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1.
Glob Chang Biol ; 21(10): 3608-19, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25966973

RESUMEN

Estuaries are dynamic environments at the land-sea interface that are strongly affected by interannual climate variability. Ocean-atmosphere processes propagate into estuaries from the sea, and atmospheric processes over land propagate into estuaries from watersheds. We examined the effects of these two separate climate-driven processes on pelagic and demersal fish community structure along the salinity gradient in the San Francisco Estuary, California, USA. A 33-year data set (1980-2012) on pelagic and demersal fishes spanning the freshwater to marine regions of the estuary suggested the existence of five estuarine salinity fish guilds: limnetic (salinity = 0-1), oligohaline (salinity = 1-12), mesohaline (salinity = 6-19), polyhaline (salinity = 19-28), and euhaline (salinity = 29-32). Climatic effects propagating from the adjacent Pacific Ocean, indexed by the North Pacific Gyre Oscillation (NPGO), affected demersal and pelagic fish community structure in the euhaline and polyhaline guilds. Climatic effects propagating over land, indexed as freshwater outflow from the watershed (OUT), affected demersal and pelagic fish community structure in the oligohaline, mesohaline, polyhaline, and euhaline guilds. The effects of OUT propagated further down the estuary salinity gradient than the effects of NPGO that propagated up the estuary salinity gradient, exemplifying the role of variable freshwater outflow as an important driver of biotic communities in river-dominated estuaries. These results illustrate how unique sources of climate variability interact to drive biotic communities and, therefore, that climate change is likely to be an important driver in shaping the future trajectory of biotic communities in estuaries and other transitional habitats.


Asunto(s)
Distribución Animal , Biodiversidad , Cambio Climático , Peces/fisiología , Animales , California , Estuarios , Agua Dulce , Dinámica Poblacional , Agua de Mar
4.
Transplantation ; 72(11): 1795-802, 2001 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-11740391

RESUMEN

BACKGROUND: The systematic application of living-related and cadaveric, in situ split-liver transplantation has helped to alleviate the critical shortage of suitable-sized, pediatric donors. Undoubtedly, both techniques are beneficial and advantageous; however, the superiority of either graft source has not been demonstrated directly. Because of the potential living-donor risks, we reserve the living donor as the last graft option for pediatric recipients awaiting liver transplantation. Inasmuch as no direct comparison between these two graft types has been performed, we sought to perform a comparative analysis of the functional outcomes of left lateral segmental grafts procured from these donor sources to determine whether differences do exist. METHODS: A retrospective analysis of all liver transplants performed at a single institution between February 1984 and January 1999 was undertaken. Only pediatric (<18 years) recipients of left lateral segmental grafts procured from either living-related (LRD) or cadaveric, in situ split-liver (SLD) donors were included. A detailed analysis of preoperative, intraoperative, and postoperative variables was undertaken. Survival was estimated using the Kaplan-Meier method, and comparison of variables between groups was undertaken using the t test of Wilcoxon rank sum test. RESULTS: There were no significant differences in the preoperative variables between the 39 recipients of SLD grafts and 34 recipients of LRD grafts. The donors did differ significantly in mean age, ABO blood group matching, and preoperative liver function testing. Postoperative liver function testing revealed significant early differences in aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, prothrombin time, and alkaline phosphatase, with grafts from LRD performing better than those from SLD. SLD grafts also had significantly longer ischemia times and a higher incidence of graft loss owing to primary nonfunction and technical complications (9 vs. 2, P<0.05). However, six of these graft losses in the SLD group were because of technical or immunologic causes, which, theoretically, should not differ between the two groups. Furthermore, these graft losses did not negatively impact early patient survival as most patients were successfully rescued with retransplantation (30-day actuarial survival, 97.1% SLD vs. 94.1% LRD, P=0.745). In the surviving grafts, the early differences in liver function variables normalized. CONCLUSIONS: Inherent differences in both donor sources exist and account for differences seen in preoperative and intraoperative variables. Segmental grafts from LRD clearly performed better in the first week after transplantation as demonstrated by lower liver function variables and less graft loss to primary nonfunction. However, the intermediate function (7-30 days) of both grafts did not differ, and the early graft losses did not translate into patient death. Although minimal living-donor morbidity was seen in this series, the use of this donor type still carries a finite risk. We therefore will continue to use SLD as the primary graft source for pediatric patients awaiting liver transplantation.


Asunto(s)
Trasplante de Hígado/métodos , Hígado/fisiopatología , Adulto , Niño , Femenino , Humanos , Trasplante de Hígado/efectos adversos , Donadores Vivos , Masculino , Estudios Retrospectivos , Factores de Tiempo , Donantes de Tejidos , Resultado del Tratamiento
5.
Cytometry ; 45(2): 87-95, 2001 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-11590620

RESUMEN

BACKGROUND: Flow cytometry, in combination with retroviral expression libraries, is a powerful tool for genetic experimentation in mammalian cells. Expression libraries are transduced into cells engineered with a fluorescent reporter. Sorting for either bright or dim cells allows enrichment for specific inhibitors that alter reporter activity. This strategy has been used to isolate peptides and RNAs that either activate or suppress defined biochemical pathways. METHODS: Several variables contribute to the enrichment process: (1) the background of the fluorescence bioassay; (2) the mean fluorescence ratio between the induced and noninduced reporter cell populations; (3) the genetic penetrance, or strength, of the inhibitor; and (4) the multiplicity of infection (MOI). An experimental and theoretical analysis, including computer modeling, of these issues in the context of a mammalian cell bioassay was undertaken. RESULTS: MOI measurements were shown to be problematic. High MOI had little effect on enrichment early in the cycling process but a significant effect at later stages. Penetrance and background were critical throughout the process. Enrichments within about twofold of the theoretical maximum were observed. CONCLUSIONS: Caution should be exercised in MOI determination because of the danger of significant underestimation. High MOI is potentially advantageous early in the selection process but hinders enrichment in the later rounds. Modeling shows that MOI, assay background and clone penetrance are the principal variables that determine the success of transdominant selections by FACS.


Asunto(s)
Separación Celular/métodos , Citometría de Flujo/métodos , Genes Reporteros , Técnicas Genéticas , Animales , Línea Celular , Humanos , Retroviridae/fisiología , Programas Informáticos , Transducción Genética , Células Tumorales Cultivadas
6.
J Health Commun ; 6(2): 155-68, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11405079

RESUMEN

A theoretically based formative evaluation was conducted with coal miners in the Appalachian Mountains who were at high risk for noise-induced hearing loss (NIHL). The results of four focus groups indicate that despite high levels of knowledge, strong perceived severity of negative consequences, and strong perceived susceptibility to hearing loss, two main categories of barriers (environmental and individual) keep coal miners from using their hearing protection devices (HPD). Further analysis suggests that the environmental factors, rather than individual variables, more strongly influence decisions against protective actions. Recommendations and practical implications are offered.


Asunto(s)
Minas de Carbón , Dispositivos de Protección de los Oídos/estadística & datos numéricos , Pérdida Auditiva Provocada por Ruido/prevención & control , Ruido en el Ambiente de Trabajo/efectos adversos , Enfermedades Profesionales/prevención & control , Adulto , Femenino , Grupos Focales , Conocimientos, Actitudes y Práctica en Salud , Pérdida Auditiva Provocada por Ruido/etiología , Humanos , Masculino , Ruido en el Ambiente de Trabajo/prevención & control , Pennsylvania , West Virginia
7.
Health Educ Res ; 15(4): 463-7, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11066463

RESUMEN

This study evaluated a National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention, Alert concerning the risk and prevention of latex allergy among health care workers. It has been estimated that 8-12% of health care workers are sensitized to latex. NIOSH Alerts are publications that are intended to educate stakeholders about risks in the workplace; this Alert contained four recommendations for administrative control measures that hospital decision makers could adopt to reduce the risk of latex allergy to employees. The Alert was mailed to a random selection of Directors of Infection Control and Directors of Nursing in hospitals in the US. A random sample of these targeted recipients and a control group were surveyed by telephone (N = 298). Although nearly all of the respondents were concerned about latex allergy (96%), those reporting having seen the Alert were significantly more likely to report an intention to advocate for one or more of the control measures.


Asunto(s)
Adhesión a Directriz/estadística & datos numéricos , Administración Hospitalaria/normas , Hipersensibilidad al Látex/prevención & control , Salud Laboral , Personal de Hospital/normas , Toma de Decisiones en la Organización , Guantes Protectores/normas , Administración Hospitalaria/estadística & datos numéricos , Humanos , National Institute for Occupational Safety and Health, U.S. , Innovación Organizacional , Gestión de Riesgos , Estados Unidos
9.
BMJ ; 318(7184): 647-9, 1999 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-10066209

RESUMEN

OBJECTIVE: To review published criteria for specifically evaluating health related information on the world wide web, and to identify areas of consensus. DESIGN: Search of world wide web sites and peer reviewed medical journals for explicit criteria for evaluating health related information on the web, using Medline and Lexis-Nexis databases, and the following internet search engines: Yahoo!, Excite, Altavista, Webcrawler, HotBot, Infoseek, Magellan Internet Guide, and Lycos. Criteria were extracted and grouped into categories. RESULTS: 29 published rating tools and journal articles were identified that had explicit criteria for assessing health related web sites. Of the 165 criteria extracted from these tools and articles, 132 (80%) were grouped under one of 12 specific categories and 33 (20%) were grouped as miscellaneous because they lacked specificity or were unique. The most frequently cited criteria were those dealing with content, design and aesthetics of site, disclosure of authors, sponsors, or developers, currency of information (includes frequency of update, freshness, maintenance of site), authority of source, ease of use, and accessibility and availability. CONCLUSIONS: Results suggest that many authors agree on key criteria for evaluating health related web sites, and that efforts to develop consensus criteria may be helpful. The next step is to identify and assess a clear, simple set of consensus criteria that the general public can understand and use.


Asunto(s)
Internet/normas , Informática Médica/normas , Estudios de Evaluación como Asunto
10.
Somat Cell Mol Genet ; 25(4): 191-205, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11586787

RESUMEN

Quality bioassays are central to all approaches directed at understanding or perturbing the function of proteins. One type of cell-based bioassay involves an engineered reporter whose transcriptional activity serves as a readout for upstream signals of a biochemical pathway(s) that feeds into the reporter. We describe a general strategy for creating a mammalian reporter line with attributes suitable for a high complexity, en masse transdominant genetic screen. The basic criteria required of the mammalian cells engineered with the reporter include ease of maintenance, ease of sorting by FACS, ability to be transduced by retroviruses, and high expression of transduced peptides or cDNAs. For maximal enrichment during selection, the reporter line should have a relatively homogeneous response and a high signal-to-background ratio. We use a melanoma cell line transduced with a retinoic-acid-responsive promoter coupled to a GFP reporter as a case study to demonstrate the strategy. We characterize an optimized retinoic-acid-responsive reporter clone to determine the kinetics of reporter induction and decay in the presence and absence of retinoids. Dose-response studies reveal that the reporter responds to all-trans retinoic acid with an EC50 of approximately 1 nM. The strategy described is general and may be applied to create other reporter lines that respond to a specific stimulus.


Asunto(s)
Genes Dominantes , Genes Reporteros , Selección Genética , Secuencia de Bases , Separación Celular , ADN , Cartilla de ADN , Citometría de Flujo , Proteínas Fluorescentes Verdes , Humanos , Proteínas Luminiscentes/genética , Melanoma/genética , Melanoma/patología , Retroviridae/genética , Transducción Genética , Células Tumorales Cultivadas
12.
West J Med ; 170(6): 329-32, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18751150

RESUMEN

OBJECTIVE: To review published criteria for specifically evaluating health-related information on the World Wide Web and to identify areas of consensus in evaluation. DESIGN: Search of Web sites and peer-reviewed medical journals for explicit criteria for evaluating health-related information on the Web using Medline and Lexis-Nexis databases and the following Internet search engines: Yahoo!, Excite, Altavista, Webcrawler, HotBot, Infoseek, Magellan Internet Guide, and Lycos. Criteria were extracted and grouped into categories. RESULTS: Twenty-nine published rating tools and journal articles were identified that had explicit criteria for assessing health-related Web sites. Of the 165 criteria extracted from these tools and articles, 132 (80%) were grouped under 1 of 12 specific categories, and 33 (20%) were grouped as miscellaneous because they lacked specificity or were unique. The most frequently cited criteria were those dealing with the content, design, and aesthetics of a site; disclosure of authors, sponsors, or developers; currency of information (includes frequency of update, freshness, and maintenance of site); authority of source; ease of use; and accessibility and availability. CONCLUSIONS: Many authors agree on the key criteria for evaluating health-related Web sites and efforts to develop consensus criteria may be helpful. The next step is to identify and assess a clear, simple set of consensus criteria that the general public can understand and use.

13.
JAMA ; 280(15): 1371-5, 1998 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-9794322

RESUMEN

Information and communication technologies may help reduce health disparities through their potential for promoting health, preventing disease, and supporting clinical care for all. Unfortunately, those who have preventable health problems and lack health insurance coverage are the least likely to have access to such technologies. Barriers to access include cost, geographic location, illiteracy, disability, and factors related to the capacity of people to use these technologies appropriately and effectively. A goal of universal access to health information and support is proposed to augment existing initiatives to improve the health of individuals and the public. Both public- and private-sector stakeholders, particularly government agencies and private corporations, will need to collaboratively reduce the gap between the health information "haves" and "have-nots." This will include supporting health information technology access in homes and public places, developing applications for the growing diversity of users, funding research on access-related issues, ensuring the quality of health information and support, enhancing literacy in health and technology, training health information intermediaries, and integrating the concept of universal access to health information and support into health planning processes.


Asunto(s)
Atención a la Salud , Internet , Informática Médica , Salud Pública , Necesidades y Demandas de Servicios de Salud , Sector Privado , Sector Público
14.
Proc Natl Acad Sci U S A ; 95(13): 7508-13, 1998 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-9636180

RESUMEN

Genetic selections that use proteinaceous transdominant inhibitors encoded by DNA libraries to cause mutant phenocopies may facilitate genetic analysis in traditionally nongenetic organisms. We performed a selection for random short peptides and larger protein fragments (collectively termed "perturbagens") that inhibit the yeast pheromone response pathway. Peptide and protein fragment perturbagens that permit cell division in the presence of pheromone were recovered. Two perturbagens were derived from proteins required for pheromone response, and an additional two were derived from proteins that may negatively influence the pheromone response pathway. Furthermore, three known components of the pathway were identified as probable perturbagen targets based on physical interaction assays. Thus, by selection for transdominant inhibitors of pheromone response, multiple pathway components were identified either directly as gene fragments or indirectly as the likely targets of specific perturbagens. These results, combined with the results of previous work [Holzmayer, T. A., Pestov, D. G. & Roninson, I. B. (1992) Nucl. Acids. Res. 20, 711-717; Whiteway, M., Dignard, D. & Thomas, D. Y. (1992) Proc. Natl. Acad. Sci. USA 89, 9410-9414; and Gudkov, A. V., Kazarov, A. R., Thimmapaya, R., Axenovich, S. A., Mazo, I. A. & Roninson, I. B. (1994) Proc. Natl. Acad. Sci. USA 91, 3744-3748], suggest that transdominant genetic analysis of the type described here will be broadly applicable.


Asunto(s)
Ciclo Celular/genética , Modelos Genéticos , Epistasis Genética , Genes Dominantes , Técnicas Genéticas , Factor de Apareamiento , Fragmentos de Péptidos/química , Fragmentos de Péptidos/aislamiento & purificación , Fragmentos de Péptidos/farmacología , Biblioteca de Péptidos , Péptidos/antagonistas & inhibidores , Péptidos/genética , Fenotipo , Feromonas/genética , Feromonas/fisiología , Saccharomyces cerevisiae
15.
Transplantation ; 66(12): 1604-11, 1998 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-9884246

RESUMEN

BACKGROUND: We have previously reported a 10% incidence of posttransplant lymphoproliferative disease (PTLD) in pediatric patients receiving first liver grafts and primarily immunosuppressed with tacrolimus. To decrease the incidence of PTLD, we developed a protocol utilizing preemptive intravenous ganciclovir in high-risk recipients (i.e., donor (D)+, recipient (R)-), combined with serial monitoring of peripheral blood for Epstein Barr virus (EBV) by polymerase chain reaction (PCR). METHODS: Consecutive pediatric recipients of a first liver graft were immunosuppressed with oral tacrolimus (both induction and maintenance), and low-dose prednisone. EBV serologies were obtained at the time of orthotopic liver transplant in recipients and donors. Recipients were divided into groups: group 1, high-risk (D+R-), and group 2, low-risk (D+R+; D-R-; D-R+). In group 1 (high-risk), all patients received a minimum of 100 days of intravenous ganciclovir (6-10 mg/kg/day), while, in group 2 (low-risk), patients received intravenous ganciclovir during their initial hospitalization and then were converted to oral acyclovir (40 mg/kg/day) at discharge. Semiquantitative EBV-PCR determinations were made at 1-2-month intervals. In both groups, patients with an increasing viral copy number by EBV-PCR had tacrolimus levels decreased to 2-5 ng/ml. Tacrolimus was stopped, and intravenous ganciclovir reinstituted for PTLD. A positive EBV-PCR with symptoms, but negative histology, was defined as EBV disease; PTLD was defined as histologic evidence of polyclonal or monoclonal B cell proliferation. RESULTS: Forty children who had survived greater than 2 months were enrolled. There were 18 children in group 1 (high-risk; mean age of 14+/-15 months and mean follow-up time of 243+/-149 days) and 22 children in group 2 (low-risk; mean age of 64+/-65 months and follow-up time of 275+/-130 days). In group 1 (high-risk), there was no PTLD and one case of EBV disease (mononucleosis-like syndrome), which resolved. In group 2 (low-risk), there were two cases of PTLD; both resolved when tacrolimus was stopped. Both children were 8 months old at time of transplant. Neither received OKT3, and they had one and two episodes of steroid-sensitive rejection, respectively. One child had EBV disease (mild hepatitis), which resolved. CONCLUSIONS: Since instituting this protocol, the overall incidence of PTLD has fallen from 10% to 5% for children receiving primary tacrolimus therapy after OLT. No high-risk pediatric liver recipient treated preemptively with intravenous ganciclovir developed PTLD. Both children with PTLD were less than 1 year at OLT and considered low-risk. However, their positive EBV antibody titers may have been maternal in origin and not have offered long-term protection. Serial monitoring of EBV-PCR after pediatric OLT is recommended to decrease the risk of PTLD by allowing early detection of EBV infection, which is then managed by decreasing immunosuppression and continuing intravenous ganciclovir.


Asunto(s)
Antivirales/uso terapéutico , Ganciclovir/uso terapéutico , Infecciones por Herpesviridae/prevención & control , Herpesvirus Humano 4/aislamiento & purificación , Trasplante de Hígado/efectos adversos , Trastornos Linfoproliferativos/prevención & control , Infecciones Tumorales por Virus/prevención & control , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Trastornos Linfoproliferativos/etiología , Trastornos Linfoproliferativos/terapia , Proyectos Piloto , Reacción en Cadena de la Polimerasa , Estudios Prospectivos
16.
J Health Psychol ; 1(3): 261-77, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22011991

RESUMEN

This article presents a health lifestyle audience segmentation analysis based primarily on social cognitive theory. Two linked mail surveys were conducted among a representative group of US adults (N = 2967). Segmentation variables included data on five health behaviors (smoking, alcohol consumption, physical activity, nutrition and weight control), internal personal and social/ environmental variables associated with each of the health behaviors, as well as health value, sensation- seeking, life satisfaction and age. K-means classification analysis was employed; seven health lifestyles were identified. The majority of the health lifestyles are reliable, and as a whole, all demonstrate both discriminative, construct and predictive validity. The health-lifestyle audience segments are briefly profiled, and an argument is made that health- lifestyle segmentation, more than demographic or behavioral segmentation alone, can advance the goals of public health communication.

17.
Am J Surg ; 169(5): 529-32, 1995 May.
Artículo en Inglés | MEDLINE | ID: mdl-7538267

RESUMEN

BACKGROUND: Living-donor (LD) liver transplantation has been developed as an alternative to overcome the shortage of cadaver donor organs for pediatric recipients. PATIENTS AND METHODS: We reviewed our experience with 9 LD transplants performed between August 25, 1993 and August 3, 1994. The median recipient age and weight were 13 months and 10 kilograms. Left lateral segments from parental donors, with aortic inflow via saphenous vein grafts, were used in all cases. RESULTS: At a median follow-up of 160 days, all donors were alive and well. Recipient and graft survival were both 89%. Rates of hepatic artery thrombosis, portal vein thrombosis, biliary complications, and acute rejection were 22%, 11%, 11%, and 67%, respectively. CONCLUSIONS: Excellent outcome can be achieved with LD liver transplantation in small children with minimal donor risk. This procedure has the potential to emerge as the preferred treatment for pediatric liver transplant candidates for whom it is an option.


Asunto(s)
Familia , Oclusión de Injerto Vascular/epidemiología , Rechazo de Injerto/epidemiología , Supervivencia de Injerto , Trasplante de Hígado/métodos , Donantes de Tejidos , Obtención de Tejidos y Órganos/métodos , Adolescente , Adulto , Niño , Terapia Combinada , Femenino , Estudios de Seguimiento , Oclusión de Injerto Vascular/terapia , Rechazo de Injerto/terapia , Hospitales Universitarios , Humanos , Trasplante de Hígado/mortalidad , Los Angeles , Masculino , Persona de Mediana Edad , Muromonab-CD3/uso terapéutico , Cuidados Posoperatorios , Reoperación , Factores de Riesgo , Tasa de Supervivencia , Tacrolimus/uso terapéutico , Factores de Tiempo , Resultado del Tratamiento
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