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排序方式: 共有180条查询结果,搜索用时 281 毫秒
31.
Mariana Volpe Arnoni Claudete Rodrigues Paula Marcos Ereno Auler Cirilo Cesar Naozuka Simões Shirley Nakano Maria Walderez Szeszs Márcia de Souza Carvalho Melhem Virgínia Bodelão Richini Pereira Hans Garcia Garces Eduardo Bagagli Eriques Gonçalves Silva Melissa Ferreira de Macêdo Luciana da Silva Ruiz 《Mycopathologia》2018,183(6):941-949
Fusarium species have emerged as responsible for a broad spectrum of infections, including superficial, locally invasive and disseminated ones, especially in the hospital environment. Since there are few reports of invasive and disseminated fusariosis in children, the aim of this study was to report four cases of nosocomial infection caused by this microorganism in children with cancer hospitalized in a public children’s hospital located in Brazil. Two of these patients were female and two were male. All patients presented febrile neutropenia, while three patients had acute lymphocytic leukemia and one patient had Wilms’ tumor as underlying disease. In two cases, fungi were isolated from blood and identified as Fusarium oxysporum species complex after phenotypic and genotypic studies, while in two other cases fungi were isolated from skin biopsies and identified as Fusarium solani species complex. One patient died 12 days after the onset of cutaneous lesions. All isolates, after susceptibility testing, presented high levels of minimum inhibitory concentration for itraconazole, voriconazole and amphotericin B. Considering the emergence of filamentous fungi as etiologic agents of nosocomial infections, health professionals should be aware of the problems these infections, especially fungal ones, may cause to debilitated patients. 相似文献
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Rosimeire Borges Moreira Lacerda Thamires Rodrigues Freitas Mário Machado Martins Thaise Lara Teixeira Cláudio Vieira da Silva Pamela Aparecida Candido Ronaldo Junio de Oliveira Claudio Viegas Júnior Vanderlan da Silva Bolzani Amanda Danuello Marcos Pivatto 《Bioorganic & medicinal chemistry》2018,26(22):5816-5823
Leishmaniasis is one of the most important neglected tropical diseases (NTDs) that are especially common among low-income populations in developing regions of Africa, Asia, and the Americas. Many natural products, particularly alkaloids, have been reported to have inhibitory activity against arginase, the key enzyme in the pathology caused by Leishmania sp. In this way, piperidine alkaloids (–)-cassine (1), (–)-spectaline (2), (–)-3-O-acetylcassine (3), and (–)-3-O-acetylspectaline (4) were isolated from Senna spectabilis flowers. These compounds (1/2 and 3/4) initially present as homologous mixtures were separated by high performance liquid chromatography and evaluated against the promastigote phase of Leishmania amazonensis. In addition, molecular docking simulations were implemented in order to probe the binding modes of the ligands 1–4 to the amino acids in the active site of L. amazonensis arginase. Alkaloid 2 (IC50 15.81?μg?mL?1) was the most effective against L. amazonensis. Compounds 2 and 4, with larger side chain, were more effective against the parasite than compounds 1 and 3. The cell viability test on Vero cells revealed that compound 2 (CC50 66.67?μg?mL?1) was the most toxic. The acetyl group in the 3-O position of the parent structures reduced the leishmanicidal activity and the toxicity of the alkaloids. Further, molecular docking suggested that Asn143 is essential for arginase to interact with (–)-spectaline-derived compounds, which agreed with the IC50 measurements. Our findings revealed that S. spectabilis is an important source of piperidine alkaloids with leishmanicidal activity. Moreover, the natural compound 3 has been isolated for the first time. Experimental investigation combined with theoretical study advances knowledge about the enzyme binding site mode of interaction and contributes to the design of new bioactive drugs against Leishmania infection. 相似文献
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Molecular evolution of mitochondrial 12S RNA and cytochrome b sequences in the pantherine lineage of Felidae 总被引:4,自引:2,他引:2
DNA sequence comparisons of two mitochondrial DNA genes were used to infer
phylogenetic relationships among 17 Felidae species, notably 15 in the
previously described pantherine lineage. The polymerase chain reaction
(PCR) was used to generate sequences of 358 base pairs of the mitochondrial
12S RNA gene and 289 base pairs of the cytochrome b protein coding gene.
DNA sequences were compared within and between 17 felid and five nonfelid
carnivore species. Evolutionary trees were constructed using phenetic,
cladistic, and maximum likelihood algorithms. The combined results
suggested several phylogenetic relationships including (1) the recognition
of a recently evolved monophyletic genus Panthera consisting of Panthera
leo, P. pardus, P. onca, P. uncia, P. tigris, and Neofelis nebulosa; (2)
the recent common ancestry of Acinonyx jubatus, the African cheetah, and
Puma concolor, the American puma; and (3) two golden cat species, Profelis
temmincki and Profelis aurata, are not sister species, and the latter is
strongly associated with Caracal caracal. These data add to the growing
database of vertebrate mtDNA sequences and, given the relatively recent
divergence among the felids represented here (1-10 Myr), allow 12S and
cytochrome b sequence evolution to be addressed over a time scale different
from those addressed in most work on vertebrate mtDNA.
相似文献
35.
Sea urchin Hox genes: insights into the ancestral Hox cluster 总被引:3,自引:0,他引:3
We describe the Hox cluster in the radially symmetric sea urchin and
compare our findings to what is known from clusters in bilaterally
symmetric animals. Several Hox genes from the direct-developing sea urchin
Heliocidaris erythrogramma are described. CHEF gel analysis shows that the
Hox genes are clustered on a < or = 300 kilobase (kb) fragment of DNA,
and only a single cluster is present, as in lower chordates and other
nonvertebrate metazoans. Phylogenetic analyses of sea urchin, amphioxus,
Drosophila, and selected vertebrate Hox genes confirm that the H.
erythrogramma genes, and others previously cloned from other sea urchins,
belong to anterior, central, and posterior groups. Despite their radial
body plan and lack of cephalization, echinoderms retain at least one of the
anterior group Hox genes, an orthologue of Hox3. The structure of the
echinoderm Hox cluster suggests that the ancestral deuterostome had a Hox
cluster more similar to the current chordate cluster than was expected Sea
urchins have at least three Abd-B type genes, suggesting that Abd-B
expansion began before the radiation of deuterostomes.
相似文献
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39.
Pseudomonas aeruginosa diaminopimelate decarboxylase: evolutionary relationship with other amino acid decarboxylases 总被引:1,自引:0,他引:1
Martin C; Cami B; Yeh P; Stragier P; Parsot C; Patte JC 《Molecular biology and evolution》1988,5(5):549-559
The lysA gene encodes meso-diaminopimelate (DAP) decarboxylase
(E.C.4.1.1.20), the last enzyme of the lysine biosynthetic pathway in
bacteria. We have determined the nucleotide sequence of the lysA gene from
Pseudomonas aeruginosa. Comparison of the deduced amino acid sequence of
the lysA gene product revealed extensive similarity with the sequences of
the functionally equivalent enzymes from Escherichia coli and
Corynebacterium glutamicum. Even though both P. aeruginosa and E. coli are
Gram-negative bacteria, sequence comparisons indicate a greater similarity
between enzymes of P. aeruginosa and the Gram- positive bacterium C.
glutamicum than between those of P. aeruginosa and E. coli enzymes.
Comparison of DAP decarboxylase with protein sequences present in data
bases revealed that bacterial DAP decarboxylases are homologous to mouse
(Mus musculus) ornithine decarboxylase (E.C.4.1.1.17), the key enzyme in
polyamine biosynthesis in mammals. On the other hand, no similarity was
detected between DAP decarboxylases and other bacterial amino acid
decarboxylases.
相似文献
40.