Disfunción endotelial. Mecanismos e implicancias en Covid-19 / Endothelial dysfunction. Mechanisms and implications on Covid-19

Endothelium is the inner layer of vessels that separates circulating blood from the rest of the body tissues. Since its discovery, it has been involved in various functions, both systemic and organ specific. Currently, endothelial damage and failure in its functions is considered a key element in pathophysiology of various clinical scenarios, among which we may find COVID-19.Hence, it has been a target in development of strategies that seek to maintain, enhance or repair its function. The purpose of the following review is to describe what an endothelial function is about, its relation with current medical practice, and its implications in the SARS- CoV-2 pandemic. (AU)

A probabilistic Poisson-based model to detect PRRSV recirculation using sow production records.

Porcine reproductive and respiratory syndrome (PRRS) is a viral disease associated with a decrease in the number of born alive piglets (NBA) and an increase in the number of lost piglets (NLP) per farrowing. Under practical conditions, it is critical to assess whether a farm is suffering PRRSV recirculation in the sow herd as soon as possible. The aim of this research work was to develop a new method to detect potential PRRSV recirculation in sow production farms. Sow reproductive performance records from one farm (farm T) were used to set up the method and records from ten additional farms (farms V1 to V10) were used for validation. A conditional Poisson model of NLP on NBA was proposed to fit the data. A three-step procedure was implemented to detect potential PRRSV recirculation: (i) computation of the maximum-likelihood estimates of the expected values of NBA and NLP in a PRRSV non-recirculating scenario; (ii) calculation, for each farrowing, of the p-value associated with the probability of jointly observing deviations towards decreased NBA and increased NLP. The detection of a potential PRRSV recirculation was based on (iii) the combined p-value resulting from weighing the p-values of the last N farrowings by the chi-square-inverse method. In order to gain specificity, a displacement on the expected non-recirculating NBA and NLP values was used for tuning purposes. With this approach, two PRRSV circulating periods were detected in farm T, which were confirmed with standard laboratorial diagnostic techniques. The method was subsequently validated in farms V1 to V10, where ten PRRSV-recirculating time episodes had been diagnosed. The method proposed here was able to detect the ten PRRSV recirculations using a relatively small set of contiguous farrowings, with only two mismatched weeks, one as a false negative, in farm V1, and one as a false positive, in farm V4. It is concluded that a conditional Poisson-based model of NLP on NBA can be a useful tool for routinely detecting PRRSV recirculation in sow herds.

Gene expression profile following an oral unsaturated fat load in abdominal obese subjects.

PURPOSE: Our aim was to evaluate the postprandial effect of an oral fat load test (OFLT) rich in unsaturated fatty acids on gene expression profile in peripheral blood mononuclear cells (PBMC) from subjects with abdominal obesity as an insulin resistance model and controls. METHODS: A total of 20 controls and 20 abdominal obese patients were studied. Metabolic parameters and oxidative stress markers were measured with standardized protocols. The whole gene expression at fasting state and after the OFLT (0, 4 and 8 h) was analysed using human HT-12-v4 expression beadchips, from Illumina. RESULTS: We found a significant decrease in plasma glucose, insulin and oxidative stress markers in abdominal obese patients and controls. We found beneficial metabolic postprandial gene expression in three genes: FKBP5, DDIT4 and DHRS9. Following an OFLT, the postprandial mRNA expression of FKBP5, and DDIT4 was downregulated while that of DHRS9 was overexpressed, both in nondiabetic normolipidemic subjects and in insulin-resistant subjects with abdominal obesity. CONCLUSIONS: Our results suggest that an OFLT rich in unsaturated fatty acids downregulates the expression of FKBP5, coding for the glucocorticoid receptor pathway, and that of DDIT4, involved in the oxidative stress response. These changes could favourably influence the insulin resistance and oxidative stress status in the postprandial state.

Topical Analgesia with Lidocaine Plus Diclofenac Decreases Pain in Benign Anorectal Surgery: Randomized, Double-blind, and Controlled Clinical Trial.

OBJECTIVE: The aim of this study is to evaluate the efficacy and safety of a topical formulation containing lidocaine plus diclofenac (CLIFE1) compared to lidocaine (CLIFE2), to decrease pain in benign anorectal surgery (BARS) to date not evaluated. More than 50% of patients undergoing BARS, especially hemorrhoidectomy, suffer from moderate and severe postoperative pain. This remains an unresolved problem that could be addressed with the new CLIFE1 topical treatment. METHODS: A multicenter, randomized double-blind, active-controlled parallel-group superiority trial, was conducted in two Spanish hospitals. Patients undergoing BARS (hemorrhoids, anal fistula and anal fissure) were randomized at the end of surgery at a 1:1 ratio to receive first dose either CLIFE1 (n = 60) or CLIFE2 (n = 60) anorectal topical treatment, and after every 12 h for the first three postoperative days and once a day from the fourth to sixth. The primary outcome was average of pain decrease after topical treatment, measured with visual analogue scale (VAS) by the patients themselves, the evening in the surgery day and four times daily for the first three postoperative days. RESULTS: The results of 120 patients included out of 150 selected undergoing BARS show a decrease in pain after CLIFE1 topical treatment (7.47 ± 13.09) greater than with CLIFE2 (4.38 ± 6.75), difference -3.21 95% CI (-5.75; -0.68), p = 0.008, decreasing significantly postoperative pain ( ≥ 9 mm, VAS) in 35% of patients undergoing benign anorectal surgery, compared to 18.33 % treated with lidocaine. CONCLUSIONS: The CLIFE1 topical treatment shows better analgesic efficacy than CLIFE2 in BARS.

Circulating tumor cells (CTCs) and cytokeratin 19 (CK19) mRNA as prognostic factors in heavily pretreated patients with metastatic breast cancer.

INTRODUCTION: Circulating tumor cell (CTC) count and cytokeratin 19 (CK19) mRNA expression have a prognostic value for patients with metastatic breast cancer (MBC), but their clinical utility remains controversial. We studied CTC count and CK19 mRNA expression in the peripheral blood samples from heavily pretreated patients with MBC and their correlations with prognosis and response to the subsequent line of therapy. METHODS: This prospective observational study included 67 consecutive patients with MBC who were on progression to systemic therapy, and criteria for a new line of systemic treatment were proposed outside a clinical trial. CTC counts and CK19 mRNA expression were measured by the CellSearch® and RT-PCR methods, respectively, before and after the first cycle of treatment. Progression-free survival (PFS) was defined as the time elapsed between the initiation of the treatment and either the date of clinical or radiological tumor progression or death from any cause or the last follow-up. Cox proportional hazards regression model was used to assess the univariate prognostic value of CTC and CK19 mRNA expression on PFS and Kaplan-Meier estimates. A multivariate Cox model was also used to additionally account for phenotype and visceral disease. RESULTS: The mean age was 60 (range 35-86) years, and the average number of previous treatments was 3 (range 1-10); 42 patients (62.6%) were ER+ and 38 patients (56.7%) had visceral disease. The median PFS rate was 8 months (95% CI: 3.7-8.2). Univariate analyses showed a significant effect of the initial value of CK19 mRNA expression (HR = 2.00; 95% CI: 1.05-3.8; p = 0.03) and for the second value of CTC (HR = 2.18; 95% CI: 1.22-3.9; p = 0.009) but did not reach statistical significance for the initial value of CTC and the second value of CK19 mRNA expression. The estimated PFS rates at 6 and 12 months were 75% and 31% for patients with a low initial value of CK19 mRNA expression and 36% and 10% for those with a high initial value of CK19 mRNA expression, respectively (p: 0.022). Further, the estimated PFS rates at 6 and 12 months were 86% and 65% for patients with a low second value of CTC and 76% and 47% for those with a high second value of CTC, respectively (p: 0.004). In the multivariate analysis adjusted for phenotype, visceral disease, and the last treatment performed, only the effect of the second value of CTC remained significant (HR = 2.7, p = 0.004). CONCLUSIONS: CK19 mRNA expression and CTC count appeared clinically meaningful in pretreated patients with MBC, even when adjusted for phenotype and visceral disease involvement. These results support the use of CK19 and CTC as relevant biomarkers for predicting clinical response in MBC.

Morphological, cytogenetic, and molecular characterization of Arachis kuhlmannii Krapov. & W.C. Greg. (Leguminosae).

Arachis kuhlmannii occurs in Mato Grosso and Mato Grosso do Sul States, Brazil. Its area of occurrence partially overlaps with that of other species in the Arachis section. Because of their morphological similarities, these species are often mistaken one for another. This study aimed the correct classification of available accessions as Arachis kuhlmannii, or other species, and the characterization of similarities among accessions and Arachis hypogaea by morphological, cytogenetic, and molecular marker analyses. Thirty-eight accessions were used. Principal component analysis was used for morphological characterization, root tips for mitotic metaphase analysis, and RAPD markers for molecular characterization. Cluster analysis discriminated accessions with the A genome from the B genome. Cluster analysis based on molecular markers discriminated natural populations in a manner that correlated with geographical areas of the collection. Arachis cardenasii and A. hypogaea were isolated from other A-genome accessions. Cytogenetic analyses confirmed the existence of diagnostic characteristics that distinguish species with the A genome from those with the B genome. Results suggest the need for a taxonomic review of some species in the Arachis section, as we could not discriminate as distinct species all of the accessions identified as A. kuhlmannii, A. helodes, and A. simpsonii by using morphological, molecular, and cytogenetic markers.

[Myths and evidence on the use of botulinum toxin: spasticity in adults and in children with cerebral palsy]. / Mitos y evidencias en el empleo de la toxina botulinica: espasticidad del adulto y del nintilde;o con paralisis cerebral.

INTRODUCTION: Spasticity is a medical problem with a high incidence that significantly impact on the quality of life of patients and their families. AIM: To analyze and to answer different questions about the use of botulinum toxin type A (BTA) in our clinical practice. DEVELOPMENT: A group of experts in neurology develop a list of topics related with the use of BTA. Two big groups were considered: spasticity in adults and in children with cerebral palsy. A literature search at PubMed for English, French, and Spanish language articles published up to June 2016 was performed. The manuscript was structured as a questionnaire that includes those questions that, according to the panel opinion, could generate more controversy or doubt. The initial draft was reviewed by the expert panel members to allow for modifications, and after subsequent revisions for achieving the highest degree of consensus, the final text was then validated. Different questions about diverse aspects of spasticity in adults, such as methods for evaluating spasticity, infiltration techniques, doses, number of infiltration points, etc. Regarding spasticity in children with cerebral palsy, the document included questions about minimum age of infiltration, methods of analgesia, etc. CONCLUSIONS: This review is a tool for continuous training for neurologist and rehabilitation specialist and residents of both specialties, about different specific areas of the management of BTA.

TITLE: Mitos y evidencias en el empleo de la toxina botulinica: espasticidad del adulto y del nintilde;o con paralisis cerebral.Introduccion. La espasticidad es un problema medico frecuente que impacta de forma significativa en la calidad de vida de los pacientes y sus familias. Objetivo. Analizar y dar respuesta a diferentes cuestiones en el uso de la toxina botulinica tipo A (TBA) en nuestra practica clinica habitual. Desarrollo. Un grupo de expertos en neurologia elaboro una lista de temas relacionados con el uso de la TBA. Se consideraron dos grandes bloques: espasticidad del adulto y del nintilde;o con paralisis cerebral. Se realizo una revision de la bibliografia que incluyo los diferentes articulos publicados en espantilde;ol, ingles y frances hasta junio de 2016. El documento se estructuro como un cuestionario que incluyo las preguntas que, segun el criterio del panel, podrian generar mayor controversia o duda. El borrador inicial del documento fue revisado por los miembros del panel y se realizaron las modificaciones necesarias hasta alcanzar el mayor grado de consenso. A continuacion, el texto final fue validado. Se incluyeron diferentes preguntas sobre diferentes aspectos de la espasticidad en adultos: evaluacion de la espasticidad, tecnicas de infiltracion, dosis, numero de puntos, etc. En cuanto a la espasticidad en los nintilde;os con paralisis cerebral, se analizaron preguntas como: edad minima de infiltracion, metodos de sedoanalgesia, etc. Conclusiones. Esta revision constituye una herramienta para neurologos, medicos rehabilitadores y residentes de ambas especialidades, dentro de diferentes ambitos especificos del manejo de la TBA.

Multimodal analgesia and regional anaesthesia. / Analgesia multimodal y anestesia regional.

Multimodal analgesia provides quality analgesia, with fewer side effects due to the use of combined analgesics or analgesic techniques. Regional anaesthesia plays a fundamental role in achieving this goal. The different techniques of regional anaesthesia that include both peripheral and central blocks in either a single dose or in continuous infusion help to modulate the nociceptive stimuli that access the central level. The emergence of the ultrasound as an effective system to perform regional anaesthesia techniques has allowed the development of new regional anaesthesia techniques that formerly could not be carried out since only neurostimulation or skin references were used. It is essential to take into account that even with effective blocking it is advisable to associate other drugs by other routes, in this way we will be able to reduce the required doses individually and attempt to achieve a synergistic, not purely additive, effect.

Immunohistochemical analysis of T-type calcium channels in acquired melanocytic naevi and melanoma.

BACKGROUND: Cutaneous malignant melanoma arises from transformed melanocytes de novo or from congenital or acquired melanocytic naevi. We have recently reported that T-type Ca2+ channels (TT-Cs) are upregulated in human melanoma and play an important role in cell proliferation. OBJECTIVES: To describe for the first time in formalin-fixed paraffin-embedded tissue the immunoexpression of TT-Cs in biopsies of normal skin, acquired melanocytic naevi and melanoma, in order to evaluate their role in melanomagenesis and/or tumour progression, their utility as prognostic markers and their possible use in targeted therapies. METHODS: Tissue samples from normal skin, melanocytic naevi and melanoma were subjected to immunohistochemistry for two TT-Cs (Cav3.1, Cav3.2); markers of proliferation (Ki67), the cell cycle (cyclin D1), hypoxia (Glut1), vascularization (CD31) and autophagy (LC3); BRAF V600E mutation (VE1) and phosphatase and tensin homologue (PTEN). Immunostaining was evaluated by histoscore. In silico analysis was used to assess the prognostic value of TT-C overexpression. RESULTS: TT-C immunoexpression increased gradually from normal skin to common naevi, dysplastic naevi and melanoma samples, but with differences in the distribution of both isoforms. Particularly, Cav3.2 expression was significantly higher in metastatic melanoma than in primary melanoma. Statistical correlation showed a linear interaction between PTEN loss/BRAF V600E/Cav3.1/LC3/ Ki67/cyclin D1/Cav3.2/Glut1. Disease-free survival (DFS) and overall survival correlated inversely with overexpression of Cav3.2. DFS also correlated inversely with overexpression of Cav3.1. CONCLUSIONS: TT-C immunoexpression on melanocytic neoplasms is consistent with our previous in vitro studies and appears to be related to tumour progression. TT-C upregulation can be considered as a prognostic marker using The Cancer Genome Atlas database. The high expression of Cav3.2 in metastatic melanoma encourages the investigation of the use of TT-C blockers in targeted therapies.

Genetic diversity of the forage peanut in the Jequitinhonha, São Francisco, and Paranã River valleys of Brazil.

Arachis pintoi and A. repens are legumes with a high forage value that are used to feed ruminants in consortium systems. Not only do they increase the persistence and quality of pastures, they are also used for ornamental and green cover. The objective of this study was to analyze microsatellite markers in order to access the genetic diversity of 65 forage peanut germplasm accessions in the section Caulorrhizae of the genus Arachis in the Jequitinhonha, São Francisco and Paranã River valleys of Brazil. Fifty-seven accessions of A. pintoi and eight of A. repens were analyzed using 17 microsatellites, and the observed heterozygosity (HO), expected heterozygosity (HE), number of alleles per locus, discriminatory power, and polymorphism information content were all estimated. Ten loci (58.8%) were polymorphic, and 125 alleles were found in total. The HE ranged from 0.30 to 0.94, and HO values ranged from 0.03 to 0.88. By using Bayesian analysis, the accessions were genetically differentiated into three gene pools. Neither the unweighted pair group method with arithmetic mean nor a neighbor-joining analysis clustered samples into species, origin, or collection area. These results reveal a very weak genetic structure that does not form defined clusters, and that there is a high degree of similarity between the two species.

Characteristics of particulate and non-particulate corticosteroids. Indications for their use in chronic pain treatments. / Características de los corticoides particulados y no particulados. Condicionantes para su uso en el tratamiento del dolor crónico.

Corticosteroids been used frequently in pain treatments since the middle of last century (1952). Due to a review of the complications as a result of their application in epidural injections, the United States of America Food and Drug Administration (FDA) issued an «alert controversy¼ requesting that a warning label should be added to injectable corticosteroids, where risks must be described (loss of sight, brain damage, paralysis and death) when administering by this route. It must be mentioned that there are different types of corticosteroids with diverse characteristics, which as a result, may produce different side-effects. Due to the aforementioned developments, the controversies that have arisen, and the lack of well-conducted studies on the use of steroids in epidural injections, we must begin by reviewing their indications in different pain conditions.

Sacroiliac joint pain: Prospective, randomised, experimental and comparative study of thermal radiofrequency with sacroiliac joint block.

OBJECTIVE: To compare the analgesic effects between the blockade and bipolar thermal radiofrequency in the treatment of sacroiliac joint pain. METHOD: Prospective, randomised and experimental study conducted on 60 patients selected in the two hospitals over a period of nine months, who had intense sacroiliac joint pain (Visual Analogue Scale [VAS]>6) that lasted more than 3 months. Patients were randomised into three groups (n=20): Group A (two intra-articular sacroiliac injections of local anaesthetic/corticosteroid guided by ultrasound in 7 days). Group B: conventional bipolar radiofrequency "palisade". Target points were the lateral branch nerves of S1, S2, and S3, distance needles 1cm. Group C: modified bipolar radiofrequency "palisade" (needle distance >1cm). Patients were evaluated at one month, three months, and one year. Demographic data, VAS reduction, and side effects of the techniques were assessed. RESULTS: One month after the treatment, pain reduction was >50% in the three groups P<.001. Three and 12 months after the technique, the patients of the group A did not have a significant reduction in pain. At 3 months, almost 50% patients of the group B referred to improvement of the pain (P=.03), and <25% at 12 months, and those results were statistically significant (P=.01) compared to the baseline. Group C showed an improvement of 50% at 3 and 12 months (P<.001). All patients completed the study. CONCLUSIONS: Bipolar radiofrequency "palisade", especially when the distance between the needles was increased, was more effective and lasted longer, compared to join block and steroids, in relieving pain sacroiliac joint.

Role of primary care in the follow-up of patients with obstructive sleep apnoea undergoing CPAP treatment: a randomised controlled trial.

OBJECTIVE: To evaluate whether follow-up of patients with obstructive sleep apnoea (OSA) undergoing CPAP treatment could be performed in primary care (PC) settings. DESIGN: Non-inferiority, randomised, prospective controlled study. SETTINGS: Sleep unit (SU) at the University Hospital and in 8 PC units in Lleida, Spain. PARTICIPANTS: Patients with OSA were randomised to be followed up at the SU or PC units over a 6-month period. MAIN OUTCOMES MEASURED: The primary outcome was CPAP compliance at 6 months. The secondary outcomes were Epworth Sleep Scale (ESS) score, EuroQoL, patient satisfaction, body mass index (BMI), blood pressure and cost-effectiveness. RESULTS: We included 101 patients in PC ((mean±SD) apnoea-hypopnoea index (AHI) 50.8±22.9/h, age 56.2±11 years, 74% male) and 109 in the SU (AHI 51.4±24.4/h, age 55.8±11 years, 77% male)). The CPAP compliance was (mean (95% CI) 4.94 (4.47 to 5.5) vs 5.23 (4.79 to 5.66) h, p=0.18) in PC and SU groups, respectively. In the SU group, there were greater improvements in ESS scores (mean change 1.79, 95% CI +0.05 to +3.53, p=0.04) and patient satisfaction (-1.49, 95% CI -2.22 to -0.76); there was a significant mean difference in BMI between the groups (0.57, 95% CI +0.01 to +1.13, p=0.04). In the PC setting, there was a cost saving of 60%, with similar effectiveness, as well as a decrease in systolic blood pressure (-5.32; 95% CI -10.91 to +0.28, p=0.06). CONCLUSIONS: For patients with OSA, treatment provided in a PC setting did not result in worse CPAP compliance compared with a specialist model and was shown to be a cost-effective alternative. TRIAL REGISTRATION NUMBER: Clinical Trials NCT01918449.

Similar worldwide patterns in the sex pheromone signal and response in the oriental fruit moth, Grapholita molesta (Lepidoptera: Tortricidae).

The response of Grapholita molesta (Busck) males to three-component sex pheromone blends containing a 100% ratio of the major sex pheromone component, (Z)-8-dodecenyl acetate and a 10% ratio of (Z)-8-dodecenol, but with varying ratios of (E)-8-dodecenyl acetate (0.4, 5.4, 10.4, 30.4, and 100.1% E-blends) was tested with populations in eight stone and pome fruit orchards in Europe, Asia, and North and South America. Traps baited with the 5.4% E-blend caught significantly more males than traps with any other blend with all populations. Significantly more males were caught in traps baited with the 10.4% E-blend than in traps with the remaining blends, except with the 0.4% E-blend in Turkey. Significant differences in male moth catches occurred between the other blends with the 0.4>30.4% E-blend, and the 30.4>100.1% E-blend. Male moth catches with the 100.1% E-blend only differed from the hexane control in Chile. No apparent differences were noted to these blends in populations collected from pome or stone fruits. Flight tunnel assays to synthetic blends with a subset of populations were similar to the field results, but the breadth of the most attractive E-blends was wider. Flight tunnel assays also demonstrated a high level of male-female cross-attraction among field-collected populations. Female gland extracts from field-collected populations did not show any significant variation in their three-component blends. The only exceptions in these assays were that long-term laboratory populations were less responsive and attractive, and produced different blend ratios of the two minor components than recently collected field populations.

Crossability of Arachis valida and B genome Arachis species.

The peanut (Arachis hypogaea) is an important food crop in much of the tropical and semi-tropical parts of the world. The peanut is an allotetraploid with an AABB genome formula derived from diploids A. duranensis (A genome) and A. ipaënsis (B genome). The success of an introgression program that aims to improve cultivated varieties of the peanut depends on whether the chosen B genome species is homologous with the B genome of the peanut. While not directly involved in the origin of the peanut to the best of our knowledge, Arachis valida is a B genome species that could potentially be a bridge species or a source of new and different alleles, because of its resistance to diseases and pests. In this study, we investigated the crossability of A. valida with five other B genome species of section Arachis. Eight cross-combinations were made with A. valida and A. gregoryi, A. ipaënsis, A. magna, A. valida, and A. williamsii. Two hundred and forty pollinations were made yielding 61 fruit segments, 61 seeds, one abortion, and 24 hybrid plants. An analysis of the morphological characteristics and pollen viability confirmed that the plants were hybrids. Our results indicated that higher pollen viability of hybrid plants corresponded with higher affinity between parent plants used in crossings. This conclusion corroborates much of previous research carried out by many other authors in the past.

Impact of obstructive sleep apnea on the 24-h metabolic hormone profile.

OBJECTIVE: Obstructive sleep apnea (OSA) has been associated with metabolic disorders. Sleep-disordered breathing could generate an altered rhythm in the expression of metabolic hormones, which could predispose to metabolic disorders. The aim of this study was to evaluate the effect of sleep apnea on diurnal variations in metabolic hormones. METHODS: Thirty-seven male, newly diagnosed, patients with OSA with an apnea-hypopnea index (AHI) > or = 20/h and 11 male controls (AHI <10/h) matched for body mass index (±3 kg/m2) were included. Six different samples were obtained from each subject during a period of 24h. Levels of the metabolic hormones ghrelin, leptin, resistin, and adiponectin were measured in plasma by immunoassay. RESULTS: Patients with OSA (AHI (mean±SD) 46±26/h) were older than the controls (42±9 vs. 33±9 years, P=0.01). Differences in metabolic hormones between groups did not reach statistical significance at any point in the evaluation. No significant differences were observed in the area under the curve for any of the hormones analysed. Likewise, we did not detect diurnal variations in metabolic hormones. CONCLUSIONS: The results of this study indicate that the day-night variations in the levels of several metabolic hormones are not influenced by the presence of sleep apnea.

Complete asynapsis resulting in 2n pollen formation in Paspalum jesuiticum Parodi (Poaceae).

Cytological investigation revealed complete asynapsis during microsporogenesis in 2 wild accessions of Paspalum jesuiticum collected in distinct Brazilian regions. Both accessions were hexaploid (2n = 6x = 60) and 60 univalents could be counted at diakinesis. In this phase, the majority of meiocytes exhibited univalents with both chromatids. After alignment at the metaphase plate, the chromatids segregated to the poles. Only 1 meiotic division (equational) occurred, and after cytokinesis, a dyad with 2n microspores was formed. The genetic constitution of the 2n gametes was equivalent to that of first division restitution (FDR). Since recombination did not occur, 100% transmission of parental heterozygosity could be expected from the FDR 2n gametes. The meiotic behavior of both accessions suggested that they resulted from a recent natural hybridization event. The potential use of the 2n gametes in Paspalum breeding programs has been discussed.

Microsporogenesis in Paspalum conspersum Schrad. (Virgata group) with different ploidy levels.

Knowledge about the cytology and reproductive behavior of a species is indispensable for hybridization programs. This is especially true for species belonging to the genus Paspalum, among which apomixis and a wide range of ploidy levels are frequently found. Paspalum conspersum Schrad. is a robust and warm-season perennial bunchgrass native to South America. Previous studies have indicated that both tetraploid and hexaploid races exist in this species; however, only information related to tetraploids has been applied to another taxon. In this study, a cytological investigation in two Brazilian accessions collected in different regions revealed tetraploidy in the accession BRA-012823 (2n = 4x = 40), with chromosome pairing in bivalents and normal meiosis and tetrad formation, and pentaploidy (2n = 5x = 50) in the accession BRA-022748, which presented total asynapsis. In this latter accession, 50 univalents could be scored at diakinesis. After alignment at the metaphase plate, sister chromatids segregated to the poles. Only one meiotic division (equational) occurred, and after cytokinesis, 100% of the dyads that formed had 2n microspores. The meiotic behavior during microsporogenesis, which showed 10 delayed univalents to reach the metaphase plate, suggests that this accession is a recent natural hybrid constituted by a parental genome with 40 chromosomes and another with 10 chromosomes. The potential usage of these accessions in Paspalum breeding has been discussed.

Peroxiredoxin 2 specifically regulates the oxidative and metabolic stress response of human metastatic breast cancer cells in lungs.

Little is known about metastatic pathways that are specific to the lung rather than other organs. We previously showed that antioxidant proteins such as peroxiredoxins were specifically upregulated in lung metastatic breast cancer cells. We hypothesize that cancer cells that live under aerobic conditions, as might be the case in lungs, protect themselves against the damage caused by reactive oxygen species (ROS). To examine this hypothesis, we studied the role of peroxiredoxin-2 (PRDX2) in lung vs bone metastasis formation. A metastatic variant of MDA-MB-435 breast cancer cells that specifically metastasize to lungs (435-L3) was transduced with short hairpin RNAs to specifically silence PRDX2. Conversely, a bone metastatic variant of MDA-MB-231 cells (BO2) was stably transfected to overexpress PRDX2. The 435-L3 cells silenced for PRDX2 were significantly more sensitive to H(2)O(2)-induced oxidative stress than the parental and scrambled transfected cells. BO2/PRDX2 cells produced less ROS than BO2/green fluorescent protein control cells under oxidative stress. Moreover, PRDX2 knockdown inhibited the growth of 435-L3 cells in the lungs, whereas lymph node metastasis remained unaffected. In contrast, PRDX2 overexpression in bone metastatic BO2 breast cancer cells led to drastic inhibition of the skeletal tumor burden and reduction of bone destruction. Furthermore, PRDX2 expression in breast cancer cells was associated with a glucose-dependent phenotype, different from bone metastatic cells. Overall, our results strongly suggest that PRDX2 is a targetable 'metabolic adaptor' driver protein implicated in the selective growth of metastatic cells in the lungs by protecting them against oxidative stress.

Cuticular hydrocarbons discriminate cryptic Macrolophus species (Hemiptera: Miridae).

Macrolophus pygmaeus is commercially employed in the biological control of greenhouse and field vegetable pests. It is morphologically undistinguishable from the cryptic species M. melanotoma, and this interferes with the evaluation of the biological control activity of M. pygmaeus. We analysed the potential of cuticular hydrocarbon composition as a method to discriminate the two Macrolophus species. A third species, M. costalis, which is different from the other two species by having a dark spot at the tip of the scutellum, served as a control. Sex, diet and species, all had significant effects in the cuticular hydrocarbon profiles, but the variability associated to sex or diet was smaller than among species. Discriminant quadratic analysis of cuticular hydrocarbons confirmed the results of previous molecular genetic studies and showed, using cross-validation methods, that M. pygmaeus can be discriminated from M. costalis and M. melanotoma with prediction errors of 6.75% and 0%, respectively. Therefore, cuticular hydrocarbons can be used to separate M. pygmaeus from M. melanotoma reliably.