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1.
J Appl Microbiol ; 126(6): 1910-1922, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30925006

RESUMEN

AIMS: The aim was to determine the survival and persistence of Escherichia coli in soil amended with compost from different manure sources. METHOD AND RESULTS: Complex interactions of abiotic and biotic factors on E. coli survival were characterized in field experiment plots receiving randomly assigned compost treatments: dairy windrow, dairy vermicompost, poultry windrow or no compost. Biomass, activity and function of indigenous microbial communities in the composts and soils were measured concurrently to determine whether mechanisms of compost were driven by biotic or abiotic properties. E. coli persisted in compost containing poultry amendments but not in composts containing dairy or no amendments. Poultry compost contained more NH4 -N and a distinct microbial community compared to dairy and no compost treatments. A laboratory experiment performed on compost extracts suggested that E. coli survived better in extracts devoid of indigenous microbes as long as bioavailable nutrients were plentiful. CONCLUSIONS: Dairy-based composts are less likely to support E. coli survival than poultry-based composts. SIGNIFICANCE AND IMPACT OF THE STUDY: Results aid in risk assessment of the use of different types of manure-based compost and soil amendments in fruit and vegetable production by elucidating the roles of nutrient and microbial community composition on survival of E. coli in amended field soils.


Asunto(s)
Compostaje/métodos , Enterobacteriaceae/fisiología , Estiércol/microbiología , Microbiología del Suelo , Spinacia oleracea/crecimiento & desarrollo , Animales , Bovinos , Enterobacteriaceae/crecimiento & desarrollo , Escherichia coli/crecimiento & desarrollo , Escherichia coli/fisiología , Viabilidad Microbiana , Nutrientes/química , Aves de Corral , Suelo/química
2.
Mucosal Immunol ; 7(2): 239-48, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23778354

RESUMEN

Immunity to Nippostrongylus brasiliensis reinfection requires pulmonary CD4⁺ T-cell responses. We examined whether secondary lymphoid recruited or pre-existing lung CD4⁺ T-cell populations coordinated this immunity. To do this, we blocked T-cell egress from lymph nodes using Fingolimod (FTY720). This impaired host ability to resolve a primary infection but did not change effectiveness of recall immunity. Associated with this effective recall immunity was the expansion and T helper type 2 polarization of a pre-existing pulmonary CD4⁺ T-cell population. LTßR-Ig (lymphotoxin beta-receptor fusion protein)-mediated disruption of stromal cell organization of immune cells did not disrupt this recall immunity, suggesting that protection was mediated by a pulmonary interstitial residing CD4⁺ T-cell population. Adoptive transfer of N. brasiliensis-experienced pulmonary CD4⁺ T cells from FTY720-treated wild-type or T-cell interleukin (IL)-4Rα-deficient mice demonstrated protection to be IL-4Rα dependent. These results show that pre-existing CD4⁺ T cells can drive effective recall immunity to N. brasiliensis infection independently of T-cell recruitment from secondary lymphoid organs.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Memoria Inmunológica , Subunidad alfa del Receptor de Interleucina-4/metabolismo , Pulmón/inmunología , Pulmón/metabolismo , Nippostrongylus/inmunología , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/metabolismo , Animales , Linfocitos T CD4-Positivos/metabolismo , Movimiento Celular/genética , Movimiento Celular/inmunología , Modelos Animales de Enfermedad , Expresión Génica , Subunidad alfa del Receptor de Interleucina-4/genética , Pulmón/parasitología , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Ratones , Ratones Noqueados , Infecciones por Strongylida/genética , Infecciones por Strongylida/parasitología
3.
Mucosal Immunol ; 4(1): 83-92, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20737001

RESUMEN

Nippostrongylus brasiliensis infections generate pulmonary pathologies that can be associated with strong T(H)2 polarization of the host's immune response. We present data demonstrating N. brasiliensis-driven airway mucus production to be dependent on smooth muscle cell interleukin 4 receptor-α (IL-4Rα) responsiveness. At days 7 and 10 post infection (PI), significant airway mucus production was found in IL-4Rα(-/lox) control mice, whereas global knockout (IL-4Rα(-/-)) and smooth muscle-specific IL-4Rα-deficient mice (SM-MHC(Cre) IL-4Rα(-/lox)) showed reduced airway mucus responses. Furthermore, interleukin (IL)-13 and IL-5 cytokine production in SM-MHC(Cre) IL-4Rα(-/lox) mice was impaired along with a transient reduction in T-cell numbers in the lung. In vitro treatment of smooth muscle cells with secreted N. brasiliensis excretory-secretory antigen (NES) induced IL-6 production. Decreased protein kinase C (PKC)-dependent smooth muscle cell proliferation associated with cell cycle arrest was found in cells stimulated with NES. Together, these data demonstrate that both IL-4Rα and NES-driven responses by smooth muscle cells make important contributions in initiating T(H)2 responses against N. brasiliensis infections.


Asunto(s)
Subunidad alfa del Receptor de Interleucina-4/inmunología , Enfermedades Pulmonares Parasitarias/inmunología , Miocitos del Músculo Liso/inmunología , Miocitos del Músculo Liso/metabolismo , Nippostrongylus/inmunología , Infecciones por Strongylida/inmunología , Células Th2/inmunología , Animales , Ciclo Celular/genética , Citometría de Flujo , Interleucina-13/biosíntesis , Interleucina-13/inmunología , Subunidad alfa del Receptor de Interleucina-4/genética , Subunidad alfa del Receptor de Interleucina-4/metabolismo , Interleucina-5/biosíntesis , Interleucina-5/inmunología , Interleucina-6/biosíntesis , Interleucina-6/inmunología , Enfermedades Pulmonares Parasitarias/patología , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Moco/metabolismo , Nippostrongylus/patogenicidad , Proteína Quinasa C/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Infecciones por Strongylida/patología
4.
J Affect Disord ; 112(1-3): 36-49, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18835043

RESUMEN

OBJECTIVES: To evaluate the efficacy and safety of aripiprazole as acute and maintenance of effect monotherapy for acute bipolar mania. METHODS: Patients with acute bipolar I mania (DSM-IV-TR: YMRS > or =20), manic or mixed (with or without psychotic features) were randomized to double-blind aripiprazole (15-30 mg/day; n=155), placebo (n=165) or lithium (900-1500 mg/day; n=160) (1:1:1) for 3 weeks. Aripiprazole- and lithium-treated patients remained on blinded treatment for 9 additional weeks. The primary outcome was the mean change from baseline in YMRS Total score (LOCF) to Week 3. Secondary outcomes included the mean change from baseline in YMRS Total score (LOCF) at all other timepoints up to Week 12. RESULTS: Aripiprazole demonstrated significantly greater improvement than placebo in mean YMRS Total score from baseline to Day 2 (-4.3 vs.-2.8; p=0.003), and up to Week 3 (-12.6 vs. -9.0; p<0.001). Significant improvement in YMRS Total score was also seen with lithium versus placebo at Week 3 (-12.0 vs. -9.0; p=0.005). Improvements in YMRS Total score were maintained to Week 12 for aripiprazole (-14.5) and lithium (-12.7). Response rates at Week 3 were significantly higher with aripiprazole (46.8%) and lithium (45.8%) than placebo (34.4%; both p<0.05, LOCF); increasing to Week 12 with aripiprazole (56.5%) and lithium (49.0%). Most common adverse events with aripiprazole were headache, nausea, akathisia, sedation, and constipation; with lithium were nausea, headache, constipation, and tremor. CONCLUSIONS: Aripiprazole provided statistically significant improvement of acute mania within 2 days, continuing over 3 weeks and sustained over 12 weeks. The magnitude of improvement to Week 12 was similar with aripiprazole and lithium.


Asunto(s)
Antipsicóticos/uso terapéutico , Trastorno Bipolar/tratamiento farmacológico , Piperazinas/uso terapéutico , Quinolonas/uso terapéutico , Enfermedad Aguda , Adolescente , Adulto , Anciano , Antipsicóticos/efectos adversos , Aripiprazol , Trastorno Bipolar/diagnóstico , Trastorno Bipolar/psicología , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Método Doble Ciego , Femenino , Estudios de Seguimiento , Cefalea/inducido químicamente , Humanos , Compuestos de Litio/efectos adversos , Compuestos de Litio/uso terapéutico , Masculino , Persona de Mediana Edad , Náusea/inducido químicamente , Piperazinas/efectos adversos , Placebos , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Quinolonas/efectos adversos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Aumento de Peso
5.
Psychoneuroendocrinology ; 28 Suppl 1: 69-82, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12504073

RESUMEN

Human sexual function is complex and affected in many different ways by schizophrenia and the antipsychotic drugs used in its treatment. The evaluation of the effects of antipsychotics on sexual function in patients with schizophrenia is also complex because the deleterious effects of conventional antipsychotics are superimposed on the effects of the disease itself. Although not extensively researched, sexual dysfunction seems to be frequent in patients with schizophrenia, especially in men. Sexual dysfunction appears, in significant part, to be a direct consequence of dopamine antagonism, combined with indirect effects due to increased serum prolactin concentration. Atypical antipsychotics have a number of potential advantages over standard agents with regard to their impact on sexual function. Clinical reports indicate that atypical antipsychotics are associated with a lower incidence of sexual adverse events than conventional antipsychotics and that there may also be important differences between them in this regard. For example, dose-related increases in prolactin concentrations occur with risperidone whereas olanzapine is associated with mild and transient increases in long-term treatment. Treatment with clozapine does not result in prolactin elevation and, like olanzapine, only transient increases occur with ziprasidone therapy, but the risk of agranulocytosis with clozapine restricts its use. Quetiapine has no more effect on serum prolactin than placebo across its full dose range. Together with its low frequency of reproductive or hormonal side effects and a low incidence of extrapyramidal symptoms, the tolerability profile of quetiapine may be particularly beneficial for many patients. Sexual dysfunction can be an important source of distress to patients and adversely affects compliance, and is one of the factors that must be taken into account when selecting treatment.


Asunto(s)
Antipsicóticos/efectos adversos , Disfunciones Sexuales Fisiológicas/inducido químicamente , Antipsicóticos/uso terapéutico , Femenino , Humanos , Masculino , Esquizofrenia/complicaciones , Esquizofrenia/tratamiento farmacológico
6.
Eur J Immunol ; 31(7): 2087-93, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11449362

RESUMEN

A critical role for complement in the regulation of self tolerance has been proposed to explain the strong association between complement deficiency and autoimmunity. To elucidate the role of the classical pathway of complement in the maintenance of B cell tolerance, C1q-deficient (C1qa-/-) mice were bred with anti-hen egg lysozyme (HEL) immunoglobulin (Ig(HEL)) and soluble HEL (sHEL) transgenic mice. B cell tolerance was intact in C1qa-/- mice. In vivo, double-transgenic (Ig(HEL)/sHEL) C1qa-/- and wild-type control mice down-regulated surface immunoglobulin expression on splenocytes and equivalent numbers of HEL-binding B cells accumulated in the periphery. Maturation of B cells, evidenced by CD21 expression, was retarded to the same extent and at a similar time point. The frequency of anti-HEL-producing plasma cells and serum levels of anti-HEL immunoglobulin were comparably reduced in control and C1qa-/- double-transgenic mice compared to control Ig(HEL) and C1qa-/- Ig(HEL) mice. Furthermore, splenocytes from double-transgenic C1qa-/- or wild-type mice did not modulate intracellular calcium levels after stimulation with HEL in vitro. These data demonstrate that a stable form of B cell anergy persists in the periphery of C1qa-/- mice, suggesting that activation of the classical pathway by C1q is not essential for the maintenance of B cell tolerance in this transgenic model.


Asunto(s)
Linfocitos B/inmunología , Complemento C1q/genética , Vía Clásica del Complemento , Autotolerancia , Animales , Autoantígenos/inmunología , Médula Ósea/inmunología , Calcio/metabolismo , Anergia Clonal , Complemento C4b/inmunología , Inmunoglobulinas/inmunología , Hígado/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Muramidasa/inmunología , Células Plasmáticas/inmunología , Bazo/inmunología
7.
Biochemistry ; 39(44): 13614-24, 2000 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-11063599

RESUMEN

Structural analogues of the phytohormone (+)-abscisic acid (ABA) have been synthesized and tested as inhibitors of the catabolic enzyme (+)-ABA 8'-hydroxylase. Assays employed microsomes from suspension-cultured corn cells. Four of the analogues [(+)-8'-acetylene-ABA, (+)-9'-propargyl-ABA, (-)-9'-propargyl-ABA, and (+)-9'-allyl-ABA] proved to be suicide substrates of ABA 8'-hydroxylase. For each suicide substrate, inactivation required NADPH, increased with time, and was blocked by addition of the natural substrate, (+)-ABA. The most effective suicide substrate was (+)-9'-propargyl-ABA (K(I) = 0.27 microM). Several analogues were competitive inhibitors of ABA 8'-hydroxylase, of which the most effective was (+)-8'-propargyl-ABA (K(i) = 1.1 microM). Enzymes in the microsomal extracts also hydroxylated (-)-ABA at the 7'-position at a low rate. This activity was not inhibited by the suicide substrates, showing that the 7'-hydroxylation of (-)-ABA was catalyzed by a different enzyme from that which catalyzed 8'-hydroxylation of (+)-ABA. Based on the results described, a simple model for the positioning of substrates in the active site of ABA 8'-hydroxylase is proposed. In a representative physiological assay, inhibition of Arabidopsis thaliana seed germination, (+)-9'-propargyl-ABA and (+)-8'-acetylene-ABA exhibited substantially stronger hormonal activity than (+)-ABA itself.


Asunto(s)
Inhibidores Enzimáticos del Citocromo P-450 , Inhibidores Enzimáticos/química , Oxigenasas de Función Mixta/antagonistas & inhibidores , Ácido Abscísico/agonistas , Ácido Abscísico/análogos & derivados , Ácido Abscísico/química , Ácido Abscísico/metabolismo , Unión Competitiva , Sistema Enzimático del Citocromo P-450/química , Sistema Enzimático del Citocromo P-450/metabolismo , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/metabolismo , Germinación , Hidroxilación , Cinética , Oxigenasas de Función Mixta/química , Oxigenasas de Función Mixta/metabolismo , Reguladores del Crecimiento de las Plantas/síntesis química , Reguladores del Crecimiento de las Plantas/química , Reguladores del Crecimiento de las Plantas/metabolismo , Proteínas de Plantas , Semillas/enzimología , Semillas/fisiología , Especificidad por Sustrato
8.
Phytochemistry ; 53(3): 349-55, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10703056

RESUMEN

An anthracenone analogue of abscisic acid (ABA) was synthesized as a potential photoaffinity reagent and tested for biological activity. Reaction between 10,10'-dimethoxy-9-anthrone with two equivalents of the lithiated dianion of cis-3-methylpent-2-en-4-yn-1-ol afforded an acetylenic alcohol key intermediate. Subsequent reduction of the triple bond, functional group manipulation of the side chain alcohol and deprotection of the dimethoxy protected anthrone provided anthracenone ABA analogue 7 as a potential photoaffinity reagent for ABA-binding proteins. The effect of natural ABA and the potential photoaffinity anthracenone ABA 7 on corn cell growth was determined at various concentrations. The results show that anthracenone ABA 7 is perceived as ABA-like, although producing less inhibition than ABA itself. For example, 7 at 33 microM produces approximately the same inhibition as ABA at 10 microM.


Asunto(s)
Ácido Abscísico/análogos & derivados , Antracenos/química , Etiquetas de Fotoafinidad , Proteínas de Plantas/metabolismo , Ácido Abscísico/metabolismo , Células Cultivadas , Unión Proteica , Análisis Espectral , Zea mays/citología , Zea mays/metabolismo
9.
Curr Biol ; 10(4): 227-30, 2000 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-10704418

RESUMEN

Human autoimmune diseases thought to arise from the combined effects of multiple susceptibility genes include systemic lupus erythematosus (SLE) and autoimmune diabetes. Well-characterised polygenic mouse models closely resembling each of these diseases exist, and genetic evidence links receptors for the Fc portion of immunoglobulin G (FcR) with their pathogenesis in mice and humans [1] [2] [3]. FcRs may be activatory or inhibitory and regulate a variety of immune and inflammatory processes [4] [5]. FcgammaRII (CD32) negatively regulates activation of cells including B cells and macrophages [6]. FcgammaRII-deficient mice are prone to immune-mediated disease [7] [8] [9]. The gene encoding FcgammaRII, Fcgr2, is contained in genetic susceptibility intervals in mouse models of SLE such as the New Zealand Black (NZB) contribution to the (NZB x New Zealand White (NZW)) F1 strain [1] [10] [11] and the BXSB strain [12], and in human SLE [1] [2] [3]. We therefore sequenced Fcgr2 and identified a haplotype defined by deletions in the Fcgr2 promoter region that is present in major SLE-prone mouse strains (NZB, BXSB, SB/Le, MRL, 129 [13]) and non-obese diabetic (NOD) mice but absent in control strains (BALB/c, C57BL/6, DBA/2, C57BL/10) and NZW mice. The autoimmune haplotype was associated with reduced cell-surface expression of FcgammaRII on macrophages and activated B cells and with hyperactive macrophages resembling those of FcgammaRII-deficient mice, and is therefore likely to play an important role in the pathogenesis of SLE and possibly diabetes.


Asunto(s)
Autoinmunidad/genética , Lupus Eritematoso Sistémico/genética , Regiones Promotoras Genéticas , Receptores de IgG/genética , Animales , Linfocitos B/metabolismo , Secuencia de Bases , Expresión Génica , Haplotipos , Activación de Linfocitos , Macrófagos/metabolismo , Ratones , Datos de Secuencia Molecular , Eliminación de Secuencia
10.
Plant J ; 15(4): 501-10, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9753775

RESUMEN

Cyclin-dependent kinase (CDK) inhibitor genes encode low molecular weight proteins which have important functions in cell cycle regulation, development and perhaps also in tumorigenesis. The first plant CDK inhibitor gene ICK1 was recently identified from Arabidopsis thaliana. Although the C-terminal domain of ICK1 contained an important consensus sequence with the mammalian CDK inhibitor p27Kip1, the remainder of the deduced ICK1 sequence showed little similarity to any known CDK inhibitors. In vitro assays showed that recombinant ICK1 exhibited unique kinase inhibitory properties. In the present study we characterized ICK1 in terms of its gene structure, its interaction with both A. thaliana Cdc2a and CycD3, and its induction by the plant growth regulator, abscisic acid (ABA). ICK1 was expressed at a relatively low level in the tissues surveyed. However, ICK1 was induced by ABA, and along with ICK1 induction there was a decrease in Cdc2-like histone H1 kinase activity. These results suggest a molecular mechanism by which plant cell division might be inhibited by ABA. ICK1 clones were also identified from independent yeast two-hybrid screens using the CycD3 construct. The implication that ICK1 protein could interact with both Cdc2a and CycD3 was confirmed by in vitro binding assays. Furthermore, deletion analysis indicated that different regions of ICK1 are required for the interactions with Cdc2a and CycD3. These results provide a mechanistic basis for understanding the role of CDK inhibitors in cell cycle regulation in plant cells.


Asunto(s)
Ácido Abscísico/farmacología , Proteínas de Arabidopsis , Arabidopsis/genética , Proteínas de Ciclo Celular/genética , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Regulación de la Expresión Génica de las Plantas/fisiología , Proteína Quinasa CDC2/genética , Proteína Quinasa CDC2/metabolismo , Proteínas de Ciclo Celular/metabolismo , Clonación Molecular , Ciclina D3 , Proteínas Inhibidoras de las Quinasas Dependientes de la Ciclina , Ciclinas/genética , Ciclinas/metabolismo , ADN de Plantas/análisis , Dosificación de Gen , Datos de Secuencia Molecular , Unión Proteica , ARN Mensajero/análisis , ARN de Planta/análisis , Proteínas Recombinantes de Fusión , Análisis de Secuencia de ADN , Eliminación de Secuencia
11.
J Exp Med ; 187(11): 1789-97, 1998 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-9607920

RESUMEN

The role of the classical complement pathway in humoral immune responses was investigated in gene-targeted C1q-deficient mice (C1qA-/-). Production of antigen-specific immunoglobulin (Ig)G2a and IgG3 in primary and secondary responses to T cell-dependent antigen was significantly reduced, whereas IgM, IgG1, and IgG2b responses were similar in control and C1qA-/- mice. Despite abnormal humoral responses, B cells from C1qA-/- mice proliferated normally to a number of stimuli in vitro. Immune complex localization to follicular dendritic cells within splenic follicles was lacking in C1qA-/- mice. The precursor frequency of antigen-specific T cells was similar in C1qA-/- and wild-type mice. However, analysis of cytokine production by primed T cells in response to keyhole limpet hemocyanin revealed a significant reduction in interferon-gamma production in C1qA-/- mice compared with control mice, whereas interleukin 4 secretion was equivalent. These data suggest that the classical pathway of complement may influence the cytokine profile of antigen-specific T lymphocytes and the subsequent immune response.


Asunto(s)
Complemento C1q/inmunología , Interferón gamma/biosíntesis , Linfocitos T/inmunología , Animales , Anticuerpos/inmunología , Complejo Antígeno-Anticuerpo/inmunología , Antígenos/inmunología , Linfocitos B/inmunología , División Celular , Complemento C1q/deficiencia , Complemento C1q/genética , Vía Clásica del Complemento , Femenino , Interleucina-4/biosíntesis , Masculino , Ratones , Ratones Endogámicos C57BL
12.
Plant Physiol ; 114(1): 89-97, 1997 May.
Artículo en Inglés | MEDLINE | ID: mdl-12223691

RESUMEN

We report here the synthesis and biological activity of a new persistent abscisic acid (ABA) analog, 8[prime]-methylene ABA. This ABA analog has one additional carbon atom attached through a double bond to the 8[prime]-carbon of the ABA molecule. (+)-8[prime]-Methylene ABA is more active than the natural hormone (+)-ABA in inhibiting germination of cress seed and excised wheat embryos, in reducing growth of suspension-cultured corn cells, and in reducing transpiration in wheat seedlings. The (+)-8[prime]-methylene analog is slightly weaker than (+)-ABA in increasing expression of ABA-inducible genes in transgenic tobacco, but is equally active in stimulating a transient elevation of the pH of the medium of corn cell cultures. In corn cells, both (+)-ABA and (+)-8[prime]-methylene ABA are oxidized at the 8[prime] position. ABA is oxidized to phaseic acid and (+)-8[prime]-methylene ABA is converted more slowly to two isomeric epoxides. The alteration in the ABA structure causes the analog to be metabolized more slowly than ABA, resulting in longer-lasting and more effective biological activity relative to ABA.

14.
Eur J Immunol ; 26(2): 320-8, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8617298

RESUMEN

Rats from the allotype-marked PVG-RT7b and PVG-RT1u-RT7b strains were injected at birth with semi-allogenic F1 bone marrow (BM) cells from athymic nude rats (PVG-rnu/rnu x PVG-RT1u-rnu/rnu) to induce neonatal tolerance. As adults, 97% of the animals accepted donor-specific allogeneic skin grafts and a majority (65%) of rats were chimeric, expressing the major histocompatibility complex class I and allotype marker of the donor strain. Similar results were obtained when PVG-RT1u-RT7b rats were injected at birth with fully allogeneic PVG-rnu/rnu nude BM cells: as adults, 94% accepted donor-specific skin allografts and 76% of recipients were chimeric. Donor derived CD4 T cells, CD8 T cells and B cells were found in low numbers (less than 2%) in peripheral blood of rats made tolerant by F1 BM cells. A large proportion of T cells bore the phenotype of recent thymic emigrants, suggesting that they were newly produced. All the evidence was consistent with clonal deletion tolerance, induced centrally within the thymus. The thymus was chimeric and thymocytes failed to respond in vitro to alloantigens of the donor-specific haplotype; donor-specific skin allografts survived indefinitely on athymic nude recipients reconstituted with CD4+CD8- thymocytes or peripheral CD4 T cells from tolerant animals. The chimeric state was interesting, since the PVG and PVG-RT1u rat strains contain a natural killer (NK) cell system that rapidly eliminates (within 24 h) intravenously injected allogeneic or semi-allogeneic lymphocytes--a phenomenon known as allogeneic lymphocyte cytotoxicity or ALC. When neonatal tolerant rats were tested, the ALC index (a measure of cell killing) was unchanged in nonchimeric tolerant rats and significantly altered (reduced killing), but not abolished in chimeric animals. Hence, the injection of allogeneic BM cells which induced specific tolerance in the T cell population failed to tolerize the NK cell system, allowing the constant killing of newly produced donor-derived lymphocytes and putting at risk the very survival of the allogenic BM cells. This has interesting implications for clinical transplantation.


Asunto(s)
Animales Recién Nacidos/inmunología , Tolerancia Inmunológica , Depleción Linfocítica , Quimera por Radiación/inmunología , Trasplante de Piel , Animales , Trasplante de Médula Ósea , Supresión Clonal/genética , Pruebas Inmunológicas de Citotoxicidad , Citotoxicidad Inmunológica/genética , Tolerancia Inmunológica/genética , Inmunidad Activa , Inmunidad Innata/genética , Isoantígenos/genética , Isoantígenos/inmunología , Transfusión de Linfocitos , Ratas , Ratas Endogámicas , Ratas Desnudas
15.
Plant Mol Biol ; 28(4): 605-17, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7647294

RESUMEN

The Arabidopsis thaliana genes kin1 and cor6.6 belong to the same family and were expressed at higher levels following low temperature and ABA treatments. In an attempt to elucidate the mechanism of gene regulation by low temperature, the relationship between low-temperature- and abscisic acid (ABA)-induced gene expression and possible differential expression of the two genes, we have cloned a 5.3 kb genomic fragment harboring kin1 and cor6.6 and their respective 5' sequences. The putative promoters of both genes were fused to the beta-glucuronidase (GUS) coding sequence and GUS expression was analysed in transgenic tobacco and Arabidopsis plants. The cor6.6 promoter produced a higher basal level of expression than the kin1 promoter in transgenic tobacco. Enzyme assays of inducible GUS activity in transgenic Arabidopsis and tobacco plants showed that GUS activity directed by both kin1 and cor6.6 promoters was significantly induced by ABA, dehydration and osmoticum, but not by low temperature. Northern analysis revealed, in contrast, that GUS mRNA was significantly induced in these transgenic plants by low temperature. Further analysis showed that, at low temperature, GUS protein synthesis from the induced GUS mRNA was inhibited. Together these results reveal induction of kin1 and cor6.6 transcription by low temperature, exogenous ABA and dehydration. However, low-temperature expression is dramatically reduced at the translational level.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas/genética , Proteínas de Plantas/genética , Regiones Promotoras Genéticas/genética , Ácido Abscísico/farmacología , Proteínas Anticongelantes , Arabidopsis/efectos de los fármacos , Secuencia de Bases , Clonación Molecular , Frío , Inducción Enzimática , Genes Reporteros , Glicoproteínas/genética , Datos de Secuencia Molecular , Familia de Multigenes/genética , Presión Osmótica , Fosfoproteínas/genética , Plantas Modificadas Genéticamente , Plantas Tóxicas , Proteínas Serina-Treonina Quinasas/genética , ARN Mensajero/análisis , Proteínas Recombinantes de Fusión , Homología de Secuencia de Ácido Nucleico , Nicotiana/genética , Transformación Genética
16.
Plant Mol Biol ; 28(4): 619-34, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7647295

RESUMEN

The ability of most higher plants to withstand freezing can be enhanced by cold acclimation, although the freezing tolerance of plant tissues is also affected by their developmental stage. In addition, low temperature has pleiotropic effects on many plant developmental processes such as vernalization. The interaction between plant development and low temperature implies that some genes are regulated by both environmental factors and developmental cues. Although a number of cold-inducible genes from plants have been identified, information concerning their regulation during plant development is limited. In order to understand their developmental regulation and obtain possible clues as to function, the promoters of kin1 and cor6.6, two cold- and abscisic acid (ABA)-regulated genes from Arabidopsis thaliana, were fused to the beta-glucuronidase (GUS)-coding sequence and the resulting constructs were used to transform tobacco and A. thaliana. Transgenic plants with either the kin1 or cor6.6 promoter showed strong GUS expression in pollen, developing seeds, trichomes and, most interestingly, in guard cells. During pollen development, maximum GUS activity was found in mature pollen. In contrast, the maximum GUS activity during seed development was during early embryogenesis. These patterns of expression distinguish kin1 and cor6.6 from related lea genes which are strongly expressed during late embryogenesis. There was no major qualitative difference in patterns of GUS expression between kin1 and cor6.6 promoters and the results were similar for transgenic tobacco and Arabidopsis. Considering the results described, as well as those in an accompanying paper (Wang et al., 1995, Plant Mol Biol 28: 605-617 (this issue), we suggest that osmotic potential might be a major factor in regulating the expression of kin1 and cor6.6 during several developmental processes. The implication of the results for possible function of the gene products is discussed.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Fosfoproteínas/genética , Proteínas de Plantas/genética , Regiones Promotoras Genéticas/genética , Proteínas Serina-Treonina Quinasas/genética , Ácido Abscísico/farmacología , Adaptación Biológica/genética , Arabidopsis/citología , Arabidopsis/efectos de los fármacos , Frío , Glucuronidasa/biosíntesis , Histocitoquímica , Microscopía , Hojas de la Planta/citología , Hojas de la Planta/metabolismo , Plantas Modificadas Genéticamente , Plantas Tóxicas , Polen/metabolismo , Proteínas Recombinantes de Fusión/biosíntesis , Semillas/anatomía & histología , Semillas/crecimiento & desarrollo , Semillas/metabolismo , Distribución Tisular , Nicotiana/genética , Transformación Genética
17.
Hosp Community Psychiatry ; 45(9): 916-9, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7989025

RESUMEN

Health care reform proposals based on a single-payer system of health care insurance were introduced in the U.S. Congress in 1992 and 1993 but were superseded by the Clinton Administration's health care reform proposal, which was based on managed competition. In a single-payer system, the government collects all health care funding and pays private- and public-sector providers; similar providers are paid the same rate. Other features include consumer choice of providers, distribution of risk of high utilization over the entire nation, and control of health care expenses via an annual national health care budget. Such proposals cover outpatient, inpatient, and long-term care and case management services for mental illness and substance abuse disorders, call for periodic utilization review of continuing mental health care, and eliminate the distinction between public and private services based on limits of coverage. The last provision particularly affects severely or chronically mentally ill persons who are likely to exhaust their private insurance coverage.


Asunto(s)
Reforma de la Atención de Salud/economía , Reforma de la Atención de Salud/organización & administración , Trastornos Mentales/rehabilitación , Servicios de Salud Mental/economía , Servicios de Salud Mental/organización & administración , National Health Insurance, United States , Trastornos Relacionados con Sustancias/rehabilitación , Humanos , Estados Unidos
18.
Plant Physiol ; 106(1): 135-142, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12232311

RESUMEN

The metabolism and effects of (+)-S- and (-)-R-abscisic acid (ABA) and some metabolites were studied in maize (Zea mays L. cv Black Mexican Sweet) suspension-cultured cells. Time-course studies of metabolite formation were performed in both cells and medium via analytical high-performance liquid chromatography. Metabolites were isolated and identified using physical and chemical methods. At 10 [mu]M concentration and 28[deg] C, (+)-ABA was metabolized within 24 h, yielding natural (-)-phaseic acid [(-)-PA] as the major product. The unnatural enantiomer (-)-ABA was less than 50% metabolized within 24 h and gave primarily (-)-7[prime]-hydroxyABA [(-)-7[prime]-HOABA], together with (+)-PA and ABA glucose ester. The distribution of metabolites in cells and medium was different, reflecting different sites of metabolism and membrane permeabilities of conjugated and nonconjugated metabolites. The results imply that (+)-ABA was oxidized to (-)-PA inside the cell, whereas (-)-ABA was converted to (-)-7[prime]-HOABA at the cell surface. Growth of maize cells was inhibited by both (+)- and (-)-ABA, with only weak contributions from their metabolites. The concentration of (+)-ABA that caused a 50% inhibition of growth of maize cells was approximately 1 [mu]M, whereas that for its metabolite (-)-PA was approximately 50 [mu]M. (-)-ABA was less active than (+)-ABA, with 50% growth inhibition observed at about 10 [mu]M. (-)-7[prime]-HOABA was only weakly active, with 50% inhibition caused by approximately 500 [mu]M. Time-course studies of medium pH indicated that (+)-ABA caused a transient pH increase (+0.3 units) at 6 h after addition that was not observed in controls or in samples treated with (-)-PA. The effect of (-)-ABA on medium Ph was marginal. No racemization at C-1[prime] of (+)-ABA, (-)-ABA, or metabolites was observed during the studies.

19.
Biochem Cell Biol ; 72(3-4): 152-6, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7818849

RESUMEN

Evidence for a small size protein (ca. 3500 kDa) exhibiting epitopic homology to the Atlantic winter flounder antifreeze protein (AFP) is found in the snow molds Coprinus psychromorbidus, Myriosclerotinia borealis, and Typhula incarnata. The protein shows strong cross-reactivity with antisera specific for the flounder AFP. Preliminary studies suggest that the protein is synthesized in response to lowering the culture temperature, and that it is membrane associated and, therefore, may function in an analogous capacity to the fish AFP. Also, the protein is shown to have antifreeze properties as determined by nuclear magnetic resonance microimaging experiments.


Asunto(s)
Agaricales/química , Coprinus/química , Proteínas Fúngicas/química , Glicoproteínas/química , Homología de Secuencia , Animales , Proteínas Anticongelantes , Western Blotting , Lenguado , Congelación , Punto Isoeléctrico , Peso Molecular
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