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1.
Diabetes Obes Metab ; 16(1): 63-74, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23859428

RESUMO

AIMS: The PROactive study investigated pioglitazone for secondary prevention of macrovascular events in type 2 diabetes mellitus. Pioglitazone showed a 10% (non-significant) relative risk (RR) reduction for the primary composite endpoint and a significant 16% reduction for the main secondary endpoint (death, myocardial infarction, stroke) after a mean 34.5 months. There was no difference in cumulative malignancy incidence, but an imbalance in bladder malignancies (pioglitazone 14, placebo 5). We present a pre-specified 6-year interim analysis of a 10-year observational follow-up. METHODS: Any patient completing PROactive was eligible. No study treatments were provided. A Cox proportional hazard model compared non-adjudicated macrovascular events (same endpoints as PROactive excluding acute coronary syndrome) based on original randomization. Malignancies were compared using conventional RR ratios. RESULTS: Of 5238 randomized patients, 3599 (74%) entered the follow-up. For the follow-up (mean 5.8 years) or combined double-blind and follow-up periods (≤9.5 years, mean 8.7), there were no statistically significant differences in primary or main secondary endpoints. For the combined period, a similar percentage of patients had any diagnosed malignancy (RR = 1.05, 95% CI [0.89, 1.24]) or bladder malignancy (RR = 1.06, 95% CI [0.59, 1.89]) in the pioglitazone and placebo groups. There were fewer cases of bladder malignancy with pioglitazone (15 [0.6%] vs. 19 [0.7%] for placebo) for the combined period when events diagnosed in the first 365 days were excluded, and fewer cases for the follow-up period alone (10 [0.5%] vs. 17 [1.0%] for placebo). Further analyses of pioglitazone use (including use during follow-up) found no significant difference in bladder malignancies between any and no pioglitazone use for the combined period. CONCLUSIONS: These data suggest that improved macrovascular outcomes seen with pioglitazone subside without continued pioglitazone treatment. The double-blind period bladder cancer imbalance did not persist in follow-up.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Angiopatias Diabéticas/prevenção & controle , Hipoglicemiantes/administração & dosagem , Tiazolidinedionas/administração & dosagem , Neoplasias da Bexiga Urinária/induzido quimicamente , Idoso , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Hipoglicemiantes/efeitos adversos , Incidência , Masculino , Pessoa de Meia-Idade , Pioglitazona , Modelos de Riscos Proporcionais , Tiazolidinedionas/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Neoplasias da Bexiga Urinária/epidemiologia
2.
Phys Rev Lett ; 103(19): 191301, 2009 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-20365914

RESUMO

Particle cascades initiated by ultrahigh energy neutrinos in the lunar regolith will emit an electromagnetic pulse with a time duration of the order of nanoseconds through a process known as the Askaryan effect. It has been shown that in an observing window around 150 MHz there is a maximum chance for detecting this radiation with radio telescopes commonly used in astronomy. In 50 h of observation time with the Westerbork Synthesis Radio Telescope array we have set a new limit on the flux of neutrinos, summed over all flavors, with energies in excess of 4x10(22) eV.

4.
Nature ; 435(7040): 313-6, 2005 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-15902250

RESUMO

The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.

5.
Phys Rev Lett ; 89(15): 151301, 2002 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-12365978

RESUMO

We derive constraints on cosmological parameters and the properties of the lensing galaxies from gravitational lens statistics based on the final Cosmic Lens All Sky Survey data. For a flat universe with a classical cosmological constant, we find that the present matter fraction of the critical density is Omega(m)=0.31(+0.27)(-0.14) (68%)+0.12-0.10 (syst). For a flat universe with a constant equation of state for dark energy w=p(x)(pressure)/rho(x)(energy density), we find w<-0.55(+0.18)(-0.11) (68%).

6.
Nature ; 415(6867): 57-60, 2002 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-11780113

RESUMO

The liberation of gravitational energy as matter falls onto a supermassive black hole at the centre of a galaxy is believed to explain the high luminosity of quasars. The variability of this emission from quasars and other types of active galactic nuclei can provide information on the size of the emitting regions and the physical process of fuelling the black hole. Some active galactic nuclei are variable at optical (and shorter) wavelengths, and display radio outbursts over years and decades. These active galactic nuclei often also show faster intraday variability at radio wavelengths. The origin of this rapid variability has been extensively debated, but a correlation between optical and radio variations in some sources suggests that both are intrinsic. This would, however, require radiation brightness temperatures that seem physically implausible, leading to the suggestion that the rapid variations are caused by scattering of the emission by the interstellar medium inside our Galaxy. Here we show that the rapid variations in the extreme case of quasar J1819+3845 (ref. 10) indeed arise from interstellar scintillation. The transverse velocity of the scattering material reveals the presence of plasma with a surprisingly high velocity close to the Solar System.

7.
Breast ; 10(1): 6-11, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14965550

RESUMO

The period 1990-1997 saw the implementation of a nationwide breast cancer screening programme in the Netherlands, which provided biennial mammography for all women aged 50-69 years (50-75 years at present). The National Evaluation Team monitors the programme annually collecting regional data on screening outcomes; regional cancer registries provide data on interval cancers and on breast cancers in unscreened women by linkage of cancer registry data to data on screened women. Of 4 million women invited, 78.5% attended for screening. Screening resulted in 13.1 referrals, 9.2 biopsies and 6.1 breast cancers detected per 1000 women screened initially (6.9, 4.5 and 3.5 per 1000 in subsequently screened women, respectively). Within the first 2 years following screening 0.95 interval cancers per 1000 women-years were diagnosed. The stage distribution of screen-detected cancers was more favourable than that of interval cancers and of those diagnosed in unscreened women. The results are largely consistent with expectations. Results may nonetheless be further improved, particularly the detection rate in subsequent screens.

8.
J Biol Chem ; 275(47): 36899-909, 2000 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-10934215

RESUMO

Caffeoyl-coenzyme A O-methyltransferase (CCoAOMT) methylates, in vitro, caffeoyl-CoA and 5-hydroxyferuloyl-CoA, two possible precursors in monolignol biosynthesis in vivo. To clarify the in vivo role of CCoAOMT in lignin biosynthesis, transgenic poplars with 10% residual CCoAOMT protein levels in the stem xylem were generated. Upon analysis of the xylem, the affected transgenic lines had a 12% reduced Klason lignin content, an 11% increased syringyl/guaiacyl ratio in the noncondensed lignin fraction, and an increase in lignin-attached p-hydroxybenzoate but otherwise a lignin composition similar to that of wild type. Stem xylem of the CCoAOMT-down-regulated lines had a pink-red coloration, which coincided with an enhanced fluorescence of mature vessel cell walls. The reduced production of CCoAOMT caused an accumulation of O(3)-beta-d-glucopyranosyl-caffeic acid, O(4)-beta-d-glucopyranosyl-vanillic acid, and O(4)-beta-d-glucopyranosyl-sinapic acid (GSA), as authenticated by (1)H NMR. Feeding experiments showed that O(3)-beta-d-glucopyranosyl-caffeic acid and GSA are storage or detoxification products of caffeic and sinapic acid, respectively. The observation that down-regulation of CCoAOMT decreases lignin amount whereas GSA accumulates to 10% of soluble phenolics indicates that endogenously produced sinapic acid is not a major precursor in syringyl lignin biosynthesis. Our in vivo results support the recently obtained in vitro enzymatic data that suggest that the route from caffeic acid to sinapic acid is not used for lignin biosynthesis.


Assuntos
Regulação para Baixo , Glucosídeos/metabolismo , Lignina/metabolismo , Metiltransferases/metabolismo , Fenóis/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Acil Coenzima A/metabolismo , Ácidos Cafeicos/metabolismo , Configuração de Carboidratos , Cromatografia Líquida de Alta Pressão , Ácidos Cumáricos/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Modelos Químicos , Ácido Vanílico/análogos & derivados
9.
Br J Cancer ; 81(5): 912-7, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10555768

RESUMO

The nationwide breast cancer screening programme in The Netherlands for women aged 50-69 started in 1989. In our study we assessed the occurrence and stage distribution of interval cancers in women screened during 1990-1993. Records of 0.84 million screened women were linked to the regional cancer registries yielding a follow-up of at least 2.5 years. Age-adjusted incidence rates and relative (proportionate) incidences per tumour size including ductal carcinoma in-situ were calculated for screen-detected and interval cancers, and cancers in not (yet) screened women, comparing them with published data from the UK regions North West and East Anglia. In total 1527 interval cancers were identified: 0.95 and 0.99 per 1000 woman-years of follow-up in the 2-year interval after initial and subsequent screens respectively. In the first year after initial screening interval cancers amounted to 27% (26% after subsequent screens) of underlying incidence, and in the second year to 52% (55%). Generally, interval cancers had a more favourable tumour size distribution than breast cancer in not (yet) screened women. The Dutch programme detected relatively less (favourable) invasive cancers in initial screens than the UK programme, whereas the number of interval cancers confirms UK findings. Measures should be considered to improve the detection of small invasive cancers and to reduce false-negative rates, even if this will lead to increasing referral rates.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Carcinoma Ductal de Mama/epidemiologia , Idoso , Neoplasias da Mama/patologia , Neoplasias da Mama/prevenção & controle , Carcinoma in Situ/diagnóstico , Carcinoma in Situ/epidemiologia , Carcinoma in Situ/patologia , Carcinoma in Situ/prevenção & controle , Carcinoma Ductal de Mama/diagnóstico , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/prevenção & controle , Feminino , Humanos , Incidência , Programas de Rastreamento , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Países Baixos/epidemiologia , Sistema de Registros , Fatores de Tempo , Reino Unido/epidemiologia
10.
Bioorg Med Chem Lett ; 9(21): 3159-64, 1999 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-10560744

RESUMO

Short-chain 3-fluoro-(dihydro)ceramide analogues are synthesized from L-serine using diethylaminosulfur trifluoride (DAST) as fluorinating agent. The apoptogenic activity of these compounds was measured in three different cell lines and compared with their hydroxylated counterparts.


Assuntos
Apoptose/efeitos dos fármacos , Ceramidas/síntese química , Compostos de Flúor/síntese química , Ceramidas/farmacologia , Dietilaminas/química , Flúor/química , Compostos de Flúor/farmacologia , Humanos , Linfócitos/efeitos dos fármacos , Células Tumorais Cultivadas
11.
FEBS Lett ; 452(3): 365-70, 1999 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-10386623

RESUMO

The human N-acetylglucosaminyltransferase I gene was introduced in the genome of Trichoderma reesei strain VTT-D-80133. Expression was studied after induction from the cellobiohydrolase I promoter. Successful in vivo transfer of GlcNAc was demonstrated by analyzing the neutral N-glycans which were synthesized on cellobiohydrolase I. Final proof of the formation of GlcNAcMan5GlcNAc2 was obtained by NMR analysis.


Assuntos
N-Acetilglucosaminiltransferases/metabolismo , Polissacarídeos/biossíntese , Trichoderma/fisiologia , Sequência de Carboidratos , Celulase/genética , Celulose 1,4-beta-Celobiosidase , Clonagem Molecular , Humanos , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , N-Acetilglucosaminiltransferases/genética , Oligossacarídeos/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Regiões Promotoras Genéticas , Proteínas Recombinantes/metabolismo , Esporos Fúngicos , Trichoderma/metabolismo
12.
Int J Cancer ; 75(5): 694-8, 1998 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-9495236

RESUMO

Based on an extensive cost-effectiveness analysis, the Dutch nation-wide breast cancer screening programme started in 1990, providing a biennial screen examination to women aged 50 to 69 years. The programme is monitored by the National Evaluation Team, which annually collects tabulated regional evaluation data to determine performance indicators. This study presents (trends in) the outcomes of initial and subsequent screening rounds, 1990-1995, and compares them to the predictions of the cost-effectiveness-analysis. Up to 1996, 88% of the target population was covered by the programme and more than 2.4 x 10(6) women were invited. The overall attendance rate was 77.5% with little differences between screening rounds and age groups; the highest rate was found in non-urbanised areas (82.4%). Of 1,000 initially (and 2 years thereafter) screened women, 13.4 (6.6) were referred for further investigation, 9.7 (4.4) were biopsied and 6.4 (3.4) had breast cancer. The positive predictive values of screen test and biopsy were 47% (51%) and 66% (78%), respectively. DCIS was diagnosed in 0.9 (0.5) and invasive cancers < or = 10 mm in 1.5 (1.0) per 1,000 screens. Lymph node metastases were found in 28% (24%) of the invasive cancers. Except the increasing attendance, which was much higher than expected, the results were fairly constant over the years. Contrary to initial screens, the results of subsequent screens did not fulfil expectations with regard to breast cancer detection and tumour size distribution. We conclude that the nation-wide screening programme is being implemented successfully. Given the results, the programme should contribute to a substantial breast cancer mortality reduction in the future. The discrepancy between observed and expected results in subsequent screens has to be watched carefully.


Assuntos
Neoplasias da Mama/diagnóstico , Fatores Etários , Idoso , Biópsia , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Feminino , Humanos , Metástase Linfática , Programas de Rastreamento/economia , Pessoa de Meia-Idade , Países Baixos , População Urbana
13.
Anal Biochem ; 257(1): 80-8, 1998 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-9512776

RESUMO

The pyrrolophenanthridine alkaloid lycorine has frequently been used as a specific inhibitor to help elucidate the function of ascorbic acid (vitamin C) in a wide range of biological processes. It was recently reported that this function can be exercised by inhibiting the activity of L-galactono-1,4-lactone dehydrogenase, the terminal enzyme of ascorbic acid biosynthesis, although working with the purified enzyme, we have been unable to repeat this result. Here, we present a procedure for the purification and analysis of lycorine by high-performance liquid chromatography from two Crinum species and describe for the first time a method that allows the simultaneous analysis of ascorbic acid and lycorine in tissue extracts of Crinum asiaticum by micellar electrokinetic chromatography.


Assuntos
Alcaloides de Amaryllidaceae , Ácido Ascórbico/análise , Cromatografia Líquida de Alta Pressão/métodos , Eletroforese Capilar/métodos , Fenantridinas/isolamento & purificação , Cromatografia em Camada Fina , Eletroquímica , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Micelas , Fenantridinas/análise , Folhas de Planta/química , Raízes de Plantas/química
14.
J Med Chem ; 40(23): 3765-72, 1997 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-9371242

RESUMO

The present study explores the C-3' site of the 3-deoxy-3-xylofuranosyl ring of nucleoside analogues with an adenine or N6-cyclopentyladenine (CPA) base moiety and evaluates the effect on adenosine receptor affinity. Two series of sugar-modified adenosines, i.e., 3'-amido-3'-deoxyadenosines and 3'-amidated 3'-deoxyxylofuranosyladenines, were synthesized and tested for their affinity at A1 and A2a receptors in rat brain cortex and rat striatum, respectively. The modest affinity found in the "xylo series" prompted us to synthesize the corresponding N6-cyclopentyl derivatives, which proved to be well accommodated by the A1 receptors with potencies in the lower nanomolar range. This represents a new perspective in the purinergic field. The absence of a GTP-induced shift, i.e., the ratio between the affinities measured in the presence and absence of 1 mM GTP indicates an antagonistic behavior of this new class of CPA analogues.


Assuntos
Adenosina/análogos & derivados , Antagonistas de Receptores Purinérgicos P1 , Adenosina/síntese química , Adenosina/farmacologia , Animais , Sítios de Ligação , Cristalografia por Raios X , Ensaio Radioligante , Ratos , Receptores Purinérgicos P1/metabolismo , Xantinas/farmacologia
15.
J Affect Disord ; 43(3): 195-205, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9186790

RESUMO

The contribution of genetic factors to the susceptibility for affective disorders has been firmly established. Recent reports found evidence for a susceptibility locus for affective disorders in 2 regions on chromosome 18. We describe 3 large Belgian pedigrees with multiple patients with affective disorders. Both chromosome 18 regions were investigated in the 3 families, using parametric and nonparametric segregation methods. In the pericentromeric region, all evidence was against a disease gene in our families. Also the data obtained for the distal part of 18q, argue against a genetic susceptibility factor in our sample.


Assuntos
Transtorno Bipolar/genética , Transtorno Bipolar/psicologia , Cromossomos Humanos Par 18 , Ligação Genética , Bélgica , Genótipo , Haplótipos , Heterozigoto , Humanos , Linhagem , Reação em Cadeia da Polimerase
16.
Eur J Biochem ; 245(3): 617-25, 1997 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9182997

RESUMO

We have characterized the primary structures of the predominant N-linked oligosaccharides on cellobiohydrolase I from the filamentous fungus Trichoderma reesei RUTC30. Different enzymatic and chromatographic techniques were used to analyze six oligosaccharides. The combined data showed that the fungal carbohydrates have a core structure that is identical to the mammalian N-linked core. In the bulk of the N-glycans, the alpha-1,3 arm is extended with two mannoses and a glucose, suggesting incomplete processing of the oligosaccharides in the endoplasmic reticulum. The alpha-1,6 arm shows a remarkable heterogeneity: in addition to alpha-1,2-Man and alpha-1,6-Man, the presence of a terminal mannose alpha-1,6-phosphodiester was observed. This latter substituent has not been characterized before on mannosidase-processed N-glycan and its function and synthesis pathway are entirely unknown. The predominant N-glycans on cellobiohydrolase I can be represented as follows: GlcMan8GlcNAc2, GlcMan7GlcNAc2, Man7GlcNAc2, ManPGlcMan7GlcNAc2, GlcMan5GlcNAc2 and Man5GlcNAc2.


Assuntos
Celulase/química , Proteínas Fúngicas/química , Oligossacarídeos/análise , Trichoderma/química , Sequência de Carboidratos , Celulose 1,4-beta-Celobiosidase , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Trichoderma/enzimologia
17.
FEBS Lett ; 405(1): 111-3, 1997 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-9094436

RESUMO

The primary structure of a novel phosphate-containing oligosaccharide, isolated from T. reesei cellobiohydrolase I, was determined by NMR techniques. The new compound has the same structure as GlcMan7GlcNAc2, but it is extended by one alpha-mannopyranosyl unit (Man-P) through a phosphate link. Three different heteronuclear (31P-1H) NMR techniques were used to prove that the phosphate links the glycosidic site of Man-P with C-6 of unit Man-B. The presence of mannoses linked through a phosphate diester resembles glycosyl synthesis in yeast.


Assuntos
Asparagina/análise , Celulase/química , Proteínas Fúngicas/química , Oligossacarídeos/análise , Trichoderma/enzimologia , Asparagina/química , Sequência de Carboidratos , Celulose 1,4-beta-Celobiosidase , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Oligossacarídeos/química
19.
Planta ; 201(3): 342-8, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19343412

RESUMO

The chemical composition of ethanolic and aqueous extracts from leafy galls produced after infection of Nicotiana tabacum L. plants with Rhodococcus fascians was drastically changed compared to uninfected controls. Chlorogenic acid was abundant both in uninfected and infected plants, but caffeic acid and another cinnamoyl analogue were new in leafy galls. The most pronounced product induced in leafy galls was identified as 7-O-methyl-6-O-beta-D-glucopyranosyl coumarin (7-methyl esculin). This is the first report of the presence of this coumarin derivative in tobacco. Interestingly, 7-methyl esculin did not accumulate in the presence of avirulent R. fascians strains nor was it found in leafy galls on other plant species. However, it did appear in crown galls induced by Agrobacterium tumefaciens on tobacco plants. Intriguingly, none of the phenolics known to accumulate in Solanaceae under pathogen attack were found in leafy galls. 7-Methyl esculin barely affected growth of R. fascians nor was it catabolized. Microscopical analysis showed that autofluorescent compounds were located mainly in the abundant meristematic regions of the leafy galls. We postulate that 7-methyl esculin might locally influence plant cell division.

20.
Biol Psychiatry ; 42(12): 1115-22, 1997 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9426881

RESUMO

Clinical anticipation has been reported in bipolar affective disorder (BPAD). The hypothesis that expanded trinucleotide repeats are related to anticipation and transmission pattern in families with bipolar affective disorder is tested in this study. Eighty-seven two-generation pairs of patients recruited from 29 bipolar families were analyzed. The repeat expansion detection method was used to detect CAG repeat expansions between successive generations. Significant changes in age at onset and episode frequency in successive generations were observed. Mean trinucleotide CAG repeat length between parental and offspring generation significantly increased when the phenotype increased in severity, i.e., changed from major depression, single episode or unipolar recurrent depression to BPAD. A parent-of-origin effect was also observed with a significant increase in median length CAG between G1 and G2 with maternal inheritance. This increase was observed notably in female offspring. Our findings indicate for the first time that expansion of CAG repeat length could explain the clinical observation of anticipation in families with BPAD. These results provide further support for expanded trinucleotide repeat sequences as risk factors in major affective disorders.


Assuntos
Transtorno Bipolar/genética , Repetições de Trinucleotídeos/genética , Adulto , Idade de Início , Transtorno Bipolar/epidemiologia , Transtorno Bipolar/psicologia , DNA/análise , DNA/genética , Feminino , Humanos , Masculino , Fenótipo
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