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1.
J Magn Reson Imaging ; 2024 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-39133767

RESUMEN

The role of MRI to estimate liver iron concentration (LIC) for identifying patients with iron overload and guiding the titration of chelation therapy is increasingly established for routine clinical practice. However, the existence of multiple MRI-based LIC quantification techniques limits standardization and widespread clinical adoption. In this article, we review the existing and widely accepted MRI-based LIC estimation methods at 1.5 T and 3 T: signal intensity ratio (SIR) and relaxometry (R2 and R2*) and discuss the basic principles, acquisition and analysis protocols, and MRI-LIC calibrations for each technique. Further, we provide an up-to-date information on MRI vendor implementations and available offline commercial and free software for each MRI-based LIC quantification approach. We also briefly review the emerging and advanced MRI techniques for LIC estimation and their current limitations for clinical use. Lastly, we discuss the implications of MRI-based LIC measurements on clinical use and decision-making in the management of patients with iron overload. Some of the key highlights from this review are as follows: 1) Both R2 and R2* can estimate accurate and reproducible LIC, when validated acquisition parameters and analysis protocols are applied, 2) Although the Ferriscan R2 method has been widely used, recent consensus and guidelines endorse R2*-MRI as the most accurate and reproducible method for LIC estimation, 3) Ongoing efforts aim to establish R2*-MRI as the standard approach for quantifying LIC, and 4) Emerging R2*-MRI techniques employ radial sampling strategies and offer improved motion compensation and broader dynamic range for LIC estimation. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

2.
Nano Lett ; 18(6): 3481-3487, 2018 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-29701991

RESUMEN

Electric and magnetic optical fields carry the same amount of energy. Nevertheless, the efficiency with which matter interacts with electric optical fields is commonly accepted to be at least 4 orders of magnitude higher than with magnetic optical fields. Here, we experimentally demonstrate that properly designed photonic nanoantennas can selectively manipulate the magnetic versus electric emission of luminescent nanocrystals. In particular, we show selective enhancement of magnetic emission from trivalent europium-doped nanoparticles in the vicinity of a nanoantenna tailored to exhibit a magnetic resonance. Specifically, by controlling the spatial coupling between emitters and an individual nanoresonator located at the edge of a near-field optical scanning tip, we record with nanoscale precision local distributions of both magnetic and electric radiative local densities of states (LDOS). The map of the radiative LDOS reveals the modification of both the magnetic and electric quantum environments induced by the presence of the nanoantenna. This manipulation and enhancement of magnetic light-matter interaction by means of nanoantennas opens up new possibilities for the research fields of optoelectronics, chiral optics, nonlinear and nano-optics, spintronics, and metamaterials, among others.

3.
Comput Biol Med ; 174: 108448, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38626508

RESUMEN

BACKGROUND AND OBJECTIVE: Magnetic resonance imaging (MRI) has emerged as a noninvasive clinical tool for assessment of hepatic steatosis. Multi-spectral fat-water MRI models, incorporating single or dual transverse relaxation decay rate(s) (R2*) have been proposed for accurate fat fraction (FF) estimation. However, it is still unclear whether single- or dual-R2* model accurately mimics in vivo signal decay for precise FF estimation and the impact of signal-to-noise ratio (SNR) on each model performance. Hence, this study aims to construct virtual steatosis models and synthesize MRI signals with different SNRs to systematically evaluate the accuracy of single- and dual-R2* models for FF and R2* estimations at 1.5T and 3.0T. METHODS: Realistic hepatic steatosis models encompassing clinical FF range (0-60 %) were created using morphological features of fat droplets (FDs) extracted from human liver biopsy samples. MRI signals were synthesized using Monte Carlo simulations for noise-free (SNRideal) and varying SNR conditions (5-100). Fat-water phantoms were scanned with different SNRs to validate simulation results. Fat water toolbox was used to calculate R2* and FF for both single- and dual-R2* models. The model accuracies in R2* and FF estimates were analyzed using linear regression, bias plot and heatmap analysis. RESULTS: The virtual steatosis model closely mimicked in vivo fat morphology and Monte Carlo simulation produced realistic MRI signals. For SNRideal and moderate-high SNRs, water R2* (R2*W) by dual-R2* and common R2* (R2*com) by single-R2* model showed an excellent agreement with slope close to unity (0.95-1.01) and R2 > 0.98 at both 1.5T and 3.0T. In simulations, the R2*com-FF and R2*W-FF relationships exhibited slopes similar to in vivo calibrations, confirming the accuracy of our virtual models. For SNRideal, fat R2* (R2*F) was similar to R2*W and dual-R2* model showed slightly higher accuracy in FF estimation. However, in the presence of noise, dual-R2* produced higher FF bias with decreasing SNR, while leading to only marginal improvement for high SNRs and in regions dominated by fat and water. In contrast, single-R2* model was robust and produced accurate FF estimations in simulations and phantom scans with clinical SNRs. CONCLUSION: Our study demonstrates the feasibility of creating virtual steatosis models and generating MRI signals that mimic in vivo morphology and signal behavior. The single-R2* model consistently produced lower FF bias for clinical SNRs across entire FF range compared to dual-R2* model, hence signifying that single-R2* model is optimal for assessing hepatic steatosis.


Asunto(s)
Hígado Graso , Imagen por Resonancia Magnética , Humanos , Imagen por Resonancia Magnética/métodos , Hígado Graso/diagnóstico por imagen , Relación Señal-Ruido , Hígado/diagnóstico por imagen , Hígado/metabolismo , Simulación por Computador , Método de Montecarlo , Masculino , Modelos Biológicos , Tejido Adiposo/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Femenino
4.
Cureus ; 16(1): e52985, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38406044

RESUMEN

Venous thromboembolism (VTE) is a common disease, which includes deep venous thrombosis (DVT) and pulmonary embolism (PE). It is the third most common cardiovascular disorder, affecting predominantly the male elderly population. Stress cardiomyopathy (SC) is a transitorily cardiovascular condition produced after an emotional or physical trigger, and it features signs and symptoms of acute coronary syndrome. Its pathophysiological mechanisms remain unclear, and SC has also been related to critical complications such as heart failure, arrhythmias, left ventricular outflow obstruction, and thromboembolic events. This case report highlights the association of PE and SC that might play a pathophysiological role.

5.
Cancers (Basel) ; 16(2)2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-38254804

RESUMEN

Traditional microbiological methodology is valuable and essential for microbiota composition description and microbe role assignations at different anatomical sites, including cervical and vaginal tissues; that, combined with molecular biology strategies and modern identification approaches, could give a better perspective of the microbiome under different circumstances. This pilot work aimed to describe the differences in microbiota composition in non-cancer women and women with cervical cancer through a culturomics approach combining culture techniques with Vitek mass spectrometry and 16S rDNA sequencing. To determine the possible differences, diverse statistical, diversity, and multivariate analyses were applied; the results indicated a different microbiota composition between non-cancer women and cervical cancer patients. The Firmicutes phylum dominated the non-cancer (NC) group, whereas the cervical cancer (CC) group was characterized by the predominance of Firmicutes and Proteobacteria phyla; there was a depletion of lactic acid bacteria, an increase in the diversity of anaerobes, and opportunistic and non-typical human microbiota isolates were present. In this context, we hypothesize and propose a model in which microbial composition and dynamics may be essential for maintaining the balance in the cervical microenvironment or can be pro-oncogenesis microenvironmental mediators in a process called Ying-Yang or have a protagonist/antagonist microbiota role.

6.
J Clin Exp Hepatol ; 13(3): 468-478, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37250872

RESUMEN

Background/objectives: Prevalence of nonalcoholic fatty liver disease (NAFLD) has increased to 25% of the world population. Hepatic steatosis is a hallmark feature of NAFLD and is assessed histologically using visual and ordinal fat grading criteria (0-3) from the Nonalcoholic Steatohepatitis (NASH) Clinical Research Network (CRN) scoring system. The purpose of this study is to automatically segment and extract morphological characteristics and distributions of fat droplets (FDs) on liver histology images and find associations with severity of steatosis. Methods: A previously published human cohort of 68 NASH candidates was graded for steatosis by an experienced pathologist using the Fat CRN grading system. The automated segmentation algorithm quantified fat fraction (FF) and fat-affected hepatocyte ratio (FHR), extracted fat morphology by calculating radius and circularity of FDs, and examined FDs distribution and heterogeneity using nearest neighbor distance and regional isotropy. Results: Regression analysis and Spearman correlation (ρ) yielded high correlations for radius (R2 = 0.86, ρ = 0.72), nearest neighbor distance (R2 = 0.82, ρ = -0.82), regional isotropy (R2 = 0.84, ρ = 0.74), and FHR (R2 = 0.90, ρ = 0.85), and low correlation for circularity (R2 = 0.48, ρ = -0.32) with FF and pathologist grades, respectively. FHR showed a better distinction between pathologist Fat CRN grades compared to conventional FF measurements, making it a potential surrogate measure for Fat CRN scores. Our results showed variation in distribution of morphological features and steatosis heterogeneity within the same patient's biopsy sample as well as between patients of similar FF. Conclusions: The fat percentage measurements, specific morphological characteristics, and patterns of distribution quantified with the automated segmentation algorithm showed associations with steatosis severity; however, future studies are warranted to evaluate the clinical significance of these steatosis features in progression of NAFLD and NASH.

7.
Cureus ; 15(10): e46802, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37954753

RESUMEN

Background Acute coronary syndrome (ACS) is the leading cause of morbidity and mortality worldwide. The different reperfusion strategies have evolved over the years, and efforts have been directed to reduce its complications. Among these strategies, the one that has shown the best results is percutaneous coronary intervention, which has significantly improved the survival and prognosis of these patients; however, this procedure is not free of complications since multiple factors are involved. Among them is the time of patient care from the time of diagnosis until the coronary reperfusion therapy is performed. Methodology In this study, we describe the experience in our center with the 6-French Ikari Left guide catheter as a strategy of radial angiography-angioplasty with a single catheter to reduce the care times of patients with acute ST-elevation myocardial infarction (STEMI) in our center and compare it with the series reported by other international centers since. To establish an alternative to the usual approach that consists of the use of Judkins catheters, diagnosis, and guiding. Results Our study showed a success rate for diagnostic angiography and percutaneous coronary intervention (PCI) with the 6- French Ikari Left catheter comparable to those obtained in other centers, even with lower complication rates than the usual approach with Judkins' Catheters. Conclusions The use of the 6-French Ikari Left catheter demonstrated shorter needle-device time and compared to other international series, it was shown to be shorter and related to shorter fluoroscopy time. Our study has a small sample and only included a highly selected population, which represents a limitation. This study is vulnerable to the different practices of the operators, with involvement in procedure time and use of contrast volume.

8.
Cureus ; 15(5): e38428, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37273398

RESUMEN

Background The T-wave alterations are suggestive of ischemia, among them there is the pseudo-normalization (positivization of the T-wave, previously negative, during stress exercise). Myocardial single photon emission computed tomography (SPECT) at rest and stress is usually performed with Technetium 99 (Tc-99), which has high sensitivity and specificity for the detection of ischemic heart disease. In this study, we decided to investigate the patients who pseudo-normalized the T-wave in the stress test to correlate with the existence of ischemia diagnosed by myocardial perfusion study, specifically myocardial SPECT in perfusion and rest with Tc-99. Methodology T - wave pseudo-normalization patients who underwent a myocardial perfusion SPECT between January 2018 and June 2019 were included in this retrospective study. We analyzed 81 patients: 50 patients with pseudo-normalization of T-waves and 31 patients, as a control group, without pseudo-normalization. A descriptive analysis of the quantitative variables was performed using Student's t-test or Mann-Whitney U test, and for the qualitative variables, the χ2 test or Fisher's exact test was performed. Results The degree of ischemia according to the presence or absence of pseudo-normalization of the T-wave. The pseudo-normalization of the T-wave in the group without ischemia (48.4% vs. 36%), for the mild degree the proportions were the same (38.7% vs. 38%), the moderate degree it was slightly higher in the pseudo-normalization of the T-wave (9.7% vs. 18%) and severe (3.2% vs. 6%). Conclusions In this study, the relationship between pseudo-normalization of the T waveform and ischemia, predominantly moderate to severe, was demonstrated. However, it was not statistically significant due to the size of the sample studied.

9.
Cureus ; 15(1): e33449, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36751191

RESUMEN

Systemic lupus erythematosus (SLE) is an autoimmune disease that can affect any organ with a predisposition for women of reproductive age. It is related to a higher risk of cardiovascular events, increasing it up to 50 times in young people, and 30% of deaths are attributed to coronary artery disease. The risk of developing cardiovascular disease in SLE is related not only to traditional cardiovascular risks factors such as advanced age, hypertension, dyslipidemia, and diabetes but also to disease-specific factors, such as degree of activity, autoantibodies, organ damage, and treatment. Accelerated atherosclerosis is one of the main contributors to pathogenesis. Manifestations range from angina to acute myocardial infarction and sudden death. Markers have been studied for the detection of subclinical disease and stratification of these patients, as well as different treatment options to improve the cardiovascular prognosis of the disease.

10.
Cureus ; 15(8): e43337, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37700938

RESUMEN

Inflammatory myopathies are a group of diseases whose common pathway is immune-mediated muscle damage, one of which is polymyositis. The definition of polymyositis is controversial, with proponents advocating a definition based on immunohistochemical and histopathological findings in muscle biopsies, while other proponents advocate a definition based on clinical manifestations and histopathological findings. Polymyositis is a quite rare disease that is clinically characterized by progressive proximal muscle weakness with a symmetric distribution. Within the diagnostic approach, laboratory studies show elevation of sarcoplasmic enzymes; nerve conduction tests are performed, which may aid in distinguishing myopathic causes of weakness from neuropathic disorders; and muscle biopsy is considered the gold standard to diagnose inflammatory myopathy and to distinguish the subclasses. We report the case of a 61-year-old male patient who presented generalized symmetrical weakness, predominantly in the upper extremities, and dysphagia, whose laboratory studies, autoantibodies, and muscle biopsy were confirmatory of this entity.

11.
J Vasc Interv Radiol ; 23(2): 257-64.e4, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22178039

RESUMEN

PURPOSE: To determine local doxorubicin levels surrounding radiopaque drug-eluting beads (DEBs) in normal swine liver and kidney following transcatheter arterial chemoembolization. The influence of bead size (70-150 µm or 100-300 µm) was compared with regard to tissue penetration and spatial distribution of the bead, as well as eventual drug coverage (ie, amount of tissue exposed to drug). MATERIALS AND METHODS: Radiopaque DEBs were synthesized by suspension polymerization followed by incorporation of iodized oil and doxorubicin. Chemoembolization of swine liver and kidney was performed under fluoroscopic guidance. Three-dimensional tissue penetration of "imageable" DEBs was investigated ex vivo with micro-computed tomography (microCT). Drug penetration from the bead surface and drug coverage was evaluated with epifluorescence microscopy, and cellular localization of doxorubicin was evaluated with confocal microscopy. Necrosis was evaluated with hematoxylin and eosin staining. RESULTS: MicroCT demonstrated that 70-150-µm DEBs were present in more distal arteries and located in a more frequent and homogeneous spatial distribution. Tissue penetration of doxorubicin from the bead appeared similar (∼300 µm) for both DEBs, with a maximum tissue drug concentration at 1 hour coinciding with nuclear localization of doxorubicin. The greater spatial frequency of the 70-150-µm DEBs resulted in approximately twofold improved drug coverage in kidney. Cellular death is predominantly observed around the DEBs beginning at 8 hours, but increased at 24 and 168 hours. CONCLUSIONS: Smaller DEBs penetrated further into targeted tissue (ie, macroscopic) with a higher spatial density, resulting in greater and more uniform drug coverage (ie, microscopic) in swine.


Asunto(s)
Doxorrubicina/farmacocinética , Portadores de Fármacos/química , Embolización Terapéutica/métodos , Aceite Yodado , Riñón/diagnóstico por imagen , Riñón/metabolismo , Hígado/metabolismo , Animales , Cápsulas , Aceite Yodado/química , Hígado/diagnóstico por imagen , Tamaño de la Partícula , Radiografía , Porcinos , Distribución Tisular
12.
Eur Heart J Case Rep ; 6(8): ytac343, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36045649

RESUMEN

Background: Cardiac myxomas are the most common primary benign tumour of the heart. Most of them occur between the 4th and 6th decade of life, are most frequent in the woman, and most frequently localized in the left atrium. Case summary: We present a case of a 41-year-old female who presented with a history of left-sided heart failure. A left atrial mass of 87 × 88 × 65 mm was documented by cardiac magnetic resonance. She was taken to surgical resection of the mass. Histopathologic findings were diagnostic of cardiac myxoma. Generally, myxomas that are bigger than 6 cm are associated with the worst prognosis. Discussion: Primary cardiac tumours are mostly benign, being in 50% of the cases a cardiac myxoma. The rest of them correspond to papillary fibroelastoma (26%), fibromas (6%), lipomas (4%), and others including calcified tumours, haemangiomas, teratomas, cysts, and rhabdomyomas. Our clinical case illustrates an unusual and rare presentation of cardiac myxoma with a double mitral lesion.

13.
Disabil Rehabil Assist Technol ; 16(6): 624-631, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-31703539

RESUMEN

PURPOSE: People with Type 2 diabetes exhibit peripheral neuropathy that results in the progressive loss of sensation in their feet. This may adversely affect their ability to drive as there is the potential for their foot to slip off the accelerator or brake pedals, with unwanted consequences including traffic accidents. This research aimed to develop a prototype for an adaptive haptic foot device for diabetic drivers experiencing peripheral neuropathy that can serve as an early warning system for foot slip during driving. METHODS: A prototype system was designed in the laboratory which consisted of four force sensing resistors, four light emitting diodes and an eccentric rotating mass all connected and programmed through an Arduino Uno. The prototype was tested under controlled conditions and validated against recommended specifications. The system was then installed in a Ford Falcon GT 2005 and tested under controlled road conditions. RESULTS: The results indicated that the haptic device was effective in sensing foot locations and providing instant audio and video feedback to the driver. CONCLUSION: This research has successfully designed and fabricated a haptic feedback device that can be used as an early warning system for diabetic automobile drivers with peripheral neuropathy.IMPLICATIONS FOR REHABILITATIONA haptic foot prototype device capable of generating warning signals to diabetic drivers whose foot could slip off the brake or accelerator pedals has been developed.The prototype includes force sensing receivers integrated with eccentric rotating mass system, a haptic controller breakout board, and Arduino software.The system is very easy to use and provides highly reliable audio and visual feedback which are good alerting mechanisms for older automobile drivers.


Asunto(s)
Conducción de Automóvil , Diabetes Mellitus Tipo 2 , Enfermedades del Sistema Nervioso Periférico , Accidentes de Tránsito , Automóviles , Humanos , Tiempo de Reacción
14.
Opt Express ; 18(14): 15244-55, 2010 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-20640011

RESUMEN

A number of interrelated factors can affect the precision and accuracy of lung nodule size estimation. To quantify the effect of these factors, we have been conducting phantom CT studies using an anthropomorphic thoracic phantom containing a vasculature insert to which synthetic nodules were inserted or attached. Ten repeat scans were acquired on different multi-detector scanners, using several sets of acquisition and reconstruction protocols and various nodule characteristics (size, shape, density, location). This study design enables both bias and variance analysis for the nodule size estimation task. The resulting database is in the process of becoming publicly available as a resource to facilitate the assessment of lung nodule size estimation methodologies and to enable comparisons between different methods regarding measurement error. This resource complements public databases of clinical data and will contribute towards the development of procedures that will maximize the utility of CT imaging for lung cancer screening and tumor therapy evaluation.


Asunto(s)
Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Fantasmas de Imagen , Radiografía Torácica/métodos , Nódulo Pulmonar Solitario/diagnóstico por imagen , Nódulo Pulmonar Solitario/patología , Tomografía Computarizada por Rayos X/métodos , Humanos
15.
J Vasc Interv Radiol ; 21(6): 865-76, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20494290

RESUMEN

PURPOSE: To develop and characterize radiopaque embolization microspheres capable of in vivo detection with intraprocedural fluoroscopy and computed tomography (CT) imaging and to evaluate their spatial distribution inside target tissues during and after transcatheter embolization. MATERIALS AND METHODS: Polyvinyl alcohol hydrogel microspheres were loaded with Lipiodol and examined for iodine content, stability of loading, and conspicuity with fluoroscopy and CT in vitro. Transcatheter embolization of swine liver and kidney was performed with the radiopaque microspheres and spatial distribution was evaluated with intraprocedural fluoroscopy and CT. Ex vivo evaluation was performed with light microscopy and micro-CT. RESULTS: In vitro analyses demonstrated that radiopaque microspheres could be loaded with sufficient iodine content to be detected with routine fluoroscopy and CT imaging and that such loading was relatively stable. Radiopaque microspheres were visible in vivo with fluoroscopy and CT during transcatheter embolization. CT imaging during embolization procedures demonstrated a dose-dependent relationship in the number and size of visualized embolized arteries. Imaging features of radiopaque microsphere distribution inside target tissues correlated well with ex vivo light microscopic and micro-CT evaluation of microsphere distribution. CONCLUSIONS: Radiopaque embolization microspheres are visualized during transcatheter embolization with routine intraprocedural fluoroscopy and CT. These radiopaque microspheres provided the three-dimensional spatial distribution of embolic material inside target organs during the procedure, and therefore can provide real-time intraprocedural feedback for the interventional radiologist. These microspheres may be useful for demonstrating the influence of material and technical variability in transcatheter embolization in addition to providing intraprocedural identification of tissue at risk of undertreatment.


Asunto(s)
Cateterismo/métodos , Medios de Contraste , Embolización Terapéutica/métodos , Aceite Yodado , Microesferas , Intensificación de Imagen Radiográfica/métodos , Radiografía Intervencional/métodos , Animales , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Porcinos
16.
Cir Cir ; 75(6): 449-52, 2007.
Artículo en Español | MEDLINE | ID: mdl-18177566

RESUMEN

BACKGROUND: Restorative proctocolectomy with ileal pouch-anal anastomosis has become the most common treatment in patients with ulcerative colitis. This procedure removes the entire colon, conserving the sphincteric complex and, therefore, preserving continence. The most important goal of this surgery is to improve quality of life. METHODS: We reviewed the files of patients who underwent restorative proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis from January 1995 to December 2004 . We administered questionnaire SF-36 to evaluate quality of life. We used an observational, retrospective, and transversal method. RESULTS: Twenty "J" pouch procedures were done, of which files of 14 patients were reviewed. As far as quality of life, we were able to interview only eight patients and the average was as follows: physical function 75, physical status 50, corporal pain 51, general health 77, vitality 47.5, social function 62.50, emotional status 83 and mental health 74. DISCUSSION: Previous reports exist showing that proctocolectomy is a safe and effective procedure for patients with ulcerative colitis and where ileostomy is accompanied by one definitive, independent continent or pouch. CONCLUSIONS: The presence of stoma and fecal incontinence are factors that contribute to deterioration of quality of life after proctocolectomy; thus, both should be avoided. Of the patients who we interviewed, 87.5% consider that their health status has improved during 1 year.


Asunto(s)
Colitis Ulcerosa/cirugía , Proctocolectomía Restauradora , Calidad de Vida , Adulto , Canal Anal/cirugía , Estudios Transversales , Femenino , Humanos , Íleon/cirugía , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
17.
Nanotechnology ; 17(14): 3347-58, 2006 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-19661575

RESUMEN

Ordered surfactantless self-assembled, mesoporous SnO(2) adsorbents, consisting of tubular voids of nanometric sizes, are prepared by the sol-gel processing of tin (IV) tetra-tert-amyloxide, Sn(OAm(t))(4), whose molecules have been previously chelated with acetylacetone in the absence of water, to modulate their reactivity and to promote an incipient self-assembling of -O-Sn-O oligomeric species; ultimately, the necessary amount of water to induce the hydrolysis-condensation reactions is added to this aged sol, then producing tubular pore templates within the SnO(2) xerogel network. A collection of mesoporous SnO(2) xerogels of assorted structural properties has been obtained after calcination in air of precursory gels proceeding from an aged mixture of Sn(OAm(t))(4) and acetylacetone at temperatures in the range 200-1000 degrees C. N(2) sorption isotherms measured on these SnO(2) solids evidence mesoporous structures of diverse textural characteristics (i.e. pore widths of 3-50 nm and surface areas of 10-140 m(2) g(-1)) in which voids virtually behave as if they are independent cylindrical pores during capillary condensation and evaporation.

18.
Rev Gastroenterol Mex ; 71(4): 428-32, 2006.
Artículo en Español | MEDLINE | ID: mdl-17542274

RESUMEN

BACKGROUND DATA: Haemorrhoids and the symptoms they produce have been recorded throughout history. This disease affects 4-10% of the population. The treatment is based on the degree of haemorrhoidal prolapse and the severity of symptoms. OBJECTIVES: The aim of this study is to show our experience in the treatment of haemorrhoidal disease in the colorectal surgery department from the Centro Médico Nacional Siglo XXI, (IMSS, México, D.F). METHODS: Clinical files were reviewed of patients treated by surgical procedures in a period from March 1996 to March 2004. RESULTS: 3,304 medical consultations were given to first time patients; 443 patients were diagnosed with haemorrhoidal disease representing 13.4% of the anorectal pathology: 358 patients underwent an anorectal operation, 225 males (62.8%) and 133females (37.2%), mean age of 48 years (range 18-78 years). The principal symptoms were bleeding and pain. We found another associated pathology in 20% of the cases. 46 patients were affected by second degree haemorrhoids (12.8%), 244 third degree (68.3%) and 68 patients by fourth degree (19%). The Ferguson technique was the most used (84%). At the same time as the haemorrhoidectomy we did other anorrectal procedures in 20% of patients. The mean operation time was 53 minutes (range 19-150). Acute urinary retention occurred in 28 patients (8%) leak sutures in seven (2%), and bleeding in six (1.7%). The mean hospital stays were two days with follow up of 42 days. The total morbility was 4.7%. CONCLUSIONS: The incidence of haemorrhoidal disease in this study was 13.4%. 80% ofpatients were treated by surgery. This pathology is more common in the fifth decade of life with male-female relation of 1. 7:1. The acute urinary retention was the most common complication. During the performing of a haemorrhoidectomy it was possible to resolve other anorectal pathologies. The Ferguson technique was the most used with a total morbility of 4.7%.


Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo , Hemorroides/epidemiología , Hemorroides/cirugía , Adolescente , Adulto , Factores de Edad , Anciano , Femenino , Hemorroides/complicaciones , Humanos , Masculino , México/epidemiología , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Suturas , Resultado del Tratamiento , Retención Urinaria/etiología
19.
Acta sci., Biol. sci ; Acta sci., Biol. sci;42: e49958, fev. 2020. map, tab, ilus, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1460952

RESUMEN

Less than 10% of the original Atlantic Forest cover now remains standing in the Brazilian state of Sergipe, although few scientific studies have focused on its mammalian diversity. The present study describes the diversity of non-volant mammals found in the Ibura National Forest (INF), based on live trapping, and direct and indirect observations. We sampled the IBF on six days per month between June 2012 and August 2013, using live-traps (Sherman-type) positioned in pairs (ground and understory). We equally sampled semideciduous forest and an abandoned Eucalyptusplantation with dense understory (over 30 years). We also used non-systematics methods (direct observations, vestiges, camera-trap, and opportunistic captures). We recorded 18 species, from 12 families and 7 orders considering all the applied methods. Among recorded species, Bradypus torquatusand Lontra longicaudisare considered threatened of extinction. Considering only the live-trapping (totaling 3,240 trapping nights), we captured 125 individuals (3.85% success) from four species, Marmosa demerarae(52%), Didelphis albiventris(19.2%), Cerradomys vivoi(15.2%), and M. murina(13.6%). Estimated and observed richness was the same, suggesting a satisfactory effort. Didelphis albiventrisand M. demeraraeshowed significantly higher captures in the dry seasons. Didelphis albiventrisand C.vivoishowed significantly higher captures in the substratum, and M. demeraraehigher in the understory. Cerradomysvivoishowed significantly higher captures in the Eucalyptusphytophysiognomy. Non-Metric Multidimensional Scaling and the ANOSIM showed a significant difference in the captured species among semidecidual forest and Eucalyptus. Despite the small area (144 ha), the INF still houses a relatively high mammalian diversity. Further investigations may help to understand the role of habitat reduction in the diversity and habitat partitioning among mammal species in the Atlantic Forest of Northeastern Brazil.


Asunto(s)
Animales , Biodiversidad , Ecosistema , Mamíferos/anatomía & histología , Áreas Protegidas/análisis
20.
Rev Gastroenterol Mex ; 67(1): 28-33, 2002.
Artículo en Español | MEDLINE | ID: mdl-12066428

RESUMEN

UNLABELLED: Primary colon lymphomas (PCL) are very rare tumors of the gastrointestinal tract, and represent 0.2-0.5% of all colon primary tumors. They appear principally PCL in adult population. Almost all are non-Hodgkin's lymphomas; first however, one must discard lymph node origin. The most frequent sites of presentation are the cecum and rectum. Treatment of choice is surgical, plus adjuvant chemotherapy. Radiotherapy is reserved for specific cases. OBJECTIVE: To inform on two cases of PCL. METHOD: Review two of cases of cecum lymphomas and their treatment. RESULTS: We inform the cases of two patients with the diagnosis of cecum lymphoma. The main patient complaints were abdominal pain, palpable mass, and hemorrhage. Both patients were treated with right extended hemicolectomy and ileum-transverse anastomosis. The outcome was unremarkable. Both patients received chemotherapy and remain free of disease at 1.5 and 5 years of follow-up. CONCLUSIONS: Primary colon lymphomas are very uncommon gastrointestinal tumors, with cecum localization as one of the most frequent sites of presentation in the colon. Treatment of choice must be surgical, with chemotherapy as an adjuvant therapy to improve survival.


Asunto(s)
Neoplasias del Colon/terapia , Linfoma/terapia , Adulto , Anciano , Femenino , Humanos , Masculino
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