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1.
Ecotoxicology ; 24(6): 1250-8, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26002221

RESUMEN

Metals constitute an important group of abiotic stressors that elicit stress responses in marine algae that include the production of reactive oxygen species (ROS). Silver (Ag) is a highly toxic metal to organisms but despite this there are relatively few studies on how it affects marine macroalgae (seaweeds). In a landmark study published in 1977 the first information was provided on the accumulation of Ag in Fucus spp. (Phaeophyceae) from the Looe estuary, located in south-west England, an area with a long history of mining activity. In the present study, the estuary has been re-visited and the patterns of Ag accumulation in two Fucus spp. and sediment re-examined after 35 years. We conclude that Ag concentrations in sediment and macroalgae from specific sites within the catchment remain high, but more generally sediment concentrations have declined by approximately 65 % and the dissolved, bioavailable fraction by 24 % over this period. In addition, from laboratory studies we provide data on the speciation and toxic effects of Ag under different salinity regimes in the euryhaline brown seaweed, Fucus ceranoides. From these exposure experiments, it was found that with increasing Ag concentrations growth was inhibited and lipid peroxidation associated with ROS production increased. The magnitude of the toxic effects was greater at a salinity of 10 than 28 psu which reflects the greater bioavailability of the toxic species of Ag (Ag(+) and AgCl(0)) at reduced salinities. These findings emphasise the importance of investigating the effects of metal pollution in conjunction with other, natural, environmental stressors such as salinity.


Asunto(s)
Fucus/efectos de los fármacos , Algas Marinas/efectos de los fármacos , Plata/toxicidad , Contaminantes Químicos del Agua/toxicidad , Inglaterra , Monitoreo del Ambiente , Estuarios , Plata/metabolismo , Contaminantes Químicos del Agua/metabolismo
2.
Bone Joint J ; 96-B(8): 1098-105, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25086127

RESUMEN

The pre-operative differentiation between enchondroma, low-grade chondrosarcoma and high-grade chondrosarcoma remains a diagnostic challenge. We reviewed the accuracy and safety of the radiological grading of cartilaginous tumours through the assessment of, first, pre-operative radiological and post-operative histological agreement, and second the rate of recurrence in lesions confirmed as high-grade on histology. We performed a retrospective review of major long bone cartilaginous tumours managed by curettage as low grade between 2001 and 2012. A total of 53 patients with a mean age of 47.6 years (8 to 71) were included. There were 23 men and 30 women. The tumours involved the femur (n = 20), humerus (n = 18), tibia (n = 9), fibula (n = 3), radius (n = 2) and ulna (n = 1). Pre-operative diagnoses resulted from multidisciplinary consensus following radiological review alone for 35 tumours, or with the addition of pre-operative image guided needle biopsy for 18. The histologically confirmed diagnosis was enchondroma for two (3.7%), low-grade chondrosarcoma for 49 (92.6%) and high-grade chondrosarcoma for two (3.7%). Three patients with a low-grade tumour developed a local recurrence at a mean of 15 months (12 to 17) post-operatively. A single high-grade recurrence (grade II) was treated with tibial diaphyseal replacement. The overall recurrence rate was 7.5% at a mean follow-up of 4.7 years (1.2 to 12.3). Cartilaginous tumours identified as low-grade on pre-operative imaging with or without additional image-guided needle biopsy can safely be managed as low-grade without pre-operative histological diagnosis. A few tumours may demonstrate high-grade features histologically, but the rates of recurrence are not affected.


Asunto(s)
Neoplasias Óseas/cirugía , Enfermedades de los Cartílagos/cirugía , Condroma/cirugía , Condrosarcoma/cirugía , Legrado/métodos , Adolescente , Adulto , Anciano , Biopsia con Aguja , Neoplasias Óseas/diagnóstico , Enfermedades de los Cartílagos/diagnóstico , Niño , Condroma/diagnóstico , Condrosarcoma/diagnóstico , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Cuidados Preoperatorios/métodos , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
3.
Osteoarthritis Cartilage ; 19(6): 639-46, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21251985

RESUMEN

OBJECTIVE: This study was designed to evaluate the long-term safety and effectiveness of repeated doses of the humanized anti-nerve growth factor antibody, tanezumab, during open-label treatment of patients with OA knee pain. DESIGN: The current study (clinicaltrials.gov identifier: NCT00399490) was a multicenter, phase II, open-label, multiple-dose extension of an earlier randomized clinical trial. All patients (N=281) received infusions of tanezumab 50µg/kg on Days 1 and 56 with subsequent doses administered at 8-week intervals (up to a total of eight infusions). The primary endpoint of this study was safety. Effectiveness evaluations included overall knee pain, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index subscales, and subject global assessment (SGA) of response to therapy on 0-100 point visual analog scales. RESULTS: Repeated administration of tanezumab resulted in a low incidence of treatment-related adverse events (AEs; 7.5%). The rate of serious AEs was also low (2.8%) with none considered treatment-related. Few AEs of abnormal peripheral sensation were reported; hypoesthesia was reported by nine patients (3.2%), paresthesia by seven patients (2.5%), and hyperesthesia, peripheral neuropathy, and sensory disturbance were each reported by one patient (0.4% for each). Most AEs of abnormal peripheral sensation were rated as mild (95%) and the majority (65%) resolved before study completion. At Week 8, overall knee pain and SGA improved from baseline by a mean (± standard error) of -12.8 (±1.78) and 8.0 (±1.66), respectively. Similar improvements occurred for WOMAC subscales. CONCLUSIONS: Repeated injections of tanezumab in patients with moderate to severe knee OA provide continued pain relief and improved function with a low incidence of side effects. Additional studies to define the efficacy and duration of pain reduction and to provide a more complete assessment of long-term safety are warranted.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Osteoartritis de la Rodilla/tratamiento farmacológico , Dolor/tratamiento farmacológico , Receptor de Factor de Crecimiento Nervioso/antagonistas & inhibidores , Anciano , Anticuerpos Monoclonales Humanizados , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/complicaciones , Osteoartritis de la Rodilla/fisiopatología , Dolor/etiología
4.
Aquat Toxicol ; 66(3): 293-305, 2004 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-15129771

RESUMEN

The herbicides Irgarol 1051 (2-(tert-butylamino)-4-cyclopropylamino)-6-(methylthio)-1,3,5-triazine) and Diuron (3-(3',4'-dichlorophenyl)-1,1-dimethylurea) are commonly incorporated into antifouling paints to boost the efficacy of the compound towards algae. Previous investigations have identified environmental concentrations of these herbicides as being a threat to non-target organisms, such as seagrasses. Their individual toxicity has been assessed, but they can co-occur and interact, potentially increasing their toxicity and the threat posed to seagrass meadows. Chlorophyll fluorescence (Fv:Fm) and leaf specific biomass ratio (representing plant growth) were examined in Zostera marina L. after a 10-day exposure to the individual herbicides. The EC20 for each herbicide was determined and these then used in herbicide mixtures to assess their interactive effects. Irgarol 1051 was found to be more toxic than Diuron with lowest observable effect concentrations for Fv:Fm reduction of 0.5 and 1.0 +/- microg/l and 10-day EC50 values of 1.1 and 3.2 microg/l, respectively. Plants exposed to Irgarol 1051 and Diuron showed a significant reduction in growth at concentrations of 1.0 and 5.0 microg/l, respectively. When Z. marina was exposed to mixtures, the herbicides commonly interacted additively or antagonistically, and no significant further reduction in photosynthetic efficiency was found at any concentration when compared to plants exposed to the individual herbicides. However, on addition of the Diuron EC20 to varying Irgarol 1051 concentrations and the Irgarol 1051 EC20 to varying Diuron concentrations, significant reductions in Fv:Fm were noted at an earlier stage. The growth of plants exposed to Diuron plus the Irgarol 1051 EC20 were significantly reduced when compared to plants exposed to Diuron alone, but only at the lower concentrations. Growth of plants exposed to Irgarol 1051 and the Diuron EC20 showed no significant reduction when compared to the growth of plants exposed to Irgarol 1051 alone. Despite the addition of the EC20 not eliciting a further significant reduction when compared to the herbicides acting alone for most of the mixtures, the lowest observable significant effect concentration for growth and photosynthetic efficiency decreased to 0.5 microg/l for both herbicides. Irgarol 1051 and Diuron have been shown to occur together in concentrations above 0.5 microg/l, suggesting that seagrasses may be experiencing reduced photosynthetic efficiency and growth as a result.


Asunto(s)
Diurona/toxicidad , Herbicidas/toxicidad , Fotosíntesis/efectos de los fármacos , Triazinas/toxicidad , Zosteraceae/efectos de los fármacos , Análisis de Varianza , Clorofila/metabolismo , Fluorescencia , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/crecimiento & desarrollo , Agua de Mar , Pruebas de Toxicidad , Reino Unido , Zosteraceae/crecimiento & desarrollo
5.
Aquat Toxicol ; 64(2): 201-13, 2003 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-12799112

RESUMEN

Through a series of comparative experiments the relative effects of copper (Cu) exposure on the growth and physiology (chlorophyll fluorescence, ion leakage, O(2) evolution and pigmentation) of the red seaweed Gracilariopsis longissima was investigated. Of the various physiological end-points measured, growth proved to be the most sensitive with reductions in relative growth rate (RGR) observed at a concentration of 12.5 microg l(-1) Cu, with zero growth above about 300 microg l(-1). A significant increase in ion leakage and reduction in phycobiliprotein concentrations were evident, but only at the highest concentration tested (500 microg l(-1)), at which point shrinkage of apical tips also occurred. Photosynthetic rates, as measured by chlorophyll fluorescence and oxygen evolution, were first impaired at 250 microg l(-1), with a 30% reduction in photosynthetic efficiency (F(v)/F(m)) and a 60% reduction in oxygen evolution. There were no discernible effects on respiration rates or chlorophyll a and beta-carotene content over this concentration range. It was hypothesised that the observed uncoupling of growth and photosynthesis at low Cu concentrations might be explained by the release of dissolved organic matter (DOC), resulting in less available energy for growth. No such increase in DOC was apparent. Alternative explanations to account for the uncoupling, including the diversion of energy for maintenance of cell integrity and induction of protective mechanisms, are discussed.


Asunto(s)
Cobre/toxicidad , Rhodophyta/metabolismo , Algas Marinas/metabolismo , Contaminantes del Agua/toxicidad , Permeabilidad de la Membrana Celular/efectos de los fármacos , Respiración de la Célula/efectos de los fármacos , Clorofila , Relación Dosis-Respuesta a Droga , Fluorescencia , Compuestos Orgánicos/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Fotosíntesis/efectos de los fármacos , Pigmentos Biológicos/metabolismo , Rhodophyta/crecimiento & desarrollo , Algas Marinas/crecimiento & desarrollo
6.
J Med Ethics ; 28(3): 192-5; discussion 202, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12042408

RESUMEN

It is claimed by the future like ours anti-abortion argument that since killing adult humans is wrong because it deprives them of a future of value and the fetus has a future of value, killing fetuses is wrong in the same way that killing adult human beings is wrong. In The morality of abortion and the deprivation of futures (this journal, April 2000) I argued that the persuasive power of this argument rests upon an equivocation on the term "future of value". If the expression means "a potential future of value" then the moral claim is implausible because people do not in general have rights to what they need to fulfill their potential; if the expression means "self-represented future of value" then the argument fails because the fetus does not represent its future. Under no interpretation is the argument sound. In Deprivations, futures and the wrongness of killing (this journal, December 2001) Donald Marquis, author of the future like ours argument, responds at length to this objection. In the present essay the focus of the debate shifts to the proper interpretation of the right not to be killed. Donald Marquis argues that this liberty right entails the welfare right to the means necessary to sustain life; I argue that the right not to be killed does not entail unlimited welfare rights. On Marquis's view, the right not to be killed confers upon the fetus the right to whatever it takes to sustain life; on the view I defend, the right not to be killed does not confer upon the fetus or anyone else the right to another person's body. On Marquis's view, abortion is almost never permissible; on my view abortion is almost always permissible.


Asunto(s)
Aborto Legal/normas , Ética , Feto , Principios Morales , Valor de la Vida , Femenino , Homicidio , Derechos Humanos , Humanos , Embarazo
8.
Adv Space Res ; 27(9): 1547-56, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11695435

RESUMEN

Bioregenerative life support technologies for space application are advantageous if they can be constructed using locally available materials, and rely on renewable energy resources, lessening the need for launch and resupply of materials. These same characteristics are desirable in the global Earth environment because such technologies are more affordable by developing countries, and are more sustainable long-term since they utilize less non-renewable, imported resources. Subsurface flow wetlands (wastewater gardens(TM)) were developed and evaluated for wastewater recycling along the coast of Yucatan. Emergy evaluations, a measure of the environmental and human economic resource utilization, showed that compared to conventional sewage treatment, wetland wastewater treatment systems use far less imported and purchased materials. Wetland systems are also less energy-dependent, lessening dependence on electrical infrastructure, and require simpler maintenance since the system largely relies on the ecological action of microbes and plants for their efficacy. Detailed emergy evaluations showed that wetland systems use only about 15% the purchased emergy of conventional sewage systems, and that renewable resources contribute 60% of total emergy used (excluding the sewage itself) compared to less than 1% use of renewable resources in the high-tech systems. Applied on a larger scale for development in third world countries, wetland systems would require the electrical energy of conventional sewage treatment (package plants), and save of total capital and operating expenses over a 20-year timeframe. In addition, there are numerous secondary benefits from wetland systems including fiber/fodder/food from the wetland plants, creation of ecosystems of high biodiversity with animal habitat value, and aesthestic/landscape enhancement of the community. Wetland wastewater treatment is an exemplar of ecological engineering in that it creates an interface ecosystem to handle byproducts of the human economy, maximizing performance of the both the natural economy and natural ecosystems. Wetland systems accomplish this with far greater resource economy than other sewage treatment approaches, and thus offer benefits for both space and Earth applications.


Asunto(s)
Conservación de los Recursos Naturales , Sistemas Ecológicos Cerrados , Fuentes Generadoras de Energía , Aguas del Alcantarillado , Eliminación de Residuos Líquidos/métodos , Electricidad , Humanos , Sistemas de Manutención de la Vida/instrumentación , México , Vuelo Espacial/instrumentación , Eliminación de Residuos Líquidos/economía , Eliminación de Residuos Líquidos/instrumentación
9.
Biochemistry ; 40(44): 13237-45, 2001 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-11683632

RESUMEN

The interaction of the human adenovirus proteinase (AVP) with various DNAs was characterized. AVP requires two cofactors for maximal activity, the 11-amino acid residue peptide from the C-terminus of adenovirus precursor protein pVI (pVIc) and the viral DNA. DNA binding was monitored by changes in enzyme activity or by fluorescence anisotropy. The equilibrium dissociation constants for the binding of AVP and AVP-pVIc complexes to 12-mer double-stranded (ds) DNA were 63 and 2.9 nM, respectively. DNA binding was not sequence specific; the stoichiometry of binding was proportional to the length of the DNA. Three molecules of the AVP-pVIc complex bound to 18-mer dsDNA and six molecules to 36-mer dsDNA. When AVP-pVIc complexes bound to 12-mer dsDNA, two sodium ions were displaced from the DNA. A Delta of -4.6 kcal for the nonelectrostatic free energy of binding indicated that a substantial component of the binding free energy results from nonspecific interactions between the AVP-pVIc complex and DNA. The cofactors altered the interaction of the enzyme with the fluorogenic substrate (Leu-Arg-Gly-Gly-NH)2-rhodamine. In the absence of any cofactor, the Km was 94.8 microM and the kcat was 0.002 s(-1). In the presence of adenovirus DNA, the Km decreased 10-fold and the kcat increased 11-fold. In the presence of pVIc, the Km decreased 10-fold and the kcat increased 118-fold. With both cofactors present, the kcat/Km ratio increased 34000-fold, compared to that with AVP alone. Binding to DNA was coincident with stimulation of proteinase activity by DNA. Although other proteinases have been shown to bind to DNA, stimulation of proteinase activity by DNA is unprecedented. A model is presented suggesting that AVP moves along the viral DNA looking for precursor protein cleavage sites much like RNA polymerase moves along DNA looking for a promoter.


Asunto(s)
Adenovirus Humanos/enzimología , Cisteína Endopeptidasas/metabolismo , ADN Viral/metabolismo , Fragmentos de Péptidos/metabolismo , Proteínas Virales/metabolismo , Adenovirus Humanos/genética , Sitios de Unión , Cisteína Endopeptidasas/química , Cartilla de ADN/química , Activación Enzimática , Polarización de Fluorescencia , Humanos , Cinética , Ligandos , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Conformación Proteica , Proteínas Virales/química , Proteínas Virales/genética
10.
Curr Opin Investig Drugs ; 2(5): 613-6, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11569932

RESUMEN

A new form of antiviral clinical therapy is proposed in which three different drugs are administered against three different targets on the same virus-coded protein. If the physiological functions of the three different target sites are not independent of each other, then a mutation conferring drug resistance at one site may alter the physiological functions at the other sites and further drug resistance may not arise. The adenovirus proteinase, with its two cofactors that act synergistically on enzyme activity, may be a good model system within which to test the efficacy of this form of combination therapy.


Asunto(s)
Antivirales/farmacología , Farmacorresistencia Microbiana , Virus/efectos de los fármacos , Animales , Replicación del ADN/efectos de los fármacos , ADN Viral/biosíntesis , Combinación de Medicamentos , Farmacorresistencia Microbiana/genética , Humanos , Virus/enzimología , Virus/genética
11.
Environ Int ; 27(1): 43-7, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11488389

RESUMEN

The commonest species of red, brown, and green macroalgae were sampled from a range of biotopes in the Aegean Sea and analysed for five different trace metals. Significant differences in metal concentrations were found among different seaweed species from the same biotope. The concentrations of metals in the various seaweed species may reflect their morphology, with those having a larger surface area having a greater internal content. Different species of seaweed have different affinities for different heavy metals. This may reflect competition between metals for binding or uptake sites in the seaweed. Comparing metal concentrations in algae among the studied sampling stations clearly indicates that the degree of accumulation depends not only on human activities but also on the geology of the specific area. While seaweed can be used successfully to assess the levels of heavy metals in the marine environment, not all elevated concentrations of heavy metals necessarily reflect increased levels of pollution. Indeed, the high concentrations of certain metals, e.g., Ni, found in our seaweed samples reflected the metaliferrous nature of the rock. It is therefore important to take account of a region's geology before attempting to interpret the data.


Asunto(s)
Eucariontes/química , Metales Pesados/análisis , Sitios de Unión , Monitoreo del Ambiente , Sedimentos Geológicos/química , Metales Pesados/farmacocinética , Distribución Tisular
12.
Curr Med Chem ; 8(8): 933-9, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11375760

RESUMEN

Combination therapy in the treatment of viral infections in which, for example, three different drugs against three different targets on three independent proteins are administered, has been highly successful clinically. However, it is only a matter of time before a virus will arise resistant to all three drugs, because the mutations leading to drug resistance are independent of each other. But, what if the mutations leading to drug resistance are not independent of each other, but confer some cost to the virus? If the cost is too great, than resistance may not arise. To impose such a cost in the clinical treatment of viral infections, we propose a new form of combination therapy. Here, three different drugs against three different targets on the same virus-coded protein are administered. If the physiological functions of the three different target sites are not independent of each other, then, a mutation at one site may alter the physiological functions at the other sites. We present a model system in which to test the efficacy of this new form of triple combination therapy. Human adenovirus has a virus-coded proteinase that is essential for the synthesis of infectious virus. It contains an active site and two cofactor binding sites; the functions of the active site are dependent upon the cofactors interacting with their binding sites. We describe how to obtain drugs against the three different sites.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Modelos Biológicos , Adenoviridae/enzimología , Sitios de Unión , Cisteína Endopeptidasas/química , Cisteína Endopeptidasas/efectos de los fármacos , Cisteína Endopeptidasas/genética , ADN/efectos de los fármacos , ADN/metabolismo , Farmacorresistencia Microbiana/fisiología , Quimioterapia Combinada , VIH/efectos de los fármacos , VIH/enzimología , Inhibidores de Integrasa VIH/uso terapéutico , Inhibidores de la Proteasa del VIH/uso terapéutico , Humanos , Inhibidores de la Transcriptasa Inversa/uso terapéutico
13.
J Med Ethics ; 26(2): 103-7, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10786320

RESUMEN

In an influential essay entitled Why abortion is wrong, Donald Marquis argues that killing actual persons is wrong because it unjustly deprives victims of their future; that the fetus has a future similar in morally relevant respects to the future lost by competent adult homicide victims, and that, as consequence, abortion is justifiable only in the same circumstances in which killing competent adult human beings is justifiable. The metaphysical claim implicit in the first premise, that actual persons have a future of value, is ambiguous. The Future Like Ours argument (FLO) would be valid if "future of value" were used consistently to mean either "potential future of value" or "self-represented future of value", and FLO would be sound if one or the other interpretation supported both the moral claim and the metaphysical claim, but if, as I argue, any interpretation which makes the argument valid renders it unsound, then FLO must be rejected. Its apparent strength derives from equivocation on the concept of "a future of value".


Asunto(s)
Aborto Legal , Principios Morales , Personeidad , Valor de la Vida , Feto Abortado , Adulto , Femenino , Humanos , Relaciones Materno-Fetales , Responsabilidad Parental , Embarazo , Mujeres Embarazadas
14.
Proc Natl Acad Sci U S A ; 97(8): 4011-6, 2000 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-10725410

RESUMEN

Arf family GTP-binding proteins are best characterized as regulators of membrane traffic, but recent studies indicate an additional role in cytoskeletal organization. An Arf GTPase-activating protein of the centaurin beta family, ASAP1 (also known as centaurin beta4), binds Arf and two other known regulators of the actin cytoskeleton, the tyrosine kinase Src and phosphatidylinositol 4,5-bisphosphate. In this paper, we show that ASAP1 localizes to focal adhesions and cycles with focal adhesion proteins when cells are stimulated to move. Overexpression of ASAP1 altered the morphology of focal adhesions and blocked both cell spreading and formation of dorsal ruffles induced by platelet-derived growth factor (PDGF). On the other hand, ASAP1, with a mutation that disrupted GTPase-activating protein activity, had a reduced effect on cell spreading and increased the number of cells forming dorsal ruffles in response to PDGF. These data support a role for an Arf GTPase-activating protein, ASAP1, as a regulator of cytoskeletal remodeling and raise the possibility that the Arf pathway is a target for PDGF signaling.


Asunto(s)
Actinas/metabolismo , Proteínas Portadoras/metabolismo , Citoesqueleto/metabolismo , Fosfoproteínas/metabolismo , Células 3T3 , Secuencia de Aminoácidos , Animales , Ratones , Datos de Secuencia Molecular , Plásmidos , Dedos de Zinc
15.
Mar Environ Res ; 49(1): 67-78, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11444015

RESUMEN

Species of Spartina are potentially useful for biomonitoring coastal systems because they are abundant in the intertidal and have a wide geographic distribution in temperate zones. In this study, three indexes of physiological stress, thiolic protein concentration, adenylic energy charge (AEC) index [AEC = ATP + 0.5ADP/(ATP + ADP + AMP)] and photosynthetic efficiency (Fv/Fm), are measured in Spartina maritima plants collected at four sites and compared with metal concentrations in the sediments and Spartina tissues. Two sites were close to urban centers and two were located further away, in less contaminated areas. Concentrations of copper, cadmium, lead and zinc were determined by atomic absorption spectrophotometry, thiolic proteins were determined by polarography and adenilic nucleotides were determined by high performance liquid chromatography. Photosynthetic efficiencies were measured with a fluorometer. The sediments of sites closer to urban centers had higher concentrations of metals than the sites located further away. Metal concentration within plants did not follow this spatial pattern, probably due to spatial differences in metal bioavailability, uptake rates, internal transport and excretion processes. Concentrations of all metals studied were higher in underground plant structures than aerial, except cadmium whose levels were not significantly different. On the other hand, the stress indexes followed the spatial pattern of metals in the sediment. Thiolic protein concentrations were higher in plants from polluted sites, and were three to four times higher in aerial than in underground plant structures. Leaf AEC ratios and photosynthetic efficiencies were lower in plants from polluted sites indicating that they were growing under stressful conditions. We conclude that the use of these indexes in S. maritima represent a useful tool to monitor contamination in Ria Formosa lagoon as they provide an integrated measure of the toxicological burden of contamination.


Asunto(s)
Contaminantes Ambientales/análisis , Magnoliopsida/química , Monitoreo del Ambiente/métodos , Fotosíntesis , Portugal
16.
Arch Otolaryngol Head Neck Surg ; 125(12): 1371-4, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10604417

RESUMEN

OBJECTIVE: To quantitate the functional morbidity to the hand and wrist following harvest of a radial forearm fasciocutaneous free flap. DESIGN: Prospective case-control study, with each patient providing his or her internal control, comparing preoperative and postoperative operated to nonoperated forearms. SETTING: Tertiary care hospital in large metropolitan area. PATIENTS: A consecutive sample of 11 patients who underwent a radial forearm free flap reconstruction of the head and neck from April 1997 to May 1998. MAIN OUTCOME MEASURES: Range of motion of the wrist (flexion and extension, ulnar and radial deviation), grip and pinch strength, and sharp and dull sensation in the distribution of the radial, ulnar, and median nerves. RESULTS: Statistically significant differences (P<.05) were measured in wrist flexion, pinch strength, and sharp sensation in the anatomical snuffbox of the operated forearm. No subjective complaints of loss of function were reported by any patient. CONCLUSIONS: Donor-site functional morbidity associated with harvest of the radial forearm fasciocutaneous free flap is measurable. The statistical differences found do not translate into subjective patient complaints of everyday functional morbidity.


Asunto(s)
Antebrazo/cirugía , Trasplante de Piel/efectos adversos , Colgajos Quirúrgicos/efectos adversos , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Supervivencia de Injerto , Fuerza de la Mano , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Masculino , Nervio Mediano/fisiopatología , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/fisiopatología , Estudios Prospectivos , Nervio Radial/fisiopatología , Nervio Cubital/fisiopatología , Muñeca/fisiopatología
17.
Clin Pharmacol Ther ; 66(4): 374-9, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10546921

RESUMEN

BACKGROUND: Ketoconazole is a potent inhibitor of the cytochrome P450 3A4 enzyme. Reboxetine, a selective norepinephrine reuptake inhibitor, is metabolized by cytochrome P450 3A4. The potential interaction of reboxetine with this representative from the azole derivative class was examined. METHODS: Eleven healthy volunteers received (1) 4 mg reboxetine orally on the second day of a 5-day regimen of 200 mg ketoconazole once daily and (2) 4 mg reboxetine orally in a crossover design. Plasma concentrations of reboxetine enantiomers [R,R(-)-reboxetine and the more active S,S(+)-reboxetine] were measured by high-performance liquid chromatography-tandem mass spectrometry. Effects of ketoconazole on enantiomer pharmacokinetics were assessed by ANOVA. RESULTS: Ketoconazole increased R,R(-)-reboxetine and S,S(+)-reboxetine mean area under the plasma concentration-time curves (AUC) by 58% and 43%, respectively (P < .02). Oral clearance of both enantiomers was consequently decreased 34% and 24%, respectively, by ketoconazole (P < .005). Ketoconazole did not significantly affect maximal plasma concentrations (P > .1). Mean terminal half-life after administration of ketoconazole (21.5 hours and 18.9 hours) was significantly longer than after reboxetine alone (14.8 hours and 14.4 hours; P < or = .005). The AUC ratio for R,R(-)-reboxetine to S,S(+)-reboxetine was reduced by ketoconazole administration (2.76 after ketoconazole versus 2.39; P < .003). CONCLUSION: Ketoconazole decreases clearance of both reboxetine enantiomers. Although the adverse effect profile for reboxetine was not altered by ketoconazole, the results of this study suggest that caution should be used and that a reduction in reboxetine dose should be considered when the two are coadministered.


Asunto(s)
Antidepresivos/farmacocinética , Antifúngicos/farmacología , Cetoconazol/farmacología , Morfolinas/farmacocinética , Adulto , Análisis de Varianza , Antidepresivos/sangre , Antidepresivos/química , Área Bajo la Curva , Cromatografía Líquida de Alta Presión , Estudios Cruzados , Citocromo P-450 CYP3A , Sistema Enzimático del Citocromo P-450/metabolismo , Femenino , Humanos , Isomerismo , Masculino , Persona de Mediana Edad , Oxigenasas de Función Mixta/metabolismo , Morfolinas/sangre , Morfolinas/química , Reboxetina , Valores de Referencia
18.
Age Ageing ; 28(5): 458-62, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10529040

RESUMEN

BACKGROUND: The reason why elderly human hips tend to break in one of two anatomical regions is uncertain. Nutritional factors may affect the site of fracture. OBJECTIVE: To assess possible nutritional differences in patients with proximal femoral fractures. DESIGN: Prospective observational cohort study. SETTING: University teaching hospital. SUBJECTS: 119 consecutive patients over the age of 65 with a hip fracture admitted to the trauma wards in a single centre. METHODS: One researcher measured triceps, biceps and supra-iliac skinfold thickness, and mid upper arm circumference on admission and on the fifth post-operative day. Body mass index was calculated for each patient, and used to classify patients as severely, moderately or mildly malnourished, normal, overweight or obese. Logistic regression was used to determine the influence of various factors on fracture site. RESULTS: According to their body mass index, 31% of patients were classified as malnourished and 11% as severely malnourished. Patients with intracapsular fractures were significantly more malnourished than patients with trochanteric fractures (P < 0.008). Nutritional status was not related to post-operative complications. Ability to weigh a patient on the fifth post-operative day was the single most important prognostic indicator for complications. CONCLUSIONS: Patients with intracapsular fractures are more malnourished. Those with trochanteric fractures tend to be overweight.


Asunto(s)
Fracturas de Cadera/fisiopatología , Estado Nutricional/fisiología , Anciano , Anciano de 80 o más Años , Índice de Masa Corporal , Femenino , Humanos , Masculino , Trastornos Nutricionales , Estudios Prospectivos
19.
Mol Cell Biol ; 18(12): 7038-51, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9819391

RESUMEN

Membrane trafficking is regulated in part by small GTP-binding proteins of the ADP-ribosylation factor (Arf) family. Arf function depends on the controlled exchange and hydrolysis of GTP. We have purified and cloned two variants of a 130-kDa phosphatidylinositol 4, 5-biphosphate (PIP2)-dependent Arf1 GTPase-activating protein (GAP), which we call ASAP1a and ASAP1b. Both contain a pleckstrin homology (PH) domain, a zinc finger similar to that found in another Arf GAP, three ankyrin (ANK) repeats, a proline-rich region with alternative splicing and SH3 binding motifs, eight repeats of the sequence E/DLPPKP, and an SH3 domain. Together, the PH, zinc finger, and ANK repeat regions possess PIP2-dependent GAP activity on Arf1 and Arf5, less activity on Arf6, and no detectable activity on Arl2 in vitro. The cDNA for ASAP1 was independently identified in a screen for proteins that interact with the SH3 domain of the tyrosine kinase Src. ASAP1 associates in vitro with the SH3 domains of Src family members and with the Crk adapter protein. ASAP1 coprecipitates with Src from cell lysates and is phosphorylated on tyrosine residues in cells expressing activated Src. Both coimmunoprecipitation and tyrosine phosphorylation depend on the same proline-rich class II Src SH3 binding site required for in vitro association. By directly interacting with both Arfs and tyrosine kinases involved in regulating cell growth and cytoskeletal organization, ASAP1 could coordinate membrane remodeling events with these processes.


Asunto(s)
Proteínas Portadoras/metabolismo , GTP Fosfohidrolasas/metabolismo , Proteínas de Unión al GTP/metabolismo , Fosfatidilinositol 4,5-Difosfato/farmacología , Familia-src Quinasas/metabolismo , Factor 1 de Ribosilacion-ADP , Factores de Ribosilacion-ADP , Secuencia de Aminoácidos , Animales , Encéfalo/metabolismo , Bovinos , Activación Enzimática , Técnica del Anticuerpo Fluorescente , Datos de Secuencia Molecular , Fosforilación , Fosfotirosina/análisis , Unión Proteica , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-crk , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Dominios Homologos src/fisiología
20.
J Nucl Med ; 39(8): 1376-80, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9708511

RESUMEN

UNLABELLED: After the intracavitary administration of 131I-labeled monoclonal antibody for treatment of primary brain tumors after surgical resection, a persistent rim of 18F-fluorodeoxyglucose (FDG) accumulation surrounding the cavity can be observed on PET. This rim, although it accumulates more FDG than adjacent normal brain tissue, is not necessarily associated with tumor. In our study, we examine the characteristics of the rim that indicate persistent tumor and tumor progression. METHODS: Sequential PET studies obtained after treatment in 10 patients were reviewed and the results correlated with dosimetry and post-treatment histologic diagnoses. RESULTS: The rim of FDG accumulation was seen on the first post-treatment scan obtained 1-3 mo after therapy and persisted unchanged over the 2-26 mo follow-up period. Pathologically, the nonmalignant rim was associated with marked increase of macrophage infiltrates. Nodularity of the rim was associated with tumor. CONCLUSION: Our study demonstrates that a rim of FDG accumulation is seen after intracavitary administration of 131I-labeled monoclonal antibody therapy independent of the presence of malignant disease. Malignant recurrence is suggested by the development of new nodularity in the rim of FDG accumulation.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/radioterapia , Encéfalo/diagnóstico por imagen , Radioisótopos de Flúor , Fluorodesoxiglucosa F18 , Glioblastoma/diagnóstico por imagen , Glioblastoma/radioterapia , Radioisótopos de Yodo/uso terapéutico , Radioinmunoterapia , Radiofármacos , Tomografía Computarizada de Emisión , Adolescente , Adulto , Encéfalo/metabolismo , Neoplasias Encefálicas/metabolismo , Femenino , Fluorodesoxiglucosa F18/farmacocinética , Glioblastoma/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Radiofármacos/farmacocinética , Tenascina/inmunología
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