Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 106
Filtrar
1.
Sci Rep ; 11(1): 10072, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980902

RESUMO

Twenty-four palaeogenomes from Mokrin, a major Early Bronze Age necropolis in southeastern Europe, were sequenced to analyse kinship between individuals and to better understand prehistoric social organization. 15 investigated individuals were involved in genetic relationships of varying degrees. The Mokrin sample resembles a genetically unstructured population, suggesting that the community's social hierarchies were not accompanied by strict marriage barriers. We find evidence for female exogamy but no indications for strict patrilocality. Individual status differences at Mokrin, as indicated by grave goods, support the inference that females could inherit status, but could not transmit status to all their sons. We further show that sons had the possibility to acquire status during their lifetimes, but not necessarily to inherit it. Taken together, these findings suggest that Southeastern Europe in the Early Bronze Age had a significantly different family and social structure than Late Neolithic and Early Bronze Age societies of Central Europe.


Assuntos
Relações Familiares , Genética Populacional , Genoma Humano , Hereditariedade , Distância Psicológica , Classe Social/história , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Seguimentos , História Antiga , Migração Humana , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida , Adulto Jovem
2.
Clin Breast Cancer ; 19(6): e731-e740, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31522958

RESUMO

Atrophic vaginitis is a relatively common adverse effect of aromatase inhibitors used as an adjunctive treatment for breast cancer. Vaginal estrogen therapy is a treatment option, but the safety of its use in estrogen receptor-positive breast cancer remains understudied. The aim of our study was to determine the safety of local hormonal treatment of vulvovaginal atrophy in women treated with aromatase inhibitors. Our meta-analysis was based on a systematic search of the literature and selection of high-quality evidence. The safety of local hormonal therapy of vaginal atrophy in women on aromatase inhibitors were summarized using calculators built by the authors; heterogeneity was assessed by the Cochrane Q test and I2 values. Several types of bias were assessed; publication bias was calculated by a funnel plot and the Egger regression. Eleven studies fulfilled the inclusion criteria for our study. After 8 weeks of local hormonal treatment, there was no change in the serum levels of luteinizing hormone and estradiol, whereas sex hormone binding globulins were low, and follicle stimulating hormone was almost doubled compared with the baseline. Adverse effect rates of vaginal discharge, facial hair growth, urinary tract or yeast infection, and vaginal or vulvar itching and/or irritation did not show significant changes in the sensitivity analysis, with exception of a single trial. Current evidence suggests that vaginal estrogen administration in postmenopausal women with a history of breast cancer is not associated with systemic absorption of sex hormones and may provide indirect evidence for the safety of their use.


Assuntos
Inibidores da Aromatase/efeitos adversos , Atrofia/tratamento farmacológico , Neoplasias da Mama/tratamento farmacológico , Terapia de Reposição Hormonal/métodos , Receptores de Estrogênio/metabolismo , Doenças Vaginais/tratamento farmacológico , Doenças da Vulva/tratamento farmacológico , Atrofia/induzido quimicamente , Atrofia/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Humanos , Prognóstico , Doenças Vaginais/induzido quimicamente , Doenças Vaginais/patologia , Doenças da Vulva/induzido quimicamente , Doenças da Vulva/patologia
3.
Acta Neuropathol Commun ; 6(1): 18, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29490700

RESUMO

Despite multidisciplinary local and systemic therapeutic approaches, the prognosis for most patients with brain metastases is still dismal. The role of adaptive and innate anti-tumor response including the Human Leukocyte Antigen (HLA) machinery of antigen presentation is still unclear. We present data on the HLA class II-chaperone molecule CD74 in brain metastases and its impact on the HLA peptidome complexity.We analyzed CD74 and HLA class II expression on tumor cells in a subset of 236 human brain metastases, primary tumors and peripheral metastases of different entities in association with clinical data including overall survival. Additionally, we assessed whole DNA methylome profiles including CD74 promoter methylation and differential methylation in 21 brain metastases. We analyzed the effects of a siRNA mediated CD74 knockdown on HLA-expression and HLA peptidome composition in a brain metastatic melanoma cell line.We observed that CD74 expression on tumor cells is a strong positive prognostic marker in brain metastasis patients and positively associated with tumor-infiltrating T-lymphocytes (TILs). Whole DNA methylome analysis suggested that CD74 tumor cell expression might be regulated epigenetically via CD74 promoter methylation. CD74high and TILhigh tumors displayed a differential DNA methylation pattern with highest enrichment scores for antigen processing and presentation. Furthermore, CD74 knockdown in vitro lead to a reduction of HLA class II peptidome complexity, while HLA class I peptidome remained unaffected.In summary, our results demonstrate that a functional HLA class II processing machinery in brain metastatic tumor cells, reflected by a high expression of CD74 and a complex tumor cell HLA peptidome, seems to be crucial for better patient prognosis.


Assuntos
Antígenos CD/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/secundário , Genes MHC da Classe II , Sialiltransferases/metabolismo , Antígenos CD/genética , Biomarcadores Tumorais/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/mortalidade , Linhagem Celular Tumoral , Estudos de Coortes , Metilação de DNA , Técnicas de Silenciamento de Genes , Humanos , Estimativa de Kaplan-Meier , Melanoma/metabolismo , Melanoma/patologia , Prognóstico , Regiões Promotoras Genéticas , Sialiltransferases/genética , Linfócitos T/metabolismo , Linfócitos T/patologia
4.
Mol Ecol ; 26(20): 5484-5499, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28833842

RESUMO

Range and niche expansion are commonly associated with transitions to asexuality, polyploidy and hybridity (allopolyploidy) in plants. The ability of asexual polyploids to colonize novel habitats may be due to widespread generalist clones, multiple ecologically specialized clones, or may be a neutral by-product of multiple, independent origins of asexual polyploids throughout the range. We have quantified niche size and divergence for hawthorns of the Pacific Northwest using data from herbarium vouchers with known cytotypes. We find that all polyploid niches diverge from that of the diploid range, and allopolyploids have the broadest niches. Allotetraploids have the largest niche and the widest geographic distribution. We then assessed the genetic mechanism of range expansion by surveying the ecological and geographic distribution of genotypes within each cytotype from sites in which fine-scale habitat assessments were completed. We find no isolation by either geographic or ecological distance in allopolyploids, suggesting high dispersal and colonization ability. In contrast, autotriploids and diploids show patterns of isolation by geographic distance. We also compared the geographic and ecological distributions of clonal genotypes with those of randomly drawn sites of the most widespread cytotype. We found that most clones are geographically widespread and occur in a variety of habitats. We interpret these findings to suggest that patterns of range and niche expansion in Pacific Northwest Hawthorns may stem from these widespread, ecologically generalist clones of hybrid origin.


Assuntos
Crataegus/genética , Ecossistema , Genética Populacional , Poliploidia , Crataegus/fisiologia , DNA de Plantas/genética , Diploide , Variação Genética , Genótipo , Geografia , Repetições de Microssatélites , Noroeste dos Estados Unidos , Dispersão Vegetal , Reprodução Assexuada
5.
Hippokratia ; 20(1): 44-49, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27895442

RESUMO

BACKGROUND: Medical Fear Survey (MFS) is an instrument designed for measuring fear of medical and related treatments. OBJECTIVE: Aim of the present study was MFS translation into Serbian, measurement of its psychometric properties and MFS validation using other Blood-injury-injections and related stimuli instruments that have been translated from English into Serbian. METHOD: After obtaining permission from the author of the original MFS, double forward translation from English to Serbian and backward translation to English were conducted in ten steps, according to International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines. Reliability, factorial analysis and concurrent validation of Serbian version of MFS were conducted on a sample of 485 medical or pharmacy students at University of Kragujevac, Serbia. RESULTS: Serbian version of MFS showed high internal consistency with a Cronbach's alpha 0.968 and good temporal stability after testing-and-retesting (Spearman's correlation coefficient 0.838, and intraclass correlation coefficient 0.877). Factorial analysis confirmed the same five factors demonstrated in the original English version: fear of mutilated bodies (10 items), fear of blood (11 items), fear of injections and blood draws (9 items), fear of sharp objects (10 items), and fear of medical examinations and physical symptoms (10 items). The total score of MFS correlated significantly with the total scores of Injection Phobia Scale-Anxiety (Spearman's correlation coefficient 0.391, p <0.001), Blood/Injection Fear Scale (Spearman's correlation coefficient 0.502, p <0.001) and Medical Avoidance Survey (Spearman's correlation coefficient 0.396, p <0.001). CONCLUSIONS: Serbian version of the 50-item MFS showed similar psychometric properties as the original English version of this scale, with the same factorial structure. It could be used for measurement of fear of medical and related treatments in Serbian socio-cultural milieu, preferably self-administered. Hippokratia 2016, 20(1): 44-49.

6.
Ann Bot ; 114(2): 253-69, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24984714

RESUMO

BACKGROUND AND AIMS: The taxonomic complexity of Crataegus (hawthorn; Rosaceae, Maleae), especially in North America, has been attributed by some to hybridization in combination with gametophytic apomixis and polyploidization, whereas others have considered the roles of hybridization and apomixis to be minimal. Study of the chemical composition and therapeutic value of hawthorn extracts requires reproducible differentiation of entities that may be difficult to distinguish by morphology alone. This study sought to address this by using the nuclear ribosomal spacer region ITS2 as a supplementary DNA barcode; however, a lack of success prompted an investigation to discover why this locus gave unsatisfactory results. METHODS: ITS2 was extensively cloned so as to document inter- and intraindividual variation in this locus, using hawthorns of western North America where the genus Crataegus is represented by only two widely divergent groups, the red-fruited section Coccineae and the black-fruited section Douglasia. Additional sequence data from selected loci on the plastid genome were obtained to enhance further the interpretation of the ITS2 results. KEY RESULTS: In the ITS2 gene tree, ribotypes from western North American hawthorns are found in two clades. Ribotypes from diploid members of section Douglasia occur in one clade (with representatives of the east-Asian section Sanguineae). The other clade comprises those from diploid and polyploid members of section Coccineae. Both clades contribute ribotypes to polyploid Douglasia. Data from four plastid-derived intergenic spacers demonstrate the maternal parentage of these allopolyploids. CONCLUSIONS: Repeated hybridization between species of section Douglasia and western North American members of section Coccineae involving the fertilization of unreduced female gametes explains the observed distribution of ribotypes and accounts for the phenetic intermediacy of many members of section Douglasia.


Assuntos
Evolução Biológica , Núcleo Celular/genética , Crataegus/genética , DNA Espaçador Ribossômico/genética , Frutas/genética , Plastídeos/genética , Sequência de Bases , Variação Genética , Hibridização Genética , Modelos Biológicos , América do Norte , Conformação de Ácido Nucleico , Filogenia , Poliploidia , Especificidade da Espécie
7.
J Med Genet ; 51(2): 90-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24253444

RESUMO

BACKGROUND: The T gene (brachyury gene) is the founding member of the T-box family of transcription factors and is vital for the formation and differentiation of the mesoderm and the axial development of all vertebrates. RESULTS: We report here on four patients from three consanguineous families exhibiting sacral agenesis, a persistent notochordal canal and abnormal ossification of the vertebral bodies, and the identification and characterisation of their underlying genetic defect. Given the consanguineous nature and the similarity of the phenotypes between the three families, we performed homozygosity mapping and identified a common 4.1 Mb homozygous region on chromosome 6q27, containing T, brachyury homologue (mouse) or T. Sequencing of T in the affected individuals led to the identification of a homozygous missense mutation, p.H171R, in the highly conserved T-box. The homozygous mutation results in diminished DNA binding, increased cell growth, and interferes with the normal expression of genes involved in ossification, notochord maintenance and axial mesoderm development. CONCLUSIONS: We have identified a shared homozygous mutation in three families in T and linked it to a novel syndrome consisting of sacral agenesis, a persistent notochordal canal and abnormal ossification of the vertebral bodies. We suggest that screening for the ossification of the vertebrae is warranted in patients with sacral agenesis to evaluate the possible causal involvement of T.


Assuntos
Anormalidades Múltiplas/genética , Proteínas Fetais/genética , Notocorda/anormalidades , Ossificação Heterotópica/genética , Sacro/anormalidades , Coluna Vertebral/anormalidades , Proteínas com Domínio T/genética , Anormalidades Múltiplas/diagnóstico por imagem , Anormalidades Múltiplas/mortalidade , Sequência de Aminoácidos , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células , Cromossomos Humanos Par 6/genética , Hibridização Genômica Comparativa , Consanguinidade , Feminino , Estudos de Associação Genética , Homozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Mutação de Sentido Incorreto , Notocorda/diagnóstico por imagem , Ossificação Heterotópica/diagnóstico por imagem , Ossificação Heterotópica/mortalidade , Linhagem , Ligação Proteica , Transporte Proteico , Sacro/diagnóstico por imagem , Coluna Vertebral/diagnóstico por imagem , Síndrome , Ultrassonografia Pré-Natal
8.
Br Poult Sci ; 54(4): 515-23, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23819612

RESUMO

1. The objective of this study was to investigate in vitro and in vivo (in broiler chickens) ochratoxin A (OTA) adsorption efficiency of three different adsorbents: inorganic (modified zeolite); organic (esterified glucomannans) and mixed (inorganic and organic components plus enzymes). 2. The aim of the study was to investigate which of these adsorbents provided the best protection against the presence of residues of OTA in the pectoral muscle and liver of broilers given an OTA-contaminated diet. In addition, it was important to test and compare the results of adsorbent efficiency using two different in vitro methods. 3. The results from classical in vitro investigations carried out in the artificial intestinal fluid, showed that the inorganic adsorbent (Mz), exhibited the highest adsorption, having adsorbed 80.86 ± 1.85% of OTA, whereas average in vitro adsorption abilities of organic (30.52 ± 3.50%) and mixed (32.00 ± 2.60%) adsorbents were significantly lower. 4. In the investigation of absorption in everted sacs of broiler duodenal segments (Everted Duodenal Sacs Procedure), higher OTA adsorption in gut was exhibited by organic adsorbent, 74.26 ± 4.48%. Furthermore, the mean adsorption efficiency of mixed and inorganic adsorbent was 65.26 ± 4.76% and 45.75 ± 7.14%, respectively. 5. In the in vivo investigation, broilers were fed for 21 d on diets containing 2 mg/kg of OTA and supplemented with inorganic (Mz), organic (Ms) or mixed adsorbent (Mf) at the recommended concentration of 2 g/kg of feed. All three adsorbents significantly decreased OTA residue concentrations in the pectoral muscle and livers, but the order of effectiveness was mixed > organic > inorganic. The most efficient was the mixed adsorbent which decreased residue concentration by 72.50% in pectoral muscle and 94.47% in livers. 6. The Everted Duodenal Sac in vitro method provided results similar to those obtained in the in vivo study. However, further studies are required to investigate the efficiencies of adsorbents against various mycotoxins using this method.


Assuntos
Galinhas/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Mananas/farmacologia , Ocratoxinas/metabolismo , Zeolitas/farmacologia , Adsorção , Ração Animal/análise , Animais , Galinhas/microbiologia , Cromatografia Líquida de Alta Pressão/veterinária , Dieta/veterinária , Suplementos Nutricionais/análise , Enzimas/metabolismo , Esterificação , Feminino , Contaminação de Alimentos/análise , Técnicas In Vitro , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/microbiologia , Masculino , Mananas/administração & dosagem , Músculos Peitorais/efeitos dos fármacos , Músculos Peitorais/metabolismo , Músculos Peitorais/microbiologia , Zeolitas/administração & dosagem
9.
Physiol Res ; 60(6): 933-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21995893

RESUMO

The aim of our study was to investigate mechanism of action of endothelins 1, 2 and 3 on spontaneous activity, tone and intraluminal pressure of human ureter. Both longitudinal tension and intraluminal pressure were recorded from the isolated segments of proximal human ureter. Endothelins 1, 2 and 3 (5.35x10(-11) M - 5.05x10(-8) M) produced concentration-dependent tonic contraction and sustained increase in intraluminal pressure of isolated preparations of human ureter. Endothelins 1 and 3 produced also concentration-dependent inhibition of spontaneous, phasic contractions of the isolated preparations. Selective antagonist of ET(A) receptors BQ123 and selective antagonist of ET(B) receptors BQ788 produced significant inhibition of endothelin-1-induced tonic contraction (pA(2)=8.80 and 6.55, respectively) and increase in intraluminal pressure (pA(2)=8.68 and 7.02, respectively), while they did not affect endothelin-1-induced inhibition of spontaneous activity. Endothelin 1 produces increase in tone and intraluminal pressure of isolated human ureter acting on both ET(A) and ET(B) receptors, the first one being functionally more important. Only endothelins 1 and 3 inhibit spontaneous, phasic activity of human ureter, but this effect was not blocked by selective antagonists of ET(A) and ET(B) receptors.


Assuntos
Endotelinas/farmacologia , Ureter/efeitos dos fármacos , Idoso , Antagonistas dos Receptores de Endotelina , Endotelina-1/farmacologia , Endotelina-1/fisiologia , Endotelina-2/farmacologia , Endotelina-2/fisiologia , Endotelina-3/farmacologia , Endotelina-3/fisiologia , Endotelinas/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Receptores de Endotelina/fisiologia , Ureter/fisiologia
11.
Acta Chir Iugosl ; 56(2): 81-6, 2009.
Artigo em Sérvio | MEDLINE | ID: mdl-19780335

RESUMO

OBJECTIVES: The aim of the study was to analyze the epidemiological and microbiological analysis of surgical site infections in the orthopedic wards. MATERIALS AND METHODS: A 6-month prospective cohort study was conducted at the major teaching hospital in Belgrade. Patient's basic demographic data and data about surgical site infections were collected. Bacteria cultured from the surgical site were also analyzed. RESULTS: A total of 277 patients operated in the Institute of Orthopedics and trauma surgery, Clinical Center of Serbia. Sixty-three cases of SSI were detected, and the overall incidence rate was 22.7% (95% IP = 17.8-27.6). Fifty-three (84.1%) SSIs had microbiological confirmation and overall 82 bacterial strains were isolated. The most frequent isolated bacteria were Staphylococcus aureus, Acinetobacter sp, Klebsiella pp, Pseudomonas sp and Enterococcus sp. Nineteen (79.2%) strains of Staphylococcus aureus isolated from infected surgical sites were meticillin- resistant. CONCLUSION: This study suggests that it is necessary to maintain continuous surveillance of surgical site infections. It is important to emphasize the need for implementation the measures of contact isolation in order to prevent the nosocomial transmission of resistant bacteria.


Assuntos
Procedimentos Ortopédicos , Infecção da Ferida Cirúrgica/microbiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Farmacorresistência Bacteriana , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Infecção da Ferida Cirúrgica/diagnóstico , Adulto Jovem
13.
Acta Chir Iugosl ; 55(2): 27-31, 2008.
Artigo em Sérvio | MEDLINE | ID: mdl-18792570

RESUMO

Between April 1989 and September 2007, 181 patients with disease of lower cranial nerves (DLCN) underwent posterior fossa exploration. As a cause of DLCN, vascular compression (VC) was present in 89 patients with trigeminal neuralgia (TN), in 6 with hemifacial spasm (HFS), in 1 with glossopharyngeal neuralgia, in 1 with Meniere's disease, and in 5 with multiple DLCN. Depending on intraoperative findings, different surgical options were used: microvascular decompression (MVD), MVD with partial sensory rhizotomy (PSR) or total sensory rhizotomy (TSR). Statistic analysis was made using the Fisher's exact 2-side test. In patients with TN, excellent outcome was archived in 83 patients and good in 6. Postoperative outcome was better (p = 0.007) in cases with severe VC, but without significant correlation between used surgical option and outcome (p = 0.402). Frequency rate of relapses did not depend on severity of VC (p = 0.502) and used surgical option (p = 0.175). In 6 patients with HFS, excellent outcome was archived in 5 with arterial compression and poor in 1 with venous contact. In patients with Meniere's disease and glossopharyngeal neuralgia, MVD result with excellent outcome. In 5 patients with multiple DLCN, excellent outcome was archived in 3 and good in 2. MVD is method of choice in surgical treatment of DLCN caused by VC. Overall outcome is better with severity of VC.


Assuntos
Artérias Cerebrais/patologia , Síndromes de Compressão Nervosa/cirurgia , Adulto , Idoso , Descompressão Cirúrgica , Feminino , Doenças do Nervo Glossofaríngeo/etiologia , Doenças do Nervo Glossofaríngeo/cirurgia , Espasmo Hemifacial/etiologia , Espasmo Hemifacial/cirurgia , Humanos , Masculino , Doença de Meniere/etiologia , Doença de Meniere/cirurgia , Pessoa de Meia-Idade , Síndromes de Compressão Nervosa/etiologia , Procedimentos Neurocirúrgicos
15.
J Colloid Interface Sci ; 284(1): 48-56, 2005 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-15752783

RESUMO

The paper presents results of investigation of exchange of the clinoptilolite tuff cations with hydrogen ions from HCl solution of concentration 0.1 mmol cm(-3) and ammonium ions solutions of concentrations 0.0071 to 2.6 mmol cm(-3). Molal concentrations, x (mmol g(-1)) of cations exchanged in acid solution and in ammonium ions solutions were compared with molal concentrations of cations obtained by determination of the cation-exchange capacity of clinoptilolite tuff. The obtained results show that at ammonium ion concentrations lower than 0.1 mmol cm(-3), with regard to exchange capacity for particular ions, best exchanged are Na+ ions, followed by Mg2+ and Ca2+ ions, while exchange of K+ ions is the poorest (Na+ > Mg2+ > Ca2+ > K+). At ammonium concentrations from 0.2 to 1 mmol cm(-3) the order is Na+ > Ca2+ > Mg2+ > K+. At concentrations higher than 1 mmol cm(-3) the order is Na+ > Ca2+ > K+ > Mg2+. The results are a consequence of the uptake of hydrogen ions by zeolite samples in ammonium ions solutions at concentrations lower than 1 mmol cm(-3) and indicate the importance of Mg2+ (besides Na+ ions) for the exchange between clinoptilolite cations and H+ ions, in contrast to K+ ions, whose participation in the reaction with H+ ions is the lowest. During decationization of the clinoptilolite in acid solution, best exchanged are Na+, Mg2+, and Ca2+ ions, while exchange of K+ ions is the poorest. Due to poor exchange of K+ and H+ ions and good exchange of Na+, Mg2+, and Ca2+ ions, it is to be assumed that preservation of stability of the clinoptilolite structure is caused by K+ ions present in the channel C. Clinoptilolite is dissolved in the clinoptilolite A and B channels where Na+, Mg2+, and Ca2+ ions are present. On the acid-modified clinoptilolite samples, exchange of ammonium ions is poorer than on natural zeolite. The longer the contact time of the zeolite and acid solution, the worse ammonium ions exchange. It can be assumed that H+ ions exchanged with zeolite cations are consumed for solution of aluminum in the clinoptilolite structure; therefore the concentration of H+ ions as exchangeable cations decreases. In the ammonium ion solution at a concentration of 0.0065 mmol cm(-3), from the acid-modified zeolite samples, Al3+ ions are exchanged best, followed by Na+, Mg2+, Ca2+, and K+ ions. Further to the results, it is to be assumed that exchangeable Al3+ ions available from clinoptilolite dissolution are best exchanged with H+ ions in acid solution.

16.
Biogerontology ; 2(1): 19-34, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11708614

RESUMO

In Alzheimer's disease, age-related cellular changes such as compromised energy production and increased radical formation are worsened by the presence of AGEs as additional, AD specific stress factors. Intracellular AGEs (most likely derived from methylglyoxal) crosslink cytoskeletal proteins and render them insoluble. These aggregates inhibit cellular functions including transport processes and contribute to neuronal dysfunction and death. Extracellular AGEs, which accumulate in ageing tissue (but most prominently on long-lived protein deposits like the senile plaques) exert chronic oxidative stress on neurons. In addition, they activate glial cells to produce free radicals (superoxide and NO) and neurotoxic cytokines such as TNF-alpha. Drugs, which inhibit the formation of AGEs by specific chemical mechanisms (AGE-inhibitors), including aminoguanidine, carnosine, tenilsetam, OPB-9195 and pyridoxamine, attenuate the development of (AGE-mediated) diabetic complications. Assuming that 'carbonyl stress' contributes significantly to the progression of Alzheimer's disease, AGE-inhibitors might also become interesting novel therapeutic drugs for treatment of AD.


Assuntos
Envelhecimento/metabolismo , Doença de Alzheimer/tratamento farmacológico , Encéfalo/metabolismo , Produtos Finais de Glicação Avançada/antagonistas & inibidores , Fármacos Neuroprotetores/farmacologia , Animais , Demência/tratamento farmacológico , Produtos Finais de Glicação Avançada/metabolismo , Humanos , Transdução de Sinais
17.
Brain Res ; 920(1-2): 32-40, 2001 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-11716809

RESUMO

Advanced glycation endproducts (AGEs), protein-bound oxidation products of sugars, have been shown to be involved in the pathophysiological processes of Alzheimer's disease (AD). AGEs induce the expression of various pro-inflammatory cytokines and the inducible nitric oxide synthase (iNOS) leading to a state of oxidative stress. AGE modification and resulting crosslinking of protein deposits such as amyloid plaques may contribute to the oxidative stress occurring in AD. The aim of this study was to immunohistochemically compare the localization of AGEs and beta-amyloid (Abeta) with iNOS in the temporal cortex (Area 22) of normal and AD brains. In aged normal individuals as well as early stage AD brains (i.e. no pathological findings in isocortical areas), a few astrocytes showed co-localization of AGE and iNOS in the upper neuronal layers, compared with no astrocytes detected in young controls. In late AD brains, there was a much denser accumulation of astrocytes co-localized with AGE and iNOS in the deeper and particularly upper neuronal layers. Also, numerous neurons with diffuse AGE but not iNOS reactivity and some AGE and iNOS-positive microglia were demonstrated, compared with only a few AGE-reactive neurons and no microglia in controls. Finally, astrocytes co-localized with AGE and iNOS as well as AGE and were found surrounding mature but not diffuse amyloid plaques in the AD brain. Our results show that AGE-positive astrocytes and microglia in the AD brain express iNOS and support the evidence of an AGE-induced oxidative stress occurring in the vicinity of the characteristic lesions of AD. Hence activation of microglia and astrocytes by AGEs with subsequent oxidative stress and cytokine release may be an important progression factor in AD.


Assuntos
Doença de Alzheimer/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Óxido Nítrico Sintase/metabolismo , Idoso , Doença de Alzheimer/enzimologia , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Indução Enzimática/fisiologia , Feminino , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Masculino , Microglia/metabolismo , Óxido Nítrico Sintase/biossíntese , Óxido Nítrico Sintase Tipo II , Placa Amiloide/enzimologia , Placa Amiloide/patologia , Lobo Temporal/metabolismo , Lobo Temporal/patologia , Inclusão do Tecido
18.
Pharmazie ; 56(10): 803-7, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11683128

RESUMO

Eight novel N-heteroarylalkyl-N-phenylpiperazines have been synthesized, chemically characterized and evaluated for in vitro binding affinity at the dopamine and serotonin receptors. Synaptosomal membranes of fresh bovine caudate nuclei (D1 and D2), the membranes of COS-7 cells (D4.4) and those prepared from fresh bovine hippocampi (5-HT1A) were used as a source of the corresponding receptor subtypes. [3H]SCH 23390 (D1-selective), [3H]spiperone (D2- and D4.4-selective) and [3H]-8-OH-DPAT (5-HT1A-selective) served as radioligands. None of the compounds expressed the affinity for the binding at the D1 subtype receptor. Compounds 7-9 containing a single methylene group serving as a bridge between heteroaryl- and N-phenylpiperazine part of the molecule were inactive [3H]spiperone and [3H]-8-OH-DPAT competitors. Ligands 15-19 (three methylene groups connecting heteroaryl- and N-phenylpiperazine part of the molecule) acted as moderate competitors of [3H]spiperone binding at the D2 receptor subtype, with the exception of 15 (a thione) which expressed a high binding affinity at the D2 receptor subtype. Compounds 15-19 behaved as moderate displacers of 8-OH-[3H]DPAT. Among all eight novel ligands only compound 15 expressed a moderate binding affinity at the D4.4 receptor subtype.


Assuntos
Dopaminérgicos/síntese química , Piperazinas/síntese química , Piperazinas/farmacologia , Receptores de Dopamina D2/efeitos dos fármacos , Receptores de Serotonina/efeitos dos fármacos , Serotoninérgicos/síntese química , 8-Hidroxi-2-(di-n-propilamino)tetralina/farmacologia , Animais , Benzazepinas/farmacologia , Bovinos , Núcleo Caudado/efeitos dos fármacos , Núcleo Caudado/metabolismo , Dopaminérgicos/farmacologia , Antagonistas de Dopamina/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Humanos , Técnicas In Vitro , Receptores 5-HT1 de Serotonina , Proteínas Recombinantes/metabolismo , Serotoninérgicos/farmacologia , Agonistas do Receptor de Serotonina/farmacologia , Relação Estrutura-Atividade , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo
19.
Water Res ; 35(14): 3436-40, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11547865

RESUMO

An evaluation of the application of electric furnace slag (EFS) as an adsorbent to remove Pb2+ and Cu2+ from industrial effluents is presented. The paper examines phase composition of EFS by using X-ray diffraction of powder. In the batch experiments, parameters studied include the effect of initial concentration of lead and copper ions, temperature, and contact time. Over the temperature range studied (293-313 K) the results of adsorption experiments could be fitted by using both Langmuir and Freundlich models and thermodynamic values of deltaG0, deltaH0 and deltaS0 corresponding to each adsorption process were calculated. Satisfactory conformity between experimental data and the model-predicted values was expressed by the correlation coefficient (R2). Both Langmuir and Freundlich models described the Pb2+ and Cu2+ sorption processes adequately, with correlation coefficient (R2) values ranging from 0.9760 to 0.9994. Data from this study indicated the potential use of the tested electric furnace slag, a by-product from "Felis" foundry in Sisak, Croatia, as Pb2+ and Cu2+ sorbents from the industrial effluents.


Assuntos
Cobre/isolamento & purificação , Chumbo/isolamento & purificação , Purificação da Água/métodos , Adsorção , Conservação dos Recursos Naturais , Cobre/química , Resíduos Industriais , Cinética , Chumbo/química , Termodinâmica , Poluição Química da Água , Difração de Raios X
20.
J Chromatogr A ; 918(2): 325-34, 2001 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-11407579

RESUMO

A non-suppressed ion chromatographic method with conductometric detection is described for the simultaneous determination of six inorganic anions: fluoride, chloride, nitrite, bromide, nitrate and sulphate. The separation was achieved on a low-capacity anion-exchange column Metrohm IC Anion Column Super Sep, with a mobile phase consisting of phtalic acid dissolved in high-purity water, 2-amino-2-hydroxymethyl-1,3-propendiol and acetonitrile. In this work computer optimization procedures, using computer programs to select chromatographic conditions have been used, leading to the achievement of a desired separation. By using the different optimization methods in an integrated manner it is, however, possible to both speed method development, by reducing unnecessary experimentation, and to overcome the many shortcomings of each method, because of the different approaches. The purpose of this work is to improve and characterise the method for simultaneous determination of six inorganic anions in drinking water by non-suppressed ion chromatography, using optimization procedures, in order to be applied to the routine analysis. The proposed method has numerous advantages over the other widely used non-suppressed ion chromatography methods: higher selectivity, shorter analysis time, lower quantitation and detection limits. The performance characteristics of the method were established by determining the following validation parameters: precision and accuracy, linearity, detection limits and quantitation limits.


Assuntos
Ânions/análise , Cromatografia Líquida/métodos , Compostos Inorgânicos/análise , Abastecimento de Água/análise , Calibragem , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...