999 research outputs found
p518, a small floR plasmid from a South American isolate of Actinobacillus pleuropneumoniae
A small (3.9 kb) plasmid (p518), conferring resistance to florfenicol (MIC >8 μg/mL) and chloramphenicol (MIC >8 μg/mL) was isolated from an Actinobacillus pleuropneumoniae clinical isolate from Southeastern Brazil. To date, this is the smallest florfenicol resistance plasmid isolated from a member of the Pasteurellaceae. The complete nucleotide of this plasmid revealed a unique gene arrangement compared to previously reported florfenicol resistance plasmids found in other members of the Pasteurellaceae. In addition to the floR gene and a lysR gene, common to various florfenicol resistance plasmids, p518 also encodes strA and a partial strB sequence. An origin of replication (oriV) similar to that in the broad host range plasmid, pLS88, was identified in p518, and transformation into Escherichia coli MFDpir confirmed the ability to replicate in other species. Mobilisation genes appear to have been lost, with only a partial mobC sequence remaining, and attempts to transfer p518 from a conjugal donor strain (E. coli MFDpir) were not successful, suggesting this plasmid is not mobilisable. Similarly, attempts to transfer p518 into a competent A. pleuropneumoniae strain, MIDG2331, by natural transformation were also not successful. These results suggest that p518 may be only transferred by vertical descent
Anti-inflammatory, anti-proliferative and antioxidant profiles of selective cyclooxygenase-2 inhibition as chemoprevention for rat bladder carcinogenesis
PURPOSE: To evaluate the efficacy of a selective cyclooxygenase-2 (COX-2) inhibitor in rat bladder cancer chemoprevention, as well as to assess the relevance of inflammation, proliferation and oxidative stress in tumor growth and in its prevention.
RESULTS: The main findings were: (I) the incidence of carcinoma was: control: 0% (0/8); BBN: 65% (13/20); CEL: 0% (0/8) and BBN + CEL: 12.5% (1/8); (II) the mean tumor volume per rat with tumor and per tumor were significantly lower in the BBN + CEL group (21.2 and 5.3 +/- 0.4 mm(3)) vs. BBN (138.5 +/- 7.5 and 112.5 +/- 6.4 mm(3)); (III) the incidence of pre-neoplasic (hyperplasia and dysplasia) and neoplasic (papillary tumors and carcinoma in situ-CIS) lesions were notoriously reduced in the CEL + BBN treatment; (IV) CEL significantly reduced serum TGFbeta1 and CRP and increase TNFalpha and IL-1beta (p < 0.001); (V) CEL reduced MDA formation in serum (p < 0.001) and liver (p < 0.05) and also showed a trend to reduction in kidney.
METHODS: Drug treatments were performed during the first 8 w, followed by 12 w for tumor expression/prevention, in the following groups: control-vehicle; carcinogen-0.05% of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN); celecoxib (CEL)-10 mg/kg/day and preventive CEL + BBN. The bladders were analyzed for number and volume of tumor and nature of urothelium lesions. Serum was assessed for markers of inflammation, proliferation and redox status.
CONCLUSIONS: Celecoxib has demonstrated an outstanding inhibitory effect on bladder cancer chemoprevention, which might be due to its expected anti-inflammatory actions, as well as by anti-proliferatory and antioxidant actions. This data supports a pivotal role of cancer chemoprevention strategies based on COX-2 inhibition
Secondary syphilis presenting as leucoderma syphiliticum: case report and review
ABSTRACT Leucoderma syphiliticum (LS), originally described as syphilide pigmentaire, encompasses a spectrum of dyschromic lesions that emerge during the course of secondary syphilis. Very few case reports are available in modern biomedical databases. We present the case of a 57-year-old HIV-infected male patient who presented with several round to oval, non-scaling, slightly raised and well-demarcated hypochromic lesions scattered over the trunk, abdomen, dorsum, and arms. Prior non-treponemal tests were negative for syphilis, but novel studies yielded positive results at high titers. Skin lesions slowly regressed and the hypochromic areas repigmented a few weeks after benzathine penicillin G treatment. This is the first report of LS in an HIV-infected patient. A review of modern and ancient literature was performed. The present case report emphasizes the need for clinicians to have a heightened awareness of the varied and unusual clinical phenotypes of syphilis
Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli
Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts. Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins. Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets
Physical characterisation of an alginate/lysozyme nano-laminate coating and its evaluation on ‘coalho’ cheese shelf life
This work aimed at the characterisation of a nanolaminate
coating produced by the layer-by-layer methodology
and its evaluation on the preservation of ‘Coalho’ cheese.
Initially, five alternate layers of alginate and lysozyme were
assembled in an aminolysed/charged polyethylene terephthalate
(A/C PET) and physically characterised by UV/VIS
spectroscopy, contact angle, water vapour (WVTR) and oxygen
(OTR) transmission rates and scanning electron microscopy.
Afterwards, the same methodology was used to
apply the nano-laminate coating in ‘Coalho’ cheese and its
shelf life was evaluated during 20 days in terms of mass
loss, pH, lipid peroxidation, titratable acidity and microbial
count. UV/VIS spectroscopy and contact angle analyses
confirmed the layers’ deposition and the successful assembly
of nano-laminate coating on A/C PET surface. The coating
presented WVTR and OTR values of 1.03×10−3 and 1.28×
10−4 g m−2 s−1, respectively. After 20 days, coated cheese
showed lower values of mass loss, pH, lipidic peroxidation,
microorganisms’ proliferation and higher titratable acidity in
comparison with uncoated cheese. These results suggest that
gas barrier and antibacterial properties of alginate/lysozyme
nanocoating can be used to extend the shelf life of ‘Coalho’
cheese.The author Bartolomeu G. de S. Medeiros is recipient of a scholarship from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES-Brazil). The author Marthyna P. Souza is recipient of a scholarship from Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE, Brazil) and was recipient of a scholarship from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES/PDEE-Brazil). The authors Ana C. Pinheiro, Ana I. Bourbon and Miguel A. Cerqueira are recipients of a fellowship (SFRH/BD/48120/2008, SFRH/BD/73178/2010 and SFRH/BPD/72753/2010, respectively), supported by Fundacao para a Ciencia e Tecnologia, POPH-QREN and FSE (FCT, Portugal). Maria G. Carneiro-da-Cunha express is gratitude to the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for research grant. The present work was supported by CAPES/PROCAD/NF/1415/2007. The support of EU Cost Action FA0904 is gratefully acknowledged
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