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2.
Vaccine ; 40(46): 6631-6639, 2022 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-36210251

RESUMEN

Rotavirus vaccination has been shown to reduce rotavirus burden in many countries, but the long-term magnitude of vaccine impacts is unclear, particularly in low-income countries. We use a transmission model to estimate the long-term impact of rotavirus vaccination on deaths and disability adjusted life years (DALYs) from 2006 to 2034 for 112 low- and middle-income countries. We also explore the predicted effectiveness of a one- vs two- dose series and the relative contribution of direct vs indirect effects to overall impacts. To validate the model, we compare predicted percent reductions in severe rotavirus cases with the percent reduction in rotavirus positivity among gastroenteritis hospital admissions for 10 countries with pre- and post-vaccine introduction data. We estimate that vaccination would reduce deaths from rotavirus by 49.1 % (95 % UI: 46.6-54.3 %) by 2034 under realistic coverage scenarios, compared to a scenario without vaccination. Most of this benefit is due to direct benefit to vaccinated individuals (explaining 69-97 % of the overall impact), but indirect protection also appears to enhance impacts. We find that a one-dose schedule would only be about 57 % as effective as a two-dose schedule 12 years after vaccine introduction. Our model closely reproduced observed reductions in rotavirus positivity in the first few years after vaccine introduction in select countries. Rotavirus vaccination is likely to have a substantial impact on rotavirus gastroenteritis and its mortality burden. To sustain this benefit, the complete series of doses is needed.


Asunto(s)
Gastroenteritis , Infecciones por Rotavirus , Vacunas contra Rotavirus , Rotavirus , Humanos , Lactante , Infecciones por Rotavirus/prevención & control , Gastroenteritis/prevención & control , Vacunación , Análisis Costo-Beneficio
3.
J Phys Condens Matter ; 33(10): 104001, 2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33246318

RESUMEN

Suspensions of charged vesicles in water with added salt are widespread in nature and industrial production. Here we investigate, via Brownian dynamics simulations, a model that grasps the key features of these systems, with bidisperse colloidal beads interacting via a hard-core and an electrostatic double layer potential. Our goal is to focus on a set of interaction parameters that is not generic but measured in recent experiments, and relevant for a class of consumer products, such as liquid fabric softeners. On increasing the volume fraction in a range relevant to real formulation, we show that the dynamics become progressively slower and heterogeneous, displaying the typical signatures of an approaching glass transition. On lowering the salt concentration, which corresponds to increasing the strength and range of the electrostatic repulsion, the emergence of glassy dynamics becomes significantly steeper, and, remarkably, occurs at volume fractions well below the hard-sphere glass transition. The volume fraction dependence of the structural relaxation time at different salt concentration is well described through a functional law inspired by a recently proposed model (Krausser et al 2015 Proc. Natl Acad. Sci. USA 112 13762). According to our results, the investigated system may be thought of as a Wigner glass, i.e. a low-density glassy state stabilized by long-range repulsive interactions. Overall, our study suggests that glassy dynamics plays an important role in controlling the stability of these suspensions.

4.
Rev. chil. obstet. ginecol ; 79(3): 218-228, jun. 2014. ilus, tab
Artículo en Español | LILACS | ID: lil-720217

RESUMEN

El embarazo está marcado por cambios y adaptaciones cardiovasculares que son importantes para el crecimiento y mantenimiento de la placenta y el feto. Durante este periodo, las adaptaciones vasculares uterinas manifiestan cambios clasificados como de corto o largo plazo los cuales están relacionados con adaptaciones vasodilatadoras, angiogénicas o de remodelación. El estrógeno y los receptores estrogénicos clásicos (REs), RE-alfa y RE-beta, han demostrado ser parcialmente responsables por facilitar el incremento dramático en el fluido sanguíneo uterino necesario durante el embarazo. En ésta revisión bibliográfica se discuten la base estructural para la diversidad y selectividad funcional de los REs por el estrógeno, el papel de los REs sobre los efectos genómicos y no-genómicos en células endoteliales de arterias uterinas (CEAU). Estos temas integran el conocimiento científico sobre la regulación molecular de CEAU para mantener el incremento fisiológico en la perfusión útero-placentaria observada durante un embarazo normal.


Pregnancy is marked by changes and cardiovascular adaptations that are important for the maintenance and growth of the placenta and fetus. During this period, the uterine vascular adaptations manifest changes that can be classified as short or long term and they related to adaptations for vasodilation, angiogenic or remodeling. Estrogen and the classical estrogen receptors (ERs), ER-alpha and ER-beta, have been shown to be partially responsible for facilitating this dramatic increase in uterine blood flow needed during pregnancy. This literature review discusses the basis for structural diversity and functional selectivity of ERs by estrogen, the role of ERs on the genomic and non-genomic effects in endothelial cells of uterine arteries (UAEC). These themes integrate scientific knowledge about the molecular regulation of UAEC to maintain the physiological increase in uteroplacental perfusion observed during normal pregnancy.


Asunto(s)
Humanos , Femenino , Embarazo , Endotelio Vascular , Estrógenos , Neovascularización Fisiológica , Receptores de Estrógenos , Útero/irrigación sanguínea , Componentes Genómicos , Ligandos
5.
Rev Chil Obstet Ginecol ; 79(3): 218-228, 2014 Jun.
Artículo en Español | MEDLINE | ID: mdl-26113751

RESUMEN

Pregnancy is marked by changes and cardiovascular adaptations that are important for the maintenance and growth of the placenta and fetus. During this period, the uterine vascular adaptations manifest changes that can be classified as short or long term and they related to adaptations for vasodilation, angiogenic or remodeling. Estrogen and the classical estrogen receptors (ERs), ER-α and ER-ß, have been shown to be partially responsible for facilitating this dramatic increase in uterine blood flow needed during pregnancy. This literature review discusses the basis for structural diversity and functional selectivity of ERs by estrogen, the role of ERs on the genomic and non-genomic effects in endothelial cells of uterine arteries (UAEC). These themes integrate scientific knowledge about the molecular regulation of UAEC to maintain the physiological increase in uteroplacental perfusion observed during normal pregnancy.

6.
Rev Chil Obstet Ginecol ; 79(2): 129-139, 2014.
Artículo en Español | MEDLINE | ID: mdl-26113750

RESUMEN

Estrogen and classical estrogen receptors (ERs), ER-α and ER-ß, have been shown to be partially responsible for short and long term uterine endothelial adaptations during pregnancy. The molecular and structural differences, together with the various effects caused by these receptors in cells and tissues, suggest that their function varies depending upon estrogen and estrogen receptor signaling. In this review, we discuss the role of estrogen and its classic receptors in the cardiovascular adaptations during pregnancy and the expression of ERs in vivo and in vitro in the uterine artery endothelium during the ovarian cycle and pregnancy, while comparing their expression in arterial endothelium from reproductive and non-reproductive tissues. These themes integrate current knowledge of this broad scientific field with various interpretations and hypothesis that related estrogenic effects by either one or both ERs. This review also includes the relationship with vasodilator and angiogenic adaptations required to modulate the dramatic physiological increase to the uteroplacental perfusion observed during normal pregnancy.

7.
Rev. chil. obstet. ginecol ; 79(2): 129-139, 2014. ilus, graf
Artículo en Español | LILACS | ID: lil-714349

RESUMEN

El estrógeno y los receptores estrogénicos clásicos (REs), RE- alfa y RE-beta, han demostrado ser parcialmente responsable por las adaptaciones endoteliales uterinas durante el embarazo al corto y largo plazo. Las diferencias moleculares y estructurales, junto con los diferentes efectos causados por estos receptores en las células y los tejidos, sugieren que su función varía dependiendo de la manera en la cual el estrógeno se comunica con sus receptores. En ésta revisión bibliográfica se discuten la función del estrógeno y sus receptores clásicos en las adaptaciones cardiovasculares durante el embarazo y la expresión de los Res in vivo e in vitro en el endotelio de la arteria uterina durante el ciclo ovárico y el embarazo, a la vez comparado con la expresión en endotelio arterial de tejidos reproductivos y no reproductivos. Estos temas integran el conocimiento actual de este amplio campo científico con interpretaciones e hipótesis diversas relacionadas con los efectos estrogénicos mediados bien sea por uno o los dos REs. Esta revisión también incluye la relación con las adaptaciones vasodilatadoras y angiogénicas requeridas para modular el dramático incremento fisiológico en la perfusión útero-placentaria observada durante un embarazo normal.


Estrogen and classical estrogen receptors (ERs), ER- alpha and ER- beta, have been shown to be partially responsible for short and long term uterine endothelial adaptations during pregnancy. The molecular and structural differences, together with the various effects caused by these receptors in cells and tissues, suggest that their function varies depending upon estrogen and estrogen receptor signaling. In this review, we discuss the role of estrogen and its classic receptors in the cardiovascular adaptations during pregnancy and the expression of ERs in vivo and in vitro in the uterine artery endothelium during the ovarian cycle and pregnancy, while comparing their expression in arterial endothelium from reproductive and non-reproductive tissues. These themes integrate current knowledge of this broad scientific field with various interpretations and hypothesis that related estrogenic effects by either one or both ERs. This review also includes the relationship with vasodilator and angiogenic adaptations required to modulate the dramatic physiological increase to the uteroplacental perfusion observed during normal pregnancy.


Asunto(s)
Humanos , Femenino , Embarazo , Endotelio Vascular , Estrógenos/fisiología , Receptores de Estrógenos/fisiología , Útero/irrigación sanguínea , Western Blotting , Inmunohistoquímica , Neovascularización Fisiológica , Receptor alfa de Estrógeno/fisiología , Receptor beta de Estrógeno/fisiología
8.
J Endocrinol Invest ; 36(2): 92-6, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22398397

RESUMEN

Glucocorticoid-induced osteoporosis (GIO) is the most frequent cause of secondary osteoporosis. GIO is linked to glucocorticoids (GC) daily assumption with maximum effect within first months of treatment and decreasing to basal levels as the therapy is discontinued. In Italy, primary prevention of GIO is suggested when GC therapy (prednisone >5 mg/day or equivalent) is taken for longer than 3 months. Lazio GISMO (Italian Group for Study and Diagnosis of Bone Metabolism Diseases) group organized the GC and Osteoporosis Epidemiology study (EGEO) to evaluate physician's approach in preventing GIO. The study involved 19 osteoporosis centers. Patients taking long-term GC therapy were recruited and information collected: medical history and anthropometric data, GC therapy, primary disease, physician's specialty, osteopororosis screening, and pharmacological intervention. The study included 1334 patients. Mean age was 63 ± 13 yr; 243 (18%) patients had a history of falls from standing position in the previous 12 months, 78 (35%) vertebral fractures, 91 (41%) fractures other than vertebral, 27 (12%) femoral fractures, and 27 (12%) multiple sites fractures. The molecules of GC more often prescribed were prednisone and 6-metil prednisolone. One thousand and forty patients (78%) were taking GC for more than 6 months. GC therapy was prescribed more frequently by rheumatologists (62%). Antiosteoporotic drugs for GIO prevention were prescribed in 431 patients (32%). Among the patients, only 27% (360) received calcium and vitamin D supplements, and 39% (319) treated by rheumatologists received anti-resorptive drugs. In conclusion, our data show that in Italy, as already described elsewhere, only a small subpopulation of GC-treated patients was supported by an anti-osteoporotic therapy, indicating the need to further stimulate awareness of both patients and specialists, prescribing GC therapy, to an appropriate and prompt GIO prevention.


Asunto(s)
Glucocorticoides/efectos adversos , Osteoporosis/inducido químicamente , Osteoporosis/prevención & control , Adulto , Anciano , Anciano de 80 o más Años , Densidad Ósea/efectos de los fármacos , Densidad Ósea/fisiología , Estudios de Cohortes , Femenino , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Osteoporosis/epidemiología , Estudios Prospectivos , Adulto Joven
9.
Clin Microbiol Infect ; 15(6): 552-9, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19416294

RESUMEN

Uncertainty persists about risk factors for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections in Europe and the long-term efficacy of decolonization strategies. To evaluate risk factors for CA-MRSA in Geneva, Switzerland, a hospital-based, retrospective case-control study of 26 patients with CA-MRSA infection and 60 control patients was performed. To evaluate the long-term effect of a systematic decolonization strategy (with and without concomitant systemic antibiotic therapy) for CA-MRSA patients, a prospective cohort study of 79 patients with Panton-Valentine leukocidin-producing CA-MRSA isolates was conducted. Nationality other than European Union or Swiss (adjusted OR 6.09; 95% CI 1.07-34.65) and absence of healthcare contact (adjusted OR 0.11, 95% CI 0.02-0.59) were independent predictors of CA-MRSA infection. Forty-five cases were followed (median, 22 months) to assess the long-term efficacy of the decolonization strategy; 39/45 (86.7%) had no clinical relapse and were MRSA-negative at their last follow-up, whereas six remained MRSA-positive. Five of these six cases belonged to a family cluster. Decolonization rates were similar between infected patients and asymptomatic carriers (92.6% vs. 77.8%, p = 0.20). This study shows a lack of readily modifiable risk factors for CA-MRSA infection in this population, and suggests the potential usefulness of conducting decolonization procedures in a setting with sporadic CA-MRSA infection. Further studies are needed to elucidate the role of migration as a factor contributing to the emergence of CA-MRSA in Europe.


Asunto(s)
Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/microbiología , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Adulto , Portador Sano/tratamiento farmacológico , Portador Sano/epidemiología , Portador Sano/microbiología , Estudios de Casos y Controles , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Infecciones Estafilocócicas/tratamiento farmacológico , Suiza/epidemiología , Adulto Joven
10.
Euro Surveill ; 13(37)2008 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-18801315

RESUMEN

Salmonella serovar Stanley is rare in Europe. In Switzerland, the number of reported isolates has increased from 2 in 2000 to 25 in 2005. A nationwide outbreak of gastrointestinal illness due to S. Stanley occurred from September 2006 through February 2007. Eighty-two cases were documented. Males were 56%; mean age of the cases was 45.7 years (range 0-92). Forty-seven cases (57%) occurred in three western cantons: Vaud, Bern, and Geneva. Twenty-three cases (28%) were hospitalised. In the case-control study conducted to find the source of the outbreak, cases were more likely than controls to have eaten local soft cheese (OR 11.4, p=0.008). One clone of S. Stanley strain was isolated from soft cheese and from 77 cases (94%) who reported no history of having travelled abroad. The outbreak ended after the withdrawal of the cheese from the market. This is the first S. Stanley outbreak in Switzerland and the first in Europe unrelated to imported products, suggesting an increased local circulation of this previously rare serotype.


Asunto(s)
Queso/microbiología , Brotes de Enfermedades , Infecciones por Salmonella/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Bacteriemia/epidemiología , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Salmonella/aislamiento & purificación , Suiza/epidemiología
11.
Clin Ter ; 159(1): 5-12, 2008.
Artículo en Italiano | MEDLINE | ID: mdl-18399255

RESUMEN

AIM: The diagnosis of acute coronary syndrome (ACS), non-ST-elevation myocardial infarction and unstable angina in the emergency department (ED) remains a challenge. The aim of our study was to investigate quality and the diagnostic accuracy of 16-MDCT coronary angiography, detecting coronary artery lesions in patients with suspected ACS presented in ED. MATERIALS AND METHODS: We studied with 16-MDCT (Sensation 16, Siemens, Forchleim, Germania) and coronary angiography 37 patients with the following inclusion criteria: chest pain compatible with myocardial ischemia, normal or no-diagnostic ECG changes and initial concentrations of serum troponin-I < or =1 ng/ml. The 16-MDCT was performed with ECG-gated technique after the intravenous administration of 90-100 ml of iodinated contrast material followed by a saline bolus. The scan parameters were: 120 kV, 650-720 mAs, 16 x 0.75mm collimation, 0.42s rotation time, 3 mm (pitch 0.25) feed/rot, B30f kernel. We evaluated for each patient: image quality and different artefacts, plaques identification and characterization. RESULTS: The evaluation of the image quality was based on a total of 453 segments, of which 415 segments (92.2%) were considered to have diagnostic image quality. MDCT correctly detected 15 patients with at least 1 stenosis >50% and correctly ruled out significant coronary artery disease in 19 patients with 1 FP and 2 FN: sensitivity 88%, specificity 95%, PPV 94%, NPV 90%. The plaques were hard in 6 cases, mixt in 16 cases and soft in 14 cases, respectively. CONCLUSIONS: Our results point-out that 16-MDCT in ED has the real ability to detect and rule out significant coronary stenoses in patients with ACS.


Asunto(s)
Síndrome Coronario Agudo/diagnóstico por imagen , Angiografía Coronaria/métodos , Servicio de Urgencia en Hospital , Tomografía Computarizada por Rayos X , Síndrome Coronario Agudo/diagnóstico , Medios de Contraste/farmacología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/métodos
12.
J Endocrinol Invest ; 28(3 Suppl): 3-7, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16042354

RESUMEN

The quest for eternal youth has been prevalent in civilised societies in many cultures for many centuries. Preventing or deferring the disabilities and morbidities associated with aging through judicious pharmacotherapy has become a particularly relevant healthcare target with the rapid and relentless global demographic shift towards an increasingly elderly population in the 21th century. Aging men commonly loose muscle, become frail, have impaired sexual and cognitive functions, low mood, develop osteopenia and/or osteoporosis with increased risk for fractures and gain visceral fat which predisposes to diabetes, dyslipidaemia, and ischemic heart disease. These alterations in body function are reminiscent of states of androgen deficiency in younger patients. Indeed, aging is associated with a progressive age-related but variable decline in sex hormones. This condition has been named partial androgen deficiency in aging men (PADAM) and consists in a gradual decline in sex hormone levels over years resulting in physical and psychological changes as depression, impotence, decreased sex drive, loss of muscle tone or strength and lethargy. In this review we have tried to give a real identity to PADAM and quantify its entitiy, using the power of the epidemiology.


Asunto(s)
Envejecimiento , Andrógenos/deficiencia , Anciano , Anciano de 80 o más Años , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/epidemiología , Epidemiología , Humanos , Hipogonadismo/complicaciones , Masculino , Obesidad/complicaciones , Obesidad/epidemiología , Factores de Riesgo
13.
Ann Ig ; 17(2): 129-38, 2005.
Artículo en Italiano | MEDLINE | ID: mdl-16676733

RESUMEN

A growing desire among women to move away from interventions and hospitals to more "natural" childbirth has emerged over several years. The role and autonomy of midwives, a favourable opinion among women about home childbirth and better cooperation between hospitals and district health facilities are all fundamental in order to implement a home birth project. The opinion of women about "planned" home birth was investigated in the Puglia region through a survey conducted among a sample of women who had just delivered in hospital and a representative sample of the general female population. From 20 to 30% of women in the Puglia region would be basically in favour of home birth project. The main difference between the two groups of women concern the higher proportion of caesarean deliveries among mothers who had just delivered and their demand for more specific training of involved health personnel. Both samples are agreed on the specific training of women during pregnancy and on the presence of a specialist during home delivery. The results of the investigation seem to be in favour of planning a home birth project in the Puglia region.


Asunto(s)
Parto Domiciliario , Partería/normas , Opinión Pública , Mujeres , Adolescente , Adulto , Conducta de Elección , Femenino , Encuestas de Atención de la Salud , Humanos , Entrevistas como Asunto , Italia , Persona de Mediana Edad , Embarazo , Factores de Riesgo , Encuestas y Cuestionarios
14.
Surg Endosc ; 19(1): 133-6, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15549632

RESUMEN

BACKGROUND: Laparoscopy is a technique used in various surgical procedures. Few studies in the literature compare stress between laparoscopic and open surgery used for esophagogastric surgical procedures. Pulmonary function is known to be significantly affected in open surgeries, increasing postoperative morbidity and mortality. The current study aimed to assess pulmonary function in patients before and after open and laparoscopic esophagogastric surgery. METHODS: For this study, 75 patients were divided into two groups: 50 patients undergoing laparoscopy and 25 patients undergoing open surgery. The following parameters were determined by spirometry before and after surgery: forced expiratory volume in the first second (FEV(1)), forced vital capacity (FVC), and forced expiratory flow in the midexpiratory phase (FEF(25-75%)). RESULTS: A decrease in FEV(1,) FVC, and FEF((25-75%)) was observed in the two groups on postoperative days 2, 3, and 4, as compared with the preoperative period. Likewise, FEV(1) and FVC showed a significant reduction on postoperative days 2, 3, and 4 in the patients who underwent to open surgery, but only on the day 2 in those who underwent to laparoscopic surgery. A significant decrease in FEF((25-75%)) was observed only on postoperative day 2 in the group that underwent open surgery. Significant differences in FEV(1) between the groups were observed on postoperative days 2, 3, and 4. No significant difference in FVC was noted between the groups, and a difference in FEF((25-75%)) was observed only on postoperative day 4. CONCLUSIONS: Postoperative pulmonary dysfunction was more important for the patients undergoing open surgery than for those undergoing laparoscopic surgery.


Asunto(s)
Acalasia del Esófago/cirugía , Volumen Espiratorio Forzado , Reflujo Gastroesofágico/cirugía , Laparoscopía , Flujo Espiratorio Medio Máximo , Capacidad Vital , Procedimientos Quirúrgicos del Sistema Digestivo , Acalasia del Esófago/fisiopatología , Reflujo Gastroesofágico/fisiopatología , Humanos , Cuidados Posoperatorios , Cuidados Preoperatorios , Estudios Prospectivos
15.
J Endocrinol Invest ; 26(7 Suppl): 107-13, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14604073

RESUMEN

The maturation and physiologic functions of male sexual apparatus are under the control of the hypothalamic-pituitary-gonadal (HPG) axis. The determination of gonadotropins and testosterone as secretory products of pituitary and gonads, respectively, represents the first step in the evaluation of male sexual function and the diagnosis of disorders in male reproductive axis. However, there are several clinical situations that require a dynamic evaluation of this system and the measurement of basal gonadotropins and testosterone must be combined with specific dynamic tests. These mainly consist in GnRH stimulation, which evaluates the endocrine reserve capacity of the pituitary, and human chorionic gonadotropin (hCG) stimulation, which is used in the assessment of Leydig cells activity. The paper illustrates the technical aspects, the normal/pathological responses and the role of these two tests in assessing the male HPG axis in respect to different clinical diagnostic queries.


Asunto(s)
Hormona Liberadora de Gonadotropina , Enfermedades Testiculares/diagnóstico , Testosterona/sangre , Adolescente , Adulto , Envejecimiento/fisiología , Gonadotropina Coriónica , Retroalimentación Fisiológica , Hormona Folículo Estimulante/sangre , Enfermedades de los Genitales Masculinos/diagnóstico , Enfermedades de los Genitales Masculinos/fisiopatología , Hormona Liberadora de Gonadotropina/sangre , Humanos , Hipogonadismo/diagnóstico , Hipogonadismo/fisiopatología , Sistema Hipotálamo-Hipofisario/fisiopatología , Hormona Luteinizante/sangre , Masculino , Persona de Mediana Edad , Pubertad Tardía/diagnóstico , Pubertad Tardía/fisiopatología , Enfermedades Testiculares/fisiopatología , Varicocele/diagnóstico
16.
Blood ; 98(10): 3050-7, 2001 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-11698290

RESUMEN

Chronic lymphocytic leukemia (CLL) is an incurable leukemia characterized by the slow but progressive accumulation of cells in a CD5+ B-cell clone. Like the nonmalignant counterparts, B-1 cells, CLL cells often express surface immunoglobulin with the capacity to bind autologous structures. Previously there has been no established link between antigen-receptor binding and inhibition of apoptosis in CLL. In this work, using primary CLL cells from untreated patients with this disease, it is demonstrated that engagement of surface IgM elicits a powerful survival program. The response includes inhibition of caspase activity, activation of NF-kappaB, and expression of mcl-1, bcl-2, and bfl-1 in the tumor cells. Blocking phosphatidylinositol 3-kinase (PI3-K), a critical mediator of signals through the antigen receptor, completely abrogated mcl-1 induction and impaired survival in the stimulated cells. These data support the contention that CLL cell survival is promoted by antigen for which the malignant clone has affinity, and suggest that pharmacologic interference with antigen-receptor-derived signals has potential for therapy in patients with CLL.


Asunto(s)
Linfocitos B/patología , Inmunoglobulina M/fisiología , Leucemia Linfocítica Crónica de Células B/patología , Proteínas de Neoplasias/fisiología , Células Madre Neoplásicas/patología , Receptores de Antígenos de Linfocitos B/fisiología , Anciano , Anciano de 80 o más Años , Apoptosis , Linfocitos B/inmunología , Western Blotting , Antígenos CD40/fisiología , Antígenos CD5/análisis , Supervivencia Celular , Ensayo de Cambio de Movilidad Electroforética , Femenino , Regulación Leucémica de la Expresión Génica , Humanos , Masculino , Microscopía Fluorescente , Persona de Mediana Edad , Antígenos de Histocompatibilidad Menor , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , FN-kappa B/metabolismo , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/genética , Células Madre Neoplásicas/inmunología , Fosfatidilinositol 3-Quinasas/fisiología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Proteínas Proto-Oncogénicas c-bcl-2/genética , ARN Mensajero/biosíntesis , ARN Neoplásico/biosíntesis , Proteína bcl-X
17.
Artículo en Inglés | MEDLINE | ID: mdl-11570763

RESUMEN

Tunable surface acoustic wave (SAW) filters (TSF) have been widely used in the wireless telecommunication systems. A prototype of a multi-IDT (interdigital transducer) input TSF has been developed. The device consists of 11 IDT paralleled in the SAW propagation path. Different SAW filter configurations are realized by selecting or combining various IDTs, resulting in the tunability of both center frequency and 3 dB bandwidth. The center frequencies of the SAW filter range from 126.8 to 199.1 MHz; the 3 dB bandwidths range from 15.2 to 58.9 MHz. Impedance weighting methods have been applied. The passband ripple has been reduced from 6.44 to 1.37 dB after resistance weighting.

18.
Artículo en Inglés | MEDLINE | ID: mdl-11570769

RESUMEN

A typical low noise oscillator uses a crystal resonator as the frequency-determining element. An understanding of the fundamental nature of acceleration sensitivity in crystal oscillators resides primarily in understanding the behavior of the crystal resonator. The driving factor behind the acceleration-induced frequency shift is shown to be deformation of the resonator. The deformation drives two effects: an essentially linear change in the frequency-determining dimensions of the resonator and an essentially nonlinear effect of changing the velocity of the propagating wave. In this paper, the fundamental nature of acceleration sensitivity is reviewed and clarified, and attendant design guidance is developed for piezoelectric resonators. The basic properties of acceleration sensitivity and general design guidance are developed through the simple examples of "bulk acoustic wave (BAW) in a box" and "surface transverse wave (STW) in a box." These examples serve to clarify a number of concepts, including the role of mode shape and the basic difference between the BAW and STW cases. The design equations clarify the functional dependencies of the acceleration sensitivities on the full range of crystal resonator design and fabrication parameters.

20.
Percept Psychophys ; 62(6): 1243-57, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11019620

RESUMEN

Recent auditory research using sequentially presented, spatially fixed tones has found evidence that, as in vision for simultaneous, spatially distributed objects, attention appears to be important for the integration of perceptual features that enable the identification of auditory events. The present investigation extended these findings to arrays of simultaneously presented, spatially distributed musical tones. In the primary tasks, listeners were required to search for specific cued conjunctions of values for the features of pitch and instrument timbre. In secondary tasks, listeners were required to search for a single cued value of either the pitch or the timbre feature. In the primary tasks, listeners made frequent errors in reporting the presence or absence of target conjunctions. Probability modeling, derived from the visual search literature, revealed that the error rates in the primary tasks reflected the relatively infrequent failure to correctly identify pitch or timbre features, plus the far more frequent illusory conjunction of separately presented pitch and timbre features. Estimates of illusory conjunction rate ranged from 23% to 40%. Thus, a process must exist in audition that integrates separately registered features. The implications of the results for the processing of isolated auditory features, as well as auditory events defined by conjunctions of features, are discussed.


Asunto(s)
Percepción Auditiva/fisiología , Percepción Espacial/fisiología , Señales (Psicología) , Humanos , Modelos Estadísticos
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