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1.
Clin Radiol ; 79(10): e1268-e1278, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39084932

RESUMEN

AIMS: Iliocaval venous tumor thrombus is a morbid condition associated with chronic venous stasis, lower extremity edema/pain, extensive thrombus burden and high mortality secondary to critical flow obstruction, intracardiac thrombus extension and tumor embolization. Typically resistant to medical therapy, management is primarily surgical, presenting challenges for medically complex patients with widespread or end-stage disease. Mechanical or aspiration thrombectomy represents an appealing treatment strategy but data are lacking. MATERIALS AND METHODS: We performed a single-center, 10-year, retrospective review of patients with pathology-confirmed, iliocaval tumor thrombus who underwent thrombectomy. 14 patients met inclusion criteria and were managed by 18 procedures over this period. RESULTS: The most common malignancy was renal-cell carcinoma (n=7; 50%); other types included germ cell (n=2; 14%), other genitourinary (n=2; 14%), neuroendocrine (n=1; 7%), soft tissue (n=1; 7%), and skin cell malignancies (n=1; 7%). All patients had thrombus involving the distal inferior venous cava (IVC), 50% had bilateral iliac involvement and 29% atrial involvement. Common indications were venous obstruction symptoms (n=11; 65%) and evidence of embolism (n=6; 35%). All patients tolerated the procedures without acute complication. The technical success rate was 94%, with marked improvement of flow and reduction in thrombus burden, and 79% had subjective symptomatic improvement. All patients survived for >2 weeks and 50% had long-term survival of >1 year, with 86% of these patients having renal-cell carcinoma (RCC). Three patients underwent multiple thrombectomies within days to weeks, with ultimate symptomatic improvement. CONCLUSIONS: Overall, our study results suggest mechanical or aspiration thrombectomy as a safe and efficacious treatment for patients with iliocaval tumor thrombus.


Asunto(s)
Procedimientos Endovasculares , Trombectomía , Vena Cava Inferior , Trombosis de la Vena , Humanos , Trombectomía/métodos , Masculino , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Adulto , Trombosis de la Vena/diagnóstico por imagen , Trombosis de la Vena/cirugía , Vena Cava Inferior/diagnóstico por imagen , Vena Cava Inferior/cirugía , Anciano , Procedimientos Endovasculares/métodos , Resultado del Tratamiento , Vena Ilíaca/diagnóstico por imagen , Vena Ilíaca/cirugía , Células Neoplásicas Circulantes , Adulto Joven
2.
Clin Radiol ; 78(2): e143-e149, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36344283

RESUMEN

AIM: To determine the costs associated with endovascular pulmonary embolism (PE) interventions. MATERIALS AND METHODS: Procedural costs were determined utilising time-driven activity-based costing (TDABC). A multidisciplinary team created process maps describing personnel, space, equipment, materials, and time required for each procedural step. Costs and capacity cost rates were determined using institutional and publicly available financial data. RESULTS: Process maps were developed for catheter-directed thrombolysis (CDT), ultrasound-assisted thrombolysis (USAT), pharmaco-mechanical thrombectomy (PMT), mechanical-aspiration thrombectomy (MAT), and aspiration thrombectomy (AT). Total costs were CDT $3,889, USAT $9,017.10, PMT $9,565.98, AT $12,126.42, and MAT $13,748.01. Tissue plasminogen activator costs represented 46.4% of the total materials cost for CDT, 13.1% for PMT, and 10.8% for USAT. Intensive care unit costs constitute 33.4% in CDT, 13.5% in USAT, and 13.1% in PMT of the total procedure costs. Highest total procedural costs were AT and MAT with materials cost comprising 82.6% and 80.3% of total costs, respectively. CONCLUSION: Costs were greatest with large-bore mechanical aspiration and least with catheter-directed thrombolysis using a multi-side hole infusion catheter. In the absence of a reference standard technique, physician-driven device selection can substantially impact the price of a procedure. Device choice and costs must be weighed against long-term technical and clinical success to maximise the healthcare value equation.


Asunto(s)
Embolia Pulmonar , Activador de Tejido Plasminógeno , Humanos , Activador de Tejido Plasminógeno/uso terapéutico , Fibrinolíticos/uso terapéutico , Terapia Trombolítica/métodos , Resultado del Tratamiento , Embolia Pulmonar/diagnóstico por imagen , Embolia Pulmonar/cirugía , Trombectomía/métodos , Estudios Retrospectivos
3.
Philos Trans A Math Phys Eng Sci ; 379(2202): 20190438, 2021 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-34092105

RESUMEN

This paper investigates large fluctuations of locational marginal prices (LMPs) in wholesale energy markets caused by volatile renewable generation profiles. Specifically, we study events of the form [Formula: see text] where LMP is the vector of LMPs at the n power grid nodes, and α-, [Formula: see text] are vectors of price thresholds specifying undesirable price occurrences. By exploiting the structure of the supply-demand matching mechanism in power grids, we look at LMPs as deterministic piecewise affine, possibly discontinuous functions of the stochastic input process, modelling uncontrollable renewable generation. We use techniques from large deviations theory to identify the most likely ways for extreme price spikes to happen, and to rank the nodes of the power grid in terms of their likelihood of experiencing a price spike. Our results are derived in the case of Gaussian fluctuations, and are validated numerically on the IEEE 14-bus test case. This article is part of the theme issue 'The mathematics of energy systems'.

4.
Ann Vasc Surg ; 77: 353.e1-353.e5, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34461237

RESUMEN

Percutaneous mitral valve (MV) repair using MitraClip requires large-caliber venous access. We describe a patient with a ligated inferior vena cava due to an Adams-DeWeese clip placed 50 years prior, who had progressive shortness of breath and lower extremity symptoms secondary to severe mitral regurgitation and chronic iliocaval deep venous thrombosis. Due to comorbidities, MitraClip was recommended over surgery for MV repair. Caval luminal gain was required to facilitate endovascular access for the MitraClip system. Stent-mediated release of the inferior vena cava clip allowed successful passage of the delivery sheath from the common femoral vein to MV and subsequent valve repair.


Asunto(s)
Angioplastia de Balón , Cateterismo Cardíaco/instrumentación , Implantación de Prótesis de Válvulas Cardíacas/instrumentación , Prótesis Valvulares Cardíacas , Insuficiencia de la Válvula Mitral/cirugía , Válvula Mitral/cirugía , Instrumentos Quirúrgicos , Procedimientos Quirúrgicos Vasculares/instrumentación , Vena Cava Inferior/cirugía , Anciano de 80 o más Años , Angioplastia de Balón/instrumentación , Humanos , Masculino , Válvula Mitral/diagnóstico por imagen , Válvula Mitral/fisiopatología , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/fisiopatología , Recuperación de la Función , Índice de Severidad de la Enfermedad , Stents , Resultado del Tratamiento , Vena Cava Inferior/fisiopatología
5.
Philos Trans A Math Phys Eng Sci ; 375(2100)2017 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-29052544

RESUMEN

The real-time detection of changes in a noisily observed signal is an important problem in applied science and engineering. The study of parametric optimal detection theory began in the 1930s, motivated by applications in production and defence. Today this theory, which aims to minimize a given measure of detection delay under accuracy constraints, finds applications in domains including radar, sonar, seismic activity, global positioning, psychological testing, quality control, communications and power systems engineering. This paper reviews developments in optimal detection theory and sequential analysis, including sequential hypothesis testing and change-point detection, in both Bayesian and classical (non-Bayesian) settings. For clarity of exposition, we work in discrete time and provide a brief discussion of the continuous time setting, including recent developments using stochastic calculus. Different measures of detection delay are presented, together with the corresponding optimal solutions. We emphasize the important role of the signal-to-noise ratio and discuss both the underlying assumptions and some typical applications for each formulation.This article is part of the themed issue 'Energy management: flexibility, risk and optimization'.

6.
Parasitology ; 143(14): 1847-1861, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27608857

RESUMEN

Notoedric mange, caused by obligately parasitic sarcoptiform Notoedres mites, is associated with potentially fatal dermatitis with secondary systemic disease in small mammals, felids and procyonids among others, as well as an occasional zoonosis. We describe clinical spectra in non-chiropteran hosts, review risk factors and summarize ecological and epidemiological studies. The genus is disproportionately represented on rodents. Disease in felids and procyonids ranges from very mild to death. Knowledge of the geographical distribution of the mites is highly inadequate, with focal hot spots known for Notoedres cati in domestic cats and bobcats. Predisposing genetic and immunological factors are not known, except that co-infection with other parasites and anticoagulant rodenticide toxicoses may contribute to severe disease. Treatment of individual animals is typically successful with macrocytic lactones such as selamectin, but herd or wildlife population treatment has not been undertaken. Transmission requires close contact and typically is within a host species. Notoedric mange can kill half all individuals in a population and regulate host population below non-diseased density for decades, consistent with frequency-dependent transmission or spillover from other hosts. Epidemics are increasingly identified in various hosts, suggesting global change in suitable environmental conditions or increased reporting bias.


Asunto(s)
Enfermedades de los Gatos/parasitología , Infestaciones por Ácaros/veterinaria , Ácaros/fisiología , Animales , Animales Salvajes/parasitología , Gatos/parasitología , Coinfección/parasitología , Coinfección/veterinaria , Estadios del Ciclo de Vida , Lynx/parasitología , Infestaciones por Ácaros/tratamiento farmacológico , Infestaciones por Ácaros/epidemiología , Infestaciones por Ácaros/parasitología , Ácaros/clasificación , Ácaros/crecimiento & desarrollo , Mascotas/parasitología , Enfermedades de los Roedores/parasitología , Roedores , Piel/parasitología , Urbanización
7.
Br J Anaesth ; 116(2): 177-91, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26787788

RESUMEN

BACKGROUND: Cardiopulmonary exercise testing (CPET) is used as a preoperative risk-stratification tool for patients undergoing non-cardiopulmonary intra-abdominal surgery. Previous studies indicate that CPET may be beneficial, but research is needed to quantify CPET values protective against poor postoperative outcome [mortality, morbidity, and length of stay (LOS)]. METHODS: This systematic review aimed to assess the ability of CPET to predict postoperative outcome. The following databases were searched: PubMed, EMBASE, PEDro, The Cochrane Library, Cinahl, and AMED. Thirty-seven full-text articles were included. Data extraction included the following: author, patient characteristics, setting, surgery type, postoperative outcome measure, and CPET outcomes. RESULTS: Surgeries reviewed were hepatic transplant and resection (n=7), abdominal aortic aneurysm (AAA) repair (n=5), colorectal (n=6), pancreatic (n=4), renal transplant (n=2), upper gastrointestinal (n=4), bariatric (n=2), and general intra-abdominal surgery (n=12). Cardiopulmonary exercise testing-derived cut-points, peak oxygen consumption ([Formula: see text]), and anaerobic threshold (AT) predicted the following postoperative outcomes: 90 day-3 yr survival (AT 9-11 ml kg(-1) min(-1)) and intensive care unit admission (AT <9.9-11 ml kg(-1) min(-1)) after hepatic transplant and resection, 90 day survival after AAA repair ([Formula: see text] 15 ml kg(-1) min(-1)), LOS and morbidity after pancreatic surgery (AT <10-10.1 ml kg(-1) min(-1)), and mortality and morbidity after intra-abdominal surgery (AT 10.9 and <10.1 ml kg(-1) min(-1), respectively). CONCLUSION: Cardiopulmonary exercise testing is a useful preoperative risk-stratification tool that can predict postoperative outcome. Further research is needed to justify the ability of CPET to predict postoperative outcome in renal transplant, colorectal, upper gastrointestinal, and bariatric surgery.


Asunto(s)
Abdomen/cirugía , Prueba de Esfuerzo/estadística & datos numéricos , Complicaciones Posoperatorias/diagnóstico , Cuidados Preoperatorios/estadística & datos numéricos , Humanos , Estimación de Kaplan-Meier , Tiempo de Internación/estadística & datos numéricos , Consumo de Oxígeno , Curva ROC , Medición de Riesgo
8.
Ecotoxicology ; 24(4): 844-62, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25707484

RESUMEN

Anticoagulant rodenticides (ARs) are increasingly recognized as a threat to nontarget wildlife. High exposure to ARs has been documented globally in nontarget predatory species and linked to the high prevalence of an ectoparasitic disease, notoedric mange. In southern California, mange associated with AR exposure has been the proximate cause of a bobcat (Lynx rufus) population decline. We measured AR exposure in bobcats from two areas in southern California, examining seasonal, demographic and spatial risk factors across landscapes including natural and urbanized areas. The long-term study included bobcats sampled over a 16-year period (1997-2012) and a wide geographic area. We sampled blood (N = 206) and liver (N = 172) to examine exposure ante- and post-mortem. We detected high exposure prevalence (89 %, liver; 39 %, blood) and for individuals with paired liver and blood data (N = 64), 92 % were exposed. Moreover, the animals with the most complete sampling were exposed most frequently to three or more compounds. Toxicant exposure was associated with commercial, residential, and agricultural development. Bobcats of both sexes and age classes were found to be at high risk of exposure, and we documented fetal transfer of multiple ARs. We found a strong association between certain levels of exposure (ppm), and between multiple AR exposure events, and notoedric mange. AR exposure was prevalent throughout both regions sampled and throughout the 16-year time period in the long-term study. ARs pose a substantial threat to bobcats, and likely other mammalian and avian predators, living at the urban-wildland interface.


Asunto(s)
Anticoagulantes/toxicidad , Exposición a Riesgos Ambientales , Lynx/metabolismo , Rodenticidas/toxicidad , Animales , California , Femenino , Hígado/efectos de los fármacos , Masculino , Infestaciones por Ácaros/inducido químicamente , Factores de Riesgo , Estaciones del Año , Población Urbana
9.
Ir Med J ; 106(3): 82-4, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23951978

RESUMEN

We report the results of a survey of Irish anaesthetic specialist trainees to establish their future training intentions, their interest in seeking a Consultant position in Ireland and identification of factors that may reduce the attractiveness of future employment in the HSE. 149 responses were received (71% of trainees). 137 (92%) are likely to complete further training abroad, but only 24 (16.1%) are definitely planning to return to work in Ireland. Factors, in order of importance that influence their return to Ireland include equivalence of all Consultants, salary level and availability of flexible work practices. Almost all (131 - 91%) would only consider working in Ireland at Consultant level. These results reveal that the current cohort of specialist trainees do not consider Ireland an attractive place to work, and any further diminution of the current Consultant grade will only serve to worsen this perception.


Asunto(s)
Anestesiología , Actitud , Consultores/psicología , Educación de Postgrado en Medicina , Internet , Salarios y Beneficios , Tolerancia al Trabajo Programado/psicología , Adulto , Encuestas Epidemiológicas , Humanos , Intención , Irlanda , Encuestas y Cuestionarios
10.
Gynecol Oncol Rep ; 36: 100782, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34036138

RESUMEN

Placental Site Trophoblastic Tumor (PSTT) is a rare malignancy that often presents with extensive disease and can be resistant to traditional treatments. We present the case of a woman with stage IV PSTT who was initially managed with neoadjuvant chemotherapy followed by tumor debulking. Adjuvant therapy was guided by further pathologic analysis that revealed high levels of staining for PD-L1 as well as the presence of tumor infiltrating lymphocytes (TILs). Subsequently, the patient was treated with traditional chemotherapy with the EP/EMA regimen with the addition of pembrolizumab. The patient's treatment course was complicated by the development of pulmonary arteriovenous malformations, autoimmune thyroiditis thought to be secondary to immunotherapy, and significant tinnitus secondary to platinum agents. Currently the patient is in follow up and remains in a complete remission.

11.
Phys Rev Lett ; 104(25): 255702, 2010 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-20867396

RESUMEN

Phase diagrams of refractory metals remain essentially unknown. Moreover, there is an ongoing controversy over the high-pressure melting temperatures of these metals: results of diamond anvil cell (DAC) and shock wave experiments differ by at least a factor of 2. From an extensive ab initio study on tantalum we discovered that the body-centered cubic phase, its physical phase at ambient conditions, transforms to another solid phase, possibly hexagonal omega phase, at high temperature. Hence the sample motion observed in DAC experiments is very likely not due to melting but internal stresses accompanying a solid-solid transformation, and thermal stresses associated with laser heating.

12.
Science ; 155(3762): 553-6, 1967 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-17737404

RESUMEN

Excavations at site U.C.L.J.-M-15 at Agua Hedionda Lagoon in southern California have provided a radiocarbon date of 7070 B.C. for a transitional phase between the San Dieguito and the La Jolla complex. The many radiocarbon dates taken from sites in San Diego County demonstrate a somewhat greater age than was hitherto generally expected for the three cultures in the area. The age of the most recent culture, the Yuman-Diegueno, has been extended to about 1000 B.C. The La Jolla shows an extremely long period of occupation spanning roughly 1000 B.C. to 7070 B.C. The third group, the San Dieguito, a pre-Desert culture, is still undated. Samples are now in process and should, judged from the new La Jolla dates, give a date earlier than 7000 B.C. for the earliest phases of the San Dieguito.

13.
Cardiovasc Intervent Radiol ; 42(3): 460-465, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30603971

RESUMEN

PURPOSE: To report technical success and clinical outcomes of transfemoral venous access for upper extremity dialysis interventions. MATERIALS AND METHODS: A total of 15 patients underwent a transfemoral venous approach for fistulography (n = 4; 27%) or thrombectomy (n = 11; 73%) over a 14-month period. Access characteristics, sheath size, thrombectomy method, angioplasty site, fluoroscopy time, radiation dose, technical and clinical success, complications, and post-intervention primary and secondary patency rates were recorded. RESULTS: Access type included arteriovenous fistulas (n = 10; 67%) and grafts (n = 5; 33%). The most common configuration was brachio-brachial (n = 6; 38%). Mean age of access was 37 months. Mean prior interventions were 4. Right CFV access was used in all patients using 6-8-French (most common: 7-French [n = 10; 67%]) sheaths. Most thrombectomies (n = 11; 73%) required both pharmacologic and mechanical maceration (n = 9; 82%). All accesses required angioplasty to treat underlying stenosis at the outflow vein (n = 12; 80%) or arteriovenous anastomosis (n = 9; 90%). Mean fluoroscopy time was 26.43 min. Air kerma and dose area product were 178.06 ± 225.77 mGy and 57,768.83 ± 87,553.29 µGym2, respectively. Procedural and clinical success rates were 93% and 80%, respectively. Technical failure was due to persistent stenosis in one patient. Clinical failure was due to unsuccessful dialysis immediately following intervention in three patients. Mean post-intervention primary patency and secondary patency durations were 2.8 and 4.8 months, respectively. Primary patency rates at 1 and 3 months were 50% and 35%, respectively. Secondary patency rates at 1 and 3 months were 58% and 30%, respectively. CONCLUSION: A transfemoral venous approach for intervention of upper extremity dialysis accesses may be a valuable adjunct to traditional approaches.


Asunto(s)
Derivación Arteriovenosa Quirúrgica/métodos , Procedimientos Endovasculares/métodos , Vena Femoral , Diálisis Renal/métodos , Extremidad Superior/irrigación sanguínea , Grado de Desobstrucción Vascular/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Fluoroscopía , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
14.
Vet Rec ; 162(13): 409-12, 2008 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-18375985

RESUMEN

This is the first report of a major outbreak of a paralytic disease in cattle on a farm in the Republic of Ireland. Thirty-six of 65 dairy cows were euthanased or died. A presumptive diagnosis of botulism was made on the basis of the clinical signs, the duration of the outbreak and the postmortem findings, and by ruling out other differential diagnoses.


Asunto(s)
Botulismo/veterinaria , Enfermedades de los Bovinos/epidemiología , Brotes de Enfermedades/veterinaria , Alimentación Animal/efectos adversos , Animales , Botulismo/diagnóstico , Botulismo/epidemiología , Botulismo/mortalidad , Bovinos , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/mortalidad , Industria Lechera , Diagnóstico Diferencial , Femenino , Irlanda/epidemiología
15.
Cardiovasc Intervent Radiol ; 41(12): 1826-1839, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30039506

RESUMEN

Chronic thromboembolic pulmonary hypertension (CTEPH) is a potentially lethal outcome of pulmonary embolism. Balloon pulmonary angioplasty (BPA) is aimed at improving pulmonary perfusion and pulmonary hemodynamics and has gained a lot of interest recently in patients either unsuitable for or refractory to surgical pulmonary endarterectomy. This article outlines the clinical features and diagnostic criteria, imaging evaluation, current medical and surgical treatment options for CTEPH. BPA is discussed in detail, focusing on the rationale, patient selection, technical details, post-procedural care and outcomes.


Asunto(s)
Angioplastia de Balón/métodos , Hipertensión Pulmonar/terapia , Embolia Pulmonar/terapia , Enfermedad Crónica , Hemodinámica , Humanos , Hipertensión Pulmonar/etiología , Selección de Paciente , Arteria Pulmonar , Embolia Pulmonar/complicaciones
16.
Vet Parasitol ; 146(3-4): 227-34, 2007 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-17368946

RESUMEN

Thoracic fluid (pleural fluid and clotted blood) from 206 foxes were examined for antibodies to Toxoplasma gondii and 220 thoracic fluid samples were tested for Neospora caninum antibodies using indirect immunofluorescent antibody tests (IFAT). A total of 115 (56%) and six (3%) foxes had antibodies to T. gondii and N. caninum, respectively. The brains from 148 foxes were examined for histological lesions and pathological changes suggestive of parasitic encephalitis were observed in 33 (22%). Two thirds of these foxes had antibodies to T. gondii and one fox had antibodies to both T. gondii and N. caninum. PCR assays carried out on DNA extracted from the 33 brains with histological lesions were negative for N. caninum but one of the brains was positive for T. gondii. Microsporidian DNA was also amplified from the brains of two of these foxes. Sequencing these amplicons revealed 100% homology with Encephalitozoon (Septata) intestinalis in one fox and Encephalitozoon cuniculi in the second fox. This is the first report of Encephalitozoon infections in wildlife in Ireland.


Asunto(s)
Encephalitozoon/aislamiento & purificación , Zorros/parasitología , Neospora/aislamiento & purificación , Toxoplasma/aislamiento & purificación , Animales , Coccidiosis/epidemiología , Coccidiosis/veterinaria , Encefalitozoonosis/epidemiología , Encefalitozoonosis/veterinaria , Irlanda/epidemiología , Toxoplasmosis Animal/epidemiología
17.
Cancer Res ; 50(17): 5250-6, 1990 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-2386935

RESUMEN

The MAT-B1 and MAT-C1 ascites sublines of the 13762 rat mammary adenocarcinoma contain a dominant cell surface "complex" consisting of two glycoproteins: ascites sialoglycoprotein (ASGP)-1, a Mr 600,000-700,000 peanut agglutinin-binding sialomucin, and ASGP-2, a Mr 120,000 concancavalin A-binding glycoprotein (Sherblom et al., J. Biol. Chem., 255: 783-790, 1980; Sherblom and Carraway, J. Biol. Chem., 255: 12051-12059, 1980). Although both cell lines are resistant to lysis by natural killer cells, treatments which result in loss of cell surface ASGP-1 render the cells susceptible to natural killer cell lysis (Sherblom and Moody, Cancer Res., 46:4543-4546, 1986). Treatment of the ascites cells with 5 micrograms/ml tunicamycin for 24 h effectively inhibits glycosylation of ASGP-2 without affecting cell viability or total protein synthesis. Under these conditions, expression of ASGP-1 is depressed by at least 50% in both cell lines, as monitored by [3H]glucosamine incorporation and by binding of peanut agglutinin to intact cells. The size distribution of O-linked oligosaccharides in ASGP-1 from tunicamycin-treated versus control MAT-B1 cells is indistinguishable, as determined by Bio-Gel P-4 chromatography following alkaline-borohydride treatment. Complex isolated from either treated or control cells bands at the same density in a CsCl gradient containing Triton X-100 and contains a diffuse band corresponding to ASGP-2 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Tunicamycin-treated cells, consistent with the reduced expression of ASGP-1, are significantly more susceptible to natural killer cell-mediated lysis, when compared to untreated controls. The results suggest that N-linked glycosylation is a prerequisite for sialomucin synthesis and/or complex formation.


Asunto(s)
Adenocarcinoma/fisiopatología , Células Asesinas Naturales/inmunología , Neoplasias Mamarias Experimentales/fisiopatología , Proteínas de Neoplasias/metabolismo , Sialoglicoproteínas/metabolismo , Tunicamicina/farmacología , Adenocarcinoma/inmunología , Animales , Citotoxicidad Inmunológica , Femenino , Glucosamina/metabolismo , Lectinas , Leucina/metabolismo , Neoplasias Mamarias Experimentales/inmunología , Glicoproteínas de Membrana/aislamiento & purificación , Glicoproteínas de Membrana/metabolismo , Peso Molecular , Mucina 4 , Ratas , Ratas Endogámicas F344 , Sialoglicoproteínas/aislamiento & purificación , Células Tumorales Cultivadas/inmunología , Células Tumorales Cultivadas/fisiología
18.
Cancer Res ; 50(21): 6800-5, 1990 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-2208144

RESUMEN

The potential role of cell surface sialomucin in preventing natural killer (NK)-mediated lysis of tumor cell targets has been addressed by comparing the properties of 2 NK-resistant [ascites (ASC) and short-term cultured (STC)] and 2 NK-susceptible [tunicamycin-treated (TUN) and long-term cultured (LTC)] preparations of 13762 MAT-B1 rat mammary tumor cells. Both the ASC and STC cell preparations contain elevated levels of the sialomucin ASGP-1 relative to TUN and LTC preparations as determined by [3H]glucosamine labeling and by binding of peanut agglutinin. The major difference in the susceptibility to NK-mediated lysis appeared to be due to the differences in the susceptibility to lysis by lytic granules, rather than to differences in the ability to bind or trigger effector cells, since TUN and LTC cells were approximately 10-fold more sensitive to lysis by lytic granules than were ASC and STC cells. All preparations inhibited the lysis of the susceptible target YAC-1 by normal rat splenocytes, indicating an ability to bind these effector cells. Triggering of effectors, as monitored either by incorporation of 32P into phosphatidylinositol or by transmethylation of phosphatidylcholine, was similar for the positive control YAC-1, STC, TUN, and LTC, whereas ASC appeared to be defective in triggering effectors. These results suggest that tumor sialomucin blocks the final phase of lysis, but not the initial recognition of tumor cells by NK effectors.


Asunto(s)
Adenocarcinoma/metabolismo , Células Asesinas Naturales/fisiología , Neoplasias Mamarias Experimentales/metabolismo , Mucinas/metabolismo , Adenocarcinoma/patología , Animales , Ascitis/metabolismo , Ascitis/patología , Femenino , Glicoproteínas/metabolismo , Metabolismo de los Lípidos , Neoplasias Mamarias Experimentales/patología , Mucinas/fisiología , Ratas , Sialomucinas , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/farmacología , Tunicamicina/farmacología
19.
J Clin Endocrinol Metab ; 75(3): 871-8, 1992 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1381373

RESUMEN

Autoimmune thyroid disease is associated with enhanced expression of major histocompatibility complex class I antigens on thyrocytes. To better understand this phenomenon, we have studied the normal expression of class I genes in FRTL-5 rat thyroid cells. A variety of hormones and growth factors that regulate the growth and function of these thyroid cells were found to decrease class I RNA levels: serum, insulin or insulin-like growth factor-I (IGF-I), and hydrocortisone. Antibody preparations from Graves' patients (thyroid-stimulating antibodies), which increase cAMP levels and stimulate the thyroid, also decrease class I RNA levels. This is consistent with the fact that TSH, via its cAMP signal, reduces class I transcripts. The class I response to TSH, serum, insulin, IGF-I, or hydrocortisone is specific, in that the same agents do not similarly affect TSH receptor, thyroglobulin, thyroid peroxidase, malic enzyme, or beta-actin RNA levels. Both gamma- and alpha-interferon increase class I RNA levels in FRTL-5 cells, even in the presence of the serum, IGF-I, or hormones noted above, i.e. they overcome hormonal negative regulation in normal thyrocytes. In contrast, methimazole treatment of rat FRTL-5 thyroid cells, but not rat fibroblasts or rat FRT thyroid cells, which have no TSH receptor and no TSH-regulated function, results in reduced class I RNA levels. The action of methimazole can inhibit interferon action, is transcriptional, is duplicated by iodide, and is additive with the negative regulatory action of hormones and serum factors, including TSH.


Asunto(s)
Regulación de la Expresión Génica , Antígenos de Histocompatibilidad Clase I/genética , Hormonas/fisiología , Interferones/farmacología , Yoduros/farmacología , Metimazol/farmacología , Glándula Tiroides/fisiología , Animales , Anticuerpos/fisiología , Regulación de la Expresión Génica/efectos de los fármacos , Ratas , Glándula Tiroides/citología , Tirotropina/inmunología
20.
Biol Psychiatry ; 35(6): 375-80, 1994 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-8018783

RESUMEN

In order to study the nature of dopaminergic activity in epileptic psychoses we investigated striatal dopamine receptor binding in 14 patients with epilepsy. Seven of the patients were acutely psychotic when studied, having recently developed a periictal schizophreniform psychosis. The remaining patients were not psychotic. All patients were scanned using single photon emission tomography (SPET) with 123I-IBZM, a specific dopamine D2 receptor ligand. A region of interest analysis was performed. Comparison of mean basal ganglia to occipital cortex activity ratios in the two groups demonstrated significantly reduced specific binding of 123I-IBZM to striatal D2 receptors in the psychotic patients compared to those without psychosis.


Asunto(s)
Ganglios Basales/diagnóstico por imagen , Sitios de Unión , Epilepsia/complicaciones , Lóbulo Occipital/diagnóstico por imagen , Trastornos Psicóticos/complicaciones , Trastornos Psicóticos/diagnóstico por imagen , Receptores de Dopamina D2/metabolismo , Tomografía Computarizada de Emisión de Fotón Único , Adulto , Benzamidas/farmacocinética , Humanos , Masculino , Persona de Mediana Edad , Pirrolidinas/farmacocinética
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