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E Guevara

Publications and source records attributed to E Guevara.

9 recordsLinked to original sources
PubMed2004

Evolution of endogenous hormone concentration in embryogenic cultures of carrot during early expression of somatic embryogenesis.

Embryogenic callus and suspension cultures of carrot (Daucus carota L., cv. Nantaise), growing on/in medium including 1 mg/l 2,4-dichlorophenoxy acetic acid (2,4-D), were transferred to medium with or without this plant growth regulator, to impair or induce, respectively, further development of somatic embryos. The endogenous hormone levels of the cultures were determined over 7 days by means of radio-immunoassay, to characterize their evolution in the initial stages of embryo development. In general, levels of indoleacetic acid (IAA) and abscisic acid (ABA) showed only short-lived differences among treatments during this time in both types of tissue analyzed (i.e., a peak of IAA in callus cultures in the absence of 2,4-D, 48 h after medium change, and higher ABA contents 144 h after subculture of suspension cultures in the presence of 2,4-D). Gibberellins (1, 3 and 20) were detected only in suspension cultures devoid of 2,4-D, starting 24 h after subculture. Concerning the evaluated cytokinins-zeatin/zeatin riboside and N6(Delta2-isopentenyl) adenine/N6(Delta2-isopentenyl) adenosine-the most remarkable observation is that high levels of the former generally coincided with low concentrations of the latter, indicating a shift from precursor to the active form, and vice versa.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2001

Effectors of inflammation in actinic prurigo.

BACKGROUND: Actinic prurigo is a specific familial photodermatosis of uncertain pathogenesis. OBJECTIVE: Our purpose was to investigate the immunohistologic presentation of actinic prurigo to explore the involved pathomechanisms. METHODS: The present immunohistochemical study was performed on biopsy specimens from 20 Mexican patients presenting with a severe and perennial form of the disease. RESULTS: The dense inflammatory infiltrate was composed predominantly of helper T type 1 lymphocytes admixed with scattered B-cell lymphoid follicles and numerous dermal dendrocytes. Keratinocytes contained abundant tumor necrosis factor-alpha and calprotectin. CONCLUSION: In subjects genetically predisposed to actinic prurigo, ultraviolet light may trigger excessive tumor necrosis factor-alpha production by keratinocytes whose sustained release in turn exerts its proinflammatory activity and deleterious epidermal effects. Such a cascade of events is in line with the therapeutic benefit already reported when thalidomide is used to treat actinic prurigo.

Adolescent↗
PubMed1995

Percutaneous balloon mitral valvuloplasty: early and late results according to surgical risk and echocardiographic score.

OBJECTIVE AND DESIGN: Early results, complications and follow-up of 70 patients undergoing percutaneous balloon mitral valvuloplasty (BMV) were retrospectively analyzed to establish whether an increased surgical risk or an unfavourable echocardiographic score influenced the results. PATIENTS: The patients were divided into two groups according to the presence (group A, n = 31) or absence (group B, n = 38) of high surgical risk factors. The patients were also divided into two other groups according to the presence (group C, n = 46) or absence (group D, n = 20) of favourable mitral valve anatomy. Group A (high surgical risk) included patients fulfilling at least one of the following criteria: 65 years of age or older; previous surgical commissurotomy; depressed left ventricular function; respiratory or hepatic insufficiency; or previous aortic valve replacement. Mitral valve anatomy was classified as 4 to 16, according to the echocardiographic score established by Abascal et al. Group C patients had echocardiographic score below 8 and group D had echocardiographic scores of 8 or greater. INTERVENTIONS: Mean mitral valve gradient (MVG) and area (MVA) were Doppler-estimated immediately before and 48 h after the BMV. MAIN RESULTS: There were no differences in the early results and complications between groups A and B (MVA 1.8 +/- 0.5 versus 1.9 +/- 0.4 cm2). Final MVA was significantly greater in group C than in group D (MVA 1.9 +/- 0.4 versus 1.6 +/- 0.4 cm2; P = 0.03). There was no difference in the incidence of complications. Over a follow-up period averaging 19.1 months (range 1 to 55), 90.7% of the patients were in New York Heart Association functional class I or II. Four patients had a mitral valve replacement, one had a surgical commissurotomy and one had a second BMV. Two unrelated deaths occurred. There were no differences in the characteristics of the study population and the incidence of events in the follow-up period between groups. CONCLUSIONS: The results and outcome of BMV were unrelated to the general surgical risk, suggesting that this procedure may be used with particular benefit in this group of patients. In contrast, mitral valve anatomy must be considered as an important determinant of the results.

Adult↗
PubMedDate not supplied

Pleuritis by radiation: reports of two cases.

Two cases of pleuritis by radiation, diagnosed by cytology studies of the pleural fluid, are reported. The clinical picture was that of a respiratory infection, with nonproductive cough and pleuritic chest pain. Chest x-ray studies showed a small pleural effusion that was confirmed by a thorax puncture. The aspirated fluid was hemorrhagic, and Papanicolaou studies were negative for tumor cells. However, multiple reactive mesothelial cells with vacuole formation within the cytoplasm and nuclei were seen. The differential diagnosis of pleuritis by radiation should include infectious pleuritis as well as pleural metastasis. A history of previous radiation and the typical findings in cytologic studies are important to confirm the diagnosis.

Aged↗