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1.
Pharmacogenomics J ; 18(2): 347-350, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-28696416

RESUMEN

Despite the recognition that drug-drug interactions contribute substantially to preventable health-care costs, the prevalence of such interactions related to the cytochrome P450 system in clinical practice remains poorly characterized. This study drew retrospective hospital discharge cohorts from a large health claims data set and a large health system data set. For every hospital discharge, frequency of co-occurrence of substrates and inducers or inhibitors at cytochrome P450 2D6, 2C19, 3A4 and 1A2 were determined. A total of 124 520 individuals in the state of Massachusetts (health claims cohort) and 77 026 individuals in two large academic medical centers (electronic health record (EHR) cohort) were examined. In the claims cohort, 35 157 (28.2%) exhibited at least one CYP450 drug-drug interaction at hospital discharge, whereas in the EHR cohort, 36 750 (47.7%) had at least one interaction. The most commonly affected CYP450 systems were 2C19 and 2D6, with putative interactions observed in at least 10% of individuals at discharge in each cohort. Odds of hospital readmission within 90 days among those discharged with at least one interaction were 10-16% greater, with mean health-care cost $574/month greater over the subsequent year, after adjusting for age, sex, insurance type, total number of medications prescribed, Charlson comorbidity score and presence or absence of a psychiatric diagnosis. These two distinct clinical data types show that CYP450 drug-drug interactions are prevalent and associated with greater probability of early hospital readmission and greater health-care cost, despite the widespread availability and application of drug-drug interaction checking software.


Asunto(s)
Inductores de las Enzimas del Citocromo P-450/metabolismo , Inhibidores Enzimáticos del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Interacciones Farmacológicas/fisiología , Alta del Paciente/tendencias , Anciano , Estudios de Cohortes , Inductores de las Enzimas del Citocromo P-450/efectos adversos , Inhibidores Enzimáticos del Citocromo P-450/efectos adversos , Sistema Enzimático del Citocromo P-450/genética , Femenino , Estudios de Seguimiento , Humanos , Formulario de Reclamación de Seguro/tendencias , Masculino , Massachusetts/epidemiología , Persona de Mediana Edad , Prevalencia
3.
Pharmacogenomics J ; 17(4): 382-385, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-27168099

RESUMEN

The cytochrome P450 (CYP450) system of drug-metabolizing enzymes may contribute to individual variation in drug response. We examined prevalence of CYP450 substrates at hospital discharge for patients in two cohorts: insurance claims of Massachusetts residents and the medical records of two academic medical centers. The claims cohort included 47 473 individuals (38.2%) treated with at least one CYP450 2D6, 2C19, 3A4 or 1A2 substrate. The electronic medical records cohort included 45 905 individuals (57.4%) treated with at least one substrate. In adjusted models, substrates of CYP450 2D6 and 2C19 were associated with greater risk for 90-day readmission in both cohorts (odds ratios of 1.104 and 1.128 (P<0.001), respectively). Presence of any CYP450 substrate was associated with increased monthly medical costs (+$397, P<0.003). These analyses of more than 300 000 admissions using two different cohorts and data types indicate that CYP450 substrates are associated with greater readmission rates and greater health-care cost.


Asunto(s)
Sistema Enzimático del Citocromo P-450/metabolismo , Femenino , Humanos , Masculino , Massachusetts , Persona de Mediana Edad , Oxidación-Reducción , Prevalencia
4.
Nat Commun ; 15(1): 5653, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38969628

RESUMEN

Rubble pile asteroids are widely understood to be composed of reaccumulated debris following a catastrophic collision between asteroids in the main asteroid belt, where each disruption can make a family of new asteroids. Near-Earth asteroids Ryugu and Bennu have been linked to collisional families in the main asteroid belt, but surface age analyses of each asteroid suggest these bodies are substantially younger than their putative families. Here we show, through a coupled collisional and dynamical evolution of members of these families, that neither asteroid was likely to have been created at the same time as the original family breakups, but rather are likely remnants of later disruptions of original family members, making them second, or later, generation remnants. Our model finds about 80% and 60% of asteroids currently being delivered to near-Earth orbits from the respective families of New Polana and Eulalia are second or later generation. These asteroids delivered today in the 0.5-1 km size range have median ages since their last disruption that are substantially younger than the family age, reconciling their measured crater retention ages with membership in these families.

5.
J Geophys Res Planets ; 126(2): e2020JE006624, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33777607

RESUMEN

We describe the capabilities, radiometric stability, and calibration of a custom vacuum environment chamber capable of simulating the near-surface conditions of airless bodies. Here we demonstrate the collection of spectral measurements of a suite of fine particulate asteroid analogs made using the Planetary Analogue Surface Chamber for Asteroid and Lunar Environments (PASCALE) under conditions like those found on Earth and on airless bodies. The sample suite includes anhydrous and hydrated physical mixtures, and chondritic meteorites (CM, CI, CV, CR, and L5) previously characterized under Earth- and asteroid-like conditions. And for the first time, we measure the terrestrial and extra-terrestrial mineral end members used in the olivine- and phyllosilicate-dominated physical mixtures under the same conditions as the mixtures and meteorites allowing us better understand how minerals combine spectrally when mixed intimately. Our measurements highlight the sensitivity of thermal infrared emissivity spectra to small amounts of low albedo materials and the composition of the sample materials. As the albedo of the sample decreases, we observe smaller differences between Earth- and asteroid-like spectra, which results from a reduced thermal gradient in the upper hundreds of microns in the sample. These spectral measurements can be compared to thermal infrared emissivity spectra of asteroid (101955) Bennu's surface in regions where similarly fine particulate materials may be observed to infer surface compositions.

6.
Science ; 370(6517)2020 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-33033155

RESUMEN

The composition of asteroids and their connection to meteorites provide insight into geologic processes that occurred in the early Solar System. We present spectra of the Nightingale crater region on near-Earth asteroid Bennu with a distinct infrared absorption around 3.4 micrometers. Corresponding images of boulders show centimeters-thick, roughly meter-long bright veins. We interpret the veins as being composed of carbonates, similar to those found in aqueously altered carbonaceous chondrite meteorites. If the veins on Bennu are carbonates, fluid flow and hydrothermal deposition on Bennu's parent body would have occurred on kilometer scales for thousands to millions of years. This suggests large-scale, open-system hydrothermal alteration of carbonaceous asteroids in the early Solar System.

7.
J Geophys Res Planets ; 125(3): e2019JE006296, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32714727

RESUMEN

Some years ago, the consensus was that asteroid (16) Psyche was almost entirely metal. New data on density, radar properties, and spectral signatures indicate that the asteroid is something perhaps even more enigmatic: a mixed metal and silicate world. Here we combine observations of Psyche with data from meteorites and models for planetesimal formation to produce the best current hypotheses for Psyche's properties and provenance. Psyche's bulk density appears to be between 3,400 and 4,100 kg m-3. Psyche is thus predicted to have between ~30 and ~60 vol% metal, with the remainder likely low-iron silicate rock and not more than ~20% porosity. Though their density is similar, mesosiderites are an unlikely analog to bulk Psyche because mesosiderites have far more iron-rich silicates than Psyche appears to have. CB chondrites match both Psyche's density and spectral properties, as can some pallasites, although typical pallasitic olivine contains too much iron to be consistent with the reflectance spectra. Final answers, as well as resolution of contradictions in the data set of Psyche physical properties, for example, the thermal inertia measurements, may not be resolved until the NASA Psyche mission arrives in orbit at the asteroid. Despite the range of compositions and formation processes for Psyche allowed by the current data, the science payload of the Psyche mission (magnetometers, multispectral imagers, neutron spectrometer, and a gamma-ray spectrometer) will produce data sets that distinguish among the models.

8.
Science ; 267(5206): 1981-4, 1995 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-7701319

RESUMEN

Isotopic signatures of nitrogen, argon, and xenon have been determined in separated millimeter-sized pockets of shock-melted glass in a recently identified lithology of the meteorite Zagami, a shergottite. The ratio of nitrogen-15 to nitrogen-14, which is at least 282 per mil larger than the terrestrial value, the ratio of xenon-129 to xenon-132 = 2.40, and the argon isotopic abundances match the signatures previously observed in the glassy lithology of the Antarctic shergottite EETA 79001. These results show that the signatures in EETA 79001 are not unique but characterize the trapped gas component in shock-melted glass of shergottites. The isotopic and elemental ratios of nitrogen, argon, and xenon closely resemble the Viking spacecraft data for the martian atmosphere and provide compelling evidence for a martian origin of the two shergottites and, by extension, of the meteorites in the shergottites-nakhlites-chassignites (SNC) group.


Asunto(s)
Argón/análisis , Marte , Nitrógeno/análisis , Sistema Solar , Xenón/análisis , Atmósfera , Medio Ambiente Extraterrestre , Vidrio
9.
Int J Pharm ; 572: 118807, 2019 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-31678526

RESUMEN

During lyophilisation cycle design, primary drying parameters (chamber pressure and shelf temperature) are adjusted to maximize the sublimation rate and prevent cake collapse, by maintaining the product continuously below its critical temperatures. The objective of this study was to employ mixture design of experiments to generate empirical models capable of predicting glass transition of the maximally freeze concentrated solution (Tg') and collapse temperature (Tc) of amorphous protein (BSA and IgG1) formulations. Additionally, the models developed aid the design of high concentration protein formulations with maximised critical temperatures to obtain shorter and more cost-effective lyophilisation cycles. Formulations contain sucrose as cryo/lyo-protectant and arginine/arginine-HCl as multifunctional excipient (e.g. solubility enhancer, viscosity and aggregation suppressor). The impact of formulation components at varied ratios on critical temperatures was evaluated; the amorphous excipients decrease critical temperatures, on the contrary, the protein increases critical temperatures. The robustness of the empirical models generated with BSA formulations was verified with BSA and IgG1 formulations. The models showed greater accuracy in predicting Tg' than the Fox-Flory equation. For the first time, empirical models are reported to predict both critical temperatures. Finally, unconventional collapse events observed for formulations with and without arginine/arginine-HCl at different protein concentrations are also discussed.


Asunto(s)
Liofilización , Inmunoglobulina G/química , Albúmina Sérica Bovina/química , Tecnología Farmacéutica/métodos , Temperatura , Arginina/química , Crioprotectores/química , Composición de Medicamentos , Excipientes/química , Presión , Agregado de Proteínas , Solubilidad , Sacarosa/química , Viscosidad , Vitrificación
10.
Nat Astron ; 3(4): 332-340, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31360777

RESUMEN

Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of meters observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu's spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth.

11.
Eur J Pharm Biopharm ; 131: 8-24, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30006246

RESUMEN

The study presented is a comprehensive overview of commercial parenteral protein formulations, approved by the European Medicines Agency (EMA), 1995-2018. The objective of this overview was to analyse current trends in the design of commercial parenteral protein products and thereby support formulation scientists in the design of new formulations. The main data source was the publicly available European Public Assessment Reports (EPARs) published by the EMA for each authorised product. An analysis of the percentage of formulations in a liquid and lyophilised form was conducted. In addition, the number of products containing individual excipients, classified into functional categories is provided. Finally, the overview includes comprehensive details of product compositions obtained from EMA, US Food and Drug Administration (FDA) and product Marketing Authorisation Holder. Data analysis highlighted trends in the number of products approved, and the higher percentage of liquid parenteral protein formulations (66%) compared to lyophilised formulations (34%). This overview identifies the most commonly incorporated excipients employed as buffering agents, stabilisers/bulking agents, surfactants, preservatives and tonicifiers, including their concentration ranges of use in both liquid and lyophilised formulation approaches. Finally, antibody-based formulations were a particular focus of this overview. The relationship between parenteral routes of administration and antibody concentrations in approved products was also investigated.


Asunto(s)
Composición de Medicamentos/métodos , Infusiones Parenterales , Proteínas/administración & dosificación , Aprobación de Drogas , Unión Europea , Excipientes , Humanos , Proteínas/química
12.
J Comp Pathol ; 162: 29-42, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30060840

RESUMEN

Endomyocarditis is a commonly detected post-mortem finding in domestic cats presenting for sudden onset cardiovascular death, yet the aetiology remains unresolved. Cats are documented reservoir hosts for Bartonella henselae, the infectious cause of cat scratch disease in man. Various Bartonella spp. have been associated with culture-negative endocarditis, myocarditis and sudden death in man and animals. We hypothesized that Bartonella spp. DNA could be amplified more often from the hearts of cats with feline endomyocarditis-left ventricular endocardial fibrosis (FEMC-LVEF) complex compared with cats with hypertrophic cardiomyopathy (HCM) or cats with grossly and microscopically unremarkable hearts (designated non-cardiac disease controls). Formalin-fixed and paraffin wax-embedded, cardiac tissues from 60 domestic and purebred cats aged 3 months to 18 years were examined, and histological features were recorded. Cardiac tissue sections were tested for Bartonella DNA using multiple 16-23S intergenic transcribed spacer region polymerase chain reaction (PCR) primer sets, including two Bartonella genera, a Bartonella koehlerae species-specific and a Bartonella vinsonii subsp. berkhoffii-specific assay, followed by DNA sequence confirmation of the species or genotype. Special precautions were taken to avoid DNA cross-contamination between tissues. Bartonella spp. DNA was amplified by PCR and sequenced from 18 of 36 cats (50%) with FEMC-LVEF and 1/12 (8.3%) cats with HCM. Bartonella spp. DNA was not amplified from any non-cardiac disease control hearts. Based on PCR/DNA sequencing, one Bartonella spp. was amplified from 10 cats, while the remaining eight were coinfected with more than one Bartonella spp. To our knowledge, this study represents the first documentation of B. vinsonii subsp. berkhoffii genotype I infection in cats (n = 11). Fluorescence in-situ hybridization testing facilitated visualization of Bartonella bacteria within the myocardium of four of seven PCR-positive FEMC-LVEF hearts. Collectively, these findings support the hypothesis that Bartonella spp. may play a primary role or act as a cofactor in the pathogenesis of FEMC-LVEF. Studies involving cats from other geographical regions and definitive demonstration of Bartonella spp. within regions of inflammation are needed to confirm an association between Bartonella spp. and FEMC-LVEF induced morbidity and mortality in cats.


Asunto(s)
Infecciones por Bartonella/veterinaria , Enfermedades de los Gatos/microbiología , Endocarditis Bacteriana/veterinaria , Miocarditis/veterinaria , Animales , Bartonella , Gatos , ADN Bacteriano/análisis
13.
Transl Psychiatry ; 7(9): e1238, 2017 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-28926002

RESUMEN

Major depressive disorder frequently co-occurs with medical disorders, raising the possibility of shared genetic liability. Recent identification of 15 novel genetic loci associated with depression allows direct investigation of this question. In cohorts of individuals participating in biobanks at two academic medical centers, we calculated polygenic loading for risk loci reported to be associated with depression. We then examined the association between such loading and 50 groups of clinical diagnoses, or topics, drawn from these patients' electronic health records, determined using a novel application of latent Dirichilet allocation. Three topics showed experiment-wide association with the depression liability score; these included diagnostic groups representing greater prevalence of mood and anxiety disorders, greater prevalence of cardiac ischemia, and a decreased prevalence of heart failure. The latter two associations persisted even among individuals with no mood disorder diagnosis. This application of a novel method for grouping related diagnoses in biobanks indicate shared genetic risk for depression and cardiac disease, with a pattern suggesting greater ischemic risk and diminished heart failure risk.


Asunto(s)
Trastornos de Ansiedad/genética , Trastorno Depresivo Mayor/genética , Predisposición Genética a la Enfermedad/genética , Insuficiencia Cardíaca/genética , Trastornos del Humor/genética , Herencia Multifactorial , Isquemia Miocárdica/genética , Adulto , Anciano , Anciano de 80 o más Años , Trastornos de Ansiedad/epidemiología , Trastorno Depresivo Mayor/epidemiología , Europa (Continente)/epidemiología , Femenino , Predisposición Genética a la Enfermedad/epidemiología , Insuficiencia Cardíaca/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Trastornos del Humor/epidemiología , Isquemia Miocárdica/epidemiología
14.
Int Angiol ; 25(3): 304-9, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16878081

RESUMEN

AIM: In the past decade we experienced a steady growth in the number of young smokers with severe premature lower extremity atherosclerosis (PLEA) and high frequency of familial cardiovascular disease (Fam CVD). The widely used Framingham risk score does not include Fam CVD among predictors of incident CVD. METHODS: We studied 370 patients younger than 55 with severe PLEA (45% females, 96% smokers) treated between 1998 and 2004. Overall, 312 (85%) patients reported a positive history of Fam CVD; 217 (59%) had family history of premature CVD (FamP-CVD), and 29% had history of early malignancies in family members <60 years (Fam Mal <60). RESULTS: Patients with FamP-CVD compared to those without FamP-CVD had similar prevalence of traditional risk factors, and concentrations of metabolic and inflammatory parameters, however had greater prevalence of clinical coronary artery disease (P=0.03), cerebrovascular disease (P=or<0.01) or both (P<0.01). Patients with both FamP-CVD and Fam Mal <60 (n=58) when compared to those with neither (n=92), had greater frequency of dyslipidemia (P=0.02) and coronary revascularizations (P=0.02). Patients with Fam P-CVD had 3-fold higher odds of prevalent CVD compared to those without Fam P-CVD. This association was independent of demographic and cardiovascular risks. CONCLUSIONS: In patients with PLEA, familial premature CVD may predict early clinical manifestations of systemic atherosclerosis, independently of traditional risk factors. Patients with family history of early malignancies had similar clinical characteristics, including prevalence of CVD.


Asunto(s)
Aterosclerosis/complicaciones , Aterosclerosis/patología , Extremidad Inferior/irrigación sanguínea , Neoplasias/complicaciones , Neoplasias/patología , Adulto , Análisis de Varianza , Aterosclerosis/epidemiología , Enfermedades Cardiovasculares/complicaciones , Enfermedades Cardiovasculares/patología , Dislipidemias/complicaciones , Dislipidemias/patología , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/epidemiología , North Carolina/epidemiología , Prevalencia , Proyectos de Investigación , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo
15.
Transl Psychiatry ; 6(10): e921, 2016 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-27754482

RESUMEN

The ability to predict psychiatric readmission would facilitate the development of interventions to reduce this risk, a major driver of psychiatric health-care costs. The symptoms or characteristics of illness course necessary to develop reliable predictors are not available in coded billing data, but may be present in narrative electronic health record (EHR) discharge summaries. We identified a cohort of individuals admitted to a psychiatric inpatient unit between 1994 and 2012 with a principal diagnosis of major depressive disorder, and extracted inpatient psychiatric discharge narrative notes. Using these data, we trained a 75-topic Latent Dirichlet Allocation (LDA) model, a form of natural language processing, which identifies groups of words associated with topics discussed in a document collection. The cohort was randomly split to derive a training (70%) and testing (30%) data set, and we trained separate support vector machine models for baseline clinical features alone, baseline features plus common individual words and the above plus topics identified from the 75-topic LDA model. Of 4687 patients with inpatient discharge summaries, 470 were readmitted within 30 days. The 75-topic LDA model included topics linked to psychiatric symptoms (suicide, severe depression, anxiety, trauma, eating/weight and panic) and major depressive disorder comorbidities (infection, postpartum, brain tumor, diarrhea and pulmonary disease). By including LDA topics, prediction of readmission, as measured by area under receiver-operating characteristic curves in the testing data set, was improved from baseline (area under the curve 0.618) to baseline+1000 words (0.682) to baseline+75 topics (0.784). Inclusion of topics derived from narrative notes allows more accurate discrimination of individuals at high risk for psychiatric readmission in this cohort. Topic modeling and related approaches offer the potential to improve prediction using EHRs, if generalizability can be established in other clinical cohorts.


Asunto(s)
Trastorno Depresivo Mayor/diagnóstico , Trastorno Depresivo Mayor/terapia , Registros Electrónicos de Salud , Narración , Procesamiento de Lenguaje Natural , Resumen del Alta del Paciente , Readmisión del Paciente , Adulto , Anciano , Estudios de Cohortes , Trastorno Depresivo Mayor/psicología , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Massachusetts , Persona de Mediana Edad , Modelos Estadísticos , Medición de Riesgo , Factores de Tiempo
16.
Biomaterials ; 8(5): 329-40, 1987 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-3676419

RESUMEN

The bulk and surface properties and blood compatibility of a series of polyurethanes based on methylene bis(p-phenyl isocyanate), 1,4-butanediol, and poly(tetramethylene oxide) of molecular weight 1000 were studied. The hard-to-soft segment ratio of these multiphase polymers was varied, and the effect of substituting a poly(dimethylsiloxane)-containing polyol in place of 5% of the polyether soft segment was studied. Bulk properties such as tensile strength and modulus increased with hard segment content, as did surface wettability and ESCA nitrogen content. However, blood compatibility measured by a canine ex vivo blood-contacting experiment was not found to vary with hard/soft segment ratio. The addition of the silicone-containing polyol did not significantly lower the surface wettability, although ESCA-measured silicon content increased and physical properties were unfavourably affected by the incorporation of this co-soft segment. Incorporation of the siloxane-containing component resulted in increased platelet adhesion and fibrinogen deposition at most blood contact times in comparison with the other polyurethanes.


Asunto(s)
Materiales Biocompatibles , Recolección de Muestras de Sangre/instrumentación , Furanos , Polímeros , Poliuretanos , Animales , Plaquetas/citología , Adhesión Celular , Perros , Microanálisis por Sonda Electrónica , Ensayo de Materiales , Peso Molecular , Espectrofotometría Infrarroja , Propiedades de Superficie , Temperatura
17.
Biomaterials ; 10(4): 243-50, 1989 May.
Artículo en Inglés | MEDLINE | ID: mdl-2742952

RESUMEN

Thrombus deposition was measured on NHLBI-DTB Primary Reference Material polyethylene (PRM-PE) and polydimethylsiloxane (PRM-SR) and their commercially available counterparts, surgical grade Intramedic polyethylene and Dow Corning Silastic. Canine blood-contacting experiments evaluating short-term (up to 60 min) and longer-term (up to 24 h) thrombus deposition were used to quantitate adherent platelets on the lumenal surface of test materials ex vivo. A similar pattern of thrombus deposition and detachment was observed for all materials in both acute and chronic blood contact. Although differences in the wall shear rates affected the absolute numbers of adherent platelets, the relative levels of thrombus deposition showed similarities between the two experiments, with the polyethylene materials as a group showing slightly less deposition than the silicone rubber materials. The PRM-PE showed the least thrombus deposition at extended exposure to blood. The PRM-SR showed the most thrombus deposition in the acute term. The overall similarity in blood compatibility and surface properties indicates the need for the inclusion of less thromboresistant and more polar reference materials.


Asunto(s)
Materiales Biocompatibles , Adhesividad Plaquetaria , Prótesis e Implantes , Trombosis , Animales , Plaquetas/ultraestructura , Dimetilpolisiloxanos , Perros , Fibrinógeno/fisiología , Polietilenos , Elastómeros de Silicona , Siliconas , Propiedades de Superficie , Factores de Tiempo
18.
Ann Thorac Surg ; 49(4): 585-9; discussion 590, 1990 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2322054

RESUMEN

Intraoperative platelet-rich plasmapheresis allows autotransfusion of fresh, undamaged platelets and clotting factors at the completion of the operation. To evaluate this technology, we randomly assigned 100 consecutive patients who were to undergo an elective coronary bypass procedure and had normal clotting studies into the experimental (plasmapheresis) or the control group. Characteristics of both groups were similar, including average age (61.4 years versus 61.3 years [experimental versus control group]), sex (78% male versus 74% male), preoperative weight (80.9 kg versus 80.2 kg), preoperative red cell mass (1,989 mL versus 1,890 mL), perfusion time (102 minutes versus 106 minutes), and coagulation studies. Both internal mammary arteries were used in 68% of the patients. All patients had preoperative and postoperative blood volume determinations and complete clotting studies. Sixty-two variables related to bleeding were analyzed. Strict indications for transfusion were a hemoglobin level less than 7 g/100 mL in patients younger than 70 years and a hemoglobin level less than 8 g/100 mL in patients older than 70 years. The group receiving intraoperative plasmapheresis had a significant reduction in operative red cell mass loss (1,050 +/- 43 mL versus 1,226 +/- 61 mL; p = 0.021), a reduction in the average homologous transfusion (0.67 +/- 0.15 unit versus 1.8 +/- 0.25 units; p = 0.0002), and an increase in the percentage of patients not requiring blood transfusions (66% versus 32%; p = 0.001). This technique is useful in reducing postoperative blood loss and homologous transfusions.


Asunto(s)
Transfusión Sanguínea , Puente de Arteria Coronaria/efectos adversos , Hemorragia/prevención & control , Cuidados Intraoperatorios , Plasmaféresis , Coagulación Sanguínea , Tubos Torácicos , Volumen de Eritrocitos , Femenino , Hematócrito , Hemoglobinas/análisis , Hemorragia/sangre , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Distribución Aleatoria
19.
Orthop Clin North Am ; 19(3): 467-76, 1988 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-3380527

RESUMEN

This two-part study concerns the fate of 100 Charnley low-friction arthroplasties performed in 92 patients at The Hospital for Special Surgery. The first part of the study is a clinical and radiographic evaluation of the 40 hips that were available for follow-up at an average of 15.3 years after surgery. The second part is a survival analysis of the arthroplasty, the individual components, and the patients, using data from all 100 arthroplasties. The authors conclude that the vast majority of older patients who undergo cemented total hip arthroplasty will not require a subsequent arthroplasty, and will have satisfactory pain relief for the remainder of their lives.


Asunto(s)
Prótesis de Cadera , Actividades Cotidianas , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Articulación de la Cadera/diagnóstico por imagen , Articulación de la Cadera/fisiología , Humanos , Locomoción , Masculino , Persona de Mediana Edad , Movimiento , Dolor , Diseño de Prótesis , Falla de Prótesis , Radiografía , Reoperación
20.
J Cardiovasc Surg (Torino) ; 32(1): 1-7, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-2010437

RESUMEN

The effect of aspirin on red blood cell (RBC) loss and blood transfusions was evaluated prospectively in 100 consecutive patients, with normal bleeding times, undergoing elective coronary artery bypass (CABG) surgery. Patients taking 85-325 mgm of aspirin daily up to or within 48 hours of surgery (the "aspirin" group) were compared to patients not taking aspirin or those who had discontinued aspirin at least 4 days before surgery (the "no-aspirin" group). RBC loss was determined by measuring preoperative and postoperative RBC volume using RISA and 51Cr techniques. There were no significant differences, respectively, between the aspirin and no-aspirin groups for: RBC loss (1158 +/- 67 ml vs 1129 +/- 47 ml, p = 0.737), chest tube drainage (925 +/- 31 ml vs 844 +/- 70 ml, p = 0.553), and gm% discharge Hemoglobin (Hgb) (9.94 +/- 0.32 vs 9.49 +/- 1.4, p = 0.0148). Strict criteria for blood transfusions were employed: (1) intraoperative hematocrit of less than 21%, (2) postoperative Hgb of less than 7 gm% for patients less than 70 years old and (3) postoperative Hgb of less than 8 gm% for patients greater than 70 years old. There were no significant differences, respectively, between the aspirin and no-aspirin groups for units of blood transfused (1.32 +/- vs 1.21 +/- 0.20, p = 0.843) and patients not receiving transfusions during the entire hospitalization (44% vs 50%). Patients taking 85-325 mgm of aspirin with a normal bleeding time undergoing elective CABG did not have increased RBC loss or increased transfusion requirements. These results indicate it is not necessary to delay elective CABG surgery for the purpose of discontinuing aspirin.


Asunto(s)
Aspirina/farmacología , Pérdida de Sangre Quirúrgica , Transfusión Sanguínea , Puente de Arteria Coronaria , Volumen de Eritrocitos/efectos de los fármacos , Tiempo de Sangría , Plaquetas/efectos de los fármacos , Femenino , Hematócrito , Hemoglobinas/análisis , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
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