RESUMO
The giant otter, Pteronura brasiliensis, occupies a range including the major drainage basins of South America, yet the degree of structure that exists within and among populations inhabiting these drainages is unknown. We sequenced portions of the mitochondrial DNA (mtDNA) cytochrome b (612bp) and control region (383 bp) genes in order to determine patterns of genetic variation within the species. We found high levels of mtDNA haplotype diversity (h = 0.93 overall) and support for subdivision into four distinct groups of populations, representing important centers of genetic diversity and useful units for prioritizing conservation within the giant otter. We tested these results against the predictions of three hypotheses of Amazonian diversification (Pleistocene Refugia, Paleogeography, and Hydrogeology). While the phylogeographic pattern conformed to the predictions of the Refugia Hypothesis, molecular dating using a relaxed clock revealed the phylogroups diverged from one another between 1.69 and 0.84 Ma, ruling out the influence of Late Pleistocene glacial refugia. However, the role of Plio-Pleistocene climate change could not be rejected. While the molecular dating also makes the influence of geological arches according to the Paleogeography Hypothesis extremely unlikely, the recent Pliocene formation of the Fitzcarrald Arch and its effect of subsequently altering drainage pattern could not be rejected. The data presented here support the interactions of both climatic and hydrological changes resulting from geological activity in the Plio-Pleistocene, in shaping the phylogeographic structure of the giant otter.
Assuntos
Sequência Conservada/genética , Evolução Molecular , Lontras/genética , Animais , Teorema de Bayes , Citocromos b/genética , DNA Mitocondrial/genética , Demografia , Drenagem Sanitária , Variação Genética , Haplótipos/genética , Funções Verossimilhança , Dados de Sequência Molecular , Nucleotídeos/genética , Lontras/crescimento & desenvolvimento , Filogeografia , América do Sul , Fatores de TempoRESUMO
A bacterium that grows and expresses plant growth promotion traits at 4 degrees C was isolated from the rhizospheric soil of Amaranth, cultivated at a high altitude location in the North Western Indian Himalayas. The isolate was Gram negative and the cells appeared as rods (2.91 x 0.71 microm in size). It grew at temperatures ranging from 4 to 30 degrees C, with a growth optimum at 28 degrees C. It exhibited tolerance to a wide pH range (5-10; optimum 8.0) and salt concentrations up to 6% (wt/vol). Although it was sensitive to Rifampicin (R 20 microg mi-1), Gentamicin (G 3 microg mi-1), and Streptomycin (S 5 microg mi-1), it showed resistance to higher concentrations of Ampicillin (A 500 microg mi-1), Penicillin (P 300 microg mi-1), Polymixin B sulphate (Pb 100 microg mi-1) and Chloramphenicol (C 200 microg mi-1). The 16S rRNA sequence analysis revealed maximum identity with Pseudomonas lurida. The bacterium produced indole Acetic Acid (IAA) and solubilizes phosphate at 4, 15 and 28 degrees C. It also retained its ability to produce rhamnolipids and siderophores at 15 degrees C. Seed bacterization with the isolate enhanced the germination, shoot and root lengths of thirty-day-old wheat seedlings by 19.2, 30.0 & 22.9% respectively, as compared to the un-inoculated controls.
Assuntos
Amaranthus/microbiologia , Temperatura Baixa , Pseudomonas/metabolismo , Microbiologia do Solo , Amaranthus/crescimento & desenvolvimento , Índia , Filogenia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/microbiologia , Pseudomonas/genética , Pseudomonas/crescimento & desenvolvimento , RNA Ribossômico 16S/genéticaRESUMO
A bacterium that grows and expresses plant growth promotion traits at 4°C was isolated from the rhizospheric soil of Amaranth, cultivated at a high altitude location in the North Western Indian Himalayas. The isolate was Gram negative and the cells appeared as rods (2.91 x 0.71 μm in size). It grew at temperatures ranging from 4 to 30°C, with a growth optimum at 28°C. It exhibited tolerance to a wide pH range (5-10; optimum 8.0) and salt concentrations up to 6 percent (wt/vol). Although it was sensitive to Rifampicin (R 20 μg mi-1), Gentamicin (G 3 μg mi-1), and Streptomycin (S 5 μg mi-1), it showed resistance to higher concentrations of Ampicillin (A 500 μg mi-1), Penicillin (P 300 μg mi-1), Polymixin B sulphate (Pb 100 μg mi-1) and Chloramphenicol (C 200 μg mi-1). The 16S rRNA sequence analysis revealed maximum identity with Pseudomonas lurida. The bacterium produced indole Acetic Acid (IAA) and solubilizes phosphate at 4, 15 and 28°C. It also retained its ability to produce rhamnolipids and siderophores at 15°C. Seed bacterization with the isolate enhanced the germination, shoot and root lengths of thirty-day-old wheat seedlings by 19.2, 30.0 & 22.9 percent respectively, as compared to the un-inoculated controls.
Assuntos
Amaranthus/microbiologia , Temperatura Baixa , Pseudomonas/metabolismo , Microbiologia do Solo , Amaranthus/crescimento & desenvolvimento , Índia , Filogenia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/microbiologia , Pseudomonas/genética , Pseudomonas/crescimento & desenvolvimento , /genéticaRESUMO
A 46-year-old female is described with prolonged, progressive dementia and a brain biopsy consistent with Creutzfeldt-Jakob disease (CJD). She had neither myoclonic jerks nor an electroencephalogram with periodic spikes and suppression. Five of her close relatives were also demented. The nosology of CJD was discussed in the light of this case in which histopathology was characteristic of spongiform encephalopathy but the clinical features were atypical. We concluded that it would be premature to expand the traditional diagnostic criteria to include such cases as having CJD but, at the same time, it would be prudent to handle tissue, linens and surgical instruments as if they were contaminated by the resistant agent of CJD.
Assuntos
Síndrome de Creutzfeldt-Jakob/diagnóstico , Demência/diagnóstico , Biópsia , Encéfalo/patologia , Encéfalo/ultraestrutura , Síndrome de Creutzfeldt-Jakob/genética , Síndrome de Creutzfeldt-Jakob/patologia , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , LinhagemRESUMO
A comparative study with 2 tier and 3 tier combination of Rifampicin, Clofazimine, DDS, INAH and Thiacetazone was conducted on fifty lepromatous leprosy cases for varying periods. Assessment showed that 2 tier combination of clofazimine and DDS produced good results but the cost stood in the way; whereas 3 tier combination of DDS, thiacetazone and INAH also yielded good results with much less expenses to be incurred by the patients. Whether therapy with this 3 tier combination could be continued for a longer period with sustained improvement is yet to be assessed by further studies for a considerable period.
Assuntos
Masculino , Feminino , Humanos , Criança , Adulto , Pessoa de Meia-Idade , Adolescente , Clofazimina/uso terapêutico , Dapsona/uso terapêutico , Hanseníase/tratamento farmacológico , Isoniazida/uso terapêutico , Quimioterapia Combinada , Rifampina/uso terapêutico , Tioacetazona/uso terapêuticoRESUMO
Out of 265 contacts of bacillary positive lepromatous leprosy patients 92 were lepromin positive...
Assuntos
Masculino , Feminino , Humanos , Pré-Escolar , Criança , Adulto , Adolescente , Antígeno de Mitsuda/imunologia , Hanseníase/imunologiaRESUMO
1 An attempt has been made to transmit the human leprosy bacillus to white rats by injecting the exposed sciatic nerve with a suspension of bacillus-rich leprous tissue mixed with an equal amount of sterile egg albumen. 2- One of the five rats so inoculated showed evidence of massive infection with an acid-fast organism whem sacrified three and one-half months after inoculation. In an attempt to ascertain the actual nature of this acid-fast organism, material from this rat was passed by intraperitoneal inoculation to other rats and to guinea-pigs; and a second similar passage has been made, too recently for the results to be known, to rats and mice from lesions which developed in one of the first-passage rats. 3- Negative results of cultures and of the guinea-pig inoculations indicate that the acid-fast bacillus encountered is not the tubercle bacillus or any other readily-cultivated mycobacterium. The occurrence of an infection by acid-fast bacilli in the rat of the first passage group which survived sufficiently long suggest that the bacillus may be the Stefansky bacillus and not the human leprosy bacillus. 4- This observation brings out the great importance of excluding chance infection with Stefansky bacillus of rodents inoculated experimentally with human leprosy material, especially in laboratories where work with both human and rat leprosy is being carried out.