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3.
J Anim Sci ; 95(3): 1345-1355, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28380542

RESUMO

Condensed tannins (CT) may decrease greenhouse gas emissions and alter the site of N excreted by ruminants. We evaluated the effect of top-dressing a steam-flaked corn-based finishing diet (14.4% CP and NEg 1.47 Mcal/kg) for beef cattle with a commercially available CT extract at 3 levels (0, 0.5, and 1.0% of diet, DM basis). Angus-crossbred steers ( = 27; 350 ± 32 kg initial BW) were individually fed via Calan gates for 126 d. Diet digestibility and N balance were estimated after 34 and 95 d on feed (Phase 1 and Phase 2, respectively) using titanium dioxide as a marker of fecal output and the creatinine:BW ratio as a marker for urine output. Ruminal CH and metabolic CO fluxes were measured using a GreenFeed system (C-Lock Inc., Rapid City, SD) for 2 sampling periods that coincided with fecal and urine sampling. Urine energy loss was estimated from urine N excretion, assuming all excreted N was urea. Oxygen consumption was estimated from CO production assuming a respiratory quotient of 1.05. Average daily gain (2.08, 2.14, and 2.08 kg/d for 0, 0.5, and 1.0% CT, respectively) and G:F did not differ ( = 0.88) among treatments. Starch intake and OM intake did not differ ( ≥ 0.42) among treatments during each phase. Apparent total tract starch digestibility during Phase 1 linearly decreased ( = 0.04) with inclusion of CT. Apparent total tract digestibility of OM and starch were not different among treatments ( ≥ 0.13) during Phase 2. Nitrogen intake did not differ ( ≥ 0.16) among treatments during each phase, but fecal N excretion linearly increased ( = 0.05) with inclusion of CT during Phase 1. Urinary N excretion was not different ( ≥ 0.39) among treatments during both phases, but urinary N as a proportion of total N excretion linearly decreased ( = 0.01) when CT was included in the diet during Phase 1. Retained N was not different ( ≥ 0.27) among treatments during each phase. Fluxes of CO were similar ( ≥ 0.37) among treatments during both phases. No differences ( ≥ 0.23) were observed for percentage of GE intake lost as CH (2.99, 3.12, and 3.09% in Phase 1 and 3.54, 3.55, and 4.35% in Phase 2) for 0, 0.5, and 1.0% CT, respectively. No difference ( ≥ 0.42) was observed for heat production lost as a percent of GE intake during both phases. Growth performance, gas emissions, and energetic losses were not affected by the inclusion CT in a steam-flaked corn-based finishing diet.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Suplementos Nutricionais , Nitrogênio/metabolismo , Proantocianidinas/farmacologia , Animais , Monóxido de Carbono/metabolismo , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Digestão/efeitos dos fármacos , Fezes/química , Fermentação/efeitos dos fármacos , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Masculino , Oxigênio/metabolismo , Proantocianidinas/isolamento & purificação , Rúmen/metabolismo , Amido/metabolismo , Vapor , Ureia/metabolismo , Urina/química , Zea mays
4.
Radiother Oncol ; 122(2): 242-247, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28126329

RESUMO

PURPOSE: To evaluate the feasibility and impact of using a novel advanced PET auto-segmentation method in Head and Neck (H&N) radiotherapy treatment (RT) planning. METHODS: ATLAAS, Automatic decision Tree-based Learning Algorithm for Advanced Segmentation, previously developed and validated on pre-clinical data, was applied to 18F-FDG-PET/CT scans of 20 H&N patients undergoing Intensity Modulated Radiation Therapy. Primary Gross Tumour Volumes (GTVs) manually delineated on CT/MRI scans (GTVpCT/MRI), together with ATLAAS-generated contours (GTVpATLAAS) were used to derive the RT planning GTV (GTVpfinal). ATLAAS outlines were compared to CT/MRI and final GTVs qualitatively and quantitatively using a conformity metric. RESULTS: The ATLAAS contours were found to be reliable and useful. The volume of GTVpATLAAS was smaller than GTVpCT/MRI in 70% of the cases, with an average conformity index of 0.70. The information provided by ATLAAS was used to grow the GTVpCT/MRI in 10 cases (up to 10.6mL) and to shrink the GTVpCT/MRI in 7 cases (up to 12.3mL). ATLAAS provided complementary information to CT/MRI and GTVpATLAAS contributed to up to 33% of the final GTV volume across the patient cohort. CONCLUSIONS: ATLAAS can deliver operator independent PET segmentation to augment clinical outlining using CT and MRI and could have utility in future clinical studies.


Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Radioterapia de Intensidade Modulada , Algoritmos , Feminino , Fluordesoxiglucose F18 , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Planejamento da Radioterapia Assistida por Computador , Carga Tumoral
6.
Int J Clin Pract ; 68(2): 203-15, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24355040

RESUMO

BACKGROUND: The association between testosterone deficiency and insulin resistance in men with type 2 diabetes is well established. Current Endocrine Society and European Association of Urology guidelines recommend the measurement of testosterone levels in all men with type 2 diabetes and in men suffering from erectile dysfunction. It is recognised that a range of physical symptoms appear as the testosterone level falls but few studies have addressed the threshold at which symptoms improve with physiological replacement. We report the first double-blind placebo-controlled study conducted exclusively in a male type 2 diabetes population to assess the metabolic changes with testosterone replacement. METHODS: The type 2 diabetes registers of seven general practices were screened to establish the prevalence of low testosterone and the associations with diabetes control. Of 550 eligible patients approached, 488 men (mean age 62.6) consented to take part in screening with a morning testosterone level, assessed between 8 and 11 am. This identified 211 patients for a double-blind placebo-controlled study of long acting testosterone undecanoate (TU) 1000 mg lasting 30 weeks followed by 52 weeks of open label use. The population was divided into a SEVERE group with either total testosterone (TT) of 8 nmol/l or less or free testosterone (FT) 180 pmol/l or less or a MILD group with TT 8.1-12 nmol/l or FT 181-250 pmol/l. RESULTS: Men in the SEVERE group increased mean through TT from 7.73 nmol/l at baseline to 9.93 at 30 weeks and the MILD group from 10.47 to 11.94. The SEVERE group showed marked improvement in sexual function, but no significant improvement in metabolic parameters. The MILD group showed no improvement in sexual function, but significant improvement in weight, body mass index, waist circumference and Hospital Anxiety and Depression Scale. Improvement was seen in all parameters during 52 weeks open label treatment where trough TT levels approached 15 nmol/l. Baseline prostate-specific antigen (PSA) was lower in the SEVERE group and increased with TU for 30 weeks and then stabilised. There was no increase in PSA with treatment in the MILD group. CONCLUSIONS: Testosterone undecanoate significantly improves sexual parameters and Ageing Male Symptom Score, but not metabolic factors at 30 weeks in men with SEVERE testosterone deficiency syndrome (TDS). In men with MILD TDS, significant improvements in metabolic but not sexual parameters were seen, suggesting that there are threshold levels for response to testosterone replacement therapy and that trials of therapy need to achieve sustained therapeutic levels to be effective. PSA showed minor rises, but only for 30 weeks in the SEVERE group.


Assuntos
Androgênios/administração & dosagem , Diabetes Mellitus Tipo 2/complicações , Hipogonadismo/tratamento farmacológico , Testosterona/análogos & derivados , Testosterona/deficiência , Adulto , Idoso , Idoso de 80 Anos ou mais , Androgênios/efeitos adversos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Método Duplo-Cego , Esquema de Medicação , Humanos , Hipoglicemiantes/uso terapêutico , Hipogonadismo/sangue , Hipogonadismo/complicações , Injeções Intramusculares , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Estudos Prospectivos , Disfunções Sexuais Fisiológicas/tratamento farmacológico , Testosterona/administração & dosagem , Testosterona/efeitos adversos , Testosterona/sangue , Resultado do Tratamento
7.
J Anim Sci ; 90(11): 3988-4000, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22665652

RESUMO

The growing ethanol industry in the Southern Great Plains has recently increased the use of wet distillers grains with solubles (WDGS) in beef cattle finishing diets. Two experiments were conducted to evaluate odorous compound production in urine and feces of feedlot steers fed diets with different concentrations of WDGS and different grain processing methods. In both experiments, a Latin square design was used. In Exp. 1, a 2× 2 factorial arrangement of treatments was used and the factors consisted of corn processing method [steam-flaked corn (SFC) or dry-rolled corn (DRC)] and inclusion of corn-based WDGS (0 or 30% on a DM basis). Thus, the 4 treatment combinations consisted of: 1) SFC-based diet with 0% WDGS (SFC-0); 2) SFC-based diet with 30% WDGS (SFC-30); 3) DRC-based diet with 0% WDGS (DRC-0); and 4) DRC-based diet with 30% WDGS (DRC-30). In Exp. 2, all diets were based on SFC and the 4 treatments consisted of: 1) 0% WDGS (SFC-0); 2) 15% WDGS (SFC-15); 3) 30% WDGS (SFC-30); and 4) 45% WDGS (SFC-45). In both experiments, diets were balanced for degradable intake protein and ether extract by the addition of cottonseed meal and fat. Fecal slurries were prepared from a 5-d composite of urine and feces collected from each treatment. The slurries were analyzed using a gas chromatograph for VFA, phenol, p-cresol, indole, skatole, hydrogen, methane (CH(4),) and total gas production. In Exp. 1, the DRC fecal slurries had greater initial total VFA concentration compared with the SFC-based slurries and accumulated a greater concentration of total gas throughout the incubation; however, the SFC-based manure resulted in more CH(4) production. In Exp. 2, total VFA concentrations did not differ across all fecal slurries initially and on d 28; however, throughout the incubation, slurries with 0 and 15% WDGS had the greatest total VFA concentration. Overall, the presence of starch in the feces was likely the determining factor for the accumulation of odorous compounds in the fecal slurries initially, which was especially evident in diets including DRC, and once methanogenic microorganisms were established they likely converted VFA to CH(4).


Assuntos
Bovinos/fisiologia , Manipulação de Alimentos/métodos , Gases , Esterco/análise , Odorantes , Zea mays/química , Ração Animal/análise , Animais , Dieta/veterinária , Relação Dose-Resposta a Droga , Ácidos Graxos Voláteis , Masculino
8.
QJM ; 101(7): 545-8, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18443004

RESUMO

BACKGROUND: Endoscopic oesophageal stent insertion is a widely used procedure to alleviate dysphagia caused by malignant strictures of the oesophagus and gastric cardia. It can, however, be associated with significant complications, mortality and morbidity. AIM AND METHOD: This retrospective case note study was undertaken to assess success rates, complications and mortality of oesophageal stenting when undertaken in a UK District General Hospital (DGH) setting. Patients who underwent oesophageal stenting for malignant disease from January 2000 to January 2006 were included. RESULTS: Of the 137 patients studied, oesophageal adenocarcinoma was present in 57% of patients, squamous cell oesophageal carcinoma in 37% and gastric adenocarcinoma in 6%. Indications for stent insertion were: presence of non-resectable tumours (65%), co-morbidities that contraindicated surgery (25%), refusal by patients for surgery for potentially resectable disease (6%) and a need for enhanced oral nutrition prior to surgery (4%). Prior to stenting 86.4% of patients suffered from advanced dysphagia. A significant improvement in symptoms was seen in 94% of patients. Discharge from hospital was within 48 h in 45% of cases. Chest pain was experienced by 13.9% of patients and serious acute stent-related complications (perforation or bleeding) occurred in 5.8% of patients. Overall 41.6% of patients had at least one complication. Mortality was 4.4% at 7 days and 24.8% at 30 days. CONCLUSION: Oesophageal stent insertion proved to be an effective palliation of dysphagia in group studied. It is a relatively safe procedure with a low rate of serious acute complications (5.8%) and can be done as a short stay in many patients.


Assuntos
Transtornos de Deglutição/terapia , Neoplasias Esofágicas/cirurgia , Cuidados Paliativos/métodos , Stents , Neoplasias Gástricas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos de Deglutição/mortalidade , Transtornos de Deglutição/prevenção & controle , Neoplasias Esofágicas/complicações , Feminino , Hospitais de Distrito , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Stents/efeitos adversos , Neoplasias Gástricas/complicações , Taxa de Sobrevida , Resultado do Tratamento
9.
Infect Immun ; 69(6): 4116-9, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11349084

RESUMO

Lack of interleukin-6 (IL-6) during Pseudomonas aeruginosa corneal infection leads to more severe disease with changes in neutrophil recruitment. Exogenous IL-6 leads to increased efficiency of neutrophil recruitment and reduced bacterial loads in corneal infection in both IL-6 gene knockout and wild-type mice. This may be mediated by IL-6 increasing the production of corneal macrophage inflammatory protein 2 and intercellular cell adhesion molecule 1. We conclude that effective recruitment of neutrophils into the cornea is dependent on the production of IL-6 and that early augmentation of IL-6 may be protective in corneal infection.


Assuntos
Doenças da Córnea/imunologia , Interleucina-6/administração & dosagem , Interleucina-6/imunologia , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa , Animais , Quimiocina CXCL2 , Quimiocinas/metabolismo , Córnea/imunologia , Córnea/patologia , Doenças da Córnea/microbiologia , Doenças da Córnea/patologia , Molécula 1 de Adesão Intercelular/metabolismo , Camundongos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/imunologia
10.
Prim Care Update Ob Gyns ; 8(1): 48-51, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11164354

RESUMO

Sjogren's syndrome is a chronic progressive autoimmune disorder manifested predominately by xerostomia (dry mouth) and keratoconjunctivitis sicca (dry eyes). It can also affect many body systems. Up to 5% of people over the age of 60 years have primary Sjogren's syndrome, and approximately one third of patients present with extraglandular (systemic) manifestations. This disease is seen mostly in middle-aged women, with a small but significant proportion of these women developing lymphoid neoplasia. The exact etiology is still unknown. This autoimmune disorder is characterized by B-cell activation, the production of numerous auto-antibodies, and the loss of immune tolerance. Salivary gland biopsy remains the most helpful diagnostic test. Treatment is aimed at moisture replacement, which alleviates the discomfort and slows the destructive process. Because of its prevalence in older women, the obstetrician-gynecologist must be aware of the diagnostic and therapeutic approach to Sjogren's syndrome.

11.
Immunol Cell Biol ; 78(6): 646-8, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11114976

RESUMO

Intestinal parasitic infection is still a major problem in humans and animals, yet host immunity against gut parasitic infection remains partially understood. Eosinophilia and mastocytosis are features of such infection that have been shown to be genetically controlled. The expression of IL-6 is detected in eosinophils, mast cells and neutrophils and may be responsible for the regulation of leucocytes at infective sites. The relationships between IL-6 expression, eosinophilia, mastocytosis and host immunity remain unclear. In the present report, a close correlation between IL-6 mRNA+ cells, eosinophilia, mastocytosis and worm expulsion is demonstrated, which may indicate a role for IL-6 in regulation of host immunity against intestinal parasite infection.


Assuntos
Interleucina-6/biossíntese , Nippostrongylus/imunologia , Infecções por Strongylida/imunologia , Ativação Transcricional , Animais , Eosinofilia/imunologia , Eosinófilos/imunologia , Hibridização In Situ , Interleucina-6/genética , Intestino Delgado/imunologia , Contagem de Leucócitos , Mastócitos/imunologia , Mastocitose/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , RNA Mensageiro/biossíntese , Infecções por Strongylida/parasitologia , Infecções por Strongylida/patologia
12.
Virology ; 275(2): 306-17, 2000 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-10998331

RESUMO

Varicella-zoster virus is considered to have one of the most stable genomes of all human herpesviruses. In 1998, we reported the unanticipated discovery of a wild-type virus that had lost an immunodominant B-cell epitope on the gE ectodomain (VZV-MSP); the gE escape mutant virus exhibited an unusual pattern of egress. Further studies have now documented a markedly enhanced cell-to-cell spread by the mutant virus in cell culture. This property was investigated by laser scanning confocal microscopy combined with a software program that allows the measurement of pixel intensity of the fluorescent signal. For this new application of imaging technology, the VZV immediate early protein 62 (IE 62) was selected as the fluoresceinated marker. By 48 h postinfection, the number of IE 62-positive pixels in the VZV-MSP-infected culture was nearly fourfold greater than the number of pixels in a culture infected with a low-passage laboratory strain. Titrations by infectious center assays supported the above image analysis data. Confirmatory studies in the SCID-hu mouse documented that VZV-MSP spread more rapidly than other VZV strains in human fetal skin implants. Generally, the cytopathology and vesicle formation produced by other strains at 21 days postinfection were demonstrable with VZV-MSP at 14 days. To assess whether additional genes were contributing to the unusual VZV-MSP phenotype, approximately 20 kb of the VZV-MSP genome was sequenced, including ORFs 31 (gB), 37 (gH), 47, 60 (gL), 61, 62 (IE 62), 66, 67 (gI), and 68 (gE). Except for a few polymorphisms, as well as the previously discovered mutation within gE, the nucleotide sequences within most open reading frames were identical to the prototype VZV-Dumas strain. In short, VZV-MSP represents a novel variant virus with a distinguishable phenotype demonstrable in both infected cell cultures and SCID-hu mice.


Assuntos
Genes Virais , Herpesvirus Humano 3/genética , Proteínas do Envelope Viral/genética , Animais , Células Cultivadas , Variação Genética , Herpesvirus Humano 3/crescimento & desenvolvimento , Herpesvirus Humano 3/isolamento & purificação , Humanos , Camundongos , Camundongos SCID , Microscopia Confocal , Dados de Sequência Molecular , Mutação , Fases de Leitura Aberta , Fenótipo , Fosfotransferases/genética , Reação em Cadeia da Polimerase
13.
Am J Physiol Regul Integr Comp Physiol ; 279(2): R657-65, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10938257

RESUMO

The effects of thermal acclimation were investigated in the common carp Cyprinus carpio L. Acclimation and acute temperature effects were tested during ontogeny from larval [9.5 mm total length (L)] to juvenile (69.0 mm L) stages and between 8 and 21 degrees C. The myosin heavy chain (MHC) composition, myofibrillar Mg(2+)-Ca(2+)-ATPase activity, and muscle strains showed significant thermal acclimation effects. MHCs were only expressed in an acclimation temperature-dependent fashion in fish longer than 37 mm. During fast starts, the temperature had a significant effect on the white muscle strain (33% increase and 50% decrease with increasing acclimation and acute temperature, respectively) and contraction duration (25% decrease with increasing acute temperature). Increases in hydrodynamic efficiency (0.19 to 0.38) and hydrodynamic power requirements (Q(10) = 3.2) occurred with increasing acute temperature (10 to 20 degrees C). Competing hypotheses about the evolutionary significance of the temperature acclimation response were tested. Acclimation extended the temperature range for fast-start behavior, but no improvements in performance at the whole animal level were found between 8 and 21 degrees C.


Assuntos
Aclimatação/fisiologia , Evolução Biológica , Carpas/fisiologia , Temperatura Alta , Animais , ATPase de Ca(2+) e Mg(2+)/metabolismo , Carpas/metabolismo , Contração Muscular/fisiologia , Músculos/metabolismo , Músculos/fisiologia , Miofibrilas/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Isoformas de Proteínas/metabolismo , Natação/fisiologia
14.
Nat Cell Biol ; 2(5): 288-95, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10806480

RESUMO

When co-translationally inserted into endoplasmic reticulum (ER) membranes, newly synthesized proteins encounter the lumenal environment of the ER, which contains chaperone proteins that facilitate the folding reactions necessary for protein oligomerization, maturation and export from the ER. Here we show, using a temperature-sensitive variant of vesicular stomatitis virus G protein tagged with green fluorescent protein (VSVG-GFP), and fluorescence recovery after photobleaching (FRAP), the dynamics of association of folded and misfolded VSVG complexes with ER chaperones. We also investigate the potential mechanisms underlying protein retention in the ER. Misfolded VSVG-GFP complexes at 40 degrees C are highly mobile in ER membranes and do not reside in post-ER compartments, indicating that they are not retained in the ER by immobilization or retrieval mechanisms. These complexes are immobilized in ATP-depleted or tunicamycin-treated cells, in which VSVG-chaperone interactions are no longer dynamic. These results provide insight into the mechanisms of protein retention in the ER and the dynamics of protein-folding complexes in native ER membranes.


Assuntos
Retículo Endoplasmático/química , Retículo Endoplasmático/metabolismo , Glicoproteínas de Membrana , Dobramento de Proteína , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Antibacterianos/farmacologia , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Células COS , Ditiotreitol/farmacologia , Genes Reporter , Glicosilação , Proteínas de Fluorescência Verde , Indicadores e Reagentes/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Temperatura , Tunicamicina/farmacologia
15.
Immunol Cell Biol ; 78(1): 1-4, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10651922

RESUMO

Pseudomonas aeruginosa can cause ulcerative bacterial keratitis. A feature of keratitis is the rapid infiltration of the avascular corneal stroma by neutrophils. KC is a potent neutrophil chemokine. The present study used a mouse model of ocular infection to assess the relationship between KC and inflammation in the cornea in response to challenge with a strain of P. aeruginosa causing keratitis. Low levels of KC mRNA and protein were detected by in situ hybridization and ELISA, respectively, in unchallenged corneas. Dramatically increased numbers of KC mRNA+ cells were present in P. aeruginosa strain 6294-challenged corneas. Expression of KC mRNA was found to be up-regulated in the corneal epithelium in response to wounding alone. The KC mRNA+ cells were located in the epithelium and corresponding to infiltrating neutrophils cells in the stroma. Quantification of KC protein at different time points showed peak levels at 8 h of bacterial challenge. These results suggest that KC may be involved with the regulation of leucocyte infiltration early during bacterial keratitis.


Assuntos
Córnea/imunologia , Citocinas/biossíntese , Mediadores da Inflamação/metabolismo , Pseudomonas aeruginosa/imunologia , Pseudomonas aeruginosa/patogenicidade , Animais , Quimiocina CXCL1 , Quimiocinas , Quimiocinas CXC , Córnea/microbiologia , Citocinas/genética , Hibridização In Situ , Ceratite/etiologia , Ceratite/genética , Ceratite/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Neutrófilos/imunologia , Infecções por Pseudomonas/etiologia , Infecções por Pseudomonas/genética , Infecções por Pseudomonas/imunologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
16.
Infect Immun ; 67(5): 2497-502, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10225913

RESUMO

Strains of Pseudomonas aeruginosa causing keratitis can be either cytotoxic (6206) or invasive (6294), while a strain (Paer1) causing contact lens-induced acute red eye has been shown to be neither. In situ hybridization was used to examine the location and identity of cells expressing interleukin-6 (IL-6) mRNA in the murine cornea and changes in expression in response to infection with different strains of P. aeruginosa. The number of IL-6-positive cells was determined by image analysis. IL-6 protein levels were measured by an enzyme-linked immunosorbent assay. BALB/c mice were challenged by use of the wounded-cornea model with P. aeruginosa 6294, 6206, or Paer1 (2 x 10(6) CFU). At time intervals up to 24 h, postchallenge corneal tissue was probed for IL-6 mRNA. IL-6 mRNA expression was rapidly elevated in the epithelium in response to strains 6294 and 6206. At the conclusion of the experiments, infiltrating inflammatory cells also stained positively for IL-6 mRNA. In contrast, corneas challenged with strain Paer1 showed significant upregulation of IL-6 mRNA only at 4 h postchallenge. Three distinct patterns of IL-6 mRNA expression in the mouse cornea occur in response to these three ocular isolates of P. aeruginosa. The data obtained for mRNA expression in the cornea for all three strains of P. aeruginosa correlated well with IL-6 protein analysis of whole-eye homogenates. Differences in the cytokine responses to these strains correlate with differences in the pathology associated with each strain and may offer an opportunity to develop strategies for the improved management of ocular inflammation.


Assuntos
Córnea/imunologia , Interleucina-6/genética , Ceratite/imunologia , Infecções por Pseudomonas/imunologia , Animais , Córnea/metabolismo , Córnea/patologia , Expressão Gênica , Hibridização In Situ , Interleucina-6/biossíntese , Ceratite/genética , Ceratite/patologia , Cinética , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Pseudomonas/genética , Infecções por Pseudomonas/patologia , Pseudomonas aeruginosa/classificação , Pseudomonas aeruginosa/patogenicidade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Especificidade da Espécie
17.
Immunol Cell Biol ; 77(2): 164-6, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10234552

RESUMO

Pseudomonas aeruginosa can cause ulcerative bacterial keratitis or contact lens-induced acute red eye (CLARE) in humans. The present study used a mouse model of ocular infection and inflammation to examine the relationship between TNF-alpha and inflammation in the cornea in response to challenge with either a strain of P. aeruginosa causing keratitis or a CLARE strain. Constitutive TNF-alpha mRNA was detected in the epithelium, mainly towards the periphery. After infection with the keratitis-inducing strain (6294), TNF-alpha expression was elevated four-fold by 24 h post-challenge. No detectable induction of TNF-alpha mRNA was seen with CLARE strain (Paer1) challenge at any time point. The TNF-alpha protein production detected by ELISA showed a corresponding pattern to the mRNA expression, which also correlated with pathological changes. These results suggest that invasive strains of P. aeruginosa create greater pathological changes as a result of elevated TNF-alpha production, which contributes to inflammation during keratitis in vivo.


Assuntos
Córnea/imunologia , Doenças da Córnea/imunologia , Infecções por Pseudomonas/imunologia , Fator de Necrose Tumoral alfa/biossíntese , Animais , Córnea/microbiologia , Doenças da Córnea/microbiologia , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos BALB C , Fator de Necrose Tumoral alfa/genética
18.
Proc Natl Acad Sci U S A ; 95(19): 11412-7, 1998 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-9736750

RESUMO

Dendritic spines are of major importance in information processing and memory formation in central neurons. Estradiol has been shown to induce an increase of dendritic spine density on hippocampal neurons in vivo and in vitro. The neurotrophin brain-derived neurotrophic factor (BDNF) recently has been implicated in neuronal maturation, plasticity, and regulation of GABAergic interneurons. We now demonstrate that estradiol down-regulates BDNF in cultured hippocampal neurons to 40% of control values within 24 hr of exposure. This, in turn, decreases inhibition and increases excitatory tone in pyramidal neurons, leading to a 2-fold increase in dendritic spine density. Exogenous BDNF blocks the effects of estradiol on spine formation, and BDNF depletion with a selective antisense oligonucleotide mimics the effects of estradiol. Addition of BDNF antibodies also increases spine density, and diazepam, which facilitates GABAergic neurotransmission, blocks estradiol-induced spine formation. These observations demonstrate a functional link between estradiol, BDNF as a potent regulator of GABAergic interneurons, and activity-dependent formation of dendritic spines in hippocampal neurons.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/farmacologia , Estradiol/farmacologia , Hipocampo/efeitos dos fármacos , Animais , Células Cultivadas , Dendritos/metabolismo , Diazepam/farmacologia , Regulação para Baixo/efeitos dos fármacos , Eletrofisiologia , Imunofluorescência , Ácido Glutâmico/metabolismo , Hipocampo/embriologia , Microscopia Confocal , Neurônios/metabolismo , Oligonucleotídeos Antissenso/farmacologia , Ratos , Ratos Sprague-Dawley , Transmissão Sináptica/fisiologia , Regulação para Cima/efeitos dos fármacos , Ácido gama-Aminobutírico/metabolismo
20.
Curr Eye Res ; 17(7): 730-5, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9678419

RESUMO

PURPOSE: The present investigation sought to define the responses of mouse eyes to challenge with three different strains of P. aeruginosa isolated from human corneas or contact lenses: two different strains produced an ulcerative keratitis, and one strain produced contact lens-induced acute red eye (CLARE). METHODS: The corneas of BALB/c mice were inoculated with three different strains of P aeruginosa. The strains were allowed to interact with the corneas for up to 24 h. In addition, strain Paerl, isolated from CLARE, was subjected to in vitro assays to measure its ability to invade corneal epithelial cells, or to produce cytotoxicity in these cells. Both these assays used cultured rabbit corneal epithelial cells. RESULTS: Both MK isolates were able to infect the corneas of mice, but the CLARE isolate was non-infective. The predominant response to infection with the cytotoxic strain was severe corneal edema and infiltration of the corneal stroma with polymorphonuclear leukocytes (PMNs). The predominant response with the invasive MK isolate was corneal ulceration and infiltration with PMNs. The CLARE strain produced only low levels of PMN infiltration. In in vitro assays the CLARE strain was non-invasive and non-cytotoxic. CONCLUSIONS: This study has identified that P. aeruginosa produces at least three different types of corneal pathology and that not all strains are able to infect mouse corneas.


Assuntos
Córnea/microbiologia , Córnea/patologia , Infecções Oculares/microbiologia , Infecções por Pseudomonas/patologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/isolamento & purificação , Animais , Células Epiteliais/fisiologia , Células Epiteliais/virologia , Oftalmopatias/microbiologia , Humanos , Inflamação/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Pseudomonas aeruginosa/fisiologia , Coelhos , Especificidade da Espécie
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