Composition of dissolved organic matter within a lacustrine environment

Freshwater dissolved organic matter (DOM) is a complex mixture of chemical components that are central to many environmental processes, including carbon and nitrogen cycling. However, questions remain as to its chemical characteristics, sources and transformation mechanisms. Here, we employ 1- and 2-D nuclear magnetic resonance (NMR) spectroscopy to investigate the structural components of lacustrine DOM from Ireland, and how it varies within a lake system, as well as to assess potential sources. Major components found, such as carboxyl-rich alicyclic molecules (CRAM) are consistent with those recently identified in marine and freshwater DOM. Lignin-type markers and protein/peptides were identified and vary spatially. Phenylalanine was detected in lake areas influenced by agriculture, whereas it is not detectable where zebra mussels are prominent. The presence of peptidoglycan, lipoproteins, large polymeric carbo- hydrates and proteinaceous material supports the substantial contribution of material derived from microorganisms. Evidence is provided that peptidoglycan and silicate species may in part originate from soil microbes

A 49-year-old man with neuropsychiatric symptoms followed by progressive cognitive decline.

No abstract is available for this article

Estimation of the conduction velocity of sympathetic sudomotor c fibers in healthy subjects: study of sympathetic skin reflex

The aim of this study was to establish a simple method for estimating the conduction velocity (CV) of postganglionic sympathetic sudomotor C fibres (SSFCV) in the upper and lower limbs by simultaneously measuring, the sympathetic skin reflex (SSR) in two distant sites. Fifty healthy volunteers were studied. SSRs were recorded with standard surface electrodes applied to both proximal (axilla and crural line) and distal sites for each limb (hand and foot). The CV of the efferent branch of the SSR was calculated by dividing the difference in the latencies of the response from two recording sites by the distance between the sites (axilla-hand for upper limb; crural line-foot for lower limb). Day-to-day reproducibility and intra-individual variability of the SSFCV were calculated. For the upper limbs, the SSFCV in the axilla-hand tract was 2.0 +/-0.3 m/sec (range 1.6-2.4 m/sec). For the lower limb, the SSFCV in the crural line-foot tract was 1.4 +/-0.4 m/sec (range 1.2-1.6 m/sec). Mean intra-individual variability of the SSFCV for the upper and lower limbs was 0.11 and 0.09, respectively. The coefficient of variation of the SSFCV for the upper and lower limbs was 5.1% and 5.4%, respectively. Our data show that this simple and non-invasive method can reliably be used to measure the CV of the sympathetic sudomotor fibres, in suitable temperature conditions, and may be useful when investigating the physiological functions of peripheral nerves in patients with peripheral neuropathies

Mutant PrPCJD prevails over wild-type PrPCJD in the brain of V210I and R208H genetic Creutzfeldt-Jakob disease patients.

Creutzfeldt–Jakob disease (CJD) is a neurodegenerative disorder characterized by the deposition of the pathological conformer (PrPCJD) of the host encoded cellular prion protein (PrPC). In genetic CJD associated with V210I or R208H PrP substitutions, the pathogenic role of mutant residues is still poorly understood. To understand how V210I or R208H PrP mutations facilitate the development of the disease, we determined by mass spectrometry the quantitative ratio of mutant/wild-type PrPCJD allotypes in brains from affected subjects. We found that the mutant PrPCJD allotypes moderately exceeds of 2- or 3-fold the amount of the wild-type counterpart suggesting that these mutations mainly exert their pathogenic effect on the onset of the pathogenic cascade. Different mechanisms can be hypothesized to explain the pathogenic role of mutant residues: V210I and R208H substitutions can increase the concentration of PrPC and the probability to form insoluble aggregates, or they may facilitate the formation of pathological intermediates, or, alternatively, they may increase the affinity for ligands that are involved in the initial phases of PrPCJD formation and aggregation. Whatever the mechanism, the enrichment found for the mutated PrPCJD species indicates that these altered structures are more prone, with respect to the non-mutated ones, to be captured in the polymer- ization process either at the onset or during the development of the disease

Creutzfeldt Jakob Disease Associated with the R208H-129V Haplotype in the Protein Gene

Human Transmissible Spongiform Encephalopaties (TSEs) or prion diseases occur in sporadic, acquired and genetic forms. All the genetic forms of human TSEs are linked to point or insertion mutations of the PRNP and several of these genetic forms are transmissible. Among the rarer point mutations, R208H was reported in 3 patient (JA. Mastrianni; et al. 1996; S. Capellari et al. 2005; C. Basset-Leobon et al. 2006). Here we described the clinical and pathological features of the CJD phenotype associated with the R208H-129VV haplotype in an Italian patient. Case report A 64-year-old woman was referred to the Italian National Register of the Creutzfeldt-Jakob disease and related disorders, with a clinical presentation characterized by mood disorder and ataxia. Two months after the onset, she showed cognitive decay, cerebellar symptoms, pyramidal symptoms involving the left leg, and a progressive action myoclonus of left hand. Four months later the patient was bed ridden in a state of akinetic mutism. The family history was negative for dementia or neurological disorders. The protein 14-3-3 test gave a positive result. The EEG became typical 4 months after the onset. The MRI of the brain showed mild hyperintense signals in the basal ganglia on T2-weighted images. The sequence of the PRNP gene ORF revealed a mutation at the codon 208 with the substitution of histidine for arginine (R208H) and the polymorphism Val/Val at the level of the codon 129. Death occurred 28 months after onset. Neuropathological examination showed severe spongiform changes in the cerebral cortex, striatum, thalamus and cerebellum. Conclusions: this report is the first on the R208H mutation found in association with val/val polymorphism in Italy and it strengthens the linkage of the R208H mutation to CJD

MRI lesion profiles in sporadic Creutzfeldt-Jakob disease

BACKGROUND: With respect to sporadic Creutzfeldt-Jakob disease (sCJD), six molecular subtypes (MM1, MM2, MV1, MV2, VV1, and VV2) have been described, which vary with respect to age at disease onset, disease duration, early symptoms, and neuropathology. MRI signal alterations were reported to correlate with distinct Creutzfeldt-Jakob disease (CJD) subtypes. This multicenter, international study aimed to describe the brain MRI findings associated with each of the sCJD molecular subtypes. METHODS: Pathologically confirmed sCJD cases with codon 129 genotype (MM, MV, and VV), PrP(Sc) type, and fluid-attenuated inversion recovery (FLAIR) or diffusion-weighted imaging (DWI) were collected in seven countries. All MRI scans were assessed for signal changes according to a standard protocol encompassing seven cortical regions, basal ganglia, thalamus, and cerebellum. RESULTS: MRI scans were evaluated in 211 CJD patients (98 MM1, 23 MM2, 19 MV1, 30 MV2, 9 VV1, and 32 VV2). Basal ganglia hyperintensities occurred most frequently in MV2, VV2, and MM1 subtypes (79, 77, and 70%). Wide cerebral cortical signal increase was most common in VV1, MM2, and MV1 subtypes (86, 77, and 77%). Thalamic hyperintensities occurred most often in VV2 (45%) and MV2 (43%). The most consistent finding across most subtypes was high signal in basal ganglia, with these abnormalities found in 63% (FLAIR) and 71% (DWI). CONCLUSION: Cortical signal increase and hyperintensities in the basal ganglia and thalamus are detected by MRI across all molecular sporadic Creutzfeldt-Jakob disease subtypes. Our findings argue that characteristic MRI lesion patterns may occur for each molecular subtype

Aproveitamento de nutrientes e de energia da ração de codornas japonesas em postura com o uso de fitase Nutrient and energy utilization from the feedings of laying Japanese quails by using phytase

O experimento foi realizado para avaliar o efeito da adição de fitase no aproveitamento dos ingredientes da ração para codornas. Foram utilizadas 200 codornas japonesas fêmeas com 251 dias de idade, peso médio de 187,2 ± 6,0 g e taxa de produção de ovos de 84,8%, distribuídas em delineamento inteiramente casualizado com quatro dietas experimentais e cinco repetições de dez aves por unidade experimental. As dietas experimentais consistiram de uma ração basal à base de milho e farelo de soja, formulada para atender às exigências nutricionais das codornas e às recomendações da matriz da fitase, suplementada com 0, 200, 400 ou 600 unidades de fitase (uf/kg). Utilizando-se o método de coleta total de excretas, foram determinados os valores de matéria seca ingerida, matéria seca excretada, energia metabolizável aparente (EMA), energia metabolizável aparente corrigida pela retenção de nitrogênio (EMAn) e os coeficientes de metabolizabilidade da energia corrigida ou não pelo balanço de nitrogênio. Foi calculada também a quantidade de fósforo, cálcio e nitrogênio retido por ave/dia. De maneira geral, houve melhora no aproveitamento da energia das rações com a suplementação de fitase. Os níveis de 195 e 186 uf/kg resultaram em maior aproveitamento da EMA e EMAn. Não houve diferença na retenção de fósforo e cálcio. O nível de 600 (uf/kg) promove menor excreção de nitrogênio, porém o de 368 uF/kg é suficiente para máxima retenção de nitrogênio pelas codornas.<br>This experiment was conducted to evaluate the effect of phytase addition on the use of feeding ingredients for laying quails. It was used 200 female Japanese quails at 251 days of age at an average weight of 187.2 ± 6.0 g and egg production rate of 84.8%. The quails were distributed in a complete random design with four experimental diets and five repetitions of ten birds per experimental unity. The experimental diets were consisted of corn and soybean meal based feedings formulated in order to meet the nutritional requirements of the quails and to the recomendations of phytase matrix supplemented with 0, 200, 400 or 600 phytase units (PU/kg). By using the method of total excreta collection, it was determined the values of ingested dry matter, excreted dry matter, apparent metabolizable energy (AME), apparent metabolizable energy corrected by nitrogen retention (AMEn), and the coefficients of energy metabolizability corrected or not by nitrogen balance. It was also calculated the quantities of phosphorus, calcium, and nitrogen retained by bird/day. In general, there was an improvement on the use of energy from feeding with phytase supplementation. Levels of 195 and 186 PU/kg resulted in a better use of AME and AMEn. There was no difference on retention of phosphorus and calcium. Level of 600 (PU/kg) promotes the lowest nitrogen excretion, however, 368 PU/kg is enough for a maximal retention of nitrogen by the quails