In vitro growth and cell wall degrading enzyme production by Argentinean isolates of Macrophomina phaseolina, the causative agent of charcoal rot in corn.

Macrophomina phaseolina is a polyphagous phytopathogen, causing stalk rot on many commercially important species. Damages caused by this pathogen in soybean and maize crops in Argentina during drought and hot weather have increased due its ability to survive as sclerotia in soil and crop debris under non-till practices. In this work, we explored the in vitro production of plant cell wall-degrading enzymes [pectinases (polygalacturonase and polymethylgalacturonase); cellulases (endoglucanase); hemicellulases (endoxylanase) and the ligninolytic enzyme laccase] by several Argentinean isolates of M. phaseolina, and assessed the pathogenicity of these isolates as a preliminary step to establish the role of these enzymes in M. phaseolina-maize interaction. The isolates were grown in liquid synthetic medium supplemented with glucose, pectin, carboxymethylcellulose or xylan as carbon sources and/or enzyme inducers and glutamic acid as nitrogen source. Pectinases were the first cell wall-degrading enzymes detected and the activities obtained (polygalacturonase activity was between 0.4 and 1.3U/ml and polymethylgalacturonase between 0.15 and 1.3U/ml) were higher than those of cellulases and xylanases, which appeared later and in a lesser magnitude. This sequence would promote initial tissue maceration followed by cell wall degradation. Laccase was detected in all the isolates evaluated (activity was between 36U/l and 63U/l). The aggressiveness of the isolates was tested in maize, sunflower and watermelon seeds, being high on all the plants assayed. This study reports for the first time the potential of different isolates of M. phaseolina to produce plant cell wall-degrading enzymes in submerged fermentation.

[Risk factors of persistent disease at 5 years from diagnosis in differentiated thyroid cancer: study of 63 patients]. / Factores relacionados con la persistencia de la enfermedad a los 5 años del diagnóstico de cáncer diferenciado de tiroides: estudio de 63 pacientes.

OBJECTIVE: To identify possible risk factors associated with persistent disease 5 years after total or near-total thyroidectomy in patients with differentiated thyroid cancer (DTC). PATIENTS AND METHOD: Retrospective study evaluating data from 63 patients 5 years after they were first diagnosed of DTC. At this time of the study, 46 subjects were considered disease-free (F group) whereas 17 had evidence of persistent disease or had died from DTC (P group). We compared both groups of patients regarding the following variables: a) variables at diagnosis related to the patient (age, gender) and the tumor (histological type, size, extrathyroidal involvement, vascular invasion, multifocality, lymph node and distant metastases), and b) variables recorded during follow-up: percentage of subjects showing serum stimulated thyroglobulin > or = 10 ng/ml few weeks postoperatively (Tg0) and 6 to 12 months later (Tg1). RESULTS: Male gender, extrathyroidal involvement and lymph node metastases were more frequent in P group than in F group (41 vs. 11%, 60 vs. 18% and 50 vs. 5.5%; p < 0.05). During the follow-up the percentage of patients showing Tg > or = 10 ng/ml was higher in P group compared to F group, both at a few weeks postoperatively and 6 to 12 months later (Tg0, 75 vs. 13%; Tg1, 69% vs. 0; p < 0,05). CONCLUSIONS: In our patients, male gender, extrathyroidal involvement, and lymph node metastases at diagnosis were associated with persistent disease 5 years later. Serum stimulated thyroglobulin had a very high predictive value both just after surgery and in the next 6 to 12 months and could help identifying subjects who need a closer follow-up.

Genetic variability of Phytophthora sojae isolates from Argentina.

Phytophthora sojae causes root and stem rot, one of the most important diseases of soybean worldwide. Genetic diversity of 32 Phytophthora sojae isolates of different geographic origin from Argentina was evaluated with RAPD markers. The isolates were collected from diseased soybean plants and soil samples from Santa Fe, Buenos Aires, C6rdoba and Entre Rios provinces, in the Pampeana Region. DNA was amplified with 20 decanucleotides primers. Seven primers amplified 49 fragments, of which 35 were polymorphic, indicating high variability. RAPD analysis detected intraspecific variability even among isolates of the same geographic origin.

[Nosocomial infections at a neurologic hospital, analysis of 10 years]. / Infecciones nosocomiales en un hospital de pacientes neurológicos, análisis de 10 años.

OBJECTIVE: To describe the results of 10 years of nosocomial infection (NI) surveillance at a neurological center and evaluate the impact of control measures. PATIENTS AND METHODS: A descriptive and retrospective study was performed at a reference center for adult neurologic and neurosurgical patients located in Mexico City. Between 1990 and 2000, the number, site and type of NI were registered. Chi Square test was employed for statistical analysis of numerical data. RESULTS: Mean NI rate observed was 21 episodes per 100 discharges, with a 40% reduction during the period. Predominant NI were urinary tract infections (36%), lower respiratory tract infections (31%), phlebitis (9%), primary bacteremia (7%), surgical wound infections (7%), and pneumonia (4%). Control measures with a definite impact were organization of intravenous therapy teams with reduction in bacteremia (p = 0.009). Changes in preoperative care, hair clipping instead of shaving, clorhexidine shampoo, and technique of long tunneled ventriculostomy with a 57% reduction (p = 0.00006) in infections related with neurosurgical procedures. The increase in staff and equipment renewal of the respiratory therapy service decreased respiratory infections. CONCLUSIONS: The measures that reduced our NI rate may be useful in other centers for neurologic patients.

[About a case of multiple endocrine neoplasia type 1. Review of some clinical manifestations and treatment controversies]. / A propósito de un caso de neoplasia endocrina múltiple tipo 1. Revisión de algunas manifestaciones clínicas y controversias en el tratamiento.

The rare hereditary syndrome, multiple endocrine neoplasia type1 (MEN-1), is known to predispose affected individuals to endocrine neoplasms in a variety of tissues such as the parathyroid glands, the pituitary gland and the gastrointestinal tract. We describe the case of a man with traditionally-described manifestations (hyperparathyroidism and gastrinoma) and with other tumoral lesions arising from endocrine cells (insulinoma, gastric carcinoid, adrenal adenoma and pancreatic non-functioning neuroendocrine tumors) and non-endocrine cells (lipoma and collagenoma). Frequent recurrences in susceptible tissues that are not totally removed (as occurs in hyperparathyroidism and duodenal gastrinoma) and their unknown clinical significance have aroused current controversies in the therapeutic management of these entities, which is briefly reviewed.

Crecimiento in vitro y producción de enzimas degradadoras de pared celular vegetal de aislamientos argentinos de Macrophomina phaseolina, agente causal de la podredumbre carbonosa en maíz / In vitro growth and cell wall degrading enzyme production by Argentinean isolates of Macrophomina phaseolina, the causative agent of charcoal rot in corn

Macrophomina phaseolina is a polyphagous phytopathogen, causing stalk rot on many commercially important species. Damages caused by this pathogen in soybean and maize crops in Argentina during drought and hot weather have increased due its ability to survive as sclerotia in soil and crop debris under non-till practices. In this work, we explored the in vitro production of plant cell wall-degrading enzymes --#91;pectinases (polygalacturonase and polymethylgalacturonase); cellulases (endoglucanase); hemicellulases (endoxylanase) and the ligninolytic enzyme laccase--#93; by several Argentinean isolates of M. phaseolina, and assessed the pathogenicity of these isolates as a preliminary step to establish the role of these enzymes in M. phaseolina-maize interaction. The isolates were grown in liquid synthetic medium supplemented with glucose, pectin, carboxymethylcellulose or xylan as carbon sources and/or enzyme inducers and glutamic acid as nitrogen source. Pectinases were the first cell wall-degrading enzymes detected and the activities obtained (polygalacturonase activity was between 0.4 and 1.3 U/ml and polymethylgalacturonase between 0.15 and 1.3 U/ml) were higher than those of cellulases and xylanases, which appeared later and in a lesser magnitude. This sequence would promote initial tissue maceration followed by cell wall degradation. Laccase was detected in all the isolates evaluated (activity was between 36 U/l and 63 U/l). The aggressiveness of the isolates was tested in maize, sunflower and watermelon seeds, being high on all the plants assayed. This study reports for the first time the potential of different isolates of M. phaseolina to produce plant cell wall-degrading enzymes in submerged fermentation.

Macrophomina phaseolina es un fitopatógeno polífago, causante de podredumbre carbonosa. Los daños que genera en cultivos de soja y maíz bajo siembra directa en Argentina, en períodos secos y calurosos, se incrementaron por su habilidad para sobrevivir como esclerocios en suelos y restos de cosecha. El propósito del trabajo fue estudiar la producción in vitro de enzimas degradadoras de pared celular vegetal (pectinasas --#91;poligalacturonasa y polimetilgalacturonasa--#93;; celulasas --#91;endoglucanasa--#93;; hemicelulasas --#91;endoxilanasa--#93; y la enzima ligninolítica lacasa) de varios aislamientos argentinos de M. phaseolina y evaluar la patogenicidad de esos aislamientos, como paso preliminar para establecer el papel de estas enzimas en la interacción M. phaseolina-maíz. Se estudió la cinética de crecimiento del hongo y la de la producción de dichas enzimas en medios de cultivo líquidos sintéticos con ácido glutámico como fuente de nitrógeno y con pectina, carboximetilcelulosa (CMC) o xilano como fuentes de carbono. Las pectinasas fueron las primeras enzimas detectadas y los máximos títulos registrados (1,4 UE/ml --#91;poligalacturonasa--#93; y 1,2 UE/ml --#91;polimetilgalacturonasa--#93;, respectivamente) superaron a los de celulasas y xilanasas, que aparecieron más tardíamente y en menor magnitud. Esta secuencia promovería la maceración inicial del tejido, seguida luego por la degradación de la pared celular vegetal. Se detectó actividad lacasa en todos los aislamientos (36 a 63 U/l). La agresividad de todos los aislamientos resultó alta en los 3 hospedantes evaluados: semillas de maíz, de girasol y de melón. En este trabajo se investiga por primera vez el potencial de distintos aislamientos de M. phaseolina para producir enzimas degradadoras de pared celular vegetal en cultivo líquido.

Effect of nitrogen sources and vitamins on ligninolytic enzyme production by some white-rot fungi. Dye decolorization by selected culture filtrates.

The effect of amino acids, complex nitrogen sources and vitamin addition on Trametes trogii, Trametes villosa and Coriolus versicolor var. antarcticus ligninolytic enzyme production, was evaluated. Dye decolorization by their culture filtrates was compared. Glutamic acid followed by peptone, were the best N sources for laccase and manganese peroxidase production. The three fungi produced two laccase isoenzymes (molecular weights from 38 up to 150 kDa); their pattern of production was not affected by medium composition. Although the response was not uniform, vitamin addition sometimes stimulated ligninolytic enzyme production, but never inhibited it. Thiamine induced manganese peroxidase production. T. trogii grown in glutamic acid produced culture filtrates with the highest laccase (188.3 U/ml) and manganese peroxidase activities (4.5 U/ml), rendering the best results in decolorization. These crude filtrates were able to decolorize in half hour (at pH 4.5, 30 degrees C): 13%, 23%, 40%, 46%, 82%, 94% and 95% of Gentian Violet, Xylidine, Congo Red, Malachite Green, Remazol Brilliant Blue R, Indigo Carmine and Anthraquinone Blue, respectively.

Pectinolytic enzyme production by Colletotrichum truncatum, causal agent of soybean anthracnose.

BACKGROUND: Colletotrichum truncatum is the most common pathogenic fungus associated with soybean anthracnose, a prevalent disease in Argentina. Pectinolytic enzymes are involved in the pathogenicity of a wide range of plant pathogenic fungi. OBJECTIVES: To explore pectinolytic enzyme production in Argentinian Colletotrichum strains isolated from diseased soybean plants from different geographic locations, as a preliminary step to establish the biological role of the pectinolytic enzymes in the Colletotrichum spp.-soybean system, yet unknown. METHODS: Ten strains were screened for in vitro pectinolytic enzyme production on a defined medium based on pectin as carbon source. RESULTS: All isolates were able to grow in this medium and polymethylgalacturonase (PMG), polygalacturonase (PG) and pectin lyase (PL) activities were detected. On the whole, the peak of polygalacturonases activities preceded the day of maximum growth, while PL activity reached its highest level afterwards. Strain BAFC 3097 (from Santa Fe province) yielded high titles of the three enzymes (1.08U/ml PG, 1.05U/ml PMG, 156U/ml PL), after a short incubation period (7-10 days). Low synthesis of polygalacturonases in cultures containing glucose as unique carbon source suggests that these enzymes are constitutive in contrast with PL, which was not detected. CONCLUSIONS: The disparity observed in enzyme production among strains cannot be related to fungal growth, since no major differences in mycelial yield were found; it was not connected with their geographic origin, but might be associated with differences in virulence among strains not yet evaluated.

Aspectos socioculturales que influyen en los accidentes laborales en los trabajadores de la salud de la salud / Socio-cultural aspects that influence in occupational accidents in health care workers

Los accidentes laborales son todos aquellos estados patológicos derivados de la acción continua de una causa que tenga su origen en el trabajo o en el medio en que se desarrolla el mismo. La industrialización y el modelo económico que ha venido imperando en el mundo, ha traído aparejadas las mejoras en la producción de bienes y servicios, lo que permitió a las poblaciones un acceso más fácil a ellos, pero también trajo consecuencias sociales como la pobreza, el desempleo y la precarización del trabajo, lo que ha impactado de forma muy negativa en la salud de los trabajadores, incrementando el número de accidentados y enfermedades ocupacionales. Todo este panorama en el que se encuentran sumergidos los trabajadores de la salud, donde el desarrollo tecnológico alcanzado y las condiciones del medio ambiente, en general, han modificado su entorno laboral y, por consiguiente, su adaptación en el que los peligros o factores de riesgo en el trabajo se han transformado ocasionando agravios en su salud, se desarrollará en el presente ensayo

Work accidents are those pathological conditions resulting from continued action of a cause that has its origin in the work or in the environment in which it develops. Industrialization and economic model that has prevailed in the world brought about improvements in the production of goods and services that allowed people easier access to them but also brought social consequences such as poverty, unemployment, job insecurity, that has impacted very negatively on the health of workers by increasing the number of accidents and occupational diseases. This panorama which is submerged health care workers where technological development achieved and the conditions of the general environment have modified their work environment and, therefore, its adaptation where hazards or risk factors in the work have transformed causing health grievances will be developed in this essay

Corrientes educativas que han permeado la formación de enfermería en la Escuela Nacional de Enfermería y Obstetricia / Educational fl ows that have permeated the nursing education in the National School of Nursing and Midwifery

Este artículo presenta una revisión de los modelos pedagógicos que tradicionalmente se han usado en la formación del profesional de enfermería de la Escuela Nacional de Enfermería y Obstetricia de la Universidad Nacional Autónoma de México (UNAM) y también presenta cómo esos modelos han infl uido en las características del ejercicio de la profesión. El modelo enseñanza-aprendizaje se ha venido presentando en diversas modalidades, como la tradicionalista, la conductista y actualmente, se pretende que sea constructivista. Finalmente se puede concluir en el presente escrito que a través de la historia de la enfermería se puede observar que el patrón curricular está orientado al desarrollo de habilidades manuales y procedimentales en los que los alumnos, desde el nivel preescolar hasta el superior, conservan un enfoque educativo tradicional con el que se ha formado la mayor parte del personal de la salud. Consecuentemente este modelo educativo genera la pasividad del alumno resaltando la autoridad y el poder del profesor como poseedor del conocimiento

This article presents a review of pedagogical models that traditionally have been used in professional formation of nurses from the National School of Nursing and Midwifery (ENEO) of the National Autonomous University of Mexico (UNAM) and how these models have infl uenced the characteristics of the practice of the profession the teaching learning model has been presented in different modalities, such as traditionalist, behavioral and currently intended to be constructive. Finally it can be concluded in this paper is that through the history of nursing can be seen that the curricular pattern is oriented to the development of manuals and procedural skills, where students from preschool to upper retain a traditional educational approach which has trained the majority of the health care personnel. Consequently this educational model generates student passivity highlighting the power and authority of the teacher as the possessor of knowledge

Infecciones nosocomiales en un hospital de pacientes neurológicos, análisis de 10 años / Nosocomial infections at a neurologic hospital, analysis of 10 years]

OBJECTIVE: To describe the results of 10 years of nosocomial infection (NI) surveillance at a neurological center and evaluate the impact of control measures. PATIENTS AND METHODS: A descriptive and retrospective study was performed at a reference center for adult neurologic and neurosurgical patients located in Mexico City. Between 1990 and 2000, the number, site and type of NI were registered. Chi Square test was employed for statistical analysis of numerical data. RESULTS: Mean NI rate observed was 21 episodes per 100 discharges, with a 40 reduction during the period. Predominant NI were urinary tract infections (36), lower respiratory tract infections (31), phlebitis (9), primary bacteremia (7), surgical wound infections (7), and pneumonia (4). Control measures with a definite impact were organization of intravenous therapy teams with reduction in bacteremia (p = 0.009). Changes in preoperative care, hair clipping instead of shaving, clorhexidine shampoo, and technique of long tunneled ventriculostomy with a 57 reduction (p = 0.00006) in infections related with neurosurgical procedures. The increase in staff and equipment renewal of the respiratory therapy service decreased respiratory infections. CONCLUSIONS: The measures that reduced our NI rate may be useful in other centers for neurologic patients.