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1.
Clin Radiol ; 77(9): 694-700, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35811155

RESUMEN

AIM: To compare the detection rate of magnetic resonance imaging (MRI) and ultrasound relative to endometrial biopsy for endometrial abnormalities in both pre- and post-menopausal women. MATERIALS AND METHODS: The present study was an institutional review board-approved, single-institution retrospective analysis of patients who underwent pelvic MRI within 1 year of diagnostic-quality biopsies from 2008-2018 (n=668). There were 303 patients who received uterine artery embolisation (UAE) and 478 patients who received pelvic ultrasound within the study period. Medical records were evaluated for radiological-histopathological correlation, demographics, laboratory studies, and clinical follow-up. RESULTS: In this cohort of 668 patients, there were 37 biopsies positive for malignancy; women with malignancy were older (58 versus 47 years, p<0.0001) and more likely to be post-menopausal (66% versus 12%, p<0.0001). There were 303 patients who underwent UAE and underwent a diagnostic-quality endometrial biopsy during the pre-procedural evaluation, none of whom were post-menopausal and had a mean age of 45 years. In women with abnormal uterine bleeding (AUB) or post-menopausal bleeding (PMB), the sensitivity of MRI for detecting endometrial cancer was 96.2%, with a negative predictive value (NPV) of 99.8%, compared to 68% and 97% for ultrasound, respectively. The receiver operating characteristic (ROC) curve of pre-biopsy MRI in identifying pre-malignant and malignant endometrial pathology demonstrated an AUC of 0.8920 (p<0.0001). CONCLUSION: In women with AUB or PMB, MRI has a 99.8% NPV in ruling out endometrial cancer. Further consideration should be made towards optimising pre-procedural evaluation for UAE.


Asunto(s)
Neoplasias Endometriales , Pólipos , Embolización de la Arteria Uterina , Enfermedades Uterinas , Neoplasias Uterinas , Biopsia , Neoplasias Endometriales/diagnóstico por imagen , Neoplasias Endometriales/patología , Neoplasias Endometriales/terapia , Endometrio/diagnóstico por imagen , Endometrio/patología , Femenino , Humanos , Persona de Mediana Edad , Pólipos/diagnóstico , Pólipos/patología , Estudios Retrospectivos , Enfermedades Uterinas/diagnóstico por imagen , Enfermedades Uterinas/patología , Hemorragia Uterina/patología
2.
Sci Rep ; 12(1): 4068, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-35260698

RESUMEN

We performed magnetic resonance spectroscopy (MRS) on healthy individuals with tinnitus and no hearing loss (n = 16) vs. a matched control group (n = 17) to further elucidate the role of excitatory and inhibitory neurotransmitters in tinnitus. Two-dimensional J-resolved spectroscopy (2D-JPRESS) was applied to disentangle Glutamate (Glu) from Glutamine and to estimate GABA levels in two bilateral voxels in the primary auditory cortex. Results indicated a lower Glu concentration (large effect) in right auditory cortex and lower GABA concentration (medium effect) in the left auditory cortex of the tinnitus group. Within the tinnitus group, Glu levels positively correlated with tinnitus loudness measures. While the GABA difference between groups is in line with former findings and theories about a dysfunctional auditory inhibition system in tinnitus, the novel finding of reduced Glu levels came as a surprise and is discussed in the context of a putative framework of inhibitory mechanisms related to Glu throughout the auditory pathway. Longitudinal or interventional studies could shed more light on interactions and causality of Glu and GABA in tinnitus neurochemistry.


Asunto(s)
Corteza Auditiva , Acúfeno , Ácido Glutámico/metabolismo , Humanos , Espectroscopía de Resonancia Magnética/métodos , Ácido gamma-Aminobutírico/metabolismo
3.
Clin Neurophysiol ; 132(7): 1694-1707, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34038848

RESUMEN

OBJECTIVE: To investigate oscillatory brain activity changes following acoustic stimulation in tinnitus and whether these changes are associated with behavioral measures of tinnitus loudness. Moreover, differences in ongoing brain activity between individuals with and without residual inhibition (RI) are examined (responders vs. non-responders). METHODS: Three different types of noise stimuli were administered for acoustic stimulation in 45 tinnitus patients. Subjects resting state brain activity was recorded before and after stimulation via EEG alongside with subjective measurements of tinnitus loudness. RESULTS: Delta, theta and gamma band power increased, whereas alpha and beta power decreased from pre to post stimulation. Acoustic stimulation responders exhibited reduced gamma and a trend for enhanced alpha activity with the latter localized in the right inferior temporal gyrus. Post stimulation, individuals experiencing RI showed higher theta, alpha and beta power with a peak power difference in the alpha band localized in the right superior temporal gyrus. Neither correlations with behavioral tinnitus measures nor stimulus-specific changes in EEG activity were present. CONCLUSIONS: Our observations might be indicative of trait-specific forms of oscillatory signatures in different subsets of the tinnitus population related to acoustic tinnitus suppression. SIGNIFICANCE: Results and insights are not only useful to understand basic neural mechanisms behind RI but are also valuable for general neural models of tinnitus.


Asunto(s)
Estimulación Acústica/métodos , Electroencefalografía/métodos , Inhibición Neural/fisiología , Acúfeno/diagnóstico , Acúfeno/fisiopatología , Adulto , Anciano , Audiometría/métodos , Ondas Encefálicas/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
4.
Sci Rep ; 11(1): 2243, 2021 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-33500489

RESUMEN

Tinnitus is the chronic perception of a phantom sound with different levels of related distress. Past research has elucidated interactions of tinnitus distress with audiological, affective and further clinical variables. The influence of tinnitus distress on cognition is underinvestigated. Our study aims at investigating specific influences of tinnitus distress and further associated predictors on cognition in a cohort of n = 146 out-ward clinical tinnitus patients. Age, educational level, hearing loss, Tinnitus Questionnaire (TQ) score, tinnitus duration, speech in noise (SIN), stress, anxiety and depression, and psychological well-being were included as predictors of a machine learning regression approach (elastic net) in three models with scores of a multiple choice vocabulary test (MWT-B), or two trail-making tests (TMT-A and TMT-B), as dependent variables. TQ scores predicted lower MWT-B scores and higher TMT-B test completion time. Stress, emotional, and psychological variables were not found to be relevant predictors in all models with the exception of small positive influences of SIN and depression on TMT-B. Effect sizes were small to medium for all models and predictors. Results are indicative of specific influence of tinnitus distress on cognitive performance, especially on general or crystallized intelligence and executive functions. More research is needed at the delicate intersection of tinnitus distress and cognitive skills needed in daily functioning.


Asunto(s)
Cognición/fisiología , Ruido , Anciano , Humanos , Aprendizaje Automático , Persona de Mediana Edad , Encuestas y Cuestionarios , Acúfeno/fisiopatología
5.
HNO ; 66(3): 198-204, 2018 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-29143096

RESUMEN

Neurofeedback is a noninvasive neuromodulation technique employing real-time display of brain activity in terms of electroencephalography (EEG) signals to teach self-regulation of distinct patterns of brain activity or influence brain activity in a targeted manner. The benefit of this approach for control of symptoms in attention deficit disorders, hyperactivity, depression, and migraine has been proven. Studies in recent years have also repeatedly shown this treatment to improve tinnitus symptoms, although it has not become established as routine therapy. The primary focus of this review is the rational of EEG neurofeedback for tinnitus treatment and the currently available data from published studies. Furthermore, alternative neurofeedback protocols using real-time functional magnetic resonance imaging (fMRI) measurements for tinnitus control are considered. Finally, this article highlights how modern EEG analysis (source localization, connectivity) and the improving understanding of tinnitus pathology can contribute to development of more focused neurofeedback protocols for more sustainable control of tinnitus.


Asunto(s)
Neurorretroalimentación , Acúfeno , Depresión , Electroencefalografía , Humanos , Acúfeno/terapia
6.
AIDS ; 27(16): 2637-48, 2013 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-23863402

RESUMEN

OBJECTIVE: To analyse trends in under-five mortality rate in South Africa (1990-2011), particularly the contribution of AIDS deaths. METHODS: Three nationally used models for estimating AIDS deaths in children were systematically reviewed. The model outputs were compared with under-five mortality rate estimates for South Africa from two global estimation models. All estimates were compared with available empirical data. RESULTS: Differences between the models resulted in varying point estimates for under-five mortality but the trends were similar, with mortality increasing to a peak around 2005. The three models showing the contribution of AIDS suggest a maximum of 37-39% of child deaths were due to AIDS in 2004-2005 which has since declined. Although the rate of progress from 1990 is not the 4.4% needed to meet Millennium Development Goal 4 for child survival, South Africa's average annual rate of under-five mortality decline between 2006 and 2011 was between 6.3 and 10.2%. CONCLUSION: In 2005, South Africa was one of only four countries globally with an under-five mortality rate higher than the 1990 Millennium Development Goal baseline. Over the past 5 years, the country has achieved a rate of child mortality reduction exceeded by only three other countries. This rapid turnaround is likely due to scale-up of prevention of mother-to-child transmission of HIV, and to a lesser degree, the expanded roll-out of antiretroviral therapy. Emphasis on these programmes must continue, but failure to address other aspects of care including integrated high-quality maternal and neonatal care means that the decline in child mortality could stall.


Asunto(s)
Mortalidad del Niño , Infecciones por VIH/epidemiología , Infecciones por VIH/mortalidad , Preescolar , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/prevención & control , Investigación sobre Servicios de Salud , Humanos , Lactante , Recién Nacido , Masculino , Sudáfrica/epidemiología
7.
J Vet Intern Med ; 27(6): 1551-4, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24627899

RESUMEN

BACKGROUND: Treatment of idiopathic headshaking in horses is complicated by an incomplete understanding of underlying pathophysiology and partially effective treatments. If an inflammatory etiology exists, corticosteroids could be beneficial. HYPOTHESIS: An anti-inflammatory dose of dexamethasone reduces the signs of idiopathic headshaking in a field setting. ANIMALS: Convenience sample of 20 adult horses with idiopathic headshaking syndrome. Cases were recruited from the general population and diagnosed by attending veterinarians. METHODS: Prospective, blinded clinical trial. Pulsed dosing was with oral dexamethasone (60 mg PO Q24h × 4 days, q3 weeks for 4 months) or placebo (inert paste). Owners were blinded and asked to score the headshaking from 0 to 4 (4 = most severe) 3 days per week. The change in headshaking scores (HS) over each treatment pulse was compared between groups by ordinal logistic regression. RESULTS: Twelve horses completed the trial. There was no significant difference between treated or placebo horses (P = .987). Sun (P ≤ .001), wind (P = .028), and exercise (P ≤ .045) significantly increased HS. CONCLUSIONS AND CLINICAL IMPORTANCE: No benefit of dexamethasone treatment was detected for idiopathic headshaking. The results confirmed previous reports of common triggers for headshaking behavior


Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Dexametasona/uso terapéutico , Cabeza/fisiopatología , Enfermedades de los Caballos/fisiopatología , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Dexametasona/administración & dosificación , Enfermedades de los Caballos/tratamiento farmacológico , Caballos , Modelos Logísticos , Estudios Prospectivos
8.
J Perinatol ; 29(10): 680-4, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19609308

RESUMEN

OBJECTIVE: Chronic hypertension (CHTN) is a risk factor for both intrauterine growth restriction (IUGR) as well as preeclampsia. This study was performed to: (1) describe the prevalence of IUGR in women with preeclampsia (with and without CHTN) compared with controls, (2) investigate the relationship between preeclampsia and maternal CHTN with IUGR, and (3) investigate the relationship between IUGR and severity of preeclampsia. STUDY DESIGN: A case-control study was performed. Cases were patients identified with preeclampsia. Controls were patients presenting for delivery at term (>or=37 weeks). IUGR prevalence by case-control status, or severity of disease was evaluated using Pearson chi(2) tests. Multivariable logistic regression was used to control for confounders. RESULT: In all, 430 cases and 568 controls were studied. Preeclamptic women have a 2.7 (CI (1.94 to 3.86)) and 4.3 (CI (2.58 to 7.17)) times increased odds of having a fetus with IUGR at <10 and <5% compared with controls in adjusted analyses. There was a significant interaction between CHTN and IUGR. Therefore, in women without CHTN, women with PEC had increased odds of IUGR, whereas in women with CHTN, there was no difference in odds of IUGR in women with or without preeclampsia. Within the cases, severe preeclampsia was associated with IUGR<10% (AOR=1.82 (1.11 to 2.97)) but not IUGR<5% (AOR=1.6 (0.85 to 2.86)). CONCLUSION: Preeclampsia is independently associated with the development of IUGR. As suggested earlier, women with CHTN do not have the highest prevalence of IUGR, suggesting disparate pathways by which IUGR develops in women with superimposed preeclampsia compared with preeclampsia alone.


Asunto(s)
Retardo del Crecimiento Fetal/epidemiología , Preeclampsia/epidemiología , Estudios de Casos y Controles , Femenino , Humanos , Oportunidad Relativa , Embarazo , Prevalencia
9.
Handchir Mikrochir Plast Chir ; 38(1): 37-41, 2006 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-16538570

RESUMEN

This is a long-term follow-up analysis of patients who have been operated on for Thoracic Outlet Syndrome (TOS) at our clinic in order to evaluate the quality of therapy and the criteria of indications for surgery. 39 patients with a total of 45 surgical procedures were examined after a median follow-up of 8.8 years. The results in this study are based exclusively on the subjective outcome assessment by the patients themselves. Assessment of the long-term result in the "vascular TOS" group (13 cases = 29 %) was good in ten cases (77 %), fair in two cases (15 %) and poor in one case (8 %). In agreement with the literature, we were able to achieve the best results in this group. In the "true neurological TOS" group (28 cases = 62 %), assessment of the long-term result was good in 19 cases (68 %), fair in six cases (21 %) and poor in three cases (11 %). A clear tendency to a poor prognosis could be seen in women with a combination of cervical rib and fibrous band and a long delay between onset of symptoms and surgery. Assessment of long-term result in the "disputed TOS" group (four cases = 9 %) showed good results in three cases and a fair result in one case. In the absence of objective pathologies, only few and carefully selected patients were operated upon. The presented long-term results confirm the use of individual therapeutic concepts with special consideration of anatomy and clinical picture.


Asunto(s)
Síndrome del Desfiladero Torácico/cirugía , Adolescente , Adulto , Anciano , Síndrome de la Costilla Cervical/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Tiempo , Resultado del Tratamiento
10.
Br J Dermatol ; 150(4): 677-86, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15099363

RESUMEN

BACKGROUND: Baseline staging in patients with primary cutaneous malignant melanoma (MM) is routine, but the diagnostic accuracy and the impact on clinical outcome are still unclear. OBJECTIVES: To evaluate the sensitivity and specificity of baseline staging in the early detection of regional lymph node metastases or distant metastases in patients with MM. METHODS: One hundred consecutive patients with MM of Breslow's tumour thickness over 1.0 mm were enrolled. All patients had an extensive baseline staging including physical examination, ultrasound (US) of the abdomen and regional lymph nodes, chest X-ray, whole-body positron emission tomography (PET) and sentinel lymph node biopsy. The sensitivity and specificity of detection of macroscopic or microscopic metastases in the regional lymph nodes or at distant sites were calculated for each method. RESULTS: Sentinel lymph node biopsy was positive in 26 patients. US detected two of 26 histologically tumour-positive sentinel nodes (sensitivity 8%, specificity 88%) and PET two of 26 (sensitivity 8%; specificity 100%). There were three lymph node metastases with a diameter > 4 mm. All of them were found suspect at physical examination. Two of them were detectable with US, two with PET, and all were identified with either US or PET. Nine patients had suspect findings at distant sites, which were all false positive on further investigation (specificity of the combined staging procedures 91%). At 18 (6-37) months' follow-up, five of 26 (19%) patients with a positive sentinel node and four of 74 (5%) of patients with a negative sentinel node had recurrent or progressive disease. CONCLUSIONS: The combination of physical examination and lymph node US detects the great majority of patients with macroscopic lymph node metastasis (approximately 3% of patients at baseline). Only 10% of patients who have a histologically tumour-positive sentinel node are macroscopically detectable. Altogether, approximately 25% of patients have a positive sentinel node biopsy, among 90% microscopic. The value of whole body staging at baseline remains limited, since distant metastases can hardly ever be detected. The survival benefit of baseline staging and surveillance in patients with cutaneous MM remains to be established by comparative prospective trials.


Asunto(s)
Melanoma/patología , Estadificación de Neoplasias , Neoplasias Cutáneas/patología , Abdomen/diagnóstico por imagen , Adolescente , Adulto , Anciano , Reacciones Falso Positivas , Femenino , Humanos , Ganglios Linfáticos/diagnóstico por imagen , Metástasis Linfática , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Radiografía Torácica/métodos , Sensibilidad y Especificidad , Biopsia del Ganglio Linfático Centinela/métodos , Tomografía Computarizada de Emisión/métodos , Ultrasonografía
11.
Int J Gynaecol Obstet ; 83 Suppl 2: S45-S49, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29645208

RESUMEN

OBJECTIVE: To review the significance of a United States Food and Drug Administration (FDA) approved Phase I clinical trial of a new use for an old drug, quinacrine. To discover whether ultrasound may have utility in quinacrine sterilization (QS). METHOD: This clinical trial began on 16 September 2000 at the Women's and Children's Hospital of Buffalo (WCHOB) in Buffalo, New York. Ten patients volunteered to have QS. These subjects were carefully followed with regularly scheduled examinations, including extensive laboratory blood tests. In addition, each patient had a trans-abdominal ultrasound examination six weeks or later past the date of the second insertion of quinacrine. The trial was completed on 30 April 2003. RESULTS: Laboratory results fell within normal limits, thus providing additional evidence to affirm the lack of toxic effects of QS. With ultrasound, we were able to see scars in both oviducts on all of our patients. One patient with a small scar as seen on ultrasound became pregnant. CONCLUSION: QS was found to be safe and effective. Ultrasound holds the promise of reducing the failure rate.

12.
Int J Gynaecol Obstet ; 83 Suppl 2: S45-9, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14763185

RESUMEN

OBJECTIVE: To review the significance of a United States Food and Drug Administration (FDA) approved Phase I clinical trial of a new use for an old drug, quinacrine. To discover whether ultrasound may have utility in quinacrine sterilization (QS). METHOD: This clinical trial began on 16 September 2000 at the Women's and Children's Hospital of Buffalo (WCHOB) in Buffalo, New York. Ten patients volunteered to have QS. These subjects were carefully followed with regularly scheduled examinations, including extensive laboratory blood tests. In addition, each patient had a trans-abdominal ultrasound examination six weeks or later past the date of the second insertion of quinacrine. The trial was completed on 30 April 2003. RESULTS: Laboratory results fell within normal limits, thus providing additional evidence to affirm the lack of toxic effects of QS. With ultrasound, we were able to see scars in both oviducts on all of our patients. One patient with a small scar as seen on ultrasound became pregnant. CONCLUSION: QS was found to be safe and effective. Ultrasound holds the promise of reducing the failure rate.


Asunto(s)
Cicatriz/diagnóstico por imagen , Trompas Uterinas/efectos de los fármacos , Trompas Uterinas/diagnóstico por imagen , Quinacrina/efectos adversos , Sustancias para el Control de la Reproducción/efectos adversos , Esterilización Tubaria , Adulto , Implantes de Medicamentos , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Embarazo , Quinacrina/administración & dosificación , Sustancias para el Control de la Reproducción/administración & dosificación , Ultrasonografía , Estados Unidos , United States Food and Drug Administration
13.
J Oral Implantol ; 27(2): 63-72, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-12498429

RESUMEN

The purpose of this study was to (1) determine in vitro the effect of narrowing the buccolingual width of the occlusal table on the untightening torque required to loosen gold prosthetic screws after subjecting implants and implant-supported restorations to occlusal loads, and (2) to compare the incidence of screw loosening and values of untightening torque of the screws among crowns supported by 1 wide-diameter as opposed to 2 standard implants after loading in vitro. The restorations were divided into 4 groups (group 1, a narrow crown supported by one 5-mm wide-diameter implant; group 2, a narrow crown supported by 2 standard 3.75-mm-diameter implants; group 3, a wide crown supported by one 5-mm wide-diameter implant; and group 4, a wide crown supported by 2 standard 3.75-mm-diameter implants). A custom-designed chewing machine was used to simulate the grinding phase of the masticatory cycle and lateral excursions. The crowns were subjected to a 6-kg load for 16660 cycles over 5.5 hours and were loaded at the outer and inner inclines and cusp tips with an untightening loading pattern. The untightening torque was measured for the gold screws in the different groups before and after loading at 4 different locations for 8 cycles on the simulated chewing machine. A 1-way analysis of variance indicated a significant difference (P < .001) among the test groups. Pairwise multiple comparison tests (Scheffe) were carried out on mean "change scores." Group 3 was significantly different from the other groups, which were not significantly different from each other. Restoring missing molars with 1 wide-diameter implant had a greater incidence of screw loosening as compared with 2 implants. Narrowing the occlusal table of the restoration is critical when using 1 implant to support a missing molar. The untightening torque of gold screws was not affected by changing the width of the occlusal table of crowns supported by 2 implants.


Asunto(s)
Implantes Dentales de Diente Único , Diseño de Prótesis Dental , Retención de Prótesis Dentales/instrumentación , Prótesis Dental de Soporte Implantado , Análisis de Varianza , Coronas , Análisis del Estrés Dental , Humanos , Masticación , Diente Molar , Estadísticas no Paramétricas , Torque
14.
Biochim Biophys Acta ; 1473(2-3): 305-20, 1999 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-10594368

RESUMEN

Ht30/=Ht5). Cells with reduced mitochondrial activity also showed abnormal responses to the stimulation of NGF output. Thrombin and phorbol ester elevated NGF production from Ht100, Ht30 and Ht10 cells, but not from Ht5 cells. Ht30 cells, despite secreting less NGF basally than Ht100 cells, reached a similar or greater NGF output upon stimulation. Mitogens increased NGF output and NGF mRNA levels with the largest effect on NGF protein in Ht30 cells. Free radical production and the ability of cells to respond to NGF-inducing agents were related. These data suggest that chronic impairment of mitochondrial function associates with disturbances in cellular production of a signaling protein.


Asunto(s)
Mitocondrias/fisiología , Músculo Liso Vascular/metabolismo , Factor de Crecimiento Nervioso/biosíntesis , Animales , Línea Celular , Respiración de la Célula , Etidio/farmacología , Radicales Libres/análisis , Factor de Crecimiento Nervioso/genética , ARN Mensajero/biosíntesis , Ratas , Transducción de Señal/fisiología , Acetato de Tetradecanoilforbol/farmacología , Trombina/farmacología , Factores de Tiempo
15.
South Med J ; 92(12): 1194-8, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10624913

RESUMEN

We report the case of a 6-year-old boy who began to have fever and hypotension during the administration of a platelet transfusion. Subsequent investigation revealed the etiology to be bacterial contamination of the platelet product. Seratia marcescens was cultured from both the patient's blood and the platelet product. When fever and/or cardiorespiratory problems develop during the administration of blood products, possible bacterial contamination of the product must be considered so that appropriate therapy can be instituted. We discuss the etiology, possible preventive strategies, and the treatment of this problem.


Asunto(s)
Contaminación de Equipos , Transfusión de Plaquetas/efectos adversos , Choque Séptico/etiología , Eliminación de Componentes Sanguíneos , Donantes de Sangre , Niño , Contaminación de Equipos/prevención & control , Humanos , Masculino , Rabdomiosarcoma/terapia
16.
Brain Res Mol Brain Res ; 62(2): 167-74, 1998 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-9813306

RESUMEN

Altered nerve growth factor (NGF) regulation has been linked to the pathophysiology of hypertension. Vascular smooth muscle cells from an inbred hypertensive, but normoactive rat strain (WKHT) secreted NGF at a greater rate than from a hyperactive, normotensive strain (WKHA). Exposure to phorbol ester increased NGF secretion rates from WKHT by 400-800% but not from WKHA vascular muscle. NGF secretion rates from both WKHT and WKHA vascular cells were elevated by co-application of platelet-derived growth factor (PDGF) and transforming growth factor-beta1 (TGF-beta1) by 300-1000%. This response was partially attenuated by actinomycin D, an inhibitor of RNA transcription. These results suggest that regulation of NGF production does not occur solely at the level of transcription and post-transcriptional mechanisms operate. Analysis of NGF mRNA stability in the two strains following PDGF and TGF-beta1 treatment showed that NGF mRNA in WKHT had a half-life of 126.2+/-11.68 min while in WKHA vascular smooth muscle cells, the half-life was 47. 33+/-11.98 min. In addition to increased NGF mRNA stability in WKHT vascular muscle, these cells have an increased translational efficiency of NGF protein; elevated synthesis of NGF protein per unit NGF mRNA. Differences in signaling pathways may result in increased NGF mRNA stability and translational efficiency that may account for the elevated NGF protein in WKHT vascular smooth muscle cells.


Asunto(s)
Hipertensión/metabolismo , Músculo Liso Vascular/metabolismo , Factores de Crecimiento Nervioso/genética , Procesamiento Postranscripcional del ARN , ARN Mensajero/metabolismo , Animales , Aorta Torácica/citología , Células Cultivadas , Cruzamientos Genéticos , Hipercinesia/genética , Hipertensión/genética , Músculo Liso Vascular/inervación , Factores de Crecimiento Nervioso/metabolismo , Ratas , Ratas Endogámicas SHR/genética , Ratas Endogámicas WKY/genética , Ratas Mutantes , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Ácido Nucleico , Transducción de Señal
17.
Exp Cell Res ; 241(1): 186-93, 1998 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-9633527

RESUMEN

The spontaneously hypertensive rat (SHR) was developed as a genetic model of essential hypertension. In vivo and in vitro evidence demonstrates that vascular smooth muscle cells (VSMCs) from the SHR produce more nerve growth factor (NGF) than the normotensive Wistar-Kyoto (WKY) control strain. This increased NGF production is accompanied by excessive innervation of target tissues in the SHR. In the present study, a sensitive, competitive, quantitative, reverse-transcriptase polymerase chain reaction (C Q RT-PCR) assay is characterized and used to analyze levels of NGF mRNA in cultured VSMCs derived from the SHR and WKY strains as well as bladder tissue. Differences in NGF secretion rates between SHR and WKY VSMCs were partially due to an increased stability of NGF mRNA in SHR VSMCs. Following treatment with platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta 1) to elevate NGF production, the half-life of the NGF mRNA was 104.5 +/- 18.0 min in SHR VSMCs, compared to only 36.5 +/- 11.6 min in WKY VSMCs. Sequence analysis of the 3' untranslated region (UTR) revealed no strain differences in cis-acting sequences potentially involved in determining mRNA stability. Thus, it seems unlikely to be a 3'UTR mutation that prolongs mRNA lifetime. Rather, differential regulation of an RNA-binding protein may play a role in the abnormal NGF mRNA stability in SHR VSMCs. SHR VSMCs also demonstrate an increased translational efficiency of NGF protein; more NGF protein is synthesized per unit of NGF mRNA. The use of a C Q RT-PCR assay has allowed the determination that abnormal NGF mRNA stabilization as well as altered translational efficiency may contribute to excess NGF synthesis and progressive hypertension in the SHR.


Asunto(s)
Músculo Liso Vascular/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Ratas Endogámicas SHR/metabolismo , Animales , Células Cultivadas , Medio de Cultivo Libre de Suero/farmacología , Dactinomicina/farmacología , Músculo Liso/citología , Músculo Liso/metabolismo , Músculo Liso Vascular/citología , Músculo Liso Vascular/efectos de los fármacos , Mutación/genética , Factores de Crecimiento Nervioso/efectos de los fármacos , Factores de Crecimiento Nervioso/genética , Inhibidores de la Síntesis del Ácido Nucleico/farmacología , Factor de Crecimiento Derivado de Plaquetas/farmacología , Reacción en Cadena de la Polimerasa , Biosíntesis de Proteínas/efectos de los fármacos , Biosíntesis de Proteínas/genética , ARN Mensajero/antagonistas & inhibidores , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Endogámicas WKY , Secuencias Repetitivas de Ácidos Nucleicos/genética , Especificidad de la Especie , Transcripción Genética/efectos de los fármacos , Transcripción Genética/genética , Factor de Crecimiento Transformador beta/farmacología , Vejiga Urinaria/citología , Vejiga Urinaria/metabolismo
18.
Pacing Clin Electrophysiol ; 20(5 Pt 1): 1354-8, 1997 May.
Artículo en Inglés | MEDLINE | ID: mdl-9170137

RESUMEN

P wave electrogram amplitudes and atrial stimulation thresholds were determined in eight Hanford miniature swine using a preshaped catheter with an "S" curve in the SVC, and a major lobe in the atrium to enhance electrode contact with the atrial wall. The catheter was designed for pacing and sensing in the DDD mode. P wave amplitudes were also ascertained with two commercially available VDD leads and compared to the data from the experimental catheters. The preshaped catheter used two 6-mm2 platinum iridium atrial electrodes with a 7-mm separation. Both atrial electrodes are on the same side of the catheter, facing outward on the major atrial lobe formed in the catheter. The P wave amplitudes were tested only in the differential bipolar configuration. For the eight preshaped catheters, the mean was 6.6 +/- 3.8 mV while for the conventional leads it was 2.9 +/- 1.6 mV. The mean atrial stimulation thresholds ranged from 1.1 +/- 0.2 V to 2.3 +/- 1.2 V, with still lower thresholds of 0.9-1.3 V when using the parallel unipolar atrial electrode configuration, in which both parts of the bipolar atrial electrode are configured as a unipolar electrode. The data suggest that bipolar simulation may be effective if sequential reverse polarity pulses are used to achieve cathodal stimulation from each electrode of the bipolar pair, on a beat-to-beat basis.


Asunto(s)
Marcapaso Artificial , Animales , Catéteres de Permanencia , Electrodos , Diseño de Equipo , Porcinos , Porcinos Enanos
20.
Ann Surg ; 223(6): 709-16; discussion 716-7, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8645044

RESUMEN

OBJECTIVE: This study was done to determine the long-term outcome of breast conservation therapy (BCT) for patients with early-stage breast cancer during a period of treatment evolution at a single institution. SUMMARY BACKGROUND DATA: Breast cancer treatment has evolved from extensive surgical extirpation of the breast to treatment options that conserve the breast. Prospective and retrospective studies have confirmed the efficacy of BCT and justify its use for many patients with early breast cancer, but there is no universally accepted consensus as to who benefits from more aggressive application of surgery or radiotherapy in BCT. Prognostic variables for breast cancer and information on factors that contribute to local recurrence help predict BCT results. Continued analysis of BCT still is necessary to improve patient outcome. METHODS: Eighty-five patients treated with BCT (lumpectomy with adjuvant radiation therapy) at the Medical College of Virginia from 1980 to 1990 were identified. Clinicopathologic parameters and treatment details were analyzed for relationship to development of local recurrence, distant metastasis, and survival. Fisher's exact test was used for comparisons. Actuarial survival curves were plotted. The earlier treatment period (1980-1985) was compared with the later treatment period (1985-1990). RESULTS: Median follow-up was 5 years. Actuarial overall survival was 83% at 5 years (69% at 10 years), and 5-year distant metastasis-free survival was 79%. The 5-year actuarial local recurrence rate was 6.6% (crude rate 10.6%, 9/85). Young patients (age < 40 years) were found to be at increased risk for local recurrence (24% < 40 years vs. 6% > or = 40 years, p < 0.05). Tumor margins < or = 3 mm were more frequently found, and lumpectomy site radiation boost was used increasingly from 1986 to 1990. Almost half of all local recurrences occurred after 5 years. CONCLUSIONS: Survival and local recurrence rates were comparable to other series. Young patients were found to be at increased risk for local recurrence. Negative microscopic margins, even when close, can provide low local recurrence rates when adjuvant radiation therapy is administered.


Asunto(s)
Neoplasias de la Mama/cirugía , Mastectomía Segmentaria , Adulto , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/radioterapia , Femenino , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Pronóstico , Radioterapia Adyuvante , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del Tratamiento
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