First Report of Vascular Wilt on Peanut in Mexico Caused by Fusarium incarnatum.

During the fall of 2020, wilt symptoms were presented in a commercial peanut field (Arachis hypogaea L.), variety 'CHAMPS' in Buenavista de Benito Juárez, México (18.460501 N, 98.627100 W). A peanut field was scout 80 days after planting, and plants presenting symptoms of root and crown rot, vascular chlorosis, and tissue death, were sampled. Disease incidence was estimated at 55% of the field. Isolations of the pathogen were made from stem and root tissues. These samples were disinfected by immersion in 1% sodium hypochlorite (NaClO) for 3 min and immersion in 70% ethanol for 1 min with 3 rinses with sterile distilled water. Subsequently, 0.5 cm fragments were removed and placed on media of potato dextrose agar (PDA) and Rose Bengal. Petri dishes were incubated in complete darkness at 26 °C for 7 days. Abundant aerial white mycelium was observed, which turned tan to brown and showed a slightly orange color on the back of the plate. Finally, pure cultures were obtained by single sporing (Aslam et al. 2020). Colonies identified as Fusarium spp. (Leslie and Summerell, 2006) were sub cultured on PDA agar media and Spezieller Nährstoffarmer (Pérez-Vázquez et al. 2022) to observe microscopic characteristics of ten isolates. Colonies of a representative strain (MA-PET-03) produced hyaline septate hyphae, macroconidia dorsoventrally curved, tapering towards both ends of 51-57 × 4.6-5.4 µm (n = 80) with most having 7 septa. Microconidia were unicellular, nonseptate, hyaline, and ovoid, 12.4-20.6 × 3.6-4.1 µm (n = 80). Chlamydospores were abundant and globose 5-11 µm diam (n = 80), intercalary, and solitary in short chains (Figure 1). The observed microscopic characteristics correspond to the description of Fusarium incarnatum (Khoa et al. 2006; Leslie and Summerell, 2006; Xia et al. 2019). The molecular analyses were done with genomic DNA extracted as previously reported by Pérez et al. (2022). A region from the translation elongation factor gene was PCR amplified using EF688/EF1251 primers (Alves et al. 2008) and from the calmodulin (CMDA) gene, using CALDF1 and CALDR1 primers (Noel et al. 2022). The corresponding PCR products were purified with the Gen Elute™ PCR Clean-Up Kit from Sigma-Aldrich Co. (St. Louis Mo. USA) and sequenced at Macrogen Inc. (Seoul, South Korea). The phylogenetic analysis was inferred using the Bayesian Inference method with 1 million generations, final standard deviation was 0.008516. The nucleotide substitution model for Calmodulin (CMDA) was GTR + G and for TEF1 GTR + I + G. This analysis showed that strain MA-PET-03 shared 100% identity (Figure 2) with F. incarnatum ex-type strain CBS 132.73 (CMDA: MN170342; TEF1: JMN1704761) from Pointed gourd (Trichosanthes dioica) in Malawi Africa. The sequences of strain MA-PET-03 were deposited in GenBank (CMDA: OQ679820; TEF1: OQ679821). The pathogenicity tests were carried out with a total of 20 peanut plants, variety 'CHAMPS', 18 days after having been sown in groups of five seeds in 250 g plastic pots, containing a sterilized mixture of Peatmoss and Agrellite (1:1 v./v), with four repetitions. The seeds were inoculated by immersion in 20 mL of spore suspension (106 conidia/mL) isolated from F. incarnatum for 10 min. The plants were maintained in a greenhouse (70% relative humidity and 28 °C) until the appearance of disease symptoms of. Likewise, 10 control plants were inoculated with sterile water. The experiment was repeated twice. The symptoms developed 15 days after inoculation, the plants presented symptoms of chlorosis, wilting of leaves, stems, and roots, a manifestation similar to that observed in the field, while the control plants remained healthy. F. incarnatum was consistently reisolated from inoculated stems and roots and identified by the microscopic characteristics described above. Peanut leaf blight and wilt disease caused by F. incarnatum has been reported in India (Thirumalaisamy et al. 2019). This first report emphasizes that this phytopathogen is a new threat for peanut producers in Mexico, which is why our finding suggests the need to seek new strategies for its control.

Effiiency of the Essential Oil of Porophyllum linaria (Asteraceae) a Mexican Endemic Plant Against Sitophilus zeamais (Coleoptera: Curculionidae).

The insecticidal and repellent effect of essential oil isolated from fresh leaves of Porophyllum linaria on maize weevil was evaluated, as well as the effect on the grain germination after treated. In total, 28 constituents were identified by gas chromatography coupled with mass spectrometry accounting for 99.86% of whole essential oil. The main majority compounds were ß-myrcene (41.94%), D-limonene (20.29%), and estragole (20.03%). Contact toxicity significantly increased with dose and time after treatment. With the 800 ppm (highest concentration), the mortality (%) obtained for the tenth and fifteenth day was 43 and 82%, respectively, whereas with 50 ppm (lowest concentration) 30% mortality was obtained at the end of the experiment (fifteenth day). At 15 d (end of the experiment), the LC50 y LC90 were obtained with values of 329.01 ± 44.35 y 1058.86 ± 117.76 ppm, respectively. For a concentration of 800 ppm, a selection index of zero was obtained, indicating the preference of the pest to the untreated maize (control). The maize grains germination test showed a significant reduction both in the length of hypocotyl and radicle of maize grain. So, in the highest dose, the hypocotyl and radicle length was 1.40 ± 0.34 and 9.14 ± 0.55 cm, respectively, whereas the control group registered 3.28 ± 0.39 and 13.02 ± 0.97 cm, respectively. This finding is promising since as it could result in the identification of botanical substances capable of suppressing maize weevil, Sitophilus zeamais development.

First Report of Macrophomina phaseolina Causing Charcoal Rot of Peanut (Arachis hypogaea L.) in Mexico.

Peanut (Arachis hypogaea L.) is the third most important oilseed crop in the world. The cultivated area in Mexico is currently 52,046 ha with a production of 91,109 ton in 2018 (FAO, 2020). Puebla state ranks third in the national production with 9,313 ton (SIAP, 2020). In September 2019, typical symptoms of charcoal rot (Macrophomina phaseolina (Tassi) Goid.) were observed in about 50% of cultivar Virginia Champs peanuts, and it affecting 1.5 ha located in Chietla (18° 27' 39" N; 98° 37' 11" W), Puebla, Mexico. Diseased plants showed brown discoloration in stem and root rot, with chlorotic foliage, dark microsclerotia were observed on the stem and premature dying. To isolate the causal agent of these symptoms, 20 infected plants were recovered and processed in the laboratory. Ten pieces of stem and root tissue were selected from each plant, cut into small pieces 5-mm in length, superficially disinfested with 1% sodium hypochlorite for 3 min, followed by three rinses with sterile distilled water. Later, dried on sterile paper and placed on Petri plates containing potato dextrose agar (PDA) medium, which were kept at 28°C for 7 days (12 h light and 12 h dark). Four colonies were purified via hyphal tip culture, fungus was consistently isolated from the analyzed tissues; additional microcultures were prepared to observe phenotypic characteristics. Colonies showed dense growth, with a gray initial mycelium, becoming black after 7 days. Microesclerotia with spherical to oblong in shape were observed after 5 days on PDA, with a black coloration, measuring an average of 74 µm width × 110 µm length (n=40). Phylogenetic analysis was conducted by amplification and sequencing of the internal transcribed spacer (ITS) region with the ITS5 and ITS4 primers (White et al. 1990). The obtained sequences were deposited in GenBank database under accession numbers: MW585378, MW585379, MW585380, and MW585381 containing approximately 601 bp of the ITS1-5.8S-ITS2 region (complete sequence); they were 99% identical with the reference sequence of Macrophomina phaseolina (GenBank accession KF951698) isolated in Phaseolus vulgaris from Mexico. Based on the symptoms in the field, colony morphology, color, and shape of the microsclerotia, and molecular identification, the fungus was identified as M. phaseolina (Tassi) Goid. The pathogenicity test was performed on peanut plants cultivar Virginia Champs grown on plastic pots with an autoclaved peat/soil mixture under greenhouse conditions (70% relative humidity and 28°C). Fifty two-month-old peanut plants were inoculated using the toothpick method. The toothpicks were previously sterilized and then placed in Petri plates with each of the four colonies of M. phaseolina until colonization. Small wounds were made with those toothpicks in the roots, and a sterile toothpick was used in the control plants, the assays were performed twice. After three weeks, the inoculated plants exhibited symptoms of wilting chlorosis on the leaves and brown to dark brown discoloration of the vascular ring, while control plants remained healthy. M. phaseolina was re-isolated from symptomatic root tissues and identified by phylogenetic approach, fulfilling Koch's postulates. To date, this fungus affects at least 372 hosts globally causing yield losses. Although in Mexico this fungus has been documented in Glycine max, Ipomoea batatas, Phaseolus vulgaris, Physalis ixocarpa, Saccharum officinarum, Sesamum indicum, Solanum melongena, S. tuberosum, and Sorghum bicolor (Farr and Rossman 2021). However, there are no reports of M. phaseolina as a potential pathogen on peanut; therefore, according to our knowledge, this is the first report of this fungus affecting A. hypogaea in Mexico.

Toxicity and Residual Activity of Insecticides Against Tamarixia triozae (Hymenoptera: Eulophidae), a Parasitoid of Bactericera cockerelli (Hemiptera: Triozidae).

Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) is one of the most economically important pests of potato, tomato, and peppers in Central America, Mexico, the United States, and New Zealand. Its control is based on the use of insecticides; however, recently, the potential of the eulophid parasitoid Tamarixia triozae (Burks) (Hymenoptera: Eulophidae) for population regulation has been studied. Because T. triozae is likely to be exposed to insecticides on crops, the objective of this study was to explore the compatibility of eight insecticides with this parasitoid. The toxicity and residual activity (persistence) of spirotetramat, spiromesifen, beta-cyfluthrin, pymetrozine, azadirachtin, imidacloprid, abamectin, and spinosad against T. triozae adults were assessed using a method based on the residual contact activity of each insecticide on tomato leaf discs collected from treated plants growing under greenhouse conditions. All eight insecticides were toxic to T. triozae. Following the classification of the International Organization of Biological Control, the most toxic were abamectin and spinosad, which could be placed in toxicity categories 3 and 4, respectively. The least toxic were azadirachtin, pymetrozine, spirotetramat, spiromesifen, imidacloprid, and beta-cyfluthrin, which could be placed in toxicity category 2. In terms of persistence, by day 5, 6, 9, 11, 13, 24, and 41 after application, spirotetramat, azadirachtin, spiromesifen, pymetrozine, imidacloprid, beta-cyfluthrin, abamectin, and spinosad could be considered harmless, that is, placed in toxicity category 1 (<25% mortality of adults). The toxicity and residual activity of some of these insecticides allow them to be considered within integrated pest management programs that include T. triozae.

Sequencing, assembly, and genomic annotation of Leucoagaricus gongylophorus LEU18496, a dikarya mutualistic species.

The basidiomycete fungus Leucoagaricus gongylophorus is able to grow in the fungus garden of leaf-cutter ants. This mutualistic interaction has driven the evolutionary adaptation of L. gongylophorus, shaping its metabolism to produce enzymes adept at lignocellulosic biomass degradation. In this study, we undertook the comprehensive sequencing, assembly, and functional annotation of the genome of L. gongylophorus strain LEU18496, mutualistic fungus of the Atta mexicana. Our genomic analyses revealed a distinctive bimodal nature to the genome: a predominant region characterized by AT enrichment and low genetic density, alongside a smaller region exhibiting higher GC content and higher genetic density. The presence of transposable elements (TEs) within the AT-enriched region suggests genomic compartmentalization, facilitating differential evolutionary rates. With a gene count of 6748, the assembled genome of L. gongylophorus LEU18496 surpasses previous reports for this fungal species. Inspection of genes associated with central metabolism unveiled a remarkable abundance of carbohydrate-active enzymes (CAZymes) and fungal oxidative lignin enzymes (FOLymes), underscoring their pivotal roles in the life cycle of this fungus.

Cyanide-Free Copper-Silver Electroplated Coatings on Carbon Steel Exposed to 5% NaClO Bleacher.

This work deals with the development of cyanide-free copper-silver electroplated coatings on AISI-1075 steel and its corrosion behavior under a 5% NaClO solution (commercial household bleach). A cyanide-free bath based on sodium thiosulfate was employed to obtain the silver coatings using current densities from 0.2 to 5.0 mA/cm2 and different concentrations of EDTA (additive). The evolution of the open circuit potential with time showed that silver is anodic with respect to copper, so there were no intense attacks in the silver pores. Adhesion measurements were made on both coatings by the tape test. The behavior against corrosion was evaluated by polarization resistance (Rp) in samples with the best coating adhesion. The best results were obtained with a silver coating of about 20 µm in thickness deposited on copper coating previously polished with colloidal silica. The best performance was attributed to the formation of AgCl as demonstrated by x-ray diffraction and scanning electron microscopy.

Mapping of SARS-CoV-2 in Waldeyer's lymphatic ring and visceral biopsies: the age and the illness duration's impact.

OBJECTIVE: To study the impact of age and the interval between disease diagnosis and death on the organotropism of SARS-CoV-2. METHOD: Patients underwent post-mortem biopsies from lungs, Waldeyer ring, heart, liver, kidneys and bone marrow between 2020‒2021. SARS-CoV-2 organotropism was mapped by using molecular RT-PCR analyses for SARS-CoV2 targeting the Envelope gene (E), the RNA Polymerase Gene (RdRp), and the Nucleocapsid gene (N). Statistical and linear regression analysis was performed to study the impact of age and illness duration in SARS-CoV-2 organotropism. RESULTS: We performed 158 postmortem biopsies in 21 patients, with a mean age of 76 years old. The mean interval between the diagnosis of the infection to the death was 23 days. The RNA of the SARS-CoV-2 was detected in 100% of lung biopsies, 76%‒82% of Waldeyer's ring biopsies, 55% of heart biopsies, 40% of kidney biopsies, 33% of liver and 25% of bone marrow biopsies. Patients who died before the day 9, presented extensive visceral dissemination of SARS-CoV-2 RNA. Most of the patients older than 80 years (90%) presented visceral dissemination of SARS-CoV-2 RNA, while among younger patients, only 3/11 patients presented visceral dissemination of the virus. The relationship between "age" and "illness duration" and multitropism of the virus was statistically significant (p<0.001). CONCLUSION: Disease interval and age were factors that were significantly associated with RT-PCR positive results in multiple organs. Critical COVID-19 patients have multiorganic viral dissemination in early stages. In the critical older patients, multiorganic viral dissemination is the rule.

Analysis of the Propionate Metabolism in Bacillus subtilis during 3-Indolacetic Production.

The genera Bacillus belongs to the group of microorganisms that are known as plant growth-promoting bacteria, their metabolism has evolved to produce molecules that benefit the growth of the plant, and the production of 3-indole acetic acid (IAA) is part of its secondary metabolism. In this work, Bacillus subtilis was cultivated in a bioreactor to produce IAA using propionate and glucose as carbon sources in an M9-modified media; in both cases, tryptophan was added as a co-substrate. The yield of IAA using propionate is 17% higher compared to glucose. After 48 h of cultivation, the final concentration was 310 mg IAA/L using propionate and 230 mg IAA/L using glucose, with a concentration of 500 mg Trp/L. To gain more insight into propionate metabolism and its advantages, the genome-scale metabolic model of B. subtilis (iBSU 1147) and computational analysis were used to calculate flux distribution and evaluate the metabolic capabilities to produce IAA using propionate. The metabolic fluxes demonstrate that propionate uptake favors the production of precursors needed for the synthesis of the hormone, and the sensitivity analysis shows that the control of a specific growth rate has a positive impact on the production of IAA.

Volatiles released by Beauveria bassiana induce oviposition behavior in the fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae).

Microbial volatile organic compounds may act as semiochemicals, inciting different behavioral responses in insects. Beauveria bassiana is an entomopathogenic fungus, and physiological and environmental factors are positively related to fungal virulence. In this study, we examined the volatile profiles produced by eight B. bassiana strains, isolated from soil plots and mycosed insect cadavers, with different speeds of kill and determined if these compounds induce oviposition behavior in Spodoptera frugiperda. Fungal volatilome analysis revealed differences between the isolates. Isolates from mycosed insects showed higher virulence, larger egg mass area and length, and a higher number of eggs by mass, than those obtained from soil. Furthermore, a dilution of the fungal odoriferous compounds increased the insect response, suggesting that S. frugiperda is highly susceptible to the fungal compound's fingerprint. Otherwise, the insect response to the natural blend of volatiles released by the fungus was different from that obtained with 3-methylbutanol, which was the most abundant compound in all isolates. The ability of an entomopathogen to produce volatiles that can induce olfactory stimulation of egg-laying behavior could represent an ecological adaptive advantage in which the entomopathogen stimulates the insect population growth.

Prevalent coinfection and associated factors for Hepatitis B, Hepatitis C, and Human Immunodeficiency Virus in patients submitted to renal replacement therapy: A cross-sectional study of 21 dialysis units in the State of Mexico.

BACKGROUND: Chronic kidney disease (CKD) predispose to viral coinfections in patients submitted to renal replacement therapy (RRT); nevertheless, few reports have been performed to elucidate the current epidemiology within this population in Mexico. AIM: To estimate the prevalence of HBV, HCV, and HIV coinfection and to explore factors associated with prevalent coinfection in patients living with renal failure undergoing to RRT. METHODS: A multicenter cross-sectional recruitment across 21 units at the Mexican Institute of Social Security (IMSS) at the State of Mexico was performed during 2019. A standardized clinical questionnaire was performed to elucidate individual and relatives-related conditions. A treatment facility questionnaire was applied to the chief responsible of each unit to explore treatment facility variables. Serological testing, clinical, biochemical, and anthropometrical parameters were extracted from clinical records. RESULT: In 1,304 patients (57.5% male, mean age 45.5 (SD: 15.6) years, and 95.8% in hemodialysis), the prevalence of any viral coinfection was 3.14% (95% CI: 2.32%-4.23%). The highest viral coinfection prevalence were for HCV, HBV, and HIV, in which men and subjects diagnosed after 2010's had the highest rates. We identify that being submitted to peritoneal dialysis, being treated in a surrogated dialysis center and living with a close relative with prior hepatitis coinfection were associated factors for any viral coinfection. CONCLUSION: In patients submitted to RRT, the prevalence of viral coinfection remains high compared with general population. Screening strategies, medical awareness and targeted public healthcare policies should prioritize better care practices within patients submitted to RRT in Mexico.

Biological Control of Charcoal Rot in Peanut Crop through Strains of Trichoderma spp., in Puebla, Mexico.

Charcoal rot is an emerging disease for peanut crops caused by the fungus Macrophomina phaseolina. In Mexico, peanut crop represents an important productive activity for various rural areas; however, charcoal rot affects producers economically. The objectives of this research were: (a) to identify and morphologically characterize the strain "PUE 4.0" associated with charcoal rot of peanut crops from Buenavista de Benito Juárez, belonging to the municipality of Chietla in Puebla, Mexico; (b) determine the in vitro and in vivo antagonist activity of five Trichoderma species on M. phaseolina, and (c) determine the effect of the incidence of the disease on peanut production in the field. Vegetable tissue samples were collected from peanut crops in Puebla, Mexico with the presence of symptoms of charcoal rot at the stem and root level. The "PUE 4.0" strain presented 100% identity with M. phaseolina, the cause of charcoal rot in peanut crops from Buenavista de Benito Juárez. T. koningiopsis (T-K11) showed the highest development rate, the best growth speed, and the highest percentage of radial growth inhibition (PIRG) over M. phaseolina (71.11%) under in vitro conditions, in addition, T. koningiopsis (T-K11) showed higher production (1.60 ± 0.01 t/ha-1) and lower incidence of charcoal rot under field conditions. The lowest production with the highest incidence of the disease occurred in plants inoculated only with M. phaseolina (0.67 ± 0.01 t/ha-1) where elongated reddish-brown lesions were observed that covered 40% of the total surface of the main root.

Mapping of SARS-CoV-2 in Waldeyer's lymphatic ring and visceral biopsies: the age and the illness duration's impact

Abstract Objective: To study the impact of age and the interval between disease diagnosis and death on the organotropism of SARS-CoV-2. Method: Patients underwent post-mortem biopsies from lungs, Waldeyer ring, heart, liver, kidneys and bone marrow between 2020-2021. SARS-CoV-2 organotropism was mapped by using molecular RT-PCR analyses for SARS-CoV2 targeting the Envelope gene (E), the RNA Polymerase Gene (RdRp), and the Nucleocapsid gene (N). Statistical and linear regression analysis was performed to study the impact of age and illness duration in SARS-CoV-2 organotropism. Results: We performed 158 postmortem biopsies in 21 patients, with a mean age of 76 years old. The mean interval between the diagnosis of the infection to the death was 23 days. The RNA of the SARS-CoV-2 was detected in 100% of lung biopsies, 76%-82% of Waldeyer's ring biopsies, 55% of heart biopsies, 40% of kidney biopsies, 33% of liver and 25% of bone marrow biopsies. Patients who died before the day 9, presented extensive visceral dissemination of SARS-CoV-2 RNA. Most of the patients older than 80 years (90%) presented visceral dissemination of SARS-CoV-2 RNA, while among younger patients, only 3/11 patients presented visceral dissemination of the virus. The relationship between "age" and "illness duration" and multitropism of the virus was statistically significant (p< 0.001). Conclusion: Disease interval and age were factors that were significantly associated with RT-PCR positive results in multiple organs. Critical COVID-19 patients have multiorganic viral dissemination in early stages. In the critical older patients, multiorganic viral dissemination is the rule. Level of evidence: 4. Case Series.

[Association between non-steroid antiinflammatory drugs intake and decompensation of heart failure]. / Asociación entre consumo de antiinflamatorios no esteroideos e insuficiencia cardíaca congestiva.

BACKGROUND AND OBJECTIVE: Our purpose was to estimate the association between the intake of non-steriodal anti-inflammatory drugs (NSAIDs) and hospitalization due to heart failure (HF) and to assess the effect of selective COX-2 inhibitors. PATIENTS AND METHOD: This was a case-control study, including 982 patients with HF, and 788 controls, with a history of HF who were hospitalized in 10 hospitals of the community of Madrid. RESULTS: The use of NSAIDs (other than aspirine at low doses) was associated with an increase in the risk of hospitalization due to HF (OR crude = 1.59; 95% interval confidence, 1.20-2.09; OR adjusted, 1.40; 95% interval confidence, 1.03-1.90). CONCLUSIONS: Intake of NSAIDs is associated with an increased risk of hospitalization due to HF, in susceptible patients.

[Effectiveness of endovascular prostheses as initial treatment for superior vena cava syndrome of malignant cause]. / Tratamiento inicial del síndrome de vena cava superior de causa neoplásica mediante endoprótesis.

BACKGROUND AND OBJECTIVE: Superior vena cava syndrome (SVCS) is caused by venous return obstruction often originated by an invading mediastinal tumour. Our objective was to evaluate the usefulness of stents as initial treatment for SVCS of malignant origin. PATIENTS AND METHODS: From December 1996 to August 2010, 120 patients with SVCS were referred for percutaneous treatment. Seventy-six were under oncological follow-up cases and in 44 cases the tumour was unknown. A non-concurrent prospective study was made of 113 patients without prior chemotherapy or radiotherapy, who opted for endovascular treatment as first option. RESULTS: One hundred and two men and 11 women were treated, mean age 61.18 years old (range 45-85). SVCS causes included lung cancer (100), lung metastases (6), compression by enlarged lymph nodes (6), and an embryonic tumour. One hundred and fifty-five prostheses were implanted. One stent was enough in 75 patients, 2 stents in 34, and 3 in 4. Technical success rate was 98.2%. Symptoms disappeared completely in 97 patients and partially in 13. Complications were stent migration (5), epistaxis (1), and post-procedure groin hematoma (1). Seventy-three asymptomatic patients had a mean survival of 210 days (75% primary permeability and 52.9% secondary permeability). CONCLUSIONS: The use of stents in malignant SVCS is a safe and effective procedure for venous obstruction, leading to the immediate disappearance of symptoms, allowing the underlying tumour staging, facilitating the establishment of the best treatment and improving life quality.

[Cervical and mediastinum haematoma secondary to spontaneous thyroid rupture]. / Hematoma cervical y mediastínico secundario a rotura espontánea de tiroides.

We present a case of spontaneous haemorrhage of a thyroid nodule with diffusion of the haematoma to cervical spaces and mediastinum, which began as a progressive cervical mass affecting the airway and which required surgical treatment for control. The diagnosis was made using ultrasonography and cervicothoracic CT scan, giving high quality images to determine the site of bleeding as well as the extent of the process.

Tumores mucinosos del páncreas / Mucinous tumors of the pancreas

Los tumores mucinosos del páncreas son lesiones premalignas que cursan casi siempre de forma asintomática y la mayoría de las veces se realiza su detección de forma incidental. Tanto el diagnóstico como la conducta terapéutica constituyen un reto para las diferentes especialidades involucradas en el manejo de estas lesiones, dadas las diferencias en la historia natural del espectro de las lesiones: benignas, malignas y borderline; de ahí la importancia de los esfuerzos por lograr consensuar criterios en aras de un mejor seguimiento. Interesados por estos elementos se decide realizar esta revisión bibliográfica de los tumores mucinosos del páncreas e identificar los criterios para el diagnóstico y la conducta a seguir. Para lograr este objetivo se revisó la bibliografía más actualizada consultando revistas digitales, impresas y temas obtenidos de diferentes sitios Web, incluyendo la guía del consenso internacional para el manejo de los tumores mucinosos pancreáticos (AU)

Mucinous tumors of the pancreas are premalignant lesions that occur almost always asymptomatic and most of the time they are detected incidentally. Both the diagnosis and therapeutic behavior constitute a challenge for the different specialties involved in the management of these lesions, given the differences in the natural history of the spectrum of lesions: benign, malignant and borderline; hence the importance of efforts to achieve consensus criteria in order to better monitoring. The authors were interested in these items, so it was decided to conduct this bibliographic review on mucinous tumors of the pancreas and to identify the criteria for diagnosis and behavior to follow. To achieve this goal the most updated bibliography was reviewed, it was consulted digital journals, printed ones and themes obtained from different Web sites, including the international consensus guidelines for management of pancreatic mucinous tumors (AU)

Pólipos y lesiones neoplásicas superficiales del colon / Polyps and superficial neoplastic lesions of the colon

En la actualidad está plenamente aceptada la secuencia adenoma-carcinoma. El adenoma o pólipo adenomatoso es una lesión premaligna que precede, en la mayoría de los casos, a la aparición del cáncer colorrectal. Las lesiones neoplásicas superficiales son poco expresivas endoscópicamente; sin embargo, la importancia es vital, ya que su riesgo de invasión es elevado. Actualmente están en desarrollo nuevas técnicas endoscópicas diagnósticas que redundan en un mejor diagnóstico y una toma de conductas terapéuticas acertadas para evitar complicaciones relacionadas tanto con la evolución natural de las lesiones polipoideas del colon como con las dependientes de la acción del endoscopista. Motivados por la importancia de estas lesiones premalignas en el desarrollo del cáncer colorrectal se realizó una revisión bibliográfica con el empleo de libros especializados en este tema, revistas impresas y electrónicas, así como temas de múltiples sitios en la Web(AU)

Regulation of mammalian liver methionine adenosyltransferase.

S-adenosylmethionine (SAM) is an essential metabolite in all cells. SAM is the most important biological methyl group donor and is a precursor in the synthesis of polyamines. Methionine adenosyltransferase (MAT; EC 2.5.1.6) catalyzes the only known SAM biosynthetic reaction from methionine and ATP. In mammalian tissues, three different forms of MAT (MAT I, MAT III and MAT II) have been identified that are the product of two different genes (MAT1A and MAT2A). Although MAT2A is expressed in all mammalian tissues, the expression of MAT1A is primarily restricted to adult liver. In mammals, up to 85% of all methylation reactions and as much as 48% of methionine metabolism occurs in the liver, which indicates the important role of this organ in the regulation of blood methionine. Recent evidence indicates that not only is SAM the main biological methyl group donor and an intermediate metabolite in methionine catabolism, but it is also an intracellular control switch that regulates essential hepatic functions such as liver regeneration and differentiation as well as the sensitivity of this organ to injury. Therefore, knowledge of factors that regulate the activity of MAT I/III, the specific liver enzyme, is essential to understand how cellular SAM levels are controlled.

Linfoma gástrico tipo malt presentación de un caso

Paciente femenina, raza blanca, de 50 años de edad, que acudió a consulta de gastroenterología de la clínica Popular „Simón Bolívar‰ remitida de su área de salud, por presentar dolor abdominal de tipo epigastralgias, de moderada intensidad, de 2 meses de evolución, con sensación de ardor, además de aparecer más recientemente náuseas y vómitos post-prandiales. La endoscopia superior evidenció lesiones nodulares del fondo y ulcerada del cardias, el estudio histopatológico con inmunohistoquímica reveló linfoma no Hodgkin de células B extranodal, del tejido linfoide asociado a mucosa (MALTOMA). Cumplió tratamiento erradicador para el Helicobacter pylori. Las endoscopias evolutivas mostraron evidente mejoría. Catorce meses después, la evaluación histopatológica reportó gastritis crónica atrófica sin atipias, ausencia de infección por Helicobacter pylori. Actualmente está asintomática y tiene seguimiento semestral.

Female patient, Caucasian, 50 years old, who turned up for Gastroenterology consult of the „Simon Bolivar‰Popular Clinic, remitted from their health area , because of epigastric abdominal pain of moderate intensity with two months of evolution, with burning sensation, besides nauseas and vomiting. The upper digestive endoscopy showed a big ulceration in the cardial portion and granulate mucosa in the bottom of stomach. The histological study with inmunohistochemistry revealed a B extranodal cell non Hodgkin lymphoma of mucosa-associated lymphoid tissue (MALT). She completed treatment for eradication of Helicobacter pylori . Fourteen months later, the histopathologic evaluation reported a chronic atrophic gastritis without atypical cells and an absence of infection for Helicobacter pylori. At the moment she is asymptomatic and has a biannual follow-up.