Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
BMC Health Serv Res ; 21(1): 1252, 2021 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-34798891

RESUMEN

BACKGROUND: Sepsis disproportionately affects children from socioeconomically disadvantaged families in low-resource settings, where care seeking may consume scarce family resources and lead to financial hardships. Those financial hardships may, in turn, contribute to late presentation or failure to seek care and result in high mortality during hospitalization and during the post discharge period, a period of increasingly recognized vulnerability. The purpose of this study is to explore the out-of-pocket costs related to sepsis hospitalizations and post-discharge care among children admitted with sepsis in Uganda. METHODS: This mixed-methods study was comprised of focus group discussions (FGD) with caregivers of children admitted for sepsis, which then informed a quantitative cross-sectional household survey to measure out-of-pocket costs of sepsis care both during initial admission and during the post-discharge period. All participants were families of children enrolled in a concurrent sepsis study. RESULTS: Three FGD with mothers (n = 20) and one FGD with fathers (n = 7) were conducted. Three primary themes that emerged included (1) financial losses, (2) time and productivity losses and (3) coping with costs. A subsequently developed cross-sectional survey was completed for 153 households of children discharged following admission for sepsis. The survey revealed a high cost of care for families attending both private and public facilities, although out-of-pocket cost were higher at private facilities. Half of those surveyed reported loss of income during hospitalization and a third sold household assets, most often livestock, to cover costs. Total mean out-of-pocket costs of hospital care and post-discharge care were 124.50 USD and 44.60 USD respectively for those seeking initial care at private facilities and 62.10 USD and 14.60 USD at public facilities, a high sum in a country with widespread poverty. CONCLUSIONS: This study reveals that families incur a substantial economic burden in accessing care for children with sepsis.


Asunto(s)
Gastos en Salud , Sepsis , Cuidados Posteriores , Niño , Estudios Transversales , Humanos , Alta del Paciente , Sepsis/terapia , Uganda/epidemiología
2.
Integr Biol (Camb) ; 10(7): 419-428, 2018 07 16.
Artículo en Inglés | MEDLINE | ID: mdl-29897363

RESUMEN

Improving fluorescent proteins through the use of directed evolution requires robust techniques for screening large libraries of genetic variants. Here we describe an effective and relatively low-cost system for screening libraries of fluorescent protein variants for improved photostability in the context of colonies on a Petri dish. Application of this system to the yellow fluorescent protein mCitrine, led to the development of Citrine2 with improved photostability and similar high fluorescent brightness. The photobleaching robot was constructed using a Lego Mindstorms Ev3 set and a xenon arc lamp, which together create even and high irradiance over an entire Petri dish through patterned illumination.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Luminiscentes/química , Fotoblanqueo , Robótica , Cristalografía por Rayos X , Escherichia coli , Células HeLa , Humanos , Luz , Modelos Biológicos , Mutación , Fotoquímica , Plásmidos/metabolismo
3.
Matern Child Health J ; 20(10): 2209-15, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27299903

RESUMEN

Introduction The prevalence of ethanol use in many Sub-Saharan African countries is high, but little research exists on use during pregnancy. The objective of this study was to assess the prevalence and predictors of ethanol use among pregnant women in Southwestern Uganda. Methods This descriptive, cross-sectional study was conducted in the maternity ward at Mbarara Regional Referral Hospital (MRRH). All pregnant women giving birth at MRRH between September 23, 2013 and November 23, 2013 were eligible for enrollment. The primary outcome was the proportion of women with ethanol use during pregnancy as determined by self-report. Secondary outcomes included the proportion with positive fatty acid ethyl ester (FAEE) results (indicating ethanol use) and positive TWEAK questionnaire results (indicating possible problem drinking). Predictors of ethanol use were assessed and stratified by patterns of ethanol intake. Results Overall, 505 mother-child dyads enrolled in the study. The proportion of women who reported any ethanol use during pregnancy was 16 % (n = 81, 95 % CI 13-19 %) and the prevalence of heavy drinking 6.3 % (n = 32, 95 % CI 3.8-7.9 %). The strongest predictor of use during pregnancy was pre-pregnancy use, with maternal education as a protective factor. Few neonates (n = 11, 2 %) tested positive for FAEE > 2.00 nmol/g in meconium. The TWEAK questionnaire captured 75 % of women who reported moderate/heavy drinking and aligned more with self-reported ethanol use than meconium results. Conclusions The substantial prevalence and clear predictors of ethanol use suggest that legislative action and educational interventions to increase awareness of potential harms could assist in efforts to decrease use during pregnancy in Southwestern Uganda.


Asunto(s)
Consumo de Bebidas Alcohólicas/efectos adversos , Alcoholismo/epidemiología , Trastornos del Espectro Alcohólico Fetal/epidemiología , Mujeres Embarazadas , Adulto , Consumo de Bebidas Alcohólicas/etnología , Consumo de Bebidas Alcohólicas/metabolismo , Estudios Transversales , Femenino , Humanos , Intercambio Materno-Fetal , Meconio/química , Embarazo , Mujeres Embarazadas/etnología , Prevalencia , Factores Socioeconómicos , Encuestas y Cuestionarios , Uganda/epidemiología
4.
Afr Health Sci ; 16(4): 883-891, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28479878

RESUMEN

BACKGROUND: Out-of-hospital death among children living in resource poor settings occurs frequently. Little is known about the location and circumstances of child death following a hospital discharge. OBJECTIVES: This study aimed to understand the context surrounding out-of-hospital deaths and the barriers to accessing timely care for Ugandan children recently discharged from the hospital. METHODS: This was a mixed-methods sub-study within a larger cohort study of post-discharge mortality conducted in the Southwestern region of Uganda. Children admitted with an infectious illness were eligible for enrollment in the cohort study, and then followed for six months after discharge. Caregivers of children who died outside of the hospital during the six month post-discharge period were eligible to participate in this sub-study. Qualitative interviews and univariate logistic regression were conducted to determine predictors of out-of-hospital deaths. RESULTS: Of 1,242 children discharged, 61 died during the six month post-discharge period, with most (n=40, 66%) dying outside of a hospital. Incremental increases in maternal education were associated with lower odds of out-of-hospital death compared to hospital death (OR: 0.38, 95% CI: 0.19 - 0.81). The qualitative analysis identified health seeking behaviors and common barriers within the post-discharge period which delayed care seeking prior to death. For recently discharged children, caregivers often expressed hesitancy to seek care following a recent episode of hospitalization. CONCLUSION: Mortality following discharge often occurs outside of a hospital context. In addition to resource limitations, the health knowledge and perceptions of caregivers can be influential to timely access to care. Interventions to decrease child mortality must consider barriers to health seeking among children following hospital discharge.


Asunto(s)
Mortalidad del Niño , Enfermedades Transmisibles/mortalidad , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Mortalidad Infantil , Alta del Paciente/estadística & datos numéricos , Cuidadores/psicología , Preescolar , Escolaridad , Femenino , Humanos , Lactante , Tiempo de Internación , Modelos Logísticos , Masculino , Aceptación de la Atención de Salud/psicología , Factores de Tiempo , Uganda/epidemiología , Abastecimiento de Agua
5.
BMJ Open ; 5(11): e009449, 2015 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-26608641

RESUMEN

OBJECTIVES: To derive a model of paediatric postdischarge mortality following acute infectious illness. DESIGN: Prospective cohort study. SETTING: 2 hospitals in South-western Uganda. PARTICIPANTS: 1307 children of 6 months to 5 years of age were admitted with a proven or suspected infection. 1242 children were discharged alive and followed up 6 months following discharge. The 6-month follow-up rate was 98.3%. INTERVENTIONS: None. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was postdischarge mortality within 6 months following the initial hospital discharge. RESULTS: 64 children died during admission (5.0%) and 61 died within 6 months of discharge (4.9%). Of those who died following discharge, 31 (51%) occurred within the first 30 days. The final adjusted model for the prediction of postdischarge mortality included the variables mid-upper arm circumference (OR 0.95, 95% CI 0.94 to 0.97, per 1 mm increase), time since last hospitalisation (OR 0.76, 95% CI 0.61 to 0.93, for each increased period of no hospitalisation), oxygen saturation (OR 0.96, 95% CI 0.93 to 0·99, per 1% increase), abnormal Blantyre Coma Scale score (OR 2.39, 95% CI 1·18 to 4.83), and HIV-positive status (OR 2.98, 95% CI 1.36 to 6.53). This model produced a receiver operating characteristic curve with an area under the curve of 0.82. With sensitivity of 80%, our model had a specificity of 66%. Approximately 35% of children would be identified as high risk (11.1% mortality risk) and the remaining would be classified as low risk (1.4% mortality risk), in a similar cohort. CONCLUSIONS: Mortality following discharge is a poorly recognised contributor to child mortality. Identification of at-risk children is critical in developing postdischarge interventions. A simple prediction tool that uses 5 easily collected variables can be used to identify children at high risk of death after discharge. Improved discharge planning and care could be provided for high-risk children.


Asunto(s)
Mortalidad del Niño , Infecciones/mortalidad , Modelos Biológicos , Alta del Paciente , Enfermedad Aguda , Área Bajo la Curva , Preescolar , Femenino , Hospitalización , Humanos , Lactante , Masculino , Estudios Prospectivos , Curva ROC , Factores de Riesgo , Uganda/epidemiología
6.
Bioinspir Biomim ; 9(4): 044001, 2014 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-25378146

RESUMEN

Inspired by the intermolecular cross-linking of mussel foot proteins and their adhesive properties, tyrosinase has been used to modify recombinant silicatein. DOPA/DOPAquinone-mediated cross-linking and interfacial interactions enhanced both self-assembly of silicatein building blocks and templating of core-shell silica spheres, resulting in fluorescent biomimetic silicatein-silica hybrid mesofibers.


Asunto(s)
Materiales Biomiméticos/síntesis química , Catepsinas/química , Colorantes Fluorescentes/química , Monofenol Monooxigenasa/química , Nanosferas/química , Poríferos/química , Dióxido de Silicio/química , Animales , Ensayo de Materiales , Nanoporos/ultraestructura , Nanosferas/ultraestructura
7.
J Cell Biochem ; 113(10): 3197-206, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22615001

RESUMEN

It has been shown that inorganic monomeric and polymeric silica/silicate, in the presence of the biomineralization cocktail, increases the expression of osteoprotegerin (OPG) in osteogenic SaOS-2 sarcoma cells in vitro. In contrast, silicate does not affect the steady-state gene expression level of the osteoclastogenic ligand receptor activator of NF-κB ligand (RANKL). In turn it can be expected that the concentration ratio of the mediators OPG/RANKL increases in the presence of silicate. In addition, silicate enhances the growth potential of SaOS-2 cells in vitro, while it causes no effect on RAW 264.7 cells within a concentration range of 10-100 µM. Applying a co-cultivation assay system, using SaOS-2 cells and RAW 264.7 cells, it is shown that in the presence of 10 µM silicate the number of RAW 264.7 cells in general, and the number of TRAP(+) RAW 264.7 cells in particular markedly decreases. The SaOS-2 cells retain their capacity of differential gene expression of OPG and RANKL in favor of OPG after exposure to silicate. It is concluded that after exposure of the cells to silicate a factor(s) is released from SaOS-2 cells that causes a significant inhibition of osteoclastogenesis of RAW 264.7 cells. It is assumed that it is an increased secretion of the cytokine OPG that is primarily involved in the reduction of the osteoclastogenesis of the RAW 264.7 cells. It is proposed that silicate might have the potential to stimulate osteogenesis in vivo and perhaps to ameliorate osteoporotic disorders.


Asunto(s)
Comunicación Celular , Diferenciación Celular , Osteoblastos/efectos de los fármacos , Osteoclastos/efectos de los fármacos , Silicatos/farmacología , Fosfatasa Ácida/genética , Fosfatasa Ácida/metabolismo , Animales , Conservadores de la Densidad Ósea/farmacología , Recuento de Células , Línea Celular , Proliferación Celular , Supervivencia Celular , Técnicas de Cocultivo , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Osteogénesis , Ligando RANK/genética , Ligando RANK/metabolismo , Fosfatasa Ácida Tartratorresistente
8.
Cell Death Differ ; 18(2): 201-13, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20651742

RESUMEN

Survivin orchestrates intracellular pathways during cell division and apoptosis. Its central function as mitotic regulator and inhibitor of cell death has major implications for tumor cell proliferation. Analyses in early-branching Metazoa so far propose an exclusive role of survivin as a chromosomal passenger protein, whereas only later during evolution a complementary antiapoptotic function might have arisen, concurrent with increased organismal complexity. To lift the veil on the ancestral function(s) of this key regulator, a survivin-like protein (SURVL) of one of the earliest-branching metazoan taxa was identified and functionally characterized. SURVL of the sponge Suberites domuncula shares considerable similarities with its metazoan homologs, ranging from conserved exon/intron structure to presence of protein-interaction domains. Whereas sponge tissue shows a low steady-state level, SURVL expression was significantly upregulated in rapidly proliferating primmorph cells. In addition, challenge of tissue and primmorphs with heavy metal or lipopeptide stimulated SURVL expression, concurrent with the expression of a newly discovered caspase. Complementary functional analyses in transfected HEK-293 cells revealed that heterologous expression of a SURVL-EFGP fusion not only promotes proliferation but also enhances resistance to cadmium-induced cell death. Taken together, these results suggest both a deep evolutionary conserved dual role of survivin and an equally conserved central position in the interconnected pathways of cell cycle and apoptosis.


Asunto(s)
Apoptosis , Ciclo Celular , Proteínas Inhibidoras de la Apoptosis/metabolismo , Suberites/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Cadmio/toxicidad , Caspasas/química , Caspasas/genética , Caspasas/metabolismo , División Celular , Línea Celular , Humanos , Proteínas Inhibidoras de la Apoptosis/química , Proteínas Inhibidoras de la Apoptosis/fisiología , Lipopéptidos/farmacología , Datos de Secuencia Molecular , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Alineación de Secuencia , Suberites/enzimología , Suberites/genética , Transfección
9.
Mol Biol Evol ; 27(9): 1983-7, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20378579

RESUMEN

Despite expanding data sets and advances in phylogenomic methods, deep-level metazoan relationships remain highly controversial. Recent phylogenomic analyses depart from classical concepts in recovering ctenophores as the earliest branching metazoan taxon and propose a sister-group relationship between sponges and cnidarians (e.g., Dunn CW, Hejnol A, Matus DQ, et al. (18 co-authors). 2008. Broad phylogenomic sampling improves resolution of the animal tree of life. Nature 452:745-749). Here, we argue that these results are artifacts stemming from insufficient taxon sampling and long-branch attraction (LBA). By increasing taxon sampling from previously unsampled nonbilaterians and using an identical gene set to that reported by Dunn et al., we recover monophyletic Porifera as the sister group to all other Metazoa. This suggests that the basal position of the fast-evolving Ctenophora proposed by Dunn et al. was due to LBA and that broad taxon sampling is of fundamental importance to metazoan phylogenomic analyses. Additionally, saturation in the Dunn et al. character set is comparatively high, possibly contributing to the poor support for some nonbilaterian nodes.


Asunto(s)
Filogenia , Animales , Ctenóforos/clasificación , Ctenóforos/genética , Familia de Multigenes/genética , Poríferos/clasificación , Poríferos/genética
10.
Praxis (Bern 1994) ; 98(9): 493-6, 2009 Apr 29.
Artículo en Alemán | MEDLINE | ID: mdl-19404909

RESUMEN

We report the case of a 84 year old patient who developed a syndrome of inappropriate antidiuretic hormone secretion (SIADH) with severe hyponatremia in the context of a localized herpes zoster L1/2. This is a rare but known complication of localized varizella zoster infection. Under water restriction and salt administration the hyponatremia was corrected slowly. One month after hospital discharge the patient showed a normal sodium value without diet.


Asunto(s)
Herpes Zóster/diagnóstico , Hiponatremia/etiología , Síndrome de Secreción Inadecuada de ADH/etiología , Anciano de 80 o más Años , Demencia/etiología , Diagnóstico Diferencial , Femenino , Herpes Zóster/complicaciones , Humanos , Hiponatremia/terapia , Síndrome de Secreción Inadecuada de ADH/terapia
11.
Cell Mol Life Sci ; 66(3): 537-52, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19151920

RESUMEN

Two classes of sponges (animal phylum Porifera) possess a siliceous skeleton which is composed of spicules. Studying the optical fiber-mechanical properties of large spicules from hexactinellid sponges (> 5 cm) it was demonstrated that they are effective light-collecting optical fibers. Here, we report that the demosponge Suberites domuncula is provided with a biosensor system composed of the (organic) light producing luciferase and the (inorganic) light transducing silica spicules. The light transmission feature of these smaller spicules (200 microm) has been demonstrated and the ability of sponge tissue to generate light has been proven. Screening for a luciferase gene in S. domuncula was successful; the recombinant luciferase was prepared and shown to be bioactive. The luciferase protein is abundantly present in the close neighborhood of the spicules. The expression of the luciferase gene is under the control of light.


Asunto(s)
Técnicas Biosensibles , Luz , Luciferasas/metabolismo , Poríferos , Dióxido de Silicio/metabolismo , Secuencia de Aminoácidos , Animales , Luciferasas/clasificación , Luciferasas/genética , Proteínas Luminiscentes/clasificación , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Filogenia , Poríferos/anatomía & histología , Poríferos/metabolismo , Alineación de Secuencia
13.
J Intern Med ; 260(4): 350-62, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16961672

RESUMEN

OBJECTIVE: To quantitatively pool findings from observational studies on the risk of fracture outcomes associated with exposure to five antihypertensive drug classes: angiotensin-converting enzyme (ACE) inhibitors, diuretics (in particular thiazide diuretics), beta-blockers, calcium-channel blockers and alpha-blockers. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Publications listed in the MEDLINE, EMBASE and LILACS databases, the ISI proceedings, and bibliographies of retrieved articles. Sources were searched from the earliest possible dates through December 2005. REVIEW METHODS: We included case-control and cohort studies presenting relative risks and confidence intervals (CIs) for the association between exposure to antihypertensive agents and fracture outcomes. Data were extracted onto a standardized computer worksheet. Study quality was assessed using a 10-point questionnaire specific to case-control or cohort study design. RESULTS: Fifty-four studies were identified. Pooled estimates were computed using the software HEpiMA. The pooled relative risk (RR) of any fracture with use of thiazide diuretics was 0.86 (95% CI 0.81-0.92) and 1.14 (95% CI 0.84-1.54) with use of nonthiazide diuretics. There was a statistically significant reduction of any fracture with use of beta-blockers, (RR 0.86, 95% CI 0.70-0.98). The one study with ACE inhibitor data showed protection (RR 0.81, 95% CI 0.73-0.89). No significant associations were found between fractures and exposure to alpha-blockers or calcium-channel blockers. CONCLUSIONS: Thiazide diuretics and beta-blockers appear to lower the risk of fractures in older adults. However, these agents cannot be recommended as preventive therapies for fractures until data from randomized controlled trials have established their efficacy. Patients who use these inexpensive drugs as treatments for hypertension may also benefit from a reduction in fracture risk.


Asunto(s)
Antihipertensivos/uso terapéutico , Fracturas Óseas/prevención & control , Antagonistas Adrenérgicos alfa/uso terapéutico , Antagonistas Adrenérgicos beta/uso terapéutico , Adulto , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Bloqueadores de los Canales de Calcio/uso terapéutico , Diuréticos/uso terapéutico , Femenino , Humanos , Hipertensión/tratamiento farmacológico , Masculino , Pronóstico , Riesgo , Inhibidores de los Simportadores del Cloruro de Sodio/uso terapéutico
14.
Z Gerontol Geriatr ; 37(3): 190-9, 2004 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-15224239

RESUMEN

Sponges (phylum Porifera) represent the oldest metazoan taxon. Through a variety of molecular biological methods the existence of elaborated mechanisms such as programmed cell death was established in those organisms that are regarded today as living fossils. Among the apoptotic proteins identified in sponges are the key molecules of apoptotic pathways, effectors (caspases, death domain proteins) and regulators (Bcl-2 homologues) of programmed cell death. Furthermore, when introduced in vertebrate cells one sponge anti-apoptotic Bcl-2 homologue displayed its pro-survival function in the heterologous system, confirming the conserved character of apoptotic cell death. Comparing apoptotic elements of both the most ancient and the most recent of all metazoans might elucidate the evolution of programmed cell death and processes involved, such as aging.


Asunto(s)
Envejecimiento/fisiología , Apoptosis/fisiología , Caspasas/metabolismo , Poríferos/fisiología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Animales , Evolución Molecular , Invertebrados , Poríferos/citología , Receptores del Factor de Necrosis Tumoral/metabolismo
15.
Prog Mol Subcell Biol ; 34: 103-43, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-14979666

RESUMEN

Porifera (sponges) are now well accepted as the phylum which branched off first from the common ancestor of all metazoans, the Urmetazoa. The transition to the Metazoa became possible because during this phase, cell-cell as well as cell-matrix adhesion molecules evolved which allowed the formation of a colonial stage of animals. The next prerequisite for the evolution to the Urmetazoa was the establishment of an effective immune system which, flanked by apoptosis, allowed the formation of a first level of individuation. In sponges (with the model Suberites domuncula and Geodia cydonium), the main mediators of the immune responses are the chemokines. Since sponges lack a vascular system and consequently blood cells (in the narrow sense), we have used the term chemokines (in a broad sense) to highlight that the complex network of intercellular mediators initiates besides differentiation processes also cell movement. In the present review, the cDNAs encoding the following chemokines were described and the roles of their deduced proteins during self-self and nonself recognition outlined: the allograft inflammatory factor, the glutathione peroxidase, the endothelial-monocyte-activating polypeptide, the pre-B-cell colony-enhancing factor and the myotrophin as well as an enzyme, the (2-5)A synthetase, which is involved in cytokine response in vertebrates. A further step required to reach the evolutionary step of the integrated stage of the Urmetazoa was the acquisition of a stem cell system. In this review, first markers for stem cells (mesenchymal stem cell-like protein) as well as for chemokines involved in the maintenance of stem cells (noggin and glia maturation factor) are described at the molecular level, and a first functional analysis is approached. Taken together, it is outlined that the chemokine network was essential for the establishment of metazoans, which evolved approximately 600 to 800 million years ago.


Asunto(s)
Quimiocinas/fisiología , Poríferos/crecimiento & desarrollo , Poríferos/inmunología , 2',5'-Oligoadenilato Sintetasa/genética , 2',5'-Oligoadenilato Sintetasa/fisiología , Secuencia de Aminoácidos , Animales , Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/fisiología , Quimiocinas/genética , Citocinas/genética , Citocinas/fisiología , Glutatión Peroxidasa/genética , Glutatión Peroxidasa/fisiología , Modelos Biológicos , Datos de Secuencia Molecular , Filogenia , Poríferos/citología , Poríferos/genética , Homología de Secuencia de Aminoácido , Células Madre/citología , Células Madre/inmunología , Inmunología del Trasplante
16.
Cell Death Differ ; 8(9): 887-98, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11526444

RESUMEN

It is established that sponges, the phylogenetically oldest still extant phylum of Metazoa, possess key molecules of the apoptotic pathways, that is members from the Bcl-2 family and a pro-apoptotic molecule with death domains. Here we report on transfection studies of human cells with a sponge gene, GCBHP2. Sponge tissue was exposed to heat shock and tributyltin, which caused an upregulation of gene expression of GCBHP2. The cDNA GCBHP2 was introduced into human HEK-293 cells and mouse NIH-3T3 cells; the stable transfection was confirmed by the identification of the transcripts, by Western blotting as well as by immunofluorescence using antibodies raised against the recombinant polypeptide. HEK-293 cells, transfected with GCBHP2, showed high resistance to serum starvation and tributyltin treatment, compared to mock-transfected cells. In contrast to mock-transfected cells, GCBHP2-transfected cells activated caspase-3 to a lower extent. Thus, sponges contain gene(s) involved in apoptotic pathway(s) displaying their function also in human cells.


Asunto(s)
Supervivencia Celular , Poríferos , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Secuencia de Aminoácidos , Animales , Anticuerpos/inmunología , Apoptosis/efectos de los fármacos , Caspasa 3 , Caspasas/metabolismo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Clonación Molecular , Resistencia a Medicamentos , Activación Enzimática/efectos de los fármacos , Respuesta al Choque Térmico/efectos de los fármacos , Respuesta al Choque Térmico/genética , Calor , Humanos , Ratones , Datos de Secuencia Molecular , Filogenia , Poríferos/citología , Poríferos/efectos de los fármacos , Poríferos/genética , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas c-bcl-2/química , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/inmunología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Compuestos de Trialquiltina/farmacología , Regulación hacia Arriba/efectos de los fármacos
17.
J Mol Evol ; 50(6): 520-31, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10835482

RESUMEN

Cells from metazoan organisms are eliminated in a variety of physiological and pathophysiological processes by apoptosis. In this report, we describe the cloning and characterization of molecules from the marine sponges Geodia cydonium and Suberites domuncula, whose domains show a high similarity to those that are found in molecules of the vertebrate Bcl-2 superfamily and of the death receptors. The Bcl-2 proteins contain up to four Bcl-2 homology regions (BH). Two Bcl-2-related molecules have been identified from sponges that are provided with two of those regions, BH1 and BH2, and are termed Bcl-2 homology proteins (BHP). The G. cydonium molecule, BHP1_GC, has a putative size of 28,164, while the related sequence from S. domuncula, BHP1_SD, has a M(r) of 24,187. Phylogenetic analyses of the entire two sponge BHPs revealed a high similarity to members of the mammalian Bcl-2 superfamilies and to the Caenorhabditis elegans Ced-9. When the two domains, BH1 and BH2, are analyzed separately, again the highest similarity was found to the members of the Bcl-2 superfamily, but a clearly lower relationship to the C. elegans BH1 and BH2 domains in Ced-9. In unrooted phylogenetic trees the sponge BH1 and BH2 are grouped among the mammalian sequences and are only distantly related to the C. elegans BH domains. The analysis of the gene structure of the G. cydonium BHP showed that the single intron present is located within the BH2 domain at the same position as in C. elegans and rat Bcl-x(L). In addition, a sponge molecule comprising two death domains has been characterized from G. cydonium. The two death domains of the potential proapoptotic molecule GC_DD2, M(r) 24,970, share a high similarity with the Fas-FADD/MORT1 domains. A death domain-containing molecule has not been identified in the C. elegans genome. The phylogenetic analysis revealed that the sponge domain originated from an ankyrin building block from which the mammalian Fas-FADD/MORT1 evolved. It is suggested that the apoptotic pathways that involve members of the Bcl-2 superfamily and of the death receptors are already present in the lowest metazoan phylum, the Porifera.


Asunto(s)
Apoptosis/genética , Evolución Molecular , Filogenia , Poríferos/genética , Proteínas Proto-Oncogénicas c-bcl-2/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Humanos , Datos de Secuencia Molecular , Péptidos/química , Péptidos/genética , Poríferos/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/química , Homología de Secuencia de Aminoácido
18.
Cell Death Differ ; 7(5): 461-9, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10800079

RESUMEN

Sponges (Porifera) are a classical model to study the events during tissue transplantation. Applying the 'insertion technique' autografts from the marine sponge Geodia cydonium fuse within 5 days. In contrast, allografts are rejected and destroyed. Here we show that during allograft rejection the cells in the grafts undergo apoptosis; 5 days after transplantation 46% of the cells show signs of apoptosis. In a previous study it was shown that during this process a tumor necrosis factor-like molecule is induced in allo- and xenografts. Molecules grouped to the superfamily of tumor necrosis factor receptors and a series of associated adapter molecules contain the characteristic death domain. Therefore, we screened for a cDNA encoding such a domain. Here we report on the first invertebrate molecule from Geodia cydonium comprising a death domain. The potential proapoptotic molecule DD2, with a calculated Mr of 24 970, possesses in contrast to all known mammalian death domain-containing proteins two such domains with highest similarity to the death domain present in human Fas/APO-1. The expression of this gene is not detectable in control tissue but strongly upregulated in allografts; only very low expression is seen in autografts. Parallel with the increase of the expression of the potential proapoptotic molecule DD2 in allografts the level of LTB4 drastically increases from 2.5 pg/mg of protein (controls) to 389 pg LTB4/mg during a period of 5 days after transplantation; the level of LTB4 in autografts does not change. Very likely in response to inflammatory reactions the LTB4 metabolizing enzyme LTB4 12-hydroxy-dehydrogenase is expressed both in auto- and allografts. These results demonstrate that sponges are provided with apoptotic pathways, similar to those present in deuterostomes and apparently absent in protostomes, which are composed of molecules comprising a death domain. In addition, it is suggested that in sponges LTB4 is one metabolite which is involved in the initiation of apoptosis. It is postulated that the potential proapoptotic effect of LTB4 is prevented in auto-grafts by the expression of the LTB4 12-hydroxy-dehydrogenase.


Asunto(s)
Apoptosis/fisiología , Rechazo de Injerto/inmunología , Rechazo de Injerto/metabolismo , Leucotrieno B4/biosíntesis , Péptidos/metabolismo , Poríferos/inmunología , Poríferos/metabolismo , Oxidorreductasas de Alcohol/genética , Oxidorreductasas de Alcohol/metabolismo , Secuencia de Aminoácidos , Animales , Apoptosis/inmunología , Clonación Molecular , Expresión Génica , Humanos , Datos de Secuencia Molecular , Péptidos/genética , Poríferos/citología , Homología de Secuencia de Aminoácido , Trasplante Autólogo , Trasplante Homólogo
19.
J Exp Mar Biol Ecol ; 245(2): 265-276, 2000 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-10699214

RESUMEN

Previously it was found that the expression of selected heat-shock proteins is upregulated in corals after exposure to elevated temperature. We published that HSPs are suitable markers in sponges to monitor the degree of environmental stress on these animals. In the present study the heat-shock proteins (HSPs) with a molecular weight of 90 kDa have been selected to prove their potential usefulness as biomarkers under controlled laboratory conditions and in the field. The studies have been performed with the octocoral Dendronephthya klunzingeri4.5-fold higher steady-state level of the respective mRNA. Also animals taken from stressed locations in the field showed an increased expression. The amount of HSP90 protein in D. klunzingeri was found to be strongly increased under thermal stress, or exposure to polychlorinated biphenyl (congener 118), but not after treatment with cadmium. Field studies revealed that samples taken from a nonstressed area have a low level of HSP90, but those collected from locations at which the corals are under physical stress (sedimentation through landfilling) show a high expression of HSP90. It is concluded that the chaperone HSP90 might become a suitable biomarker to monitor environmental stress on corals.

20.
FEBS Lett ; 462(1-2): 12-8, 1999 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-10580083

RESUMEN

In vertebrates cytokines mediate innate (natural) immunity and protect them against viral infections. The cytokine interferon causes the induction of the (2'-5')oligoadenylate synthetase [(2-5)A synthetase], whose product, (2'-5')oligoadenylate, activates the endoribonuclease L which in turn degrades (viral) RNA. Three isoforms of (2-5)A synthetases exist, form I (40-46 kDa), form II (69 kDa), and form III (100 kDa). Until now (2-5)A synthetases have only been cloned from birds and mammals. Here we describe the cloning of the first putative invertebrate (2-5)A synthetase from the marine sponge Geodia cydonium. The deduced amino acid sequence shows signatures characteristic for (2-5)A synthetases of form I. Phylogenetic analysis of the putative sponge (2-5)A synthetase indicates that it diverged first from a common ancestor of the hitherto known members of (vertebrate) (2-5)A synthetases I, (2-5)A synthetases II and III. Moreover, it is suggested that the (2-5)A synthetases II and III evolved from this common ancestor (very likely) by gene duplication. Together with earlier results on the existence of the (2'-5')oligoadenylates in G. cydonium, the data presented here demonstrate that also invertebrates, here sponges, are provided with the (2-5)A system. At present, it is assumed that this system might be involved in growth control, including control of apoptosis, and acquired its additional function in innate immune response in evolutionarily younger animals, in vertebrates.


Asunto(s)
2',5'-Oligoadenilato Sintetasa/genética , Interferones/farmacología , Poríferos/enzimología , 2',5'-Oligoadenilato Sintetasa/biosíntesis , 2',5'-Oligoadenilato Sintetasa/clasificación , 2',5'-Oligoadenilato Sintetasa/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Clonación de Organismos , ADN Complementario/análisis , Inducción Enzimática , Evolución Molecular , Datos de Secuencia Molecular , Filogenia , Homología de Secuencia de Aminoácido
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...