RESUMO
Microbial volatiles are important factors in symbiotic interactions with plants. Mortierella hyalina is a beneficial root-colonizing fungus with a garlic-like smell, and promotes growth of Arabidopsis seedlings. GC-MS analysis of the M. hyalina headspace and NMR analysis of the extracted essential oil identified the sulfur-containing volatile tris(methylthio)methane (TMTM) as the major compound. Incorporation of the sulfur from the fungal volatile into plant metabolism was shown by 34S labeling experiments. Under sulfur deficiency, TMTM down-regulated sulfur deficiency-responsive genes, prevented glucosinolate (GSL) and glutathione (GSH) diminishment, and sustained plant growth. However, excess TMTM led to accumulation of GSH and GSL and reduced plant growth. Since TMTM is not directly incorporated into cysteine, we propose that the volatile from M. hyalina influences the plant sulfur metabolism by interfering with the GSH metabolism, and alleviates sulfur imbalances under sulfur stress.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Glutationa/metabolismo , Homeostase , Metano/metabolismo , Mortierella , Enxofre/metabolismoRESUMO
BACKGROUND: Osteoporosis is a common complication of Crohn's disease. AIM: To study the effect on the bone mineral density of a bisphosphonate (pamidronate) given intravenously, in combination with oral calcium and vitamin D supplements, compared with oral calcium and vitamin D supplements alone. METHODS: Seventy-four patients with Crohn's disease and low bone mineral density at the lumbar spine and/or hip were randomized to receive either a daily dose of 500 mg of calcium with 400 IU of vitamin D alone or in combination with four three-monthly infusions of 30 mg of intravenous pamidronate over the course of 12 months. The main outcome measure was the change in bone mineral density at the lumbar spine and hip, measured by dual X-ray absorptiometry, at baseline and 12 months. RESULTS: Both groups gained bone mineral density at the lumbar spine and hip after 12 months. There were significant (P < 0.05) changes in the pamidronate group, with gains of + 2.6%[95% confidence interval (CI), 1.4-3.0] at the spine and + 1.6% (95% CI, 0.6-2.5) at the hip, compared with gains of + 1.6% (95% CI, - 0.1-3.2) and + 0.9% (95% CI, - 0.4-2.1) at the spine and hip, respectively, in the group taking vitamin D and calcium supplements alone. CONCLUSIONS: In patients with Crohn's disease and low bone mineral density, intravenous pamidronate significantly increases the bone mineral density at the lumbar spine and hip.
Assuntos
Anti-Inflamatórios/administração & dosagem , Desmineralização Patológica Óssea/tratamento farmacológico , Cálcio/administração & dosagem , Doença de Crohn/complicações , Difosfonatos/administração & dosagem , Vitamina D/administração & dosagem , Administração Oral , Desmineralização Patológica Óssea/etiologia , Desmineralização Patológica Óssea/fisiopatologia , Desmineralização Patológica Óssea/urina , Densidade Óssea , Colágeno/urina , Colágeno Tipo I , Doença de Crohn/fisiopatologia , Doença de Crohn/urina , Método Duplo-Cego , Quimioterapia Combinada , Humanos , Infusões Intravenosas , Pamidronato , Peptídeos/urina , Resultado do TratamentoRESUMO
BACKGROUND: Osteoporosis is an important cause of morbidity in patients with Crohn's disease. The pathogenesis of reduced bone mineral density (BMD) is multifactorial. A range of genetic factors have been implicated in other populations of patients with osteoporosis. AIM: To investigate the influence of interleukin 6 (IL-6), collagen type 1alpha1 (COL1A1), and vitamin D receptor gene (VDR) single nucleotide polymorphisms (SNP) on BMD in patients with Crohn's disease. PATIENTS: A cohort of 245 well characterised patients with Crohn's disease were recruited from the inflammatory bowel disease register at the Freeman Hospital and Royal Victoria Infirmary, Newcastle upon Tyne, and the Queen Elizabeth Hospital, Gateshead, UK. METHODS: Patients were genotyped for IL-6 C-174G SNP, COL1A1 Sp1 binding site G T SNP, VDR Taq1, and Fok1 SNPs, and CARD15 R702W, G908R, and L1007fs SNPs. BMD was measured at the lumbar spine (LSP) and hip using dual energy x ray absorptiometry. RESULTS: A total of 158 female and 87 male patients, aged 24-70 years (mean 44), were recruited. There were no significant differences in the distribution of the tested SNPs when analysed for age, body mass index, pre/post-menopausal status, smoking, or steroid use. Two hundred and thirteen patients were genotyped for the IL-6 SNP. LSP and total hip BMD was significantly lower in patients with the GG genotype (48%) than the CC genotype (15%) (p = 0.041, p = 0.014). One hundred and eighty patients were genotyped for the COL1A1 SNP. There was no significant difference in BMD at LSP. Hip BMD was significantly lower in heterozygous patients compared with homozygous wild-types (p = 0.034). There were no significant differences in BMD between genotypes for the two VDR SNPs or the CARD15 genotypes examined. CONCLUSION: IL-6 and COL1A1 gene polymorphisms influence BMD in patients with Crohn's disease but the particular VDR gene polymorphisms studied do not have a major effect.
Assuntos
Densidade Óssea/genética , Colágeno Tipo I/genética , Doença de Crohn/genética , Interleucina-6/genética , Receptores de Calcitriol/genética , Corticosteroides/farmacologia , Adulto , Idoso , Densidade Óssea/efeitos dos fármacos , Cadeia alfa 1 do Colágeno Tipo I , Doença de Crohn/tratamento farmacológico , Doença de Crohn/fisiopatologia , Feminino , Genótipo , Articulação do Quadril/fisiopatologia , Humanos , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo ÚnicoRESUMO
In this report the role of the WHO Guidelines for Drinking Water Quality in promoting safe drinking water for the world's population is briefly described. The guidelines are being revised in a third edition to emphasize an integrated approach to water quality assessment and management from source to consumer. The forthcoming guidelines will: be risk-based and quantitative, emphasize quality protection and prevention of contamination, be proactive and participatory, and address the needs of those in developing countries who have no access to piped community water supplies. The guidelines emphasize the maintenance of microbial quality to prevent waterborne infectious disease as an essential goal. In addition, they address protection from chemical toxicants and other contaminants of public health concern. The forthcoming 3rd edition of the WHO GDWQ intend to be responsive to the under-served in developing countries by inclusion of non-piped supplies and addressing practical systems for their collection, treatment and storage at household level to provide safe water. Beyond the inclusion of these and possibly additional household water collection, treatment and storage systems, what is needed is to achieve their widespread use is an education and dissemination campaign that promotes and explains them and their benefits. Such a communication and marketing campaign is best done by including as many different sectors and stakeholders as possible in the process. It will be important to acknowledge that safe water is one of essential components or needs for healthy living, along with adequate sanitation and proper nutrition. Together, these are the essential health needs to be met in the developing and the developed world. All three contribute to reduced disease and increased health, and the lack of one can degrade the beneficial impact of the others. The importance of safe water, sanitation and nutrition to human health and well-being can be stated no better than it was by United Nations Secretary General Kofi Annan in his statement on "Freedom from Want" in the Millennium Report, 03/04/00. "How can we call human beings free and equal in dignity when over a billion of them are struggling to survive on less than one dollar a day, without safe drinking water, and when half of all humanity lacks adequate sanitation? Some of us are worrying about whether the stock market will crash, or struggling to master our latest computer, while more than half our fellow men and women have much more basic worries, such as where their children's next meal is coming from."
Assuntos
Saúde Pública , Saneamento/normas , Abastecimento de Água/normas , Qualidade de Produtos para o Consumidor , Ingestão de Líquidos , Guias como Assunto , Humanos , Saneamento/métodos , Microbiologia da Água , Organização Mundial da SaúdeRESUMO
The identification of the migrants, into food simulants, from a series of polyurethane adhesives used in the manufacture of plastic film laminates for use in common food packaging is described. Commercial materials, based on four different model adhesive systems, were prepared by an industrial collaborator. The MALDI-MS fingerprint patterns of the three polyether and one polyester polyol components of these adhesives were obtained for reference purposes. The decrease in the level of diisocyanate as a migrant versus time after lamination was confirmed by colorimetric measurements. The migration of the standard polyol samples through polyethylene pouches into water at 70 degrees C has been demonstrated and also the attenuation effect for different polyols. Cured laminates in the form of pouches were used to carry out the migration experiments into distilled water, inside the pouch, at 70 degrees C over a period of 2 h. Comparison of the migration results from the food packaging laminates with those from the polyethylene film confirmed the migration of unreacted polyol components for the polyether-based systems. Cyclic oligomers from the polyol starting materials were identified as the migrants from the polyester-based adhesive.
Assuntos
Cianatos/análise , Contaminação de Alimentos/análise , Embalagem de Alimentos , Poliuretanos/análise , Colorimetria , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Originally discovered in the bacteriophage Mu DNA inversion system gin, Fis (Factor for Inversion Stimulation) regulates many genetic systems. To determine the base frequency conservation required for Fis to locate its binding sites, we collected a set of 60 experimentally defined wild-type Fis DNA binding sequences. The sequence logo for Fis binding sites showed the significance and likely kinds of base contacts, and these are consistent with available experimental data. Scanning with an information theory based weight matrix within fis, nrd, tgt/sec and gin revealed Fis sites not previously identified, but for which there are published footprinting and biochemical data. DNA mobility shift experiments showed that a site predicted to be 11 bases from the proximal Salmonella typhimurium hin site and a site predicted to be 7 bases from the proximal P1 cin site are bound by Fis in vitro. Two predicted sites separated by 11 bp found within the nrd promoter region, and one in the tgt/sec promoter, were also confirmed by gel shift analysis. A sequence in aldB previously reported to be a Fis site, for which information theory predicts no site, did not shift. These results demonstrate that information analysis is useful for predicting Fis DNA binding.
Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Proteínas de Escherichia coli , Proteínas de Ligação a RNA/metabolismo , RNA/metabolismo , Sequência de Bases , Sítios de Ligação , Proteínas de Transporte/genética , DNA/química , Proteínas de Ligação a DNA/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Fator Proteico para Inversão de Estimulação , Fatores Hospedeiros de Integração , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Regiões Promotoras Genéticas , Ligação Proteica , RNA/química , Proteínas de Ligação a RNA/genéticaRESUMO
Arabidopsis and other Brassicaceae produce an enormous diversity of aliphatic glucosinolates, a group of methionine (Met)-derived plant secondary compounds containing a beta-thio-glucose moiety, a sulfonated oxime, and a variable side chain. We fine-scale mapped GSL-ELONG, a locus controlling variation in the side-chain length of aliphatic glucosinolates. Within this locus, a polymorphic gene was identified that determines whether Met is extended predominantly by either one or by two methylene groups to produce aliphatic glucosinolates with either three- or four-carbon side chains. Two allelic mutants deficient in four-carbon side-chain glucosinolates were shown to contain independent missense mutations within this gene. In cell-free enzyme assays, a heterologously expressed cDNA from this locus was capable of condensing 2-oxo-4-methylthiobutanoic acid with acetyl-coenzyme A, the initial reaction in Met chain elongation. The gene methylthioalkylmalate synthase1 (MAM1) is a member of a gene family sharing approximately 60% amino acid sequence similarity with 2-isopropylmalate synthase, an enzyme of leucine biosynthesis that condenses 2-oxo-3-methylbutanoate with acetyl-coenzyme A.
Assuntos
Arabidopsis/genética , Glucosinolatos/metabolismo , Metionina/metabolismo , Elongação Traducional da Cadeia Peptídica , 2-Isopropilmalato Sintase/metabolismo , Acetilcoenzima A/metabolismo , Arabidopsis/metabolismo , Mapeamento Cromossômico , Éxons , Regulação da Expressão Gênica de Plantas , Glucosinolatos/genética , Íntrons , Dados de Sequência Molecular , Família Multigênica , Oxo-Ácido-Liases/genéticaRESUMO
Mouse effector cells mediating natural cytotoxicity against tumor cells have been previously thought to be lymphocytes that lack any detectable cell surface markers. The present study presents evidence for receptors for the Fc portion of IgG on these cells. By adsorption of cytotoxic spleen cells on monolayers of sheep erythrocytes (E) plus IgG antibodies to sheep erythrocytes (EA), 50 to 96% of the total cytotoxic reactivity could be removed. Parallel adsorption of cells on E monolayers or on EA monolayers coated with protein A, to block the Fc portion of IgG, resulted in little or no depletion of cytotoxic activity. The presence of Fc receptors on the NK cells was confirmed by combining EA rosette formation with velocity sedimentation at unit gravity. Peak cytotoxicity occurred at the same sedimentation velocity as the peak of Fc-positive cells. After EA rosette formation, there was a shift to a higher sedimentation velocity in the Fc-positive cells and in the natural cytotoxic activity. The increase in sedimentation velocity of NK activity that was observed in these experiments indicated that most of the cells had only bound a small number (three or four) of antibody-coated erythrocytes. Together, these data indicate that cells with Fc receptors account for most of the total lytic activity of normal mouse spleen cells.
Assuntos
Imunidade Celular , Fragmentos Fc das Imunoglobulinas , Coriomeningite Linfocítica/imunologia , Animais , Anticorpos , Separação Celular , Testes Imunológicos de Citotoxicidade , Eritrócitos/imunologia , Técnicas Imunológicas , Técnicas de Imunoadsorção , Masculino , Camundongos , Camundongos Endogâmicos CBA , Camundongos NusRESUMO
BACKGROUND: Excess tissue matrix accumulates in systemic sclerosis (SSc), accounting for both visceral and dermal fibrosis. It is suggested that decreased serum levels of matrix metalloproteinases (MMPs) or increased levels of tissue inhibitors of matrix metalloproteinases (TIMPs) may account for this matrix accumulation. OBJECTIVE: To measure serum levels of tissue inhibitors of metalloproteinases, TIMP-1, TIMP-2, and collagenase-1 (MMP-1), in patients with diffuse cutaneous systemic sclerosis (dcSSc), limited cutaneous systemic sclerosis (lcSSc), primary Raynaud's phenomenon (RP), and in normal controls. METHODS: Serum samples from patients with dcSSc (n=83), lcSSc (n=87), RP (n=80), and normal controls (n=98) were analysed using enzyme linked immunosorbent assays (ELISAs) for total TIMP-1, TIMP-2, and MMP-1. Results from each assay were analysed by the Kruskal-Wallis test. Dunn's multiple comparison post-test was then applied between groups. RESULTS: TIMP-1 levels were significantly raised in dcSSc and lcSSc groups compared with the RP group and normal controls (p<0.01 to p<0.001). In the dcSSc group, TIMP-1 levels were significantly higher in early disease (<2 years) than in late stage disease (>4 years) (p<0.05). This was not found for the lcSSc group. Serum TIMP-2 and MMP-1 levels in dcSSc and lcSSc did not differ significantly from those in normal controls. Increased levels of TIMPs were not convincingly associated with organ disease. No assay result correlated with autoantibody status (anti-topoisomerase 1 (anti-Scl-70), anticentromere antibody, or anti-RNA polymerase). No significant differences in serum TIMP-1, TIMP-2, or MMP-1 levels were shown in the RP group compared with normal controls. CONCLUSIONS: Raised TIMP-1 levels in the SSc groups support the hypothesis that matrix accumulation occurs in SSc at least in part owing to decreased degradation. Moreover, the variation in TIMP-1 levels between the early and late disease stages of dcSSc seems to reflect the early progressive course of dermal fibrosis seen clinically. The expected reduction in serum MMP-1 levels in the SSc groups was not found. This suggests that tissue matrix accumulation is due to increased inhibitors rather than to decreased MMPs.