Frucooligosaccharides purification: Complexing simple sugars with phenylboronic acid.

Prebiotic fructooligosaccharides (FOS) are currently obtained by enzymatic reaction with fructosyltransferases (FTFs) using sucrose as both donor and acceptor. In these reactions glucose results as the most abundant by-product, arising from each fructosyl transfer event and, together with fructose, because of the inherent hydrolytic activity of the FTFs. As FOS are mainly used as prebiotic in nutraceutical foods, the reduction or total elimination of monosaccharides is required. In this work the selective elimination of monosaccharides from a synthetic FOS mixture was achieved through the selective complexation of glucose and fructose with phenyl boronic acid (PBAc) followed by ethyl-acetate extraction. The process was applied to a complex mixture of FOS obtained in an enzymatic synthesis reaction containing 40% glucose, 15.8% fructose and 35% of FOS, elimination of the sugars was achieved through 3:1 molar reactions, resulting in a levan-type FOS product with 97% purity.

Barriers and Explanatory Mechanisms of Delays in the Patient and Diagnosis Intervals of Care for Breast Cancer in Mexico.

BACKGROUND: Most breast cancer patients in low- and middle-income settings are diagnosed at advanced stages due to lengthy intervals of care. This study aimed to understand the mechanisms through which delays occur in the patient interval and diagnosis interval of care. MATERIALS AND METHODS: We conducted a cross-sectional survey including 886 patients referred to four major public cancer hospitals in Mexico City. Based in a conceptual model of help-seeking behavior, a path analysis strategy was used to identify the relationships between explanatory factors of patient delay and diagnosis delay. RESULTS: The patient and the diagnosis intervals were greater than 3 months in 20% and 65% of participants, respectively. We present explanatory models for each interval and the interrelationship between the associated factors. The patient interval was longer among women who were single, interpreted their symptoms as not worrisome, concealed symptoms, and perceived a lack of financial resources and the difficulty of missing a day of work as barriers to seek care. These barriers were more commonly perceived among patients who were younger, had lower socioeconomic status, and lived outside of Mexico City. The diagnosis interval was longer among those who used several different health services prior to the cancer hospital and perceived medical errors in these services. More health services were used among those who perceived errors and long waiting times for appointments, and who first consulted private services. CONCLUSION: Our findings support the relevance of strengthening early cancer diagnosis strategies, especially the improvement of quality of primary care and expedited referral routes to cancer services. IMPLICATIONS FOR PRACTICE: This study's findings suggest that policy in low- and middle-income countries (LMICs) should be directed toward reducing delays in diagnosis, before the implementation of mammography screening programs. The results suggest several factors susceptible to early diagnosis interventions. To reduce patient delays, the usually proposed intervention of awareness promotion could better work in LMIC contexts if the message goes beyond the advertising of screening mammography to encourage the recognition of potential cancer symptoms and sharing of symptoms with significant others. To reduce diagnosis delay, efforts should focus on strengthening the quality of public primary care services and improving referral routes to cancer care centers.

Emergence of Plasmid-Borne dfrA14 Trimethoprim Resistance Gene in Shigella sonnei.

The most common mechanism of trimethoprim (TMP)-resistance is the acquisition of dihydrofolate reductase enzyme resistant to this drug. Previous molecular characterization of TMP-genes resistance in Chilean isolates of Shigella sonnei searching for dfrA1 and dfrA8, showed solely the presence of dfrA8 (formerly dhfrIIIc). However, these genetic markers were absent in S. sonnei strains further isolated during an outbreak in 2009. To identify the TMP-resistance gene in these strains, a genomic DNA library from a TMP-resistant (TMP(R)) S. sonnei representative strain for the outbreak was used to clone, select and identify a TMP-resistance marker. The TMP(R) clone was sequenced by primer walking, identifying the presence of the dfrA14 gene in the sul2-strA'-dfrA14-'strA-strB gene arrangement, harbored in a native 6779-bp plasmid. The same plasmid was isolated by transforming with a ~4.2 MDa plasmid extracted from several TMP(R) S. sonnei strains into Escherichia coli. This plasmid, named pABC-3, was present only in dfrA14-positive strains and was homologous to a previously described pCERC-1, but different due to the absence of an 11-bp repetitive unit. The distribution of dfrA1, dfrA8, and dfrA14 TMP-resistance genes was determined in 126 TMP(R) S. sonnei isolates. Most of the strains (96%) carried only one of the three TMP-resistance genes assessed. Thus, all strains obtained during the 2009-outbreak harbored only dfrA14, whereas, dfrA8 was the most abundant gene marker before outbreak and, after the outbreak dfrA1 seems have appeared in circulating strains. According to PFGE, dfrA14-positive strains were clustered in a genetically related group including some dfrA1- and dfrA8-positive strains; meanwhile other genetic group included most of the dfrA8-positive strains. This distribution also correlated with the isolation period, showing a dynamics of trimethoprim genetic markers prevalent in Chilean S. sonnei strains. To our knowledge, dfrA14 gene associated to a small non-conjugative plasmid was detected for the first time in Shigella. Apparently, the strain causing the outbreak must have been introduced, changing drastically the genetic distribution of trimethoprim resistance in Chilean S. sonnei strains.

Molecular mechanisms of gastrointestinal protection by quercetin against indomethacin-induced damage: role of NF-κB and Nrf2.

The aim of this study was to determine the gastrointestinal protection by quercetin against indomethacin-induced oxidative stress and inflammation, with specific interest in studying the underlying molecular mechanisms. We hypothesized that the quercetin-protective effect relies on its antioxidant and antiinflammatory properties. Rats were pretreated with quercetin (50- or 100-mg/kg, ig single dose), 30 min before INDO administration (40-mg/kg ig single dose). Caco-2 cells were treated with INDO (250 and 500 µM) in the absence or presence of quercetin (10 µg/ml). Quercetin prevented the decrease in nuclear translocation of Nrf2, a key regulator of the antioxidant response, and the increase in reactive oxygen species levels induced by INDO by inhibiting the enhancement of NADPH oxidase and xanthine oxidase activities as well as the reduction in superoxide dismutase and glutathione peroxidase activities in gastric and ileal tissues. Quercetin also prevented INDO-induced ICAM-1 and P-selectin expressions and the increase of myeloperoxidase activity in gastric and ileal tissues and NF-κB activation and IL-8 production in Caco-2 cells. Quercetin did not affect the inhibition of TNFα-mediated production of prostaglandin E2 induced by INDO in Caco-2 cells. The protective effects of quercetin observed in the gastric and ileal mucosa of rats as well as in Caco-2 cells relied on the ability of this flavonol to prevent NF-κB activation and increase Nrf2 translocation. This study supports the concept that quercetin may be useful in the prevention and/or treatment of nonsteroidal antiinflammatory drug-associated side effects, without interfering with their therapeutic efficacy.

Health system delay and its effect on clinical stage of breast cancer: Multicenter study.

BACKGROUND: The objective of this study was to determine the correlation between health system delay and clinical disease stage in patients with breast cancer. METHODS: This was a cross-sectional study of 886 patients who were referred to 4 of the largest public cancer hospitals in Mexico City for the evaluation of a probable breast cancer. Data on time intervals, sociodemographic factors, and clinical stage at diagnosis were retrieved. A logistic regression model was used to estimate the average marginal effects of delay on the probability of being diagnosed with advanced breast cancer (stages III and IV). RESULTS: The median time between problem identification and the beginning of treatment was 7 months. The subinterval with the largest delay was that between the first medical consultation and diagnosis (median, 4 months). Only 15% of the patients who had cancer were diagnosed with stage 0 and I disease, and 48% were diagnosed with stage III and IV disease. Multivariate analyses confirmed independent correlations for the means of problem identification, patient delay, health system delay, and age with a higher probability that patients would begin cancer treatment in an advanced stage. CONCLUSIONS: In the sample studied, the majority of patients with breast cancer began treatment after a delay. Both patient delays and provider delays were associated with advanced disease. Research aimed at identifying specific access barriers to medical services is much needed to guide the design of tailored health policies that go beyond the promotion of breast care awareness and screening participation to include improvements in health services that facilitate access to timely diagnosis and treatment.

Heterogeneity in patient-reported outcomes following low-intensity mental health interventions: a multilevel analysis.

BACKGROUND: Variability in patient-reported outcomes of psychological treatments has been partly attributed to therapists--a phenomenon commonly known as therapist effects. Meta-analytic reviews reveal wide variation in therapist-attributable variability in psychotherapy outcomes, with most studies reporting therapist effects in the region of 5% to 10% and some finding minimal to no therapist effects. However, all except one study to date have been conducted in high-intensity or mixed intervention groups; therefore, there is scarcity of evidence on therapist effects in brief low-intensity psychological interventions. OBJECTIVE: To examine therapist effects in low-intensity interventions for depression and anxiety in a naturalistic setting. DATA AND ANALYSIS: Session-by-session data on patient-reported outcome measures were available for a cohort of 1,376 primary care psychotherapy patients treated by 38 therapists. Outcome measures included PHQ-9 (sensitive to depression) and GAD-7 (sensitive to general anxiety disorder) measures. Three-level hierarchical linear modelling was employed to estimate therapist-attributable proportion of variance in clinical outcomes. Therapist effects were evaluated using the intra-cluster correlation coefficient (ICC) and Bayesian empirical predictions of therapist random effects. Three sensitivity analyses were conducted: 1) using both treatment completers and non-completers; 2) a sub-sample of cases with baseline scores above the conventional clinical thresholds for PHQ-9 and GAD-7; and 3) a two-level model (using patient-level pre- and post-treatment scores nested within therapists). RESULTS: The ICC estimates for all outcome measures were very small, ranging between 0% and 1.3%, although most were statistically significant. The Bayesian empirical predictions showed that therapist random effects were not statistically significantly different from each other. Between patient variability explained most of the variance in outcomes. CONCLUSION: Consistent with the only other study to date in low intensity interventions, evidence was found to suggest minimal to no therapist effects in patient-reported outcomes. This draws attention to the more prominent source of variability which is found at the between-patient level.

Endogenous treatment effects for count data models with endogenous participation or sample selection.

In this paper, we propose an estimator for models in which an endogenous dichotomous treatment affects a count outcome in the presence of either sample selection or endogenous participation using maximum simulated likelihood. We allow for the treatment to have an effect on the participation or the sample selection rule and on the main outcome. Applications of this model are frequent in-but no limited to-health economics. We show an application of the model using data from Kenkel and Terza (2001), who investigate the effect of physician advice on the amount of alcohol consumption. Our estimates suggest that in these data (i) neglecting treatment endogeneity leads to a wrongly signed effect of physician advice on drinking intensity, (ii) accounting for treatment endogeneity but neglecting endogenous participation leads to an upward biased estimate of the treatment effect and (iii) advice affects only the drinking intensive margin but not drinking prevalence.

Non-pecuniary returns to higher education: the effect on smoking intensity in the UK.

This paper investigates whether higher education (HE) produces non-pecuniary returns via a reduction in the intensity of consumption of health-damaging substances. In particular, it focuses on current smoking intensity of the British individuals sampled in the 29-year follow-up survey of the 1970 British Cohort Study. We estimate endogenous dummy ordinal response models for cigarette consumption and show that HE is endogenous with respect to smoking intensity and that even when endogeneity is accounted for, HE is found to have a strong negative effect on smoking intensity. Moreover, pecuniary channels, such as occupation and income, mediate only a minor part of the effect of HE. Our results are robust to modelling individual self-selection into current smoking participation (at age 29) and to estimating a dynamic model in which past smoking levels affect current smoking levels.

[Morphology and cytochemistry of Aedes aegypti's cell cultures (Diptera: Culicidae) and susceptibility to Leishmania panamensis (Kinetoplastida: Trypanosomatidae)]. / Morfología y citoquímica de cultivos celulares de Aedes aegypti (Diptera: Culicidae) y susceptibilidad a Leishmania panamensis (Kinetoplastida: Trypanosomatidae).

Morphology and cytochemistry of Aedes aegypti's cell cultures (Diptera: Culicidae) and susceptibility to Leishmania panamensis (Kinetoplastida: Trypanosomatidae). The first cellular line of Aedes aegypti was developed by Grace in 1966; afterwards, other cellular lines of this species have been generated. These have been used for the study of pathogenic organisms like viruses, bacteria and parasites, which demonstrates their importance in biomedical applications. This research describes, for the first time, some cytochemical characteristics of A. aegypti cell cultures, that were infected with (MHOM/CO/87CL412) strain of Leishmania panamensis. A morphological study of the cell culture was also carried out. Maintenance of the cell culture, parasites and infection in vitro were carried out in the Laboratory of Entomology, Cell Biology and Genetics of the Universidad de La Salle. The cell cultures infected with the parasite were maintained in a mixture of mediums Grace/L15, supplemented with 10 % fetal bovine serum (FBS) at pH 6.8 and a temperature of 26 degrees C, during 3, 6 and 9 post-infection days. After this, these cell cultures were processed through High Resolution Light Microscopy (HRLM) and Transmission Electron Microscopy (TEM) based on standard protocols defined by the Group of Microscopy and Image Analyses of the Instituto Nacional de Salud. Semi-fine slices of 1 microm colored with toluidine blue were used for the morphological analysis of the culture, and ultra fine cuts of 60 to 90 nm stained with uranyl acetate and lead citrate where used for the ultrastructural study. In addition, PAS and peroxidase staining was carried out in cells fixed with methanol. The morphometric study was analyzed with software ImageJ (NIH). In the semi-fine slices, small cells were observed showing fibroblastic appearance 10.84 +/- 2.54 microm in length and 5.31 +/- 1.26 microm wide; other cells had epithelial appearance with a great peripheral nucleus, voluminous and vacuolated cytoplasm, 23.04 +/- 4.00 microm in length and 13.96 3.70 microm wide. These last ones predominated over the ones with fibroblastic appearance. Regarding the PAS coloration, 7.08% of the cells presented abundant PAS positive cytoplasmatic granules which indicated polysaccharides presence. The peroxidase test gave a negative result. The greatest percentage of infection (18.90%) of one total of 101 cells, turned up by day 6. Some cells analyzed by TEM presented a vacuolated aspect cytoplasm; some contained parasites, other fibrillar material and others were empty. The results indicate that A. aegypti cell culture can support the internalization and transformation of the parasite, which demonstrates the capacity that these cell cultures have to be infected with L. panamensis and to maintain the infection for approximately one week.

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