Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 118
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Mol Phylogenet Evol ; 115: 140-160, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28757445

RESUMEN

This study investigated host-specificity and phylogenetic relationships in Australian galling flies, Fergusonina Malloch (Diptera: Fergusoninidae), in order to assess diversity and explore the evolutionary history of host plant affiliation and gall morphology. A DNA barcoding approach using COI data from 203 Fergusonina specimens from 5gall types on 56 host plant species indicated 85 presumptive fly species. These exhibited a high degree of host specificity; of the 40 species with multiple representatives, each fed only on a single host genus, 29 (72.5%) were strictly monophagous, and 11 (27.5%) were reared from multiple closely related hosts. COI variation within species was not correlated with either sample size or geographic distance. However variation was greater within oligophagous species, consistent with expectations of the initial stages of host-associated divergence during speciation. Phylogenetic analysis using both nuclear and mitochondrial genes revealed host genus-restricted clades but also clear evidence of multiple colonizations of both host plant genus and host species. With the exception of unilocular peagalls, evolution of gall type was somewhat constrained, but to a lesser degree than host plant association. Unilocular peagalls arose more often than any other gall type, were primarily located at the tips of the phylogeny, and did not form clades comprising more than a few species. For ecological reasons, species of this gall type are predicted to harbor substantially less genetic variation than others, possibly reducing evolutionary flexibility resulting in reduced diversification in unilocular gallers.


Asunto(s)
Dípteros/clasificación , Tumores de Planta/clasificación , Animales , Australia , Evolución Biológica , Dípteros/genética , Complejo IV de Transporte de Electrones/clasificación , Complejo IV de Transporte de Electrones/genética , Variación Genética , Especificidad del Huésped , Interacciones Huésped-Parásitos/fisiología , Myrtaceae/anatomía & histología , Myrtaceae/metabolismo , Filogenia
2.
J Evol Biol ; 30(4): 696-710, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28106948

RESUMEN

Tropical herbivorous insects are astonishingly diverse, and many are highly host-specific. Much evidence suggests that herbivorous insect diversity is a function of host plant diversity; yet, the diversity of some lineages exceeds the diversity of plants. Although most species of herbivorous fruit flies in the Neotropical genus Blepharoneura are strongly host-specific (they deposit their eggs in a single host plant species and flower sex), some species are collected from multiple hosts or flowers and these may represent examples of lineages that are diversifying via changes in host use. Here, we investigate patterns of diversification within six geographically widespread Blepharoneura species that have been collected and reared from at least two host plant species or host plant parts. We use microsatellites to (1) test for evidence of local genetic differentiation associated with different sympatric hosts (different plant species or flower sexes) and (2) examine geographic patterns of genetic differentiation across multiple South American collection sites. In four of the six fly species, we find evidence of local genetic differences between flies collected from different hosts. All six species show evidence of geographic structure, with consistent differences between flies collected in the Guiana Shield and flies collected in Amazonia. Continent-wide analyses reveal - in all but one instance - that genetically differentiated flies collected in sympatry from different host species or different sex flowers are not one another's closest relatives, indicating that genetic differences often arise in allopatry before, or at least coincident with, the evolution of novel host use.


Asunto(s)
Flujo Genético , Simpatría , Tephritidae/genética , Animales , Drosophila , Geografía
3.
J Minim Invasive Gynecol ; 22(6S): S120, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-27678635
4.
J Clin Invest ; 49(1): 170-82, 1970 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-4902826

RESUMEN

Pulmonary blood volume was determined by the radiocardiographic technique in 49 patients coming to cardiac catheterization. Since this method has not been directly compared with the more commonly used double injection of dye. 25 comparisons were carried out in 13 patients of the series. Agreement was good over a range of 4.5-21.1 heart cycles since there was no statistically significant difference between transit time values measured by the two methods. The relation of pulmonary blood volume to other hemodynamic factors in these 49 patients, with and without cardiac or pulmonary disease, was evaluated by means of multiple regression analysis. The analysis carried out for mean transit time indicates that this parameter varies predominately with flow. Pulmonary blood volume, in this series of resting recumbent individuals, varies to a significant degree only with total blood volume and with pulmonary venous pressure. No parameters of vascular distensibility, such as pulmonary vascular resistance, were found to affect the volume of blood in the lungs. The fact that variations in pulmonary blood volume among the subjects could be described by a multiple regression equation linear with respect to total blood volume and pulmonary venous pressure indicates that these variations are the result of passive distention of components of the vascular bed.


Asunto(s)
Determinación del Volumen Sanguíneo , Circulación Pulmonar , Adulto , Anciano , Presión Sanguínea , Cateterismo Cardíaco , Hemodinámica , Humanos , Técnicas de Dilución del Indicador , Matemática , Métodos , Persona de Mediana Edad , Volumen Plasmático , Venas Pulmonares , Resistencia Vascular
5.
J Leukoc Biol ; 69(5): 755-61, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11358984

RESUMEN

Heat shock protein levels are increased in cells as a result of exposure to stress. To determine whether heat shock protein regulation could be used to evaluate stress in cells during spaceflight, the response of Jurkat cells to spaceflight and simulated space shuttle launch vibration was investigated by evaluating hsp70 and hsp27 gene expression. Gene expression was assessed by reverse transcription-polymerase chain reaction using mRNA extracted from vibrated, nonvibrated, space-flown, and ground control cells. Results indicate that mechanical stresses of vibration and low gravity do not up-regulate the mRNA for hsp70, although the gene encoding hsp27 is up-regulated by spaceflight but not by vibration. In ground controls, the mRNA for hsp70 and hsp27 increased with time in culture. We conclude that hsp70 gene expression is a useful indicator of stress related to culture density but is not an indicator of the stresses of launch vibration or microgravity. Up-regulation of hsp27 gene expression in microgravity is a new finding.


Asunto(s)
Regulación de la Expresión Génica , Proteínas HSP70 de Choque Térmico/genética , Proteínas de Choque Térmico , Proteínas de Neoplasias/genética , Vuelo Espacial , Estrés Fisiológico , Vibración/efectos adversos , División Celular , Supervivencia Celular , Proteínas de Choque Térmico HSP27 , Humanos , Células Jurkat , Chaperonas Moleculares , ARN Mensajero , Albúmina Sérica Bovina , Linfocitos T/citología , Linfocitos T/metabolismo , Factores de Tiempo
6.
J Leukoc Biol ; 52(1): 104-10, 1992 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1640164

RESUMEN

Cultured, bone marrow-derived macrophages, murine spleen and lymph node cells, and human lymphocytes were tested for their ability to secrete cytokines in space. Lipopolysaccharide-activated bone marrow macrophages were found to secrete significantly more interleukin-1 and tumor necrosis factor when stimulated in space than when stimulated on earth. Murine spleen cells stimulated with poly I:C in space released significantly more interferon-alpha at 1 and 14 hours after stimulation than cells stimulated on earth. Similarly, murine lymph node T cells and human peripheral blood lymphocytes, stimulated with concanavalin A in space, secreted significantly more interferon-gamma than ground controls. These data suggest that space flight has a significant enhancing effect on immune cell release of cytokines in vitro.


Asunto(s)
Linfocitos B/metabolismo , Citocinas/metabolismo , Macrófagos/metabolismo , Vuelo Espacial , Linfocitos T/metabolismo , Animales , Linfocitos B/citología , Células de la Médula Ósea , Supervivencia Celular , Humanos , Interferón-alfa/metabolismo , Interferón gamma/metabolismo , Interleucina-1/metabolismo , Macrófagos/citología , Ratones , Bazo/citología , Linfocitos T/citología , Factor de Necrosis Tumoral alfa/metabolismo
7.
Gene ; 246(1-2): 81-91, 2000 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-10767529

RESUMEN

A cDNA corresponding to 1-Cys peroxiredoxin, an evolutionarily conserved thiol-specific antioxidant enzyme, was isolated from buckwheat (Fagopyrum esculentum Moench), a dicotyledonous plant species belonging to the Polygonaceae family. The cDNA, which we have designated as FePer1, contains a major open reading frame capable of encoding a polypeptide of 219 residues with a predicted molecular mass of 24.3kDa. The deduced primary structure of FePer1 polypeptide shows a high level (about 70%) of sequence homology to other recently identified plant 1-Cys peroxiredoxins. FePer1 also exhibits a significant level of sequence similarity to non-plant 1-Cys peroxiredoxins, sharing 52 and 42% identities with mammalian and fungal 1-Cys peroxiredoxins, respectively. As for all 1-Cys peroxiredoxins identified from various organisms, the amino acid sequence proposed to constitute the active site of the enzyme is highly conserved in FePer1 polypeptide. The gene corresponding to FePer1 cDNA is a single-copy gene in the buckwheat genome. Its expression is regulated in a seed-specific and temporal manner during seed development. FePer1 gene is induced transiently for a short period immediately after seed imbibition.


Asunto(s)
Fagopyrum/genética , Germinación/genética , Peroxidasas/genética , Semillas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Northern Blotting , Clonación Molecular , Secuencia Conservada , ADN Complementario/química , ADN Complementario/genética , ADN de Plantas/genética , Evolución Molecular , Fagopyrum/enzimología , Fagopyrum/crecimiento & desarrollo , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular , Peroxirredoxinas , Filogenia , Proteínas de Plantas/genética , ARN de Planta/genética , ARN de Planta/metabolismo , Semillas/enzimología , Semillas/crecimiento & desarrollo , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido
8.
J Nucl Med ; 33(4): 512-5, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1552333

RESUMEN

Gallium-67 localizes to the cellular fraction of bronchoalveolar lavage (BAL) fluid in patients with sarcoidosis, idiopathic pulmonary fibrosis, as well as normal subjects. To further study 67Ga disposition in BAL fluid, 11 patients with Pneumocystis carinii pneumonia (PCP) and 8 patients with a variety of other lung diseases, underwent BAL 24 hr after 67Ga injection. Compared to the non-PCP patients, PCP patients had high uptake gallium scans at 24 and 72 hr, and showed significantly increased radioactivity in both unfractionated lavage and in the acellular, supernatant fraction of BAL. The mean ratio of total supernatant/cell pellet radioactivity was also higher in patients with PCP (1.23 +/- 0.27 versus 0.24 +/- 0.05, p less than 0.01). Supernatant radioactivity correlated with the presence of neutrophil alveolitis, but not with BAL transferrin concentrations. We conclude that neutrophil alveolitis in PCP promotes 67Ga accumulation in the acellular fraction of BAL fluid. However, the high uptake 67Ga scans observed in PCP patients without neutrophil alveolitis suggest that the mechanism of pulmonary uptake of 67Ga is not fully elucidated by BAL fluid analysis alone.


Asunto(s)
Líquido del Lavado Bronquioalveolar/metabolismo , Radioisótopos de Galio/farmacocinética , Neumonía por Pneumocystis/diagnóstico por imagen , Adulto , Líquido del Lavado Bronquioalveolar/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Neumonía por Pneumocystis/metabolismo , Cintigrafía
9.
Exp Gerontol ; 35(3): 389-400, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10832058

RESUMEN

Human lymphocytes flown on the Space Shuttle respond poorly to mitogen stimulation and populations of the lymphoblastoid T cell line, Jurkat, manifest growth arrest, increase in apoptosis and time- and microgravity-dependent increases in the soluble form of the cell death factor, Fas/APO-1 (sFas). The potential role of apoptosis in population dynamics of space-flown lymphocytes has not been investigated previously. We flew Jurkat cells on Space Transportation System (STS)-80 and STS-95 to determine whether apoptosis and the apparent microgravity-related release of sFas are characteristic of lymphocytes in microgravity. The effects of spaceflight and ground-based tests simulating spaceflight experimental conditions, including high cell density and low serum concentration, were assessed. Immunofluorescence microscopy showed increased cell associated Fas in flown cells. Results of STS-80 and STS-95 confirmed increase in apoptosis during spaceflight and the release of sFas as a repeatable, time-dependent and microgravity-related response. Ground-based tests showed that holding cells at 1.5 million/ml in medium containing 2% serum before launch did not increase sFas. Reports of increased Fas in cells of the elderly and the increases in spaceflown cells suggest possible similarities between aging and spaceflight effects on lymphocytes.


Asunto(s)
Linfocitos/inmunología , Ingravidez/efectos adversos , Receptor fas/metabolismo , Envejecimiento/inmunología , Apoptosis , Recuento de Células , División Celular , Medios de Cultivo , Humanos , Células Jurkat , Linfocitos/citología , Vuelo Espacial
10.
Chest ; 93(1): 60-4, 1988 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-3257184

RESUMEN

We correlated bronchoalveolar lavage (BAL) cell populations with clinical course and outcome in 19 patients with Pneumocystis carinii pneumonia and acquired immunodeficiency syndrome. Twelve patients demonstrated an elevated (greater than or equal to 5 percent) BAL combined neutrophil and eosinophil count, which correlated with the magnitude of the alveolar-arterial PO2 gradient. Patients with elevated BAL granulocytes also had significantly higher serum lactate dehydrogenase levels. Three of the four patients who died had the highest percentage of neutrophil counts observed in lavage fluid. Although no patient was thought to have a concurrent bacterial infection, potential pathogens were cultured from the sputum of patients with the most elevated neutrophil counts. Whether BAL granulocytes reflect an inflammatory process analogous to the adult respiratory distress syndrome or signify concomitant bacterial infection remains to be determined. We conclude that BAL granulocytes are associated with more severe respiratory compromise in patients with Pneumocystis carinii pneumonia.


Asunto(s)
Líquido del Lavado Bronquioalveolar/citología , Neumonía por Pneumocystis/patología , Síndrome de Inmunodeficiencia Adquirida/patología , Adulto , Recuento de Células , Eosinófilos/patología , Humanos , L-Lactato Deshidrogenasa/sangre , Linfocitos/patología , Macrófagos/patología , Persona de Mediana Edad , Neutrófilos/patología , Oxígeno/sangre , Neumonía por Pneumocystis/sangre , Pronóstico , Factores de Riesgo
11.
Chest ; 93(5): 987-92, 1988 May.
Artículo en Inglés | MEDLINE | ID: mdl-3258807

RESUMEN

We investigated the source of elevated serum lactate dehydrogenase (LDH) levels in seven patients with Pneumocystis carinii pneumonia (PCP) by analyzing blood and bronchoalveolar lavage (BAL) albumin (ALB) and LDH, with isoenzyme fractionation. Four patients with non-PCP lung disease served as control subjects. In PCP patients, BAL LDH was sixfold higher, and BAL ALB, fourfold higher than in the non-PCP patients. The increased LDH/ALB in BAL as compared to serum, in addition to a BAL isoenzyme pattern characteristic of lung, suggest that BAL LDH arises from a pulmonary source. We postulate that the high correlation observed between BAL and serum LDH (r = 0.93, p less than 0.001) reflects backflow of pulmonary-derived LDH into the blood through an alveolocapillary membrane (ACM) compromised by PCP. Furthermore, a comparison of BAL LDH/ALB for each isoenzyme with the same serum ratio showed less backflow for the cationic isoenzymes. The ACM appears to sieve proteins on an electrical basis which may account for the LDH isomorphic pattern observed in the serum of PCP patients.


Asunto(s)
L-Lactato Deshidrogenasa/análisis , Neumonía por Pneumocystis/enzimología , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Adulto , Líquido del Lavado Bronquioalveolar/enzimología , Permeabilidad Capilar , Humanos , Isoenzimas , Masculino , Neumonía por Pneumocystis/etiología , Factores de Riesgo , Albúmina Sérica/análisis
12.
Chest ; 96(4): 857-61, 1989 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2791685

RESUMEN

The Acute Physiology and Chronic Health Evaluation (APACHE) II classification, a measure of severity of illness in patients requiring intensive care, was devised before the rapid expansion of the acquired immunodeficiency syndrome (AIDS) epidemic. To determine the applicability of the APACHE II system to AIDS, we related observed in-hospital death rates to those predicted by APACHE II in 83 patients with AIDS. In a control group of patients without AIDS (n = 166) mean predicted and observed death rates (34.1 vs 31.3 percent) were similar. For the AIDS group overall observed mortality (63.9 percent) was significantly greater than that predicted by APACHE II (45.8 percent). The subgroup with Pneumocystis pneumonia requiring mechanical ventilation (n = 37) had an observed mortality (86.5 percent) that significantly exceeded the predicted value (44.3 percent), whereas all other AIDS patients (n = 46) showed similar predicted and observed death rates (47.0 vs 45.7 percent). APACHE II prediction of death rate also matched observed mortality in mechanically ventilated patients without Pneumocystis infection. The discrepancy between predicted and observed mortality in patients with Pneumocystis pneumonia requiring mechanical ventilation is most likely due to the lack of an APACHE II diagnostic category that accurately reflects the severity of this disease. A new diagnostic category that provides accurate outcome prediction in this patient group would form a basis for evaluation of new therapeutic interventions.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/mortalidad , Unidades de Cuidados Intensivos , Índice de Severidad de la Enfermedad , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Humanos , Admisión del Paciente , Neumonía por Pneumocystis/complicaciones , Neumonía por Pneumocystis/mortalidad , Pronóstico , Análisis de Regresión , Análisis de Supervivencia
13.
Chest ; 102(1): 143-6, 1992 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1623742

RESUMEN

The present study was undertaken to clarify the role of bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB) in the diagnosis of pulmonary tuberculosis in patients at risk for human immunodeficiency virus (HIV) infection. We retrospectively identified 31 patients at risk for HIV who proved to have Mycobacterium tuberculosis on culture of at least one pulmonary specimen. All had pulmonary symptoms but initial sputum smears negative for acid-fast bacilli (AFB). All underwent fiberoptic bronchoscopy (FOB), including BAL and TBB; postbronchoscopy sputum was also collected in 19 patients. A specimen was considered to yield an immediate diagnosis when positive for AFB either on smear or histologic study; granulomas alone were considered positive when no other causes were identified. Overall, an immediate diagnosis was made by bronchoscopic specimens in 15 (48 percent) of 31 cases. TBB was the sole positive specimen in seven patients (23 percent). For comparison, similar specimens from 40 patients in whom M avium complex (MAC) grew on culture were also evaluated. An immediate identification of AFB was made in only four patients (10 percent). We conclude that the finding of AFB on staining of any pulmonary specimen is highly suggestive of tuberculosis, rather than MAC, and warrants institution of antituberculosis therapy. Of all bronchoscopic specimens, TBB provides the highest yield for an immediate diagnosis of tuberculosis.


Asunto(s)
Broncoscopía , Infecciones por VIH/complicaciones , Tuberculosis Pulmonar/diagnóstico , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Adulto , Biopsia , Infecciones por VIH/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Complejo Mycobacterium avium/aislamiento & purificación , Infección por Mycobacterium avium-intracellulare/complicaciones , Infección por Mycobacterium avium-intracellulare/diagnóstico , Mycobacterium tuberculosis/aislamiento & purificación , Factores de Riesgo , Irrigación Terapéutica , Tuberculosis Pulmonar/complicaciones , Tuberculosis Pulmonar/microbiología
14.
Arch Ophthalmol ; 96(4): 620-4, 1978 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-646687

RESUMEN

Twenty-one patients under age 55 had idiopathic serous detachments of the retinal pigment epithelium (rpe) one-fifth disc diameter or larger in size. In the absence of other choroidal diseases, such as senile mascular degeneration, presumed ocular histoplasmosis syndrome, or anglioid streaks, serous RPE detachments have a good prognosis and probably are a variant of idiopathic central serous choroidopathy. The presence of associated subretinal fluid involving the macula was the factor that had the most effect on visual acuity. Serous detachments of the RPE should be distinguished from multiple vitelliform lesions (a variant of vitelliform dystrophy).


Asunto(s)
Epitelio Pigmentado Ocular/patología , Desprendimiento de Retina/patología , Adulto , Espacio Extracelular , Femenino , Angiografía con Fluoresceína , Humanos , Masculino , Persona de Mediana Edad , Agudeza Visual
15.
Arch Ophthalmol ; 93(5): 343-6, 1975 May.
Artículo en Inglés | MEDLINE | ID: mdl-1170834

RESUMEN

In six patients with aphakic pupillary block, argon laser produced full-thickness iridotomies that succeeded in restoring anterior chamber and intraocular pressure to normal. In one case, it was shown that location of iridotomy is important in determining whether or not iridotomy will succeed in relieving aphakic pupillary block. In two cases, pupillary block had resulted in shallowing of the anterior chamber without pressure elevation. Cases reported here show that continuous laser energy, such as from an argon laser, can produce a full-thickness opening, in contrast to the short duration pulse of the ruby, which will destroy only pigmented structures without producing a full-thickness iris opening. This need to produce some degree of spread of damage to unpigmented tissue elements in order to achieve and iris opening is a problem in phakic patients where injury to the lens must be avoided.


Asunto(s)
Extracción de Catarata , Glaucoma/cirugía , Iris/cirugía , Terapia por Láser , Rayos Láser/métodos , Pupila , Anciano , Argón , Oftalmopatías/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Adherencias Tisulares , Cuerpo Vítreo/cirugía
16.
Arch Ophthalmol ; 96(2): 263-7, 1978 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-629673

RESUMEN

A case is describes in which the earliest clinical manifestations of sympathetic uveitis that occurred after trauma and pars plana vitrectomy were confined primarily to the retina, retinal pigment epithelium, and choroid posteriorly, and resembled focal lesions of acute posterior multifocal placoid pigment epitheliopathy. Similar focal lesions were noted on gross examination of the enucleated inciting eye. Histopathological examination revealed that these lesions were caused by focal choroidal granulomas and overlying Dalen-Fuchs nodules. Sympathetic ophthalmia was also noted in four other patients in whom the condition developed after trauma and vitrectomy.


Asunto(s)
Lesiones Oculares/complicaciones , Oftalmía Simpática , Complicaciones Posoperatorias , Cuerpo Vítreo/cirugía , Heridas no Penetrantes/complicaciones , Adulto , Coroiditis/complicaciones , Ojo/patología , Lesiones Oculares/cirugía , Femenino , Angiografía con Fluoresceína , Granuloma/complicaciones , Granuloma/etiología , Humanos , Masculino , Persona de Mediana Edad , Oftalmía Simpática/diagnóstico , Oftalmía Simpática/etiología , Degeneración Retiniana/complicaciones , Degeneración Retiniana/etiología , Síndrome , Enfermedades de la Úvea/complicaciones , Enfermedades de la Úvea/etiología , Heridas no Penetrantes/cirugía
17.
Arch Ophthalmol ; 111(6): 789-94, 1993 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7685589

RESUMEN

OBJECTIVE: We undertook a retrospective study of all choroidal nevi with overlying neovascularization seen at Bascom Palmer Eye Institute, Miami, Fla, to determine long-term effects on vision and whether the presence of neovascularization represented increased malignant potential of the lesion. DESIGN: A computer search of patients with a coded diagnosis of both a choroidal nevus and choroidal neovascularization was performed. Cases in which the neovascularization was directly overlying the nevus were used for the study. RESULTS: The records of 23 patients followed up for a mean of 6.5 years were reviewed for visual acuity, effect of treatment, and change in the size of the choroidal lesion. Fifteen of the 23 patients had a final visual acuity in the affected eye of 20/200 or better. Five of six patients treated with laser had visual improvement of 2 or more lines. Only one of these lesions showed any growth, and this was after 17 years of no growth. CONCLUSIONS: Choroidal neovascularization associated with choroidal nevi can have profound effects on vision. Laser treatment, when indicated, is effective and may be safely performed. The clinical course of these lesions, to date, does not indicate any clinically significant malignant transformation.


Asunto(s)
Neoplasias de la Coroides/complicaciones , Coroides/irrigación sanguínea , Neovascularización Patológica/complicaciones , Nevo Pigmentado/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Coroides/patología , Neoplasias de la Coroides/patología , Femenino , Angiografía con Fluoresceína , Estudios de Seguimiento , Fondo de Ojo , Humanos , Coagulación con Láser , Masculino , Persona de Mediana Edad , Neovascularización Patológica/patología , Neovascularización Patológica/cirugía , Nevo Pigmentado/patología , Estudios Retrospectivos , Agudeza Visual
18.
J Clin Pathol ; 27(3): 242-6, 1974 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-4832304

RESUMEN

Severe cyclic thrombocytopenia is reported in a young woman. This rare phenomenon is of considerable theoretical interest in relation to platelet kinetics. In this patient platelet and fibrinogen survival times exclude the possibility of excessive peripheral platelet destruction. Serial plasma thrombopoietin levels suggest that a deficiency of this protein may be the underlying factor. As a result platelet production may fall to a very low level. The megakaryocyte, however, remains responsive and the hypothesis advanced is that under these circumstances the intermenstrual platelet increase, normally caused by the interplay of the sex hormones, becomes grossly exaggerated.


Asunto(s)
Plaquetas , Ritmo Circadiano , Trombocitopenia/metabolismo , Adulto , Trastornos de las Proteínas Sanguíneas/metabolismo , Transfusión Sanguínea , Castración , Radioisótopos de Cromo , Femenino , Fibrinógeno/metabolismo , Humanos , Histerectomía , Radioisótopos de Yodo , Megacariocitos , Trastornos de la Menstruación , Trombopoyetina/metabolismo , Factores de Tiempo
19.
J Appl Physiol (1985) ; 76(3): 1363-71, 1994 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8005883

RESUMEN

The distribution function of pulmonary transit times (fPTT) defines contact time between blood and vascular bed, which affects gas exchange and endothelial metabolic functions. This study was undertaken to assess effects of abnormal pulmonary inflow (PPA) and outflow pressures (PLA) on fPTT. Three groups were studied: five patients with elevated PLA and passive pulmonary hypertension (LVD-Ab), eight with normal PLA (LVD-Nl), and six with pulmonary disease and various levels of PPA (PD). Empirical complex exponential functions were convoluted on right and left ventricular indicator-dilution curves to derive fPTT; mean transit time (Mo1), standard deviation (Sm2), and cube root of the third moment about Mo1 (Sm3) were calculated by standard equations. A single linear regression of Sm3 and Sm2 on Mo1 was observed for all patients, regardless of disease process. Inverse relations between Mo1, Sm2, and Sm3 and blood flow were highly significant, but dispersion volumes (DV = Mo1 x flow) were higher in patients with elevated PPA. Significant linear regressions of fPTT parameters on PPA, derived in LVD-Nl and LVD-Ab patients, failed to predict Mo1, Sm2, and Sm3 for the PD group, whereas linear regressions on PLA accurately predicted Mo1, Sm2, and Sm3 in the PD group. Relations between fPTT parameters and PLA were equally well fit by exponential equations in all 19 patients, consistent with an asymptotic pressure-volume relation of distensible vessels. Microvascular pressure (PMV), combining PPA and PLA, was not a better predictor of fPTT parameters in LVD-NL and LVD-Ab patients but provided a slightly closer estimate of relative dispersion and skewness in PD patients.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Presión Sanguínea/fisiología , Circulación Pulmonar/fisiología , Adulto , Cateterismo Cardíaco , Gasto Cardíaco/fisiología , Hemodinámica/fisiología , Humanos , Hipertensión Pulmonar/fisiopatología , Técnicas de Dilución del Indicador , Enfermedades Pulmonares/fisiopatología , Masculino , Microcirculación/fisiología , Persona de Mediana Edad , Pruebas de Función Respiratoria , Posición Supina/fisiología
20.
Brain Res ; 626(1-2): 295-302, 1993 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-8281438

RESUMEN

Altered cardiovascular function in status epilepticus may contribute to mortality and morbidity in patients. We investigated changes in cardiac output and regional hemodynamics during 2 h of recurrent PTZ-induced seizures in anesthetized, paralyzed rats using radioactive microspheres, thermodilution methods, and the pulsed Doppler technique. Cardiac output fell 30-60% during recurrent seizures in 17 of 27 animals. The fall in cardiac output was sudden in onset and occurred primarily in association with seizures accompanied by prolonged increases in MABP but no change in central venous pressure. Total peripheral resistance (TPR) rose during early seizures in association with vasoconstriction of renal and certain splanchnic vascular beds. Ictal increases in TPR became attenuated during late seizures, due to failure of renal and splanchnic beds to constrict. Therefore, derangements in both cardiac and vascular function occur during late seizures. These derangements may contribute to both cerebral hypoperfusion and sudden death in status epilepticus.


Asunto(s)
Gasto Cardíaco , Hemodinámica/fisiología , Convulsiones/fisiopatología , Estado Epiléptico/fisiopatología , Animales , Presión Sanguínea/fisiología , Masculino , Ratas , Ratas Wistar , Resistencia Vascular/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA