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1.
Infect Genet Evol ; 92: 104862, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33848685

RESUMO

South American fur seals (Arctocephalus australis) are believed to reach the coast of Rio Grande do Sul (RS) through sea currents. They live in colonies and are frequently found resting on the beach. However, it is also common to find dead pinnipeds on beaches, sharing the environment with humans, domestic animals and other wild species on the coast and facilitating the transmission of pathogens. In the present study, a metagenomic approach was applied to evaluate the viral diversity in organs of fur seals found deceased along the coast of the state of RS, southern Brazil. The lungs and spleens of 29 animals were collected, macerated individually, pooled separately (one pool for lungs and another for spleens) and sequenced using the Illumina MiSeq platform. Sequences more closely related to members of the Anelloviridae and Circoviridae families were detected. Nine putative new species of anellovirus and one putative new genus, named Nitorquevirus, were described. Additionally, the circovirus sequences found in the lungs of A. australis have a common ancestor with PCV3, a proposed swine pathogen. Our study expanded the knowledge about viral communities in pinnipeds and could be useful for monitoring new viruses and potential viral sharing among wildlife, domestic animals, and humans.


Assuntos
Otárias/virologia , Pulmão/virologia , Baço/virologia , Viroma/genética , Anelloviridae/genética , Animais , Brasil , Circovirus/genética , Metagenômica/métodos , Filogenia
2.
J Immigr Minor Health ; 20(5): 1190-1196, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28952005

RESUMO

Italian-born migrants (post-WWII) are the largest non-English-speaking background migrant group in South Australia. A cross-sectional, inter-country comparison using independent samples (40-69 years of age) from two (one in Australia, one in Italy) similar risk factor and chronic disease surveillance systems. None of the three groups (Italians, Australian-born and Italian-born Australians) had definitively worse health although the Italians had high rates for four of the seven risk factors reported (current high blood pressure, current high cholesterol, current smoking, eating less than five fruit and/or vegetables per day) than Australian-born and Italian-born Australians. Italian-born Australians had higher rates for insufficient physical activity, overweight/obese, poor self-reported health and diabetes. Australian respondents were more likely to report having two or more drinks of alcohol per day. Issues facing an ageing population require appropriate health care needs and an assessment of structural or cultural barriers to health services.


Assuntos
Doenças Cardiovasculares/etnologia , Nível de Saúde , Adulto , Idoso , Consumo de Bebidas Alcoólicas/etnologia , Austrália/epidemiologia , Índice de Massa Corporal , Comparação Transcultural , Estudos Transversais , Diabetes Mellitus/etnologia , Dieta , Exercício Físico , Feminino , Inquéritos Epidemiológicos , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade/etnologia , Fatores de Risco , Fumar/etnologia , Fatores Socioeconômicos
3.
Data Brief ; 8: 1120-1126, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30656205

RESUMO

Performance and load normalized coefficients, deriving from an experimental campaign of measurements conducted at the large scale wind tunnel of the Politecnico di Milano (Italy), are presented with the aim of providing useful benchmark data for the validation of numerical codes. Rough data, derived from real scale measurements on a three-bladed Troposkien vertical-axis wind turbine, are manipulated in a convenient form to be easily compared with the typical outputs provided by simulation codes. The here proposed data complement and support the measurements already presented in "Wind Tunnel Testing of the DeepWind Demonstrator in Design and Tilted Operating Conditions" (Battisti et al., 2016) [1].

4.
J Pediatr Hematol Oncol ; 24(5): 394-6, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12142790

RESUMO

Anewborn with a transient myeloproliferative disorder and a myeloid/natural killer cell leukemia phenotype is described. The blasts expressed CD7, CD33, CD34, CD56, and CD117 but did not react with cytoplasmic myeloperoxidase and were negative for cy CD22, HLA-DR, and CD90 expression. No megakaryoblastic surface markers were identified. The blast population disappeared from the peripheral blood and bone marrow within 2 months, but hepatomegaly and recurrent respiratory insufficiency persisted. The patient died of unilateral pneumonia in the third month of life. Neither extramedullary infiltration nor other hematologic signs of disease progression were found.


Assuntos
Antígenos CD7/análise , Antígeno CD56/análise , Células Matadoras Naturais/patologia , Leucemia Mieloide/congênito , Células Mieloides/patologia , Transtornos Mieloproliferativos/patologia , Evolução Fatal , Feminino , Humanos , Imunofenotipagem , Recém-Nascido , Leucemia Mieloide/patologia , Masculino , Transtornos Mieloproliferativos/imunologia , Gravidez
5.
Ann N Y Acad Sci ; 934: 464-72, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11460662

RESUMO

In gas turbine cooling design, techniques for heat extraction from the surfaces exposed to the hot stream are based on the increase of the inner heat transfer areas and on the promotion of the turbulence of the cooling flow. This is currently obtained by casting periodic ribs on one or more sides of the serpentine passages into the core of the blade. Fluid dynamic and thermal behaviour of the cooling flow have been extensively investigated by means of experimental facilities and many papers dealing with this subject have appeared in the latest years. The evaluation of the average value of the heat transfer coefficient most of the time is inferred from local measurements obtained by various experimental techniques. Moreover the great majority of these studies are not concerned with the overall average heat transfer coefficient for the combined ribs and region between them, but do focus just on one of them. This paper presents an attempt to collect information about the average Nusselt number inside a straight ribbed duct. Series of measurements have been performed in steady state eliminating the error sources inherently connected with transient methods. A low speed wind tunnel, operating in steady state flow, has been built to simulate the actual flow condition occurring in a rectilinear blade cooling channel. A straight square channel with 20 transverse ribs on two sides has been tested for Re of about 3 x 10(4), 4.5 x 10(4) and 6 x 10(4). The ribbed wall test section is electrically heated and the heat removed by a stationary flow of known thermal and fluid dynamic characteristics.

6.
Am J Respir Crit Care Med ; 163(6): 1415-9, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11371411

RESUMO

Asthma education decreases the number of emergency visits in specific subgroups of patients with asthma. However, it remains unknown whether this improvement is related only to the use of an action plan alone or to other components of the educational intervention. A total of 126 patients consulting urgently for an acute asthma exacerbation were recruited; 98 completed the study. The first 45 patients were assigned to Group C (control; usual treatment). Thereafter, patients were randomized to either Group LE (limited education; teaching of the inhaler technique plus self- action plan given by the on call physician) or Group SE (same as group LE plus a structured educational program emphasizing self-capacity to manage asthma exacerbations). At baseline, there was no difference between groups in asthma morbidity, medication needs, or pulmonary function. After 12 mo, only Group SE showed a significant improvement in knowledge, willingness to adjust medications, quality of life scores, and peak expiratory flows. In the last 6 mo, the number of unscheduled medical visits for asthma was significantly lower in Group SE in comparison with groups C and LE (p = 0.03). The number (%) of patients with unscheduled medical visits also decreased significantly in Group SE compared with Groups C and LE (p = 0.02). We conclude that a structured educational intervention emphasizing self-management improves patient outcomes significantly more than a limited intervention or conventional treatment.


Assuntos
Asma/prevenção & controle , Nebulizadores e Vaporizadores , Planejamento de Assistência ao Paciente , Educação de Pacientes como Assunto/métodos , Participação do Paciente , Autocuidado/métodos , Ensino/métodos , Doença Aguda , Adulto , Análise de Variância , Asma/diagnóstico , Asma/tratamento farmacológico , Asma/psicologia , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Morbidade , Pico do Fluxo Expiratório , Qualidade de Vida , Encaminhamento e Consulta , Autocuidado/psicologia , Resultado do Tratamento
7.
Subst Use Misuse ; 33(3): 555-86, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9533731

RESUMO

This article describes a preliminary study of screening/diagnostic instruments for prediction for large-scale application in the military field at the Neuropsychiatric Department of the Military Hospital of Legal Medicine of Verona and for the prevention of self-destructive behaviors, particularly through the use of drugs. 170 subjects divided into three subsamples were examined. The first subsample was characterized by a strong tendency towards normalcy, the second by a strong tendency towards pathology, and the third by a great variety of expressions of psychological and social problems, which were not necessarily related to drug use. These subjects were administered a questionnaire designed according to Squashing Theory principles (Buscema, 1994a). Answers were processed by an Artificial Neural Network created by Semeion in Rome (Buscema, 1996) and were compared with a standard clinical psychiatric assessment report and with the results of psychodiagnostic tests. Results document ANNs' remarkable ability to recognize subjects with declared, in exordium and "at risk" pathological behaviors. Blind results on learning and trial samples show a very high predictive capacity (over 90%). A comparison with the examined subjects' clinical report and the results of the first follow-up also document very high agreements. The broad variation of answers obtained in the third subsample allows further methodological reflections on the contribution of Artificial Neural Networks and Squashing Theory to the study of deviance, for both sociologists and clinicians, and not only for those in the field of drug addiction.


Assuntos
Inteligência Artificial , Medicina Legal , Dependência de Heroína/diagnóstico , Aplicações da Informática Médica , Militares/psicologia , Redes Neurais de Computação , Adulto , Seguimentos , Dependência de Heroína/epidemiologia , Hospitais Militares , Humanos , Itália/epidemiologia , Masculino , Projetos Piloto , Estudos Prospectivos , Inquéritos e Questionários , Fatores de Tempo
8.
Br J Haematol ; 88(3): 618-20, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7819076

RESUMO

Seven patients with chronic immune thrombocytopenic purpura (ITP) were treated with intramuscular anti-D (anti-D IgG) five times, on an alternate-day basis, or until a platelet count of 100 x 10(9)/l was achieved, and, subsequently, when necessary to maintain platelet counts above 50 x 10(9)/l. Five patients responded to therapy, two of whom entered long-term remission. Although signs of haemolysis were present in all patients, anaemia was never a problem. No patient developed haematomas at the site of injection. We suggest that intramuscular anti-D represents a safe and relatively inexpensive alternative to intravenous gamma globulins (IVGG) for children with severe chronic ITP.


Assuntos
Púrpura Trombocitopênica Idiopática/terapia , Imunoglobulina rho(D)/uso terapêutico , Adolescente , Criança , Doença Crônica , Feminino , Humanos , Injeções Intramusculares , Masculino , Contagem de Plaquetas , Imunoglobulina rho(D)/administração & dosagem
9.
Proc Natl Acad Sci U S A ; 91(15): 7262-6, 1994 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-8041777

RESUMO

We have determined the coding sequences of red and green visual pigment genes of the chimpanzee, gorilla, and orangutan. The deduced amino acid sequences of these pigments are highly homologous to the equivalent human pigments. None of the amino acid differences occurred at sites that were previously shown to influence pigment absorption characteristics. Therefore, we predict the spectra of red and green pigments of the apes to have wavelengths of maximum absorption that differ by < 2 nm from the equivalent human pigments and that color vision in these nonhuman primates will be very similar, if not identical, to that in humans. A total of 14 within-species polymorphisms (6 involving silent substitutions) were observed in the coding sequences of the red and green pigment genes of the great apes. Remarkably, the polymorphisms at 6 of these sites had been observed in human populations, suggesting that they predated the evolution of higher primates. Alleles at polymorphic sites were often shared between the red and green pigment genes. The average synonymous rate of divergence of red from green sequences was approximately 1/10th that estimated for other proteins of higher primates, indicating the involvement of gene conversion in generating these polymorphisms. The high degree of homology and juxtaposition of these two genes on the X chromosome has promoted unequal recombination and/or gene conversion that led to sequence homogenization. However, natural selection operated to maintain the degree of separation in peak absorbance between the red and green pigments that resulted in optimal chromatic discrimination. This represents a unique case of molecular coevolution between two homologous genes that functionally interact at the behavioral level.


Assuntos
Variação Genética , Pigmentos da Retina/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA , Feminino , Gorilla gorilla , Humanos , Masculino , Dados de Sequência Molecular , Pan troglodytes , Polimorfismo Genético , Pongo pygmaeus , Opsinas de Bastonetes/genética , Seleção Genética , Homologia de Sequência de Aminoácidos
10.
Hum Mol Genet ; 2(9): 1413-21, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8242064

RESUMO

We studied polymorphisms in the coding sequences of the human red and green opsin genes of 133 Caucasian males. Eleven polymorphic sites were discovered in the red opsin gene, seven of which were in exon 3, three in exon 4 and one in exon 5. Polymorphisms at 8 of these sites resulted in amino acid substitutions which generated a total of 18 unique red opsins in the population. The substitutions at three (S180A, I230T, and A233S) of the 8 sites involve hydroxyl-bearing to non-polar amino acid residues, and are therefore likely to alter spectral characteristics of the red pigment. Eight polymorphic sites were observed in the green opsin coding sequences, six of which were in exon 3, one in exon 2 and one in exon 5. Five of the eight involved amino acid substitutions which generated 15 unique green opsins in the population. Substitutions at two of these sites involve hydroxyl-bearing vs. non-polar residues. Six polymorphisms, all of which are located in exon 3, are shared between the red and green opsin genes, essentially making it difficult to assign this exon to either of these genes. Markers in exon 3 are in partial linkage disequilibrium with those in exons 4 and 5, whereas the latter two are in strong linkage disequilibrium with each other. Furthermore, markers in the 5' region of exon 3 are also in only partial (54%) disequilibrium with those in the 3' region. The above results strongly suggest a history of frequent gene conversion, mainly localized to exon 3, in the lineages leading to the human red and green opsin genes.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Opsinas de Bastonetes/genética , Sequência de Aminoácidos , Sequência de Bases , Evolução Biológica , Mapeamento Cromossômico , Primers do DNA/genética , Éxons , Variação Genética , Haplótipos , Humanos , Desequilíbrio de Ligação , Masculino , Dados de Sequência Molecular , Polimorfismo Genético
12.
Proc Natl Acad Sci U S A ; 89(20): 9710-4, 1992 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-1409688

RESUMO

The human red and green photopigments are specified by genes on the long arm of the X chromosome (Xq28). In individuals with normal color vision, the locus was proposed to consist of a single red pigment gene upstream of one or more copies of green pigment genes. The presence of a single red pigment gene in the array was confirmed by demonstration of only one retinal mRNA transcript coding for the red opsin. In individuals with multiple green pigment genes, it is unknown whether all genes are expressed. We analyzed the sequence of red- and green-specific mRNA from retinas of individuals with multiple green pigment genes in comparison with the corresponding genomic DNA sequences. The data showed that only a single green pigment gene is expressed. We therefore suggest that a locus control-like element, already known to be located 3.8 kilobases upstream of the transcription initiation site of the red pigment gene, allows transcription of only a single copy of the green pigment genes, probably the most proximal copy. This finding provides an explanation for the not-infrequent presence of 5' green-red hybrid genes in individuals with normal color vision. Such hybrid genes are usually associated with defective color vision. We suggest that 5' green-red hybrid genes produce defective color vision only when their position in the gene array allows expression in the retinal cone cells.


Assuntos
Retina/fisiologia , Opsinas de Bastonetes/genética , Alelos , Sequência de Bases , Expressão Gênica , Humanos , Masculino , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos/química , Reação em Cadeia da Polimerase , Polimorfismo Genético , Transcrição Gênica , Cromossomo X
14.
Proc Natl Acad Sci U S A ; 89(12): 5625-9, 1992 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-1608972

RESUMO

Rhizobium meliloti strain SU47 produces both high molecular weight (HMW) and low molecular weight (LMW) forms of an acidic exopolysaccharide, succinoglycan. Genetic studies have shown that succinoglycan is required for alfalfa root nodule invasion. We found that LMW succinoglycan, when applied exogenously to alfalfa roots, restored nodule invasion to exoA, exoB, exoF, and exoH mutants. Nodule initiation signals were not involved, since LMW succinoglycan from R. meliloti nodD1D2D3 and nodA mutants and from luteolin-induced wild-type cultures elicited effects similar to LMW succinoglycan from the uninduced wild-type strain. In contrast, LMW fractions from an exoA mutant, nonsuccinylated LMW succinoglycan, and HMW succinoglycan did not promote invasion, nor did LMW exopolysaccharides from R. leguminosarum bv. trifolii and Rhizobium sp. strain NGR234. LMW succinoglycan could be separated by anion-exchange chromatography into several distinct subfractions differing in repeating subunit multiplicities (monomer, trimer, and tetramer) and charge. When tested singly, only the most charged, tetrameric form was active. These results show that a specific oligosaccharide form of succinoglycan promotes nodule invasion in alfalfa. The implications for the mode of action of succinoglycan are discussed.


Assuntos
Medicago sativa/microbiologia , Oligossacarídeos/metabolismo , Polissacarídeos Bacterianos/metabolismo , Sinorhizobium meliloti/fisiologia , Cromatografia por Troca Iônica , Genes Bacterianos , Peso Molecular , Mutação , Oligossacarídeos/isolamento & purificação , Polissacarídeos Bacterianos/isolamento & purificação , Sinorhizobium meliloti/genética
15.
J Bacteriol ; 173(10): 3066-77, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-2022612

RESUMO

Rhizobium sp. strain NGR234 produces large amounts of acidic exopolysaccharide. Mutants that fail to synthesize this exopolysaccharide are also unable to nodulate the host plant Leucaena leucocephala. A hybrid strain of Rhizobium sp. strain NGR234 containing exo genes from Rhizobium meliloti was constructed. The background genetics and nod genes of Rhizobium sp. strain NGR234 are retained, but the cluster of genes involved in exopolysaccharide biosynthesis was deleted. These exo genes were replaced with genes required for the synthesis of succinoglycan exopolysaccharide from R. meliloti. As a result of the genetic manipulation, the ability of these hybrids to synthesize exopolysaccharide was restored, but the structure was that of succinoglycan and not that of Rhizobium sp. strain NGR234. The replacement genes were contained on a cosmid which encoded the entire known R. meliloti exo gene cluster, with the exception of exoB. Cosmids containing smaller portions of this exo gene cluster did not restore exopolysaccharide production. The presence of succinoglycan was indicated by staining with the fluorescent dye Calcofluor, proton nuclear magnetic resonance spectroscopy, and monosaccharide analysis. Although an NGR234 exoY mutant containing the R. meliloti exo genes produced multimers of the succinoglycan repeat unit, as does the wild-type R. meliloti, the deletion mutant of Rhizobium sp. strain NGR234 containing the R. meliloti exo genes produced only the monomer. The deletion mutant therefore appeared to lack a function that affects the multiplicity of succinoglycan produced in the Rhizobium sp. strain NGR234 background. Although these hybrid strains produced succinoglycan, they were still able to induce the development of an organized nodule structure on L. leucocephala. The resulting nodules did not fix nitrogen, but they did contain infection threads and bacteroids within plant cells. This clearly demonstrated that a heterologous acidic exopolysaccharide structure was sufficient to enable nodule development to proceed beyond the developmental barrier imposed on mutants of Rhizobium sp. strain NGR234 that are unable to synthesize any acidic exopolysaccharide.


Assuntos
Polissacarídeos Bacterianos/metabolismo , Rhizobium/metabolismo , Sequência de Carboidratos , Clonagem Molecular , Análise Mutacional de DNA , DNA Bacteriano/genética , Genes Bacterianos , Teste de Complementação Genética , Lipopolissacarídeos/química , Dados de Sequência Molecular , Desenvolvimento Vegetal , Plantas/microbiologia , Plantas/ultraestrutura , Rhizobium/genética , Simbiose
16.
J Bacteriol ; 171(1): 104-13, 1989 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2536653

RESUMO

The self-transmissible plasmid pXO12 (112.5 kilobases [kb]), originally isolated from strain 4042A of Bacillus thuringiensis subsp. thuringiensis, codes for production of the insecticidal crystal protein (Cry+). The mechanism of pXO12-mediated plasmid transfer was investigated by monitoring the cotransfer of the tetracycline resistance plasmid pBC16 (4.2 kb) and the Bacillus anthracis toxin and capsule plasmids, pXO1 (168 kb) and pXO2 (85.6 kb), respectively. In matings of B. anthracis donors with B. anthracis and Bacillus cereus recipients, the number of Tcr transcipients ranged from 4.8 x 10(4) to 3.9 x 10(6)/ml (frequencies ranged from 1.6 x 10(-4) to 7.1 x 10(-2), and 0.3 to 0.4% of them simultaneously inherited pXO1 or pXO2. Physical analysis of the transferred plasmids suggested that pBC16 was transferred by the process of donation and that the large B. anthracis plasmids were transferred by the process of conduction. The transfer of pXO1 and pXO2 involved the transposition of Tn4430 from pXO12 onto these plasmids. DNA-DNA hybridization experiments demonstrated that Tn4430 was located on a 16.0-kb AvaI fragment of pXO12. Examination of Tra- and Cry- derivatives of pXO12 showed that this fragment also harbored information involved in crystal formation and was adjacent to a restriction fragment containing DNA sequences carrying information required for conjugal transfer.


Assuntos
Bacillus anthracis/genética , Bacillus thuringiensis/genética , Elementos de DNA Transponíveis , Plasmídeos , Bacillus cereus/genética , Genótipo , Hibridização de Ácido Nucleico , Fatores R , Resistência a Tetraciclina/genética
17.
J Bacteriol ; 169(11): 5263-70, 1987 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3117773

RESUMO

The transfer of plasmids by mating from four Bacillus thuringiensis subspecies to Bacillus anthracis and Bacillus cereus recipients was monitored by selecting transcipients which acquired plasmid pBC16 (Tcr). Transcipients also inherited a specific large plasmid from each B. thuringiensis donor at a high frequency along with a random array of smaller plasmids. The large plasmids (ca. 50 to 120 megadaltons), pXO13, pXO14, pXO15, and pXO16, originating from B. thuringiensis subsp. morrisoni, B. thuringiensis subsp. toumanoffi, B. thuringiensis subsp. alesti, and B. thuringiensis subsp. israelensis, respectively, were demonstrated to be responsible for plasmid mobilization. Transcipients containing any of the above plasmids had donor capability, while B. thuringiensis strains cured of each of them were not fertile, indicating that the plasmids confer conjugation functions. Confirmation that pXO13, pXO14, and pXO16 were self-transmissible was obtained by the isolation of fertile B. anthracis and B. cereus transcipients that contained only pBC16 and one of these plasmids. pXO14 was efficient in mobilizing the toxin and capsule plasmids, pXO1 and pXO2, respectively, from B. anthracis transcipients to plasmid-cured B. anthracis or B. cereus recipients. DNA-DNA hybridization experiments suggested that DNA homology exists among pXO13, pXO14, and the B. thuringiensis subsp. thuringiensis conjugative plasmids pXO11 and pXO12. Matings performed between strains which each contained the same conjugative plasmid demonstrated reduced efficiency of pBC16 transfer. However, in many instances when donor and recipient strains contained different conjugative plasmids, the efficiency of pBC16 transfer appeared to be enhanced.


Assuntos
Bacillus thuringiensis/genética , Plasmídeos , Bacillus anthracis/genética , Bacillus cereus/genética , Cruzamentos Genéticos , Genótipo , Especificidade da Espécie
18.
Infect Immun ; 49(2): 291-7, 1985 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3926644

RESUMO

Virulent and certain avirulent strains of Bacillus anthracis harbor a plasmid, designated pXO2, which is involved in the synthesis of capsules. Two classes of rough, noncapsulated (Cap-) variants were isolated from the capsule-producing (Cap+) Pasteur vaccine strains ATCC 6602 and ATCC 4229. One class was cured of pXO2, and the other class still carried it. Reversion to Cap+ was demonstrable only in rough variants which had retained pXO2. Proof that pXO2 is involved in capsule synthesis came from experiments in which the plasmid was transferred by CP-51-mediated transduction and by a mating system in which plasmid transfer is mediated by a Bacillus thuringiensis fertility plasmid, pXO12. Cells of Bacillus cereus and a previously noncapsulated (pXO2-) strain of B. anthracis produced capsules after the acquisition of pXO2.


Assuntos
Bacillus anthracis/genética , Plasmídeos , Bacillus anthracis/patogenicidade , Bacillus anthracis/fisiologia , Bacillus cereus/genética , Bacillus thuringiensis/genética , Bacteriófagos/genética , Parede Celular/fisiologia , Conjugação Genética , Variação Genética , Genótipo , História Antiga , Especificidade da Espécie , Transdução Genética , Virulência
19.
J Bacteriol ; 162(2): 543-50, 1985 May.
Artigo em Inglês | MEDLINE | ID: mdl-3988702

RESUMO

To facilitate the analysis of genetic determinants carried by large resident plasmids of Bacillus anthracis, a mating system was developed which promotes plasmid transfer among strains of B. anthracis, B. cereus, and B. thuringiensis. Transfer of the selectable tetracycline resistance plasmid pBC16 and other plasmids from B. thuringiensis to B. anthracis and B. cereus recipients occurred during mixed incubation in broth. Two plasmids, pXO11 and pXO12, found in B. thuringiensis were responsible for plasmid mobilization. B. anthracis and B. cereus transcipients inheriting either pXO11 or pXO12 were, in turn, effective donors. Transcipients harboring pXO12 were more efficient donors than those harboring pXO11; transfer frequencies ranged from 10(-4) to 10(-1) and from 10(-8) to 10(-5), respectively. Cell-to-cell contact was necessary for plasmid transfer, and the addition of DNase had no effect. The high frequencies of transfer, along with the fact that cell-free filtrates of donor cultures were ineffective, suggested that transfer was not phage mediated. B. anthracis and B. cereus transcipients which inherited pXO12 also acquired the ability to produce parasporal crystals (Cry+) resembling those produced by B. thuringiensis, indicating that pXO12 carries a gene(s) involved in crystal formation. Transcipients which inherited pXO11 were Cry-. This mating system provides an efficient method for interspecies transfer of a large range of Bacillus plasmids by a conjugation-like process.


Assuntos
Bacillus/genética , Conjugação Genética , Plasmídeos , DNA Bacteriano/genética , Vetores Genéticos , Especificidade da Espécie , Fatores de Tempo
20.
Gastroenterology ; 87(3): 503-12, 1984 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6086440

RESUMO

The mechanism of action of Senokot, a widely used laxative, has not been established. Senokot was given orally to rats 8-14 h before intestinal water and electrolyte transport were studied. Senokot significantly decreased colonic and jejunal water absorption measured in vivo by the single-pass perfusion technique. The Senokot changes were not associated with changes in jejunal or colonic histology or adenylate cyclase activity or colonic cyclic adenosine monophosphate content. Senokot also altered active electrolyte transport in rat descending colon as measured by the Ussing chamber-voltage clamp technique. These changes consisted of an increase in short-circuit current and a decrease in active Na and Cl transport that was due to a decrease in the mucosal-to-serosal fluxes. The changes in active electrolyte transport were dependent on Ca++ in the serosal but not the mucosal bathing solution. In contrast, addition of 10(-4) M verapamil to the serosal surface did not alter the Senokot effect. In spite of a dependence on serosal Ca++, Senokot did not alter 45Ca++ entry across the colonic serosal surface. The phospholipase A2 inhibitor quinacrine (10(-4) M) also did not alter the effect of Senokot on colonic Na and Cl transport. Senokot alters active colonic Na and Cl transport via a presently unknown mechanism that is dependent on serosal Ca++.


Assuntos
Cálcio/metabolismo , Colo/metabolismo , Mucosa Intestinal/metabolismo , Jejuno/metabolismo , Extrato de Senna/farmacologia , Adenilil Ciclases/metabolismo , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Cloretos/metabolismo , Colo/efeitos dos fármacos , Colo/enzimologia , AMP Cíclico/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/enzimologia , Jejuno/efeitos dos fármacos , Jejuno/enzimologia , Masculino , Quinacrina/farmacologia , Ratos , Ratos Endogâmicos , Sódio/metabolismo , Verapamil/farmacologia
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