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1.
Nat Commun ; 13(1): 4239, 2022 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-35869081

RESUMO

Bone and joint infections (BJI) are one of the most difficult-to-treat bacterial infection, especially in the era of antimicrobial resistance. Lytic bacteriophages (phages for short) are natural viruses that can selectively target and kill bacteria. They are considered to have a high therapeutic potential for the treatment of severe bacterial infections and especially BJI, as they also target biofilms. Here we report on the management of a patient with a pandrug-resistant Pseudomonas aeruginosa spinal abscess who was treated with surgery and a personalized combination of phage therapy that was added to antibiotics. As the infecting P. aeruginosa strain was resistant to the phages developed by private companies that were contacted, we set up a unique European academic collaboration to find, produce and administer a personalized phage cocktail to the patient in due time. After two surgeries, despite bacterial persistence with expression of small colony variants, the patient healed with local and intravenous injections of purified phages as adjuvant therapy.


Assuntos
Bacteriófagos , Terapia por Fagos , Infecções por Pseudomonas , Biofilmes , Humanos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa
2.
J Dairy Sci ; 102(4): 3295-3309, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30738682

RESUMO

Staphylococcus aureus is a highly contagious mastitis-causing pathogen infecting dairy cattle worldwide. Previous studies have shown the presence of different genotypes (GT) on farms. In Switzerland, Staph. aureus genotype B (GTB) is contagious, whereas GTC and other genotypes cause sporadic, noncontagious mastitis. In this study, we evaluated the epidemiological properties of Staph. aureus, together with its genotypes and spa types, on Swiss dairy farms. A total of 21 dairy farms were sampled throughout Switzerland; 10 farms were positive for the contagious Staph. aureus GTB and 11 farms were negative for GTB. Samples were taken from milk, body surfaces of dairy cattle and other animals, milkers, milking equipment, and environmental sites (e.g., parlor, washing room, stall floor, manger, and bedding). The epidemiology of Staph. aureus depended markedly on the genotype. Staphylococcus aureus GTB was associated with mammary gland, intramammary infections (IMI), and milking clusters, whereas GTC and other genotypes were related to cow and other animal surfaces and occasionally to environment. Genotype C was by far the most common subtype in cattle and was found on GTB-negative and GTB-positive farms. Each farm had a predominant genotype, such as GTB, GTC, GTA, or GTF, but a few farms were almost free from Staph. aureus. The genotypes and spa types of Staph. aureus detected in the noses of milkers clearly differed from those found in dairy cattle, other animals, milking equipment, and the environment. Exceptions were GTS (spa type t034) and GTF (t899), which crossed the species barrier. In most cases, however, the species barrier was maintained because Staph. aureus is adapted to a particular host and even to particular body sites. As biological properties differ among the genotypes, new guidelines to prevent IMI caused by different genotypes were established: classical measures to prevent IMI caused by contagious pathogens still hold for GTB but not for Staph. aureus genotypes that are opportunistic colonizers of bovine skin (e.g., GTC and GTA). For those genotypes, protection of the skin from minor lesions and wounds, particularly on the hocks, is essential.


Assuntos
Mastite Bovina/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/genética , Animais , Bovinos , Fazendas , Feminino , Genótipo , Mastite Bovina/epidemiologia , Mastite Bovina/metabolismo , Leite/microbiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/isolamento & purificação , Suíça/epidemiologia
3.
Epidemiol Mikrobiol Imunol ; 67(3): 114-120, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30602278

RESUMO

INTRODUCTION: The serovar Mozdok related leptospirosis in humans were not yet feasibly diagnosed using merely the standard micro-agglutination test (MAT) what was perhaps due to the impossibility to distinguish them from illnesses that are caused by Leptospira strains belonging to other serovars of the serogroup Pomona. On the contrary, leptospires of the Mozdok serovar were cultured from rodents and domestic animals world-wide including Central Europe where only Leptospira strains of the serovars Pomona and Mozdok are known to be present till now. STUDY OBJECTIVE: The aim of the study was to discover if leptospires of Mozdok serovar may cause human leptospirosis that remained hidden till now among infections diagnosed merely by MAT as Pomona illnesses. MATERIAL AND METHODS: The reference Leptospira strains of Pomona and Mozdok serovars (Pomona and 5621), as well as three endemic, and in some tests only two strains of human and pig origin (Simon, S-23, Pöstényi), and two strains of rodent provenance - Apodemus agrarius (M-210/98 and M-71/01) were used for this purpose. First, the endemic strains were assigned to one of the afore-mentioned two serovars by agglutinin cross-absorption tests performed using rabbit immune sera, monoclonal antibodies and random amplified polymorphic DNA methods. Afterwards, twenty-one sera of patients with a Pomona leptospirosis confirmed by MAT were examined by agglutinin absorption test (AAT). RESULTS: Based on the results of the mentioned laboratory method used, the endemic Leptospira strains of human and pig origin could be affiliated to the serovar Pomona, while those of rodent origin were classified as serovar Mozdok strains. Out of the 21 patients sera, an illness caused by the serovar Mozdok strains was found out in 13 cases and a disease caused by serovar Pomona strains in 8 cases. Their differentiation was made on the strength of the following results of AATs: All strains from the serovar Mozdok have completely absorbed antibodies (anti-Pomona and anti-Mozdok) from the tested sera, however following the absorption of these sera with the Pomona strains, high levels of residual antibodies reacting in MAT with the Mozdok strains have still persisted. In this way, it was possible to prove the Mozdok infection in thirteen patients. On the contrary, following the absorption of the sera with the strains of the serovar Pomona, a complete absorption of all antibodies (anti-Pomona and anti-Mozdok) was achieved in seven cases using the strain Simon, and in one case with the strain S-23, whereas after absorption using the Pomona strain, the residual antibodies were still present in all sera, and also in the majority of them when they were absorbed using the strains S-23 and Pöstényi. In this context, the Pomona infection was determined in the case of eight patients. Hence it follows that not all strains of the Pomona serovar were suitable for the AATs. CONCLUSION: The presence of the human Mozdok leptospirosis was confirmed for the first time by the use of the agglutinin absorption test. A clear correlation between the habitat areas of the A. agrarius and the patients who were infected with the strains of the Mozdok serovar was determined.


Assuntos
Leptospirose , Aglutininas , Animais , Anticorpos Antibacterianos , Humanos , Leptospira/classificação , Leptospirose/diagnóstico , Leptospirose/microbiologia , Coelhos , Sorotipagem , Eslováquia
4.
Pathologica ; 107(1): 37-42, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26591632

RESUMO

We report a case of a 76-year-old female with multiple lung nodules (Fig. 1 Rx). Pathologic evaluation of the lower left video-assisted thoracoscopic surgery (VATS) lobectomy VATS-lobectomy showed four nodules that were described as pulmonary epithelioid hemangio-endothelioma (PEH); the immunohistochemical stains showed that the neoplastic cells expressed CD31, a variable expression for factor VIII and a low expression of CD34. In the remaining parenchyma of the lobe, multiple nests of neuroendocrine cells were observed with immunohistochemical confirmation, and the diagnosis was diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH). To our knowledge, the association between PEH and DIPNECH has never been described in the literature.


Assuntos
Hemangioendotelioma Epitelioide/patologia , Neoplasias Pulmonares/patologia , Nódulos Pulmonares Múltiplos/patologia , Células Neuroendócrinas/patologia , Lesões Pré-Cancerosas/patologia , Idoso , Biomarcadores Tumorais/análise , Biópsia , Feminino , Hemangioendotelioma Epitelioide/química , Hemangioendotelioma Epitelioide/diagnóstico por imagem , Hemangioendotelioma Epitelioide/cirurgia , Humanos , Hiperplasia , Imuno-Histoquímica , Neoplasias Pulmonares/química , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/cirurgia , Nódulos Pulmonares Múltiplos/química , Nódulos Pulmonares Múltiplos/diagnóstico por imagem , Nódulos Pulmonares Múltiplos/cirurgia , Células Neuroendócrinas/química , Pneumonectomia/métodos , Lesões Pré-Cancerosas/química , Lesões Pré-Cancerosas/diagnóstico por imagem , Lesões Pré-Cancerosas/cirurgia , Valor Preditivo dos Testes , Cirurgia Torácica Vídeoassistida , Tomografia Computadorizada por Raios X , Resultado do Tratamento
5.
Bratisl Lek Listy ; 113(2): 70-2, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22394034

RESUMO

BACKGROUND: In a previous study (5), the constructed phylogenetic tree for leptospires belonging to 12 different serovars common in Central Europe made the prediction of serovar from knowing the genotype and vice versa possible. OBJECTIVE: The study was aimed at investigation of the usefulness of such procedure to distinguish in between at present to us available and worldwide accepted reference strains of pathogenic Leptospira serovars. MATERIAL AND METHODS: One hundred and seventy seven Leptospira strains representing different serovars were tested. DNA fingerprints of these strains were performed, digitally captured and as described earlier of those phylogenetic tree using different fingerprinting software was constructed using UPGMA clustering method with band matching by the Dice coefficient (5). RESULTS: At this tree, 145 of 177 Leptospira strains tested each took a unique position, and the remaining 32 strains were distributed at 15 different positions (each of 14 positions taken by two different strains and one position taken by four strains). CONCLUSION: The constructed phylogenetic tree likely to be very useful in prediction of Leptospira serovar in most cases of an infection so the saving time and being helpful in serovar identification of the pathogenic agent (Fig. 1, Ref. 9).


Assuntos
DNA Bacteriano/análise , Leptospira/genética , Sorotipagem , Impressões Digitais de DNA , Leptospira/classificação , Filogenia
7.
Micron ; 42(5): 456-60, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21316249

RESUMO

In this study we combine energy loss magnetic circular dichroism (EMCD) and energy filtered transmission electron microscopy (EFTEM) to map magnetic properties of nanoparticles. We show that it is a functional tool for investigating the magnetic behaviour of bio-mineralized magnetite crystals of Magnetospirillum magnetotacticum. We find that the spatial resolution of our experimental set-up is in the range of less than 2 nm. The results are compared with EMCD studies of abiogenic magnetite.


Assuntos
Nanopartículas de Magnetita/ultraestrutura , Magnetospirillum/ultraestrutura , Dicroísmo Circular/métodos , Microscopia Eletrônica de Transmissão/métodos
9.
Int J Antimicrob Agents ; 36(6): 531-6, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20947312

RESUMO

A prospective, observational, multicentre study was performed to assess the incidence, diagnosis, epidemiology and outcome of invasive mould infections (IMIs) reported to the Nationwide Austrian Aspergillus Registry. In total, 186 cases were recorded, corresponding to an annual incidence of 42 cases/1000 patients at risk or 2.36 cases/100000 inhabitants. Patients with acute myelogenous leukaemia (34%) and lung transplant recipients (17%) are currently at highest risk for IMI, followed by a mixed population with impaired immunity (14%). In total, 34%, 30% and 36% were proven, probable and possible cases of IMI. Predominant pathogens were Aspergillus spp. (67%), followed by the zygomycetes (28%). Voriconazole was the most frequently administered agent (38%), followed by caspofungin (20%) and posaconazole (19%). Eighty patients (43%) received antifungal prophylaxis for ≥7 days, 30% of whom (24 patients) suffered from a breakthrough infection. The overall crude 12-week mortality was 34%. Multivariate analysis showed that outcome and survival did not correlate with the status of fungal disease, breakthrough infection, fungal species or age (P>0.05). Aspergillosis remains the most commonly identified IMI amongst immunocompromised and/or immunosuppressed patients, but other moulds constitute a significant problem. Survival from IMIs appears to have improved and the main challenge is to overcome breakthrough fungal infections.


Assuntos
Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergilose/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Aspergilose/mortalidade , Áustria/epidemiologia , Feminino , Humanos , Hospedeiro Imunocomprometido , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Análise de Sobrevida , Resultado do Tratamento , Adulto Jovem
10.
J Microsc ; 231(3): 479-85, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18755003

RESUMO

Summary Pushing at the cell front is the business of lamellipodia and understanding how lamellipodia function requires knowledge of their structural organization. Analysis of extracted, critical-point-dried cells by electron microscopy has led to a current dogma that the lamellipodium pushes as a branched array of actin filaments, with a branching angle of 70 degrees , defined by the Arp2/3 complex. Comparison of different preparative methods indicates that the critical-point-drying-replica technique introduces distortions into actin networks, such that crossing filaments may appear branched. After negative staining and from preliminary studies by cryo-electron tomography, no clear evidence could be found for actin filament branching in lamellipodia. From recent observations of a sub-class of actin speckles in lamellipodia that exhibit a dynamic behaviour similar to speckles in the lamella region behind, it has been proposed that the lamellipodium surfs on top of the lamella. Negative stain electron microscopy and cryo-electron microscopy of fixed cells, which reveal the entire complement of filaments in lamellipodia show, however, that there is no separate, second array of filaments beneath the lamellipodium network. From present data, we conclude that the lamellipodium is a distinct protrusive entity composed of a network of primarily unbranched actin filaments. Cryo-electron tomography of snap-frozen intact cells will be required to finally clarify the three-dimensional arrangement of actin filaments in lamellipodia in vivo.


Assuntos
Pseudópodes/ultraestrutura , Citoesqueleto de Actina/ultraestrutura , Microscopia Crioeletrônica , Microscopia Eletrônica de Transmissão , Coloração Negativa
11.
Epidemiol Infect ; 135(8): 1266-73, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17313692

RESUMO

A phylogenetic tree, which distinguishes between the serovars and serogroups of leptospires common in Central Europe was constructed using an established RAPD procedure together with digital reading and evaluation (using different computer software programs) of the generated amplified DNA patterns. The application of this procedure has revealed a consistent correspondence between serogroup and genotype (position in constructed tree) in 69 cases, and serovar and genotype in 72 cases, of wild strains of leptospires. There was an agreement between serovar and genotype in cases of strains of Grippotyphosa, Pomona, Mozdok, Arborea and Sorexjalna as well as between serogroup and genotype in cases of Australis, Bataviae and Sejroe. With the procedure used in this study, it was not possible to distinguish between reference strains of serovars Jalna, Bratislava and Lora (all serogroup Australis) as well as between serovars Icterohaemorrhagiae and Copenhageni (both of serogroup Icterohaemorrhagiae). In contrast to this, wild strains belonging to serogroup Sejroe were distributed between Polonica, Istrica, Saxkoebing and Sejroe serovars. Endemic strains of leptospires tested, were also distinguishable.


Assuntos
Leptospira/classificação , Leptospira/isolamento & purificação , Leptospirose/microbiologia , Epidemiologia Molecular/métodos , Filogenia , Animais , Análise por Conglomerados , Impressões Digitais de DNA , DNA Bacteriano/genética , Genótipo , Humanos , Leptospira/genética , Leptospirose/epidemiologia , Técnica de Amplificação ao Acaso de DNA Polimórfico , Sorotipagem , Estatística como Assunto
12.
Homeopathy ; 94(2): 75-80, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15892486

RESUMO

BACKGROUND: Mortality in patients with severe sepsis remains high despite the development of several therapeutic strategies. The aim of this randomized, double-blind, placebo-controlled trial was to evaluate whether homeopathy is able to influence long-term outcome in critically ill patients suffering from severe sepsis. METHODS: Seventy patients with severe sepsis received homeopathic treatment (n = 35) or placebo (n = 35). Five globules in a potency of 200c were given at 12h interval during the stay at the intensive care unit. Survival after a 30 and 180 days was recorded. RESULTS: Three patients (2 homeopathy, 1 placebo) were excluded from the analyses because of incomplete data. All these patients survived. Baseline characteristics including age, sex, BMI, prior conditions, APACHE II score, signs of sepsis, number of organ failures, need for mechanical ventilation, need for vasopressors or veno-venous hemofiltration, and laboratory parameters were not significantly different between groups. On day 30, there was non-statistically significantly trend of survival in favour of homeopathy (verum 81.8%, placebo 67.7%, P= 0.19). On day 180, survival was statistically significantly higher with verum homeopathy (75.8% vs 50.0%, P = 0.043). No adverse effects were observed. CONCLUSIONS: Our data suggest that homeopathic treatment may be a useful additional therapeutic measure with a long-term benefit for severely septic patients admitted to the intensive care unit. A constraint to wider application of this method is the limited number of trained homeopaths.


Assuntos
Homeopatia/métodos , Sepse/tratamento farmacológico , APACHE , Idoso , Anti-Infecciosos/administração & dosagem , Quimioterapia Adjuvante , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor/métodos , Estudos Prospectivos , Sepse/fisiopatologia , Índice de Gravidade de Doença , Choque Séptico/tratamento farmacológico , Análise de Sobrevida , Resultado do Tratamento
13.
J Pharmacol Exp Ther ; 297(2): 612-9, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11303050

RESUMO

Severe hemorrhage lowers arterial pressure by suppressing sympathetic activity. The central mechanism that initially triggers the fall in arterial pressure evoked by hemorrhage is not well understood, although opioid neurons are thought to play a role. This study tested the hypothesis that hemorrhagic hypotension is mediated by delta opioid receptors in the ventrolateral periaqueductal gray (vlPAG), a region importantly involved in opioid analgesia. Depressor sites were first identified by microinjecting DL-homocysteic acid (20 nmol/0.1 microl) or beta-endorphin (0.5 nmol/0.1 microl) into the vlPAG of halothane-anesthetized rats. Consistent with earlier reports, DL-homocysteic acid injection into the caudal vlPAG lowered arterial pressure and heart rate; beta-endorphin evoked a comparable depressor response, but did not affect heart rate. Naloxone or selective opioid receptor antagonists were subsequently injected into the vlPAG 5 min before hemorrhage (1.9 or 2.5 ml/100 g of body weight over 20 min) was initiated using the same stereotaxic coordinates. Naloxone injection into the caudal vlPAG completely prevented the fall in arterial pressure evoked by hemorrhage. The response was dose-dependent and evident with both fixed volume and fixed pressure hemorrhage. The delta opioid receptor antagonist naltrindole inhibited hemorrhagic hypotension significantly in both conscious and anesthetized rats but mu and kappa receptor antagonists were ineffective. beta-Endorphin(1--27), an endogenous opioid receptor antagonist, was also significantly inhibitory. Naltrindole was ineffective when injected into the dorsolateral periaqueductal gray and did not influence cardiovascular function in nonhemorrhaged animals. These data support the hypothesis that hemorrhagic hypotension is mediated by delta opioid receptors in the vlPAG.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Hemorragia/fisiopatologia , Homocisteína/análogos & derivados , Naltrexona/análogos & derivados , Substância Cinzenta Periaquedutal/fisiologia , Receptores Opioides delta/antagonistas & inibidores , Animais , Homocisteína/administração & dosagem , Homocisteína/farmacologia , Masculino , Microinjeções , Naloxona/administração & dosagem , Naloxona/farmacologia , Naltrexona/administração & dosagem , Naltrexona/farmacologia , Antagonistas de Entorpecentes/administração & dosagem , Antagonistas de Entorpecentes/farmacologia , Substância Cinzenta Periaquedutal/anatomia & histologia , Ratos , Ratos Sprague-Dawley , beta-Endorfina/administração & dosagem , beta-Endorfina/farmacologia
14.
Phys Rev Lett ; 86(13): 2802-5, 2001 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-11290043

RESUMO

We present the first direct experimental evidence for the charge excess in high-energy particle showers and corresponding radio emission predicted nearly 40 years ago by Askaryan. We directed picosecond pulses of GeV bremsstrahlung photons at the SLAC Final Focus Test Beam into a 3.5 ton silica sand target, producing electromagnetic showers several meters long. A series of antennas spanning 0.3 to 6 GHz detected strong, subnanosecond radio-frequency pulses produced by the showers. Measurements of the polarization, coherence, timing, field strength vs shower depth, and field strength vs frequency are completely consistent with predictions. These measurements thus provide strong support for experiments designed to detect high-energy cosmic rays such as neutrinos via coherent radio emission from their cascades.

15.
Brain Res ; 894(2): 316-20, 2001 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-11251208

RESUMO

Interleukin-1beta (IL-1beta) and other cytokines produce fever by stimulating prostaglandin E(2) (PGE(2)) synthesis in thermoregulatory regions of the preoptic area and anterior hypothalamus (POA/AH). Prostaglandin E(2) is thought to raise body temperature, at least in part, by stimulating beta-endorphin release from pro-opiomelanocortin neurons that innervate the POA/AH. In this study, we investigated whether glycyl-glutamine (beta-endorphin(30-31)), an inhibitory dipeptide synthesized from beta-endorphin post-translationally, inhibits IL-1beta and PGE(2)-induced hyperthermia. Hyperthermic sites were identified by microinjecting PGE(2) (3 fmol/1 microl) into the medial preoptic area (mPOA) of conscious, unrestrained rats. Interleukin-1beta (1 U) injection into the same PGE(2) responsive thermogenic sites in the mPOA elicited a prolonged rise in colonic temperature (T(c)) (+1.02+/-0.06 degrees C) that persisted for at least 2 h. Glycyl-glutamine (3 nmol) co-injection into the mPOA inhibited IL-1beta thermogenesis completely (T(c)=-0.18+/-0.22 degrees C). Glycyl-glutamine had no effect on body temperature when given alone to normothermic rats. Co-injection of individual amino acids, glycine and glutamine (3 nmol each amino acid), failed to influence IL-1beta-induced thermogenesis, which indicates that Gly-Gln hydrolysis does not explain its inhibitory activity. Glycyl-glutamine (3 nmol) also prevented the rise in body temperature produced by PGE(2) (PGE(2)=0.89+/-0.05 degrees C; PGE(2) plus Gly-Gln=-0.16+/-0.14 degrees C), consistent with evidence that PGE(2) mediates IL-1beta-induced fever. These findings demonstrate that Gly-Gln inhibits the thermogenic response to endogenous pyrogens.


Assuntos
Regulação da Temperatura Corporal/efeitos dos fármacos , Dinoprostona/antagonistas & inibidores , Dipeptídeos/farmacologia , Interleucina-1/antagonistas & inibidores , Inibição Neural/efeitos dos fármacos , Animais , Regulação da Temperatura Corporal/imunologia , Dinoprostona/imunologia , Interleucina-1/imunologia , Masculino , Inibição Neural/imunologia , Pró-Opiomelanocortina/química , Ratos , Ratos Sprague-Dawley
16.
Artigo em Francês | MEDLINE | ID: mdl-11543270

RESUMO

The aim of this work was to know if the venous tone measured in vivo in rat was decreased after 3-week tail suspension, a ground-based model to simulate the effects of microgravity. Arterial and venous pressure measurements during upright tilt did not show any cardiovascular deconditioning. A longer period of tail suspension appears to be necessary to induce changes in venous tone.


Assuntos
Pressão Sanguínea/fisiologia , Elevação dos Membros Posteriores , Simulação de Ausência de Peso/métodos , Animais , Descondicionamento Cardiovascular/fisiologia , Pressão Venosa Central/fisiologia , Hemodinâmica/fisiologia , Masculino , Ratos , Ratos Wistar
17.
Alcohol ; 16(2): 101-7, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9665311

RESUMO

Recent reports show that central beta-endorphin (1-31) injection augments the volitional intake of alcohol. Correspondingly, alcohol drinking stimulates beta-endorphin (1-31) release from the hypothalamus of the rat. Glycyl-l-glutamine (Gly-Gln) is produced in beta-endorphin-containing neurons and is co-released with beta-endorphin(1-31) and other processing products. Because Gly-Gln is apparently an endogenous antagonist of beta-endorphin(1-31) in several systems, the present study was designed to investigate the hypothesis that Gly-Gln injected i.c.v. would alter voluntary alcohol drinking in the genetic, high-alcohol-preferring P rat. After a guide tube was implanted stereotaxically above the lateral cerebral ventricle, the rats were offered 3-30% alcohol over 10 days, and then given their maximally preferred concentration of alcohol in the presence of water for the remainder of the experiment. Gly-Gln or artificial cerebrospinal fluid (CSF) vehicle then was injected i.c.v. in a dose of 10 or 100 nmol for 3 consecutive days, which was followed by a 7-day postinjection interval. Gly-Gln suppressed significantly the intakes of alcohol in terms of both g/kg and proportion to total fluid. During the postinjection days, alcohol drinking continued to be suppressed, whereas neither the daily intakes of food or water nor the body weights of the rats were changed. The present results are consistent with the concept of a functional antagonism by Gly-Gln of the role of beta-endorphin(1-31) in mediating certain central functions. These results demonstrate that alcohol consumption is suppressed by the direct intracerebral application of this unique peptide.


Assuntos
Consumo de Bebidas Alcoólicas/genética , Dipeptídeos/farmacologia , Inibição Neural , Animais , Preferências Alimentares , Injeções Intraventriculares , Masculino , Ratos , Ratos Mutantes , beta-Endorfina/antagonistas & inibidores
18.
J Gravit Physiol ; 5(1): P35-6, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11542355

RESUMO

The purpose of the present work was to study in vivo in rat the consequences of repeated exposures to sustained +Gz centrifugations on the venous pressure and on the venous tone, that one evaluated by measuring the equilibrium pressure of all vessels in the circulation when the flow is null or MCFP (mean circulatory filling pressure).


Assuntos
Aceleração , Pressão Venosa Central/fisiologia , Hipergravidade , Pressão Venosa/fisiologia , Adaptação Fisiológica , Animais , Circulação Sanguínea/fisiologia , Pressão Sanguínea/fisiologia , Centrifugação , Masculino , Ratos
19.
J Gravit Physiol ; 5(1): P47-8, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11542361

RESUMO

Cardiovascular deconditioning observed in humans during spaceflight has been suggested to be related in part to changes in venous compliance, mechanisms including skeletal muscle deconditioning. However, increased venous compliance was observed during very short term simulations (24 to 48 hours), and during an over 28-day simulation the hyperdistensibility tended to decrease whereas the muscular changes were still present (2). In the first case, muscular changes can not explain the venous alterations because of the short delay. In the second case, the relationship between muscular and venous alterations disappeared. Finally, it is suggested that factors other than muscular ones could explain the changes in venous compliance observed during spaceflights. The fact that orthostatic hypotension has never been observed after hindlimb suspension in the rat raises issue with the use of tail-suspended rats as a valid model for the study of the mechanisms involved in cardiovascular deconditioning induced by spaceflight in humans. However, in vitro altered responsiveness of the vena cava to norepinephrine were observed in rat after spaceflight and tail suspension. The purpose of the experiments was to verify if any change occurs in venous tone measured in vivo in rats after three-week tail suspension.


Assuntos
Pressão Sanguínea/fisiologia , Elevação dos Membros Posteriores , Pressão Venosa/fisiologia , Simulação de Ausência de Peso/métodos , Animais , Pressão Venosa Central/fisiologia , Complacência (Medida de Distensibilidade) , Masculino , Ratos , Veias/anatomia & histologia , Veias/fisiologia
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