RESUMO
High-velocity galactic outflows, driven by intense bursts of star formation and black hole accretion, are processes invoked by current theories of galaxy formation to terminate star formation in the most massive galaxies and to deposit heavy elements in the intergalactic medium. From existing observational evidence (for high-redshift galaxies) it is unclear whether such outflows are localized to regions of intense star formation just a few kiloparsecs in extent, or whether they instead have a significant impact on the entire galaxy and its surroundings. Here we present two-dimensional spectroscopy of a star-forming galaxy at redshift z = 3.09 (seen 11.5 gigayears ago, when the Universe was 20 per cent of its current age): its spatially extended Lyalpha line emission appears to be absorbed by H i in a foreground screen covering the entire galaxy, with a lateral extent of at least 100 kpc and remarkable velocity coherence. This screen was ejected from the galaxy during a starburst several 10(8) years earlier and has subsequently swept up gas from the surrounding intergalactic medium and cooled. This demonstrates the galaxy-wide impact of high-redshift superwinds.
RESUMO
A diffusible factor produced and secreted by malignant murine cells was capable of inducing plasminogen activator production by normal diploid human fibroblasts. The factor's ability to induce plasminogen activator was insensitive to treatment with nucleases, but its activity was destroyed by digestion with proteases. It is proposed that such a factor would play a role in malignancy if it would recruit normal cells that were adjacent to transformed cells to produce plasminogen activator which could result in tumor-promoted proteolysis.
Assuntos
Neoplasias Experimentais/metabolismo , Peptídeos/metabolismo , Ativadores de Plasminogênio/biossíntese , Animais , Cricetinae , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Células Híbridas/metabolismo , Melanoma/metabolismo , Camundongos , Peptídeos/farmacologia , RatosRESUMO
The method of extraction of outer membrane proteins (OMPs), the conditions of electrophoretic transfer, and the conditions of antibody binding, were compared in Western blotting studies of Neisseria meningitidis outer membrane antigens. The OMP profiles obtained by SDS-PAGE of outer membrane vesicles extracted with lithium chloride/sodium acetate were compared with profiles obtained by Sarkosyl extraction; these profiles were further compared with the patterns obtained by 125I-labelling of surface-exposed proteins. Sarkosyl extracts gave profiles most closely resembling those of 125I-labelled whole-cells and gave the best resolution of the major proteins. After transfer in Tris-glycine-methanol buffer some proteins, including the major proteins, were not completely transferred and remained in the gel, with the class 2/3 and 5 proteins not effectively detected on nitrocellulose by amido black staining. There was weak antibody recognition of the class 1 and 4 proteins but good recognition of lipooligosaccharide (LOS) and H8 antigen. Empigen BB had no effect on renaturation of the class 1 protein. When 0.1% SDS was incorporated in the same buffer all of the proteins were removed from the gel, and although the major proteins bound to nitrocellulose other proteins did not. There was weak antibody recognition of the class 1 and 4 proteins, stronger reaction to the class 5 protein, but no recognition of the class 2 protein, LOS or H8 antigen, Empigen BB slightly enhanced antibody recognition of the class 1 protein. After transfer in Tris-glycine buffer, all the major proteins were transferred and bound to nitrocellulose and, other than the class 2 protein, were recognised by antibody, both in the presence or absence of Empigen BB, as were LOS and the H8 antigen. Differences existed in the patterns of antibody recognition between the lithium and the Sarkosyl extracts; additional proteins were recognised in the lithium extracts. The surface-labelling studies indicated, however, that some of these proteins were not surface-exposed. Some minor proteins appeared to be more highly immunogenic than the major proteins.
Assuntos
Antígenos de Bactérias/análise , Proteínas da Membrana Bacteriana Externa/análise , Infecções Meningocócicas/imunologia , Neisseria meningitidis/imunologia , Acetatos , Ácido Acético , Anticorpos Antibacterianos/análise , Antígenos de Bactérias/isolamento & purificação , Antígenos de Superfície/análise , Proteínas da Membrana Bacteriana Externa/isolamento & purificação , Western Blotting , Soluções Tampão , Cloretos , Detergentes , Humanos , Radioisótopos do Iodo , Lítio , Cloreto de Lítio , Compostos Orgânicos , Conformação Proteica , Sarcosina/análogos & derivadosRESUMO
The optimal conditions for the detection of outer membrane proteins (OMPs) and lipopolysaccharide (LPS) of Pasteurella haemolytica by immunoblotting were evaluated. The variables examined included the equilibration time of the gels before transfer, composition of the transfer buffer, type of blotting membrane, blocking agent, effect of the zwitterionic detergent Empigen BB on protein renaturation, and the development reagent. The composition of the transfer buffer and time of gel equilibration significantly affected the efficiency of transfer of both OMPs and LPS. However, the optimal conditions for the transfer of OMPs were not the same as those for LPS. Thus, optimal transfer of OMPs occurred in Tris-glycine buffer, with prior equilibration of the gels to allow for expansion, whereas optimal transfer of LPS was achieved in Tris-glycine-methanol buffer with no equilibration of the gels. In Tris-glycine-methanol buffer, gel equilibration resulted in a significantly reduced transfer of both OMPs and LPS, probably due to the removal of SDS from these components. The use of Zeta-Probe blotting membrane which, unlike nitrocellulose, does not require methanol for optimal protein binding, did not result in improved binding of OMPs or LPS in the absence of methanol and, even after prolonged blocking (> 2 h), gave higher background staining than did nitrocellulose. Effective blocking of nitrocellulose was achieved with 3% (w/v) gelatin, 2.5% (w/v) skimmed milk or 0.3% (v/v) Tween 20, whereas increased background staining occurred with 1% (w/v) bovine serum albumin or 1% (w/v) ovalbumin. The incorporation of Empigen BB in the primary antibody buffer did not improve antibody recognition of proteins as a result of their renaturation. For the horseradish-peroxidase enzyme development system, the substrate 3,3'-diaminobenzidine tetrahydrochloride was more sensitive, and developed more quickly, than 4-chloro-1-naphthol, but faded more rapidly after drying of the membrane. 4-chloro-1-naphthol was more suitable for identifying OMPs because less background staining occurred, whereas 3,3'-diaminobenzidine tetrahydrochloride was more suitable for the detection of LPS due to its greater sensitivity.
Assuntos
Proteínas da Membrana Bacteriana Externa/análise , Immunoblotting/métodos , Lipopolissacarídeos/análise , Mannheimia haemolytica/química , Eletroforese em Gel de Poliacrilamida , Estudos de Avaliação como Assunto , Coloração e RotulagemRESUMO
1. Microradiographic techniques have been used to show that endothelium-derived relaxing factor (EDRF), which is believed to be nitric oxide, influences vasomotor responses in small arteries and arterioles down to 25 micron in diameter in an isolated, intact, buffer-perfused ear preparation of the rabbit. Arteries down to 75 micron in diameter, i.e. the central ear artery (G0) and its first three generations of branch vessels (G1, G2 and G3) were studied quantitatively. 2. Relative constrictor responses to 1 micron 5-hydroxytryptamine (5-HT) and the combination of 1 microM 5-HT and 1 microM histamine diminished progressively from G0 to G3. Constrictor responses to 5-HT were doubled in all generations by 1 microM haemoglobin which abolishes EDRF activity. 3. Relative dilator responses to acetylcholine or to substance P in preconstricted arteries were, in contrast, equal in the different generations. Mean -log (IC50) values calculated from diameter measurements were 7.63 +/- 0.10 M and 9.80 +/- 0.11 M, respectively. These dilator responses were abolished by 1 microM haemoglobin, implying that they were EDRF-mediated. Spatial homogeneity of relative dilator responses was found also with glyceryl trinitrate (10 or 50 microM) whose activity is thought to depend on biotransformation to nitric oxide, in both the presence and the absence of haemoglobin. 4. This finding of spatial homogeneity of the diameter response to changes in EDRF activity (or to glyceryl trinitrate) implies that EDRF influences hydrodynamic resistance more in vessels where constrictor tone is high.
Assuntos
Produtos Biológicos/farmacologia , Vasodilatadores/farmacologia , Acetilcolina/farmacologia , Angiografia , Animais , Resistência a Medicamentos , Orelha/irrigação sanguínea , Técnicas In Vitro , Masculino , Contração Muscular/efeitos dos fármacos , Relaxamento Muscular/efeitos dos fármacos , Óxido Nítrico , Coelhos , Serotonina/farmacologia , Substância P/farmacologiaRESUMO
The optimal conditions for the analysis of the lipopolysaccharide (LPS) of two serotype A1 isolates and a serotype A2 isolate of Pasteurella haemolytica by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining were determined. The LPS of the A1 isolates possessed O side chains, consisting of high molecular mass bands with the appearance of a ladder-like pattern, as well as a low molecular mass core-oligosaccharide region; the LPS of the A2 isolate consisted only of the core-oligosaccharide region. Furthermore, the LPS of the two A1 isolates differed in the core-oligosaccharide region. Optimal resolution of low molecular mass LPS components was obtained in a 15% acrylamide resolving gel containing 4 M urea whereas optimal resolution of high molecular mass components was obtained when urea was omitted. Conventional silver staining resulted in excellent visualisation of LPS bands, whereas a modified staining method did not detect additional bands, as has been demonstrated with the LPS of Pseudomonas aeruginosa. Proteinase K digestion of outer membranes gave more clearly defined LPS profiles than did similar digestions of whole cells, and more closely resembled the profiles of purified LPS. With the exception of slight variation in the average molecular mass of a group of O side chains between logarithmic and stationary phases there were no differences in LPS profiles at various stages of the growth cycle; freezing and thawing of LPS samples had no effect on the profiles.
Assuntos
Lipopolissacarídeos/análise , Mannheimia haemolytica/química , Animais , Variação Antigênica , Bovinos , Eletroforese em Gel de Poliacrilamida , Lipopolissacarídeos/química , Lipopolissacarídeos/imunologia , Mannheimia haemolytica/classificação , Mannheimia haemolytica/crescimento & desenvolvimento , Sorotipagem , Coloração pela Prata , Dodecilsulfato de SódioRESUMO
The accumulation of 99mTc-technetium-labelled liposomes in abscesses was studied. Abscesses were produced in the thighs of albino rats by intramuscular injection of Staphylococcus aureus. After 4 days these abscesses were used to determine the localisation of 99mTc-technetium-labelled anionic, cationic and neutral liposomes in the abscess area. This was achieved by radionuclide images produced by a gamma camera and an associated data-processing system. There was a pronounced uptake of 99mTc-technetium-labelled anionic liposomes in the abscess area compared with the corresponding unaffected thigh. Similar uptake was not shown by the 99mTc-technetium-labelled cationic and neutral liposomes. Abscess uptake of anionic liposomes was maximal at or before 30 min after injection and was not enhanced by prior opsonisation with aggregated rat immunoglobulin.
Assuntos
Abscesso/diagnóstico por imagem , Lipossomos , Infecções Estafilocócicas/diagnóstico por imagem , Animais , Computadores , Imunoglobulinas , Proteínas Opsonizantes , Cintilografia , Ratos , TecnécioRESUMO
Using improved methods, we have developed a microangiographic technique for studying the coronary circulation in Langendorff perfused guinea pig, rabbit and ferret hearts. Striking anatomical differences were observed between these species. In the guinea pig, the interventricular septum was supplied by a large septal artery which always arose from the right coronary artery, whereas in the rabbit and ferret, the septal artery was smaller and originated from the left coronary artery. The circumflex artery was more prominent than the right coronary artery in the ferret and guinea pig, whereas the reverse pertained in the rabbit. Extensive apical collateral connections were observed between terminal branches of the left anterior descending, left ventricular branches and the septal artery in the guinea pig, while collaterals were usually absent in the rabbit and ferret. These species differences in the myocardial blood supply have wide ranging implications regarding the choice of small animals for cardiac research.
Assuntos
Angiografia Coronária , Circulação Coronária , Angiografia/métodos , Animais , Vasos Coronários/anatomia & histologia , Vasos Coronários/fisiologia , Feminino , Furões , Cobaias , Masculino , Coelhos , Especificidade da EspécieRESUMO
Yersinia ruckeri is the aetiological agent of enteric redmouth disease (ERM), an acute to chronic bacteraemic infection of salmonid fish. The O-serotypes of 127 isolates of Y. ruckeri obtained from Europe (96 isolates), North America (23 isolates), Australia (six isolates) and South Africa (two isolates), as well as four reference strains, were determined by slide agglutination test and microplate agglutination assay. A serotyping scheme is proposed based on heat-stable O-antigens; the serotypes were designated O1, O2, O5, O6 and O7. The proposed scheme is compared to serotyping schemes described by other authors. All five O-serotypes were present in both Europe and North America, whereas only serotype O1 isolates were identified in Australia and South Africa. These findings suggest that European and North American populations of Y. ruckeri are interrelated, thus supporting previous evidence which suggests that the organism was introduced into Europe from North America by the importation of asymptomatic infected carrier fish. Conversely, the results suggest that Australia and South Africa are more isolated from the dissemination of Y. ruckeri. Serotypes O5, O6 and O7 have not previously been recognized in Europe and these findings will have important implications on the diagnosis of ERM and on the vaccination of fish against this disease. It is suggested that the Australian isolate previously described as serotype III is a rough-type mutant and that other isolates described in the literature as serotype III have been incorrectly serotyped and are, in fact, serotype O1. To avoid further confusion it is suggested that the scheme described here be adopted for serological studies of Y. ruckeri.
Assuntos
Doenças dos Peixes/microbiologia , Salmonidae , Yersiniose/veterinária , Yersinia/classificação , Testes de Aglutinação , Animais , Antígenos de Bactérias/imunologia , Soros Imunes/imunologia , Antígenos O , Sorotipagem , Yersinia/imunologia , Yersiniose/microbiologiaRESUMO
The virulence in rainbow trout (Oncorhynchus mykiss) of 32 isolates of Yersinia ruckeri, representing a range of biotypes, serotypes, and OMP-types, was examined. Virulence was assayed in fish of average weight 7.7 g by bath challenge for 1 h with approximately 5 x 10(7) cells per ml. Two of the six serotype O1 clonal groups of Y. ruckeri, clones 2 and 5, were virulent, whereas the other four clonal groups, clones 1, 3, 4 and 6, as well as all serotype O2, O5, O6 and O7 isolates examined, were avirulent. Analysis of susceptibility to the bactericidal effect of non-immune rainbow trout serum demonstrated an association between virulence and serum resistance. The virulent serotype O1 clonal groups were serum resistant, whereas the avirulent serotype O1 clonal groups and other serotypes were, with some exceptions, serum sensitive. The fact that some serum resistant isolates were avirulent suggested that other factors may be required for the full expression of virulence. The study also demonstrated that rainbow trout and brook trout (Salvelinus fontinalis) differ in their susceptibility to Y. ruckeri.
Assuntos
Atividade Bactericida do Sangue , Doenças dos Peixes/microbiologia , Truta , Yersiniose/veterinária , Yersinia/patogenicidade , Animais , Proteínas da Membrana Bacteriana Externa/análise , Técnicas de Tipagem Bacteriana , Inoculações Seriadas , Sorotipagem , Virulência , Yersinia/classificação , Yersinia/imunologia , Yersiniose/microbiologiaRESUMO
The outer membrane protein (OMP) profiles of 135 isolates of Yersinia ruckeri, obtained from nine European countries (100 isolates), North America (23 isolates), Australia (six isolates) and South Africa (two isolates), and including four reference strains, were examined by SDS-PAGE. Outer membranes were isolated by selective solubilisation of the cytoplasmic membrane with 0.5% (w/v) sodium N-lauroyl sarcosinate (Sarkosyl). Outer membrane proteins were stable after in vitro passage and there was no variation in OMP profiles due to colony selection. With the exception of a 39.5 kDa peptidoglycan-associated protein there was also no variation at different stages of the growth cycle. The 39.5 kDa protein was not produced during logarithmic growth phase but increased in abundance as the stationary phase progressed. Interstrain variation occurred in the possession of a 36.5 or 38 kDa heat-modifiable protein and in the possession of peptidoglycan-associated proteins in the molecular weight range 36.5 to 40.5 kDa. Based on variation of these proteins five OMP-types, designated OMP-types 1-5, were identified among the 135 isolates examined. Outer membrane protein analysis was demonstrated to be useful in epidemiological studies of Y. ruckeri.
Assuntos
Proteínas da Membrana Bacteriana Externa/análise , Yersinia/classificação , Animais , Austrália , Eletroforese em Gel de Poliacrilamida , Europa (Continente) , Doenças dos Peixes/microbiologia , Peso Molecular , América do Norte , Peptidoglicano/análise , Salmonidae , Solubilidade , África do Sul , Temperatura , Yersinia/análise , Yersiniose/microbiologia , Yersiniose/veterináriaRESUMO
OBJECTIVES: The objective of this project was to quantify the effects of geometry on the distribution of hepatic blood to the lungs in patients with a total cavo-pulmonary connection. The basis for this work is the supposition that hepatic blood is necessary for proper lung function. METHODS: Plastic models of these connections were made with varying degrees of offset between the inferior and superior vena cava and attached to an in vitro flow loop. Dye was injected into the inferior vena cava and its concentration quantified in each pulmonary artery. These data were converted to percentage concentration and distribution of hepatic blood to each lung. RESULTS: With no offset between the vena cava, hepatic blood distribution and concentration to each lung was similar to normal. For an offset of one or more diameters, hepatic blood tended to flow preferentially towards the nearest pulmonary artery with the opposite pulmonary artery exhibiting a deficit (<10% of normal). CONCLUSIONS: Distribution of hepatic blood to each lung was found to be a function of vena cava offset and pulmonary artery flow split. Under normal conditions, 60% of blood towards the right pulmonary artery, the hepatic blood distribution to both lungs could be maintained above 50% of normal if the inferior vena cava was offset towards the left pulmonary artery. Offsetting the inferior vena cava towards the right pulmonary artery jeopardized the delivery of hepatic blood to one lung.
Assuntos
Derivação Cardíaca Direita/métodos , Cardiopatias Congênitas/cirurgia , Circulação Hepática , Velocidade do Fluxo Sanguíneo , Humanos , Técnicas In Vitro , Modelos Anatômicos , Sensibilidade e Especificidade , Veia Cava Inferior/fisiopatologia , Veia Cava Inferior/cirurgiaRESUMO
In vitro methods of testing the efficiency of barium sulphate suspensions in delineating mucosal detail using canine cadaveric stomachs have been described in the literature. In this study a comparison is made between in vitro and in vivo tests in the stomach and small intestine of dogs, using several brands of barium sulphate. The results indicate that there is considerable variation in the behavior of these suspensions between the in vitro and in vivo tests particularly in the stomach. It is our view that in vitro tests of this sort are of little value for assessing the relative advantages and disadvantages of these suspensions in demonstrating mucosal detail.
Assuntos
Sulfato de Bário , Mucosa Gástrica/diagnóstico por imagem , Mucosa Intestinal/diagnóstico por imagem , Animais , Meios de Contraste , Cães , Intestino Delgado/diagnóstico por imagem , RadiografiaRESUMO
Thrombus formation on the surface of a variety of arterial catheters and guidewires has been studies in dogs. Heparin-bonding of catheters and guidewires greatly reduced surface thrombus deposition even in the most thrombogenic material tested, and under the conditions of these experiements heparin-bonding was more effective than systemic heparinization.
Assuntos
Cateterismo/efeitos adversos , Trombose/etiologia , Animais , Coagulação Sanguínea , Cateterismo/instrumentação , Cães , Artéria Femoral , Heparina , Polietilenos , Politetrafluoretileno , Aço Inoxidável , Trombose/prevenção & controleRESUMO
A number of barium sulphate suspensions showed varying patterns of stability when provoked with gastric secretion. The stability of the suspensions was affected by the pH, the mucin content and the volume of secretion used. These studies indicate that flocculation of the suspension in the presence of gastric residue decreases as the amount of undiluted barium sulphate in the mixture is increased.
Assuntos
Sulfato de Bário , Suco Gástrico , Adsorção , Floculação , Humanos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Mucinas , Pepsina A , SuspensõesRESUMO
The histopathological, microradiographic and ultrasonographic features of corresponding areas of 100 cadaveric prostates were examined and correlated statistically to investigate their relationship. Benign glands are seen to be related to reticular structure and mid-range echoes. Benign prostatic hyperplasia is related to microadenomatous structure and mid-range echoes, whilst cancer is related to amorphous structure and low echoes. A small number of cancers have irregular calcification present and these tumours are related to high echoes. The structure of the prostate gland is therefore related to its pathology and explains its ultrasound echogenicity.
Assuntos
Próstata/patologia , Hiperplasia Prostática/patologia , Neoplasias da Próstata/patologia , Humanos , Masculino , Microrradiografia , Hiperplasia Prostática/diagnóstico , Neoplasias da Próstata/diagnóstico , UltrassonografiaRESUMO
Thirty-five isolates of Pasteurella multocida from the vagina and respiratory tract of sheep were compared by analysing their capsular polysaccharide types and outer membrane protein profiles. The phylogenetic relationships of selected isolates with respect to reference strains of P. multocida were also determined by comparative 16S rRNA sequence analysis. Three capsular types, A, D and F, and three major outer membrane protein types were identified, and there were four different combinations of these characteristics which probably marked four individual clones of P. multocida. Strains representing three of these clones were recovered from cases of ovine pneumonia, whereas isolates of the fourth clone were associated exclusively with the vagina of healthy ewes and the liver of a dead septicaemic lamb on the same farm. Analysis of the 16S rRNA sequences showed that there was 100 per cent identity between representative pneumonic isolates and reference strains of P. multocida subspecies galliseptica and P. multocida subspecies multocida. The 16S rRNA genes of representative vaginal and liver isolates from the same farm were identical but differed from the other strains at one nucleotide position, providing strong evidence that the vaginal and liver isolates represent a distinct subpopulation of P. multocida.
Assuntos
Pulmão/microbiologia , Infecções por Pasteurella/veterinária , Pasteurella multocida/isolamento & purificação , Sorotipagem/veterinária , Doenças dos Ovinos/microbiologia , Vagina/microbiologia , Animais , Feminino , Pasteurella multocida/classificação , Pasteurella multocida/genética , RNA Ribossômico 16S/genética , OvinosRESUMO
Seed of Adonis microcarpa (pheasant's eye) fed at 5.6 g/kg of the diet induced virtually total feed refusal within 3 d in growing and finishing pigs. It also caused vomiting, rapid and shallow breathing and death in a minority. These effects were probably caused by cardiac glycosides whose structure and effects closely resemble those of digoxin. Feed intake and growth recovered within 2 weeks of removal of the seed.