Spontaneous bilayer wrapping of virus particles by a phospholipid Langmuir monolayer.

We report here the spontaneous formation of lipid-bilayer-wrapped virus particles, following the injection of "naked" virus particles into the subphase of a Langmuir trough with a liquid monolayer of lipids at its air-water interface. The virus particles are those of the well-studied cowpea chlorotic mottle virus, CCMV, which are negatively charged at the pH 6 of the subphase; the lipids are a 9:1 mix of neutral DMPC and cationic CTAB molecules. Before adding CCMV particles to the subphase we establish the mixed lipid monolayer in its liquid-expanded state at a fixed pressure (17.5 mN/m) and average area-per-molecule of (41Å2). Keeping the total area fixed, the surface pressure is observed to decrease at about 15 h after adding the virus particles in the subphase; by 37 h it has dropped to zero, corresponding to essentially all the lipid molecules having been removed from the air-water interface. By collecting particles from the subphase and measuring their sizes by atomic force microscopy, we show that the virus particles have been wrapped by lipid bilayers (or by two lipid bilayers). These results can be understood in terms of thermal fluctuations and electrostatic interactions driving the wrapping of the anionic virus particles by the cationic lipids. Spontaneous acquisition by a virus particle of, first, a hydrophobic lipid monolayer envelope and, then, a hydrophilic lipid bilayer envelope, as it interacts from the subphase with an oppositely charged Langmuir monolayer.

Nanotubols under H2O2 exposure: is it possible to poly-hydroxylate carbon nanotubes?

We present a combined experimental and theoretical study dedicated to analyze the variations in the surface chemistry of hydroxylated multiwalled carbon nanotubes (MWCNTs), so called nanotubols, when exposed to H2O2 at high temperatures. The formation, surface density, and distribution of oxygen-containing functional groups are studied by infrared (IR) and X-ray photoelectron spectroscopy (XPS), as well as density functional theory (DFT) calculations performed on model functionalized carbon nanotubes (CNTs). After H2O2 exposure, the initial composition of -OH, -C[double bond, length as m-dash]O, and -COOH substituents notably changes, with carbonyl -C[double bond, length as m-dash]O groups being the ones that show the most notable increase on the carbon surface. Our highly oxidized MWCNTs are partially soluble and form complex two-dimensional patterns at the air-water interface, as evidenced by Brewster angle microscopy. In a second step, these films can be transferred to solid substrates to form porous multilayered carbon nanostructures with complex morphologies. In particular, and for the first time, we report the synthesis of "stadium-like" configurations made of MWCNT units whose formation and stability are a direct consequence of the self-assembly process occurring at the air/water interface. DFT calculations suggest the formation of molecular islands of oxygen-containing functional groups on the CNT surface. In addition, nudged elastic band studies reveal that, for these adsorbed phases, the reaction between two neighboring OH groups to produce atomic oxygen and a physisorbed water molecule is characterized by energy barriers of ∼0.2 eV. These small values could be at the origin of the sizable increase in chemisorbed single-oxygen species determined by XPS data after H2O2 treatment at 60 °C. The simulation of the C 1s binding energies (BE) allows us to more clearly identify the different oxygen-containing functionalities as well as to reveal how the local atomic environment affects their characteristic BEs. Even if we were unable to polyhydroxylate our carbon nanotubes, we believe that H2O2-treated MWCNTs are interesting materials for more complex post-functionalization procedures that might lead to the fabrication of novel carbon nanostructures.

Structure, electronic properties, and aggregation behavior of hydroxylated carbon nanotubes.

We present a combined experimental and theoretical study to analyze the structure, electronic properties, and aggregation behavior of hydroxylated multiwalled carbon nanotubes (OH-MWCNT). Our MWCNTs have average diameters of ~2 nm, lengths of approximately 100-300 nm, and a hydroxyl surface coverage θ~0.1. When deposited on the air/water interface the OH-MWCNTs are partially soluble and the floating units interact and link with each other forming extended foam-like carbon networks. Surface pressure-area isotherms of the nanotube films are performed using the Langmuir balance method at different equilibration times. The films are transferred into a mica substrate and atomic force microscopy images show that the foam like structure is preserved and reveals fine details of their microstructure. Density functional theory calculations performed on model hydroxylated carbon nanotubes show that low energy atomic configurations are found when the OH groups form molecular islands on the nanotube's surface. This patchy behavior for the OH species is expected to produce nanotubes having reduced wettabilities, in line with experimental observations. OH doping yields nanotubes having small HOMO-LUMO energy gaps and generates a nanotube → OH direction for the charge transfer leading to the existence of more hole carriers in the structures. Our synthesized OH-MWCNTs might have promising applications.

Controlling the surface charge of simple viruses.

The vast majority of plant viruses are unenveloped, i.e., they lack a lipid bilayer that is characteristic of most animal viruses. The interactions between plant viruses, and between viruses and surfaces, properties that are essential for understanding their infectivity and to their use as bionanomaterials, are largely controlled by their surface charge, which depends on pH and ionic strength. They may also depend on the charge of their contents, i.e., of their genes or-in the instance of virus-like particles-encapsidated cargo such as nucleic acid molecules, nanoparticles or drugs. In the case of enveloped viruses, the surface charge of the capsid is equally important for controlling its interaction with the lipid bilayer that it acquires and loses upon leaving and entering host cells. We have previously investigated the charge on the unenveloped plant virus Cowpea Chlorotic Mottle Virus (CCMV) by measurements of its electrophoretic mobility. Here we examine the electrophoretic properties of a structurally and genetically closely related bromovirus, Brome Mosaic Virus (BMV), of its capsid protein, and of its empty viral shells, as functions of pH and ionic strength, and compare them with those of CCMV. From measurements of both solution and gel electrophoretic mobilities (EMs) we find that the isoelectric point (pI) of BMV (5.2) is significantly higher than that of CCMV (3.7), that virion EMs are essentially the same as those of the corresponding empty capsids, and that the same is true for the pIs of the virions and of their cleaved protein subunits. We discuss these results in terms of current theories of charged colloidal particles and relate them to biological processes and the role of surface charge in the design of new classes of drug and gene delivery systems.

Interaction of the cationic peptide bactenecin with phospholipid monolayers at the air-water interface: i interaction with 1,2-dipalmitoyl-sn-glycero-3-phosphatidilcholine.

In this work we have investigated the influence of NaCl on the adsorption of the antimicrobial cationic peptide bactenecin in the monolayer of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) at the air-water interface, as a function of NaCl concentrations in the subphase. We show that the effect of the salt concentration on DPPC monolayers is a monotonic decrease of the liquid-condensed-liquid-expanded (LC-LE) coexistence region. By contrast, the effect of the bactenecin adsorption at the DPPC monolayer not only removed the LC-LE coexistence region plateau, but also shifted the DPPC isotherms to higher pressures and increased the compressibility of the DPPC/bactenecin monolayers with respect to the pure DPPC monolayer around the LC phase. Analysis of the domain structure, obtained by Brewster angle and atomic force microscopes, indicates that the salt concentration in the subphase builds an electrostatic barrier, increasing the rigidity of DPPC monolayers and limiting the bactenecin adsorption at the LC-LE phase coexistence.

Phase diagram of self-assembled viral capsid protein polymorphs.

We present an experimental study of the self-assembly of capsid proteins of the cowpea chlorotic mosaic virus (CCMV), in the absence of the viral genome, as a function of pH and ionic strength. In accord with previous measurements, a wide range of polymorphs can be identified by electron microscopy, among them single and multiwalled shells and tubes. The images are analyzed with respect to size and shape of aggregates, and evidence is given that equilibrium has been achieved, allowing a phase diagram to be constructed. Some previously unreported structures are also described. The range and stability of the polymorphs can be understood in terms of electrostatic interactions and the way they affect the spontaneous curvature of protein networks and the relative stabilities of pentamers and hexamers.

[Long-term paratesticular leiomyosarcoma. Conceptual and literature review]. / Leiomiosarcoma paratesticular de larga evolución. Revisión conceptual y de la literatura.

INTRODUCTION: To know the incidence and clinical and pathologic characteristics of the paratesticular leiomyosarcoma (LMS) with the contribution of a case of long evolution, studying the histopathologic criteria that must be valued for this type of tumours. MATERIAL AND METHODS: A 73-year-old patient includes for study with scrotal tumour present left side for 30 months. Histopathologic and imunohistochemical study is realized. Of equal form there is realized a bibliographical search of this type of tumours and their different subtypes across Medline and of not index-linked search. RESULTS: Our case is the second of greater evolution of international literature, first in greater of 60 years and one of those of smaller mitotic index (1 x 50 cga). Nevertheless, his atipia, tumorlike necrosis next to 50% of the injury and its pleomorphic properties, as well as his inmunophenotypic characterization corresponds with a well differentiated LMS, degree 1 (French Federation Cancer). We have found only 107 published cases of this type of sarcomas, of them 5 in our country, which gives to a profile of the low incidence of these tumours, that within sarcomas 1% do not reach. We included the clinical and pathologic profile of such. CONCLUSIONS: The long evolution of a paratesticular tumour and the absence of metastasis does not exclude its malignancy. The low incident of the LMSs in this location, implies that a protocol of actuation validate for such does not exist. We considered of great importance, its creation on the part of urologist, oncologists, radiologists and pathologists like he took control of located in retroperitoneal cavity and deep soft tissues.

[Epididymis trombosed hemangioma in old patient. Presentation of 1 case with conceptual review and of the literature]. / Hemangioma epididimario trombosado en paciente mayor. Presentación de 1 caso con revisión conceptual y de la literatura.

INTRODUCTION: Though theoretically in the paratesticular region one can develop any type of benign tumour of soft tissues, they are the lipomas, leiomyomas and adenomatoid tumours the most usual whereas the hemangiomas are less common. We contribute a new case of epididymis intrascrotal hemangioma (HI), valuing the bibliography that allows us to know the incidence and clinic-pathologic characteristics of these tumours. MATERIAL AND METHOD: A 74-year-old patient includes for study with right scrotal tumour, who is practised orchiectomy. Hystopathologic study is realized. Of equal form there is realized a bibliographical examination of this type of tumours across Medline and of not index-linked search with conceptual review and of the literature. RESULTS: The injury corresponds with a HI cavernous trombosed of epididymis with testicular parenchyma respected. Your hystopathologic diagnosis does not present problems, whereas the clinical one and ultrasonographic study, reaches the whole spectrum of tumours, benign and malignant of soft tissues. The number of intrascrotal hemangiomas of epididymis described in the literature is very limited. CONCLUSIONS: The scrotal tumours are necessary a preoperatory clinical and sonographic study completely, in spite of the fact that they are diagnosed the majority after your surgical removal. The complex system of the tissues on the zone paratesticular implies that the differential enclosed diagnosis does not allow to differentiate, malignant tumours of benign. The low incident of many of these masses has determined the mistake of standardized protocols for your diagnosis but also for their unified treatment.

Initial Experience in the Use of Novel Auto-expandable Metal Ureteral Stent in the Treatment of Ureter Stenosis in Kidney Transplanted Patients.

INTRODUCTION: Ureter stenosis in renal transplantation patients is a relatively frequent complication that negatively conditions graft evolution. The use of ureteral stents is a valid treatment alternative to the use of double-J catheters in patients for whom surgery is not contemplated or after surgical recurrence. We present our initial experience with five patients treated using this technique. MATERIALS AND METHODS: We describe a total of five patients with ureteral stenosis after renal transplantation who were treated using ureteral stent model UVENTA (Taewoong Medical, Seoul, Korea) in our center. The median follow-up was 18 months (range, 4 to 38 months). We describe the clinical history of patients and previous treatments on ureteral stenosis. The technical procedure of placement is described. The clinical course is analyzed by measurement of renal function and imaging tests, as well as post-stent complications. Survival of the renal graft is evaluated. RESULTS: The procedure could be completed in all patients without complications. The technique was effective in all patients, with correction of creatinine value and hydronephrosis during the renal ultrasound test. One patient suffered a urinary tract infection episode associated with the use of the ureteral stent. One patient suffered the loss of the renal graft secondary to the development of cryoglobulins. One hundred percent of the ureteral stents are functioning as of the writing of this article. CONCLUSIONS: In renal transplantation patients with ureter stenosis, metallic stents are a useful technique with low morbidity and associated complications.

Interaction of N-nitrosodiethylamine/bovine serum albumin complexes with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine monolayers at the air-water interface.

We report the effect of N-nitrosodiethylamine (NDA) on the interaction between bovine serum albumin (BSA) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine monolayers (DPPC) at the air-water interface. We prepared aqueous solutions of NDA/BSA complexes maintaining a constant concentration of BSA of 1.49 x 10(-9) M and using NDA concentrations to obtain 2000, 4000, 6000, 12,500, and 25,000 NDA/BSA molar ratios. The hysteresis area and the compressional modulus of the compression-expansion cycles performed at different times were dependent on the NDA concentration. The cycles performed demonstrate the stability of the new phase of DPPC/BSA and DPPC/NDA/BSA monolayers. This was achieved probably because the BSA concentration used was lower than the one needed for BSA to inhibit the return of DPPC molecules to the interface. Results of the compressional modulus at the onset of the new phase, obtained around 17 mN/m, 15 min and 1, 3, 5, and 12 h after DPPC deposition, indicated that the 3.0 x 10(-6) M NDA concentration produced a more rigid film, probably due to the higher alpha-helix content of BSA. AFM images were obtained for DPPC/BSA and two DPPC/NDA/BSA complexes. Our images show that 12,500 NDA/BSA molecules were mostly adsorbed in the liquid condensed phase. However, BSA molecules were distributed more homogeneously.

Current issues in implementing do-not-resuscitate orders for cardiac patients. / Problemática actual en la implementación de la orden de no reanimar en el paciente cardiológico.

Cardiovascular diseases are still the most common cause of death, and heart failure is the most common reason for hospitalization of patients older than 65 years. However, Cardiology attributes low importance to end-of-life care. Cardiac patients' perception of their disease's prognosis and the results of cardiopulmonary resuscitation differ greatly from reality. The "do not resuscitate" order allows patients to pre-emptively express their rejection for cardiopulmonary resuscitation, thereby avoiding its potentially negative consequences. However, these orders are still underused and misinterpreted in cardiac patients. Most of these patients usually have no opportunity to have the necessary conversations with their attending physician on their resuscitation preferences. In this review, we performed an analysis of the causes that could explain this situation.

Encapsidated ultrasmall nanolipospheres as novel nanocarriers for highly hydrophobic anticancer drugs.

The design and construction of novel nanocarriers that have controlled shape and size and are made of inherently biocompatible components represents a milestone in the field of nanomedicine. Here, we show the tailoring of nanoliposphere-like particles for use as biocompatible drug nanocarriers. They are made with the building block components present in human lipoproteins by means of microfluidization, which allows for good size and polydispersity control, mimicking the physical properties of natural low-density lipoproteins (LDLs). This new type of nanocarrier has a negative surface charge and a hydrophobic core that allow the stabilization and encapsulation of hydrophobic anticancer drugs such as camptothecin, resulting in anticancer drug-loaded nanolipospheres. However, we found that the nanoparticles are unstable since their size increases with time. These nanolipospheres were further encapsidated using the non-cytotoxic capsid protein of the plant virus CCMV, which renders the nanoparticles stable. In a more general application, this new virus-like particle confers a controlled microenvironment for the transport of any kind of hydrophobic drug that can bypass the cellular defense mechanisms and deliver its payload.

Expression of proteins FGFR3, PI3K, AKT, p21Waf1/Cip1 and cyclins D1 and D3 in patients with T1 bladder tumours: clinical implications and prognostic significance. / Expresión de las proteínas FGFR3, PI3K, AKT, p21Waf1/Cip1 y ciclinas D1 y D3 en pacientes con tumores de vejiga T1: implicaciones clínicas y significado pronóstico.

OBJECTIVE: To determine the differential protein expression of biomarkers FGFR3, PI3K (subunits PI3Kp110α, PI3KClassIII, PI3Kp85), AKT, p21Waf1/Cip1 and cyclins D1 and D3 in T1 bladder cancer versus healthy tissue and to study their potential role as early recurrence markers. MATERIAL AND METHOD: This is a prospective study that employed a total of 67 tissue samples (55 cases of T1 bladder tumours that underwent transurethral resection and 12 cases of adjacent healthy mucosa). The protein expression levels were assessed using Western blot, and the means and percentages were compared using Student's t-test and the chi-squared test. The survival analysis was conducted using the Kaplan-Meier method and the log-rank test. RESULTS: Greater protein expression was detected for FGFR3, PI3Kp110α, PI3KClassIII, cyclins D1 and D3 and p21Waf1/Cip1 in the tumour tissue than in the healthy mucosa. However, these differences were not significant for PI3Kp85 and AKT. We observed statistically significant correlations between early recurrence and PI3Kp110α, PI3KClassIII, PI3Kp85 and AKT (P=.003, P=.045, P=.050 and P=.028, respectively), between the tumour type (primary vs. recurrence) and cyclin D3 (P=.001), between the tumour size and FGFR3 (P=.035) and between multifocality and cyclin D1 (P=.039). The survival analysis selected FGFR3 (P=.024), PI3Kp110α (P=.014), PI3KClassIII (P=.042) and AKT (P=.008) as markers of early-recurrence-free survival. CONCLUSIONS: There is an increase in protein expression levels in bladder tumour tissue. The overexpression of FGFR3, PI3Kp110α, PI3KClassIII and AKT is associated with increased early-recurrence-free survival for patients with T1 bladder tumours.

Prognostic value of penile colour doppler ultrasonography for recovering erectile function after radical prostatectomy. / Valor pronóstico de la ecografía doppler color peneana en la recuperación de la función eréctil tras prostatectomía radical.

OBJECTIVE: To analyse the predictive utility of penile colour Doppler ultrasonography after the injection of vasoactive agents for recovering erectile function after radical prostatectomy. MATERIAL AND METHODS: A retrospective study was conducted on patients with erectile dysfunction after radical prostatectomy who were treated with intracavernous injections of prostaglandins E1 between January 1, 2006 and December 31, 2012. The study included patients with no history of erectile dysfunction prior to the surgery and who did not respond to medical treatment. Colour Doppler was performed on all patients after the intracavernous injection. A peak systolic velocity ≥30cm/sec and an end diastolic velocity ≤5cm/sec were considered normal haemodynamic values. We assessed the result of the treatment during the follow-up using the International Index of Erectile Function-5. RESULTS: We included 197 patients. The mean age was 60.8 (±6.3). The pathological diagnosis for all patients was adenocarcinoma, 74.1% of which were confined to the organ (T1-T2/Nx-N0). Treatment with injections after the surgery was started after a mean duration of 6.8 months (+3.5). The Doppler ultrasonography results were normal for 53 patients (26.9%). During the follow-up, 113 patients (57.4%) maintained functional erections; 55 of these patients (28%) did not require injections. Normal Doppler ultrasonography results were associated with a favourable response to treatment (p<.01). CONCLUSIONS: The prostaglandin E1 test will help provide a diagnosis in erectile dysfunction for patients who have undergone prostatectomies. The test helps provide information on the vascular condition of the penis and useful prognostic information for the follow-up of these patients.

Synthesis and characterization of extremely small gold nanoshells, and comparison of their photothermal conversion capacity with gold nanorods.

The current methods for preparing gold nanoshells (AuNSs) produce shells with a diameter of approximately 40 nm or larger, with a relatively large polydispersity. However, AuNSs with smaller diameters and more monodispersity are better suited for biomedical applications. In this work, we present a modified method for the preparation of AuNSs, based on the use of sacrificial silver nanoparticles (AgNPs). We customized the Lee-Meisel method to prepare small and monodisperse AgNPs that were used as sacrificial nanoparticles to prepare extremely small monodispersed AuNSs with an average diameter from 17 to 25 ± 4 nm. We found that these AuNSs are faceted, and that the oxidized silver likely dissolves out of the nanoparticles through some of the facets on the AuNSs. This leads to a silver oxide plug on the surface of the AuNSs, which has not been reported before. The smaller AuNSs, prepared under the best conditions, absorb in the near infrared region (NIR) that is appropriate for applications, such as photothermal therapy or medical imaging. The AuNSs showed absorption peaks in the NIR similar to those of gold nanorods (AuNRs) but with better photothermal capacity. In addition, because of their negative charge, these AuNSs are more biocompatible than the positively charged AuNRs. The synthesis of small, monodisperse, stable and biocompatible nanoparticles, like the ones presented in this work, is of prime importance in biomedical applications.

Prostate Cancer Patients-Negative Biopsy Controls Discrimination by Untargeted Metabolomics Analysis of Urine by LC-QTOF: Upstream Information on Other Omics.

The existing clinical biomarkers for prostate cancer (PCa) diagnosis are far from ideal (e.g., the prostate specific antigen (PSA) serum level suffers from lack of specificity, providing frequent false positives leading to over-diagnosis). A key step in the search for minimum invasive tests to complement or replace PSA should be supported on the changes experienced by the biochemical pathways in PCa patients as compared to negative biopsy control individuals. In this research a comprehensive global analysis by LC-QTOF was applied to urine from 62 patients with a clinically significant PCa and 42 healthy individuals, both groups confirmed by biopsy. An unpaired t-test (p-value < 0.05) provided 28 significant metabolites tentatively identified in urine, used to develop a partial least squares discriminant analysis (PLS-DA) model characterized by 88.4 and 92.9% of sensitivity and specificity, respectively. Among the 28 significant metabolites 27 were present at lower concentrations in PCa patients than in control individuals, while only one reported higher concentrations in PCa patients. The connection among the biochemical pathways in which they are involved (DNA methylation, epigenetic marks on histones and RNA cap methylation) could explain the concentration changes with PCa and supports, once again, the role of metabolomics in upstream processes.

Graft Survival in Patients Who Received Second Allograft, Comparing Those With or Without Previous Failed Allograft Nephrectomy.

INTRODUCTION: Nowadays, the number of patients receiving a second graft is growing, and the management of failed grafts is still controversial. OBJECTIVE: Our objective was to analyze the influence of graft nephrectomy on graft and patient survival. MATERIALS AND METHODS: We retrospectively evaluated the demographic features and graft outcomes of 63 recipients who received second allografts between August 1985 and April 2013. They were divided into two groups: group A, those who underwent nephrectomy of failed graft (n = 21, 33.3%), and group B, those whose failed graft was retained (n = 42, 66.6%). χ2 and Mann-Whitney U tests were used to compare demographic characteristics and graft features in both groups. Kaplan-Meier test was used to analyze graft and patient survival. Finally, univariate and multivariate analysis was done using Cox regression. RESULTS: Demographic characteristics of donor and receptors were similar in both groups. Overall panel-reactive antibody (P = .040) showed statistically significant differences between groups (72.0 ± 25.3 in group A and 54.8 ± 30.0 in group B). Hemodialysis duration was longer in group A (P = .023, 112.2 ± 72.8 vs 70.9 ± 66.9 months). The percentage of patients who had delayed graft function was higher in group A (58.8% vs 27.3%, P = .029). Kaplan-Meier test found no differences between groups (P = .344); group A, 107.4 months (95% confidence interval [CI] 74.0 to 140.8) and group B, 82.7 months (95% CI 62.5 to 102.8). We found no differences in terms of patient survival (P = .798) with the Kaplan-Meier test. In group A, patient survival was 164.5 months (CI 137.7 to 191.31) and in group B, 152.0 months (95% CI 125.5 to 178.5). CONCLUSIONS: Failed graft nephrectomy did not show a negative impact on graft and patient survival.

Influence of Donor and Recipient Ages in Survival of Simultaneous Pancreas-Kidney Transplantation.

INTRODUCTION: Simultaneous pancreas-kidney transplantation (SPKT) is a well treatment for patients with insulin-dependent diabetes and end-stage renal disease. Donor age is a barrier to the acceptance of organs. Age matching has been extensively studied in kidney transplantation; however, there are no studies in graft survival after SPKT. We aimed to study the combined influence of the ages of the donors and recipients in graft survival after SPKT. MATERIAL AND METHODS: Donors and recipients are classified as younger (age <40 years) or older (age ≥40 years). There were four study groups (young-young, young-old, old-young, and old-old). They were evaluated retrospectively for demographic and clinical characteristics of donors and recipients and the long-term survival between 2001 and 2012 of kidney pancreas transplantation patients at our center. RESULTS: A total of 115 transplantations were performed. The four groups had 55 young-young, 40 young-old, 10 old-young, and 10 old-old patients. Serious complications occurred in 32%, 42%, 30%, and 40%, respectively, and deaths were 2%, 5%, 0%, and 20%, respectively, in the groups. Pancreas graft survival at 3 years for each group was 80%, 87, 5%, 90%, and 60%, respectively, and kidney graft survival was 92.7%, 90%, 90%, and 70%, respectively. Panel-reactive antibodies (PRAs) >30% were associated with poor graft survival, and serious postoperative complications associated with poor pancreas-kidney graft survival. CONCLUSIONS: In conclusion, both younger and older recipients show excellent long-term graft and patient survival after SPKTs from younger donors. We recommended that older-recipient SPKT be transplanted from younger donors because older recipients who have been transplanted from older donors had decreased survival.

Validation of the Pancreatic Donor Risk Index in Simultaneous Pancreas-Kidney Transplantation Performed in Córdoba Hospital From 2000 to 2015.

BACKGROUND: The Pancreatic Donor Risk Index (PDRI) was developed in 2010 in the United States to predict graft survival after pancreas transplantation, based on donor characteristics and logistical and technical conditions. The aim of the study was to validate the utility of PDRI as a pancreas allograft survival predictor in simultaneous pancreas-kidney transplantation (SPK) transplants performed in our hospital between 2000 and 2015. METHODS: This retrospective analysis of 126 SPK transplants was performed by the same surgical team from the years 2000 to 2015. Donor variables that are integrated in the PDRI were calculated (age, sex, race, creatinine serum levels, body mass index, height, cold ischemia time, cause of death, type of pancreas transplant). Pancreatic graft survival at 1 and 5 years was calculated by use of the Kaplan-Meier test. Comparison of survival curves between PDRI risk quartiles was calculated by use of the log-rank test. Association between graft survival and variables integrating the PDRI was calculated by use of univariate Cox regression analysis. RESULTS: Log-rank analysis found no statistically significant association between global graft survival and PDRI quartiles. Univariate Cox regression analysis showed a statistically significant association between graft survival and cold ischemia time (P < .05). CONCLUSIONS: PDRI was not a useful tool to predict pancreatic graft outcomes in a Spanish reference population.

Attractive interactions between like-charged colloidal particles at the air/water interface.

In the past few years, measurements of the pair interaction potential have shown evidence of micrometer-range attractive interactions between colloidal particles trapped between glass plates. In these experiments it is believed that the glass walls play an important role in the observed attractions. Colloidal particles trapped at the air/water interface show the formation of different 2-D colloidal patterns such as foams, clusters, and chains, whose formation has been taken as evidence of micrometer-range attractive interaction. Here, we present measurements of the pair interaction potential between 0.5-microm colloidal particles at the air/water interface. Indeed, the pair potential shows an attractive secondary minimum at about 1.9sigma, where sigma is the particle's diameter. Surprisingly, the position and depth of the secondary well are similar to those found in colloidal systems trapped between glass plates. However, we do not have a clear explanation on the origin of the attractive component of the interaction potential.