Advanced surface characterization of silver nanocluster segregation in Ag-TiCN bioactive coatings by RBS, GDOES, and ARXPS.

Surface modification by means of wear protective and antibacterial coatings represents, nowadays, a crucial challenge in the biomaterials field in order to enhance the lifetime of bio-devices. It is possible to tailor the properties of the material by using an appropriate combination of high wear resistance (e.g., nitride or carbide coatings) and biocide agents (e.g., noble metals as silver) to fulfill its final application. This behavior is controlled at last by the outmost surface of the coating. Therefore, the analytical characterization of these new materials requires high-resolution analytical techniques able to provide information about surface and depth composition down to the nanometric level. Among these techniques are Rutherford backscattering spectrometry (RBS), glow discharge optical emission spectroscopy (GDOES), and angle resolved X-ray photoelectron spectroscopy (ARXPS). In this work, we present a comparative RBS-GDOES-ARXPS study of the surface characterization of Ag-TiCN coatings with Ag/Ti atomic ratios varying from 0 to 1.49, deposited at room temperature and 200 °C. RBS analysis allowed a precise quantification of the silver content along the coating with a non-uniform Ag depth distribution for the samples with higher Ag content. GDOES surface profiling revealed that the samples with higher Ag content as well as the samples deposited at 200 °C showed an ultrathin (1-10 nm) Ag-rich layer on the coating surface followed by a silver depletion zone (20-30 nm), being the thickness of both layers enhanced with Ag content and deposition temperature. ARXPS analysis confirmed these observations after applying general algorithm involving regularization in addition to singular value decomposition techniques to obtain the concentration depth profiles. Finally, ARXPS measurements were used to provide further information on the surface morphology of the samples obtaining an excellent agreement with SEM observations when a growth model of silver islands with a height d = 1.5 nm and coverage θ = 0.20 was applied to the sample with Ag/Ti = 1.49 and deposited at room temperature.

Females without reflux symptoms or gastroesophageal reflux disease have less distal esophageal acid exposure than males without reflux symptoms or gastroesophageal reflux disease.

Ambulatory 24-hour esophageal pH monitoring is the gold standard examination to assess esophageal acid exposure. Gender-related variation is a well-recognized physiologic phenomenon in health and disease. To date, limited gender-specific 24-hour esophageal pH monitoring data are available. The aim of this study was to obtain values of esophageal pH monitoring in males and females without reflux symptoms or gastroesophageal reflux disease (GERD) to determine if gender variation exists in esophageal acid exposure among individuals without these factors. Twenty-four-hour dual esophageal pH monitoring was performed in male and female volunteers without reflux symptoms or GERD. Values for total number of reflux episodes, episodes longer than 5 minutes, total reflux time in minutes, % time with pH below 4, and longest reflux episode in the proximal/distal esophagus were obtained and recorded for both groups. The distal channel was placed 5 cm and proximal channel 15 cm above the manometrically determined lower esophageal sphincter. Means were compared using an independent sample t-test. Sixty-seven males and 69 females were enrolled. All subjects completed esophageal 24-hour pH monitoring without difficulty. There was no age or body mass difference between groups. Females had significantly fewer reflux episodes at both esophageal measuring sites and, significantly less total reflux time and % time with pH below 4 in the distal esophagus than males. All other parameters were similar. Significant gender-related differences exist in esophageal acid exposure, especially in the distal esophagus in individuals without reflux symptoms or GERD. These differences underscore the need for gender-specific reference values for 24-hour pH monitoring, allowing for an accurate evaluation of esophageal acid exposure in symptomatic patients.

Genome-wide linkage scan of bipolar disorder in a Colombian population isolate replicates Loci on chromosomes 7p21-22, 1p31, 16p12 and 21q21-22 and identifies a novel locus on chromosome 12q.

BACKGROUND/AIMS: Bipolar disorder (BP) is a severe psychiatric illness, characterised by alternating episodes of depression and mania, which ranks among the top ten causes of morbidity and life-long disability world-wide. We have previously performed a whole-genome linkage scan on 6 pedigrees segregating severe BP from the well-characterised population isolate of Antioquia, Colombia. We recently collected genotypes for the same set of 382 autosomal microsatellite markers in 9 additional Antioquian BP pedigrees. Here, we report the analysis of the combined pedigree set. METHODS: Linkage analysis using both parametric and nonparametric approaches was conducted for 3 different diagnostic models: severe BP only (BPI); mood disorders (BPI, BPII and major depression); and psychosis (operationally defined by the occurrence of at least 1 episode of hallucinations and/or delusions). RESULTS AND CONCLUSION: For BPI only, the most interesting result was obtained for chromosome 7p21.1-p22.2 under a recessive model of inheritance (heterogeneity LOD score = 2.80), a region that had previously been linked to BP in a study on Portuguese Island families. For both BPI and mood disorders, nonparametric analyses identified a locus on chromosome 12ct-q14 (nonparametric linkage = 2.55 and 2.35, respectively). This locus has not previously been reported as a candidate region for BP. Additional candidate regions were found on chromosomes 1p22-31 (mood disorders) and 21q21-22 (BPI), 2 loci that have repeatedly been implicated in BP susceptibility. Linkage analysis of psychosis as a phenotype identified candidate regions on chromosomes 2q24-31 and 16p12-q12. The finding on chromosome 16p is noteworthy because the same locus has been implicated by genome-wide association analyses of BP.

MC3T3-E1 cell response to microporous tantalum oxide surfaces enriched with Ca, P and Mg.

The formation of a porous oxide surface doped with osteoconductive elements, Ca, P and Mg, to enhance osseointegration, was achieved through micro arc oxidation. Micro arc oxidation parameters, such as electrolyte composition, concentration and applied voltage, were studied to understand their effect on the morphology and chemical composition of the samples surface. Considering the optimum atomic concentration reported in literature for each osteoconductive element, microporous Ta anodic oxide samples treated with calcium acetate (CaA) and ß-glycerophosphate (ß-GP) revealed that an increase of ß-GP molarity in the electrolyte boosts Ca incorporation, as well as, increasing the porosity. In adding magnesium acetate (MgA) to the electrolyte, when composed by CaA + ß-GP, both addition and variation of MgA did not affect the surface morphology along the samples, being incorporated into the oxide layer for 0.1 M. Finally, in vitro tests were carried out to study the biocompatibility of Ta, to verify the cytotoxicity of the samples and their behavior towards cells, by performing adhesion and differentiation tests with the MC3T3-E1 cell line. Cytotoxicity tests revealed that the samples were non-toxic. Despite none of the samples having been raised up through cell adhesion tests, cell differentiation revealed promising results for the Ta-CaP.

A narrow and highly significant linkage signal for severe bipolar disorder in the chromosome 5q33 region in Latin American pedigrees.

We previously reported linkage of bipolar disorder to 5q33-q34 in families from two closely related population isolates, the Central Valley of Costa Rica (CVCR) and Antioquia, Colombia (CO). Here we present follow up results from fine-scale mapping in large CVCR and CO families segregating severe bipolar disorder, BP-I, and in 343 population trios/duos from CVCR and CO. Employing densely spaced SNPs to fine map the prior linkage peak region increases linkage evidence and clarifies the position of the putative BP-I locus. We performed two-point linkage analysis with 1134 SNPs in an approximately 9 Mb region between markers D5S410 and D5S422. Combining pedigrees from CVCR and CO yields a LOD score of 4.9 at SNP rs10035961. Two other SNPs (rs7721142 and rs1422795) within the same 94 kb region also displayed LOD scores greater than 4. This linkage peak coincides with our prior microsatellite results and suggests a narrowed BP-I susceptibility regions in these families. To investigate if the locus implicated in the familial form of BP-I also contributes to disease risk in the population, we followed up the family results with association analysis in duo and trio samples, obtaining signals within 2 Mb of the peak linkage signal in the pedigrees; rs12523547 and rs267015 (P = 0.00004 and 0.00016, respectively) in the CO sample and rs244960 in the CVCR sample and the combined sample, with P = 0.00032 and 0.00016, respectively. It remains unclear whether these association results reflect the same locus contributing to BP susceptibility within the extended pedigrees.

A complementary role of multiparameter flow cytometry and high-throughput sequencing for minimal residual disease detection in chronic lymphocytic leukemia: an European Research Initiative on CLL study.

In chronic lymphocytic leukemia (CLL) the level of minimal residual disease (MRD) after therapy is an independent predictor of outcome. Given the increasing number of new agents being explored for CLL therapy, using MRD as a surrogate could greatly reduce the time necessary to assess their efficacy. In this European Research Initiative on CLL (ERIC) project we have identified and validated a flow-cytometric approach to reliably quantitate CLL cells to the level of 0.0010% (10(-5)). The assay comprises a core panel of six markers (i.e. CD19, CD20, CD5, CD43, CD79b and CD81) with a component specification independent of instrument and reagents, which can be locally re-validated using normal peripheral blood. This method is directly comparable to previous ERIC-designed assays and also provides a backbone for investigation of new markers. A parallel analysis of high-throughput sequencing using the ClonoSEQ assay showed good concordance with flow cytometry results at the 0.010% (10(-4)) level, the MRD threshold defined in the 2008 International Workshop on CLL guidelines, but it also provides good linearity to a detection limit of 1 in a million (10(-6)). The combination of both technologies would permit a highly sensitive approach to MRD detection while providing a reproducible and broadly accessible method to quantify residual disease and optimize treatment in CLL.

Silver activation on thin films of Ag-ZrCN coatings for antimicrobial activity.

Nowadays, with the increase of elderly population and related health problems, knee and hip joint prosthesis are being widely used worldwide. However, failure of these invasive devices occurs in a high percentage thus demanding the revision of the chirurgical procedure. Within the reasons of failure, microbial infections, either hospital or subsequently-acquired, contribute in high number to the statistics. Staphylococcus epidermidis (S. epidermidis) has emerged as one of the major nosocomial pathogens associated with these infections. Silver has a historic performance in medicine due to its potent antimicrobial activity, with a broad-spectrum on the activity of different types of microorganisms. Consequently, the main goal of this work was to produce Ag-ZrCN coatings with antimicrobial activity, for the surface modification of hip prostheses. Thin films of ZrCN with several silver concentrations were deposited onto stainless steel 316 L, by DC reactive magnetron sputtering, using two targets, Zr and Zr with silver pellets (Zr+Ag target), in an atmosphere containing Ar, C2H2 and N2. The antimicrobial activity of the modified surfaces was tested against S. epidermidis and the influence of an activation step of silver was assessed by testing samples after immersion in a 5% (w/v) NaClO solution for 5 min. The activation procedure revealed to be essential for the antimicrobial activity, as observed by the presence of an inhibition halo on the surface with 11 at.% of Ag. The morphology analysis of the surface before and after the activation procedure revealed differences in silver distribution indicating segregation/diffusion of the metallic element to the film's surface. Thus, the results indicate that the silver activation step is responsible for an antimicrobial effect of the coatings, due to silver oxidation and silver ion release.

Escherichia coli-induced temporal and differential secretion of heat-shock protein 70 and interleukin-1ß by human fetal membranes in a two-compartment culture system.

INTRODUCTION: Escherichia coli is recognized as an etiological bacteria associated with chorioamnionitis and the preterm premature rupture of fetal membranes. This pathological condition induces pro-inflammatory cytokines and degradative metalloproteinases, which are considered biological markers secreted in an acute stage of infection. Heat-shock proteins (HSPs) are an important component of the innate immunity response and are found in different pathological conditions. They have not been previously measured in human fetal membranes in response to infectious conditions. We hypothesized that the choriodecidual tissue and amniotic epithelium secreted temporal and differential Hsp-60, Hsp-70, and interleukin (IL)-1ß mediated by E. coli infection. METHODS: Fetal membranes were mounted in a two-compartment culture system and infected with two passes of live E. coli at different doses (10², 104, 105, and 106 colony-forming units (CFU)/mL) and intervals of incubation (3, 6, and 24 h). The culture medium was collected, and Hsp-60, Hsp-70, and IL-1ß were assessed using the enzyme-linked immunosorbent assay (ELISA) method. RESULTS: After 3 and 6 h of infection, E. coli induced an increase in Hsp-70 secretion in the choriodecidual tissue. However, after 24 h of incubation, Hsp-70 was downregulated and we observed an increase in IL-1ß secretion. By contrast, E. coli induced a lower Hsp-60 secretion in the amnion compared to Hsp-70. DISCUSSION: Human fetal membranes responded actively to E. coli infection, with an increase in Hsp-70 during the first hours of infection. After 24 h, there was an increase in the liberation of IL-1ß.

An association study of bipolar mood disorder (type I) with the 5-HTTLPR serotonin transporter polymorphism in a human population isolate from Colombia.

The short variant of a functional length polymorphism in the promoter region of the serotonin transporter has been associated with several behavioural and psychiatric traits, including bipolar mood disorder. The same short allele has also been implicated as a modifier of the bipolar phenotype. Here we evaluate the etiologic/modifier role of this polymorphism in a case (N=103) / control (N=112) sample for bipolar mood disorder (type I) collected from an isolated South American population. We did not detect an association between bipolar disorder and the 5-HTT promoter polymorphism in this sample. However, an excess of the short allele was seen in younger cases and in cases with psychotic symptoms. When combined with data from the literature, the increased frequency of the short allele in patients with psychotic symptoms was statistically significant.

[Thrombocytopenic thrombotic purpura. Retrospective study of 22 consecutive occurrences in 16 patients]. / Púrpura trombótica trombocitopénica. Estudio retrospectivo de 22 episodios consecutivos en 16 pacientes.

BACKGROUND: Thrombotic Thrombocytopenic Purpura (TTP) is an uncommon clinical syndrome with high mortality rate in the absence of treatment. Despite the therapeutic efficacy of plasma exchange, patients often relapse even after long periods of time in remission. Over the last few years, late relapses in previously diagnosed patients have been seen in our hospital. PATIENTS AND METHODS: We analyzed retrospectively 22 episodes of TTP in 16 patients diagnosed during a four-year period. We reviewed the clinical features at diagnosis as well as the therapeutic results. In all but one, the treatment included daily plasma exchange. Other treatments, including vincristine, were also used in addition to plasma exchange, in 18 of 21 episodes. RESULTS: A complete remission was obtained in eighty-two percent of the episodes treated by plasma exchange. The median number of plasma exchange to achieve a complete remission was 6. In 4 episodes, 20 or more plasma exchange were required before achieving a satisfactory response. A complete remission was obtained in 78% of episodes where vincristine was used, versus 84% response rate in episodes where vincristine was not used. In four patients the cause death was directly related to TTP, while a fifth patients died of progressive lymphoma without evidence of TTP. Five of the eleven surviving patients relapsed with a median time to relapse of 24.6 months. Relapsing episodes presented with a less severe clinical picture including less clear signs of microangiopathic hemolytic anemia (MAHA), when compared with the initial ones. All patients in relapse responded promptly to treatment. The variables analyzed failed to predict either the response to treatment or the probability of relapse. CONCLUSIONS: The therapeutic efficacy of plasma exchange in the treatment of TTP has been demonstrated in our series as previously observed by many other groups. We have observed some slow responders where the prolongation of treatment by plasma exchange succeeded in achieving a complete remission. The use of vincristine did not show any therapeutical advantage in our experience.

Targeting the proliferative and chemoresistant compartment in chronic lymphocytic leukemia by inhibiting survivin protein.

Chronic lymphocytic leukemia (CLL) cells located in proliferation centers are constantly stimulated by accessory cells, which provide them with survival and proliferative signals and mediate chemotherapy resistance. Herein, we designed an experimental strategy with the aim of mimicking the microenvironment found in the proliferative centers to specifically target actively proliferating CLL cells. For this, we co-cultured CLL cells and bone marrow stromal cells with concomitant CD40 and Toll-like receptor 9 stimulation. This co-culture system induced proliferation, cell-cycle entry and marked resistance to treatment with fludarabine and bendamustine. Proliferating CLL cells clustered together showed a typical morphology of activated B cells and expressed survivin protein, a member of the inhibitor of apoptosis family that is mainly expressed by CLL cells in the proliferation centers. With the aim of specifically targeting actively proliferating and chemoresistant CLL cells, we investigated the effects of treatment with YM155, a small-molecule survivin inhibitor. YM155 treatment suppressed the co-culture-induced survivin expression and that was sufficient to inhibit proliferation and effectively induce apoptosis particularly in the proliferative subset of CLL cells. Interestingly, sensitivity to YM155 was independent from common prognostic markers, including 17p13.1 deletion. Altogether, these findings provide a rationale for clinical development of YM155 in CLL.

Incidence of hypoglycemia with tight glycemic control protocols: a comparative study.

BACKGROUND: Comparison of hypoglycemia incidence among tight glycemic control (TGC) protocols is a crucial aspect that has not been done in previous trials. This study compared the incidence of hypoglycemia using three TGC protocols in critically ill patients. METHODOLOGY: This was a prospective study of 420 patients over 18 months. Patients were divided into three groups by TGC protocol: A (modified Leuven protocol), B (Georgia Hospital Association protocol, target blood glucose [BG] 80-110 mg/dL), and C (modified Georgia Hospital Association protocol, target BG 90-140 mg/dL). End points included differences in the incidence of first-degree hypoglycemia (BG or= 180 mg/dL). RESULTS: A total of 34,497 BG samples were analyzed: group A, 11,202 (32.47%); group B, 9,627 (27.91%); and group C, 13,668 (39.62%). First-degree hypoglycemia was more frequent in group A (348 episodes [3.11%]) compared to group B (209 episodes [2.17%] [odds ratio (OR) 1.45, 95% confidence interval (CI) 1.25-1.172, P = 0.001]) and group C (266 episodes [1.95%] [OR 1.66, 95% CI 1.37-1.89, P = 0.001]). Second-degree hypoglycemia was more frequent in group A (131 episodes [1.17%]) compared to group B (62 episodes [0.64%] [OR 1.83, 95% CI 1.22-1.72, P = 0.001]) and group C (58 episodes [0.42%] [OR 2.77, 95% CI 2.04-3.79, P = 0.001]). No significant difference was found when groups B and C were compared (P = 0.10 and P = 0.06, respectively). Hyperglycemia was significantly more common in group A (2,175 episodes [19.42%]) compared to group B (1,333 episodes [13.83%] [OR 1.49, 95% CI 1.39-1.62, P = 0.001], but there was no significant difference compared to group C (2,560 episodes [18.73%] [P = 0.17]). CONCLUSIONS: TGC protocols vary in their risk of inducing hypoglycemia. Whether this translates into differences in clinical outcomes such as mortality and adverse effects is still to be determined by future studies.

Influence of surface hydroxylation on 3-aminopropyltriethoxysilane growth mode during chemical functionalization of GaN Surfaces: an angle-resolved X-ray photoelectron spectroscopy Study.

A comparative study of the chemical functionalization of undoped, n- and p-type GaN layers grown on sapphire substrates by metal-organic chemical vapor deposition was carried out. Both types of samples were chemically functionalized with 3-aminopropyltriethoxysilane (APTES) using a well-established silane-based approach for functionalizing hydroxylated surfaces. The untreated surfaces as well as those modified by hydroxylation and APTES deposition were analyzed using angle-resolved X-ray photoelectron spectroscopy. Strong differences were found between the APTES growth modes on n- and p-GaN surfaces that can be associated with the number of available hydroxyl groups on the GaN surface of each sample. Depending on the density of surface hydroxyl groups, different mechanisms of APTES attachment to the GaN surface take place in such a way that the APTES growth mode changes from a monolayer to a multilayer growth mode when the number of surface hydroxyl groups is decreased. Specifically, a monolayer growth mode with a surface coverage of approximately 78% was found on p-GaN, whereas the formation of a dense film, approximately 3 monolayers thick, was observed on n-GaN.

[Remission of invasive sinusal and pulmonary aspergillosis with liposomal amphotericin B in a patient with chronic lymphatic leukemia following failure with conventional amphotericin]. / Resolución de una aspergilosis invasiva sinusal y pulmonar con anfotericina B liposómica en un paciente con leucemia linfática crónica tras fracaso de la anfotericina convencional.

Invasive aspergillosis is a severe complication in the immunocompromised patient. Despite antifungal treatment the mortality rate is higher than 90% if the immunity deficiency is not corrected. The use and dosage of conventional amphotericin B (deoxycholate-suspended formulation) is limited by its toxicity, especially nephrotoxicity. To reduce these untoward effects, amphotericin B has been formulated in liposomes. Better tolerance and lower nephrotoxicity in the liposomal formulations allow higher doses to be given safely, even in the presence of renal failure. Liposomal encapsulated amphotericin B (LAmB) is a safe and effective alternative to conventional formulations for antifungal therapy. We present a case of a 60-year-old man affected by chronic lymphocytic leukaemia. In the course of his disease and after chemotherapy treatment, he presented an invasive aspergillosis of the lung and paransal sinuses. The rhino-sinusal lesion had progressed despite surgical debridement and treatment with amphotericin B in a dosage of 50 mg per day. Moreover, renal impairment caused by conventional amphotericin was detected. Then, LAmB was started at a dose of 150 mg per day. Treatment with LAmB has resulted in clinical recovery and radiologic ressolution.

Flow cytometry in the bone marrow evaluation of follicular and diffuse large B-cell lymphomas.

BACKGROUND AND OBJECTIVES: Bone marrow biopsies are routinely performed in the staging of patients with lymphoma. Despite the lack of evidence for its usefulness, many institutions include flow cytometry (FC) of bone-marrow aspirates in an attempt to increase sensitivity and specificity. The aim of this study is to evaluate the usefulness of FC for the assessment of bone-marrow involvement by lymphoma in follicular (FL) and diffuse large B-cell lymphomas (DLBCL). DESIGN AND METHODS: Seventy-nine bone marrow biopsies from 65 patients diagnosed with FL or DLBCL were examined to compare histology and FC for the assessment of bone-marrow involvement by lymphoma. RESULTS: Bone marrow histology showed involvement (BM+) in 16 cases (20.3%), lack of infiltration (BM(-)) in 52 cases (65.8%) and undetermined or undiagnosed for involvement (BMu) in 11 cases (13.9%). FC was positive for involvement in 28 cases (35.4%) and negative in 51 cases (64.6%). 65 cases (95%) showed concordance between the results of morphology and FC (BM(+)/FC(+) or BM(-)/FC(-)). No BM(+)/FC(-) cases were observed. 3 cases showed discrepant results (BM(-)/FC(+)). In these 3 cases the molecular studies (PCR) demonstrated clonal rearrangement of the heavy immunoglobulin chain (IgH) and/or bcl2-IgH in agreement with the flow results. Among the 11 cases with BMu, all but 2 were FC(+) and concordance with the PCR results was seen in 9 cases (81.9%). INTERPRETATION AND CONCLUSIONS: We conclude that FC is just as sensitive or perhaps slightly more sensitive than histology in the detection of bone marrow involvement in FL and DLBCL. FC studies may be warranted in those cases in which the morphology is not diagnosed. The clinical relevance of the small clonal B-cell population in patients without histologic bone marrow involvement (BM(-)/FC(+) cases) remains an open question.