Prognostic Factors for Mortality in Hepatocellular Carcinoma at Diagnosis: Development of a Predictive Model Using Artificial Intelligence

BACKGROUND

Hepatocellular carcinoma (HCC) accounts for 75% of primary liver tumors. Controlling risk factors associated with its development and implementing screenings in risk populations does not seem sufficient to improve the prognosis of these patients at diagnosis. The development of a predictive prognostic model for mortality at the diagnosis of HCC is proposed.

METHODS

In this retrospective multicenter study, the analysis of data from 191 HCC patients was conducted using machine learning (ML) techniques to analyze the prognostic factors of mortality that are significant at the time of diagnosis. Clinical and analytical data of interest in patients with HCC were gathered.

RESULTS

Meeting Milan criteria, Barcelona Clinic Liver Cancer (BCLC) classification and albumin levels were the variables with the greatest impact on the prognosis of HCC patients. The ML algorithm that achieved the best results was random forest (RF).

CONCLUSIONS

The development of a predictive prognostic model at the diagnosis is a valuable tool for patients with HCC and for application in clinical practice. RF is useful and reliable in the analysis of prognostic factors in the diagnosis of HCC. The search for new prognostic factors is still necessary in patients with HCC.

Approaching Personalized Medicine: The Use of Machine Learning to Determine Predictors of Mortality in a Population with SARS-CoV-2 Infection

The COVID-19 pandemic demonstrated the need to develop strategies to control a new viral infection. However, the different characteristics of the health system and population of each country and hospital would require the implementation of self-systems adapted to their characteristics. The objective of this work was to determine predictors that should identify the most severe patients with COVID-19 infection. Given the poor situation of the hospitals in the first wave, the analysis of the data from that period with an accurate and fast technique can be an important contribution. In this regard, machine learning is able to objectively analyze data in hourly sets and is used in many fields. This study included 291 patients admitted to a hospital in Spain during the first three months of the pandemic. After screening seventy-one features with machine learning methods, the variables with the greatest influence on predicting mortality in this population were lymphocyte count, urea, FiO2, potassium, and serum pH. The XGB method achieved the highest accuracy, with a precision of >95%. Our study shows that the machine learning-based system can identify patterns and, thus, create a tool to help hospitals classify patients according to their severity of illness in order to optimize admission.

Systemic Lupus Erythematosus: How Machine Learning Can Help Distinguish between Infections and Flares

Systemic Lupus Erythematosus (SLE) is a multifaceted autoimmune ailment that impacts multiple bodily systems and manifests with varied clinical manifestations. Early detection is considered the most effective way to save patients' lives, but detecting severe SLE activity in its early stages is proving to be a formidable challenge. Consequently, this work advocates the use of Machine Learning (ML) algorithms for the diagnosis of SLE flares in the context of infections. In the pursuit of this research, the Random Forest (RF) method has been employed due to its performance attributes. With RF, our objective is to uncover patterns within the patient data. Multiple ML techniques have been scrutinized within this investigation. The proposed system exhibited around a 7.49% enhancement in accuracy when compared to k-Nearest Neighbors (KNN) algorithm. In contrast, the Support Vector Machine (SVM), Binary Linear Discriminant Analysis (BLDA), Decision Trees (DT) and Linear Regression (LR) methods demonstrated inferior performance, with respective values around 81%, 78%, 84% and 69%. It is noteworthy that the proposed method displayed a superior area under the curve (AUC) and balanced accuracy (both around 94%) in comparison to other ML approaches. These outcomes underscore the feasibility of crafting an automated diagnostic support method for SLE patients grounded in ML systems.

Predictive Model for Mortality in Severe COVID-19 Patients across the Six Pandemic Waves

The impact of SARS-CoV-2 infection remains substantial on a global scale, despite widespread vaccination efforts, early therapeutic interventions, and an enhanced understanding of the disease's underlying mechanisms. At the same time, a significant number of patients continue to develop severe COVID-19, necessitating admission to intensive care units (ICUs). This study aimed to provide evidence concerning the most influential predictors of mortality among critically ill patients with severe COVID-19, employing machine learning (ML) techniques. To accomplish this, we conducted a retrospective multicenter investigation involving 684 patients with severe COVID-19, spanning from 1 June 2020 to 31 March 2023, wherein we scrutinized sociodemographic, clinical, and analytical data. These data were extracted from electronic health records. Out of the six supervised ML methods scrutinized, the extreme gradient boosting (XGB) method exhibited the highest balanced accuracy at 96.61%. The variables that exerted the greatest influence on mortality prediction encompassed ferritin, fibrinogen, D-dimer, platelet count, C-reactive protein (CRP), prothrombin time (PT), invasive mechanical ventilation (IMV), PaFi (PaO2/FiO2), lactate dehydrogenase (LDH), lymphocyte levels, activated partial thromboplastin time (aPTT), body mass index (BMI), creatinine, and age. These findings underscore XGB as a robust candidate for accurately classifying patients with COVID-19.

Personalized Risk Assessment of Hepatic Fibrosis after Cholecystectomy in Metabolic-Associated Steatotic Liver Disease: A Machine Learning Approach

Metabolic Associated Fatty Liver Disease (MASLD) is a condition that is often present in patients with a history of cholecystectomy. This is because both situations share interconnected metabolic pathways. This study aimed to establish a predictive model that allows for the identification of patients at risk of developing hepatic fibrosis following this surgery, with potential implications for surgical decision-making. A retrospective cross-sectional analysis was conducted in four hospitals using a database of 211 patients with MASLD who underwent cholecystectomy. MASLD diagnosis was established through liver biopsy or FibroScan, and non-invasive test scores were included for analysis. Various Machine Learning (ML) methods were employed, with the Adaptive Boosting (Adaboost) system selected to build the predictive model. Platelet level emerged as the most crucial variable in the predictive model, followed by dyslipidemia and type-2 diabetes mellitus. FIB-4 score proved to be the most reliable non-invasive test. The Adaboost algorithm improved the results compared to the other methods, excelling in both accuracy and area under the curve (AUC). Moreover, this system holds promise for implementation in hospitals as a valuable diagnostic support tool. In conclusion, platelet level (<150,000/dL), dyslipidemia, and type-2 diabetes mellitus were identified as primary risk factors for liver fibrosis in MASLD patients following cholecystectomy. FIB-4 score is recommended for decision-making, particularly when the indication for surgery is uncertain. This predictive model offers valuable insights into risk stratification and personalized patient management in post-cholecystectomy MASLD cases.

Machine learning, a new tool for the detection of immunodeficiency patterns in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease that affects several organs and causes variable clinical symptoms. Early diagnosis is currently the most effective way to save the lives of patients with SLE. But it is very difficult to detect in the early stages of the disease. Because of this, this study proposes a machine learning system to help diagnose patients with SLE. To carry out the research, the extreme gradient boosting method has been implemented due to its performance characteristics, as it allows high performance, scalability, accuracy, and low computational load. From this method we try to recognize patterns in the data obtained from patients, which allow the classification of SLE patients with high accuracy and differentiate these patients from controls. Several machine learning methods have been analyzed in this study. The proposed method achieves a higher prediction value of patients who may suffer from SLE than the rest of the compared systems. The proposed algorithm achieved an improvement in accuracy of 4.49% over k-Nearest Neighbors. As for the Support Vector Machine and Gaussian Naive Bayes (GNB) methods, they achieved a lower performance than the proposed one, reaching values of 83% and 81%, respectively. It should be noted that the proposed system showed a higher area under the curve (90%) and a balanced accuracy (90%) than the other machine learning methods. This study shows the usefulness of ML techniques for identifying and predicting SLE patients. These results demonstrate the possibility of developing automatic diagnostic support systems for SLE patients based on machine learning techniques.

A Machine Learning-Based Method for Detecting Liver Fibrosis

Cholecystectomy and Metabolic-associated steatotic liver disease (MASLD) are prevalent conditions in gastroenterology, frequently co-occurring in clinical practice. Cholecystectomy has been shown to have metabolic consequences, sharing similar pathological mechanisms with MASLD. A database of MASLD patients who underwent cholecystectomy was analysed. This study aimed to develop a tool to identify the risk of liver fibrosis after cholecystectomy. For this purpose, the extreme gradient boosting (XGB) algorithm was used to construct an effective predictive model. The factors associated with a better predictive method were platelet level, followed by dyslipidaemia and type-2 diabetes (T2DM). Compared to other ML methods, our proposed method, XGB, achieved higher accuracy values. The XGB method had the highest balanced accuracy (93.16%). XGB outperformed KNN in accuracy (93.16% vs. 84.45%) and AUC (0.92 vs. 0.84). These results demonstrate that the proposed XGB method can be used as an automatic diagnostic aid for MASLD patients based on machine-learning techniques.

A Machine Learning Method to Identify the Risk Factors for Liver Fibrosis Progression in Nonalcoholic Steatohepatitis

AIM

Nonalcoholic fatty liver disease (NAFLD) is a silent epidemy that has become the most common chronic liver disease worldwide. Nonalcoholic steatohepatitis (NASH) is an advanced stage of NAFLD, which is linked to a high risk of cirrhosis and hepatocellular carcinoma. The aim of this study is to develop a predictive model to identify the main risk factors associated with the progression of hepatic fibrosis in patients with NASH.

METHODS

A database from a multicenter retrospective cross-sectional study was analyzed. A total of 215 patients with NASH biopsy-proven diagnosed were collected. NAFLD Activity Score and Kleiner scoring system were used to diagnose and staging these patients. Noninvasive tests (NITs) scores were added to identify which one were more reliable for follow-up and to avoid biopsy. For analysis, different Machine Learning methods were implemented, being the eXtreme Gradient Booster (XGB) system the proposed algorithm to develop the predictive model.

RESULTS

The most important variable in this predictive model was High-density lipoprotein (HDL) cholesterol, followed by systemic arterial hypertension and triglycerides (TG). NAFLD Fibrosis Score (NFS) was the most reliable NIT. As for the proposed method, XGB obtained higher results than the second method, K-Nearest Neighbors, in terms of accuracy (95.05 vs. 90.42) and Area Under the Curve (0.95 vs. 0.91).

CONCLUSIONS

HDL cholesterol, systemic arterial hypertension, and TG were the most important risk factors for liver fibrosis progression in NASH patients. NFS is recommended for monitoring and decision making.

Method for Classifying Schizophrenia Patients Based on Machine Learning

Schizophrenia is a chronic and severe mental disorder that affects individuals in various ways, particularly in their ability to perceive, process, and respond to stimuli. This condition has a significant impact on a considerable number of individuals. Consequently, the study, analysis, and characterization of this pathology are of paramount importance. Electroencephalography (EEG) is frequently utilized in the diagnostic assessment of various brain disorders due to its non-intrusiveness, excellent resolution and ease of placement. However, the manual analysis of electroencephalogram (EEG) recordings can be a complex and time-consuming task for healthcare professionals. Therefore, the automated analysis of EEG recordings can help alleviate the burden on doctors and provide valuable insights to support clinical diagnosis. Many studies are working along these lines. In this research paper, the authors propose a machine learning (ML) method based on the eXtreme Gradient Boosting (XGB) algorithm for analyzing EEG signals. The study compares the performance of the proposed XGB-based approach with four other supervised ML systems. According to the results, the proposed XGB-based method demonstrates superior performance, with an AUC value of 0.94 and an accuracy value of 0.94, surpassing the other compared methods. The implemented system exhibits high accuracy and robustness in accurately classifying schizophrenia patients based on EEG recordings. This method holds the potential to be implemented as a valuable complementary tool for clinical use in hospitals, supporting clinicians in their clinical diagnosis of schizophrenia.

The anti-snake activity of Nectandra angustifolia flavonoids on phospholipase A2: In vitro and in silico evaluation

ETHNOPHARMACOLOGICAL RELEVANCE

Lauraceae family includes Nectandra angustifolia a species widely used in the folk medicine of South America against various maladies. It is commonly used to treat different types of processes like inflammation, pain, and snakebites. Snakes of the Bothrops genus are responsible for about 97% of the ophidic accidents in northeastern Argentina.

AIM OF THE STUDY

To evaluate the anti-snake activity of the phytochemicals present in N. angustifolia extracts, identify the compounds, and evaluate their inhibitory effect on phospholipase A2 (PLA2) with in vitro and in silico assays.

METHODS

Seasonal variations in the alexiteric potential of aqueous, ethanolic and hexanic extracts were evaluated by inhibition of coagulant, haemolytic, and cytotoxic effects of B. diporus venom. The chemical identity of an enriched fraction obtained by bio-guided fractioning was established by UPLC-MS/MS analysis. Molecular docking studies were carried out to investigate the binding mechanisms of the identified compounds to PLA2 enzyme from snake venom.

RESULTS

All the extracts inhibited venom coagulant activity. However, spring ethanolic extract achieved 100% inhibition of haemolytic activity. Bio-guide fractioning led to an enriched fraction (F4) with the highest haemolytic inhibition. Five flavonoids were identified in this fraction; molecular docking and Molecular Dynamics (MD) simulations indicated the binding mechanisms of the identified compounds. The carbohydrates present in some of the compounds had a critical effect on the interaction with PLA2.

CONCLUSION

This study shows, for the first time, which compounds are responsible for the anti-snake activity in Nectandra angustifolia based on in vitro and in silico assays. The results obtained in this work support the traditional use of this species as anti-snake in folk medicine.

Oral manifestations associated with inflammatory bowel disease and early endoscopic findings in patients with spondyloarthritis

BACKGROUND AND AIMS

Spondyloarthritis (SpA) is a group of autoinflammatory disorders, of which the primary extra-articular manifestation is inflammatory bowel disease (IBD). The oral cavity being a part of gastrointestinal tract, is significantly compromised in IBD, and in many cases, it is the first site of clinical manifestations of IBD. This study aimed to identify changes in the oral mucosa associated with the onset of IBD and their association with endoscopic/histological findings.

MATERIALS AND METHODS

The study assessed 80 patients with SpA and 52 healthy controls. Oral, rheumatological, and gastroenterological assessments were performed. The ileocolonoscopy was performed via digital magnification chromoendoscopy. The statistical analysis consisted of Chi-square, Fisher's exact, and multiple correspondence discriminant analysis tests.

RESULTS

From the disease cohort, 63.0% patients showed oral lesions (p = 0.050). These manifestations ranged from gingivitis (55.0%, p = 0.001), aphthous stomatitis (3.8%, p = 0.091), angular cheilitis (2.6%, p = 0.200), and perioral erythema with scaling (1.3%, p = 0.300). All patients who presented with alterations in colonic mucosa also had oral lesions associated with IBD (p = 0.039), specifically gingivitis/aphthous stomatitis (p = 0.029).

CONCLUSION

The patients with SpA without IBD present significant oral signs and symptoms. Gingivitis seems to be the most relevant because of its associations with early endoscopic and histological findings.

CLINICAL RELEVANCE

An integral approach to the diagnostic tests that includes evaluations of oral, rheumatological and gastroenterological tissues may favor timely attention and improve patients' quality of life.

Application of Machine Learning in Hospitalized Patients with Severe COVID-19 Treated with Tocilizumab

Among the IL-6 inhibitors, tocilizumab is the most widely used therapeutic option in patients with SARS-CoV-2-associated severe respiratory failure (SRF). The aim of our study was to provide evidence on predictors of poor outcome in patients with COVID-19 treated with tocilizumab, using machine learning (ML) techniques. We conducted a retrospective study, analyzing the clinical, laboratory and sociodemographic data of patients admitted for severe COVID-19 with SRF, treated with tocilizumab. The extreme gradient boost (XGB) method had the highest balanced accuracy (93.16%). The factors associated with a worse outcome of tocilizumab use in terms of mortality were: baseline situation at the start of tocilizumab treatment requiring invasive mechanical ventilation (IMV), elevated ferritin, lactate dehydrogenase (LDH) and glutamate-pyruvate transaminase (GPT), lymphopenia, and low PaFi [ratio between arterial oxygen pressure and inspired oxygen fraction (PaO₂/FiO₂)] values. The factors associated with a worse outcome of tocilizumab use in terms of hospital stay were: baseline situation at the start of tocilizumab treatment requiring IMV or supplemental oxygen, elevated levels of ferritin, glutamate-oxaloacetate transaminase (GOT), GPT, C-reactive protein (CRP), LDH, lymphopenia, and low PaFi values. In our study focused on patients with severe COVID-19 treated with tocilizumab, the factors that were weighted most strongly in predicting worse clinical outcome were baseline status at the start of tocilizumab treatment requiring IMV and hyperferritinemia.

[Update on the effectiveness and evidence of antenatal perineal massage]

The impact and morbidity generated by perineal trauma during vaginal delivery justifies the need to find strategies to minimize it. Antenatal perineal massage (APM) is proposed as a technique that increases the elasticity of the perineum and that could reduce damage to the pelvic floor. This review set out to discover the effectiveness and the scientific evidence that supports this procedure. The Medline, Cochrane, Tripdatabase and Cuiden databases for the last six years were consulted, in Spanish and English. Ten studies with different levels of evidence were found. All of them favoured the use of this technique. Although further research is needed, evidence currently available suggests that the use of APM in late pregnancy could be an effective and safe procedure to reduce perineal trauma in childbirth, especially in primiparous women, and postpartum pain in multi-parous women.

Anti-inflammatory activity of Nectandra angustifolia (Laurel Amarillo) ethanolic extract

ETHNOPHARMACOLOGICAL RELEVANCE

Nectandra angustifolia belongs to the Lauraceae family and it is widely known in phytomedicine by local inhabitants of South America against various maladies. It is popularly used for the treatment of different types of inflammatory processes, like rheumatism, arthritis and its associated pain.

AIM OF THE STUDY

To characterize the phytochemicals in an ethanolic extract of Nectandra angustifolia and to evaluate the total antioxidant content and its anti-inflammatory effect with multiparametric analyses through in vitro assays and an in vivo model.

METHODS

Leaves and stems of Nectandra angustifolia were air-dried and an ethanolic extract (NaE) was further obtained. Total phenolic, flavonoid and tannin content were determined and the antioxidant activity was addressed by DPPH and FRAP assays. NaE was first analyzed by HPLC and then two tests were carried out as screening assays for anti-inflammatory activities: red blood cell membrane stabilization and protein denaturation. The non-cytotoxic concentration of NaE was determined for in vitro biological assays using RAW 264.7 (murine macrophages) cell cultures through cell counting with Trypan-blue and XTT assay. Subsequently, the cell cycle of RAW 264.7 cells exposed for 24 h to NaE was analyzed. Additionally, the anti-inflammatory capacity of NaE was evaluated by RT-qPCR of pro-inflammatory cytokines. Furthermore, NF-κB translocation was observed by confocal microscopy at different times. Finally, formalin-induced mice paw inflammation was used as an in vivo model.

RESULTS

The chromatographic profile of NaE showed peaks compatible with flavonoids content. NaE exhibited better membrane stabilization effect on HRBC and protection of BSA denaturation than the standard drug (diclofenac). NaE diminished mRNA levels of pro-inflammatory cytokines when added 1-h prior LPS stimulation. Moreover, NaE prevented the translocation of NF-κB to the nucleus and in formalin-induced mice paw inflammation, reduced the edema and the stimulus of inflammatory phase.

CONCLUSION

This study shows for the first time, that Nectandra angustifolia ethanolic extract has a high content of flavonoids and that possess antioxidant and anti-inflammatory biological properties as demonstrated by multiparametric analyses from in vitro assays and an in vivo model of inflammation.

Fusarium cerealis causing Fusarium head blight of durum wheat and its associated mycotoxins

Fusarium Head Blight (FHB) is a very important fungal disease that affects small grain cereals worldwide. This disease not only causes yield loses but also crops contamination with mycotoxins such as deoxynivalenol (DON) and nivalenol (NIV). Species within the Fusarium graminearum species complex have been described as the main causal agents of this disease, however lately there have been few reports of Fusarium cerealis causing the disease in wheat and barley in different parts of the world. This study evaluated the aggressiveness of F. cerealis to durum wheat cultivars and also mycotoxin production in planta. Moreover, the mycotoxin profile of F. cerealis strains was characterized molecularly and chemically. All durum wheat cultivars showed typical FHB symptoms but the disease severity varied among them in levels up to 66%. In addition, seventeen different compounds were detected in the infected heads including DON, NIV and nivalenol-3-β-d-glucose (NIV3G). NIV was detected in all cultivars and was the most produced mycotoxin with levels ranging from 1.04 to 6.8 mg/kg. On the other hand, the molecular analysis of F. cerealis strains showed that all of them possessed NIV genotype while the chemical assessment showed that the strains were able to produce not only this toxin in vitro but also DON, zearalenone and other twenty-one secondary metabolites. The increasing incidence of F. cerealis and the possible contamination of crops with the mycotoxins that it produces are of great concern for food security and world cereal trade since it has been reported that NIV is more toxic for humans and animals than DON.

Effect of erythropoietin on mercury-induced nephrotoxicity: Role of membrane transporters

Mercury is a widespread pollutant. Mercuric ions uptake into tubular cells is supported by the Organic anion transporter 1 (Oat1) and 3 (Oat3) and its elimination into urine is through the Multidrug resistance-associated protein 2 (Mrp2). We investigated the effect of recombinant human erythropoietin (Epo) on renal function and on renal expression of Oat1, Oat3, and Mrp2 in a model of mercuric chloride (HgCl2)-induced renal damage. Four experimental groups of adult male Wistar rats were used: Control, Epo, HgCl2, and Epo + HgCl2. Epo (3000 IU/kg, b.w., i.p.) was administered 24 h before HgCl2 (4 mg/kg, b.w., i.p.). Experiments were performed 18 h after the HgCl2 dose. Parameters of renal function and structure were evaluated. The protein expression of Oat1, Oat3 and Mrp2 in renal tissue was assessed by immunoblotting techniques. Mercury levels were determined by cold vapor atomic absorption spectrometry. Pretreatment with Epo ameliorated the HgCl2-induced tubular injury as assessed by histopathology and urinary biomarkers. Immunoblotting showed that pretreatment with Epo regulated the renal expression of mercury transporters in a way to decrease mercury content in the kidney. Epo pretreatment ameliorates HgCl2-induced renal tubular injury by modulation of mercury transporters expression in the kidneys.

Characterization and cytotoxic activity on glial cells of alkaloid-enriched extracts from pods of the plants Prosopis flexuosa and Prosopis nigra (Fabaceae)

 Introduction: Prosopis spp. pods have shown to be a potential source of protein and energy in livestock. However, prolonged ingestion of some of these species produces neurological symptoms in ruminants. Objective: In the present study, the alkaloid content and the in vitro neurotoxic activity of alkaloid enriched-extracts from P. flexuosa and P. nigra pods were determined in order to elucidate the mechanism of animal poisoning caused by these species.  Methods: The main alkaloids present in both extracts were analyzed by high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS). The cytotoxic activity of Prosopis alkaloid enriched-extracts in primary mixed glial cell culture was assessed by phase contrast microscopy and using neutral red, and lactate dehydrogenase (LDH) activity assays. Results: Juliprosine and juliprosopine were identified in P. flexuosa pods, while the absence of these alkaloids in P. nigra was confirmed. Both extracts (5-30 μg/mL) induced in a dose dependent manner, morphological alterations, such as swelling, enlargement and detachment from the culture surface. Consistent with this, decrease in cell viability and release of LDH 48 hours after exposure, revealed that P. flexuosa pods was significantly more cytotoxic than P. nigra. Conclusions: The present study suggest that the cytotoxic effect displayed by both extracts are due to the alkaloid content. However, the presence of the alkaloids juliprosine and juliprosopine in P. flexuosa could explain the greater cytotoxicity on glial cells with respect to P. nigra that was not shown to contain these alkaloids.

Cytotoxic activity induced by the alkaloid extract from Ipomoea carnea on primary murine mixed glial cultures

The prolonged consumption of Ipomoea carnea produces neurologic symptoms in animals and a typical histological lesion, cytoplasmic vacuolization, especially in neurons. The toxic principles of I. carnea are the alkaloids swainsonine and calystegines B₁, B₂, B₃ and C_1. In this study, primary brain cultures from newborn mouse containing mixed glial cells were utilized. These cells were exposed to Ipomoea extracts containing between 0 and 250 μM swainsonine for 48 h. Morphological changes were investigated through Phase Contrast microscopy and Rosenfeld's staining. The extract induced cytoplasmic vacuolization in astrocytes and microglia in a dose dependent manner, being more evident when cultures were exposed to 250 μM of swainsonine. In addition, acridine orange staining evidenced an increase in the number of lysosomes in both microglia and astrocytes cells. Consistent with this, scanning electron microscopy also showed that both types of cells presented morphological characteristics of cell activation. Ultrastructurally, cells showed vacuoles filled with amorphous material and surrounded by a single membrane and also multilayer membranes. Taken together, these findings suggest that swainsonine along with calystegines, are probably responsible for the activation of glial cells due to a possible lysosomal dysfunction and therefore intracellular storage. Our results demonstrate that this in vitro glial cell model is a very good alternative to in vivo studies that require several weeks of animal intoxication to observe similar neurotoxic effects.

[The chest x-ray in acute bronchiolitis: Technical quality, findings, and an assessment of its reliability]

INTRODUCTION

Despite the recommendations of the current Clinical Practice Guidelines, the chest x-ray continues to be a widely used diagnostic test in the assessment of infants with acute bronchiolitis (AB). However, there have not been many studies that have assessed its reproducibility in these patients. In the present study, an evaluation is made on the radiographs, describing their quality, their radiological findings, and provides new evidence on the agreement between observers.

METHOD

Out of a total of 281 infants admitted due to acute bronchiolitis, 140 chest x-rays were performed. Twelve doctors from different specialities evaluated the presence or absence of 10 radiological signs previously agreed by consensus. The level of agreement between 2 observers, and in groups of 3 or more, were analysed using the Cohen and Fleiss kappa index, respectively.

RESULTS

Only 8.5% of the radiographs showed evidence of a complicated AB. The between-observer agreement in groups of 3 or more was medium, and with little variability (kappa: 0.20-0.40). However, between 2 observers, each observer against radiologist, the variability was wider, (kappa: -0.20-0.60). This level of agreement was associated with factors including, the sign to evaluate, the medical specialty, and level of professional experience.

CONCLUSION

The low levels of agreement between observers and the wide variability, makes the chest x-ray an unreliable diagnostic tool, and is not recommended for the assessment of infants with AB.

Elevation of isoprostanes in polycystic ovary syndrome and its relationship with cardiovascular risk factors

PURPOSE

To evaluate the plasma level of 8-isoprostanes in women with polycystic ovary syndrome. To also investigate whether there is a relationship between 8-isoprostanes and several cardiovascular risk factors.

METHODS

A total of 125 women with polycystic ovary syndrome and 169 healthy women were enrolled in this case-control study. 8-Isoprostanes and different parameters were measured in all subjects. Patients were evaluated for the presence of polycystic ovary syndrome according to the Rotterdam Consensus Conference criteria.

RESULTS

8-Isoprostanes levels were significantly higher in patients with polycystic ovary syndrome (138.4 ± 104.1 pg/mL) compared with control group (68.6 ± 34.3 pg/mL) (p < 0.001). The mean of triglycerides, lipid accumulation product, C-reactive protein, homocysteine, insulin, and homeostatic model assessment for insulin resistance were significantly higher in polycystic ovary syndrome patients with high 8-isoprostanes than those with normal 8-isoprostanes (p < 0.05). The Pearson correlation analyses showed that 8-isoprostanes levels in polycystic ovary syndrome group had a positive correlation with waist circumference, triglycerides, low-density lipoprotein cholesterol, apolipoprotein B, homocysteine, insulin, homeostatic model assessment for insulin resistance.

CONCLUSIONS

Patients with polycystic ovary syndrome have higher 8-isoprostanes levels and it is associated with several cardiovascular risk factors.

Evaluating the impact of the biocontrol agent Trichoderma harzianum ITEM 3636 on indigenous microbial communities from field soils

AIM

To investigate the impact of inoculating peanut seeds with the biocontrol agent Trichoderma harzianum ITEM 3636 on the structure of bacterial and fungal communities from agricultural soils.

METHODS AND RESULTS

Polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (PCR-DGGE) and next-generation sequencing (NGS) of amplicons (or marker gene amplification metagenomics) were performed to investigate potential changes in the structure of microbial communities from fields located in a peanut-producing area in the province of Córdoba, Argentina. Fields had history of peanut smut (caused by Thecaphora frezii) incidence. The Shannon indexes (H'), which estimate diversity, obtained from the PCR-DGGE assays did not show significant differences neither for bacterial nor for fungal communities between control and inoculation treatments. On the other hand, the number of operational taxonomic units obtained after NGS was similar between all the analysed samples. Moreover, results of alpha and beta diversity showed that there were no significant variations between the relative abundances of the most representative bacterial and fungal phyla and genera, in both fields.

CONCLUSIONS

Trichoderma harzianum ITEM 3636 decreases the incidence and severity of agriculturally relevant diseases without causing significant changes in the microbial communities of agricultural soils.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our investigations provide information on the structure of bacterial and fungal communities in peanut-producing fields after inoculation of seeds with a biocontrol agent.

Tolerance of triazole-based fungicides by biocontrol agents used to control Fusarium head blight in wheat in Argentina

Fusarium head blight (FHB) caused by Fusarium graminearum species complex is a devastating disease that causes extensive yield and quality losses to wheat around the world. Fungicide application and breeding for resistance are among the most important tools to counteract FHB. Biological control is an additional tool that can be used as part of an integrated management of FHB. Bacillus velezensisRC 218, Brevibacillus sp. RC 263 and Streptomyces sp. RC 87B were selected by their potential to control FHB and deoxynivalenol production. The aim of this work was to test the tolerance of these biocontrol agents to triazole-based fungicides such as prothioconazole, tebuconazole and metconazole. Bacterial growth was evaluated in Petri dishes using the spread plating technique containing the different fungicides. Bacillus velezensisRC 218 and Streptomyces sp. RC 87B showed better tolerance to fungicides than Brevibacillus sp. RC 263. Complete growth inhibition was observed at concentrations of 20 μg ml^-1 for metconazole, 40 μg ml^-1 for tebuconazole and 80 μg ml^-1 for prothioconazole. The results obtained indicate the possibility of using these biocontrol agents in combination with fungicides as part of an integrated management to control FHB of wheat.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study evaluates the possibility to use biocontrol agents (Bacillus velezensisRC 218, Brevibacillus sp. RC 263 and Streptomyces sp. RC 87B) in combination with triazole-based fungicides to control Fusarium head blight in wheat. The evaluation of biocontrol agents' growth under in vitro conditions was carried out in Petri dishes containing either prothioconazole, tebuconazole or metconazole. Viability studies demonstrated that B. velezensisRC 218 and Streptomyces sp. RC 87B were more tolerant to the fungicides evaluated. Results obtained reflect the possibility to use fungicides at low doses combined with biocontrol agents.

Abstract P3-07-04: EphA2: An emerging target in triple-negative breast cancer

Purpose: Breast tumors classified as 'triple negative' (TNBC) lack defining markers ER/PR/HER2 and do not have clinically-approved targeted therapy. This heterogeneous classification of breast cancers, while immediately responsive to standard chemotherapy, commonly develop resistance and have a poor five-year survival rate. As such, the identification of new therapeutic targets are warranted. As part of our drug discovery platform, we have identified EphA2, as a synthetic-lethal gene that enhances the therapeutic action of FDA-approved, anti-inflammatory compounds. Thus we sought to ascertain the relevance of EphA2-targeted therapy in TNBC, through the evaluation of the marker in preclinical and clinical specimens.

Methods: Sixty-one human and murine breast cancer cell lines or patient-derived xenografts were collated. Protein lysates were created from cells in vitro or from respective tumors established from cells implanted into NSG mice. Forty-nine tumors established (minimum 500mm3) and were surgically removed, fixed in formalin and paraffin embedded. A TMA was constructed with tumor specimens represented twice on the array and reflected all molecular subtypes including; ER-positive (n=5), PR-positive (n=3), HER2-positive (n=9) and TNBC (n=31). Immunostaining for EphA2 was performed with the rabbit monoclonal antibody EphA2 (D4A2) XP (Cell Signaling, #6997) using manufacturer's instructions. Immunostaining was evaluated using the H-score method (score between 0-300), with positive staining for EphA2 reflecting a score of 100 or greater. Analysis of breast cancer lysates by western blot was analyzed by absolute and relative quantitation methods; gene expression data was assessed through Oncomine or using the BreastMark algorithm (http://glados.ucd.ie/BreastMark/). This algorithm integrates gene expression and survival data from 26 datasets on 12 different microarray platforms corresponding to ˜17,000 genes in up to 4,738 samples.

Results: In an integrated gene expression platform (BreastMark), we observed that elevated EphA2 expression was associated with poor prognosis in a cohort of TNBC patient tumor samples. Western blot analysis of EphA2 protein on breast cancer cell lines, identified a greater percentage of TNBC cells expressing EphA2 compared to non-TNBC cell lines. EphA2 immunostaining was observed in the majority of tumor tissues. When present on cancer cells, EphA2 localized to the cell surface; while displaying ubiquitous localization within stromal populations. Cell surface expression of EphA2 on cancer cells was largely restricted to TNBC tumors (11/31 tumors, 35.5%) compared to other molecular subtypes (1/13 non-TNBC tumors, 7.7%; p = 0.0294). Expression of EphA2 in stromal cell populations was similar between groups (TNBC = 22/31, non-TNBC = 11/13; p = 0.1711).

Conclusions: Our analysis determined that EphA2 was specifically expressed on cancer cells derived from tumors with a 'triple-negative' molecular subtype. Collectively our data suggests that EphA2 is an emerging target in TNBC and that therapies directed against EphA2 may provide a significant benefit for a majority of patients that express this marker.

Citation Format: Eckhardt BL, Torres AM, Woodward WA, Krishnamurthy S, Meric-Bernstam F, Ueno NT. EphA2: An emerging target in triple-negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-07-04.

Saturation mapping of regions determining resistance to Ascochyta blight and broomrape in faba bean using transcriptome-based SNP genotyping

Transcriptome-based SNP markers were genotyped in a faba bean map to saturate regions bearing QTL for Ascochyta fabae and broomrape and distinguish positional and functional candidates underlying both resistances. Faba bean is an important food crop worldwide. Marker-assisted selection for disease resistance is a top priority in current faba bean research programs, with pathogens such as Ascochyta fabae and broomrape (Orobanche crenata) being among the major constraints in global faba bean production. However, progress in genetics and genomics in this species has lagged behind that of other grain legumes. Although genetic maps are available, most markers are not in or are too distant from target genes to enable an accurate prediction of the desired phenotypes. In this study, a set of SNP markers located in gene coding regions was selected using transcriptomic data. Ninety-two new SNP markers were genotyped to obtain the most complete map reported so far in the 29H × Vf136 faba bean population. Most of the QTL regions previously described in this cross were enriched with SNP markers. Two QTLs for O. crenata resistance (Oc7 and Oc8) were confirmed. Oc7 and Oc10 located nearby a QTL for A. fabae resistance suggested that these genomic regions might encode common resistance mechanisms and could be targets for selection strategies against both pathogens. We also confirmed three regions in chromosomes II (Af2), III (Af3) and VI associated with Ascochyta blight resistance. The QTLs ratified in the present study are now flanked by or include reliable SNP markers in their intervals. This new information provides a valuable starting point in the search for relevant positional and functional candidates underlying both types of resistance.

Diversity of black Aspergilli isolated from raisins in Argentina: Polyphasic approach to species identification and development of SCAR markers for Aspergillus ibericus

Aspergillus section Nigri is a heterogeneous fungal group including some ochratoxin A producer species that usually contaminate raisins. The section contains the Series Carbonaria which includes the toxigenic species Aspergillus carbonarius and nontoxigenic Aspergillus ibericus that are phenotypically undistinguishable. The aim of this study was to examine the diversity of black aspergilli isolated from raisins and to develop a specific genetic marker to distinguish A. ibericus from A. carbonarius. The species most frequently found in raisins in this study were Aspergillus tubingensis (35.4%) and A. carbonarius (32.3%), followed by Aspergillus luchuensis (10.7%), Aspergillus japonicus (7.7%), Aspergillus niger (6.2%), Aspergillus welwitschiae (4.6%) and A. ibericus (3.1%). Based on inter-simple sequence repeat (ISSR) fingerprinting profiles of major Aspergillus section Nigri members, a sequence-characterized amplified region (SCAR) marker was identified. Primers were designed based on the conserved regions of the SCAR marker and were utilized in a PCR for simultaneous identification of A. carbonarius and A. ibericus. The detection level of the SCAR-PCR was found to be 0.01 ng of purified DNA. The present SCAR-PCR is rapid and less cumbersome than conventional identification techniques and could be a supplementary strategy and a reliable tool for high-throughput sample analysis.

Myositis ossificans traumatica of the medial pterygoid muscle following a third molar extraction

Myositis ossificans (MO) is a rare disease involving heterotopic ossification in the muscle or soft tissue. Myositis ossificans traumatica (MOT) disease presents as a calcification within the injured muscle, resulting from a single or repetitive injury. There are few reports of MOT in the masticatory muscles. The case of a patient with MOT in the medial pterygoid muscle caused by a complication related to the extraction of an erupted upper third molar is reported. The major symptom was severe trismus. Despite surgical treatment, the disease relapsed. MOT can lead to serious consequences for the patient. Its aetiopathogenesis needs to be better understood, so that the most appropriate treatment is established and relapses are minimized. This will improve the quality of life of these patients.

Adverse events related to gastrointestinal endoscopic procedures in pediatric patients under anesthesia care and a predictive risk model (AEGEP Study)

BACKGROUND

Multiple studies have analyzed perioperative factors related to adverse events (AEs) in children who require gastrointestinal endoscopic procedures (GEP) in settings where deep sedation is the preferred anesthetic technique over general anesthesia (GA) but not for the opposite case.

METHODS

We reviewed our anesthesia institutional database, seeking children less than 12 years who underwent GEP over a 5-year period. A logistic regression was used to determine significant associations between preoperative conditions, characteristics of the procedure, airway management, anesthetic approaches and the presence of serious and non-serious AEs.

RESULTS

GA was preferred over deep sedation [77.8% vs. 22.2% in 2178 GEP under anesthesia care (n=1742)]. We found 96 AEs reported in 77 patients, including hypoxemia (1.82%), bronchospasm (1.14%) and laryngospasm (0.91%) as the most frequent. There were 2 cases of severe bradycardia related to laryngospasm/hypoxemia and a case of aspiration resulting in unplanned hospitalization, but there were no cases of intra- or postoperative deaths. Final predictive model for perioperative AEs included age <1 year, upper respiratory tract infections (URTI) <1 week prior to the procedure and low weight for the age (LWA) as independent risk factors and ventilation by facial mask as a protector against these events (p<0.05).

CONCLUSIONS

AEs are infrequent and severe ones are remote in a setting where AG is preferred over deep sedation. Ventilatory AEs are the most frequent and depend on biometrical and comorbid conditions more than anesthetic drugs chosen. Age <1 year, history of URTI in the week prior to the procedure and LWA work as independent risk factors for AEs in these patients.

APL-1, an altered peptide ligand derived from human heat-shock protein 60, selectively induces apoptosis in activated CD4+ CD25+ T cells from peripheral blood of rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a chronic T-cell mediated autoimmune disease that affects primarily the joints. The induction of immune tolerance through antigen-specific therapies for the blockade of pathogenic CD4+ T cells constitutes a current focus of research. In this focus it is attempted to simultaneously activate multiple regulatory mechanisms, such as: apoptosis and regulatory T cells (Tregs). APL-1 is an altered peptide ligand derived from a novel CD4+ T-cell epitope of human heat-shock protein of 60kDa, an autoantigen involved in the pathogenesis of RA. Previously, we have reported that APL-1 induces CD4+ CD25(high)Foxp3+ Tregs in several systems. Here, we investigated the ability of APL-1 in inducing apoptosis in PBMCs from RA patients, who were classified as active or inactive according to their DAS28 score. APL-1 decreased the viability of PBMCs from active but not from inactive patients. DNA fragmentation assays and typical morphological features clearly demonstrated that APL-1 induced apoptosis in these cells. Activated CD4+ CD25+ T cells but not resting CD4+ CD25- T cells were identified as targets of APL-1. Furthermore, CD4+ T-cell responses to APL-1 were found to be dependent on antigen presentation via the HLA-DR molecule. Thus, APL-1 is a regulatory CD4+ T cell epitope which might modulate inflammatory immune responses in PBMCs from RA patients by inducing CD4+ CD25(high)Foxp3+ Tregs and apoptosis in activated CD4+ T cells. These results support further investigation of this candidate drug for the treatment of RA.

Development of amplified fragment length polymorphism (AFLP)-derived specific primer for the detection of Fusarium solani aetiological agent of peanut brown root rot

AIMS

The objective of this work was to design an amplified fragment length polymorphism (AFLP)-derived specific primer for the detection of Fusarium solani aetiological agent of peanut brown root rot (PBRR) in plant material and soil.

METHODS AND RESULTS

Specific primers for the detection of the pathogen were designed based on an amplified region using AFLPs. The banding patterns by AFLPs showed that isolates from diseased roots were clearly distinguishable from others members of the F. solani species complex. Many bands were specific to F. solani PBRR, one of these fragments was selected and sequenced. Sequence obtained was used to develop specific PCR primers for the identification of pathogen in pure culture and in plant material and soil. Primer pair FS1/FS2 amplified a single DNA product of 175 bp. Other fungal isolates occurring in soil, included F. solani non-PBRR, were not detected by these specific primers. The assay was effective for the detection of pathogen from diseased root and infected soils.

CONCLUSIONS

The designed primers for F. solani causing PBRR can be used in a PCR diagnostic protocol to rapidly and reliably detect and identify this pathogen.

SIGNIFICANCE AND IMPACT OF THE STUDY

These diagnostic PCR primers will aid the detection of F. solani causing PBRR in diseased root and natural infected soils. The method developed could be a helpful tool for epidemiological studies and to avoid the spread of this serious disease in new areas.

Comparative genomics to bridge Vicia faba with model and closely-related legume species: stability of QTLs for flowering and yield-related traits

This study presents the development of an enhanced map in faba bean. The map contains 258 loci, mostly gene-based markers, organized in 16 linkage groups that expand 1,875 cM, with an average inter-marker distance of 7.26 cM. The combination of EST-derived markers with a number of markers physically located or previously ascribed to chromosomes by trisomic segregation, allowed the allocation of eight linkage groups (229 markers), to specific chromosomes. Moreover, this approach provided anchor points to establish a global homology among the faba bean chromosomes and those of closely-related legumes species. The map was used to identify and validate, for the first time, QTLs controlling five flowering and reproductive traits: days to flowering, flowering length, pod length, number of seeds per pod and number of ovules per pod. Twelve QTLs stable in the 2 years of evaluation were identified in chromosomes II, V and VI. Comparative mapping suggested the conservation of one of the faba bean genomic regions controlling the character days to flowering in other five legume species (Medicago, Lotus, pea, lupine, chickpea). Additional syntenic co-localizations of QTLs controlling pod length and number of seeds per pod between faba bean and Lotus japonicus are likely. The new genetic map opens the way for further translational studies between faba bean and related legume species, and provides an efficient tool for breeding applications such as QTL analysis and marker-assisted selection.

Therapeutic effect of an altered peptide ligand derived from heat-shock protein 60 by suppressing of inflammatory cytokines secretion in two animal models of rheumatoid arthritis

Rheumatoid arthritis is a systemic autoimmune disease mediated by T cells. Productive engagement of T cell receptors by major histocompatibility complex-peptide leads to proliferation, differentiation and the definition of effector functions. Altered peptide ligands (APL) generated by amino acid substitutions in the antigenic peptide have diverse effects on T cell response. We predicted a novel T cell epitope from human heat-shock protein 60, an autoantigen involved in the pathogenesis of rheumatoid arthritis. Three APLs were designed from this epitope and it was demonstrated that these peptides induce the activation of T cells through their ability to modify cell cycle phase's distribution of CD4+T cells from RA patients. Also, IL-17, TNF-α and IL-10 levels were determined in PBMC from these patients. Unlike the wild-type peptide and the other two APLs, APL2 increased the IL-10 level and suppressed IL-17 secretion in these assays. Therapeutic effect of this APL in adjuvant arthritis (AA) and collagen-induced arthritis (CIA) models was also evaluated. Clinical score, histopathology, inflammatory and regulatory cytokine concentration were monitored in the animals. APL2 efficiently inhibited the progression of AA and CIA with a significant reduction of the clinical and histopathologic score. Therapeutic effect of APL2 on CIA was similar to that obtained with MTX; the standard treatment for RA. This effect was associated with a decrease of TNF-α and IL-17 levels. These results suggest that the therapeutic effect of APL2 is mediated in part by down-regulation of inflammatory cytokines and support the potential use of APL2 as a therapeutic drug in RA patients.

Influence of Planococcus ficus on Aspergillus section Nigri and ochratoxin A incidence in vineyards from Argentina

AIM

The aim of this work was to evaluate the effect of Planococcus ficus infection in red wine grapes on Aspergillus section Nigri and ochratoxin A (OTA) contamination.

METHODS AND RESULTS

During 2006/2007 and 2008/2009 vintages, Merlot, Malbec and Cabernet Sauvignon varieties divided into two categories of grape samples (undamaged and damaged by P. ficus) were evaluated. Regardless of the grape variety and the harvest season evaluated, Aspergillus section Nigri incidence and the mean OTA concentration in damaged berries were significantly higher than that in the undamaged ones (P < 0.05; P < 0.001). The Merlot variety showed the highest level of black aspergilli contamination in damaged grapes during the 2006/2007 vintage (53.5% of infection), whereas Malbec presented the highest incidence during the 2008/2009 vintage (57.6% of infection). The Cabernet Sauvignon variety showed the highest OTA levels, ranging from 0.1 to 140 microg kg(-1).

CONCLUSIONS

The presence of P. ficus in vineyards increased the risk of OTA occurrence in grapes, suggesting the need to implement insect control at preharvest stage to reduce the entry of OTA in the wine production chain.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first report on the influence of P. ficus on the potential risk of OTA contamination in grapes.

Validation of QTLs for Orobanche crenata resistance in faba bean (Vicia faba L.) across environments and generations

Broomrape (Orobanche crenata Forsk.) is a major root-parasite of faba bean (Vicia faba L.), that seriously limits crop cultivation in the whole Mediterranean area. This parasitic weed is difficult to control, difficult to evaluate and the resistance identified so far is of polygenic nature. This study was conducted to identify genetic regions associated with broomrape resistance in recombinant inbred lines (RILs) and to validate their previous location in the original F(2) population derived from the cross between lines Vf6 and Vf136. A progeny consisting of 165 F(6) RILs was evaluated in three environments across two locations in 2003 and 2004. Two hundred seventy seven molecular markers were assigned to 21 linkage groups (9 of them assigned to specific chromosomes) that covered 2,856.7 cM of the V. faba genome. The composite interval mapping on the F(6) map detected more quantitative trait loci (QTL) than in the F(2) analysis. In this sense, four QTLs controlling O. crenata resistance (Oc2-Oc5) were identified in the RI segregant population in three different environments. Only Oc1, previously reported in the F(2) population, was not significant in the advanced lines. Oc2 and Oc3 were found to be associated with O. crenata resistance in at least two of the three environments, while the remaining two, Oc4 and Oc5, were only detected in Córdoba-04 and Mengíbar-04 and seemed to be environment dependent.

Improved J-compensated sequences based on short composite pulses

Efficient J-compensated sequences that are shorter in duration and use less RF pulses have been created from short but very efficient composite 90 degrees RF pulses. The improved J-compensation transforms in-phase into antiphase magnetization and can be incorporated in any pulse sequence that involves evolution of heteronuclear J-couplings. The compensated sequences were tested and incorporated into an HMBC sequence. J-compensated experiments referred to as HMBC-J45 + 90A and HMBC-J45 + 90B, were found to be effective over a wide range of J values.

Molecular characterization of Aspergillus section Flavi isolates collected from peanut fields in Argentina using AFLPs

AIMS

The objectives of this study were: (i) to evaluate genetic relatedness among Aspergillus section Flavi strains isolated from soil and peanut seeds in Argentina; (ii) to determine if AFLP molecular markers could be useful to identify isolates up to species level, and to correlate these markers with the isolates' toxigenic potentials and/or vegetative compatibility group (VCG) affiliations.

METHODS AND RESULTS

Amplified fragment length polymorphism (AFLPs) analysis was applied to compare 82 isolates of Aspergillus section Flavi. Cluster analysis showed a clear separation of A. flavus and A. parasiticus, and comparison of fingerprints revealed several specific markers for each group of isolates. AFLP analysis indicates that no genotypical differences can be established between aflatoxigenic and nonaflatoxigenic producers in both species analysed. In addition, candidate AFLP markers associated with a particular VCG were not found.

CONCLUSIONS

There was a concordance between morphological identification and separation up to species level using molecular markers. The findings of specific bands for A. flavus and A. parasiticus may be useful for the design of specific PCR primers in order to differentiate these species and detect them in food.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present study provides new data on molecular characterization of Aspergillus section Flavi in Argentina.

Development of a new diagnostic marker for growth habit selection in faba bean (Vicia faba L.) breeding

Faba bean varieties with determinacy of the apical meristem are relevant to green production. A diagnostic CAPS (cleavage amplification polymorphic sequence) marker for determinate growth habit (ti) in faba bean was previously developed by Avila et al. (Mol Breed 17:185-190, 2006) but was effective only on a limited range of cultivars or genotypes. In this study, we studied the reasons for this limited application and developed a new marker useful for most faba bean-breeding programs. By designing a new set of primers, the complete genomic Vf_TFL1 sequences from different genotypes contrasting for the character were obtained and additional base changes associated with the ti phenotype were identified. The comparison among faba bean sequences showed that the previous CAPS marker was based on a SNP (single nucleotide polymorphism) at position 469 in the intron 2-3, a silent mutation. On the contrary, a SNP at position 26 that distinguishes determinate and indeterminate growth habit genotypes lead to an amino acid change (Leu-9 to Arg) in the determinate growth habit genotypes that could account for the ti phenotype. A dCAPS marker based on this SNP that creates a TaqI site in the ti allele was developed. The marker was 100% successful in predicting ti phenotypes in a broad range of faba bean germplasm representing all major cultivars historically grown in Europe. The outcome confirms the utility of the new dCAPS in worldwide marker-assisted selection programs.

Population genetic structure ofGibberella zeaeisolated from wheat in Argentina

Gibberella zeae (anamorph Fusarium graminearum) causes Fusarium head blight of wheat. The authors used amplified fragment length polymorphisms (AFLPs) to characterize the genetic structure of two G. zeae populations from commercial wheat fields. The working hypothesis was that sufficient genetic exchange occurs between local populations to prevent significant partitioning of allelic variation. We analysed 216 AFLP loci for 113 isolates collected during the 2002 harvest season. All strains had AFLP profiles typical of G. zeae lineage 7. Both populations were genotypically diverse but genetically similar and potentially part of a larger, randomly mating population, with significant genetic exchange probably occurring between the two subpopulations. Linkage disequilibrium was low, but higher than reported for many other populations of G. zeae, and about 20% of the alleles detected were specific to one of the two subpopulations - results consistent with limited gene exchange between the two subpopulations. This study extends previous work with populations of G. zeae to include those found in Argentina, one of the world's largest wheat growing countries.

Identification and characterization of NBS-LRR class resistance gene analogs in faba bean (Vicia faba L.) and chickpea (Cicer arietinum L.)

A PCR approach with degenerate primers designed from conserved NBS-LRR (nucleotide binding site-leucine-rich repeat) regions of known disease-resistance (R) genes was used to amplify and clone homologous sequences from 5 faba bean (Vicia faba) lines and 2 chickpea (Cicer arietinum) accessions. Sixty-nine sequenced clones showed homologies to various R genes deposited in the GenBank database. The presence of internal kinase-2 and kinase-3a motifs in all the sequences isolated confirm that these clones correspond to NBS-containing genes. Using an amino-acid sequence identity of 70% as a threshold value, the clones were grouped into 10 classes of resistance-gene analogs (RGA01 to RGA10). The number of clones per class varied from 1 to 30. RGA classes 1, 6, 8, and 9 were comprised solely of clones isolated from faba bean, whereas classes 2, 3, 4, 5, and 7 included only chickpea clones. RGA10, showing a within-class identity of 99%, was the only class consisting of both faba bean and chickpea clones. A phylogenetic tree, based on the deduced amino-acid sequences of 12 representative clones from the 10 RGA classes and the NBS domains of 6 known R genes (I2 and Prf from tomato, RPP13 from Arabidopsis, Gro1-4 from potato, N from tobacco, L6 from flax), clearly indicated the separation between TIR (Toll/interleukin-1 receptor homology: Gro1-4, L6, N, RGA05 to RGA10)- and non-TIR (I2, Prf, RPP13, RGA01 to RGA04)-type NBS-LRR sequences. The development of suitable polymorphic markers based on cloned RGA sequences to be used in genetic mapping will facilitate the assessment of their potential linkage relationships with disease-resistance genes in faba bean and chickpea. This work is the first to report on faba bean RGAs.

Cilastatin protection against cyclosporin A-induced nephrotoxicity: clinical evidence

BACKGROUND

Several studies have documented the nephroprotective effect of cilastatin co-administered with imipenem in subjects treated with cyclosporin A. However, no large clinical studies are available to confirm this observation. Here the quality of the evidence on cilastatin nephroprotection against cyclosporin-induced nephrotoxicity is evaluated.

METHODS

The results of all studies where cyclosporin was used alone or combined with imipenem/cilastatin (Tienam) on the same clinical setting were systematically reviewed. Primary outcome was the reduction in serum creatinine concentration. Secondary outcome included development of acute renal failure. Medline was searched using three different retrieval systems (Pubmed, Silver Platter, Knowledge Finder) from January 1966 to February 2006. Attempts were made to contact authors of relevant studies to obtain additional data. Five clinical studies were found, including 125 patients under cyclosporin plus imipenem/cilastatin and 104 under cyclosporin alone.

RESULTS

Cyclosporin increased serum creatinine in all the studies. Average reduction of serum creatinine in cilastatin-treated versus untreated patients was Delta = -0.53 mg/dL (95%CI: -0.90 to -0.17) (Z = 2.84, p = 0.004). Variability between studies was large (from Delta = -0.21 to Delta= -1.59 mg/dL) and heterogeneity pronounced (chi(2) = 8.760, df = 4; p = 0.067). Meta-regression of serum creatinine reduction versus baseline serum creatinine explained 84% of this variability, by the variation in basal serum creatinine. When randomized and observational clinical studies were analyzed separately, conclusions were the same: serum creatinine in cilastatin treated patients was reduced by Delta = -0.98 mg/dL (95%CI: -1.57 to -0.38) in randomized studies (Z = 3.213, p = 0.001) and Delta= -0.32 mg/dL (95%CI: -0.63 to -0.01) in observational studies (Z = 2.013, p = 0.044). Odds Ratio for developing acute renal failure was 0.24 (95% CI: 0.11-0.53, p < 0.0001) on patients simultaneously treated with cyclosporin plus imipenem/cilastatin compared to patients treated with cyclosporin alone.

CONCLUSIONS

Administration of cilastatin may reduce acute cyclosporin nephrotoxicity.

CAPs markers to assist selection for low vicine and convicine contents in faba bean (Vicia faba L.)

The antinutritional factors (ANFs) present in Vicia spp. seeds are a major constraint to the wider utilization of these crops as grain legumes. In the case of faba bean (Vicia faba L.), a breeding priority is the absence vicine and convicine (v-c); responsible for favism in humans and for the reduced animal performance or low egg production in laying hens. The discovery of a spontaneous mutant allele named vc-, which induces a 10-20 fold reduction of v-c contents, may facilitate the process. However, the high cost and difficulty of the chemical detection of v-c seriously restricts the advances in breeding-selection. To identify random amplified polymorphic DNA (RAPD) markers linked to this gene, we have analysed an F(2 )population derived from a cross between a line with high v-c content (Vf6) and the vc- genotype (line 1268). Quantification of v-c was done by spectrophotometry on the parents and the F(2 )population (n = 136). By using bulked segregant analysis (BSA), two RAPD markers linked in coupling and repulsion phase to the allele vc- were identified and further converted into sequence characterized amplified regions (SCARs). Amplification of SCARS was more consistent, although the initial polymorphism between pools was lost. To recover the polymorphisms several approaches were explored. Restriction digestion with HhaI (for SCAR SCH01(620)) and RsaI (for SCAR SCAB12(850)) revealed clear differences between the parental lines. The simultaneous use of the two cleavage amplified polymorphism (CAP) markers will allow the correct fingerprinting of faba bean plants and can be efficiently used in breeding selection to track the introgression of the vc- allele to develop cultivars with low v-c content and improved nutritional value.

Characterization and isolation of L-to-D-amino-acid-residue isomerase from platypus venom

Platypus venom contains an isomerase that reversibly interconverts the second amino-acid residue in some peptides between the L-form and the D-form. The enzyme acts on the natriuretic peptides OvCNPa and OvCNPb, and on the defensin-like peptides DLP-2 and DLP-4, but it does not act on DLP-1. While the isomerization of DLP-2 to DLP-4 is inhibited by the amino-peptidase inhibitor amastatin, it is not affected by the leucine amino-peptidase inhibitor bestatin. The enzyme, that is only present in minute quantities in an extract of the venom gland, is thermally stable up to 55 degrees C, and it was found by anion-exchange chromatography to be acidic. Isolation of the isomerase was carried out by combined ion-exchange chromatography and reverse-phase high performance liquid chromatography (HPLC).

Genetic mapping of QTLs controlling horticultural traits in diploid roses

A segregating progeny set of 96 F1 diploid hybrids (2n = 2x = 14) between "Blush Noisette" (D10), one of the first seedlings from the original "Champneys' Pink Cluster", and Rosa wichurana (E15), was used to construct a genetic linkage map of the rose genome following a "pseudo-testcross" mapping strategy. A total of 133 markers (130 RAPD, one morphological and two microsatellites) were located on the 14 linkage groups (LGs) of the D10 and E15 maps, covering total map lengths of 388 and 260 cM, respectively. Due to the presence of common biparental markers the homology of four LGs between parental maps (D10-1/E15-1 to D10-4/E15-4) could be inferred. Four horticulturally interesting quantitative traits, flower size (FS), days to flowering (DF), leaf size (LS), and resistance to powdery mildew (PM) were analysed in the progeny in order to map quantitative trait loci (QTLs) controlling these traits. A total of 13 putative QTLs (LOD > 3.0) were identified, four for FS, two for flowering time, five for LS, and two for resistance to PM. Possible homologies between QTLs detected in the D10 and E15 maps could be established between Fs1 and Fs3, Fs2 and Fs4, and Ls1 and Ls3. Screening for pairwise epistatic interactions between loci revealed additional, epistatic QTLs (EQTLs) for DF and LS that were not detected in the original QTL analysis. The genetic maps developed in this study will be useful to add new markers and locate genes for important traits in the genus providing a practical resource for marker-assisted selection programs in roses.

Cross-species amplification of Medicago truncatula microsatellites across three major pulse crops

Model plants are facilitating the genetic characterization and comparative mapping of a number of traditional crops. Medicago truncatula has been widely accepted as a model plant to this end as it provides the essential tools for multiple aspects of legume genetics and genomics. A large set of markers from highly conserved M. truncatula gene regions is being created and used to establish a worldwide framework for comparative genomic studies in legumes. We have investigated the potential for cross-species amplification of 209 expressed sequence tag (EST)-based and 33 bacterial artificial chromosome (BAC)-based microsatellites from M. truncatula in the three most important European legume pulses-pea, faba bean and chickpea-that might facilitate future comparative mapping. Our results revealed significant transferability of M. truncatula microsatellites to the three pulses (40% in faba bean, 36.3% in chickpea and 37.6% in pea). The percentage of M. truncatula EST-SSRs (simple sequence repeats) amplified in the three crops (39-43%) was twofold higher than that of the genomic SSRs (21-24%). Sequence analysis determined that the level of conservation in the microsatellite motif was very low, while the flanking regions were generally well conserved. The variations in the sequences were mainly due to changes in the number of repeat motifs in the microsatellite region combined with indel and base substitutions. None of the functional microsatellites showed direct polymorphism among the parental genotypes tested, consequently preventing their immediate use for mapping purposes.

Inhibition of brush border dipeptidase with cilastatin reduces toxic accumulation of cyclosporin A in kidney proximal tubule epithelial cells

BACKGROUND

Cilastatin reduces nephrotoxicity associated with cyclosporin A (CyA) in solid organ and bone marrow transplantation. This appears to be unrelated to changes in renal haemodynamics or CyA metabolism. How cilastatin induces this protection is unclear, but it could result from changes on accumulation of CyA proximal cells.

METHODS

We investigated the effects of cilastatin on primary cultures of pig kidney proximal tubule epithelial cells (PTECs) treated with CyA and FK506. Cell membrane fluidity and membrane-bound cholesterol-rich raft (MBCR) distribution were evaluated by fluorescence microscopy, and CyA transport by radioimmunoassay. Changes in CyA- and FK506-induced apoptosis were also evaluated by electron and light microscopy, flow cytometry, and detection of cytoplasmic nucleosones by enzyme-linked immuosorbent assay.

RESULTS

CyA caused a dose-dependent reduction of cell membrane fluidity, which was prevented by pre-treating PTECs with cilastatin. Cilastatin also inhibited CyA transport across membranes and reduced recovery of CyA in mitochondria and membrane-bound fractions from cilastatin-treated PTECs. This effect was not related to an altered distribution of MBCRs, which are essential for CyA transport. Cilastatin protected against CyA- and FK506-induced apoptosis.

CONCLUSIONS

Prevention of CyA-induced reduction of cell membrane fluidity and inhibition of CyA transport are features of cilastatin's direct effects on PTECs. Unaltered distribution of MBCRs in the presence of cilastatin suggests that cilastatin binding to raft-bound dipeptidases, rather than MBCR modifications, causes interference with CyA transport. These results provide additional insight into the mechanisms and scope of cilastatin nephroprotection.

Isolate and organ-specific QTLs for ascochyta blight resistance in faba bean ( Vicia faba L)

The main objective of the present study was to locate the genomic regions responsible for ascochyta blight resistance in faba bean. Six QTLs were identified with the help of a linkage map constructed from a F(2) population from the cross between the inbred lines 29H (resistant) and VF136 (susceptible). Two pathogenically distinct Ascochyta isolates were used to study the genetic control against them and disease evaluations were performed separately on leaves and stems to investigate whether different genetic systems control resistance in each plant organ, as previously suggested. The six QTLs detected were named Af3 to Af8. Af3 and Af4 were effective against both Ascochyta isolates, Af5 was only effective against isolate CO99-01 while Af6, Af7 and Af8 were only effective against isolate LO98-01. Af3, Af4, Af5 and Af7 were revealed in both leaves and stems. By contrast, Af6 was only effective in leaves and Af8 only in stems. The validity and application of these results in a MAS program is discussed.

Development of a composite map in Vicia faba, breeding applications and future prospects

A composite map of the Vicia faba genome based on morphological markers, isozymes, RAPDs, seed protein genes and microsatellites was constructed. The map incorporates data from 11 F(2) families for a total of 654 individuals all sharing the common female parent Vf 6. The integrated map is arranged in 14 major linkage groups (five of which were located in specific chromosomes). These linkage groups include 192 loci and cover 1559 cM with an overall average marker interval of 8 cM. By joining data of a new F(2) population segregating for resistance to ascochyta, broomrape and others traits of agronomic interest, have been saturated new areas of the genome. The combination of trisomic segregation, linkage analysis among loci from different families with a recurrent parent, and the analysis of new physically located markers, has allowed the establishment of the present status of the V. faba map with a wide coverage. This map provides an efficient tool in breeding applications such as disease-resistance mapping, QTL analyses and marker-assisted selection.

Identification of RAPD markers linked to the Uvf-1 gene conferring hypersensitive resistance against rust (Uromyces viciae-fabae) in Vicia faba L

Bulk segregant analysis was used to identify random amplified polymorphic DNA (RAPD) markers linked to a gene determining hypersensitive resistance in Vicia faba line 2N52 against race 1 of the rust fungus Uromyces viciae-fabae. The monogenic nature of the resistance was determined by analyzing the F(2) population from a cross between resistant line 2N52 and susceptible line VF-176, and further confirmed in the F(2:3)-derived families. Linkage of the RAPD markers was confirmed by screening 55 F(2) plants segregating for resistance. Three RAPD markers (OPD13(736), OPL18(1032) and OPI20(900)) were mapped in coupling phase to the resistance gene for race 1 ( Uvf-1). No recombinants between OPI20(900) and Uvf-1 were detected. Two additional markers (OPP02(1172) and OPR07(930)) were linked to the gene in repulsion phase at a distance of 9.9 and 11.5 cM, respectively. The application of marker-assisted selection to develop new faba bean varieties with rust resistance genes is discussed.

Potential use of antioxidants for control of growth and fumonisin production by Fusarium verticillioides and Fusarium proliferatum on whole maize grain

The effect of interactions between two food grade antioxidants butylated hydroxyanisole (BHA) and propyl paraben (PP, 100, 200, 500 microg g(-1)) and water activity (a(w), 0.995, 0.98, 0.95) of irradiated maize on lag phase prior to growth, growth rate and fumonisin production by Fusarium verticillioides and Fusarium proliferatum was evaluated at 25 degrees C. Both antioxidants had an effect on growth characteristics, and fumonisin production. However, this was dependent on the dose used and the a(w) treatment. At 500 microg g(-1) BHA and PP increased the lag phase prior to growth, and reduced the growth rate of both Fusarium species significantly, especially at 0.95 a(w). Both antioxidants significantly reduced the production of fumonisin by both Fusarium species, especially at 0.98 and 0.95 a(w). These results suggest that these antioxidants have potential for treatment of maize grain for controlling growth of these mycotoxigenic species and prevent fumonisin accumulation.