41 resultados para 640


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The occurrence of glucosuria in the absence of hyperglycemia is distinctive for renal glucosuria. SGLT2 mutations provoke familial renal glucosuria characterized by persistent glucosuria in the absence of any other renal tubular dysfunction. Renal glucosuria associated with others proximal tubular dysfunctions points to Fanconi syndrome. This generalized dysfunction of proximal tubule needs to be treated and may progress regarding its aetiology to chronic renal failure. The development and study of models of Fanconi syndrome has recently contributed to a better knowledge of the mechanisms implicated in the tubular transport of glucose and low-molecular-weight-proteins. This article reviews these recent developments.

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BACKGROUND: Acute exposure to high altitude stimulates free radical formation in lowlanders, yet whether this persists during chronic exposure in healthy, well-adapted and maladapted highlanders suffering from chronic mountain sickness (CMS) remains to be established. METHODS: Oxidative-nitrosative stress (as determined by the presence of the biomarkers ascorbate radical [A •- ], via electron paramagnetic resonance spectroscopy, and nitrite [NO 2 2 ], via ozone-based chemiluminescence) was assessed in venous blood of 25 male highlanders in Bolivia living at 3,600 m with CMS (n 5 13, CMS 1 ) and without CMS (n 5 12, CMS 2 ). Twelve age- and activity-matched, healthy, male lowlanders were examined at sea level and during acute hypoxia. We also measured fl ow-mediated dilatation (FMD), arterial stiffness defined by augmentation index normalized for a heart rate of 75 beats/min (AIx-75), and carotid intima-media thickness (IMT). RESULTS: Compared with normoxic lowlanders, oxidative-nitrosative stress was moderately increased in the CMS 2 group ( P , .05), as indicated by elevated A •- (3,191 457 arbitrary units [AU] vs 2,640 445 AU) and lower NO 2 2 (206 55 nM vs 420 128 nM), whereas vascular function remained preserved. This was comparable to that observed during acute hypoxia in lowlanders in whom vascular dysfunction is typically observed. In contrast, this response was markedly exaggerated in CMS 1 group (A •- , 3,765 429 AU; NO 2 2 , 148 50 nM) compared with both the CMS 2 group and lowlanders ( P , .05). This was associated with systemic vascular dysfunction as indicated by lower ( P , .05 vs CMS 2 ) FMD (4.2% 0.7% vs 7.6% 1.7%) and increased AIx-75 (23% 8% vs 12% 7%) and carotid IMT (714 127 m M vs 588 94 m M). CONCLUSIONS: Healthy highlanders display a moderate, sustained elevation in oxidative-nitrosative stress that, unlike the equivalent increase evoked by acute hypoxia in healthy lowlanders, failed to affect vascular function. Its more marked elevation in patients with CMS may contribute to systemic vascular dysfunction.

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We have recently shown that immunophotodetection of human colon carcinomas in nude mice and in patients is possible by using anti-carcinoembryonic antigen monoclonal antibodies (MAb) coupled to fluorescein. The most common clinical application of photodiagnosis has been for the detection of squamous cell carcinomas (SCC) in the upper respiratory tract, but the free dyes used have a poor tumor selectivity. We selected the known MAb E48 directed against SCC and coupled it to a fluorescent dye: indopentamethinecyanin (indocyanin). This dye has an advantage over fluorescein in that it emits a more penetrating fluorescent red signal at 667 nm after excitation with a laser ray of 640 nm. In vitro, an conjugate with an indocyanin:MAb molar ratio of 2, and an additional trace labeling with 125I, showed more than 80% of binding to cells from the SCC line A431. In vivo, when injected i.v. into nude mice bearing xenografts of the same carcinoma line, the MAb E48-(indocyanin)2 conjugate was almost as efficient as the unconjugated MAb E48 in terms of specific tumor localization: 15% of the injected dose per g of tumor at 24 h after injection and a tumor:overall normal tissue ratio of 6-8. There was no selective tumor localization of an irrelevant IgG1-(indocyanin)2 conjugate. Immunophotodetection of the s.c. SCC xenografts on mice given injections of 100 micrograms of MAb E48-(indocyanin), conjugate (representing 1 microgram of indocyanin) was performed at 24 h. Upon laser irradiation, clearly detectable red fluorescence from the indocyanin-MAb conjugate was observed specifically in the SCC xenografts across the mouse skin. In comparison, injection of 100 micrograms of a MAb E48 coupled to 2 micrograms of fluorescein gave a specific green fluorescence signal in the tumor xenografts, which was detectable, however, only after removing the mouse skin. Injection i.v. of a 15 times higher amount of free indocyanin (15 micrograms) gave a diffuse red fluorescence signal all over the mouse body with no definite increase in intensity in the tumor, indicating a lack of tumor selectivity of the free dye. The results demonstrate the possibility of broadening and improving the efficiency of tumor immunophotodiagnosis by coupling to a MAb directed against SCC, a fluorescent dye absorbing and emitting at higher wavelength than fluorescein, and thus having deeper tissue penetration and lower tissue autofluorescence. Such a demonstration opens the way to a new form of clinical immunophotodiagnosis and possibly to the development of a more specific approach to phototherapy of early bronchial carcinomas.

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Vertical electric soundings, 2D resistivity imaging and several logging measurements were performed at Kappelen test site to identify the various geolelectric facies that allowed determining the tabular and horizontal structure of the aquifer. The surface-based geoelectric methods allowed for a reliable characterization of the overall structure and the geometry of the aquifer, while geophysical logging methods allowed for inferring detailed hydrogeophysical characteristics, such as the electrical resistivity, total porosity, global and matrix density and hydraulic conductivity. The synoptic interpretation and integration of this broad and diverse database allows for constraining the key hydrological characteristics and hence forms the basis for the detailed hydraulic modelling of flow and transport process.

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This retrospective, multicentre study evaluated patients with lymphangioleiomyomatosis (LAM) and pre-capillary pulmonary hypertension (PH) by right heart catheterisation. It was conducted in 20 females with a mean ± SD age of 49 ± 12 yrs and a mean ± SD time interval between LAM and PH diagnoses of 9.2 ± 9.8 yrs. All, except for one patient, were receiving supplemental oxygen. 6-min walking distance was mean ± SD 340 ± 84 m. Haemodynamic characteristics were: mean pulmonary artery pressure (PAP) 32 ± 6 mmHg, cardiac index 3.5 ± 1.1 L · min(-1) · m(-2) and pulmonary vascular resistance (PVR) 376 ± 184 dyn · s · cm(-5). Mean PAP was >35 mmHg in only 20% of cases. The forced expiratory volume in 1 s was 42 ± 25%, carbon monoxide transfer factor was 29 ± 13%, and arterial oxygen tension (P(a,O(2))) was 7.4 ± 1.3 kPa in room air. Mean PAP and PVR did not correlate with P(a,O(2)). In six patients who received oral pulmonary arterial hypertension (PAH) therapy, the PAP decreased from 33 ± 9 mmHg to 24 ± 10 mmHg and the PVR decreased from 481 ± 188 dyn · s · cm(-5) to 280 ± 79 dyn · s · cm(-5). The overall probability of survival was 94% at 2 yrs. Pre-capillary PH of mild haemodynamic severity may occur in patients with LAM, even with mild pulmonary function impairment. PAH therapy might improve the haemodynamics in PH associated with LAM.

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AIMS: The aim of the study was to explore whether the concept of heavy substance use over time can be used as definition of substance use disorder. METHODS: Narrative review. RESULTS: Heavy use over time clearly underlies the neurobiological changes associated with current thinking of substance use disorders. In addition, there is evidence that heavy use over time can explain the majority of social problems and of burden of disease (morbidity and mortality). A definition of substance use disorders via heavy use over time would avoid some of the problems of current conceptualizations, for instance the cultural specificity of concepts such as loss of control. Finally, stressing the continuum of use may avoid the high level of stigmatization currently associated with substance use disorders. CONCLUSION: 'Heavy substance use over time' seems to be a definition of substance use disorders in line with results of basic research and epidemiology. Additionally, it reduces stigmatization. This approach should thus be further explored.

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PURPOSE OF REVIEW: We present an overview of recent concepts in mechanisms underlying cognitive decline associated with brain aging and neurodegeneration from the perspective of MRI. RECENT FINDINGS: Recent findings challenge the established link between neuroimaging biomarkers of neurodegeneration and age-related or disease-related cognitive decline. Amyloid burden, white matter hyperintensities and local patterns of brain atrophy seem to have differential impact on cognition, particularly on episodic and working memory - the most vulnerable domains in 'normal aging' and Alzheimer's disease. Studies suggesting that imaging biomarkers of neurodegeneration are independent of amyloid-β give rise to new hypothesis regarding the pathological cascade in Alzheimer's disease. Findings in patients with autosomal-dominant Alzheimer's disease confirm the notion of differential temporal trajectory of amyloid deposition and brain atrophy to add another layer of complexity on the basic mechanisms of cognitive aging and neurodegeneration. Finally, the concept of cognitive reserve in 'supernormal aging' is questioned by evidence for the preservation of neurochemical, structural and functional brain integrity in old age rather than recruitment of 'reserves' for maintaining cognitive abilities. SUMMARY: Recent advances in clinical neuroscience, brain imaging and genetics challenge pathophysiological hypothesis of neurodegeneration and cognitive aging dominating the field in the last decade and call for reconsidering the choice of therapeutic window for early intervention.

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Mismatch negativity (MMN) overlaps with other auditory event-related potential (ERP) components. We examined the ERPs of 50 9- to 11-year-old children for vowels /i/, /y/ and equivalent complex tones. The goal was to separate MMN from obligatory ERP components using principal component analysis and equal probability control condition. In addition to the contrast of the deviant minus standard response, we employed the contrast of the deviant minus control response, to see whether the obligatory processing contributes to MMN in children. When looking for differences in speech deviant minus standard contrast, MMN starts around 112 ms. However, when both contrasts are examined, MMN emerges for speech at 160 ms whereas for nonspeech MMN is observed at 112 ms regardless of contrast. We argue that this discriminative response to speech stimuli at 112 ms is obligatory in nature rather than reflecting change detection processing.

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Combination chemotherapy is widely accepted for patients with advanced gastric cancer, but uncertainty remains regarding the choice of the regimen. Objectives: To assess the effect of: Comparison 1) irinotecan versus non-irinotecancontaining regimens, comparison 2) docetaxel versus non-docetaxel-containing regimens, comparison 3) regimens including oral 5-FU prodrugs versus intravenous fluoropyrimidines, comparison 4) oxaliplatin versus cisplatin-containing regimens on overall survival. Search Strategy: We searched: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, proceedings from ECCO, ESMO, ASCO until December 2009. Selection Criteria: Randomised controlled trials on the above mentioned chemotherapy regimens in advanced or metastatic denocarcinoma of the stomach or GE-junction. Results: The meta-analysis of overall survival for comparison 1) included 4 trials, 640 patients, and results in a HR of 0.86 (95% CI 0.73-1.02) in favour of the irinotecancontaining regimens. For comparison 2) 4 trials with a total of 924 patients have been included in the analysis of overall survival. The resulting HR is 0.93 (95% CI 0.79-1.09) in favour of the docetaxel-containing regimens, with moderate heterogeneity (I2 =7%). For comparison 3 and 4, one major relevant study (Cunningham 2008) could not be included in this meta-analysis after discussion because it included patients with squamous cell cancer of the esophagus as well. Thus, for comparison 3) one relevant study (Kang 2009; 316 patients) comparing capecitabine versus 5-FU in combination with cisplatin is eligible. The resulting HR is 0.85 (95%CI 0.65-1.11) in favour of the oral regimen. For comparison 4) two eligible trials were identified (Al Batran 2008, Popov 2008; 292 patients) with a resulting HR of 0.82 (95% CI 0.47-1.45) in favour of the oxaliplatin-based regimens. For three further trials data is incomplete at present. Conclusions: Chemotherapy combinations including irinotecan, oxaliplatin, docetaxel or oral 5-FU prodrugs are alternative treatment options to cisplatin/5-FU or cisplatin/ 5-FU/anthracycline-combinations, but do not provide significant advantages in overall survival. Supported by: KKS Halle, grant number [BMBF/FKZ 01GH01GH0105]. Disclosure: All authors have declared no conflicts of interest.

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Trisomy 21 is the most frequent genetic cause of cognitive impairment. To assess the perturbations of gene expression in trisomy 21, and to eliminate the noise of genomic variability, we studied the transcriptome of fetal fibroblasts from a pair of monozygotic twins discordant for trisomy 21. Here we show that the differential expression between the twins is organized in domains along all chromosomes that are either upregulated or downregulated. These gene expression dysregulation domains (GEDDs) can be defined by the expression level of their gene content, and are well conserved in induced pluripotent stem cells derived from the twins' fibroblasts. Comparison of the transcriptome of the Ts65Dn mouse model of Down's syndrome and normal littermate mouse fibroblasts also showed GEDDs along the mouse chromosomes that were syntenic in human. The GEDDs correlate with the lamina-associated (LADs) and replication domains of mammalian cells. The overall position of LADs was not altered in trisomic cells; however, the H3K4me3 profile of the trisomic fibroblasts was modified and accurately followed the GEDD pattern. These results indicate that the nuclear compartments of trisomic cells undergo modifications of the chromatin environment influencing the overall transcriptome, and that GEDDs may therefore contribute to some trisomy 21 phenotypes.

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Only a very small fraction of long noncoding RNAs (lncRNAs) are well characterized. The evolutionary history of lncRNAs can provide insights into their functionality, but the absence of lncRNA annotations in non-model organisms has precluded comparative analyses. Here we present a large-scale evolutionary study of lncRNA repertoires and expression patterns, in 11 tetrapod species. We identify approximately 11,000 primate-specific lncRNAs and 2,500 highly conserved lncRNAs, including approximately 400 genes that are likely to have originated more than 300 million years ago. We find that lncRNAs, in particular ancient ones, are in general actively regulated and may function predominantly in embryonic development. Most lncRNAs evolve rapidly in terms of sequence and expression levels, but tissue specificities are often conserved. We compared expression patterns of homologous lncRNA and protein-coding families across tetrapods to reconstruct an evolutionarily conserved co-expression network. This network suggests potential functions for lncRNAs in fundamental processes such as spermatogenesis and synaptic transmission, but also in more specific mechanisms such as placenta development through microRNA production.