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3.
Int J Tuberc Lung Dis ; 20(12): 1677-1680, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27931346

RESUMEN

The susceptibility of 253 Mycobacterium tuberculosis complex isolates to pyrazinamide (PZA) was assessed using the BACTECTM MGITTM 960 (M960) system. Resistant strains underwent paired repeat testing using 1) a critical concentration of 200 g/ml (PZA-200), and 2) a reduced inoculum of 0.25 ml. They were also examined using the BACTEC 460 (B460) reference method and investigated for pncA mutations. On M960, 37 isolates were resistant. In the PZA-200 assay, 20 of these were resistant and 17 susceptible, while 18 were resistant and 19 susceptible with reduced inoculum. The B460 assay and pncA sequencing confirmed results with reduced inoculum.


Asunto(s)
Antituberculosos/uso terapéutico , Farmacorresistencia Bacteriana Múltiple/genética , Pruebas de Sensibilidad Microbiana , Pirazinamida/uso terapéutico , Amidohidrolasas/genética , Humanos , Mutación , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/genética , Sensibilidad y Especificidad , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico
4.
G Ital Nefrol ; 30(3)2013.
Artículo en Italiano | MEDLINE | ID: mdl-23832481

RESUMEN

This descriptive report describes the case of a 50 year-old woman with bipolar disorder, whose maintenance therapy comprised risperidone, sodium valproato and lithium carbonate without any past occurrence of toxicity. Her past medical history was significant for hypertension, cardiopathy and obesity. She presented with a 1-week history of fever, increasing confusion and slurred speech. At presentation, the patient was somnolent. Laboratory investigations revealed a serum creatinine of 3,6 mg/dl, BUN 45 mg/dl serum lithium 3,0 mEq/L with polyuria defined as more than 3 litres a day. EEG and ECG were abnormal. CT brain scanning and lumbar puncture were negative for brain haemorrage or infection. Lithium toxicity causes impairment of renal concentration and encephalopathy due to lithium recirculation, a mechanism responsible for the so-called cerebro-renal syndrome, where dialysis plays an important role in treatment.The patient was treated with continous veno-venous haemodiafiltration (CVVHDF) over 35 hours with gradual improvement of her general condition and efficacy of renal concentration. Our case highlights a few important points. Lithium nefrotoxicity and neurotoxicity can cause a cerebro-renal syndrome even when serum lithium levels are not particularly raised (2,5-3,5 mEq/L). Haemodialysis is the treatment of choice to reduce the molecular mechanisms of lithium-related changes in urinary concentration and reinstate dopaminergic activity in the brain.


Asunto(s)
Antipsicóticos/efectos adversos , Encefalopatías/inducido químicamente , Encefalopatías/terapia , Hemodiafiltración , Enfermedades Renales/inducido químicamente , Enfermedades Renales/terapia , Carbonato de Litio/efectos adversos , Enfermedad Aguda , Antipsicóticos/administración & dosificación , Biomarcadores/sangre , Trastorno Bipolar/complicaciones , Trastorno Bipolar/tratamiento farmacológico , Índice de Masa Corporal , Encefalopatías/sangre , Creatinina/sangre , Femenino , Cardiopatías/complicaciones , Hemodiafiltración/métodos , Humanos , Hipertensión/complicaciones , Enfermedades Renales/sangre , Carbonato de Litio/administración & dosificación , Persona de Mediana Edad , Obesidad/complicaciones , Factores de Riesgo , Síndrome , Resultado del Tratamiento
5.
Int J Immunopathol Pharmacol ; 26(1): 207-15, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23527723

RESUMEN

Inferior turbinate hypertrophy (ITH) is the main cause of nasal obstruction symptom. This study aimed at investigating whether a particular cellular pattern could be a predictive factor for failure of medical treatment for ITH in patients with rhinitis. Globally, 258 patients with chronic nasal obstruction due to ITH were evaluated by: visual analogue scale assessment of symptoms, skin prick tests, fiber-endoscopy, active anterior rhinomanometry, and nasal cytology. All patients were treated with drugs for 3 months and then re-evaluated. The symptom improvement depended on the different cellular pattern. There was improvement in: 54 (51.4 percent) patients with allergic rhinitis, 72 (69.2 percent) with non-allergic rhinitis with neutrophils (NARNE), 15 (42.8 percent) with non-allergic rhinitis with eosinophils (NARES), and 9 (64.3 percent) with non-allergic rhinitis with mast cells/non-allergic rhinitis with eosinophils and mast cells (NARMA/NARESMA). The non-responders (108; 41.9 percent) were therefore directed towards surgical treatment. Both patients with allergic rhinitis and patients affected by NARES had a higher failure rate to medical treatment compared with NARMA and NARESMA groups (pless than0.01). In conclusion, elevated number of eosinophils, in the nasal secretion of both allergic (allergic rhinitis) and non-allergic (NARES) patients with ITH, can be associated to a higher medical treatment failure rate.


Asunto(s)
Eosinofilia/inmunología , Hipersensibilidad/inmunología , Obstrucción Nasal/inmunología , Rinitis/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Recuento de Células , Citodiagnóstico , Eosinofilia/patología , Eosinófilos/inmunología , Femenino , Humanos , Hipersensibilidad/diagnóstico , Hipersensibilidad/patología , Hipertrofia/diagnóstico , Hipertrofia/inmunología , Hipertrofia/patología , Masculino , Mastocitos/inmunología , Persona de Mediana Edad , Obstrucción Nasal/diagnóstico , Obstrucción Nasal/patología , Neutrófilos/inmunología , Rinitis/diagnóstico , Rinitis/patología , Cornetes Nasales/inmunología , Cornetes Nasales/patología , Adulto Joven
6.
Int J Oral Maxillofac Surg ; 42(3): 364-8, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23201224

RESUMEN

The objective was to investigate the correlation between levels of depression, somatization, and pain-related impairment, as assessed by the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMDs) axis II, and the treatment outcome of a cycle of five weekly injections of hyaluronic acid immediately following arthrocentesis. 57 consecutive patients with a diagnosis of temporomandibular joint (TMJ) osteoarthritis according to the RDC/TMD underwent the treatment protocol and a follow-up assessment at 6 months. Axis II findings were assessed as potential predictors of improvement in visual analogue scale (VAS) values at the end of the observation period with respect to baseline. The percentage of VAS improvement at the end of treatment was inversely related to all the psychosocial variables. The best fitting model identified pain-related impairment (p<0.001) and disability points (p<0.001) as the most significant predictors of VAS changes. The percentage of variance in the outcome variable explained by the significant predictors was high (R(2) 70.5%). All the RDC/TMD axis II psychosocial scores (depression, somatization, and pain-related impairment levels) were inversely correlated with therapeutic outcome. The clinical relevance of these findings is important, since psychosocial diagnosis may be even more important than physical evaluation in terms of prognostic impact.


Asunto(s)
Dolor Crónico/psicología , Ácido Hialurónico/administración & dosificación , Osteoartritis/psicología , Trastornos de la Articulación Temporomandibular/psicología , Viscosuplementos/administración & dosificación , Adulto , Anciano , Artroscopía , Dolor Crónico/complicaciones , Depresión/complicaciones , Depresión/diagnóstico , Depresión/psicología , Femenino , Humanos , Inyecciones Intraarticulares , Masculino , Persona de Mediana Edad , Osteoartritis/complicaciones , Osteoartritis/terapia , Manejo del Dolor , Paracentesis , Valor Predictivo de las Pruebas , Psicometría , Trastornos Somatomorfos/complicaciones , Trastornos Somatomorfos/diagnóstico , Trastornos Somatomorfos/psicología , Trastornos de la Articulación Temporomandibular/complicaciones , Trastornos de la Articulación Temporomandibular/terapia , Resultado del Tratamiento
7.
G Ital Nefrol ; 26(6): 704-8, 2009.
Artículo en Italiano | MEDLINE | ID: mdl-19918753

RESUMEN

Renal artery stenosis (RAS) is a common manifestation of generalized atherosclerosis, frequently involving other vascular districts, particularly the coronary tree. Duplex ultrasonography is the diagnostic procedure of choice for screening outpatients for RAS. We report a case of metabolic syndrome in a 63-year-old obese man with atherosclerosis and low-grade RAS that was an important sign of cardiovascular risk. In fact, cardioscintigraphy and coronary arteriography showed severe coronary artery disease. RAS is an independent predictor of adverse cardiovascular events such as myocardial infarction, stroke, and cardiovascular death. In this case, duplex ultrasonography demonstrated the importance of screening for RAS as the expression of coronary artery disease.


Asunto(s)
Obstrucción de la Arteria Renal/diagnóstico por imagen , Ultrasonografía Doppler en Color , Enfermedad de la Arteria Coronaria/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Obstrucción de la Arteria Renal/complicaciones , Factores de Riesgo
8.
Clin Genet ; 76(1): 91-101, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19659763

RESUMEN

Hypertrophic cardiomyopathy (HCM) is the most frequent genetic cardiovascular disorder worldwide. It is the leading cause of sudden cardiac-related death in young people and a major cause of cardiac failure and death in elderly people. However, HCM frequently goes undiagnosed until the appearance of overt signs and symptoms, thereby delaying prophylactic and therapeutic measures. We screened patients for sarcomeric genes associated with HCM to obtain information that could be useful for an early diagnosis and so limit the severe consequences of silent HCM. We recruited 39 families with HCM from southern Italy and found mutations in 41% of families (12 with familial HCM and 4 with sporadic HCM). The remaining 23 families (59%) were negative for myofilament gene mutations. Of the 12 mutations identified, 8 were novel. Screening of the other family members available revealed that 27 had mutations; 11 of these individuals had no signs or symptoms suggestive of HCM. This study, besides characterizing the spectrum of mutations in another childhood population, and revealing an even greater genetic heterogeneity than formerly recognized, may increase genotype-phenotype correlations, and thus may help to identify asymptomatic candidates for early preventive or therapeutic measures.


Asunto(s)
Cardiomiopatía Hipertrófica/genética , Población Blanca/genética , Adolescente , Edad de Inicio , Cardiomiopatía Hipertrófica/diagnóstico por imagen , Cardiomiopatía Hipertrófica/epidemiología , Niño , Preescolar , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Genotipo , Humanos , Lactante , Recién Nacido , Italia/epidemiología , Masculino , Mutación/genética , Fenotipo , Polimorfismo de Nucleótido Simple/genética , Prevalencia , Sitios de Empalme de ARN/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sarcómeros/genética , Ultrasonografía
9.
Neurology ; 72(19): 1682-8, 2009 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-19433742

RESUMEN

BACKGROUND: Despite the high incidence of acute stroke, only a minority of patients are enrolled in acute stroke treatment trials. We aimed to identify factors associated with participation in clinical trials of novel therapeutic agents for acute stroke. METHODS: Prospective survey of patients with acute stroke <72 hours from onset. A structured interview was administered to the patient or primary decision-maker. If offered participation in an actual acute treatment trial, questions focused on decisions about that trial; otherwise a similar mock trial was proposed. The primary outcome was whether the subject agreed to participate in the proposed trial. RESULTS: A total of 200 subjects (47% patients, 53% proxies) completed the survey: mean age 63 +/- 14 years, 47% women, 44% white, 50% black. A real acute trial was offered to 22%; others were offered a mock trial. Overall, 57% (95% confidence interval: 50%-64%) of respondents stated they would participate in the proposed acute treatment trial. There were no differences with respect to age, sex, race, educational level, self-assessed stroke severity or stroke type, vascular risk factors, or comorbidities. Misconceptions about key research concepts were found in 50% but did not impact participation. Participation was associated with the perceived risk of the proposed trial intervention (p < 0.001), prior general attitudes about research (p < 0.001), and influences attributed to family, religion, and other personal beliefs (p < 0.001). Patients were more likely to participate than proxy decision-makers (p = 0.04). CONCLUSIONS: Demographic factors, clinical factors, and prior knowledge about research have little impact on the decision to participate in acute stroke clinical trials. Preexisting negative attitudes and external influences about research strongly inhibit participation. Patients are more inclined to participate than their proxy decision-makers.


Asunto(s)
Ensayos Clínicos como Asunto/psicología , Recolección de Datos/métodos , Consentimiento Informado/psicología , Competencia Mental/psicología , Cooperación del Paciente/psicología , Accidente Cerebrovascular/tratamiento farmacológico , Enfermedad Aguda/terapia , Anciano , Actitud Frente a la Salud , Investigación Biomédica/ética , Cuidadores/psicología , Cuidadores/estadística & datos numéricos , Ensayos Clínicos como Asunto/estadística & datos numéricos , Cultura , Femenino , Humanos , Consentimiento Informado/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Cooperación del Paciente/estadística & datos numéricos , Educación del Paciente como Asunto/estadística & datos numéricos , Relaciones Médico-Paciente , Estudios Prospectivos , Medición de Riesgo/estadística & datos numéricos , Asunción de Riesgos
10.
Int J Immunopathol Pharmacol ; 21(2): 325-31, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18547476

RESUMEN

Three main types of inflammatory Non-Allergic Rhinitis (NAR) have been defined: NAR infiltrated by eosinophils (NARES), by mast cells (NARMA), and by neutrophils (NARNE). A new particular type has been characterized with current infiltration by eosinophils and mast cells (NARESMA). The aim of this study is to evaluate the clinical and functional characteristics in patients with NARES, NARMA, NARNE, and NARESMA and to define the latter. One hundred and seventy-six NAR patients were prospectively and consecutively evaluated: 52 patients with NARES, 38 with NARMA, 36 with NARNE, and 50 with NARESMA. Clinical features, Quality of Life (QoL), and rhinomanometry were evaluated in all of them. QoL was significantly different in the 4 groups. NARESMA patients had the worst QoL. Nasal function and QoL in NARESMA patients were significantly correlated. Significant associations were shown with both nasal polyps and asthma in NARESMA patients. This study provides the first evidence that NARESMA constitutes a new type of NAR and is a particularly severe disorder.


Asunto(s)
Eosinófilos/patología , Mastocitos/patología , Enfermedades Nasales/patología , Rinitis/patología , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cavidad Nasal/patología , Enfermedades Nasales/psicología , Estudios Prospectivos , Calidad de Vida , Rinomanometría , Pruebas Cutáneas
11.
J Biol Regul Homeost Agents ; 22(1): 73-81, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18394320

RESUMEN

Three main types of inflammatory Non-Allergic Rhinitis (NAR) have been defined: NAR infiltrated by eosinophils (NARES), by mast cells (NARMA), and by neutrophils (NARNE). In the absence of studies that investigated the Quality of Life (QoL) in NAR, the present work is aimed at evaluating the Quality of Life of patients with NARES, NARMA, and NARNE. One hundred thirty one (131) NAR patients were prospectively and consecutively evaluated: 54 patients with NARES, 38 with NARMA, and 39 with NARNE. Their history, nasal infiltration and rhinomanometry were characterized, and Quality of Life (using 2 instruments) was evaluated, and associated to clinical and histological features. Quality of Life was significantly different in the 3 groups (p less than 0.001); NARES patients had the worst Quality of Life. Nasal resistances were significantly higher in the NARES group. Significant associations were shown in NARES patients between Quality of Life and nasal function. This study provides the first evidence that Quality of Life is impaired in NAR as well as in allergic rhinitis. Furthermore, Quality of Life impairment differs among the various forms of NAR, and there is a correlation with the cellular infiltrating type.


Asunto(s)
Eosinófilos/fisiología , Inflamación/fisiopatología , Calidad de Vida , Rinitis/fisiopatología , Adulto , Alérgenos , Animales , Animales Domésticos , Femenino , Estado de Salud , Humanos , Inflamación/clasificación , Inflamación/etiología , Masculino , Manometría , Estudios Prospectivos , Rinitis/etiología , Rinitis/psicología , Sueño , Conducta Social
12.
Clin Ter ; 156(4): 179-81, 2005.
Artículo en Italiano | MEDLINE | ID: mdl-16342519

RESUMEN

AIM: Authors, describing a clinical case of hepatic hydrothorax in absence of ascites, analyse the disease physiopathology and their therapeutic options. PATIENTS AND METHODS: Case report of a mixed aethiology (HCV and alcohol) hepatic cirrhosis, with pleural effusion, without ascites. CONCLUSIONS: Hepatic hydrothorax without ascites is an uncommon complication of cirrhosis with portal hypertension. Treatment could be pharmacological, with diuretics administration, or operating. A simple and cheap method is thoracentesis. If hydrothorax relapses, most effective method is transjugular intrahepatic portosystemic shunt.


Asunto(s)
Hidrotórax/etiología , Hipertensión Portal/complicaciones , Cirrosis Hepática/complicaciones , Humanos , Hidrotórax/terapia , Hipertensión Portal/cirugía , Cirrosis Hepática/terapia , Masculino , Persona de Mediana Edad , Paracentesis , Derivación Portosistémica Intrahepática Transyugular , Punciones , Recurrencia , Resultado del Tratamiento
13.
Eur Ann Allergy Clin Immunol ; 35(8): 306-13, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14653050

RESUMEN

About 30% of women suffer from nasal symptoms during pregnancy. The hormonal changes occurring during pregnancy favour per se mucosal oedema and relaxation of smooth muscles, thus contributing to nasal congestion. The most common forms of rhinitis are allergic, drug-induced, infectious and vasomotor rhinitis. In addition to the detrimental effects that rhinitis can have on quality of life, it is important to correctly treat rhinitis itself since it can influence concomitant asthma, as underlined in ARIA document. In pregnancy, the safety profile of drugs is the primary item to be considered. The American FDA pointed out that foetal damage could not be totally excluded with the majority of antirhinitis drugs. It is recommended to use "older drugs" because more data about their safety are available. Cromones are the safest drugs but, although they need multiple daily administrations. Antihistamines should be considered as second choice drugs, and their use is not recommended during the first three months of pregnancy. Topical steroids are useful in moderate-severe rhinitis, being beclometasone the most documented molecule. Topical vasoconstrictors should not be used continuously because they can induce pharmacological rhinitis. It is not recommended to start specific immunotherapy in pregnancy but it can be continued in patients who benefit from its use. Infective rhinitis should be treated with beta-lactams, cephalosporins or macrolides. Finally it is important to evaluate the cost/usefulness ratio before any drug prescription.


Asunto(s)
Complicaciones del Embarazo/epidemiología , Rinitis/epidemiología , Anomalías Inducidas por Medicamentos/prevención & control , Adulto , Antialérgicos/uso terapéutico , Contraindicaciones , Desensibilización Inmunológica , Femenino , Hormonas Esteroides Gonadales/fisiología , Antagonistas de los Receptores Histamínicos H1 , Humanos , Embarazo , Complicaciones del Embarazo/tratamiento farmacológico , Complicaciones del Embarazo/inmunología , Complicaciones del Embarazo/terapia , Rinitis/clasificación , Rinitis/tratamiento farmacológico , Rinitis/inmunología , Rinitis/terapia , Rinitis Vasomotora/epidemiología , Seguridad
14.
Microbiol Res ; 156(1): 9-12, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11372660

RESUMEN

The wild-type yeast Saccharomyces cerevisiae (S. cerevisiae) is able to export less than 1 percent of the protein to be secreted. The reasons for retention of most of the secretory proteins on the cell surface of S. cerevisiae are unknown. Recently, temperature-sensitive (ts) mutants of S. cerevisiae showing an oversecretion phenotype were isolated. In order to study the influence of the mitochondrial genome status on protein export in yeast cells, we have isolated several types of respiratory impaired mitochondrial mutants of either the parental S. cerevisiae strain or their derivative ts protein-overexporting mutants. In this paper we demonstrate by quantitative analyses of exported proteins and by SDS-PAGE analysis that protein overexport in ts mutants requires mitochondrial genome integrity and function.


Asunto(s)
Proteínas Fúngicas/metabolismo , Mitocondrias/fisiología , Saccharomyces cerevisiae/fisiología , Southern Blotting , ADN Mitocondrial/química , ADN Mitocondrial/genética , ADN Mitocondrial/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Mitocondrias/genética , Mutagénesis , Mutación , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
15.
Can J Microbiol ; 46(11): 1058-65, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11109496

RESUMEN

In the yeast Saccharomyces cerevisiae, mutants are viable with large deletions (rho-), or even complete loss of the mitochondrial genome (rho0). One class of rho- mutants, which is called hypersuppressive, is characterised by a high transmission of the mutated mitochondrial genome to the diploid progeny when mated to a wild-type (rho+) haploid. The nuclear gene CCE1 encodes a cruciform cutting endonuclease, which is located in the mitochondrion and is responsible for the highly biased transmission of the hypersuppressive rho- genome. CCE1 is a Holliday junction specific endonuclease that resolves recombination intermediates in mitochondrial DNA. The cleavage activity shows a strong preference for cutting after a 5'-CT dinucleotide. In the absence of the CCE1 gene product, the mitochondrial genomes remain interconnected and have difficulty segregating to the daughter cells. As a consequence, there is an increase in the fraction of daughter cells that are rho0. In this paper we demonstrate the usefulness of lycorine, together with staining by 4',6-diamidino-2-phenylindole (DAPI), to assay for the mitotic stability of a variety of mitochondrial genomes. We have found that rho+ and rho- strains that contain CT sequences produce a large fraction of rho0 progeny in the absence of CCE1 activity. Only those rho- mitochondrial genomes lacking the CT recognition sequence are unaffected by the cce1 allele.


Asunto(s)
Alcaloides de Amaryllidaceae , Núcleo Celular/genética , Endodesoxirribonucleasas/genética , Mitocondrias/genética , Fenantridinas/farmacología , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Coloración y Etiquetado/métodos , Composición de Base , Cruzamientos Genéticos , ADN Mitocondrial/aislamiento & purificación , Diploidia , Farmacorresistencia Microbiana , Eliminación de Gen , Resolvasas de Unión Holliday , Indoles , Mitocondrias/ultraestructura , Hibridación de Ácido Nucleico , Saccharomyces cerevisiae/ultraestructura
17.
Curr Microbiol ; 34(6): 382-4, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9142747

RESUMEN

In previous papers (Del Giudice et al. Curr Genet 8:493-497, 1984; Massardo et al. Curr Genet 17:455-457, 1985) we have shown that strains of Saccharomyces cerevisiae that are devoid of mitochondrial DNA (rhoo) are resistant to the alkaloid lycorine isolated from Amaryllis plants, whereas strains containing mitochondrial DNA (rho-, mit-, or rho+) are sensitive to this drug. In addition, we were able to show that the so-called hypersuppressive petites, whose mitochondrial genomes consist of short regions of DNA containing an ori sequence,show intermediate resistance. In this paper, we demonstrate that the degree of suppressiveness of a rho- mutant correlates with the degree of resistance to lycorine.


Asunto(s)
Alcaloides/farmacología , Alcaloides de Amaryllidaceae , ADN Mitocondrial/genética , Fenantridinas/farmacología , Saccharomyces cerevisiae/genética , Supresión Genética , Farmacorresistencia Microbiana/genética , Mutación
20.
Theor Appl Genet ; 81(1): 59-63, 1991 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24221159

RESUMEN

Macrosporogenesis and microsporogenesis were investigated in a diploid S. tuberosum x S. chacoense potato hybrid, characterized by more than 50% 2n egg formation. Fifty-five percent of dyad formation of 2n macrospores is ascribed to two meiotic abnormalities: omission of the second meiotic division, occurring at a frequency of 38%, and irregular spindle axis orientation at metaphase I at a frequency of 16%: These abnormalities give origin to a mixture of 2n eggs, composed of mostly second division restitution (SDR) and a small portion of first division restitution (FDR). Microsporogenesis showed rare dyads of 2n microspores depending on parallel spindles observed in anaphase II.

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