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1.
Br J Anaesth ; 122(6): 751-759, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30916034

RESUMEN

BACKGROUND: Gestational changes in coagulation factor concentrations include elevations in fibrinogen, Factor VIII, and von Willebrand factor (vWF). We hypothesised that blood samples from term pregnant (TP) subjects are less prone to coagulation disturbances from haemodilution compared with those from non-pregnant (NP) females. METHODS: Blood samples were collected from 15 NP and 15 TP subjects. In vitro haemodilution with normal saline was assessed by modified Clauss fibrinogen assay, factor activity, flow-chamber assay, and thromboelastometry. The impact of human fibrinogen concentrate (hFC), cryoprecipitate, and vWF/Factor VIII (FVIII) concentrate replacement in diluted TP and NP blood was compared. Thrombin generation and activated protein C sensitivity were assessed. RESULTS: TP blood contained twice the concentrations of fibrinogen, FVIII, and vWF relative to NP blood (P<0.0001). Platelet thrombus formation (PTF) under flow was reduced by 99.2% and 69.2% in diluted NP and TP blood, respectively. Platelet thrombus formation was partially restored by adding vWF/FVIII, but not hFC or cryoprecipitate. Fibrin clot firmness approached the threshold of 10 mm in diluted NP blood, and clot firmness was effectively restored by hFC, but not by vWF/FVIII. In the presence of thrombomodulin, peak thrombin generation was decreased by 86.7% in NP plasma, but by 31.8% in TP plasma (P<0.0001 vs NP plasma), indicating reduced activated protein C sensitivity in TP plasma. Both elevated FVIII and haemodilution contributed to activated protein C insensitivity. CONCLUSIONS: Our in vitro model showed relative resistance of TP blood to dilutional coagulation changes with respect to platelet adhesion, fibrin polymerisation, and thrombin generation. Careful therapeutic monitoring for different pro-haemostatic agents in pregnant women is warranted.


Asunto(s)
Trastornos de la Coagulación Sanguínea/sangre , Factores de Coagulación Sanguínea/análisis , Hemodilución/efectos adversos , Complicaciones Hematológicas del Embarazo/sangre , Adulto , Trastornos de la Coagulación Sanguínea/etiología , Recolección de Muestras de Sangre/métodos , Monitoreo de Drogas/métodos , Factor VIII/análisis , Femenino , Fibrinógeno/análisis , Humanos , Embarazo , Complicaciones Hematológicas del Embarazo/etiología , Proteína C/análisis , Tromboelastografía/métodos , Trombina/biosíntesis , Adulto Joven , Factor de von Willebrand/análisis
2.
Phys Rev Lett ; 108(2): 022502, 2012 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-22324675

RESUMEN

Results of a new series of experiments on the study of production cross sections and decay properties of the isotopes of element 115 in the reaction (243)Am+(48)Ca are presented. Twenty-one new decay chains originating from (288)115 were established as the product of the 3n-evaporation channel by measuring the excitation function at three excitation energies of the compound nucleus (291)115. The decay properties of all newly observed nuclei are in full agreement with those we measured in 2003. At the lowest excitation energy E*=33 MeV, for the first time we registered the product of the 2n-evaporation channel, (289)115, which was also observed previously in the reaction (249)Bk+(48)Ca as the daughter nucleus of the decay of (293)117. The maximum cross section for the production of (288)115 is found to be 8.5 pb at E*≈36 MeV.

3.
Phys Rev Lett ; 109(16): 162501, 2012 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-23215070

RESUMEN

Two years after the discovery of element 117, we undertook a second campaign using the (249)Bk+(48)Ca reaction for further investigations of the production and decay properties of the isotopes of element 117 on a larger number of events. The experiments were started in the end of April 2012 and are still under way. This Letter presents the results obtained in 1200 hours of an experimental run with the beam dose of (48)Ca of about 1.5×10(19) particles. The (249)Bk target was irradiated at two energies of (48)Ca that correspond to the maximum probability of the reaction channels with evaporation of three and four neutrons from the excited (297)117. In this experiment, two decay chains of (294)117 (3n) and five decay chains of (293)117 (4n) were detected. In the course of the long-term work, (249)Cf-the product of decay of (249)Bk (330 d)-is being accumulated in the target. Consequently, in the present experiment, we also detected a single decay of the known isotope (294)118 that was produced during 2002-2005 in the reaction (249)Cf((48)Ca,3n)(294)118. The obtained results are compared with the data from previous experiments. The experiments are carried out in the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, using the heavy-ion cyclotron U400.

4.
Phys Rev Lett ; 104(14): 142502, 2010 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-20481935

RESUMEN

The discovery of a new chemical element with atomic number Z=117 is reported. The isotopes (293)117 and (294)117 were produced in fusion reactions between (48)Ca and (249)Bk. Decay chains involving 11 new nuclei were identified by means of the Dubna gas-filled recoil separator. The measured decay properties show a strong rise of stability for heavier isotopes with Z > or = 111, validating the concept of the long sought island of enhanced stability for superheavy nuclei.

5.
Vet Pathol ; 47(6): 1090-4, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20634406

RESUMEN

Multicentric cutaneous neuroendocrine (Merkel cell) carcinoma was diagnosed in a 5-year-old castrated male Keeshond dog with multiple firm nodular cutaneous masses. The neoplastic tissue locally effaced the periadnexal and deep dermis and consisted of densely cellular confluent clusters of round to polygonal cells supported by a delicate fibrovascular stroma. The cells were moderately immunoreactive with chromogranin A, synaptophysin, and cytokeratin. Ultrastructurally, the cells had characteristic membrane-bound dense-core neuroendocrine granules approximately 120 nm in diameter and randomly dispersed throughout the cytoplasm. Effacement of dermal structures and multicentric distribution suggested low-grade malignant phenotype. These findings contrast with the typical benign behavior of canine cutaneous neuroendocrine tumors.


Asunto(s)
Carcinoma de Células de Merkel/veterinaria , Enfermedades de los Perros/patología , Neoplasias Cutáneas/veterinaria , Animales , Carcinoma de Células de Merkel/patología , Carcinoma de Células de Merkel/ultraestructura , Cromogranina A/metabolismo , Enfermedades de los Perros/metabolismo , Perros , Resultado Fatal , Queratinas/metabolismo , Masculino , Piel/patología , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/ultraestructura , Sinaptofisina/metabolismo
6.
Science ; 245(4920): 847-50, 1989 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-17773362

RESUMEN

Since 1962 the crown-of-thorns starfish, Acanthaster planci, has caused the devastation of living coral in large tracts of the Great Barrier Reef, Australia. Some authorities view this as a modern phenomenon, resulting from ecological disturbance caused by man. Evidence from skeletal remains in sediment suggests that large A. planci populations have been part of the Great Barrier Reef ecosystem for at least 8000 years. Coral predation by A. planci is likely to have influenced the morphological fabric of the Great Barrier Reef in its post-glacial development and may also have influenced species richness of the reef biota.

7.
Science ; 255(5049): 1264-6, 1992 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-1546329

RESUMEN

Peptides extracted from HLA-A2.1 class I major histocompatibility complex (MHC) molecules expressed on the antigen processing mutant CEMx721.174.T2 were characterized by electrospray ionization-tandem mass spectrometry. Only seven dominant peptides were found, in contrast to over 200 associated with HLA-A2.1 on normal cells. These peptides were derived from the signal peptide domains of normal cellular proteins, were usually larger than nine residues, and were also associated with HLA-A2.1 in normal cells. These results suggest that proteolysis of signal peptide domains in the endoplasmic reticulum is a second mechanism for processing and presentation of peptides for association with class I molecules.


Asunto(s)
Células Presentadoras de Antígenos/inmunología , Antígenos/metabolismo , Antígeno HLA-A2/metabolismo , Péptidos/metabolismo , Secuencia de Aminoácidos , Antígenos/química , Antígenos/inmunología , Línea Celular , Cromatografía Líquida de Alta Presión , Antígeno HLA-A2/química , Humanos , Espectrometría de Masas , Datos de Secuencia Molecular , Mutación , Péptidos/química , Péptidos/inmunología , Señales de Clasificación de Proteína/química , Linfocitos T/inmunología
8.
Science ; 264(5159): 716-9, 1994 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-7513441

RESUMEN

Of several thousand peptides presented by the major histocompatibility molecule HLA-A2.1, at least nine are recognized by melanoma-specific cytotoxic T lymphocytes (CTLs). Tandem mass spectrometry was used to identify and to sequence one of these peptide epitopes. Melanoma-specific CTLs had an exceptionally high affinity for this nine-residue peptide, which reconstituted an epitope for CTL lines from each of five different melanoma patients tested. Recognition by multiple CTL lines suggests that this may be a promising candidate for use in peptide-based melanoma vaccines.


Asunto(s)
Antígenos de Neoplasias/inmunología , Melanoma/inmunología , Oligopéptidos/inmunología , Linfocitos T Citotóxicos/inmunología , Secuencia de Aminoácidos , Cromatografía Líquida de Alta Presión , Epítopos/inmunología , Antígeno HLA-A2/inmunología , Humanos , Espectrometría de Masas , Datos de Secuencia Molecular , Células Tumorales Cultivadas
9.
Science ; 255(5049): 1261-3, 1992 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-1546328

RESUMEN

Antigens recognized by T cells are expressed as peptides bound to major histocompatibility complex (MHC) molecules. Microcapillary high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry was used to fractionate and sequence subpicomolar amounts of peptides isolated from the MHC molecule HLA-A2.1. Of 200 different species quantitated, eight were sequenced and four were found in cellular proteins. All were nine residues long and shared a distinct structural motif. The sensitivity and speed of this approach should enhance the analysis of peptides from small quantities of virally infected and transformed cells as well as those associated with autoimmune disease states.


Asunto(s)
Antígenos/metabolismo , Antígeno HLA-A2/metabolismo , Espectrometría de Masas , Péptidos/metabolismo , Secuencia de Aminoácidos , Antígenos/química , Antígenos/inmunología , Línea Celular , Cromatografía Líquida de Alta Presión , Humanos , Técnicas de Inmunoadsorción , Datos de Secuencia Molecular , Péptidos/química , Péptidos/inmunología , Linfocitos T/inmunología
10.
Lancet ; 366(9489): 914-20, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16154018

RESUMEN

BACKGROUND: The long-term outcome of an interventional strategy in patients with non-ST-elevation acute coronary syndrome is unknown. We tested whether an interventional strategy (routine angiography followed by revascularisation) was better than a conservative strategy (ischaemia-driven or symptom-driven angiography) over 5 years' follow-up. METHODS: In a multicentre randomised trial, 1810 patients (from 45 hospitals in England and Scotland, UK) with non-ST-elevation acute coronary syndrome were randomly assigned to receive an early intervention (n=895) or a conservative strategy (n=915) within 48 h of the index episode of cardiac pain. In each group, the aim was to provide the best medical treatment, and also to undertake coronary arteriography within 72 h in the interventional strategy with subsequent management guided by the angiographic findings. Analysis was by intention to treat and the primary outcome (composite of death or non-fatal myocardial infarction) had masked independent adjudication. RITA 3 has been assigned the International Standard Randomised Control Trial Number ISRCTN07752711. FINDINGS: At 1-year follow-up, rates of death or non-fatal myocardial infarction were similar. However, at a median of 5 years' follow-up (IQR 4.6-5.0), 142 (16.6%) patients with intervention treatment and 178 (20.0%) with conservative treatment died or had non-fatal myocardial infarction (odds ratio 0.78, 95% CI 0.61-0.99, p=0.044), with a similar benefit for cardiovascular death or myocardial infarction (0.74, 0.56-0.97, p=0.030). 234 (102 [12%] intervention, 132 [15%] conservative) patients died during follow-up (0.76, 0.58-1.00, p=0.054). The benefits of an intervention strategy were mainly seen in patients at high risk of death or myocardial infarction (p=0.004), and for the highest risk group, the odds ratio of death or non-fatal myocardial infarction was 0.44 (0.25-0.76). INTERPRETATION: In patients with non-ST-elevation acute coronary syndrome, a routine invasive strategy leads to long-term reduction in risk of death or non-fatal myocardial infarction, and this benefit is mainly in high-risk patients. The findings provide support for national and international guidelines in the need for more robust risk stratification in acute coronary syndrome.


Asunto(s)
Angina Inestable/terapia , Electrocardiografía , Infarto del Miocardio/terapia , Angina Inestable/diagnóstico , Causas de Muerte , Angiografía Coronaria , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/mortalidad , Revascularización Miocárdica
11.
J Natl Cancer Inst ; 77(3): 783-92, 1986 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-3462415

RESUMEN

Six canine mammary tumor cell lines (5 epithelial, 1 myoepithelial) were established from dogs with spontaneous mammary carcinomas. The cells were characterized for features of morphology and growth patterns on plastic, ultrastructure, cloning efficiency in soft agar, tumorigenicity in athymic nude mice, and hormonal receptor status. Biologic properties of the cell lines were distinct and preserved during long-term culture in vitro. All cell lines were clonogenic, 5 of 6 were tumorigenic, and 3 of 5 were receptor positive for estrogen and/or progesterone.


Asunto(s)
Enfermedades de los Perros/patología , Glándulas Mamarias Animales , Neoplasias/veterinaria , Animales , Línea Celular , Medios de Cultivo , Enfermedades de los Perros/metabolismo , Perros , Femenino , Ratones , Ratones Desnudos , Neoplasias/patología , Neoplasias/ultraestructura , Receptores de Estrógenos/análisis , Receptores de Progesterona/análisis
12.
Cancer Res ; 56(16): 3763-70, 1996 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-8706022

RESUMEN

We have achieved stable high-level expression of a human tumor antigen, epithelial cell mucin (MUC-1), on human dendritic cells (DCs) by retroviral transduction of CD34+ progenitor cells and their subsequent cytokine-induced differentiation into DCs. The process of retroviral transduction did not alter the growth or differentiation of DCs from CD34+ progenitor cells. Immunofluorescence and electron microscopy studies revealed that the expression of mucin was limited to the body of the DCs and was excluded from the cytoplasmic veils of the DCs. Furthermore, the expression of mucin on DCs was similar, if not identical, to the nonpolarized expression of mucin found on carcinoma cells. In functional studies, the MUC-1(+)-transduced DCs were potent stimulators of allogeneic CD4+ T cells and, in fact, were superior to MUC-1- DCs. Thus, MUC-1+ DCs are expected to be a valuable tool in the immunotherapeutic treatment of patients with tumors that express MUC-1.


Asunto(s)
Antígenos de Neoplasias/biosíntesis , Células Dendríticas/metabolismo , Ingeniería Genética , Mucina-1/biosíntesis , Antígenos CD34/análisis , Células Madre Hematopoyéticas/citología , Humanos , Inmunoterapia , Activación de Linfocitos , Linfocitos T/inmunología
13.
J Am Coll Cardiol ; 35(4): 907-14, 2000 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-10732887

RESUMEN

OBJECTIVES: We sought to evaluate the impact of percutaneous transluminal coronary angioplasty (PTCA) and medical treatment on self-perceived quality of life among patients with angina. BACKGROUND: The second Randomized Intervention Treatment of Angina trial (RITA-2) implemented initial policies of PTCA or continued medical treatment in patients with angina, allowing assessment of long-term health consequences. METHODS: A total of 1,018 patients were randomly assigned (504 to PTCA and 514 to medical treatment). The short form 36 (SF-36) self-administered quality-of-life questionnaire was completed at randomization and three months, one year and three years later. To date, 98% of patients reached one year and 67% reached three years. RESULTS: The PTCA group had significantly greater improvements in physical functioning, vitality and general health at both three months and one year, but not at three years. These quality-of-life scores were strongly related to breathlessness, angina grade and treadmill exercise time both at baseline and at one year. The treatment differences in quality of life are explained by the PTCA group's improvements in breathlessness, angina and exercise time. The attenuation of treatment difference at three years is partly attributed to 27% of medically treated patients receiving nonrandomized interventions in the interim. For both groups, there were also improvements in ratings of physical role functioning, emotional role functioning, social functioning, pain and mental health, but for these the superiority of PTCA over medical treatment was less pronounced. After one year, 33% and 22% of the PTCA and medical groups, respectively, rated their health much better. CONCLUSIONS: Coronary angioplasty substantially improves patient-perceived quality of life, especially physical functioning and vitality, as compared with continued medical treatment. These differences are attributed to alleviation of cardiac symptoms (specifically, breathlessness and angina), but must be balanced against the small procedure-related risks of PTCA.


Asunto(s)
Angina de Pecho/terapia , Angioplastia Coronaria con Balón , Enfermedad Coronaria/terapia , Calidad de Vida , Actividades Cotidianas/clasificación , Antagonistas Adrenérgicos beta/uso terapéutico , Adulto , Anciano , Angina de Pecho/diagnóstico , Angina de Pecho/psicología , Bloqueadores de los Canales de Calcio/uso terapéutico , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nitratos/uso terapéutico , Resultado del Tratamiento
14.
Endocrinology ; 139(4): 2048-57, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9528993

RESUMEN

Estrogen responsiveness of bone is a fundamental regulatory mechanism operative in skeletal homeostasis. We examined the expression of estrogen receptor-alpha (ER) messenger RNA (mRNA) in cultured rat calvarial-derived osteoblasts during progressive development of the osteoblast phenotype. Levels of ER message were compared with the expression of traditional osteoblastic markers that have been mapped throughout the differentiation process of these cells. ER transcripts, measured using semiquantitative RT-PCR analysis, were expressed at low levels in early stage proliferating osteoblasts and increased at confluence upon initial expression of bone cell phenotypic genes. A 23-fold up-regulation of ER mRNA expression coincided with the initiation of alkaline phosphatase activity (day 8). ER mRNA levels progressively increased 70-fold, reaching a maximum level on days 22-25 in fully differentiated osteoblasts when osteocalcin expression peaked, but declined precipitously by day 32 in osteocytic cells. Analysis of RNA isolated directly from rat calvaria confirmed these in vitro results and demonstrated that ER message levels become more abundant postnatally as bone becomes more mineralized. We also examined the responsiveness of osteoblasts to 17beta-estradiol (17beta-E2) at two periods of maturation: the nodule-forming stage (day 14) and the late mineralization stage (day 30). Estradiol suppressed the levels of alkaline phosphatase, osteocalcin, osteonectin, and ER mRNAs on day 14, but up-regulated these messages on day 30. In contrast, 17beta-E2 treatment regulated the steady state levels of transforming growth factor-beta1 and type I procollagen mRNAs only in the late mineralization stage, whereas histone H4 message was unaffected by the steroid at either stage of differentiation. Thus, the observed developmental expression of ER mRNA correlates with progressive osteoblast differentiation and may be a contributing factor to differential regulation of bone cell gene expression by 17beta-E2.


Asunto(s)
Diferenciación Celular , Regulación del Desarrollo de la Expresión Génica , Osteoblastos/citología , Receptores de Estrógenos/genética , Animales , Huesos/embriología , Calcificación Fisiológica , Células Cultivadas , Colágeno/genética , Estradiol/farmacología , Femenino , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Masculino , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Ratas , Factores de Tiempo , Factor de Crecimiento Transformador beta/genética , Regulación hacia Arriba
15.
Free Radic Biol Med ; 6(5): 505-12, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2744583

RESUMEN

Vitamin E and selenium play essential roles in preventing in vivo lipid peroxidation and free radical damage. Hyperbaric oxygen (HBO) treatment adversely affected the electroretinograms (ERGs) of rats fed a diet deficient in both vitamin E and selenium (the basal or B diet) or a diet deficient in vitamin E alone (B + Se diet). After 4 weeks of HBO treatment (3.0 ATA or 100% oxygen, 1.5 hours per day, 5 day/week) rats fed the B diet deficient in vitamin E and selenium for 6 weeks showed decreased (p less than 0.05) a-wave amplitudes, 85 +/- 9 microvolts (microV), n = 11, compared with a-waves recorded (150 +/- 10 microV, n = 21) for age matched rats fed an identical diet for 6 weeks but not treated with HBO. After 15 weeks of HBO treatment, rats fed the B + Se diet deficient in vitamin E alone showed decreased (p less than 0.01) a-wave (61 +/- 9 microV, n = 4) and b-wave (253 +/- 23 microV, n = 4) amplitudes compared with a-wave (115 +/- 7 microV, n = 4) and b-wave amplitudes (450 +/- 35 microV, n = 4) for age matched rats fed the same diet but not treated with HBO. Decreased a- or b-wave amplitudes provide evidence of retinal damage. Rats fed a diet supplemented with vitamin E and selenium or vitamin E alone showed no decreases in either a- or b-wave amplitudes after 15 weeks of HBO treatment.


Asunto(s)
Antioxidantes/farmacología , Oxigenoterapia Hiperbárica , Enfermedades de la Retina/inducido químicamente , Animales , Peso Corporal/efectos de los fármacos , Dieta , Electrorretinografía , Glutatión Peroxidasa/metabolismo , Masculino , Ratas , Ratas Endogámicas F344 , Enfermedades de la Retina/fisiopatología , Selenio/metabolismo , Selenio/farmacología , Factores de Tiempo , Vitamina E/farmacología
16.
Am J Clin Nutr ; 73(4): 821-6, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11273859

RESUMEN

BACKGROUND: Early diagnostic efforts and advances in multidrug therapy have considerably prolonged the survival time of children infected perinatally with HIV. Despite these advances, few studies have addressed calcium status and bone growth in HIV-infected children. OBJECTIVE: Our objective was to examine the effect of HIV infection on calcium status and bone growth in children. DESIGN: We measured calcitropic hormones, urinary calcium excretion, bone mineral content, and body composition in 19 young girls aged 9.2 +/- 2.6 y (range: 5.9-15.2 y) who were infected perinatally with HIV. RESULTS: Serum concentrations of 1,25-dihydroxyvitamin D [1,25(OH)(2)D] and parathyroid hormone concentrations were elevated above normal ranges in 25% and 12% of these girls, respectively. Urinary calcium excretion normalized for creatinine excretion was also elevated (Ca/Cr >0.18) in 17% of these children despite suboptimal calcium intakes (679 +/- 437 mg/d). Total-body bone mineral content, measured with the use of dual-energy X-ray absorptiometry, averaged 845.1 +/- 279.0 g and was on average 2.7 z scores below age- and race-matched values reported in non-HIV-infected healthy girls. Significant positive correlations were found between an indirect marker of bone resorption in urine (N:-telopeptide) and 1,25(OH)2D (P < 0.02, r2 = 0.586, n = 9), and between serum N-telopeptide and total alkaline phosphatase (P < 0.001, r2 = 0.541, n = 17), suggesting that calcium insufficiency may be increasing bone resorption in this group. CONCLUSIONS: Young girls with HIV infection had low bone mass and evidence of calcium insufficiency. Nutritional counseling of children with HIV infection should emphasize adequate calcium intakes because of the importance of this age period in bone mineral acquisition.


Asunto(s)
Densidad Ósea/fisiología , Calcitriol/sangre , Calcio/análisis , Infecciones por VIH/complicaciones , Hormona Paratiroidea/sangre , Absorciometría de Fotón , Adolescente , Fenómenos Fisiológicos Nutricionales de los Adolescentes , Población Negra , Composición Corporal , Desarrollo Óseo , Resorción Ósea , Calcio/deficiencia , Niño , Fenómenos Fisiológicos Nutricionales Infantiles , Preescolar , Creatinina/orina , Femenino , Humanos , Recuerdo Mental , Atención Perinatal , Población Blanca
17.
Int J Radiat Oncol Biol Phys ; 17(6): 1341-6, 1989 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2599914

RESUMEN

Previous studies have shown implantable ferromagnetic thermoseeds to be a promising hyperthermia method. However, migration from the implant site and chemical toxicity caused by corrosion of the thermoseed alloy have proven to be potential hazards. These problems could be overcome by placing the thermoseeds into removable catheters similar to those used for afterloading interstitial brachytherapy. As an additional merit, the method would allow convenient combination of heat and radiation therapy. To test the clinical performance of this method, we compared temperature distributions and biologic effects in canine muscle and transmissible venereal tumors for bare thermoseeds and thermoseeds contained within catheters. We found no significant difference in the heating patterns and similar tissue changes when all implants were removed immediately after heating. More severe tissue changes were present around bare thermoseeds that were retained. This suggests that catheters provide a safe and reliable method for thermoseed hyperthermia which would allow convenient combination with interstitial radiation.


Asunto(s)
Compuestos Férricos , Hipertermia Inducida/instrumentación , Aleaciones/uso terapéutico , Animales , Catéteres de Permanencia , Cobre/uso terapéutico , Corrosión , Perros , Níquel/uso terapéutico , Tumores Venéreos Veterinarios/terapia
18.
Shock ; 13(4): 320-4, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10774622

RESUMEN

This study examines the early time course in core temperature change and oxygen consumption at 4 levels of hemorrhage. Chronically instrumented rats were acclimatized to a respirometry chamber for 30 min. The rats were briefly (10 min) removed from the chamber for a fixed volume hemorrhage of 0 mL/kg (sham), 8 mL/kg, 16 mL/kg, 24 mL/kg, or 32 mL/kg. Rats were then returned to the chamber, and oxygen consumption and body core temperature were monitored for the next 2 h. Oxygen consumption (control 1.26 mL O2/g/h) fell significantly 5 min after hemorrhage in all but the sham and 8 mL/kg hemorrhage groups, with the decrease proportional to the hemorrhage volume. The 32 mL/kg hemorrhage group showed the greatest decrease, to 0.47 mL O2/g/h. Body core temperature (control 37.5 degrees C) fell more gradually, declining to 35.6 degrees C 110 min after the 24 mL/kg hemorrhage, and to 33.2 degrees C at 6 h after the 32 mL/kg hemorrhage. In the 16 mL/kg hemorrhage group, oxygen consumption fell significantly by 5 min after hemorrhage, but a drop in body temperature was not seen until 25 min after hemorrhage. The data from this study indicate that the drop in core temperature does not cause the observed decrease in oxygen consumption. In fact, the timing and magnitude of the drop in oxygen consumption indicate that the reduced metabolic rate may mediate the hemorrhage-induced drop in body core temperature in conscious rats.


Asunto(s)
Temperatura Corporal , Hemorragia/fisiopatología , Consumo de Oxígeno , Animales , Calorimetría , Masculino , Ratas , Ratas Sprague-Dawley , Valores de Referencia , Factores de Tiempo
19.
Arch Pediatr Adolesc Med ; 149(5): 497-502, 1995 May.
Artículo en Inglés | MEDLINE | ID: mdl-7735401

RESUMEN

OBJECTIVES: To describe and to evaluate the longitudinal growth of children born to mothers with human immunodeficiency virus (HIV) infection. DESIGN: Measurements of weight, length (measured in infants in a recumbent position) and height (measured in older children in an upright position), and head circumference were documented and evaluated longitudinally using generalized estimating equations in a group of children born to HIV-infected mothers. Children infected with HIV were compared with uninfected children and with National Center for Health Statistics standards. SETTING: Primary care clinic in an urban hospital devoted to the medical care of children born to HIV-infected mothers. PATIENTS: One hundred nine children born to HIV-infected mothers, 59 HIV-infected and 50 uninfected, between birth and 70 months of age. RESULTS: The mean birth weights of both groups were below the 50th percentile. While the mean weight-for-age curve of uninfected children attained the 50th percentile by age 24 months, the mean birth weight-for-age curve of HIV-infected children remained below the 50th percentile. Weight gain became significantly different between the two groups by age 36 months. The mean birth length-for-age curves of HIV-infected and uninfected children was also below the 50th percentile. The mean height-for-age curve of uninfected children attained the 50th percentile by age 40 months, while that of HIV-infected children remained well below the 50th percentile. Linear growth between HIV-infected and uninfected children diverged earlier than weight, becoming significantly different by age 15 months. CONCLUSIONS: Although children born to HIV-infected mothers are born with weight and length below the 50th percentile, uninfected children catch up, while HIV-infected children remain below the 50th percentile and experience an earlier and more pronounced decrease in linear growth (height-for-age) than in weight-for-age.


Asunto(s)
Crecimiento/fisiología , Infecciones por VIH/fisiopatología , Madres , Estatura/fisiología , Peso Corporal/fisiología , Preescolar , Femenino , Humanos , Lactante , Estudios Longitudinales , Masculino
20.
J Appl Physiol (1985) ; 90(5): 1887-99, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11299283

RESUMEN

We previously reported (J Appl Physiol 89: 807-822, 2000) that < or =10 min of hyperbaric oxygen (HBO(2); < or = 2,468 Torr) stimulates solitary complex neurons. To better define the hyperoxic stimulus, we measured PO(2) in the solitary complex of 300-microm-thick rat medullary slices, using polarographic carbon fiber microelectrodes, during perfusion with media having PO(2) values ranging from 156 to 2,468 Torr. Under control conditions, slices equilibrated with 95% O(2) at barometric pressure of 1 atmospheres absolute had minimum PO(2) values at their centers (291 +/- 20 Torr) that were approximately 10-fold greater than PO(2) values measured in the intact central nervous system (10-34 Torr). During HBO(2), PO(2) increased at the center of the slice from 616 +/- 16 to 1,517 +/- 15 Torr. Tissue oxygen consumption tended to decrease at medium PO(2) or = 1,675 Torr to levels not different from values measured at PO(2) found in all media in metabolically poisoned slices (2-deoxy-D-glucose and antimycin A). We conclude that control medium used in most brain slice studies is hyperoxic at normobaric pressure. During HBO(2), slice PO(2) increases to levels that appear to reduce metabolism.


Asunto(s)
Tronco Encefálico/fisiología , Consumo de Oxígeno , Oxígeno/análisis , Animales , Antimicina A/farmacología , Tronco Encefálico/efectos de los fármacos , Calibración , Desoxiglucosa/farmacología , Electroquímica/métodos , Oxigenoterapia Hiperbárica , Hiperoxia , Técnicas In Vitro , Presión Parcial , Ratas , Ratas Sprague-Dawley
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