Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Prev Chronic Dis ; 9: E14, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22172181

RESUMO

INTRODUCTION: Walking and bicycling are important but underused modes of transportation in the United States. Road design influences how much walking and bicycling takes place along streets and roads. Currently, numerous national policy initiatives, including Safe Routes to School and Complete Streets, are attempting to improve pedestrian and bicycling infrastructure and "friendliness." However, no state has completed a systematic assessment of its streets to determine how amenable they are to walking and bicycling. Our statewide study was undertaken to assess how accessible and friendly Hawaii roads are to these 2 activities. METHODS: We randomly selected street segments in Hawaii's 4 counties and then completed objective assessments using the Pedestrian Environmental Data Scan. We audited 321 segments, and interrater reliability was adequate across all measures. Streets were coded as high (42.4%) or low capacity (57.6%) depending on how much vehicular traffic the street was designed to accommodate. Outcome measures included street accommodations (ie, sidewalks and crossing aids) and pedestrian and bicyclist use. RESULTS: Most high-capacity streets had sidewalks (66%). These sidewalks were usually in good condition, contiguous, and had traffic control devices and pedestrian signals. Most low-capacity roads did not have sidewalks (63.4%). Bicycling facilities were limited (<10%) on both types of roads. Pedestrian and bicycle traffic was related to mixed use, including both residential and retail space, and to pedestrian and bicycling infrastructure. CONCLUSION: Road segments in Hawaii with more infrastructure and types of use, including single-family houses, apartment complexes, restaurants, office buildings, and industrial buildings, are used more by pedestrians and bicyclists.


Assuntos
Prevenção de Acidentes/métodos , Acidentes de Trânsito/estatística & dados numéricos , Ciclismo/lesões , Planejamento Ambiental/normas , Medição de Risco/organização & administração , Meio Social , Caminhada/lesões , Acidentes de Trânsito/prevenção & controle , Havaí/epidemiologia , Humanos , Reprodutibilidade dos Testes , Meios de Transporte/estatística & dados numéricos
2.
Geobiology ; 9(3): 266-79, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21356005

RESUMO

Fungi were isolated from fine granitic sediments, which were collected at 15 sampling points within a 20 m × 40 m area in front of the Damma glacier in the central Swiss Alps. From the 45 fungal isolates grown on nutrient-rich agar media at 4 °C, 24 isolates were selected for partial sequencing and identification based on the small subunit ribosomal DNA. Sequencing data revealed that the isolated fungi represented three fungal phyla and 15 species. The weathering potential of 10 of the 15 fungal species was tested with dissolution experiments using powdered granite material (<63 µm). The results showed that the zygomyceteous species Mucor hiemalis, Umbelopsis isabellina and Mortierella alpina dissolved the granite powder most efficiently due to the release of a variety of organic acids, mainly citrate, malate and oxalate. In particular, the high concentrations of Ca, Fe, Mg and Mn in the solutions clustered well with the high amounts of exuded citrate. This is the first report on fungi that were isolated from a non-vegetated glacier forefield in which the fungi's capabilities to dissolve granite minerals were examined.


Assuntos
Fungos/fisiologia , Sedimentos Geológicos/microbiologia , Camada de Gelo/microbiologia , Dióxido de Silício , Ácidos Carboxílicos/análise , Elementos Químicos , Fungos/isolamento & purificação , Análise de Componente Principal , Solo/química
3.
Accid Anal Prev ; 40(6): 2043-9, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19068313

RESUMO

Using a comprehensive database of police-reported accidents in Hawaii, we describe the nature of pedestrian accidents over the period 2002-2005. Approximately 36% of the accidents occur in residential areas, while another 34% occur in business areas. Only 41.7% of the pedestrian accidents occur at intersections. More pedestrian crashes occur at non-intersection locations-including midblock locations, driveways, parking lots, and other off roadway locations. Approximately 38.2% of the crashes occur at crosswalk locations, while proportionately more (61.8%) of the pedestrian accidents occur at non-crosswalk locations. Using this database the human, temporal, roadway, and environmental factors associated with being "at-fault" for both pedestrians and drivers are also examined. Using techniques of logistic regression, several different explanatory models are constructed, to identify the factors associated with crashes producing fatalities and serious injuries. Finally, two pedestrian models (drunk males and young boys) and one driver model (male commuters) are developed to provide further understanding of pedestrian accident causation. Drunk male pedestrians who were jaywalking were in excess of 10x more likely than other groups to be at-fault in pedestrian accidents. Young boys in residential areas were also more likely to be at-fault. Male commuters in business areas in the morning were also found to have higher odds of being classified at-fault when involved in pedestrian accidents. The results of this study indicate that there should be a combination of enforcement and educational programs implemented for both the pedestrian and drivers to show those at-fault the consequences of their actions, and to reduce the overall number of accidents.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Condução de Veículo , Caminhada , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Havaí/epidemiologia , Humanos , Lactente , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Assunção de Riscos , Fatores Sexuais , Adulto Jovem
4.
Accid Anal Prev ; 40(3): 894-904, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18460356

RESUMO

In 2005, Hawaii strengthened its pedestrian crosswalk laws. Previously, motorists had the option yielding or slowing down at a crosswalk and had to stop "only when necessary." The new law requires drivers to stop and yield to pedestrians at crosswalks. The purpose of this study is to examine patterns of violation and compliance with the law among both pedestrians and drivers. Observational studies at crosswalks were done in the Spring of 2006. In addition to reporting on overall rates of compliance, the characteristics of both pedestrians and drivers who either violate or comply with the law are described. While pedestrian compliance is higher than that of drivers, there are interesting differences to report in terms of age, gender, type of intersection, land use, and other factors. In addition to the results of a descriptive analysis, logistic regression models predicting the likelihood of violation of the crosswalk laws by either pedestrians or drivers, as a function of their characteristics, the type of intersection, and other factors are presented. The study finds that drivers tend to commit proportionately more violations than pedestrians, and violations are committed by a broader range of drivers than pedestrians. These results suggest that education and enforcement should be directed towards drivers. Future directions for research and enhancing the safety of pedestrians are described in a concluding section.


Assuntos
Acidentes de Trânsito/legislação & jurisprudência , Condução de Veículo/legislação & jurisprudência , Automóveis/legislação & jurisprudência , Assunção de Riscos , Caminhada/fisiologia , Acidentes de Trânsito/estatística & dados numéricos , Adolescente , Adulto , Fatores Etários , Condução de Veículo/estatística & dados numéricos , Automóveis/estatística & dados numéricos , Criança , Feminino , Havaí , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Fatores Sexuais
5.
Radiat Prot Dosimetry ; 125(1-4): 340-4, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17369266

RESUMO

Alanine and Radio-Photo-Luminescence (RPL) dosemeters are passive dosemeters used to monitor absorbed dose in all kind of radiation fields. However, up to now both dosemeter types are calibrated to photon sources only. In order to study the response of RPL and alanine dosemeters to mixed high-energy particle fields like those occurring at CERN's accelerators, an irradiation campaign at the CERN-EC High-Energy Reference field Facility (CERF-field) was performed. In this facility a copper target is irradiated by hadrons with a momentum of 120 GeV/c. Dosemeters were exposed to various mixed radiation fields by placing them at various positions on the surface of the target. In addition to the experiment FLUKA Monte Carlo simulations were carried out, which provide information concerning the energy deposition at the dosemeter locations. This paper compares the measurements with the simulation results and discusses the radiation field compositions present at the various dosemeter positions on the target.


Assuntos
Alanina/efeitos da radiação , Exposição Ambiental/análise , Medições Luminescentes/instrumentação , Fotometria/instrumentação , Monitoramento de Radiação/instrumentação , Proteção Radiológica/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Internacionalidade , Doses de Radiação , Ondas de Rádio , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
Mol Ecol ; 13(11): 3595-600, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15488015

RESUMO

Fine roots are expected to be important determinants of plant competition, but very little is known about the extent of root system overlap. Here, we describe the application of two highly variable plastide microsatellites to study the fine root distribution of tree individuals in a silver fir forest. We demonstrate that the spread of fine roots exceeds the width of above-ground parts, and that fine root overlaps among neighbouring trees are extensive both laterally and in depth. This approach will help to improve models of below-ground competition and will facilitate estimations of fine root biomass and thus of below-ground C pools.


Assuntos
Abies/anatomia & histologia , Abies/genética , Marcadores Genéticos , Raízes de Plantas , Genótipo , Repetições de Microssatélites , Folhas de Planta/fisiologia , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/fisiologia , Plastídeos/genética , Análise de Sequência de DNA
7.
Water Sci Technol ; 49(11-12): 77-82, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15303726

RESUMO

The feasibility of anaerobic ammonium oxidation (Anammox) in fixed-bed reactors was evaluated on laboratory and pilot scales. Using synthetic wastewater, the specific nitrogen removal rate was increased from 0.05-0.1 kgNm(-3)(reactor)d(-1) to 0.35-0.38 kgNm(-3)(reactor)d(-1) within a year (T= 22-27 degrees C) in all applications. However, the anammox activity was seriously and repeatedly inhibited at prolonged high nitrite concentrations (e.g. six days at 30-50 gNO2-Nm(-3)) and recovery was always a lengthy process. But even at a moderate nitrite concentration (11+/-10 gNO2-Nm(-3)), the observed specific growth rate was only 0.018 d(-1) at 26.4+/-0.8 degrees C, which corresponds to approximately 0.025 d(-1) at 30 degrees C (doubling time: 28 days). In a second experimental period for another 250 days, one of the laboratory reactors was fed with partially nitrified sludge liquors from a domestic wastewater treatment plant (WWTP). In this case, the specific elimination rate was as high as 3.5 kgNm(-3)(reactor)d(-1) at 26-27 degrees C. Independently of the feed, the average nitrogen elimination rate lay between 80-85% in all applications. An appropriate hydraulic design is essential to prevent clogging and local nitrite inhibition in fixed-bed reactors.


Assuntos
Bactérias Anaeróbias/fisiologia , Reatores Biológicos , Nitrogênio/isolamento & purificação , Compostos de Amônio Quaternário/metabolismo , Eliminação de Resíduos Líquidos/métodos , Oxirredução , Compostos de Amônio Quaternário/química , Movimentos da Água
8.
Mol Phylogenet Evol ; 21(2): 167-75, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11697913

RESUMO

The second intron in the mitochondrial gene nad1 was surveyed using PCR, DNA sequencing, or Southern hybridization in 323 species (313 genera, 212 families) of seed plants. The intron was absent in all 22 species (22 genera, 8 families) of non-Pinaceae conifers studied, in Welwitschia mirabilis, and in seven angiosperms. Whereas absence of the intron in seven angiosperms and Welwitschia is likely due to seven independent losses when evaluated against the recently published multigene phylogenies, the lack of the intron in all non-Pinaceae conifers can be best explained by a single loss. These data suggest that the non-Pinaceae conifers represent a monophyletic group. We also conducted a phylogenetic analysis of seed plants using a combined data set of the partial exon and intron sequences of nad1 generated from this study and published sequences of mitochondrial cox1 and small subunit (SSU) rDNA, chloroplast rbcL, and nuclear 18S rDNA. The results supported the split of conifers into two groups: Pinaceae and non-Pinaceae conifers. The Gnetales were sister to Pinaceae, in agreement with the conclusion from other recent molecular phylogenetic studies that refute the anthophyte hypothesis.


Assuntos
Cycadopsida/genética , Proteínas Mitocondriais , Pinaceae/genética , Ribulose-Bifosfato Carboxilase , Sequência de Bases , Núcleo Celular/genética , Cycadopsida/classificação , DNA Mitocondrial/genética , DNA de Plantas/química , DNA de Plantas/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Evolução Molecular , Genes de Plantas/genética , Íntrons/genética , Dados de Sequência Molecular , NADH Desidrogenase/genética , Filogenia , Pinaceae/classificação , Proteínas de Plantas/genética , RNA Ribossômico/genética , RNA Ribossômico 18S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico
9.
Mol Ecol ; 10(8): 2079-87, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11555251

RESUMO

Fine roots of trees are intensively used as indicators to assess soil alterations, e.g. those owing to atmospheric inputs of acidifying substances, but their identification to species with morphological criteria is difficult. In this study, we established molecular techniques in order to identify fine roots of the 30 most common tree species of the Alps. We developed a protocol for efficient isolation of DNA from fine roots with extraction of DNA in the presence of polyvinylpyrrolidone (PVP) and polyvinylpolypyrrolidone (PVPP). The trnL (UAA) intron of plastid DNA was used as a marker for fine root identification. We amplified and sequenced this intron with plant universal primers. The size of the sequences ranged from 444 to 672 bp. A synoptic key for species identification was designed on the basis of restriction fragment patterns predicted from sequence data. Using the restriction enzyme TaqI as key enzyme, and where necessary HinfI, RsaI and CfoI, 16 taxa, including Picea abies, Larix decidua, Abies alba, and Fagus sylvatica, the dominant tree species of the Alpine region could be identified by agarose gel electrophoresis of restriction fragments. Fourteen taxa could be identified to the genus level, among them Quercus, Salix and Populus species. In a field study, conducted in a 20 x 30 m plot of a mixed forest with five tree species, fine roots of 43 out of 46 samples were identified and their distributions were mapped. These results demonstrate the utility of our DNA extraction method and of the trnL intron for the identification of fine tree roots.


Assuntos
Raízes de Plantas/classificação , Árvores/classificação , DNA de Plantas/genética , DNA de Plantas/isolamento & purificação , Íntrons , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Suíça , Árvores/genética , Árvores/metabolismo
10.
Environ Pollut ; 114(2): 223-33, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11504345

RESUMO

Norway spruce seedlings were grown under greenhouse conditions in Rootrainers with a vermiculite-peat moss mixture under various N-regimes for 6 months. Either ammonium or nitrate was applied in loads of 100 or 800 kg N ha(-1) year(-1) to seedlings which were either non-mycorrhizal or inoculated with the mycorrhizal fungi Hebeloma crustuliniforme or Laccaria bicolor. The use of increasing N loads enhanced shoot and total biomass, whereas root/shoot ratio, number of short roots and mycorrhization decreased. A significant enhancement of the concentration and content was obvious for the element N, whereas a significant decrease was obvious for P and Zn concentrations. The use of ammonium, as opposed to nitrate, significantly enhanced the biomass and the numbers of short roots, and reduced the root/shoot ratios, but did not influence the mycorrhization. It further significantly enhanced the N concentrations in roots and shoots. Fungal inoculation with H. crustuliniforme or L. bicolor compared to non-inoculated controls significantly enhanced shoot and total biomass, but reduced root/shoot ratios. The mycorrhization further significantly enhanced N and P concentrations and contents, but reduced Mn. Overall, the mycorrhization improved the P nutrition of the seedlings independently on the applied N loads or N sources. Dose response curves using ammonium nitrate as N source with a maximum load of 1600 kg N ha(-1) year(-1) applied on seedlings associated with H. crustuliniforme revealed that the maximum growth was reached at a load of 800 kg N ha(-1) year(-1) with a simultaneous decrease of the mycorrhization. In both shoots and roots, N concentrations increased constantly with increasing N loads, while P, Ca, and Zn concentrations decreased constantly.


Assuntos
Poluentes Atmosféricos/farmacologia , Nitrogênio/farmacologia , Picea/fisiologia , Raízes de Plantas/microbiologia , Biomassa , Fungos/fisiologia , Picea/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Plantas , Compostos de Amônio Quaternário/química
11.
Environ Pollut ; 108(2): 121-8, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-15092942

RESUMO

Norway spruce seedlings colonized with Hebeloma crustuliniforme were grown in growth pouches. After formation of ectomycorrhizas, the seedlings were exposed to Al or the heavy metals Cd, Cu, Ni, or Zn at various concentrations for 5 weeks to estimate the detection limits of metals with X-ray microanalysis in the cryo-scanning electron microscope. When the lowest metal concentrations (1 mM Al(3+), 0.1 mM Cd(2+), 0.2 mM Cu(2+), 0.5 mM Ni(2+), 2 mM Zn(2+)) were applied, only Al and Zn were detected at low X-ray counts in the ectomycorrhizas. After application of 10-fold higher metal concentrations, distinct metal accumulation patterns were observed. Cd was detected predominantly in the Hartig net, Al and Ni in the Hartig net and in the cell walls of the cortex, and Zn in the Hartig net, the cortical cell walls and the fungal mantle. Cu was not detected at all. By combining X-ray microanalysis with absolute metal concentrations found in the roots, the estimated detection limits of X-ray microanalysis were: Al> or =0.86 mg g(-1), Cd> or =0.26 mg g(-1), Ni> or =1.30 mg g(-1), and Zn> or =0.54 mg g(-1), whereas Cu was not detectable even at root concentrations of 0.47 mg g(-1). Treatments with the highest metal concentrations showed high X-ray counts of metals in cells of the stele but reduced concentrations of the macronutrients K, Mg, and P in roots, indicating a possible disturbance of root and ectomycorrhizal function.

12.
Zentralbl Veterinarmed A ; 44(9-10): 573-8, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9465777

RESUMO

From 12 bitches of various breeds with fertile oestrus cycles faecal samples were collected daily from the onset of pro-oestrus till 20 days after the start of vulval bleeding, then once per week till about 1 week before term. Immunoreactive progesterone metabolites were extracted from the samples using methanol and measured using immunoassays. In a first experiment four different assays were compared in regard to the amounts of immunoreactive substances measured: the enzyme immunoassay against 20-oxo-3-hydroxypregnanes showed twice to four times higher values of immunoreactive material than another using an antibody against 6 beta-hydroxyprogesterone. An enzyme immunoassay for pregnanediol measured only low concentrations of immunoreactive material. Also a radio immunoassay using an antibody against 11 beta-hydroxyprogesterone detected only small amounts of reacting material. High performance liquid chromatography showed that in faeces of bitches the immunoreactive progesterone metabolites were present in unconjugated form, mainly as 3 alpha/beta hydroxylated progestagens with a 20-oxo group. In the second experiment the samples were measured with the assay system using the 20-oxo-3-hydroxypregnane antibody. A few days before mating the concentration of progesterone metabolites increased, reaching 5.77 mumol/kg faeces (median) at the day of mating. High levels (10.45 mumol/kg faeces) were measured till the end of the first month after mating. Thereafter, the concentrations decreased, reaching 2.68 mumol/kg (median) at the end of the second month.


Assuntos
Cães/metabolismo , Fezes/química , Progesterona/metabolismo , Progestinas/análise , Animais , Cromatografia Líquida de Alta Pressão/veterinária , Reações Cruzadas , Cães/fisiologia , Estro/fisiologia , Feminino , Imunoensaio/veterinária , Progesterona/análise , Progesterona/imunologia , Progestinas/imunologia
13.
Tree Physiol ; 16(8): 705-11, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14871693

RESUMO

Norway spruce (Picea abies (L.) Karst.) seedlings growing in a growth pouch system were used to investigate the effects of the ectomycorrhizal fungus Hebeloma crustuliniforme (Bull. ex St. Amans) Quél. and various Cs/K ratios on the uptake of (134)Cs, expressed as a percentage of the total amount of (134)Cs supplied. The amount of (134)Cs taken up by seedlings increased with increasing Cs/K ratio. At a Cs/K ratio of 0.1, uptake of (134)Cs ranged between 7.2 and 7.3% and was independent of ectomycorrhizal status, whereas at Cs/K ratios >/= 1 uptake of (134)Cs varied from 8.1 to 11.1% for ectomycorrhizal and from 10.4 to 14.4% for non-inoculated plants. Ectomycorrhizal seedlings contained a lower concentration of (134)Cs than non-inoculated seedlings. Among plant parts, the amount of (134)Cs was significantly lower in needles and lateral roots of ectomycorrhizal seedlings compared with non-inoculated seedlings. Among fungal and seedling tissues, highest X-ray net counts of (133)Cs were measured in fungal hyphae of ectomycorrhizal mantles. X-Ray net counts of (133)Cs in lateral roots of ectomycorrhizal and non-inoculated plants were similar, but 5 to 10 times higher than in main roots and needles, suggesting an accumulation of (133)Cs in lateral roots and slow translocation to other plant parts. In contrast, X-ray net counts of K indicated that K was readily mobilized from lateral roots to main roots and needles. Elemental mapping showed a relatively homogeneous distribution of (133)Cs within the root.

14.
Environ Pollut ; 93(1): 1-8, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-15091363

RESUMO

Microorganisms play an important role in the fixation of radionuclides in forest soils. In particular, fungi have the capacity to absorb and translocate radionuclides. The role of the ectomycorrhizal fungus Hebeloma crustuliniforme in the uptake of radiocaesium (134Cs) and radiostrontium (85Sr) into seedlings of Norway spruce (Picea abies) was investigated in a pouch test system. Inoculated and non-inoculated seedlings; seedlings inoculated during 8 and 15 weeks; seedlings exposed during 2 and 3 weeks to the radioactive solution; and seedlings grown under low and high ammonium conditions prior to the application of the radionuclides were compared. The final 134Cs and 85Sr activity was determined in fine-roots, main-roots, stems and needles. The results showed that ectomycorrhizae reduced the uptake of 134Cs and 85Sr. The degree of ectomycorrhization was of crucial importance and seemed to be governed by the period during which ectomycorrhizae were allowed to develop and by the ammonium concentration in the nutrient solution. The radionuclide uptake increased with increasing exposure time. Both radionuclides were predominantly accumulated in fine-roots. However, needles proved to describe best the result of net root uptake and translocation to the shoot. The uptake-and and translocation-rates of 85Sr were smaller than those of 134Cs. It is assumed that the translocation is coupled with the intensity of water fluxes through the xylem and that 85Sr is more readily adsorbed into mycelium or plant tissue relative to 134Cs. The effect of high ammonium growth conditions was overcome by the effect of ectomycorrhization, except in needles with a very large biomass which behaved as a strong sink and led to a high accumulation of 134Cs.

15.
Appl Environ Microbiol ; 60(9): 3105-11, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7944356

RESUMO

DNA sequences of single-copy genes coding for chitin synthases (UDP-N-acetyl-D-glucosamine:chitin 4-beta-N-acetylglucosaminyltransferase; EC 2.4.1.16) were used to characterize ectomycorrhizal fungi. Degenerate primers deduced from short, completely conserved amino acid stretches flanking a region of about 200 amino acids of zymogenic chitin synthases allowed the amplification of DNA fragments of several members of this gene family. Different DNA band patterns were obtained from basidiomycetes because of variation in the number and length of amplified fragments. Cloning and sequencing of the most prominent DNA fragments revealed that these differences were due to various introns at conserved positions. The presence of introns in basidiomycetous fungi therefore has a potential use in identification of genera by analyzing PCR-generated DNA fragment patterns. Analyses of the nucleotide sequences of cloned fragments revealed variations in nucleotide sequences from 4 to 45%. By comparison of the deduced amino acid sequences, the majority of the DNA fragments were identified as members of genes for chitin synthase class II. The deduced amino acid sequences from species of the same genus differed only in one amino acid residue, whereas identity between the amino acid sequences of ascomycetous and basidiomycetous fungi within the same taxonomic class was found to be approximately 43 to 66%. Phylogenetic analysis of the amino acid sequence of class II chitin synthase-encoding gene fragments by using parsimony confirmed the current taxonomic groupings. In addition, our data revealed a fourth class of putative zymogenic chitin synthesis.


Assuntos
Quitina Sintase/genética , Fungos/enzimologia , Fungos/genética , Genes Fúngicos , Variação Genética , Sequência de Aminoácidos , Ascomicetos/classificação , Ascomicetos/enzimologia , Ascomicetos/genética , Sequência de Bases , Basidiomycota/classificação , Basidiomycota/enzimologia , Basidiomycota/genética , DNA Fúngico/genética , Fungos/classificação , Íntrons , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Simbiose , Árvores/microbiologia
16.
Dtsch Med Wochenschr ; 117(16): 603-6, 1992 Apr 16.
Artigo em Alemão | MEDLINE | ID: mdl-1568426

RESUMO

The effect of the angiotensin-converting enzyme (ACE) inhibitor quinapril on myocardial ischaemia was tested in a randomized double-blind cross-over study of 16 men (mean age 62 [44-75] years) with angiographically demonstrated coronary heart disease, exercise-induced ST-segment depression and stable angina. Exercise ECGs were recorded before and 4 hours after a single dose of 10 mg quinapril and after a 14-day course of 10 mg quinapril twice daily. The single dose decreased the average ST-segment depression from 1.12 mV (placebo) to 0.74 mV (P less than 0.05); after 14 days on quinapril the ST-segment depression decreased from 0.91 mV (placebo) to 0.72 mV (P less than 0.05). While heart rate remained unchanged the average resting arterial blood pressure fell from 136/80 to 120/74 mmHg (P less than 0.05) after a single dose and from 141/83 to 127/78 mmHg (P less than 0.05) after 14 days on the drug. These data indicate that ACE inhibitors should be considered as a means of treating coronary heart disease and angina.


Assuntos
Angina Pectoris/tratamento farmacológico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Isoquinolinas/uso terapêutico , Tetra-Hidroisoquinolinas , Administração Oral , Idoso , Angina Pectoris/diagnóstico , Pressão Sanguínea/efeitos dos fármacos , Doença das Coronárias/diagnóstico , Doença das Coronárias/tratamento farmacológico , Método Duplo-Cego , Eletrocardiografia/efeitos dos fármacos , Teste de Esforço , Humanos , Masculino , Pessoa de Meia-Idade , Quinapril , Fatores de Tempo
17.
FEBS Lett ; 286(1-2): 67-70, 1991 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-1713858

RESUMO

A heteroplasmic point mutation (transition A to G at position 3243 in the mitochondrial tRNA(Leu(UUR)) gene is indicative for myo-encephalopathy with lactic acidosis and stroke-like episodes (MELAS). Decreased respiratory chain complex activities measured in different tissues from four patients with MELAS syndrome do not correlate with the proportion of mutated mitochondrial genome.


Assuntos
Acidose Láctica/genética , Encefalopatias/genética , Transtornos Cerebrovasculares/genética , RNA de Transferência de Leucina/genética , RNA/genética , Acidose Láctica/complicações , Acidose Láctica/metabolismo , Adulto , Southern Blotting , Encefalopatias/complicações , Encefalopatias/metabolismo , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Humanos , Masculino , Mitocôndrias/metabolismo , Mutação , Oxirredutases/metabolismo , Consumo de Oxigênio , RNA Mitocondrial , Síndrome
18.
J Clin Chem Clin Biochem ; 28(4): 241-50, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2162908

RESUMO

We performed restriction analysis and Southern blotting of the muscle mitochondrial DNA from 34 patients suffering from different myopathies. In 13/21 patients with chronic progressive external ophthalmoplegia the muscle mitochondrial DNA was shown to be heteroplasmic. Further mapping by use of several restriction enzymes yielded large deletions in muscles from 10/13 chronic progressive external ophthalmoplegia patients. Most of the deletions spanned large parts of the mitochondrial genome, leading to loss of mitochondrial genes encoding several subunits of the respiratory chain complexes I (NADH-dehydrogenase), IV (cytochrome c oxidase) and V (ATP-synthetase), as well as of several tRNAs. Comparison of the mapping data with the histochemical and biochemical results did not provide a clear correlation between the location of the mitochondrial genetic defects and the functional deficiencies of the affected respiratory chain complexes. In the majority of patients with chronic progressive external ophthalmoplegia, but without a family history of the disease, restriction analysis reveals large mutations of the mitochondrial genome, while other methods are necessary for the localization of defects in all cases with maternal transmission of the disease. The same holds true for all other kinds of mitochondrial myopathies based on defects within the nuclear DNA or on derangements of the "cross-talk" between the nuclear and the mitochondrial genomes.


Assuntos
Encefalopatias Metabólicas/diagnóstico , DNA Mitocondrial/genética , Doença de Leigh/diagnóstico , Doenças Musculares/diagnóstico , Adulto , Idoso , Biópsia , Southern Blotting , Células Cultivadas , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Fibroblastos/fisiologia , Biblioteca Genômica , Humanos , Síndrome de Kearns-Sayre/diagnóstico , Síndrome de Kearns-Sayre/genética , Doença de Leigh/genética , Masculino , Pessoa de Meia-Idade , Mitocôndrias Musculares/fisiologia , Músculos/patologia , Doenças Musculares/genética , Mutação , NADH Desidrogenase/genética , NADH Desidrogenase/metabolismo , Oftalmoplegia/diagnóstico , Oftalmoplegia/genética , Mapeamento por Restrição , Succinato Citocromo c Oxirredutase/genética , Succinato Citocromo c Oxirredutase/metabolismo
19.
Epilepsia ; 27(5): 559-62, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3093213

RESUMO

This study was initiated to examine the influence of valproic acid (VPA) on serum carnitine, as well as the possible etiological role of carnitine in VPA-induced fatal hepatotoxicity. Free, total, and short-chain acylcarnitine were measured in the serum of 21 pediatric patients receiving VPA therapy, 21 healthy matched controls, and 21 patients receiving various antiepileptic drugs other than VPA. The free carnitine level was lowest in the VPA group (p less than 0.05), and the short-chain acylcarnitine/free carnitine ratio was highest in the VPA group (p less than 0.01). Patients receiving VPA polytherapy had lower total carnitine values than patients receiving VPA monotherapy (p less than 0.05). No correlation was found between serum ammonia and VPA drug levels. A 3 1/2-year-old girl developed hepatic failure under VPA therapy. Her serum carnitine values were normal. Despite the oral intake of L-carnitine this patient died. In this case, apparently VPA-induced hepatotoxicity was not associated with carnitine deficiency. The reduction of carnitine in the serum of VPA-treated patients is most probably due to alterations of fatty acid metabolism. However, neither primary carnitine deficiency nor VPA-induced secondary carnitine deficiency can be the only reason for the VPA-induced fatal hepatotoxicity.


Assuntos
Carnitina/sangue , Ácido Valproico/uso terapêutico , Adolescente , Adulto , Anticonvulsivantes/uso terapêutico , Criança , Pré-Escolar , Quimioterapia Combinada , Epilepsia/sangue , Epilepsia/tratamento farmacológico , Feminino , Humanos , Masculino , Ácido Valproico/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...