RESUMO
Xavier University of Louisiana (XULA) is the only historically Black and Catholic institution of higher education in the United States. XULA's mission focuses on "the promotion of a more just and humane society" by educating students in a diverse learning environment. Even though Xavier's reputation in the sciences attracts many of the best and brightest students in the nation, the University also continues to provide an excellent educational opportunity to many students who, due to socioeconomic disparities, lack the appropriate preparation for college. The ultimate goal of Project Pathways, the National Institutes of Health (NIH)-funded BUILD (Building Infrastructure Leading to Diversity) Program at Xavier, is to increase the number of students who enter graduate programs in biomedical disciplines, successfully earn terminal degrees, and enter the biomedical research workforce. Xavier's plan to meet this challenge is based on a holistic approach, providing an integrated and coordinated student support and research skills training network. This coordinated effort cuts across academic departments in biomedical disciplines, academic support offices that include the Student Academic Success Office (SASO), the Office of Career Services (OCS), and the Center for Undergraduate Research and Graduate Opportunity (CURGO), as well as the Center for the Advancement of Teaching and Faculty Development (CAT+FD) for faculty support and mentor training. This work seeks to counter the regular practice at higher education institutions that have yet to address the importance of integrated programming across academic programs, student support programs, and research programs. This lack of coordinated and integrated programming often leads to duplication of efforts and ineffective use of resources. Xavier's BUILD program intentionally provides mechanisms and safeguards to ensure that coordination and integration occur at all levels. The overall hypothesis of Project Pathways is that when in a systematic way underrepresented minorities are provided with: early awareness and deepening exposure to biomedical careers;supportive relationships for students as they move through the pathway;suitable infrastructure; andmeaningful student engagement in biomedical research experiences and adequate research resources, a higher number will succeed in first entering, and later successfully completing graduate programs, leading to increased diversity in the biomedical research workforce. Preliminary assessment results are very encouraging; these results show higher course pass rates and better student preparation overall. The Project Pathways' initiatives can be replicated at other institutions with similar goals.
RESUMO
An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ((133)Cs and (137)Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and (133)Cs mass concentrations with (137)Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 ± 6.79 g kg(-1) for K (mean ± SD, dwt), 0.40 ± 0.09 g kg(-1) for Rb, 8.7 ± 4.36 mg kg(-1) for (133)Cs and 63.7 ± 24.2 kBq kg(-1) for (137)Cs. The mass concentrations of (133)Cs correlated with (137)Cs activity concentrations (r = 0.61). There was correlation between both (133)Cs concentrations (r = 0.75) and (137)Cs activity concentrations (r = 0.44) and Rb, but the (137)Cs/(133)Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The (133)Cs mass concentrations, (137)Cs activity concentrations and (137)Cs/(133)Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, (133)Cs and (137)Cs in sporocarps of S. variegatus is similar to other fungal species.
Assuntos
Basidiomycota/metabolismo , Radioisótopos de Césio/farmacocinética , Acidente Nuclear de Chernobyl , Monitoramento Ambiental/estatística & dados numéricos , Carpóforos/metabolismo , Potássio/farmacocinética , Rubídio/farmacocinética , Basidiomycota/química , Radioisótopos de Césio/análise , Carpóforos/química , Potássio/análise , Rubídio/análise , Especificidade da Espécie , Suécia , ÁrvoresRESUMO
We examined the long-term effects of a single application of potassium (K) fertilizer (100 kg K ha(-1)) in 1992 on (137)Cs uptake in a forest ecosystem in central Sweden. (137)Cs activity concentrations were determined in three low-growing perennial shrubs, heather (Calluna vulgaris), lingonberry (Vaccinium vitis-idaea) and bilberry (Vaccinium myrtillus), and in four wild fungal species (Cortinarius semisanguineus, Lactarius rufus, Rozites caperata and Suillus variegatus). Uptake of (137)Cs by plants and fungi growing on K-fertilized plots 17 years after application of the K fertilizer was significantly lower than in corresponding species growing in a non-fertilized control area. The (137)Cs activity concentration was 21-58% lower in fungal sporocarps and 40-61% lower in plants in the K-fertilized area compared with the control. Over the study period, this decrease in (137)Cs activity concentration was more consistent in plants than in fungi, although the effect was statistically significant and strongly pronounced in all species. The effect of K fertilization in reducing (137)Cs activity concentration in fungi and plants decreased over time but was still significant in 2009, 17 years after fertilization. This suggests that application of K fertilizer to forests is an appropriate and effective long-term measure to decrease radiocaesium accumulation in plants and fungi.
Assuntos
Basidiomycota/metabolismo , Calluna/metabolismo , Radioisótopos de Césio/farmacocinética , Ecossistema , Fertilizantes , Potássio/farmacologia , Árvores , Vaccinium/metabolismo , Basidiomycota/efeitos dos fármacos , Basidiomycota/crescimento & desenvolvimento , Calluna/efeitos dos fármacos , Calluna/crescimento & desenvolvimento , Especificidade da Espécie , Estatísticas não Paramétricas , Suécia , Fatores de Tempo , Vaccinium/efeitos dos fármacos , Vaccinium/crescimento & desenvolvimentoRESUMO
In area, New Caledonia is the smallest of the world's 25 official biodiversity hotspots, but in many taxonomic groups, the island has the highest concentration of species on earth, particularly so in the freshwater insect order Trichoptera. This study aims at applying molecular data and morphology for estimating the real species diversity of the genus Agmina on New Caledonia and investigating potential effects of ultramafic rock substrate on diversification. A dated molecular phylogeny was applied to study diversity and diversification related to geological substrate using the dispersal-extinction-cladogenesis model, diva and Bayesian ancestral character reconstruction. More than 47 species (>63%) were unknown to science. Initial radiation occurred on ultramafic substrate followed by several independent dispersal events to nonultramafic substrate. The rate of shift from ultramafic to nonultramafic substrate was significantly higher than the rate of shift in the opposite direction, indicating a possible cost associated with living on ultramafic substrate.
Assuntos
Biodiversidade , Evolução Biológica , Sedimentos Geológicos , Insetos , Animais , Teorema de Bayes , Nova Caledônia , FilogeografiaRESUMO
Radiocaesium ((137)Cs) was widely deposited over large areas of forest in Sweden as a result of the Chernobyl accident in 1986 and many people in Sweden eat wild fungi and game obtained from these contaminated forests. In terms of radioisotope accumulation in the food chain, it is well known that fungal sporocarps efficiently accumulate radiocaesium ((137)Cs), as well as the alkali metals potassium (K), rubidium (Rb) and caesium (Cs). The fungi then enhance uptake of these elements into host plants. This study compared the accumulation of these three alkali metals in bulk soil, rhizosphere, soil-root interface, fungal mycelium and sporocarps of mycorrhizal fungi in a Swedish forest. The soil-root interface was found to be distinctly enriched in K and Rb compared with the bulk soil. Potassium concentrations increased in the order: bulk soilAssuntos
Césio/análise
, Fungos/química
, Potássio/análise
, Rubídio/análise
, Solo/análise
, Isótopos de Césio/análise
, Radioisótopos de Césio/análise
, Exposição Ambiental/análise
, Monitoramento Ambiental
, Cinza Radioativa/análise
, Suécia
, Árvores
RESUMO
We record the distribution of (137)Cs, K, Rb and Cs within individual Sphagnum plants (down to 20cm depth) as well as (137)Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris(137)Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher (137)Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of (137)Cs within the plants. The patterns of (137)Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The (137)Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10cm) of the plant (r=0.50). The strongest correlations were revealed between (137)Cs and Rb (r=0.89), and between (137)Cs and stable Cs (r=0.84). This suggests similarities between (137)Cs and Rb in uptake and relocation within the Sphagnum, but that (137)Cs differs from K.
Assuntos
Radioisótopos de Césio/análise , Ecossistema , Plantas/metabolismo , Radioisótopos de Potássio/análise , Radioisótopos de Rubídio/análise , Poluentes Radioativos do Solo/análise , Sphagnopsida/metabolismo , Radioisótopos de Césio/metabolismo , Cyperaceae/metabolismo , Geografia , Radioisótopos de Potássio/metabolismo , Radioisótopos de Rubídio/metabolismo , Poluentes Radioativos do Solo/metabolismo , Suécia , Vaccinium/metabolismo , Áreas AlagadasRESUMO
The vertical distribution of (137)Cs activity in peat soil profiles and (137)Cs activity concentration in plants of various species was studied in samples collected at two sites on a raised bog in central Sweden. One site (open bog) was in an area with no trees and only a few sparsely growing plant species, while the other (low pine) was less than 100 m from the open bog site and had slowly growing Scots pine, a field layer dominated by some ericaceous plants and ground well-covered by plants. The plant samples were collected in 2004-2007 and were compared with samples collected in 1989 from the same open bog and low pine sites. Ground deposition of (137)Cs in 2005 was similar at both sites, 23,000 Bq m(-2). In the open bog peat profile it seems to be an upward transport of caesium since a clear peak of (137)Cs activity was found in the uppermost 1-4 cm of Sphagnum layers, whereas at the low pine site (137)Cs was mainly found in deeper (10-12 cm) layers. The migration rate was 0.57 cm yr(-1) at the open bog site and the migration centre of (137)Cs was at a depth of 10.7, while the rate at the low pine site was 0.78 cm yr(-1) and the migration centre was at 14.9 cm. Heather (Calluna vulgaris) was the plant species with the highest (137)Cs activity concentrations at both sites, 43.5 k Bq(-1) DM in 1989 decreasing to 20.4 in 2004-2007 on open bog and 22.3 k Bq kg(-1) DM in 1989 decreasing to 11.2 k Bq(-1) DM by the period 2004-2007 on the low pine site. (137)Cs transfer factors in plants varied between 0.88 and 1.35 on the open bog and between 0.48 and 0.69 m(2)kg(-1) DM at the low pine site.
Assuntos
Radioisótopos de Césio/análise , Monitoramento Ambiental , Poluentes Radioativos do Solo/análise , Áreas Alagadas , Plantas/química , SuéciaRESUMO
A method for quantitative assessment of 137Cs availability to plants in forest ecosystems on the basis of soil properties has been developed. It is shown that the experimental dependencies of 137Cs soil-to-plant transfer factor (TFag) for fern and bilberry on the bioavailability factor calculated on the basis of soil characteristics of root layer: 137Cs exchangeability, exchangeable Ca, effective selectivity coefficient, were satisfactory described by linear function. The advantage of the proposed method is that the necessary soil characteristics can be taken from the reference literature, evaluated using empirical correlations or determined with standard agrochemical procedures.
Assuntos
Radioisótopos de Césio/metabolismo , Modelos Estatísticos , Plantas/metabolismo , Poluentes Radioativos do Solo/metabolismo , Disponibilidade Biológica , Radioisótopos de Césio/farmacocinética , Ecossistema , Gleiquênias/metabolismo , Modelos Lineares , Raízes de Plantas/metabolismo , Poluentes Radioativos do Solo/farmacocinética , Árvores , Vaccinium myrtillus/metabolismoRESUMO
SB-219383 and its analogues are a class of potent and specific inhibitors of bacterial tyrosyl-tRNA synthetases. Crystal structures of these inhibitors have been solved in complex with the tyrosyl-tRNA synthetase from Staphylococcus aureus, the bacterium that is largely responsible for hospital-acquired infections. The full-length enzyme yielded crystals that diffracted to 2.8 A resolution, but a truncated version of the enzyme allowed the resolution to be extended to 2.2 A. These inhibitors not only occupy the known substrate binding sites in unique ways, but also reveal a butyl binding pocket. It was reported that the Bacillus stearothermophilus TyrRS T51P mutant has much increased catalytic activity. The S. aureus enzyme happens to have a proline at position 51. Therefore, our structures may contribute to the understanding of the catalytic mechanism and provide the structural basis for designing novel antimicrobial agents.
Assuntos
Inibidores Enzimáticos/química , Staphylococcus aureus/enzimologia , Tirosina-tRNA Ligase/química , Sequência de Aminoácidos , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Cristalização , Cristalografia por Raios X , Dipeptídeos/química , Dipeptídeos/farmacologia , Inibidores Enzimáticos/farmacologia , Furanos/química , Furanos/farmacologia , Modelos Moleculares , Dados de Sequência Molecular , Piperidinas/química , Piperidinas/farmacologia , Conformação Proteica , Homologia de Sequência de Aminoácidos , Tirosina-tRNA Ligase/antagonistas & inibidoresRESUMO
The steady-state kinetics of a full-length and truncated form of the type 2 human methionine aminopeptidase (hMetAP2) were analyzed by continuous monitoring of the amide bond cleavage of various peptide substrates and methionyl analogues of 7-amido-4-methylcoumarin (AMC) and p-nitroaniline (pNA), utilizing new fluorescence-based and absorbance-based assay substrates and a novel coupled-enzyme assay method. The most efficient substrates for hMetAP2 appeared to be peptides of three or more amino acids for which the values of k(cat)/K(m) were approximately 5 x 10(5) M(-1) min(-1). It was found that while the nature of the P1' residue of peptide substrates dictates the substrate specificity in the active site of hMetAP2, the P2' residue appears to play a key role in the kinetics of peptidolysis. The catalytic efficiency of dipeptide substrates was found to be at least 250-fold lower than those of the tripeptides. This substantially diminished catalytic efficiency of hMetAP2 observed with the alternative substrates MetAMC and MetpNA is almost entirely due to the reduction in the turnover rate (k(cat)), suggesting that cleavage of the amide bond is at least partially rate-limiting. The 107 N-terminal residues of hMetAP2 were not required for either the peptidolytic activity of the enzyme or its stability. Steady-state kinetic comparison and thermodynamic analyses of an N-terminally truncated form and full-length enzyme yielded essentially identical kinetic behavior and physical properties. Addition of exogenous Co(II) cation was found to significantly activate the full-length hMetAP2, while Zn(II) cation, on the other hand, was unable to activate hMetAP2 under any concentration that was tested.
Assuntos
Aminopeptidases/metabolismo , Metaloendopeptidases/metabolismo , Substituição de Aminoácidos , Aminopeptidases/antagonistas & inibidores , Aminopeptidases/química , Aminopeptidases/genética , Anilidas , Cátions Bivalentes , Dicroísmo Circular , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Cinética , Metaloendopeptidases/antagonistas & inibidores , Metaloendopeptidases/química , Metaloendopeptidases/genética , Metais/metabolismo , Norleucina/análogos & derivados , Norleucina/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Espectrofotometria , Especificidade por SubstratoRESUMO
Amyloid 39-42 beta -peptides are the main components of amyloid plaques found in the brain of Alzheimer's disease patients. Amyloid 39-42 beta-peptide is formed from amyloid precursor protein by the sequential action of beta- and gamma-secretases. Asp-2 is a transmembrane aspartic protease expressed in the brain, shown to have beta-secretase activity. Mature Asp-2 has four N-glycosylation sites. In this report we have characterized the carbohydrate structures in this glycoprotein expressed in three different cell lines, namely Chinese hamster ovary, CV-1 origin of SV40, and baculovirus-infected SF9 cells. Biantennary and triantennary oligosaccharides of the "complex" type were released from glycoprotein expressed in the mammalian cells, whereas mannose-rich glycans were identified from glycoprotein synthesized in the baculovirus-infected cells. Site-directed mutagenesis of the asparagine residues at amino acid positions 153, 172, 223, and 354 demonstrate that the protease activity of Asp-2 is dependent on its glycosylation.
Assuntos
Doença de Alzheimer/enzimologia , Ácido Aspártico Endopeptidases/química , Ácido Aspártico Endopeptidases/metabolismo , Glicoproteínas/metabolismo , Oligossacarídeos/química , Polissacarídeos/metabolismo , Secretases da Proteína Precursora do Amiloide , Animais , Ácido Aspártico Endopeptidases/genética , Encéfalo/enzimologia , Células CHO , Configuração de Carboidratos , Sequência de Carboidratos , Linhagem Celular , Cricetinae , Endopeptidases , Glicoproteínas/química , Glicoproteínas/genética , Glicosilação , Humanos , Dados de Sequência Molecular , Polissacarídeos/química , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Spodoptera , TransfecçãoRESUMO
Little is known about the differential long-term outcome from surgical and nonsurgical therapy in patients with chronic epilepsy. In the present study, 161 surgically or nonsurgically treated patients with drug-resistant temporal lobe epilepsy (TLE) were re-evaluated according to a detailed clinical, neuropsychological, and psychosocial protocol with a mean follow-up interval of 58 months. Freedom from seizures was achieved in 64% of the surgical group; yet 23% of the nonsurgical patients became seizure-free as a result of modifications in drug therapy. Generally, socioeconomic development was poorer in nonsurgical than in surgical patients. Freedom from seizures, employment, and the absence of depression were significant determinants of better quality of life. As for neuropsychological outcome, verbal memory impairment was common after left-sided temporal resection; however, there was no evidence of a marked progression of cognitive impairment after the first postoperative year. In nonsurgical patients, too, cognitive capacities were surprisingly stable over time, although persisting seizures and good baseline performance predicted a poorer neuropsychological outcome.
Assuntos
Cognição , Epilepsia do Lobo Temporal/psicologia , Memória , Qualidade de Vida , Aprendizagem Verbal , Adulto , Escolaridade , Emprego , Epilepsia do Lobo Temporal/tratamento farmacológico , Epilepsia do Lobo Temporal/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Recidiva , Estatísticas não Paramétricas , Resultado do TratamentoRESUMO
Caspases have been strongly implicated to play an essential role in apoptosis. A critical question regarding the role(s) of these proteases is whether selective inhibition of an effector caspase(s) will prevent cell death. We have identified potent and selective non-peptide inhibitors of the effector caspases 3 and 7. The inhibition of apoptosis and maintenance of cell functionality with a caspase 3/7-selective inhibitor is demonstrated for the first time, and suggests that targeting these two caspases alone is sufficient for blocking apoptosis. Furthermore, an x-ray co-crystal structure of the complex between recombinant human caspase 3 and an isatin sulfonamide inhibitor has been solved to 2.8-A resolution. In contrast to previously reported peptide-based caspase inhibitors, the isatin sulfonamides derive their selectivity for caspases 3 and 7 by interacting primarily with the S(2) subsite, and do not bind in the caspase primary aspartic acid binding pocket (S(1)). These inhibitors blocked apoptosis in murine bone marrow neutrophils and human chondrocytes. Furthermore, in camptothecin-induced chondrocyte apoptosis, cell functionality as measured by type II collagen promoter activity is maintained, an activity considered essential for cartilage homeostasis. These data suggest that inhibiting chondrocyte cell death with a caspase 3/7-selective inhibitor may provide a novel therapeutic approach for the prevention and treatment of osteoarthritis, or other disease states characterized by excessive apoptosis.
Assuntos
Apoptose , Inibidores de Caspase , Inibidores Enzimáticos/química , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Sítios de Ligação , Camptotecina/farmacologia , Caspase 3 , Caspase 7 , Condrócitos/efeitos dos fármacos , Colágeno/genética , Cristalografia por Raios X , Inibidores Enzimáticos/farmacologia , Humanos , Isatina/análogos & derivados , Camundongos , Modelos Moleculares , Estrutura Molecular , Neutrófilos/efeitos dos fármacos , Neutrófilos/enzimologia , Osteoartrite/tratamento farmacológico , Regiões Promotoras Genéticas , Proteínas Recombinantes/química , Sulfonamidas/química , Sulfonamidas/farmacologiaRESUMO
Histone acetylation alters chromatin state by modifying lysines on histone and plays an important role in modulating gene transcription. A dynamic balance of histone acetylation/deacetylation is maintained by histone acetyltransferases and histone deacetylases. Emerging evidence suggests that a family of histone deacetylases may exist to regulate diverse cellular functions, including chromatin structure, gene expression, cell cycle progression, and oncogenesis. We describe here a novel human histone deacetylase, named HDAC8, cloned from human kidney. HDAC8 encodes 377 amino acid residues and shares extensive homology to several known HDACs, in particular a histone deacetylase from Arabidopsis thaliana. Northern blot analyses revealed that HDAC8 expression pattern for HDAC8 is distinct from that for HDAC1 and HDAC3, and expression of HDAC8 mRNA occurs in multiple organs including heart, lung, kidney, and pancreas. HDAC8 mRNA was also observed in several cell lines derived from cancerous tissues. When expressed in HEK293 cells, HDAC8 exhibited deacetylase activity toward acetylated histone, indicating that this protein is a bona fide histone deacetylase. Its histone deacetylase activity was inhibited by trichostatin and other known histone deacetylase inhibitors. Furthermore, active recombinant HDAC8 was expressed and purified from Escherichia coli. When ectopically expressed in cells, HDAC8 was found to be localized to the nucleus. Co-transfection experiments demonstrated that expression of HDAC8 repressed a viral SV40 early promoter activity. These results indicate that HDAC8 is a novel member of the histone deacetylase family, which may play a role in the development of a broad range of tissues and potentially in the etiology of cancer.
Assuntos
Histona Desacetilases/química , Histona Desacetilases/metabolismo , Rim/enzimologia , Proteínas Repressoras/química , Proteínas Repressoras/metabolismo , Células 3T3 , Sequência de Aminoácidos , Animais , Arabidopsis/enzimologia , Sequência de Bases , Linhagem Celular , Clonagem Molecular , Histona Desacetilases/genética , Humanos , Camundongos , Dados de Sequência Molecular , Especificidade de Órgãos , Filogenia , RNA Mensageiro/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Repressoras/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transcrição Gênica , Transfecção , Células Tumorais CultivadasRESUMO
SK&F 107647, a previously described synthetic immunomodulatory peptide, indirectly stimulates bone marrow progenitor cells and phagocytic cells, and enhances host defense effector mechanisms in bacterial and fungal infection models in vivo. In vitro, SK&F 107647 induces the production of a soluble mediator that augments colony forming cell (CFU-GM) formation in the presence of CSFs. In this paper we purified and sequenced the stromal cell-derived hematopoietic synergistic factors (HSF) secreted from both murine and human cell lines stimulated with SK&F 107647. Murine HSF is an N-terminal 4-aa truncated form of the CXC chemokine, KC, while human HSF was identified as an N-terminal 4-aa truncated form of the CXC chemokine, GRO beta. In comparison to their full-length forms, truncated KC and truncated GRO beta were 10 million times more potent as synergistic growth stimulants for CFU-GM. Enhanced potency of these novel truncated chemokines relative to their full-length forms was also demonstrated in respiratory burst assays, CD11b Ag expression, and intracellular killing of the opportunistic pathogen, Candida albicans. Administration of truncated KC significantly enhanced survival of mice lethally infected with C. albicans. The results reported herein delineate the biological mechanism of action of SK&F 107647, which functions via the induction of unique specific truncated forms of the chemokines KC and GRO beta. To our knowledge, this represents the first example where any form of KC or GRO beta were purified from marrow stromal cells. Additionally, this is the first demonstration of in vivo efficacy of a CXC chemokine in an animal infectious fungal disease model.
Assuntos
Antifúngicos/isolamento & purificação , Quimiocinas CXC/isolamento & purificação , Fatores Quimiotáticos/isolamento & purificação , Substâncias de Crescimento/isolamento & purificação , Peptídeos e Proteínas de Sinalização Intercelular , Fragmentos de Peptídeos/isolamento & purificação , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Sequência de Aminoácidos , Animais , Antifúngicos/sangue , Antifúngicos/imunologia , Células da Medula Óssea/química , Células da Medula Óssea/imunologia , Candidíase/imunologia , Candidíase/mortalidade , Candidíase/prevenção & controle , Linhagem Celular , Quimiocina CXCL1 , Quimiocinas CXC/sangue , Quimiocinas CXC/genética , Quimiocinas CXC/imunologia , Fatores Quimiotáticos/sangue , Fatores Quimiotáticos/genética , Fatores Quimiotáticos/imunologia , Sinergismo Farmacológico , Feminino , Substâncias de Crescimento/sangue , Substâncias de Crescimento/genética , Substâncias de Crescimento/imunologia , Humanos , Soros Imunes/farmacologia , Injeções Intraperitoneais , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Ativação de Neutrófilo/imunologia , Oligopeptídeos/administração & dosagem , Oligopeptídeos/farmacologia , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Proteínas Recombinantes/química , Células Estromais/química , Células Estromais/imunologiaAssuntos
Benzazepinas/farmacologia , Piridinas/farmacologia , Receptores de Vitronectina/antagonistas & inibidores , Animais , Benzazepinas/síntese química , Benzazepinas/farmacocinética , Disponibilidade Biológica , Reabsorção Óssea/prevenção & controle , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Meia-Vida , Humanos , Mimetismo Molecular , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Piridinas/síntese química , Piridinas/farmacocinética , Ratos , Estereoisomerismo , Distribuição TecidualRESUMO
The three-dimensional structure of a novel four amino acid truncated form of the CXC chemokine GRObeta [5-73] isolated from bone marrow stromal cells with potent hematopoietic and anti-infective activities has been determined by two-dimensional (1)H nuclear magnetic resonance (NMR) spectroscopy in solution. On the basis of 1878 upper distance constraints derived from nuclear Overhauser effects (NOE) and 314 dihedral angle constraints, a group of 20 conformers representing the solution structure of the human GRObeta [5-73] was computed with the program DYANA. At the concentrations used for NMR study, GRObeta [5-73] forms a dimer in solution that is architectured by a six-stranded antiparallel beta-sheet (residues 25 to 29, 39 to 44, 49 to 52) and a pair of helices (residues 58 to 68) with 2-fold symmetry, while the C terminus of the protein is disordered. The average of the pairwise root-mean-square deviations of individual NMR conformers relative to the mean coordinates for the backbone atoms N, C(alpha) and C' of residues 5 to 68 is 0.47 A. Overall, the global fold of GRObeta [5-73] is similar to that of the previously reported NMR structure of GROalpha and the NMR and X-ray structures of interleukin-8. Among these three CXC chemokines, GRObeta [5-73] is most similar in structure to GROalpha. Significant differences between GRObeta [5-73], GROalpha and interleukin-8 are in the N-terminal loop comprising residues 12 to 19. The N-terminal arm containing the conserved ELR motif and the loop of residues 30 to 38 containing the GPH motif are different among these three CXC chemokines. The structural differences in these two regions may be responsible for the specificity of the receptor binding and biological activity of different chemokines.
Assuntos
Quimiocinas CXC/química , Fatores Quimiotáticos/química , Substâncias de Crescimento/química , Peptídeos e Proteínas de Sinalização Intercelular , Interleucina-8/química , Ressonância Magnética Nuclear Biomolecular , Fragmentos de Peptídeos/química , Motivos de Aminoácidos , Medula Óssea , Linhagem Celular , Quimiocina CXCL1 , Quimiocina CXCL2 , Sequência Conservada , Cristalografia por Raios X , Dimerização , Dissulfetos/metabolismo , Humanos , Modelos Moleculares , Estrutura Secundária de Proteína , Deleção de Sequência , Soluções , Eletricidade Estática , Células Estromais , Relação Estrutura-AtividadeRESUMO
PURPOSE: Because a low IQ score indicates global brain damage, several authors consider it a contraindication for resective epilepsy surgery. This study reports the postoperative results of a small group of subaverage-intelligence patients with epilepsy who underwent focal resections. METHODS: We report on 16 patients who underwent focal resections (no callosotomy or hemispherectomy). All had IQ's <85 and were >13 years of age at the time of surgery. Low IQ was psychometrically assessed (mean IQ = 70) and confirmed by the patients' educational/occupational status. Clinical characteristics, findings from the preoperative workup, and the surgical treatment are described in detail. Postoperative outcome was evaluated with respect to seizure relief and cognitive/ socioeconomic development. RESULTS: Three months after surgery, 14 (87%) of 16 patients were completely seizure free, and nine (64%) of 14 were seizure free at the 1-year follow-up. Patients' cognitive abilities and socioeconomic status were mostly unchanged and in some cases improved. Seizure outcome was not related to IQ level, and there was no evidence of multiple epileptic foci in the patients with continued seizures. CONCLUSIONS: A low IQ level does not entail the presence of extended epileptogenic regions or multiple epileptic foci. Seizure-relief rates in our group concurred with the rates in patients of average intelligence, and the cognitive/socioeconomic outcome was favorable. We conclude that focal surgery in intellectually impaired patients can be recommended if the preoperative diagnostics confirm a circumscribed seizure onset.
Assuntos
Encéfalo/cirurgia , Epilepsias Parciais/cirurgia , Deficiência Intelectual/epidemiologia , Adolescente , Adulto , Encéfalo/patologia , Comorbidade , Epilepsias Parciais/diagnóstico , Epilepsias Parciais/epidemiologia , Feminino , Humanos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Masculino , Testes Neuropsicológicos , Resultado do TratamentoRESUMO
Two human CC chemokines, SLC/6Ckine/Exodus2/TCA4 and CKbeta-11/MIP-3beta/ELC, are previously reported as efficacious chemoattractants for T- and B-cells and dendritic cells. SLC and CKbeta-11 share only 32% amino acid identity, but are ligands for the same chemokine receptor, CCR7. In this study, we examined chemotactic activity of SLC and CKbeta-11 for NK cells and lymphoid progenitors in bone marrow and thymus. It was found that these two CCR7 ligands are chemoattractants for neonatal cord blood and adult peripheral blood NK cells and cell lines. SLC and CKbeta-11 preferentially attract the CD56(+)CD16(-) NK cell subset over CD56(+)CD16(+) NK cells. SLC and CKbeta-11 also demonstrate selective chemotactic activity on late stage CD34(-)CD19(+)IgM- B-cell progenitors and CD4(+) and CD8(+) single-positive thymocytes, but not early stage progenitors. It was noted that SLC is an efficient desensitizer of CKbeta-11-dependent NK cell chemotaxis, while CKbeta-11 is a weak desensitizer of SLC-dependent chemotaxis. Taken together, these results suggest that SLC and CKbeta-11 have the potential to control trafficking of NK cell subsets and late stage lymphoid progenitors in bone marrow and thymus.
Assuntos
Quimiocinas CC/metabolismo , Quimiotaxia de Leucócito , Células-Tronco Hematopoéticas/fisiologia , Células Matadoras Naturais/fisiologia , Receptores de Quimiocinas/metabolismo , Antígeno CD56/isolamento & purificação , Polaridade Celular , Quimiocina CCL19 , Quimiocina CCL21 , Citotoxicidade Imunológica , Exocitose , Humanos , Ligantes , Subpopulações de Linfócitos/fisiologia , Ligação Proteica , Receptores CCR7 , Receptores de IgG/isolamento & purificação , Timo/citologiaRESUMO
CBA mice were exposed outdoors to 50 Hz electromagnetic fields (EMF), with a flux density of about 8 microT rms (root mean square), generated by a 220 kV transmission line. Assays were performed in order to investigate, the possible genotoxic effects after 11, 20 and 32 days of exposure, as well as the effects on body weight, leukocytes, erythrocytes, and the level of ornithine decarboxylase (ODC) activity in spleen and testis. DNA migration was studied on brain cells by single cell electrophoresis (comet assay). After 32 days of exposure a highly significant change of the tail/head ratio of the comets was observed (p < 0.001), showing DNA-damage. Further, a decreased number of mononuclear leukocytes (0.02 < p < 0.05) was observed in mice EMF-exposed for 20 days. In summary, our data indicate that transmission lines of this type may induce genotoxic effects in mice, seen as changes in the DNA migration. These results might have an important implication for health effects.