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1.
J Wound Care ; 23(11): 590, 592-6, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25375407

RESUMEN

Effective wound bed preparation is an essential element in the healing of chronic wounds, including pressure ulcers (PUs). Negative pressure wound therapy (NPWT) reduces oedema, stimulates the formation of granulation tissue and helps remove wound exudate. This helps prepare the wound bed for secondary healing, skin grafting or coverage with flaps. Combining NPWT with an instillation phase using an antiseptic (octenidine based) irrigation solution is a novel approach to PU management. Three patients with Category 4 gluteal PUs were treated with NPWT and instillation fluid, following surgical debridement of necrotic tissue. The aim was to achieve optimal wound bed preparation prior to wound closure by local fasciocutaneous flap. The antiseptic efficacy of octenilin wound irrigation solution in microorganism eradication was quantified by in vitro tests simulating real conditions using leg ulcer vacuum exudates. All wounds completely healed after four weeks, and no adverse incidents occurred due to instillation of octenidine. No recurrence of the PU occurred during a one year follow-up.


Asunto(s)
Antiinfecciosos Locales/uso terapéutico , Nalgas/lesiones , Terapia de Presión Negativa para Heridas , Úlcera por Presión/terapia , Piridinas/uso terapéutico , Infección de Heridas/tratamiento farmacológico , Humanos , Iminas , Masculino , Irrigación Terapéutica , Resultado del Tratamiento , Cicatrización de Heridas
2.
G Chir ; 33(10): 343-5, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23095565

RESUMEN

Pathogenesis, classification and treatment of non-parasitic splenic cysts (NPSCs) are controversial. The utility of percutaneous aspiration of the cyst is not well understood. We report a case of a 32 year-old woman with a symptomatic giant epidermoid cyst of the spleen treated with laparoscopic splenectomy. A percutaneous transcatheter drainage was performed under ultrasound guidance before surgical procedure in order to classify the type of cyst and to choose the best treatment.


Asunto(s)
Quistes/cirugía , Drenaje/métodos , Enfermedades del Bazo/cirugía , Adulto , Femenino , Humanos
3.
Ann Med Surg (Lond) ; 69: 102662, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34429947

RESUMEN

INTRODUCTION: Traumatic peroneal nerve injury (PNI) caused by ski or snowboard edges is a severe but scarcely reported accident. METHODS: In a 20-year retrospective study, all skiers and snowboarders with this injury treated surgically at the Department of Plastic, Reconstructive and Aesthetic Surgery at the Medical University of Innsbruck, Austria, were included, covering a period from 1999/2000 to 2018/2019. RESULTS: In total, 34 patients were included in this study (30 males (88.2%) and 4 (11.8%) females). Of these 34 injured skiers or snowboarders, 33 (97.1%) were recreational athletes and Non-Austrian citizens, and 21 (61.8%) patients sustained accidental injuries without collision. All of the injuries under investigation, i.e., open lacerations, most often with complete transection, were the patients' main injuries. Surgery was performed with direct coaptation in 24 patients (70.6%), and with a suralis nerve graft in the other 10 patients (29.4%). CONCLUSION: Traumatic laceration of the peroneal nerve at the knee level by sharp ski or snowboard edges is a rare but severe injury. Causes for this injury may be multifactorial. Recommendations to reduce the risk of such an injury may follow general instructions and warnings to skiers and snowboarders regarding equipment, familiarity with the region, as well as appropriate skills and training.

4.
Neurol Sci ; 30 Suppl 1: S113-5, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19415439

RESUMEN

Cutaneous allodynia is a frequent complain in headache patients, particularly in those with migraine. A stronger association is present in patients with migraine with aura and with chronic or transformed migraine. The aim of the present study was to investigate if the psychological profile may be related to the presence/absence of allodynia in a sample of headache patients. The psychological profile of patients was assessed by the SCL90R; the presence of allodynia was assessed by a set of semi-structured questions used in previous studies. For the purpose of the study, patients were divided into subgroups according to the headache type (ICDH-II diagnoses), as well as to the temporal pattern (episodic or chronic). A total of 213 consecutive headache patients were studied. Most patients had episodic migraine (116); 37 had tension-type headache. Overall, 156 patients had episodic headache forms, and 57 had chronic forms. As far as allodynia, 93 were non-allodynic; 120 presented allodynic symptoms during their headaches. No significant difference was found between allodynic and non-allodynic patients neither if studied in a whole group (t test, P = 0.10 NS) nor when patients were evaluated comparing different subgroups on the basis of headache type, and of the episodic/chronic pattern. Our results suggest that the presence/absence of allodynia may not be influenced by the psychological profile.


Asunto(s)
Cefalea/psicología , Dolor/psicología , Enfermedad Crónica/psicología , Femenino , Cefalea/epidemiología , Humanos , Masculino , Trastornos Migrañosos/epidemiología , Trastornos Migrañosos/psicología , Dolor/epidemiología , Determinación de la Personalidad , Encuestas y Cuestionarios , Cefalea de Tipo Tensional/epidemiología , Cefalea de Tipo Tensional/psicología
5.
Sci Rep ; 8(1): 2760, 2018 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-29426889

RESUMEN

Engineered silica nanoparticles (NPs) have attracted increasing interest in several applications, and particularly in the field of nanomedicine, thanks to the high biocompatibility of this material. For their optimal and controlled use, the understanding of the mechanisms elicited by their interaction with the biological target is a prerequisite, especially when dealing with cells particularly vulnerable to environmental stimuli like neurons. Here we have combined different electrophysiological approaches (both at the single cell and at the population level) with a genomic screening in order to analyze, in GT1-7 neuroendocrine cells, the impact of SiO2 NPs (50 ± 3 nm in diameter) on electrical activity and gene expression, providing a detailed analysis of the impact of a nanoparticle on neuronal excitability. We find that 20 µg mL-1 NPs induce depolarization of the membrane potential, with a modulation of the firing of action potentials. Recordings of electrical activity with multielectrode arrays provide further evidence that the NPs evoke a temporary increase in firing frequency, without affecting the functional behavior on a time scale of hours. Finally, NPs incubation up to 24 hours does not induce any change in gene expression.


Asunto(s)
Potenciales de Acción/efectos de los fármacos , Nanopartículas , Células Neuroendocrinas/efectos de los fármacos , Neuronas/metabolismo , Dióxido de Silicio/farmacología , Animales , Línea Celular , Expresión Génica/efectos de los fármacos , Hipotálamo/citología , Ratones , Células Neuroendocrinas/fisiología , Neuronas/efectos de los fármacos
9.
Sci Rep ; 6: 28889, 2016 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-27363302

RESUMEN

The fate of human adipose tissue stem cells (ASCs) is largely determined by biochemical and mechanical cues from the extracellular matrix (ECM), which are sensed and transmitted by integrins. It is well known that specific ECM constituents influence ASC proliferation and differentiation. Nevertheless, knowledge on how individual integrins regulate distinct processes is still limited. We performed gene profiling of 18 alpha integrins in sorted ASCs and adipocytes, identifying downregulations of RGD-motif binding integrins integrin-alpha-V (ITGAV) and integrin-alpha-5 (ITGA5), upregulation of laminin binding and leukocyte-specific integrins and individual regulations of collagen and LDV-receptors in differentiated adipocytes in-vivo. Gene function analyses in in-vitro cultured ASCs unraveled differential functions of ITGA5 and ITGAV. Knockdown of ITGAV, but not ITGA5 reduced proliferation, caused p21(Cip1) induction, repression of survivin and specific regulation of Hippo pathway mediator TAZ. Gene knockdown of both integrins promoted adipogenic differentiation, while transgenic expression impaired adipogenesis. Inhibition of ITGAV using cilengitide resulted in a similar phenotype, mimicking loss of pan-ITGAV expression using RNAi. Herein we show ASC specific integrin expression patterns and demonstrate distinct regulating roles of both integrins in human ASCs and adipocyte physiology suggesting a negative impact of RDG-motif signaling on adipogenic differentiation of ASCs via ITGA5 and ITGAV.


Asunto(s)
Diferenciación Celular/genética , Proliferación Celular/genética , Integrina alfa5/genética , Integrina alfaV/genética , Células Madre/metabolismo , Adipocitos/metabolismo , Adipogénesis/genética , Tejido Adiposo/citología , Células Cultivadas , Regulación de la Expresión Génica , Humanos , Integrina alfa5/metabolismo , Integrina alfaV/metabolismo , Interferencia de ARN
10.
Oncogene ; 14(12): 1463-70, 1997 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-9136990

RESUMEN

The low-affinity nerve growth factor receptor p75NTR belongs to a membrane receptor superfamily whose members, in certain cell types, are able to transduce an apoptotic signal. To investigate the effect of p75NTR expression in neuroblastoma cells, we transfected the p75NTR cDNA into SK-N-BE cells, a neuroblastoma cell line that lacks expression of both p75NTR and TrkA. Cell clones expressing elevated levels of p75NTR showed a high degree of cell death by apoptosis, even in serum-supplemented medium. Moreover, the level of apoptosis correlated directly with the expression level of the receptor, indicating that p75NTR could activate the cell death program by itself. Clones expressing p75NTR showed a dramatic increase of cell death when switched into serum-free medium; these cultures rapidly extinguished. This apoptotic effect was greatly inhibited by NGF treatment. Our results support the hypothesis that p75NTR, when it is not bound by NGF, may play a role in neuronal selection during embryonic development and suggest that neuroblastomas may arise from immature neuroblasts that escape programmed cell death. Therefore, the loss of p75NTR expression in developing neural crest cells might be a primary event in the genesis of neuroblastoma.


Asunto(s)
Apoptosis , Neuronas/citología , Receptores de Factor de Crecimiento Nervioso/fisiología , Supervivencia Celular/efectos de los fármacos , Expresión Génica , Humanos , Factores de Crecimiento Nervioso/farmacología , Neuroblastoma , ARN Mensajero/genética , Receptor de Factor de Crecimiento Nervioso , Células Tumorales Cultivadas
11.
J Mol Biol ; 259(3): 337-48, 1996 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-8676373

RESUMEN

Heterogeneous nuclear ribonucleoproteins (hnRNPs) are abundant nuclear polypeptides, most likely involved in different steps of pre-mRNA processing. Protein A1 (34 kDa), a prominent member of the hnRNP family, seems to act by modulating the RNA secondary structure and by antagonizing some splicing factors (SR proteins) in splice-site selection and exon skipping/inclusion. A role of A1 in the nucleo-cytoplasmic transport of RNA has also been proposed. These activities might depend not only on the RNA-binding properties of the protein but also on specific protein-protein interactions. Here we report that A1 can indeed selectively interact, in vitro, both with itself and with other hnRNP basic "core" proteins. Such selective binding is mediated exclusively by the Gly-rich C-terminal domain, where a novel protein-binding motif constituted by hydrophobic repeats can be envisaged. The same domain is necessary and sufficient to promote specific interaction in vivo, as assayed by the yeast two-hybrid assay. Moreover, an in vitro interaction with some SR proteins was also observed. These observations suggest that diverse and specific protein-protein interactions might contribute to the different functions of the hnRNP A1 protein in mRNA maturation.


Asunto(s)
Ribonucleoproteína Heterogénea-Nuclear Grupo A-B , Proteínas de Unión al ARN/metabolismo , Ribonucleoproteínas/metabolismo , Secuencia de Aminoácidos , Arginina/metabolismo , Secuencia de Bases , Sitios de Unión , Glicina/química , Glicina/metabolismo , Ribonucleoproteína Nuclear Heterogénea A1 , Ribonucleoproteínas Nucleares Heterogéneas , Modelos Moleculares , Datos de Secuencia Molecular , Ácidos Nucleicos/química , Ácidos Nucleicos/metabolismo , Fenoles/química , Conformación Proteica , Empalme del ARN , Proteínas de Unión al ARN/química , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/metabolismo , Ribonucleoproteínas/química , Serina/metabolismo , Relación Estructura-Actividad , Especificidad por Sustrato , Levaduras/metabolismo
12.
Plant Dis ; 89(6): 684, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30795404

RESUMEN

The Asian soybean rust caused by the fungus Phakopsora pachyrhizi was cited for the first time in Argentina during the 2002-2003 growing season (3). During 2003-2004, the disease spread to other northern provinces and was also observed in north-central Santa Fe, the main producing soybean province of the country. Because the disease appeared at the end of the crop growing season (late March to early April) it had little or no impact on crop yields. The objectives of this study were to characterize morphologically and pathometrically the disease on soybean and check the presence of P. pachyrhizi on volunteer soybean plants that could eventually carry the disease to the next growing season. The study was conducted in the San Justo Department, Santa Fe Province (between 30 and 31°S latitude), where the presence of the soybean rust was molecularly confirmed by Sistema Nacional Vigilancia y Monitoreo (on-line publication at www.sinavimo.gov.ar ). Three field locations were sampled and identified as M1, M2, and M3. Transversal cuts of soybean leaves through rust lesions and histo-pathological staining were used for micromor-phologic characterization of the developmental stages of P. pachyrhizi. The disease incidence was estimated as the proportion of affected soybean plants and leaves. Average severity, expressed as the percentage of leaf area affected, including chlorosis, was measured on the terminal leaflet of leaves sampled from the lower one-third of the canopy. Three replicates of 10 plants, randomly chosen, were used. The number of uredinia per square centimeter and per lesion (symptomatic foliar area showing chlorosis and necrosis caused by the fungus) was measured on the undersides of the sampled leaflets at ×40 magnification (1). Typical signs and symptoms of P. pachyrhizi coexisted on soybean leaves with brown spot (Septoria glycines), downy mildew (Peronospora manshurica), anthracnose (Colletotrichum truncatum), and blight and leaf spot (Cercospora kikuchii) and also with bacteria (Pseudomonas and Xanthomonas spp.). Uredinia and telia of the P. pachyrhizi cycle were observed. Uredinia were also observed on soybean petioles. The average size of urediniospores (n = 60) was 23.3 × 16.6 µm. Telia were located adjacent to the uredinia. These telia were dark and crusty with four stacked layers of teliospores. Rust incidence in plants was 100% for the three fields, while the incidence in leaves was 100% for M1 and M2 and 60% for M3. Average disease severity was 50.3, 25.6, and 14.8% for M1, M2, and M3, respectively. The mean number of uredinia per square centimeter was 327, 179, and 177, for M1, M2, and M3, respectively. The number of uredinia per lesion ranged from 1 to 6. P. pachyrhizi was also found on volunteer soybean plants that emerged shortly after harvest. On 40 leaflets, the foliar incidence was 25%, showing one to two lesions with one to two uredinios per leaflet (2). The volunteer soybean plants could constitute a potential early source of inoculum. References: (1) M. Marcchetti et al. Phytopathology. 66:461, 1976. (2) R. Pioli et al. La roya asiática en Santa. Fe, Arg. XII Cong. AAPRESID, II Sem. Internac. Soja, Arg. 283-290, 2004. (3) R. L. Rossi. Plant Dis. 87:102, 2003.

13.
Stroke ; 35(9): 2140-4, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15284445

RESUMEN

BACKGROUND AND PURPOSE: Transcatheter closure of patent foramen ovale (PFO) is increasingly being performed and monitored with transthoracic or transesophageal echocardiography, whereas contrast-enhanced transcranial Doppler (ce-TCD), which probably represents the most suitable tool to quantify right-to-left shunt (RLS) in the brain vessels, has been systematically overlooked. Our goal is to prospectively assess efficacy and safety of PFO transcatheter closure using ce-TCD. METHODS: A total of 140 consecutive patients (mean age, 46+/-13 years; male/female ratio, 63/77) with PFO-related large RLS and no other recognized cause of focal cerebral ischemia underwent transcatheter closure. TCD was done preoperatively and 1 month after the procedure in all patients, after 3 months in 120, after 6 months in 112, and after 1 year in 104 patients. RESULTS: Implantation was successful in all patients. During Valsalva strain, a large shunt was still detectable in 31 of 140 (22%), 15 of 120 (13%), 9 of 112 (8%), and 9 of 104 (9%) patients at the 1-, 3-, 6-, and 12-month visits, respectively. Periprocedural and postprocedural complications included atrial fibrillation in 8% and scintillating scotomata in 6% of patients. During the 1-year follow-up period, only 1 transient ischemic attack was recorded in a patient with paroxysmal atrial fibrillation and complete PFO closure. CONCLUSIONS: Transcatheter PFO closure in patients with cryptogenic stroke and large RLS may be less successful than reported previously. TCD appears the ideal tool to follow up the closure process and to identify early, during follow-up, those patients who will be left with a significant shunt. Atrial fibrillation is more common than believed previously and may underlie the occurrence of further cerebrovascular events despite complete PFO closure. Irritative visual phenomena may occur as a consequence of nickel toxicity.


Asunto(s)
Cateterismo Cardíaco , Defectos del Tabique Interatrial/cirugía , Prótesis e Implantes , Adulto , Fibrilación Atrial/etiología , Femenino , Estudios de Seguimiento , Defectos del Tabique Interatrial/complicaciones , Defectos del Tabique Interatrial/diagnóstico , Humanos , Embolia Intracraneal/etiología , Embolia Intracraneal/prevención & control , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Níquel/efectos adversos , Complicaciones Posoperatorias/epidemiología , Periodo Posoperatorio , Estudios Prospectivos , Escotoma/etiología , Tomografía Computarizada por Rayos X , Insuficiencia del Tratamiento , Resultado del Tratamiento , Ultrasonografía Doppler Transcraneal , Maniobra de Valsalva
14.
J Immunol Methods ; 99(1): 25-37, 1987 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-3553334

RESUMEN

A procedure is described for the efficient production of insulin-specific monoclonal antibodies, which involves primary and secondary immunization of BALB/c mice in the hind footpads with bovine or porcine insulin and fusion of lymphocytes from popliteal lymph nodes with a P3x63 murine myeloma line. With this protocol, over 200 positive hybrids were obtained from four separate fusions. Dissociation constants of 31 purified monoclonals, cross-reacting with human insulin, were determined by two different methods and ranged between 4 X 10(-10) and 2 X 10(-6) mol/l. 24 monoclonals were biotinylated, paired in all possible combinations and tested by ELISA for their capacity to simultaneously bind to human insulin in a two-site assay. More than 40 monoclonal pairs were found which formed a sandwich with the hormone. The development of a simple and rapid one-step enzyme immunoassay is described, which involves a first monoclonal bound to the wells of a microtiter plate and a second monoclonal conjugated to alkaline phosphatase. With this assay, insulin can be determined in a range between 0.08 and 7.5 ng/ml in 3-4 h.


Asunto(s)
Anticuerpos Monoclonales , Técnicas para Inmunoenzimas , Insulina/análisis , Fosfatasa Alcalina , Animales , Anticuerpos Monoclonales/aislamiento & purificación , Afinidad de Anticuerpos , Unión Competitiva , Reacciones Cruzadas , Femenino , Humanos , Hibridomas/metabolismo , Métodos , Ratones , Ratones Endogámicos BALB C , Microquímica
15.
Leuk Lymphoma ; 26(5-6): 527-37, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9389360

RESUMEN

The purpose of this paper is to report the clinical characteristics and treatment outcome following different therapeutic approaches in a large series of patients with primary low-grade MALT lymphoma of the stomach. A total of ninety-three patients (median age 63 years) were reviewed. The patients were treated by different modalities (local treatment alone, combined treatment, chemotherapy, antibiotics alone); seven patients refused any treatment. The antibiotic-treated group of patients was prospectively followed with regular endoscopic biopsies, and their responses were histologically evaluated. The 5-years projected overall survival is 82% (95% C.I.; 67%-91%) in the series as a whole. Second tumors were observed in 21.5% of the patients in this series (95% CI 14%v to 31%). There was no apparent difference in overall survival and event-free survival between patients who received different treatments. In the antibiotic-treated group histologic regression of MALT lymphoma was documented in 67% of patients (95% CI 51% to 80%). In conclusion the indolent nature of the disease justifies a conservative approach. The use of antibiotics as first-line therapy may avert or at least postpone the indication for surgical resection in the majority of patients.


Asunto(s)
Linfoma de Células B de la Zona Marginal/terapia , Linfoma no Hodgkin/terapia , Neoplasias Gástricas/terapia , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Antineoplásicos Alquilantes/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Clorambucilo/uso terapéutico , Terapia Combinada , Ciclofosfamida/administración & dosificación , Doxorrubicina/administración & dosificación , Femenino , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Humanos , Linfoma de Células B de la Zona Marginal/patología , Linfoma no Hodgkin/patología , Masculino , Persona de Mediana Edad , Prednisona/administración & dosificación , Pronóstico , Neoplasias Gástricas/patología , Resultado del Tratamiento , Vincristina/administración & dosificación
16.
Eur J Surg Oncol ; 26(8): 815-6, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11087651

RESUMEN

A 38-year-old man arrived at our clinic with symptoms and investigation results (U.S. scan and MR) suggestive of acute calculous cholecystitis. He gave a past history of excision of a stage I melanoma of the shoulder. Metastatic disease was suspected following measurement of CA 19.9 levels and the CT scan. The patient underwent laparotomy and cholecystectomy; pathological examination confirmed the presence of a malignant melanoma metastatic lesion of the gallbladder.


Asunto(s)
Neoplasias de la Vesícula Biliar/secundario , Melanoma/secundario , Adulto , Neoplasias de la Vesícula Biliar/diagnóstico , Neoplasias de la Vesícula Biliar/cirugía , Humanos , Imagen por Resonancia Magnética , Masculino , Melanoma/diagnóstico , Melanoma/cirugía , Hombro , Tomografía Computarizada por Rayos X
17.
Surg Endosc ; 16(5): 814-9, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-11997829

RESUMEN

BACKGROUND: The use of the ultrasonically activated scalpel (UAS) for vessel closure has attained widespread acceptance in many surgical fields. The aim of our study was to investigate the electron microscopic changes to the blood vessels after the application of UAS. METHODS: We collected 10 arterial and 10 venous segments from vessels that had previously been closed by UAS during abdominal operations. The samples were then prepared for ultramicroscopic analysis. Pathological changes in the lumen and the three wall layers of the blood vessel were examined under scanning and transmission electron microscopy. RESULTS: All of the vessel segments showed similar changes: the presence of a blood clot, endothelial cell condensation, coagulative necrosis of the wall, and charring of the vessel at its tip. The edge of the cut vessel were closed by the coagulation bond, which was tied up by collagen fibrils escaped from denaturation. CONCLUSION: When ultrasonic energy is applied to tissues, it changes their structure so as to make a new extracellular matrix.


Asunto(s)
Electrocoagulación/métodos , Terapia por Ultrasonido/métodos , Procedimientos Quirúrgicos Vasculares/métodos , Conducto Cístico/irrigación sanguínea , Conducto Cístico/diagnóstico por imagen , Conducto Cístico/cirugía , Conducto Cístico/ultraestructura , Hemorroides/diagnóstico por imagen , Hemorroides/patología , Hemorroides/cirugía , Humanos , Microscopía Electrónica/métodos , Microscopía Electrónica de Rastreo/métodos , Necrosis , Epiplón/irrigación sanguínea , Epiplón/diagnóstico por imagen , Epiplón/ultraestructura , Estómago/irrigación sanguínea , Estómago/diagnóstico por imagen , Estómago/ultraestructura , Ultrasonografía
18.
Plant Dis ; 88(2): 220, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30812432

RESUMEN

Fusarium graminearum, a pathogen of wheat and corn, was reported recently as a saprophytic fungus colonizing soybean (Glycine max L. Merr.) fruits and seeds at R7 in Argentina (2). To evaluate the capacity of F. graminearum obtained from stem and seeds of symptomatic soybean plants that cause disease on soybean seedlings, isolates were obtained during the 2001 to 2002 growing season from: (i) the basal one-third of stems from field-grown soybean plants, collected at R5, with light brown external and internal discoloration and leaves with interveinal chlorosis; and (ii) soybean seeds with pink tegument. The pathogen was isolated on potato glucose agar acidified with 0.2% lactic acid (PGAA). Isolates were identified as F. graminearum on the basis of growth rate and pigmentation of colonies on PGAA, lack of microconidia (1), and morphology and size of typical macroconidia in sporodochia developed on Spezieller Nährstoffarmer Agar (3). Isolates of F. graminearum, CE135 and CE136 (from wheat) and CE137 (from corn) deposited in the Centro de Referencia en Micología (CEREMIC), Fac. Farmacia y Bioquímica, UNR, Argentina, were used as references in identifying the soybean isolates. Plants (14-day-old) were inoculated separately with stem and seed isolates in the greenhouse at 26 ± 2 and 20 ± 2°C day/night temperature by inserting a piece of mycelium into a wound made with a scalpel in the hypocotyl. A completely randomized block design (RCB) was utilized with four replicate pots with four plants per pot. Plants wounded but without mycelium served as controls. This test was conducted twice (experiments 1 and 2). Another test was completed by burying a thin layer of wheat caryopsis colonized by fungal mycelium of the stem isolate CE170 in the soil of pots. Plants in pots with soil without inoculum served as controls (4). The experiment was conducted twice (experiments 3 and 4) in an RCB with five replications, four plants per replication. The progress of symptoms in experiments 1 and 2 were stem with light brown discoloration around the inoculation point that extended progressively along the stem, interveinal chlorosis or loss of turgence of unifoliate leaves, and interveinal chlorosis of trifoliate leaves followed by plant wilting and death. Twenty-one days after inoculation, average percentages of dead plants (%DP) was 42 and 21% for stem and seed isolates, respectively. For experiments 3 and 4, %DP was 56%, 45 days after emergence. These plants had roots with light brown, necrotic areas. Control plants remained healthy. The pathogen was reisolated from the stem (100%) and root (57%) tissues of symptomatic plants but not from similar tissues of control plants. To our knowledge, this is the first report of a pathogenic relationship between F. graminearum and soybean. References: (1) P. E. Nelson et al. Fusarium species: An Illustrated Manual for Identification. The Pennsylvania State University Press, University Park, PA, 1983. (2) R.N. Pioli et al. Fitopatología 35(2):111, 2000. (3) B. A. Summerell et al. Plant Dis. 87:117, 2003. (4) C. E. Windels. Fusarium. Pages 115-128 in: Methods for Research on Soilborne Phytopathogenic Fungi. L. L. Singleton, J. D. Mihail, and C. M. Rush, eds. The American Phytopathological Society, St. Paul, MN, 1992.

19.
Plant Dis ; 85(1): 95, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30832081

RESUMEN

A soybean stem canker (SSC) outbreak caused by Diaporthe phaseolorum (Cooke & Ellis) Sacc. var. meridionalis Fernández was reported in Santa Fe, Argentina, in 1997 (3). In 1999 an isolate, which was morphologically distinct from D. phaseolorum var. meridionalis, was obtained from stems of field-grown soybean plants exhibiting SSC symptoms, at Oliveros, Santa Fe, Argentina (Lat. 32° 33'S, Lon. 60° 51'W). Disease incidence was 76% in the field where samples were collected. The pathogen was isolated in darkness at 25°C on potatoglucose agar acidified with 0.2% lactic acid (3). The isolate produced white colonies with compact and tufted mycelium that changed to yellow and light tan with age. Stromata and pycnidia were not produced. After 35 days in culture, clustered perithecia were frequently observed on stem segments. Fifty asci, five from each of 10 perithecia, and bicellular, biguttulated ascospores were measured. Ascus mean length was 26.9 ± 2.5 µm and width was 5.3 ± 0.5 µm; ascospore mean length was 8.3 ± 0.6 µm and width was 2.6 ± 0.1µm. Based on these features, the new isolate was classified as D. phaseolorum var. caulivora Athou & Caldwell (1). To further compare the new isolate with previous identified ones, a principal component analysis (PCA, SAS Systems) was performed using seven isolates of D. phaseolorum var. meridionalis, three isolates of D. phaseolorum var. sojae, and two isolates of Phomopsis longicolla. Seventeen morphological characters, all related with the color and texture of the colonies, the presence and shape of the pycnidia and conidia, the presence and type of stromata and perithecia, and the length of the asci, were compared. According to the PCA analysis, the principal characters that discriminated SSC producing isolates (D. phaseolorum var. meridionalis and D. phaseolorum var. caulivora) from non-SSC producing ones (D. phaseolorum var. sojae and P. longicolla) were the development of perithecia (r = 0.98) and low frequency stromata (r = 0.98) in D. phaseolorum var. meridionalis and D. phaseolorum var. caulivora isolates. The principal components that discriminated SSC producing isolates were the more compact and tufted aspect of the mycelia (r = 0.95) and the shorter length of the asci (r = 0.83) in D. phaseolorum var. caulivora compared with D. phaseolorum var. meridionalis. Pathogenicity trials were performed under greenhouse conditions by inoculating D. phaseolorum var. caulivora mycelia in hypocotyls of soybean seedlings by the toothpick method (2). Typical SSC symptoms were observed on susceptible plants and the pathogen was re-isolated and identified from stem portions of the first internode above the inoculation point. Pathogenicity trials were repeated twice with similar results. This is the first report of D. phaseolorum var. caulivora in Argentina and, as far as we know, in all of South America. References: (1) F. A. Fernández et al. 1999. Stem canker. Pages 32-35 in: Compendium of Soybean Diseases, 4th ed. APS Press, St. Paul, MN. (2) B. L. Keeling. Phytopathology 72:807-809, 1982. (3) R. N. Pioli et al. Plant Dis. 81:1215, 1997.

20.
Plant Dis ; 86(12): 1403, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30818452

RESUMEN

The first report of soybean stem canker (SSC) caused by Diaporthe phaseolorum var. caulivora in South America was published in 2001, and was based on an isolate obtained in 1999 at Oliveros, Santa Fe (32°33'S, 60°51'W), Argentina (2). During the 2001 to 2002 growing season, isolates of D. phaseolorum var. caulivora were obtained from stems of field-grown soybeans (Glycine max L.) exhibiting SSC symptoms. Isolates were collected in three localities of the main soybean-producing region of Argentina: Marcos Juárez, Córdoba (32°66'S, 62°10'W); Salto, Buenos Aires (34°20'S, 60°33'W); and Diego de Alvear, Santa Fe (34°21'S, 62°10'W), and disease incidence in the fields was 10 to 60%, 5 to 15%, and 10 to 20%, respectively. The pathogen was isolated on potato glucose agar acidified with 0.2% lactic acid cultured in the dark at 25 ± 1°C. White colonies with compact and tufted mycelium were produced and turned yellow and light tan after 6 days. Appressed and fluffy mycelia were observed in old cultures. Stromata (2 mm diameter) were produced but pycnidia were not detected. After 20 days in culture at 25 ± 1°C under a 12-h light and 12-h dark regime, clustered perithecia developed on stem segments. For each isolate, 10 perithecia, 90 asci, and 30 bicellular, biguttulate ascospores were measured. Averages of asci length and width were 28.3 ± 2.3 and 5.9 ± 0.7 µm, respectively. Averages of ascospores mean length and width were 8.4 ± 0.6 and 2.5 ± 0.4 µm, respectively. These measures were similar to the measures obtained previously (2). Based on these features, the new isolates were classified as D. phaseolorum var. caulivora (Athow & Caldwell). Clustered perithecia, smaller asci and ascospores, and the development of fluffy mycelia with age were the main characteristics that distinguished D. phaseolorum var. caulivora from D. phaseolorum var. meridionalis (1). Pathogenicity trials were performed on cvs. Tracy M, Crockett, Hutchenson, and RA 702 in the greenhouse by placing a small amount of mycelium in soybean seedling hypocotyls wounds made with a scalpel. The pathogen was reisolated from stem portions of the symptomatic plants. Control plants remained healthy. The results reported here show that D. phaseolorum var. caulivora is widely disseminated in the main soybean-producing region of Argentina, where it coexists with D. phaseolorum var. meridionalis (2). The coexistence of both varieties indicates pathogen variability in the region is higher than previously recognized. References: (1) R. N. Pioli et al. Plant Dis. 83:1071, 1999. (2) R. N. Pioli et al. Plant Dis. 85:95, 2001.

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