Hydrodynamic cavitation-assisted acid pretreatment and fed-batch simultaneous saccharification and co-fermentation for ethanol production from sugarcane bagasse using immobilized cells of Scheffersomyces parashehatae

A new alternative for hydrodynamic cavitation-assisted pretreatment of sugarcane bagasse was proposed, along with a simultaneous saccharification and co-fermentation (SSCF) process performed in interconnected columns. Influential variables in the pretreatment were evaluated using a statistical design, indicating that an ozone flow rate of 10 mg min-1 and a pH of 5.10 resulted in 86 % and 72 % glucan and xylan hydrolysis yields, respectively, in the subsequent enzymatic hydrolysis process. Under these optimized conditions, iron sulfate (15 mg L-1) was added to assess Fenton pretreatment, resulting in glucan and xylan hydrolysis yields of 92 % and 71 %, respectively, in a material pretreated for 10 min. In SSCF, ethanol volumetric productivities of 0.33 g L-1 h-1 and of 0.54 g L-1 h-1 were obtained in batch and fed-batch operation modes, achieving 26 g L-1 of ethanol in 48 h in the latter mode.

Exportin 1-mediated nuclear/cytoplasmic trafficking controls drug sensitivity of classical Hodgkin's lymphoma

Exportin 1 (XPO1) is the main nuclear export receptor that controls the subcellular trafficking and the functions of major regulatory proteins. XPO1 is overexpressed in various cancers and small inhibitors of nuclear export (SINEs) have been developed to inhibit XPO1. In primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin's lymphoma (cHL), the XPO1 gene may be mutated on one nucleotide and encodes the mutant XPO1E571K . To understand the impact of mutation on protein function, we studied the response of PMBL and cHL cells to selinexor, a SINE, and ibrutinib, an inhibitor of Bruton tyrosine kinase. XPO1 mutation renders lymphoma cells more sensitive to selinexor due to a faster degradation of mutant XPO1 compared to the wild-type. We further showed that a mistrafficking of p65 (RELA) and p52 (NFκB2) transcription factors between the nuclear and cytoplasmic compartments accounts for the response toward ibrutinib. XPO1 mutation may be envisaged as a biomarker of the response of PMBL and cHL cells and other B-cell hemopathies to SINEs and drugs that target even indirectly the NFκB signaling pathway.

Physical and chemical characterization of drill cuttings: A review

Drill cuttings comprise a mixture of rocks generated during drilling activities of exploration and production of oil and gas. These residues' properties are variable, depending on several drilling parameters and drilled rock composition. Many scientific studies have been published regarding the characterization of these residues. Articles summarizing these residues' characteristics and toxicity data are poorly explored in the literature. This work reviews the principal methods used to characterize drill cuttings and data about these residues' properties. Some authors have reported the large content of Zn in drill cuttings. These cuttings can be associated with base fluids (as olefins, varying from C11 to C18), and some time crude oil (high range of TPH, unresolved complex mixtures, and PAH compounds). Acute and chronic toxicity tests have shown negative impacts of different types of fluids, the components of these fluids, and cuttings on other marine organisms.

C/EBPα Confers Dependence to Fatty Acid Anabolic Pathways and Vulnerability to Lipid Oxidative Stress-Induced Ferroptosis in FLT3-Mutant Leukemia

Although transcription factor CCAAT-enhancer binding protein α (C/EBPα) is critical for normal and leukemic differentiation, its role in cell and metabolic homeostasis is largely unknown in cancer. Here, multiomics analyses uncovered a coordinated activation of C/EBPα and Fms-like tyrosine kinase 3 (FLT3) that increased lipid anabolism in vivo and in patients with FLT3-mutant acute myeloid leukemia (AML). Mechanistically, C/EBPα regulated the fatty acid synthase (FASN)-stearoyl-CoA desaturase (SCD) axis to promote fatty acid (FA) biosynthesis and desaturation. We further demonstrated that FLT3 or C/EBPα inactivation decreased monounsaturated FA incorporation to membrane phospholipids through SCD downregulation. Consequently, SCD inhibition enhanced susceptibility to lipid redox stress that was exploited by combining FLT3 and glutathione peroxidase 4 inhibition to trigger lipid oxidative stress, enhancing ferroptotic death of FLT3-mutant AML cells. Altogether, our study reveals a C/EBPα function in lipid homeostasis and adaptation to redox stress, and a previously unreported vulnerability of FLT3-mutant AML to ferroptosis with promising therapeutic application.

SIGNIFICANCE

FLT3 mutations are found in 30% of AML cases and are actionable by tyrosine kinase inhibitors. Here, we discovered that C/EBPα regulates FA biosynthesis and protection from lipid redox stress downstream mutant-FLT3 signaling, which confers a vulnerability to ferroptosis upon FLT3 inhibition with therapeutic potential in AML. This article is highlighted in the In This Issue feature, p. 1501.

The role of microglia in 67NR mammary tumor-induced suppression of brain responses to immune challenges in female mice

It is poorly understood how solid peripheral tumors affect brain neuroimmune responses despite the various brain-mediated side effects and higher rates of infection reported in cancer patients. We hypothesized that chronic low-grade peripheral tumor-induced inflammation conditions microglia to drive suppression of neuroinflammatory responses to a subsequent peripheral immune challenge. Here, Balb/c murine mammary tumors attenuated the microglial inflammatory gene expression responses to lipopolysaccharide (LPS) and live Escherichia coli (E. coli) challenges and the fatigue response to an E. coli infection. In contrast, the inflammatory gene expression in response to LPS or a toll-like receptor 2 agonist of Percoll-enriched primary microglia cultures was comparable between tumor-bearing and -free mice, as were the neuroinflammatory and sickness behavioral responses to an intracerebroventricular interleukin (IL)-1β injection. These data led to the hypothesis that Balb/c mammary tumors blunt the neuroinflammatory responses to an immune challenge via a mechanism involving tumor suppression of the peripheral humoral response. Balb/c mammary tumors modestly attenuated select circulating cytokine responses to LPS and E. coli challenges. Further, a second mammary tumor/mouse strain model (E0771 tumors in C57Bl/6 mice) displayed mildly elevated inflammatory responses to an immune challenge. Taken together, these data indicate that tumor-induced suppression of neuroinflammation and sickness behaviors may be driven by a blunted microglial phenotype, partly because of an attenuated peripheral signal to the brain, which may contribute to infection responses and behavioral side effects reported in cancer patients. Finally, these neuroimmune effects likely vary based on tumor type and/or host immune phenotype.

Non-ionic surfactant formulation sequentially enhances the enzymatic hydrolysis of cellulignin from sugarcane bagasse and the production of Monascus ruber biopigments

The effect of a non-ionic surfactant optimized formulation (SOF) obtained from an experimental design was evaluated for different influencing variables in the processing of sugarcane bagasse cellulignin to produce biopigments. The major findings in the saccharification stage using the SOF point that: at same enzyme loading, the highest glucan hydrolysis yield was 63 % (2-fold higher compared to control); the enzyme loading of 2.5 FPU/g resulted in similar yield compared to 10 FPU/g (control); 15 % (m/v) of total solids loading maintained the yield in fed-batch configuration; the hydrolysis yield is maintained at high shear force stress (800 rpm of stirring rate) and temperatures (50-70 °C). Besides, under separate and semi-simultaneous hydrolysis and fermentation, the maximum biopigments production were of 10 AU_510nm/mL and 17.84 AU_510nm/mL, respectively. The SOF used in this study was found to be a promising additive either in a single or sequential steps to produce biopigments in biorefineries.

Abstract 847: Role of RHOA in diffuse gastric cancer tumors

Gastric cancer constitutes the third leading cause of cancer mortality worldwide and tumors with diffuse histology have poor prognosis and low response rates to therapy. Missense mutations in the RHOA (Ras homolog family member A) GTPase have recently been identified in 24% of patients with diffuse gastric cancer. RHOA mutations are not randomly distributed along the coding sequence, but enriched in specific and recurrent hotspots. Substitution in codon 42 (Y42C) occurs in approximately 50% of the patients in which RHOA is mutated. RHOA orchestrates cellular processes such as proliferation, differentiation, migration and invasion, whose deregulation is essential for the onset, maintenance and progression of tumors. However, the functional role of wild type RHOA and RHOA mutants remains poorly characterized in gastric cancer. We used isogenic cell lines systems and animal models to study the impact of RHOA in the gastric tumorigenesis. RHOA loss strongly increased the proliferation, migration and invasion of diffuse gastric cancer cells in vitro, but also when growing as subcutaneous xenografts in immunodeficient mice, and in experimental mouse models of peritoneal and lung metastasis. Stomach tumor burden was also increased in transgenic mice conditionally expressing a dominant negative form of RHOA in the gastrointestinal tract (RHOA T19N). Moreover, cells overexpressing wild-type RHOA or G14V RHOA (a constitutive active form of the GTPase) exhibited reduced tumorigenic features both in vitro and in vivo. Conversely, diffuse gastric cancer cells engineered for overexpressing RHOA Y42C mutant, displayed enhanced growth and invasion in vitro. Importantly, stomach cancer tumors formed more efficiently in a transgenic mouse model in which we targeted the expression of Y42C RHOA mutant to the gastric epithelium. Collectively, these results demonstrate that RHOA has tumor-suppressive activity in diffuse gastric cancer, while the recurrent Y42C hotspot RHOA mutation found in these tumors is oncogenic.

Citation Format: Agueda Martinez-Barriocanal, Higinio Dopeso, Lizbeth M. Jiménez-Flores, Juliana C. Santos, Estefania Anguita, Josipa Bilic, Rocio Nieto, Elia García-Vidal, Manuel Sánchez Martín, Stefania Landolfi, Kazuto Kobayashi, Javier Hernandez-Losa, Simo Schwartz, Santiago Ramón y Cajal, Diego Arango. Role of RHOA in diffuse gastric cancer tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 847.

Abstract 2981: Loss of the small GTPase RHOA enhances lymphomagenesis and impairs the activity of lenalidomide in mantle cell lymphoma

The small GTPase Ras homolog family member A (RHOA) is one of the most extensively investigated members of the Rho GTPase family, that acts as a molecular switch controlling a wide variety of signal transduction pathways. Although RHOA has long been implicated in malignant transformation in solid tumors, recent evidences have demonstrated its tumor suppressor activity in different subgroups of B-cell non-Hodgkin lymphoma (B-NHL). Here, using a panel of 11 cell lines covering the most common and/or aggressive B-NHL subtypes, we observed that the lowest mRNA and protein levels of RHOA are found in mantle cell lymphoma (MCL), the most aggressive entity with a median overall survival of 5-7 years. Depletion of RHOA expression and activity was carried out in the two RHOA+ MCL cell lines, REC-1 and Z-138, by CRISPR/Cas9-mediated gene edition followed by RHOA pulldown activation assay. In RHOA knockout (KO) subclones, cell proliferation was increased by 40%, in association with a 10-fold increase in mitotic index and a 3-fold potentiation of cell migration, as assessed respectively by CellTitter-Glo assay, histone H3-pSer10 labeling and Transwell assay, thus suggesting a tumor suppressor role of RHOA in MCL malignancy. Comparative RNA-seq analysis of RHOAWT and RHOAKO MCL subclones then highlighted a crucial role of RHOA and its downstream signaling in the control of MCL cell proliferation, cell cycle and cell migration. Interestingly, the immunomodulatory drug lenalidomide has previously shown to regulate such processes and to be clinically active in patients with relapsed/refractory MCL. In a co-culture system associating RHOAWT MCL cells with peripheral blood-derived effector cells, we observed that lenalidomide treatment facilitated the formation of immunological synapse, as revealed by simultaneous immunodetection of effector T cells, target B cells and perforin, and by quantification of lactate dehydrogenase (LDH) release. Conversely, lenalidomide exhibited minimal effect in the RHOAKO MCL co-cultures, as shown by a 30-40% decrease in the formation of immune synapse and a 4-fold decrease in LDH secretion. Taken together, these data provide the first insight into the tumor suppressive activity of RHOA in MCL and into its requirement for the immune-mediated mechanism of action of lenalidomide in this disease. Ongoing in vivo validation studies will be presented.

Citation Format: Juliana C. Santos, Marcelo L. Ribeiro, Gael Roue. Loss of the small GTPase RHOA enhances lymphomagenesis and impairs the activity of lenalidomide in mantle cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2981.

A review on recent developments in hydrodynamic cavitation and advanced oxidative processes for pretreatment of lignocellulosic materials

Environmental problems due to utilization of fossil-derived materials for energy and chemical generation has prompted the use of renewable alternative sources, such as lignocellulose biomass (LB). Indeed, the production of biomolecules and biofuels from LB is among the most important current research topics aiming to development a sustainable bioeconomy. Yet, the industrial use of LB is limited by the recalcitrance of biomass, which impairs the hydrolysis of the carbohydrate fractions. Hydrodynamic cavitation (HC) and Advanced Oxidative Processes (AOPs) has been proposed as innovative pretreatment strategies aiming to reduce process time and chemical inputs. Therefore, the underlying mechanisms, procedural strategies, influence on biomass structure, and research gaps were critically discussed in this review. The performed discussion can contribute to future developments, giving a wide overview of the main involved aspects.

Histone Modifications and Their Targeting in Lymphoid Malignancies

In a wide range of lymphoid neoplasms, the process of malignant transformation is associated with somatic mutations in B cells that affect the epigenetic machinery. Consequential alterations in histone modifications contribute to disease-specific changes in the transcriptional program. Affected genes commonly play important roles in cell cycle regulation, apoptosis-inducing signal transduction, and DNA damage response, thus facilitating the emergence of malignant traits that impair immune surveillance and favor the emergence of different B-cell lymphoma subtypes. In the last two decades, the field has made a major effort to develop therapies that target these epigenetic alterations. In this review, we discuss which epigenetic alterations occur in B-cell non-Hodgkin lymphoma. Furthermore, we aim to present in a close to comprehensive manner the current state-of-the-art in the preclinical and clinical development of epigenetic drugs. We focus on therapeutic strategies interfering with histone methylation and acetylation as these are most advanced in being deployed from the bench-to-bedside and have the greatest potential to improve the prognosis of lymphoma patients.

RANK links senescence to stemness in the mammary epithelia, delaying tumor onset but increasing tumor aggressiveness

Rank signaling enhances stemness in mouse and human mammary epithelial cells (MECs) and mediates mammary tumor initiation. Mammary tumors initiated by oncogenes or carcinogen exposure display high levels of Rank and Rank pathway inhibitors have emerged as a new strategy for breast cancer prevention and treatment. Here, we show that ectopic Rank expression in the mammary epithelia unexpectedly delays tumor onset and reduces tumor incidence in the oncogene-driven Neu and PyMT models. Mechanistically, we have found that ectopic expression of Rank or exposure to Rankl induces senescence, even in the absence of other oncogenic mutations. Rank leads to DNA damage and senescence through p16/p19. Moreover, RANK-induced senescence is essential for Rank-driven stemness, and although initially translates into delayed tumor growth, eventually promotes tumor progression and metastasis. We uncover a dual role for Rank in the mammary epithelia: Rank induces senescence and stemness, delaying tumor initiation but increasing tumor aggressiveness.

Can pre-eclampsia explain higher cesarean rates in the different groups of Robson's classification?

OBJECTIVE

To evaluate the impact of pre-eclampsia on cesarean delivery by using the Robson classification.

METHODS

A retrospective cross-sectional study including all women who delivered in a referral maternity hospital in southeast Brazil from January 2017 to February 2018. Women were classified into 1 of 10 Robson groups and then further subdivided into pre-eclampsia (PE) and non-PE (NPE) groups. Frequency of cesarean was determined for each group and compared by using χ² and prevalence ratio.

RESULTS

Overall, 3102 women were included, of whom 1578 (50.9%) delivered by cesarean. Classification in Robson group 5 was the most frequent among all women (n=727, 23.4%). In the PE group (n=258, 8.3%), group 10 was the most frequent classification (n=120, 46.5%); in NPE, Robson group 5 was the most frequency (n=682, 24.0%). Pre-eclampsia was associated with a higher occurrence of cesarean (77.5% vs 48.4%; prevalence ratio, 2.29; 95% confidence interval, 1.82-2.82), owing to higher rates in Robson groups 1, 5, and 10.

CONCLUSION

Pre-eclampsia was associated with a higher occurrence of cesarean delivery in some Robson groups. Robson classification may be used to evaluate the impact of specific conditions at a facility level to help plan future interventions to optimize the use of cesarean.

Leadership and mentoring in medical physics: The experience of a medical physics international mentoring program

Mentoring aims to improve careers and create benefits for the participants' personal and professional lives. Mentoring can be an individual or a shared experience for a group, while the mentor's role remains the same in both models. Mentors should increase confidence, teach, inspire, and set examples, helping the mentees to mould their path, contributing to the pursuit of their personal and professional goals. This study aims to report on the experience of early-career medical physics professionals and postgraduate students participating in a global mentoring program and to assess the impact of this activity on their professional development. The objectives of this mentoring program are to develop leadership roles among young medical physicists and to provide guidance and support. An online questionnaire was administered to the mentee participants. The analysis of their responses is reported in this work and the current status of the programme was examined using a SWOT analysis. In general, the mentoring experience had a positive impact on the mentees. The mentors were found especially helpful in the decision-making situations and in other conflicts that may arise with career development. Additionally, the mentees felt that mentoring contributed to the development of leadership skills required for the job market and assist in personal development. This paper concludes that participation of young medical physicists in a mentoring group program is beneficial to their career and therefore should be encouraged.

Uncertainty estimation and statistical comparative methodology for mammography x-ray energy spectra

Numerical models are an alternative to measurements of x-ray energy spectra when validated by comparative methods that assess the similarity of experimental and calculated spectra. In this work, we compared x-ray energy spectra using several methodologies and determined the methodology with highest statistical power among them. Experiments and Monte Carlo (MC) simulations were used to generate a set of 65 experimental and simulated x-ray mammography spectra pairs typically used in mammography applications. They were generated using Tungsten and Molybdenum targets and Molybdenum and Rhodium filters. The x-ray beams were transmitted through breast tissue equivalent material (bTEM) plates with different glandularities and thicknesses, and the transmitted beam was detected using solid-state x-ray spectrometry with a Cadmium Telluride (CdTe) diode. The MC simulations used the PENELOPE code. Additional uncertainties, beyond that from counting, were propagated using the MC method. Quantitative comparative methods based on the [Formula: see text] statistics, the first and second half-value layers, the mean energy, the effective energy, and the non-parametric u-test were applied and their specificity (true negative rate) was assessed. The polyenergetic normalized glandular dose (DgNp) to a 6 cm breast of 50/50 glandularity was derived from the spectra. In this work, the [Formula: see text] statistics attained the highest score; therefore, it is the most indicated metric for the x-ray energy spectra comparative evaluations. The contribution of the additional uncertainties was important, being responsible for up to 98% of the spectra total uncertainty and shifting the mean of the evaluated [Formula: see text] to 1.2(1), compatible with its expected value. The use of non-parametric test is discouraged by our results, since it failed to distinguish spectra pairs that resulted in up to 72% discrepant DgNp.

Pretreatment of sugarcane bagasse using hydrodynamic cavitation technology: Semi-continuous and continuous process

Development of new technologies for pretreatment of lignocellulosic biomass is a current research challenge. In this way, hydrodynamic cavitation (HC) was used to assist alkaline hydrogen peroxide pretreatment of sugarcane bagasse (SCB) in sequential batches (SB-HC), semi-continuous (SC-HC) and continuous (C-HC) processes. Pretreatment resulted in compositional modifications in the material, mainly regarding the cellulose and lignin contents. The released sugars after enzymatic hydrolysis resulted, on average, in 42 g and 32-35 g of glucose per 100 g of SCB for samples treated in B-HC (10 min of process) and SC-HC process (7.5 min residence time), respectively. In C-HC process, with an average residence time of 7.5 min and 3.75 min, 38-46 g and 32-38 g of glucose per 100 g of SCB were obtained respectively in enzymatic hydrolysis step. HC technology was shown as a promising alternative for pretreatment of lignocellulosic biomass in all evaluated configurations aiming to produce high value bioproducts.

Geographical Distribution of Schizotetranychus hindustanicus and Associated Mites in Roraima, Brazil

The Hindustan citrus mite, Schizotetranychus hindustanicus Hirst (Acari: Tetranychidae), is a quarantine pest present in the state of Roraima, Brazil. This mite, which was described in India in 1924, was reported in 2002 in Venezuela and spread to Roraima, where it was reported in 2008, and to Colombia, where it was reported in 2010. Its possible spread to other regions of Brazil is a threat to Brazilian citriculture. This study reports the current distribution of S. hindustanicus and potential predators of this pest and other mites associated with citrus in Roraima. A survey was conducted in August and September 2015 in the 15 municipalities of the state. In each municipality, orchards and citrus plants in backyards and public areas along highways and in urban areas were sampled. Samples of leaves and fruits were collected to identify the mite and its natural enemies. Schizotetranychus hindustanicus was found in all 15 municipalities in the state of Roraima. In total, 308 associated mites were found, with S. hindustanicus being the most abundant phytophagous mite, followed by Brevipalpus yothersi Baker. Amblyseius aerialis (Muma) was the most abundant predator, followed by Iphiseiodes zuluagai Denmark and Muma and Euseius concordis (Chant). The broad dispersal of S. hindustanicus in Roraima increases the risks of this pest reaching the main citrus-producing regions in Brazil.

Preventive therapy compliance in pediatric tuberculosis - A single center experience

INTRODUCTION

Despite its importance, there are some barriers to patient compliance in preventive therapy (PT) of tuberculosis (TB). The purpose of this study was to evaluate the compliance to appointments, PT and follow-up in a pediatric population after TB exposure, followed in a single TB outpatient center, and the subsequent identification of compliance determinants.

METHODS

Retrospective analysis of all pediatric patients who underwent PT in Gaia TB outpatient center from January 2015 to June 2016. Patients were divided into two groups: compliant and non-compliant, according to adherence to screening, visits and medication. The data collection was based on review of medical records.

RESULTS

A total of 72 patients were enrolled, 33 (45.8%) on chemoprophylaxis and 39 (54.2%) on latent tuberculosis infection (LTBI) treatment. The majority of patients were compliant (63.9%, n=46). Non-compliance was found in 36.1% (n=26): in 12 patients to contact screening, in 11 patients to PT and 22 patients did not attend medical appointments in the first place. In 10 patients, non-compliance was related to social problems/family dysfunction (low socioeconomic status and parent's unemployment). After putting in place several strategies, such as telephone contact, activating social services and direct observation of therapy, a compliance of 98.6% was achieved. Isoniazid was the main drug used (91.7%), during 9 months for LBTI.

CONCLUSION

PT compliance in TB can be challenging, probably related to the lack of risk perception and caregiver's reluctance to undergo a prolonged treatment to an asymptomatic condition. We conclude that implementing interventions can considerably improve treatment compliance and reduce the risk of future tuberculosis development. We emphasize the success in compliance to a 9 month regimen of isoniazid in the vast majority of patients with LTBI.

Extracellular L-asparaginase production in solid-state fermentation by using sugarcane bagasse as support material

L-asparaginase is an important enzyme used in the pharmaceutical and food industry, which can be produced by different microorganisms using low cost feedstocks. In this work, sugarcane bagasse (SCB) was used as support for enzyme production in solid-state fermentation (SSF) by A. terreus. Initially, the influence of the variables carbon and nitrogen sources on the enzyme production was studied following an experimental design carried out in Erlenmeyer flasks. Statistical analysis indicated the use of 0.54% of starch, 0% of maltose, 0.44% of asparagine, and 1.14% of glutamine in the medium, resulting in enzyme activity per volume of produced extract of 120.723 U/L. Then, these conditions were applied in a horizontal column reactor filled with SCB, producing 105.3 U/L of enzyme activity. Therefore, the potential of extracellular L-asparaginase enzyme production in the column reactor using sugarcane bagasse as support was demonstrated and it represents a system that can favor large scale production.

Biodegradable alternative for removing toxic compounds from sugarcane bagasse hemicellulosic hydrolysates for valorization in biorefineries

Among the major challenges for hemicellulosic hydrolysate application in fermentative processes, there is the presence of toxic compounds generated during the pretreatment of the biomass, which can inhibit microbial growth. Therefore, the development of efficient, biodegradable and cost-effective detoxification methods for lignocellulosic hydrolysates is crucial. In this work, two tannin-based biopolymers (called A and B) were tested in the detoxification of sugarcane bagasse hydrolysate for subsequent fermentation by Candida guilliermondii. The effects of biopolymer concentration, pH, temperature, and contact time were studied using a 2⁴ experimental design for both biopolymers. Results revealed that the biopolymer concentration and the pH were the most significant factors in the detoxification step. Biopolymer A removed phenolics, 5-hydroxymethylfurfural, and nickel from the hydrolysate more efficiently than biopolymer B, while biopolymer B was efficient to remove chromium at 15% (v/v). Detoxification enhanced the fermentation of sugarcane bagasse hydrolysate, and the biopolymers showed different influences on the process.

Evaluation of mean conversion coefficients from air-kerma to H *(10) using secondary and transmitted x-ray spectra in the diagnostic radiology energy range

Ambient dose equivalent H ^*(10) is an operational quantity recommended by the IAEA to establish dose constraints in area monitoring for external radiation. The direct measurement of H ^*(10) is not common due to the complexity in the calibration procedures of radiation monitors involving the use of expanded and aligned radiation fields. Therefore, conversion coefficients are used to assess H ^*(10) from the physical quantity air-kerma. Conversion coefficients published by international commissions, ICRU and ICRP, present a correlation with the radiation beam quality. However, Brazilian regulation establishes 1.14 Sv Gy^-1 as unique conversion coefficient to convert air-kerma into H ^*(10), disregarding its beam quality dependence. The present study computed mean conversion coefficients from secondary and transmitted x-ray beams in order to improve the current assessment of H ^*(10). The weighting of conversion coefficients corresponding to monoenergetic beams with the spectrum energy distribution in terms of air-kerma was used to compute the mean conversion coefficients. In order to represent dedicated chest radiographic facilities, an anthropomorphic phantom was used as scatter object of the primary beam. Secondary x-ray spectra were measured in the diagnostic energy range at scattering angles of 30°, 60°, 90° 120° and 150° degrees. Barite mortar plates were used as attenuator of the secondary beam to produce the corresponding transmitted x-ray spectra. Results show that the mean conversion coefficients are about 43% higher than the recommended value accepted by Brazilian regulation. For secondary radiation measured at 100 kV the mean coefficient should be 1.46 Sv Gy^-1, which represent the higher value in the mean coefficient set corresponding to secondary beams. Moreover, for transmitted x-ray beams at 100 kV, the recommended mean conversion coefficient is 1.65 Sv Gy^-1 for all barite mortar plate thickness and all scattering angles. An example of application shows the discrepancy in the evaluation of secondary shielding barriers in a controlled area when the shielding goals is evaluated. The conclusion based on these results is that a unique coefficient may not be adequate for deriving the H ^*(10).

Helicobacter pylori infection modulates the expression of miRNAs associated with DNA mismatch repair pathway

Genetic and epigenetic inactivation of DNA mismatch repair (MMR) genes might lead to modifications in cancer-related gene expression and cancer development. Recently, it has been shown that the infection by Helicobacter pylori, the major causative agent of gastric cancer, induces DNA damage and inhibits MMR DNA repair. Also, it has been reported that microRNAs (miRs) have an important role in regulating genomic stability and MMR DNA repair. Thus, the aim of this study was to identify miRs regulating MMR pathway in H. pylori-associated gastric carcinogenesis. To address this question, a gastric epithelial cell line and AGS cancer gastric cells were infected with several H. pylori strains. MMR gene expression and miRs correlating with H. pylori strain infection were evaluated. The results showed that H. pylori infection significantly down-regulated the expression of all selected MMR genes. Also, H. pylori infection modulated the expression of several miRs (including miR-150-5p, miR-155-5p, and miR-3163), after 4, 8, and 12 h of infection. Computational prediction of candidate miRs and their predicted MMR targeting sites were obtained from TargetScan, mirDB, and MetaCore. The generated data indicated that the selected miRs (miR-150-5p, miR-155-5p, and miR-3163) could possibly target and modulate MMR genes (POLD3, MSH2, and MSH3, respectively). The target validation was performed using mimics and luciferase gene reporter assays. Briefly, this study shows that H. pylori impairs MMR DNA repair pathway and identifies miRs that regulate MMR gene expression in gastric cancer. © 2016 Wiley Periodicals, Inc.

How detrimental are seed galls to their hosts? Plant performance, germination, developmental instability and tolerance to herbivory in Inga laurina, a leguminous tree

Gall inducers use these structures as shelters and sources of nutrition. Consequently, they cause multiple physiological changes in host plants. We studied the impact caused by seed coat galls of a braconid wasp on the performance of fruits, seeds and seedlings of tree Inga laurina. We tested whether these seed galls are 'nutrient sinks' with respect to the fruit/seed of host plant, and so constrain the reproductive ability and reduce seedling longevity. We measured the influence of such galls on the secondary compounds, fruit and seed parameters, seed viability and germination and seedling performance. Inga laurina has indehiscent legumes with polyembryonic seeds surrounded by a fleshy sarcotesta rich in sugars. The galls formed inside the seed coat and galled tissues presented higher phenol concentrations, around 7-fold that of ungalled tissues. Galls caused a significant reduction in parameters such as fruit and seed size, seed weight and the number of embryos. Fluctuating asymmetry (a stress indicator) was 31% higher in leaves of galled seed plants in comparison to ungalled seed plants. However, the negative effects on fruit and seed parameters were not sufficient to reduce seed germination (except the synchronization index) or seedling performance (except leaf area and chlorophyll content). We attributed these results to the ability of I. laurina to tolerate gall attack on seeds without a marked influence on seedling performance. Moreover, because of the intensity of seed galling on host plant, we suggest that polyembryony may play a role in I. laurina reproduction increasing tolerance to seed damage.

Paradoxical role of SOX2 in gastric cancer

Sox2 is a critical regulator of embryogenesis and necessary for cellular reprogramming. It also plays an important role in tissue homeostasis and regeneration, maintaining the population of undifferentiated adult stem cells. Like various developmental and stem cell genes, SOX2 is aberrantly expressed and amplified in several human cancers. Moreover, functional studies have shown that it regulates many biological processes including cell proliferation, apoptosis, self-renewal and invasion. While it is oncogenic in most cancers, SOX2 activity is controversial in gastric cancer, where it might behave as a tumor suppressor in some situations. In this review, we discuss its role in cancer biology, with particular attention to what is known about the involvement of SOX2 in gastric cancer biology.

Evaluation of conversion coefficients relating air-kerma to H*(10) using primary and transmitted x-ray spectra in the diagnostic radiology energy range

According to the International Commission on Radiation Units and Measurements (ICRU), the relationship between effective dose and incident air-kerma is complex and depends on the attenuation of x-rays in the body. Therefore, it is not practical to use this quantity for shielding design purposes. This correlation is adopted in practical situations by using conversion coefficients calculated using validated mathematical models by the ICRU. The ambient dose equivalent, H*(10), is a quantity adopted by the IAEA for monitoring external exposure. Dose constraint levels are established in terms of H*(10), while the radiation levels in radiometric surveys are calculated by means of the measurements of air-kerma with ion chambers. The resulting measurements are converted into ambient dose equivalents by conversion factors. In the present work, an experimental study of the relationship between the air-kerma and the operational quantity ambient dose equivalent was conducted using different experimental scenarios. This study was done by measuring the primary x-ray spectra and x-ray spectra transmitted through materials used in dedicated chest radiographic facilities, using a CdTe detector. The air-kerma to ambient dose equivalent conversion coefficients were calculated from these measured spectra. The resulting values of the quantity ambient dose equivalent using these conversion coefficients are more realistic than those available in the literature, because they consider the real energy distribution of primary and transmitted x-ray beams. The maximum difference between the obtained conversion coefficients and the constant value recommended in national and international radiation protection standards is 53.4%. The conclusion based on these results is that a constant coefficient may not be adequate for deriving the ambient dose equivalent.

Successive pretreatment and enzymatic saccharification of sugarcane bagasse in a packed bed flow-through column reactor aiming to support biorefineries

A packed bed flow-through column reactor (PBFTCR) was used for pretreatment and subsequent enzymatic hydrolysis of sugarcane bagasse (SCB). Alkaline pretreatment was performed at 70 °C for 4h with fresh 0.3M NaOH solution or with liquor recycled from a previous pretreatment batch. Scheffersomyces stipitis NRRL-Y7124 was used for fermentation of sugars released after enzymatic hydrolysis (20 FPU g(-1) of dry SCB). The highest results for lignin removal were 61% and 52%, respectively, observed when using fresh NaOH or the first reuse of the liquor. About 50% of cellulosic and 57% of hemicellulosic fractions of pretreated SCBs were enzymatically hydrolyzed and the maximum ethanol production was 23.4 g L(-1) (ethanol yield of 0.4 gp gs(-1)), with near complete consumption of both pentoses and hexoses present in the hydrolysate during the fermentation. PBFTCR as a new alternative for SCB-biorefineries is presented, mainly considering its simple configuration and efficiency for operating with a high solid:liquid ratio.

Shelter-Building Insects and Their Role as Ecosystem Engineers

Amelioration of harsh conditions, manipulation of host plant quality, and protection from natural enemies have all been suggested as potential forces in the evolution and maintenance of concealed feeding in insects. The construction of shelters--either in the form of mines, galls, and leaf rolls--are expected to increase larval survivorship and might influence other organisms of the community through non-trophic direct and indirect effects when shelters are co-occupied or occupied after abandonment, placing leaf and stem shelter-builders within the context of ecosystem engineering. In this review, we evaluate the potential of shelter built by insects to reduce pressure exerted by natural enemies, increase tissue quality, and provide shelter against abiotic conditions experienced during insect development. Through a quantitative analysis, we also examined the effects of insect shelters on patterns of richness and abundance of local communities, reviewing the data published in the last 15 years. We demonstrate strong effects of shelters on several arthropods, with increased richness and abundance when shelters are present in the host plants. These results reinforce the importance of the physical structures created by insects that although subtle, might have important roles in facilitative interactions.

Abstract 2412: The modulatory effects of H. pylori infection in the DNA mismatch repair

The bacterial pathogen H. pylori chronically infects the human gastric mucosa and is the leading risk factor for the development of gastric cancer. It is believed that during the infection the organism causes an impairment of DNA repair in the gastric epithelium. Thus, we evaluated the in vitro modulatory effects of H. pylori infection in the DNA mismatch repair (MMR).

To evaluate the effects of H. pylori on MMR, AGS gastric carcinoma cell line and the H. pylori strain P12 were used in co-culture experiments for 4, 8 and 12 h. In addition, to analyze the potential effects of virulence factors on MMR, the ΔcagPAI, ΔvacA, ΔbabA, ΔhopQ, and Δtfs4 mutants were also subjected to co-culture experiments. The expression levels of EXO1, MLH1, MSH2, MSH3, MSH6, POLD3, PMS1, and PMS2 were assessed by real-time PCR. Moreover, expression levels of five previously screened miRNAs (miR-142-5p, miR-150-5p, miR-155-5p, miR-3163, and miR-4775), which are predicted to target MMR genes, were also evaluated by real-time PCR.

Our data show that H. pylori infection significantly down-regulates the expression of all selected genes. Regarding the virulence factors, the results suggest that the modulation on gene expression might be dependent on cagPAI, vacA, and the type IV secretion (TFS4) system. Although the infection up-regulates miR-150-5p, miR-155-5p, miR-3163, and miR-4775, only the expression of miR-155-5p is related with virulence factors.

Briefly, this study shows that H. pylori regulates the expression of several MMR genes, and it may be related with cagPAI, vacA, and the TFS4 system. Taking into account that MLH1, MSH2, and MSH6 are the miR-155-5p predicted targets, these preliminary data suggest that the observed virulence factor-dependent repression of miR expression could be responsible for the down-regulation of these MMR genes.

Citation Format: Juliana C. Santos, Victor R. de Almeida, Wolfgang Fischer, Rainer Haas, Marcelo L. Ribeiro. The modulatory effects of H. pylori infection in the DNA mismatch repair. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2412. doi:10.1158/1538-7445.AM2014-2412

Effect of MLH1 -93G>A on gene expression in patients with colorectal cancer

The DNA repair machinery plays a key role in maintaining genomic stability by preventing the emergence of mutations. Furthermore, the -93G>A polymorphism in the MLH1 gene has been associated with an increased risk of developing colorectal cancer. Therefore, the aim of this study was to examine the expression pattern and effect of this polymorphism in normal and tumour samples from patients with colorectal cancer. The MLH1 -93G>A (rs1800734) polymorphism was detected by PCR-RFLP in 49 cases of colorectal cancer. MLH1 expression was investigated using real-time quantitative PCR. The results indicate a significant decrease in MLH1 expression in tumour samples compared to their normal counterparts. The MLH1 gene was also significantly repressed in samples from patients who had some degree of tumour invasion into other organs. Similarly, those patients who were in a more advanced tumour stage (TNM III and IV) exhibited a significant reduction in MLH1 gene expression. Finally, the mutant genotype AA of MLH1 was associated with a significant decrease in the expression of this gene. This finding suggests that this polymorphism could increase the risk of developing colorectal cancer by a defective mismatch repair system, particularly through the loss of MLH1 expression in an allele-specific manner.

Illustrated and annotated checklist of Brazilian gall morphotypes

The analysis on nine inventories on the richness and diversity of galling herbivores in Brazil accounted for 806 gall systems occurring in 443 host-plant species from 74 plant families. This checklist of the Brazilian gall morphotypes proposes seven standardized morphotypes and five additional shapes that group the majority of the three-dimensional shapes reported in literature. Criteria are proposed to standardize the terminology, and a critical analysis is provided aiming to avoid possible inconsistencies in order to generate easily comparable data in future inventories. The morphotypes are herein catalogued in alphabetical order, accompanied by a conceptual definition, an illustration, and examples that best represent the shape. It is proposed that the inventories should present at least the (1) host-plant species, (2) galling herbivore species or its identification to the lowest possible taxonomic level, (3) host-plant galled organ and gall position, (4) gall morphotype, (5) gall color and registration of indumentum when present, (6) gall phenological and developmental data, (7) association with other trophic levels, and (8) additional information, such as dimension, and number of chamber(s).

MGMT and MLH1 methylation in Helicobacter pylori-infected children and adults

AIM: To evaluate the association between Helicobacter pylori (H. pylori) infection and MLH1 and MGMT methylation and its relationship with microsatellite instability (MSI).

METHODS: The methylation status of the MLH1 and MGMT promoter region was analysed by methylation specific methylation-polymerase chain reaction (MSP-PCR) in gastric biopsy samples from uninfected or H. pylori-infected children (n = 50), from adults with chronic gastritis (n = 97) and from adults with gastric cancer (n = 92). MLH1 and MGMT mRNA expression were measured by real-time PCR and normalised to a constitutive gene (β actin). MSI analysis was performed by screening MSI markers at 4 loci (Bat-25, Bat-26, D17S250 and D2S123) with PCR; PCR products were analysed by single strand conformation polymorphism followed by silver staining. Statistical analyses were performed with either the χ² test with Yates continuity correction or Fisher’s exact test, and statistical significance for expression analysis was assessed using an unpaired Student’s t-test.

RESULTS: Methylation was not detected in the promoter regions of MLH1 and MGMT in gastric biopsy samples from children, regardless of H. pylori infection status. The MGMT promoter was methylated in 51% of chronic gastritis adult patients and was associated with H. pylori infection (P < 0.05); this region was methylated in 66% of gastric cancer patients, and the difference in the percentage of methylated samples between these patients and those from H. pylori-infected chronic gastritis patients was statistically significant (P < 0.05). MLH1 methylation frequencies among H. pylori-infected and non-infected chronic gastritis adult patients were 13% and 7%, respectively. We observed methylation of the MLH1 promoter (39%) and increased MSI levels (68%) in samples from gastric cancer patients in comparison to samples from H. pylori-infected adult chronic gastritis patients (P < 0.001 and P < 0.01, respectively). The frequency of promoter methylation for both genes was higher in gastric cancer samples than in H. pylori-positive chronic gastritis samples (P < 0.05). The levels of MLH1 and MGMT mRNA were significantly reduced in chronic gastritis samples that were also hypermethylated (P < 0.01).

CONCLUSION: In summary, MGMT and MLH1 methylation did not occur in earlier-stage H. pylori infections and thus might depend on the duration of infection.

Oogenesis pattern and type of ovariole of the parasitoid Palmistichus elaeisis (Hymenoptera: Eulophidae)

The knowledge on ovigeny in parasitoids is important for basic studies on physiology and applied biological control. The ovigeny pattern and type of ovariole of the parasitoid Palmistichus elaeisis Delvare & LaSalle (Hymenoptera: Eulophidae) were studied in newly-emerged females at seven, 14, 24 and 48 h intervals after their emergence from Tenebrio molitor L. pupae (Coleoptera: Tenebrionidae). Females of P. elaeisis presented ovaries composed by four ovarioles of the meroistic polytrophic type. The yolk accumulation and chorionogenesis in P. elaeisis were concluded 24 h after the female emergence. The 48 h-old females show a high quantity of egg ready for oviposition. These findings can help to improve the mass production of P. elaeisis and the augmentative biological control by using this natural enemy.

Up-regulation of chemokine C-C ligand 2 (CCL2) and C-X-C chemokine 8 (CXCL8) expression by monocytes in chronic idiopathic urticaria

The disturbed cytokine-chemokine network could play an important role in the onset of diseases with inflammatory processes such as chronic idiopathic urticaria (CIU). Our main objectives were to evaluate the relation between proinflammatory chemokine serum levels from CIU patients and their response to autologous skin test (ASST) and basophil histamine release (BHR). We also aimed to assess the chemokine secretion by peripheral blood mononuclear cells (PBMC) upon polyclonal stimulus and to evaluate chemokine C-C ligand 2/C-X-C chemokine 8 (CCL2/CXCL8) and Toll-like receptor-4 (TLR-4) expression in monocytes. We observed significantly higher serum levels of the CXCL8, CXCL9, CXCL10 and CCL2 in CIU patients compared to the healthy group, regardless of the BHR or ASST response. The basal secretion of CCL2 by PBMC or induced by Staphylococcus aureus enterotoxin A (SEA) was higher in CIU patients than in the control group, as well as for CXCL8 and CCL5 secretions upon phytohaemagglutinin stimulation. Also, up-regulation of CCL2 and CXCL8 mRNA expression was found in monocytes of patients upon SEA stimulation. The findings showed a high responsiveness of monocytes through CCL2/CXCL8 expression, contributing to the creation of a proinflammatory environment in CIU.

Diversity of gall-inducing insects in the high altitude wetland forests in Pernambuco, Northeastern Brazil

We report on the richness of galling insects in the altitudinal wetland forests of Pernambuco State, Northeastern Brazil. We found 80 distinct types of insect galls on 49 species of host plants belonging to 28 families and 35 genera. Most of the galled plant species belong to Nyctaginaceae, Fabaceae, Meliaceae, Sapindaceae and Myrtaceae. The most common gall were spheroid and globoid; most galls were glabrous, predominantly green and with one chamber, and on the leaves. Most galls were induced by Cecidomyiidae (Diptera). The results of this study contribute to existing knowledge richness of galling insects and host-plant diversity in the altitudinal wetland forests of Northeastern Brazil.

Plant Vigor Hypothesis refuted: preference-performance linkage of a gall-inducing weevil on small-sized host plant resources

The Plant Vigor Hypothesis (PVH) predicts an oviposition preference of females and higher offspring performance for insect herbivores on longer and fast-growing plant modules. We tested the PVH predictions by investigating the effects of leaf size of Miconia prasina (Sw.) DC. (Melastomataceae) on the oviposition preference and on the offspring survival of the gall-inducing weevil Prospoliata bicolorata (Coleoptera: Curculionidae). Additionally, we analysed the effects of top-down mortality force on this system. Approximately 83% of the developed galls resulted in adults of P. bicolorata, whereas 17% of the galls successfully induced were killed by natural enemies (top-down effect). Leaves of intermediate size were more abundant while smaller and longer leaves were rare. Nevertheless, the percentage of P. bicolorata galls was higher on the smallest leaves of M. prasina, refuting the preference prediction of the PVH. Our results also refuted the performance prediction: the ratio of survival per leaf was negatively related to the leaf length. Thus, we found a link between female preference and larval performance of P. bicolorata on small-sized leaves of M. prasina. The next goal is to understand the mechanisms involved in the selection of gall-inducing weevil on short leaves of its host plant.

Activated status of basophils in chronic urticaria leads to interleukin-3 hyper-responsiveness and enhancement of histamine release induced by anti-IgE stimulus

BACKGROUND

Basophils and mast cells are the main target cells in chronic idiopathic urticaria (CIU). Besides the basopenia, intrinsic defects of the anti-IgE cross-linking signalling pathway of basophils have been described in CIU.

OBJECTIVES

We sought to investigate the profile of expression of activation markers on basophils of patients with CIU and to explore the effect of interleukin (IL)-3 priming upon anti-IgE cross-linking stimuli through expression of activation markers and basophil histamine releasability.

METHODS

Evaluation of the surface expression of FcepsilonRIalpha, CD63, CD203c and CD123 on whole blood basophils of patients with CIU undergoing autologous serum skin test (ASST) was performed by flow cytometry. The effect of pretreatment with IL-3 in the anti-IgE response was analysed by the expression of basophil activation markers and histamine release using enzyme-linked immunosorbent assay.

RESULTS

Blood basophils of patients with CIU were reduced in number and displayed increased surface expression of FcepsilonRIalpha, which was positively correlated with the IgE serum levels. Upregulation of expression of both surface markers CD203c and CD63 was verified on basophils of patients with CIU, regardless of ASST response. High expression of IL-3 receptor on basophils was detected only in ASST+ patients with CIU. Pretreatment with IL-3 upregulated CD203c expression concomitantly with the excreting function of blood basophils and induced a quick hyper-responsiveness to anti-IgE cross-linking on basophils of patients with CIU compared with healthy controls.

CONCLUSIONS

Basophils of patients with CIU showed an activated profile, possibly due to an in vivo priming. Functionally, basophils have high responsiveness to IL-3 stimulation, thereby suggesting that defects in the signal transduction pathway after IgE cross-linking stimuli are recoverable in subjects with chronic urticaria.

Associations among immunological, parasitological and clinical parameters in canine visceral leishmaniasis: Emaciation, spleen parasitism, specific antibodies and leishmanin skin test reaction

Associations among parameters commonly used as markers of infection by Leishmania sp., or of susceptibility to visceral leishmaniasis, were investigated in 325 stray dogs from an area where this disease is endemic. Evidence of infection (presence of Leishmania in splenic cultures, positive leishmanin skin test (LST) or detection of anti-Leishmania antibody activity in the serum) was found in 57% of the animals. Both evidence of weight loss (chi(2)-test, P=0.0005) and presence of specific antibody activity in the serum (chi(2)-test, P<0.0001) were directly associated with positive splenic culture. The frequencies of animals with positive splenic culture were directly correlated with the intensities of antibody activity in the serum as measured by ELISA (relative risk of 3.4 for animals with moderate antibody levels and relative risk of 8.43 for animals with high-antibody levels). A negative association was observed between positive leishmanin skin test results and emaciation (chi(2), P=0.0089). Furthermore, animals with positive splenic cultures and negative leishmanin skin test results had higher levels of total serum IgG (Kruskal-Wallis test, P=0.001) and IgG2 (Kruskal-Wallis test, P=0.05) than animals with negative splenic cultures, and were more emaciated than animals with negative LST results and positive splenic cultures. The data presented herein suggest that associating these common parameters may improve their performance in predicting susceptibility to canine visceral leishmaniasis.

Repeated-Batch Xylitol Bioproduction Using Yeast Cells Entrapped in Polyvinyl Alcohol–Hydrogel

Xylose-to-xylitol conversion was investigated in a bench-scale bioreactor using Candida guilliermondii cells entrapped within polyvinyl alcohol-hydrogel beads in a system operated in repeated-batch mode with cell recycling. Yeast-viable cells were immobilized in the support using the freezing-thawing method. Bioconversion assays were performed in a stirred tank reactor operated at 400-rpm agitation speed, 30 degrees C temperature, and 1.04-vvm air flow rate. The system was explored during six successive cycles, and a small decrease in the conversion performance in the fifth cycle was observed, but the biocatalytic activity of the microorganism was recovered in the sixth cycle after washing the particles. During the process, the hydrogel beads maintained their shape and size without appreciable deterioration. Xylitol production, yield factor, and volumetric productivity increased with progressive recycling of cells and achieved their maximum values (P(F) = 39.7 g l(-1); Y(P/S) = 0.77 g g(-1); Q(P) = 0.53 g l(-1) h(-1), respectively) after the third cell recycling, probably because of cells' adaptation to the medium.

Sigma-pi separation of the electron localization function and aromaticity

The electron localization function (ELF) has been separated in its sigma and pi components. The topological analysis of the new ELFsigma and ELFpi functions has been used to quantify the concept of resonance. The highest bifurcation values of these functions describe in a correct way the aromaticity of classical ring molecules and some new aromatic compounds as B6CO6, Al4(2-), and N5-. In the case of Al4(2-), an important sigma delocalization contribution has been found, which is in agreement with previous interpretation.

Survey of acarine fauna in dust samplings of curtains in the city of Campinas, Brazil

The aim of this study was to investigate the mite fauna present in 33 living room and 22 bedroom curtain dust samples from 41 different homes in the southern Brazilian city of Campinas, SP. A total of 148 mite bodies were found. Of these, 83 were found in living-room curtain samples (56.1% of total) and 65 were in bedroom curtain dust samples (43.9%). The most frequently observed mite suborders were: Acaridida (n = 79; 53.4%), Actinedida (n = 53; 35.8%), Oribatida (n = 14; 9.5%), and Gamasida (n = 2; 1.3%). The most frequent families were Pyroglyphidae (n = 61; 41.2%), Eriophyidae (n = 25; 16.9%), Tarsonemidae (n = 15; 10.1%), and Glycyphagidae (n = 13; 8.8%). No statistical difference was observed between the number of mites found in the samples from living room and bedroom curtains.

Xylitol production from sugarcane bagasse hydrolyzate in fluidized bed reactor. Effect of air flowrate

Cells of Candida guilliermondii immobilized onto porous glass spheres were cultured batchwise in a fluidized bed bioreactor for xylitol production from sugarcane bagasse hemicellulose hydrolyzate. An aeration rate of only 25 mL/min ensured minimum yields of xylose consumption (0.60) and biomass production (0.14 g(DM)/g(Xyl)), as well as maximum xylitol yield (0.54 g(Xyt)/g(Xyl)) and ratio of immobilized to total cells (0.83). These results suggest that cell metabolism, although slow because of oxygen limitation, was mainly addressed to xylitol production. A progressive increase in the aeration rate up to 140 mL/min accelerated both xylose consumption (from 0.36 to 0.78 g(Xyl)/L.h) and xylitol formation (from 0.19 to 0.28 g(Xyt)/L.h) but caused the fraction of immobilized to total cells and the xylitol yield to decrease up to 0.22 and 0.36 g(Xyt)/g(Xyl), respectively. The highest xylitol concentration (17.0 g(Xyt)/L) was obtained at 70 mL/min, but the specific xylitol productivity and the xylitol yield were 43% and 22% lower than the corresponding values obtained at the lowest air flowrate, respectively. The concentrations of consumed substrates and formed products were used in material balances to evaluate the xylose fractions consumed by C. guilliermondii for xylitol production, complete oxidation through the hexose monophosphate shunt, and cell growth. The experimental data collected at variable oxygen level allowed estimating a P/O ratio of 1.35 mol(ATP)/mol(O) and overall ATP requirements for biomass growth and maintenance of 3.4 mol(ATP)/C-mol(DM).

Effect of pentagastrin on the motor activity of the dilated and nondilated sigmoid and rectum in Chagas' disease

In order to evaluate the effect of pentagastrin on the motor activity of the sigmoid and rectum in patients with Chagas' disease, manometric studies were performed on 22 chagasic patients, 11 without and 11 with megacolon, and 11 control subjects. Pentagastrin had a stimulating effect on the sigmoid and rectum in control subjects as well as in chagasic patients without megacolon. In chagasic patients with megacolon, pentagastrin had no effect on sigmoid or rectum motility, probably as a result of the intrinsic denervation known to occur in this disease. The findings suggest that the motor effect of pentagastrin on the human sigmoid and rectum depends on the myenteric nervous pathways.

[Cyclosporin A inhibits the response of osmotic water permeability to antidiuretic hormone in toad's bladder and to angiotensin II and antidiuretic hormone in toad's skin]

The purpose of the present study was to assess the effects of cyclosporine A (CyA) in the osmotic water flow response of isolated toad bladder to arginine-vasotocin (AVT) and to angiotensin II (Ang II) and AVT in isolated toad skin. CyA added to the dermal side of isolated toad skin or to the serosal side of toad bladder in concentrations of 0.42. 10(-6) M to 0.42. 10(-7) M had no effect on basal osmotic water permeability (Posm) but inhibited the hormonal response to AVT in both membranes (AVT 10(-10) M in toad bladder and 10(-8) to 10(-9) M in toad skin). CyA also inhibited the Posm response to Ang II (10(-7) M) in toad skin in concentrations of 0.42. 10(-6) M and 0.42. 10(-7) M. In toad bladder it could be demonstrated that the inhibitory effect was reversible. CyA in concentrations of 0.42. 10(-6) M inhibited the Posm response of toad skin to theophylline (3.2. 10(-3) M) and to dibutyryl cyclic AMP (6.3. 10(-3) M) suggesting an effect distal to the generation of cyclic AMP. These responses would support the possibility of a diuretic effect in the mammalian nephron.

Angiotensin-(1-7) increases osmotic water permeability in isolated toad skin

Angiotensin-(1-7) (Ang-(1-7)) increased osmotic water permeability in the isolated toad skin, a tissue with functional properties similar to those of the distal mammalian nephron. Concentrations of 0.1 to 10 microM were effective, with a peak at 20 min. This effect was similar in magnitude to that of frog skin angiotensin II (Ang II) and oxytocin but lower than that of human Ang II and arginine-vasotocin. The AT2 angiotensin receptor antagonist PD 123319 (1.0 microM) fully inhibited the response to 0.1 microM Ang-(1-7) but had no effect on the response to Ang II at the same concentration. The specific receptor antagonist of Ang-(1-7), A-779, was ineffective in blocking the response to Ang-(1-7) and to frog skin Ang II. The AT1 receptor subtype antagonist losartan, which blocked the response to frog skin Ang II, was ineffective in blocking the response to Ang-(1-7). The present results support the view of an antidiuretic action of Ang-(1-7) in the mammalian nephron.

[Trends in hospital admissions for pediatric asthma in childrenduring a period of eighteen years]

OBJECTIVE: To study trends in hospital admissions for acute pediatric asthma in the Hospital da Santa Casa do Rio Grande during the period of 1979 to 1996. METHODS: This is a study of a series of cases. We reviewed all the discharge records of pediatric patients with diagnosis of acute asthma, pneumonia, and bronchiolitis within the period mentioned above. The main variable in this study was the percentage of admissions for acute asthma in relation to the total amount of hospital admissions. The percentages of admissions for bronchiolitis and pneumonia in relation to the total amount of hospital admissions were also calculated as reference values. RESULTS: There were 3,493 admissions for acute asthma in 3,122 patients during the studied period, with an average of 194 admissions per year. The percentage of admissions for acute asthma to total hospital admissions increased from 5,5% to 14,7% between 1983/84 and 1991/92. Half of this increase occurred during the period 1987-1992 in which hospitalizations for bronchiolitis and pneumonia were stable. This percentage decreased from 14,7% to 10,6% in the period of 1991/92 - 1995/96. CONCLUSIONS: There was a significant increase in hospital admissions for acute pediatric asthma in the Hospital da Santa Casa do Rio Grande during the period of 1983 - 1992. From then on, hospital admissions for asthma showed downward trends.

Prognostic factors in supraglottic carcinoma patients treated by surgery or radiotherapy

The decision regarding treatment of supraglottic carcinoma remains controversial, despite recent advances in radiotherapy and surgical procedures. The need to evaluate the prognostic importance of demographic, clinical, pathologic, and treatment-related variables prompted this study. The patient population was of 164 consecutive cases of supraglottic carcinoma. Clinical charts were reviewed and cases were restaged according to the 1987 version of the UICC-AJC classification based on the initial clinical description: 18 T1, 30 T2, 58 T3, 58 T4, 61 NO, 24 N1, and 79 N2a-N3. Management policy for these patients varied during the study, reflecting different opinions of the responsible physicians and technical advances. Seventy-seven patients (47%) underwent surgery, patients who underwent surgery and radiotherapy, respectively, remained alive with no evidence of disease. The 5-year actuarial survival rates were 58.5% for patients initially treated by surgery, and 16.3% for patients in the radiotherapy group. Although several demographic, clinical, and pathologic variables were studied, only initial treatment (p <.0001), N stage (p = .0003), and T stage (p = .0017) were deemed to have independent prognostic value by multivariate regression techniques based on Cox's proportional hazards model. This study has shown that survival of supraglottic carcinoma patients depends on the treatment modality, T stage, and N stage. Our results are disappointing with regard to radiotherapy as a treatment for supraglottic carcinoma in patients with tumors at clinical stages III and IV.

Late Miocene Tidal Deposits in the Amazonian Foreland Basin

Late Miocene tidal sediments of Acre, Brazilian Amazonia, were deposited in an embayment or interior seaway located in the sub-Andean zone. This late Tertiary embayment system may once have connected the Caribbean with the South Atlantic. The tidal coasts of the embayment-seaway have provided an avenue for the earliest waif (over water) dispersal phases of the great American biotic interchange in the late Miocene. The subsequent change from semimarine to terrestrial environments is of value in assessing the importance of earlier hypotheses on the evolution of the westem Amazonian landscape and gives insight into the formation of several observed biogeographic patterns, especially of aquatic biota.

Prospective randomized trial of mechanical bowel preparation in patients undergoing elective colorectal surgery

A total of 149 patients admitted for elective colorectal surgery were randomly allocated to receive preoperative mechanical bowel preparation (group 1) or no mechanical bowel preparation (group 2). All patients received antimicrobial prophylaxis with cephalothin and metronidazole. The overall incidence of wound infection was 17.4 per cent (24 per cent for group 1, 12 per cent for group 2) and that of dehiscence 7.4 per cent (10 per cent for group 1, 5 per cent for group 2). The incidence of wound infection was significantly higher in group 1 (P < 0.05) but that of anastomotic dehiscence did not differ significantly between groups. Mechanical bowel preparation is unnecessary and may be harmful in terms of preventing wound infection and anastomotic dehiscence in patients undergoing elective colorectal surgery.