizing agent for chitosan membranes. However, it should be considered that this chemical is associated with toxicity, flammability, and environmental risks, as well as with possible material contamination with ethylene oxide residues.     

Characterization of connexin 30.3 and 43 in thymocytes

During maturation, thymocytes interact directly and indirectly with different cell types of the thymic microenvironment. Such a cellular communication has been basically ascribed to soluble factors and surface receptors. However, little attention has been given to cellular communication mediated by gap junctions. The existence of these intercellular channels in the immune system remained a controversial issue since the 1970s until recently, when a growing body of evidence has indicated their presence and physiological roles in the immune system. In this work, we investigated whether thymocytes express gap junction-forming proteins (connexins, Cx) and are capable of forming functional intercellular channels. Using RT-PCR, we demonstrated that thymocytes express the mRNA for two Cx isoforms: Cx30.3 and Cx43, but not for Cx26, Cx30, Cx31, Cx31.1, Cx32, Cx33, Cx36, Cx37, Cx40, Cx45, Cx46, and Cx50. In addition, the presence of Cx30.3 and Cx43 was confirmed using different techniques (RNase protection assay, western blot and immunofluorescence). However, despite the expression of these two Cxs, we did not detect functional homocellular coupling between thymocytes or between EL-4 cells (a Cx43 expressing thymic lymphoma-derived cell line) or heterocellular coupling between thymocytes and thymic epithelial cells (TEC) or between EL-4 and TEC in unstimulated conditions. Concluding, in this study, we described for the first time the expression of connexins in thymocytes, which may constitute a new molecule having a functional role in thymocytes maturation.     

Studies on the involvement of the exopolysaccharide produced by cystic fibrosis-associated isolates of the Burkholderia cepacia complex in biofilm formation and in persistence of respiratory infections

Bacteria belonging to the Burkholderia cepacia complex (BCC) are important opportunistic pathogens that lead to respiratory infections in patients with cystic fibrosis (CF). The clinical outcome following colonization with BCC bacteria is highly variable, and so far, unpredictable. A large percentage (80 to 90%) of BCC isolates from CF patients produce the exopolysaccharide (EPS) cepacian, which has been hypothesized to play a role in the colonization and persistence of these bacteria in the CF lung. In this work, we demonstrate that although it is not required for the initiation of biofilm formation, cepacian plays a role in the establishment of thick biofilms. This conclusion was based on a comparison of the abilities of EPS-defective mutants derived from a B. cepacia mucoid CF isolate by random plasposon insertion mutagenesis and the ability of the parental strain to form biofilms. However, the systematic characterization of 108 CF isolates, corresponding to 15 distinct strains, indicated that other strain-dependent factors are also involved in the development of thick, mature biofilms. The isolates examined belonged to the species B. cepacia, B. multivorans, B. cenocepacia, and B. stabilis and were obtained during a 7-year period of surveillance from 21 CF patients receiving care at the major Portuguese CF center. Most of them (90%) were serial isolates from 12 persistently infected patients. In spite of the concept that bacteria growing in biofilms display more resistance to antibiotics and to host phagocyte killing than do planktonically growing cells, no clear correlation could be established between the ability of the various strains examined to produce EPS and/or to form biofilms in vitro and the persistence or virulence of the respiratory infections they caused in different patients.     

Non-toxigenic pattern II and III Bacteroides fragilis strains: coexistence in the same host

Diarrhoeic stool samples from 334 0-5-year-old children were analysed with respect to the incidence of Bacteroides fragilis as well as other enteropathogens. B. fragilis was recovered in 9.3% (31/334) of the samples, and 79 strains were examined for the presence of the bft gene or the BfPAI flanking region using polymerase chain reaction assays. No enterotoxigenic B. fragilis strains were detected. In 29% (9/31) of the samples the coexistence of both II and III non-toxigenic B. fragilis (NTBF) patterns could be seen. In 51.6% (16/31) of the samples there existed a pattern II NTBF only, and in 19.4% (6/31) only pattern III could be detected. Strains from the same patient representing different patterns were submitted to pulsed-field gel electrophoresis assays. Fingerprints obtained by this technique showed that there was strong heterogeneity among strains from different individuals. However, different patterns from the same individual shared 100% similarity.     

Cocrystallization of Blends of Ethylene/1‐Olefin Copolymers: An Investigation with Crystallization Analysis Fractionation (Crystaf)

Summary: Crystallization analysis fractionation (Crystaf) is a technique for estimating the chemical composition distribution (CCD) of semi‐crystalline copolymers. Cocrystallization may happen during Crystaf analysis, affecting Crystaf profiles and leading to misinterpretation of the CCD. This study investigates this phenomenon and determines the main factors leading to cocrystallization by analyzing a series of ethylene/1‐olefin copolymers. We considered three factors affecting cocrystallization: comonomer type, cooling rate and chain crystallizability. The results showed that cooling rate and similarity in chain crystallizability are the key factors regulating cocrystallization during Crystaf analysis.

Crystaf analysis of blends of copolymers.     

Priority for children in cadaveric kidney sharing: the strategy adopted in Sao Paulo, Brazil

Abstract: Early kidney transplantation is crucial in order to accomplish both optimal mental development and the best adult height in children with end‐stage renal disease. The aim was to evaluate the efficacy of the child priority policy for cadaveric kidney sharing adopted in the State of Sao Paulo (Brazil). We performed a retrospective study of data collected by the Government Transplant Department in São Paulo, involving all patients included in the waiting list from August 13, 1998 to December 31, 2001. During the study period, the child priority policy had been changed giving: period A – from the outset up to March 14, 2001, where the rule was to direct cadaveric kidneys obtained from children <12 yr, to recipients <12 yr; period B – from March 14, 2001 onwards, where the policy had been broadened to include cadaveric donors <18 yr, destined for recipients <18 yr. We performed the analysis of the data comprising 8940 patients, 8622 being adults (mean age = 48.6 ± 14.1 yr, 3594 females) and 318 children (mean age = 11.9 ± 5.1 yr, 156 females). Over the 3.5‐yr follow‐up there were 1964 deaths [1933 adults and 31 children, odds ratio (OR) 0.37; 95% CI 0.25–0.55], 1032 living donor kidney transplants (963 adults and 69 children, OR 2.20; 95% CI 1.66–2.93), and 556 cadaveric kidney transplants (444 adults and 112 children, OR 10.11; 95% CI 7.75–12.94). Three and a half years after being enrolled on the list, 24% of the children and 75% of the adults, respectively, were still awaiting a cadaveric kidney transplant (log rank test = 539, p < 0.00001). The analysis of period A vs. period B, suggests that the raising of the inclusion age upper limit to 18 yr, resulted in a twofold increase in the percentage of children being grafted within 6 months of enrollment. Overall, our data shows a slow rate of cadaveric kidney transplantation activity in Sao Paulo. Children's chances of receiving a living donor kidney almost doubled. Moreover, 19.5% of pediatric recipients had received their kidney within the first year of being enrolled on the waiting list. The scheme adopted in Sao Paulo is encouraging, but the results remain less favorable than those observed in other countries. The adoption of the priority policy did not result in an unacceptable increase of adult waiting time, given that the number of adults on our waiting list outweighs by far the number of children.