RESUMO
The aim of this study was to objectively measure demand for critical care services in a southern African tertiary referral centre. We carried out a point prevalence study of medical and surgical admissions over a 48-h period at the University Teaching Hospital, Lusaka, recording the following: age; sex; diagnosis; Human Immunodeficiency Virus (HIV) status and National Early Warning Score. One-hundred and twenty medical and surgical admissions were studied. Fifty-four patients (45%) had objective evidence of a requirement for critical care review and potential or probable admission to an intensive care unit, according to the Royal College of Physicians (UK) guidelines. A greater than expected HIV rate was also noted; 53 of 75 tested patients (71%). When applied to the estimated 17,496 annual acute admissions, this would equate to 7873 patients requiring critical care input annually at this hospital alone. In contrast to this demand, we identified 109 critical care beds nationally, and only eight at this institution.
Assuntos
Cuidados Críticos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Hospitais de Ensino , Humanos , Pacientes Internados , Masculino , Pessoa de Meia-Idade , Morbidade , Admissão do Paciente , Adulto Jovem , ZâmbiaRESUMO
Subclinical necrotic enteritis (NE) was induced in broiler chicks using a high dose of Eimeria spp. vaccine in the drinking water on day 9, and Clostridium perfringens (Cp) culture mixed in the feed on days 14 and 15. The aim was to evaluate the effects of probiotic Bacillus amyloliquefaciens strain H57 (H57) in preventing NE in chicks. Day-old Ross 308, male broilers were weighed and randomly assigned to 6 treatment groups (6 replicate cages/treatment and 8 birds/cage). Birds in group 1 (control) were fed the basal wheat-soybean diet without H57 or NE infection; in group 2 (Eimeria) were treated with Eimeria alone; in group 3 (Cp) were treated with Cp alone; in group 4 (NE) received both Eimeria and Cp; in group 5 (NE-H57) received NE infection and H57; and group 6 (H57) received H57. The basal diet of chicks in groups 5 and 6 was supplemented with H57 at a density of 2 × 108 spores/g feed from 1 D of age. On day 21, there were no significant treatment effects on BW and feed intake between control and H57 birds. However, on day 21, the feed conversion ratio of NE-H57 birds was significantly improved when compared with NE birds (1.28 vs. 1.36; P < 0.001). Birds challenged with NE had a higher occurrence of pasty vent than birds infected with either Eimeria, Cp, or NE-H57 (41 vs. 27 vs. 29 vs. 19%, respectively; P < 0.001). Intestinal lesion scores of NE birds were also higher than those of Eimeria, Cp, and NE-H57 birds (5.67 vs. 2.56 vs. 2.78 vs. 2.10, respectively; P < 0.001) and correlated with pasty vent (Pearson's r = 0.56; P < 0.001). Microscopic evaluation showed mucosal damage and necrosis in NE birds. In contrast, villi from NE-H57 birds were normal, with no damage or infiltration with Eimeria or Cp. H57 appears to be effective in challenged birds, as it maintained epithelial barrier integrity and improved feed efficiency.
Assuntos
Bacillus amyloliquefaciens , Galinhas , Infecções por Clostridium , Coccidiose , Enterite , Doenças das Aves Domésticas , Probióticos , Animais , Bacillus amyloliquefaciens/imunologia , Infecções por Clostridium/microbiologia , Infecções por Clostridium/prevenção & controle , Infecções por Clostridium/veterinária , Clostridium perfringens , Coccidiose/microbiologia , Coccidiose/prevenção & controle , Coccidiose/veterinária , Enterite/microbiologia , Enterite/prevenção & controle , Enterite/veterinária , Masculino , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controleRESUMO
Nodulation by the Rhizobium strain IC3342 causes a leaf curl syndrome in certain tropical legumes such as pigeon pea (Cajanus cajan) (N.M. Upadhyaya, J.V.D.K. Kumar Rao, D.S. Letham, and P.J. Dart, Physiological and Molecular Plant Pathology 39:357-373, 1991). Transposon (Tn5) mutagenesis of this leaf curl-inducing (Curl+) Rhizobium strain yielded two Curl- Fix- and three Curl- Fix+ mutants. Plasmid visualization and subsequent Southern blot hybridization analyses with Tn5, nif and nod gene probes showed that the Tn5 element had inserted into the symbiotic (Sym) plasmid in three of the mutants. Restriction endonuclease analyses indicated that none of the Tn5 insertions were closely linked. Tn5-containing EcoRI fragments were cloned from each mutant and used as probes to isolate the corresponding wild-type DNA fragments from a cosmid (pLAFR3) genomic library. Fix+ and/or Curl+ phenotypes were restored in each mutant by the introduction of cosmids containing the corresponding wild-type DNA. A closely related but Curl- Rhizobium strain ANU240 was shown, by Southern hybridization, to contain conserved DNA sequences of all but one of the identified genetic regions of the Curl+ Rhizobium strain IC3342. Cosmids containing the genetic region unique to the strain IC3342, designated lcr1, conferred a Curl+ phenotype on the strain ANU240. DNA sequence analysis of the cloned lcr1 region revealed five open reading frames (ORFs). The ORF2 showed homology with the Escherichia coli regulatory gene ompR, and ORF4 showed homology with E. coli and Rhizobium meliloti regulatory genes fnr and fixK, respectively.
Assuntos
Fabaceae/microbiologia , Regulação Bacteriana da Expressão Gênica , Plantas Medicinais , Rhizobium/genética , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Sequência de Bases , Southern Blotting , Clonagem Molecular , Cosmídeos , Elementos de DNA Transponíveis , DNA Bacteriano/genética , Escherichia coli/genética , Fabaceae/citologia , Fabaceae/genética , Genes Bacterianos , Genes Reguladores , Teste de Complementação Genética , Dados de Sequência Molecular , Mutagênese Insercional , Fases de Leitura Aberta , Fenótipo , Mapeamento por Restrição , Homologia de Sequência do Ácido NucleicoRESUMO
Dart, P. J. (University of Sydney, Sydney, Australia), and F. V. Mercer. Fine structure of bacteroids in root nodules of Vigna sinensis, Acacia longifolia, Viminaria juncea, and Lupinus angustifolius. J. Bacteriol. 91:1314-1319.-In nodules of Vigna sinensis, Acacia longifolia, and Viminaria juncea, membrane envelopes enclose groups of bacteroids. The bacteroids often contain inclusion granules and electron-dense bodies, expand little during development, and retain their rod form with a compact, central nucleoid area. The membrane envelope may persist around bacteroids after host cytoplasm breakdown. In nodules of Lupinus angustifolius, the membrane envelopes enclose only one or two bacteroids, which expand noticeably during development and change from their initial rod structure.
Assuntos
Acacia , Bacteroides/citologia , Magnoliopsida , Membrana Celular , Núcleo Celular , Grânulos Citoplasmáticos , Técnicas In Vitro , Microscopia EletrônicaRESUMO
1. Leghaemoglobins from soya-bean (Glycine max) and cowpea (Vigna unguiculata) root nodules were purified by chromatography on DEAE-cellulose phosphate columns at pH8.0 and pH5.8, to avoid the relatively low pH (5.2) commonly used to purify these proteins. 2. E.p.r. (electron-paramagnetic-resonance) spectra of the fluoride, azide, hydroxide and cyanide complexes of these ferric leghaemoglobins were very similar to the spectra of the corresponding myoglobin derivatives, indicating that the immediate environment of the iron in leghaemoglobin and myoglobin is similar, an imidazole moiety of histidine being the proximal ligand to the haem iron [cf. Appleby, Blumberg, Peisach, Wittenberg & Wittenberg (1976) J. Biol. Chem.251, 6090-6096]. 3. E.p.r. spectra of the acid-metleghaemoglobins showed prominent high-spin features very near g=6 and g=2 and, unlike myoglobin, small low-spin absorptions near g=2.26, 2.72 and 3.14. The width of the g=6 absorption derivative at 10-20K was about 4-4.5mT, similar to the value for acid-methaemoglobin. In contrast, a recently published (Appleby et al., 1976) spectrum of acid-metleghaemoglobin a had less high-spin character and a much broader absorption derivative around g=6. 4. E.p.r. spectra of ferric leghaemoglobin nicotinate and imidazole complexes suggest that the low-spin absorption near g=3.14 can be attributed to a trace of ferric leghaemoglobin nicotinate, and those near g=2.26 and 2.72 are from an endogenous dihistidyl haemichrome. 5. A large e.p.r. signal at g=2 in all samples of crude leghaemoglobin was shown to be from nitrosyl-leghaemoglobin. A soya-bean sample contained 27+/-3% of the latter. A previously unidentified form of soya-bean ferrous leghaemoglobin a was shown to be its nitrosyl derivative. If this is not an artifact, and occurs in the root nodule, the nitrosyl radical may interfere with the function of leghaemoglobin.
Assuntos
Hemeproteínas/análise , Leghemoglobina/análise , Cromatografia DEAE-Celulose , Espectroscopia de Ressonância de Spin Eletrônica , Fabaceae , Compostos Férricos , Compostos Ferrosos , Concentração de Íons de Hidrogênio , Leghemoglobina/isolamento & purificação , Plantas Medicinais , Glycine maxRESUMO
A modified gel electrophoresis technique provided a reproducible way of detecting and isolating plasmids with molecular weights ranging from 12 X 10(6) to 370 X 10(6) for Azospirillum species. Analysis with the nifHD region of Rhizobium trifolii showed that the Azospirillum nif genes were chromosomally located in all eight strains investigated and not on endogenous plasmids.
Assuntos
Bactérias/genética , Cromossomos Bacterianos/fisiologia , Genes Bacterianos , Fixação de Nitrogênio , Plasmídeos , Bactérias/metabolismo , Mapeamento Cromossômico , Enzimas de Restrição do DNA , Desoxirribonuclease EcoRI , Hibridização de Ácido Nucleico , Rhizobium/genéticaRESUMO
Two Rhizobium strains were cultured on a defined medium; one was a normal strain of the cowpea group (ANU240) while the other (IC3342) was an unusual but related strain of the same group which induced abnormal shoot development, including proliferation of lateral buds, in nodulated plants. Culture supernatants were examined for the presence of cytokinins by mass spectrometry using deuterium-labelled internal standards and by radioimmunoassay. In culture supernatants of both strains a range of cytokinins was detected and quantified, but N6-(2-isopentenyl)adenine (iP) and zeatin (Z) were the dominant cytokinins. The levels of Z and iP in supernatants of strain IC3342 were 26 and 8 times, respectively, those in supernatants of the strain ANU240. These results appear to provide the first unambiguous identifications of cytokinins in Rhizobium culture media. The cytokinin level in xylem sap of pigeonpea plants inoculated with strain IC3342 was markedly greater than that in plants inoculated with a normal nodulating strain. The abnormal proliferation of lateral buds in the former plants is probably linked to the elevation of cytokinin level in xylem sap caused by strain IC3342.
Assuntos
Citocininas/biossíntese , Rhizobium/metabolismo , Adenina/análogos & derivados , Adenina/biossíntese , Adenina/química , Citocininas/química , Cromatografia Gasosa-Espectrometria de Massas , Isopenteniladenosina , Estrutura Molecular , Zeatina/análogos & derivados , Zeatina/química , Zeatina/metabolismoRESUMO
A uniquely abnormal shoot development (shoot tip-bending, leaf curling, release from apical dominance, and stunted growth) in pigeonpea (Cajanus cajan Millsp) induced by a nodulating Rhizobium strain, IC3342, is thought to be due to a hormonal imbalance. Amaranthus betacyanin bioassay indicated that xylem exudate and leaf extracts from pigeonpea plants with Rhizobium-induced leaf curl symptoms contained high concentrations of cytokinin relative to those in normal plants. Radioimmunoassay (RIA) of samples purified with high performance liquid chromatography revealed that zeatin riboside (ZR) and dihydrozeatin riboside (DZR) concentrations in xylem sap from plants with leaf curl symptoms were 7 to 9 times higher than those in the sap from symptomless, nodulated plants. The sap from symptomless plants nodulated by a Curl(-) mutant had ZR and DZR concentrations comparable to those in the normal plant sap. RIA indicated that the respective concentrations of zeatin and N(6)-isopenteny-ladenine in culture filtrates of the curl-inducing strain IC3342 were 26 and 8 times higher than those in filtrates of a related normal nodulating strain (ANU240). Gas chromatographic-mass spectrometric analyses revealed similar differences. Gene-specific hybridization and sequence comparisons failed to detect any homology of IC3342 DNA to Agrobacterium tumefaciens or Pseudomonas savastanoi genetic loci encoding enzymes involved in cytokinin biosynthesis.