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1.
Campbell Syst Rev ; 15(3): e1052, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37131518

RESUMEN

The objective of the review is to use individual participant data (IPD) meta-analysis to explore the effect of mass deworming during pregnancy. We developed a search strategy and searched the databases till March 2018. We included individually randomised controlled trials; cluster randomised controlled trials and quasi randomised studies providing preventive or therapeutic deworming drugs for soil transmitted helminthiases and schistosomiasis during pregnancy. All IPD were assessed for completeness, compared to published reports and entered into a common data spreadsheet. Out of the seven trials elgible for IPD, we received data from three trials; out of 8,515 potential IPD participants; data were captured for 5,957 participants. Findings from this IPD suggest that mass deworming during pregnancy reduces maternal anaemia by 23% (Risk ratio [RR]: 0.77, 95% confidence intreval [CI]: 0.73-0.81; three trials; 5,216 participants; moderate quality evidence). We did not find any evidence of an effect of mass deworming during pregnancy on any of the other outcomes. There was no evidence of effect modification; however these findings should be interpreted with caution due to small sample sizes. The quality of evidence was rated as moderate for our findings. Our analyses suggest that mass deworming during pregnancy is associated with reducing anaemia with no evidence of impact on any other maternal or pregnancy outcomes. Our analyses were limited by the availability of data for the impact by subgroups and effect modification. There is also a need to support and promote open data for future IPDs.

2.
Nature ; 491(7422): 79-82, 2012 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-23128227

RESUMEN

The surface of the asteroid Vesta has prominent near-infrared absorption bands characteristic of a range of pyroxenes, confirming a direct link to the basaltic howardite-eucrite-diogenite class of meteorites. Processes active in the space environment produce 'space weathering' products that substantially weaken or mask such diagnostic absorption on airless bodies observed elsewhere, and it has long been a mystery why Vesta's absorption bands are so strong. Analyses of soil samples from both the Moon and the asteroid Itokawa determined that nanophase metallic particles (commonly nanophase iron) accumulate on the rims of regolith grains with time, accounting for an observed optical degradation. These nanophase particles, believed to be related to solar wind and micrometeoroid bombardment processes, leave unique spectroscopic signatures that can be measured remotely but require sufficient spatial resolution to discern the geologic context and history of the surface, which has not been achieved for Vesta until now. Here we report that Vesta shows its own form of space weathering, which is quite different from that of other airless bodies visited. No evidence is detected on Vesta for accumulation of lunar-like nanophase iron on regolith particles, even though distinct material exposed at several fresh craters becomes gradually masked and fades into the background as the craters age. Instead, spectroscopic data reveal that on Vesta a locally homogenized upper regolith is generated with time through small-scale mixing of diverse surface components.

3.
Nature ; 413(6854): 390-3, 2001 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-11574879

RESUMEN

The NEAR-Shoemaker spacecraft was designed to provide a comprehensive characterization of the S-type asteroid 433 Eros (refs 1,2,3), an irregularly shaped body with approximate dimensions of 34 x 13 x 13 km. Following the completion of its year-long investigation, the mission was terminated with a controlled descent to its surface, in order to provide extremely high resolution images. Here we report the results of the descent on 12 February 2001, during which 70 images were obtained. The landing area is marked by a paucity of small craters and an abundance of 'ejecta blocks'. The properties and distribution of ejecta blocks are discussed in a companion paper. The last sequence of images reveals a transition from the blocky surface to a smooth area, which we interpret as a 'pond'. Properties of the 'ponds' are discussed in a second companion paper. The closest image, from an altitude of 129 m, shows the interior of a 100-m-diameter crater at 1-cm resolution.

4.
Science ; 292(5516): 484-8, 2001 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-11313490

RESUMEN

On 25 October 2000, the Near Earth Asteroid Rendevous (NEAR)-Shoemaker spacecraft executed a low-altitude flyover of asteroid 433 Eros, making it possible to image the surface at a resolution of about 1 meter per pixel. The images reveal an evolved surface distinguished by an abundance of ejecta blocks, a dearth of small craters, and smooth material infilling some topographic lows. The subdued appearance of craters of different diameters and the variety of blocks and different degrees of their burial suggest that ejecta from several impact events blanketed the region imaged at closest approach and led to the building up of a substantial and complex regolith consisting of fine materials and abundant meter-sized blocks.

5.
Arch Pathol Lab Med ; 122(10): 912-4, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9786353

RESUMEN

BACKGROUND: Although colon carcinomas consisting predominantly of neuroendocrine cells carry a worse prognosis than "routine" colon adenocarcinomas, the clinical significance of scattered neoplastic neuroendocrine cells within a typical colon adenocarcinoma remains controversial. The aim of this study was to document the frequency and clinical significance of neuroendocrine cell expression within a stage-specific group of typical adenocarcinomas of the colon. METHODS: Forty-eight patients with resected stage III adenocarcinomas of the colon were selected from our institutional tumor registry. The pathologic specimens from these patients were reviewed and underwent immunohistochemical staining for chromogranin, a sensitive and specific marker of neuroendocrine differentiation. Long-term (> or = 5 years) clinical outcome was compared with the presence of neuroendocrine cell expression. RESULTS: Twenty tumors (41.7%) stained positively for chromogranin. Twenty-two patients (45.8%) had long-term cancer-free survival, although chromogranin positivity did not correlate with this survival. CONCLUSION: The frequency of scattered neuroendocrine cells within colonic adenocarcinomas is high. This finding does not, however, carry the same adverse prognostic implications for cancer survival as does the presence of true neuroendocrine carcinoma of the colon.


Asunto(s)
Adenocarcinoma/patología , Neoplasias del Colon/patología , Tumores Neuroendocrinos/patología , Biomarcadores de Tumor , Diferenciación Celular/fisiología , Femenino , Humanos , Masculino , Estadificación de Neoplasias , Sensibilidad y Especificidad , Resultado del Tratamiento
6.
Am J Surg Pathol ; 22(8): 1020-5, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9706983

RESUMEN

A clear cell variant of primary pulmonary carcinoid tumor is described. The tumor arose in a 53-year-old woman who was incidentally found to have a solitary pulmonary nodule in the left upper lobe during routine chest roentgenography. Histologically, the tumor was composed of predominantly clear to lightly eosinophilic, polygonal cells with bland nuclei arranged in sheets and nests. Nuclear pleomorphism, necrosis, vascular invasion, and mitotic figures were not seen. The tumor cells were negative for oil-red-O and periodic acid-Schiff stains with and without diastase pretreatment on frozen and formalin-fixed sections, respectively. During immunohistochemical evaluation, the tumor cells were focally positive for cytokeratin and diffusely positive for neuron-specific enolase and chromogranin. Electron microscopy performed on paraffin block-retrieved tissue showed the presence of electron-dense, neurosecretory-type granules and variably sized vacuolated areas within the cytoplasm. the nature of which remained unclear. Intracytoplasmic glycogen or lipid were not identified. To our knowledge, this is the first report of pulmonary clear cell carcinoid tumor.


Asunto(s)
Tumor Carcinoide/patología , Neoplasias Pulmonares/patología , Tumor Carcinoide/metabolismo , Tumor Carcinoide/cirugía , Diagnóstico Diferencial , Femenino , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/cirugía , Microscopía Electrónica , Persona de Mediana Edad
7.
Ann Surg ; 227(6): 841-50, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9637547

RESUMEN

OBJECTIVE: The goals were to summarize the results of liver transplantation for chronic hepatitis B disease (HBV) at the University of Virginia, correlate pretransplant viral markers with posttransplant hepatitis B immunoglobulin (HBIg) requirements, and identify the relation between viral protein in the liver and clinical reinfection. SUMMARY BACKGROUND DATA: Liver transplantation is an accepted treatment for end-stage liver disease from chronic HBV infection, although lifelong antiviral treatment (with HBIg or antiviral agents) is still necessary. Patients with evidence of active viral replication (detectable serum HBV-DNA or e antigen) at the time of transplant have a higher rate of allograft infection. Whether clinically stable patients receiving HBIg immunoprophylaxis have detectable viral products in their grafts remains unknown. METHODS: Forty-four transplants performed for HBV disease at the University of Virginia since March 1990 were reviewed. Most patients underwent aggressive passive immunoprophylaxis with HBIg to maintain serum HBV surface antibody (HBsAb) levels > or =500 IU/l for the first 6 months after the transplant, and > or =150 IU/l thereafter. Patients had viral markers quantified, underwent pharmacokinetic analysis of HBsAb levels to adjust dosing, and were biopsied routinely every 3 to 6 months and when indicated. RESULTS: Forty-four transplants were performed in 39 patients. Actual 1-year and 3-year graft survival was 95% and 81%, respectively, and 1-year and 3-year patient survival was 98% and 96%, respectively. After the adoption of indefinite HBIg prophylaxis, nine grafts became infected (all in recipients positive for HBV e antigen). Three occurred within 8 weeks of transplantation and were associated with a short HBsAb half-life and a wild-type virus. Six occurred >8 months after the transplant, and most of these were associated with viral mutation. Quantification of pretransplant markers was an overall poor predictor of HBIg requirements after the transplant. Immunohistochemistry demonstrated transient low-level expression of core protein in the liver in 23% of patients without serum or clinical evidence of recurrent hepatitis. CONCLUSIONS: An excellent outcome is possible after liver transplantation for chronic HBV disease using HBIg dosed by pharmacokinetic parameters. Currently, quantification of pretransplant serum markers of the HBV antigen load does not predict the intensity of posttransplant treatment required for good clinical outcomes. Because HBV is not eradicated from the patient, some form of indefinite antiviral therapy continues to be warranted.


Asunto(s)
Antígenos de la Hepatitis B/sangre , Hepatitis B/complicaciones , Inmunización Pasiva/métodos , Fallo Hepático/cirugía , Fallo Hepático/virología , Trasplante de Hígado , Adulto , Anciano , Enfermedad Crónica , ADN Viral/sangre , Femenino , Rechazo de Injerto , Supervivencia de Injerto , Hepatitis B/genética , Hepatitis B/inmunología , Antígenos de Superficie de la Hepatitis B/sangre , Antígenos e de la Hepatitis B/sangre , Humanos , Fallo Hepático/inmunología , Masculino , Persona de Mediana Edad , Análisis de Supervivencia , Resultado del Tratamiento
10.
Semin Diagn Pathol ; 14(3): 213-9, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9279977

RESUMEN

Clear cell neoplasms of the abdominal organs are represented by a variety of epithelial and mesenchymal neoplasms, of varying malignant potential. Several varieties of clear cell carcinomas, including those with tubulopapillary, hepatoid, colloid, or neuroendocrine features, have been described, as well as several benign epithelial neoplasms. These epithelial tumors have been reported in the gastrointestinal hollow viscera, as well as the liver, pancreas, and biliary tract. A second major consideration is the mesenchymal-derived gastrointestinal stromal tumors, which also may feature clear cells, and comprise a spectrum of biological behavior. Miscellaneous lesions include clear cell variants of melanoma and mesothelioma. This review includes histological details of the various entities, as well as important histochemical, immunohistological, and ultrastructural features. Pertinent differential diagnostic points are stressed, including distinction of the primary clear lesions from relevant metastatic neoplasms.


Asunto(s)
Neoplasias Abdominales/patología , Adenocarcinoma de Células Claras/patología , Neoplasias Intestinales/patología , Anciano , Humanos , Masculino , Melanoma/patología , Melanoma/secundario , Mesodermo/patología , Mesotelioma/patología
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