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1.
Br J Oral Maxillofac Surg ; 62(5): 504-509, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38685147

RESUMO

Temporomandibular disorders include a wide spectrum of extra-articular and intra-articular conditions affecting the temporomandibular joint (TMJ). In salvage cases involving intra-articular end-stage disease, alloplastic temporomandibular joint replacement (TMJR) is a management option which can be utilised to rehabilitate a disabled joint's function and form. Whilst post-TMJR infection is rare, it is one of the most serious complications. The principles governing TMJR surgery antibiotic prophylaxis have been based on those established in orthopaedic surgery literature. Antibiotic resistance due to antibiotic over-use is a significant concern, therefore antibiotic stewardship has been developed to deal with this world-wide public health concern. The TMJ's anatomical proximity to the external auditory canal and oral cavity creates the potential for bacterial contamination. The aim of this study was to explore the views of 39 sub-specialist TMJ surgeons across nine nations usual approach to antibiotic prophylaxis and their management of TMJR infection. To accomplish this, an international survey was developed and conducted using Google Forms. The results demonstrated that 97.4% of the respondents employ prophylactic antibiotics at TMJR surgery, 83.8% on discharge. Variability in antibiotic choice with additional antimicrobial perioperative practices were also reported. Opinions on the management of a TMJR infection also varied. This survey establishes there is an agreement on the use of antibiotic prophylaxis, However the variability in choice, timing, course, duration of antibiotic use as well as the management of a postoperative TMJR infection demonstrates the need for further study leading to development of standardised antibiotic prophylaxis and infection management protocols for TMJR surgery.


Assuntos
Antibioticoprofilaxia , Artroplastia de Substituição , Transtornos da Articulação Temporomandibular , Articulação Temporomandibular , Humanos , Transtornos da Articulação Temporomandibular/cirurgia , Articulação Temporomandibular/cirurgia , Prótese Articular , Padrões de Prática Médica/estatística & dados numéricos , Inquéritos e Questionários , Antibacterianos/uso terapêutico , Infecção da Ferida Cirúrgica/prevenção & controle
2.
Br Dent J ; 233(4): 245-246, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-36028665
3.
Org Biomol Chem ; 14(35): 8253-60, 2016 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-27519121

RESUMO

A new antibiotic natural product, ravynic acid, has been isolated from a Penicillium sp. of fungus, collected from Ravensbourne National Park. The 3-acylpolyenyne tetramic acid structure was definitively elucidated via synthesis. Highlights of the synthetic method include the heat induced formation of the 3-acylphosphorane tetramic acid and a selective Wittig cross-coupling to efficiently prepare the natural compounds carbon skeleton. The natural compound was shown to inhibit the growth of Staphylococcus aureus down to concentrations of 2.5 µg mL(-1).


Assuntos
Antibacterianos/síntese química , Penicillium/química , Pirrolidinonas/síntese química , Alcinos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Humanos , Fosforanos/síntese química , Propanóis/química , Pirrolidinonas/química , Pirrolidinonas/isolamento & purificação , Pirrolidinonas/farmacologia , Staphylococcus aureus/efeitos dos fármacos
4.
Proc Natl Acad Sci U S A ; 106(22): 8877-82, 2009 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-19470640

RESUMO

Orchids employing sexual deceit attract males of their pollinator species through specific volatile signals that mimic female-released sex pheromones. One of these signals proved to be 2-ethyl-5-propylcyclohexan-1,3-dione (chiloglottone1), a new natural product that was shown to be most important in the relations between orchids of the genus Chiloglottis, native to Australia, and corresponding pollinator species. Systematic investigations on the mass spectrometric fragmentation pattern of 2,5-dialkylcyclohexan-1,3-diones identified key ions providing information about the structures of the substituents at positions 2 and 5. Results enabled us to identify 2-ethyl-5-pentylcyclohexan-1,3-dione (chiloglottone2) and 2-butyl-5-methylcyclohexan-1,3-dione (chiloglottone3) as new natural products that play a decisive role in the pollination syndrome of some Chiloglottis species. During field bioassays, pure synthetic samples of chiloglottone1-3 or mixtures thereof proved to be attractive to the corresponding orchid pollinators. Because of their likely biogenesis from ubiquitous fatty acid precursors, 2,5-dialkylcyclohexan-1,3-diones may represent a hitherto overlooked, widespread class of natural products.


Assuntos
Produtos Biológicos/química , Cicloexanonas/química , Orchidaceae/química , Atrativos Sexuais/química , Produtos Biológicos/metabolismo , Cicloexanonas/metabolismo , Espectroscopia de Ressonância Magnética , Orchidaceae/metabolismo , Atrativos Sexuais/metabolismo
5.
Mini Rev Med Chem ; 9(3): 273-92, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19275720

RESUMO

The linear naphtho-gamma-pyrone (LNGP) moiety is a naturally occurring scaffold with broad biological activity ranging through antimicrobial, antiviral, insecticidal and anti-estrogenic activity. This review, the first of its kind, surveys the chemical literature in an effort directed toward assembling data that will facilitate the construction of activity profiles associated with this emerging class of compounds. The structural and associated biological information has been presented in tabular format with all structures revealed throughout the document and referencing that will allow the reader to rapidly access the literature pertaining to a specific activity or structural class.


Assuntos
Naftalenos/química , Naftalenos/farmacologia , Pironas/química , Pironas/farmacologia , Animais , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/toxicidade , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/toxicidade , Moduladores de Receptor Estrogênico/química , Moduladores de Receptor Estrogênico/farmacologia , Moduladores de Receptor Estrogênico/toxicidade , Humanos , Estrutura Molecular , Naftalenos/toxicidade , Praguicidas/química , Praguicidas/farmacologia , Praguicidas/toxicidade , Pironas/toxicidade , Relação Estrutura-Atividade
6.
J Thromb Haemost ; 7(4): 658-64, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19187078

RESUMO

OBJECTIVE: The pathogenicity of anti-human factor (F) VIII monoclonal antibodies (MAbs) was tested in a murine bleeding model. METHODS: MAbs were injected into the tail veins of hemophilia A mice to a peak plasma concentration of 60 nm, followed by injection of human B domain-deleted FVIII at 180 U kg(-1), producing peak plasma concentrations of approximately 2 nm. At 2 h, blood loss following a 4-mm tail snip was measured. The following MAbs were tested: (i) 4A4, a type I anti-A2 FVIII inhibitor, (ii) I54 and 1B5, classical type I anti-C2 inhibitors, (iii) 2-77 and B45, non-classical type II anti-C2 inhibitors, and (iv) 2-117, a non-classical anti-C2 MAb with inhibitory activity less than 0.4 Bethesda Units per mg IgG. RESULTS: All MAbs except 2-117 produced similar amounts of blood loss that were significantly greater than control mice injected with FVIII alone. Increasing the dose of FVIII to 360 U kg(-1) overcame the bleeding diathesis produced by the type II MAbs 2-77 and B45, but not the type I antibodies, 4A4, I54, and 1B5. These results were consistent with the in vitro Bethesda assay in which 4A4 completely inhibited both 1 U mL(-1) and 3 U mL(-1) FVIII, while there was 40% residual activity at saturating concentrations of 2-77 at either concentration of FVIII. CONCLUSIONS: For patients with an inhibitor response dominated by non-classical anti-C2 antibodies both the in vivo and in vitro results suggest that treatment with high-dose FVIII rather than bypassing agents may be warranted.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Epitopos/imunologia , Fator VIII/imunologia , Hemofilia A/imunologia , Hemorragia/imunologia , Animais , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/sangue , Modelos Animais de Doenças , Fator VIII/administração & dosagem , Humanos , Camundongos
7.
Int Immunopharmacol ; 7(4): 515-23, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17321475

RESUMO

Gavage of mice, immunised with an inactivated S. typhimurium vaccine, with Andrographis paniculata extract [APE] or andrographolide [AND] resulted in an enhancement of Salmonella-specific antibody response and induction of cell-mediated response against salmonellosis. Mice were vaccinated with either one or two doses of killed S. typhimurium vaccine and fed two different quantities of APE or AND, for 14 days in mice immunised with one dose of the vaccine, and for 28 days in mice immunised with two doses of vaccine, respectively. Both APE and AND were found to enhance IgG antibody levels against S. typhimurium, the enhancement being statistically significant in mice receiving two doses of the vaccine. Splenocyte cultures, prepared from mice immunised with the killed Salmonella vaccine and treated with APE or AND, showed a remarkable increase in the production IFN-gamma following stimulation with the bacterial lysate, indicating an induction of Salmonella-specific cell-mediated response/immune response.


Assuntos
Andrographis/química , Diterpenos/farmacologia , Fatores Imunológicos/farmacologia , Vacinas contra Salmonella , Salmonella typhimurium/imunologia , Animais , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Feminino , Imunização , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Interferon gama/biossíntese , Interferon gama/imunologia , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/farmacologia , Baço/citologia , Baço/efeitos dos fármacos , Baço/imunologia , Vacinas de Produtos Inativados
8.
J Thromb Haemost ; 5(3): 512-9, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17181826

RESUMO

BACKGROUND: Inhibitory antibodies (Abs) to factor VIII (FVIII inhibitors) constitute the most significant complication in the management of hemophilia A. The analysis of FVIII inhibitors is confounded by polyclonality and the size of FVIII. OBJECTIVES: The goal of this study was to dissect the polyclonal response to human FVIII in hemophilia A mice undergoing a dosage schedule that mimics human use. METHODS: Splenic B-cell hybridomas were obtained following serial i.v. injections of submicrogram doses of FVIII. Results of a novel, anti-FVIII domain-specific enzyme-linked immunosorbent assay were compared to Ab isotype and anti-FVIII inhibitory activity. RESULTS: The robust immune response resulted in the production of approximately 300 hybridomas per spleen. We characterized Abs from 506 hybridomas, representing the most comprehensive analysis of a protein antigen to date. Similar to the human response to FVIII, anti-A2 and anti-C2 Abs constituted the majority of inhibitors. A novel epitope was identified in the A2 domain by competition ELISA. Anti-A2 and anti-C2 Abs were significantly associated with IgG(1) and IgG(2a) isotypes, respectively. Because the IgG(2a) isotype is associated with enhanced Fc receptor-mediated effector mechanisms, this result suggests that anti-C2 Abs and inflammation may be linked. Additionally, we identified a novel class of Abs with dual specificity for the A1 and A3 domains. Forty per cent of the Abs had no detectable inhibitory activity, indicating that they are prominent and potentially pathologically significant. CONCLUSION: The expanded delineation of the humoral response to FVIII may lead to improved management of hemophilia A through mutagenesis of FVIII B-cell epitopes.


Assuntos
Anticorpos Monoclonais/imunologia , Formação de Anticorpos , Coagulantes/imunologia , Fator VIII/imunologia , Hemofilia A/imunologia , Isotipos de Imunoglobulinas/imunologia , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/sangue , Especificidade de Anticorpos , Sítios de Ligação de Anticorpos , Ligação Competitiva , Linhagem Celular , Coagulantes/administração & dosagem , Cricetinae , Modelos Animais de Doenças , Esquema de Medicação , Ensaio de Imunoadsorção Enzimática/métodos , Mapeamento de Epitopos/métodos , Fator VIII/administração & dosagem , Fator VIII/genética , Fator VIII/metabolismo , Hemofilia A/sangue , Hemofilia A/tratamento farmacológico , Humanos , Hibridomas/metabolismo , Isotipos de Imunoglobulinas/biossíntese , Isotipos de Imunoglobulinas/sangue , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Recombinantes de Fusão/imunologia , Reprodutibilidade dos Testes , Baço/citologia , Baço/metabolismo , Suínos , Transfecção
9.
J Thromb Haemost ; 4(10): 2223-9, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16856973

RESUMO

BACKGROUND: Inhibitory antibodies to factor (F) VIII (FVIII inhibitors) present a major clinical challenge as a complication of hemophilia A and as acquired autoantibodies in non-hemophiliacs. Porcine FVIII is a potentially useful therapeutic agent because of its low crossreactivity with many inhibitors. Recombinant porcine FVIII (rpFVIII) is undergoing clinical trials in inhibitor patients. OBJECTIVES: The goals of this study were to neutralize human FVIII inhibitors in vitro with rpFVIII and to characterize the relationship between recovery of FVIII activity and the antiporcine FVIII inhibitor titer. METHODS: rpFVIII was added to 28 antihuman FVIII inhibitor plasmas and assayed either immediately or after a 2 h preincubation at 37 degrees C. The concentration of rpFVIII required for recovery of FVIII activity to 50% of normal (EC(50)) was determined by polynomial regression analysis and compared with the antiporcine FVIII inhibitor titer measured by Bethesda assay. RESULTS: Six of nine plasmas classified as non-crossreactive by Bethesda assay had detectable inhibitory activity in the FVIII recovery assay. Recovery was decreased following a 2 h preincubation compared with immediate assay for the 19 plasmas with detectable antiporcine FVIII inhibitors. There was a linear relationship between EC(50) and inhibitor titer for plasmas with antiporcine FVIII titers ranging from 0.6 to 10 BU per milliliter in both the immediate and the 2 h preincubation assays. CONCLUSION: A quantitative method for analysis of inhibitor neutralization in vitro has been developed, which may be useful for comparison with pharmacodynamic studies of rpFVIII in FVIII inhibitor patients and subsequent rational dosing in this patient population.


Assuntos
Fator VIII/química , Hemofilia A/terapia , Proteínas Recombinantes/química , Animais , Fatores de Coagulação Sanguínea/química , Testes de Coagulação Sanguínea , Química Clínica/métodos , Fator VIII/antagonistas & inibidores , Hemofilia A/sangue , Humanos , Concentração de Íons de Hidrogênio , Suínos , Temperatura , Fatores de Tempo
10.
Burns ; 30(6): 565-8, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15302422

RESUMO

Hepatomegaly is a common finding at autopsy in severely burned children surviving less than 6 months. This study validates a reliable ultrasound method which can be used to identify changes in liver size in severely burned children during acute hospitalization. Thirty-eight children, age 0.5-17 years with burns covering over 40% of their total surface area were studied at autopsy. Liver weight was measured at autopsy and compared to predicted liver weight for age and height. Eighteen had liver size measured by ultrasound within 10 days of death while five had ultrasound liver measures after death just prior to autopsy. All burned children who survived 7 days or more (n = 33) had liver weights at autopsy that were greater than predicted for age and height while all 23 livers measured by ultrasound were greater than predicted. Autopsy weights correlated well with weights estimated by ultrasound, R = 0.824. At autopsy, those who survived 7 days or more had enlarged livers ranging from 142 to 406% of their predicted normal age and height. Common histologic findings include large and small-droplet fat deposits, and cholestasis. The degree of these histologic abnormalities correlated with the increase in liver weight, R = 0.652. Ultrasound is a valid, noninvasive method for measuring liver weight changes in severely burned children during acute hospitalization. Ninety-five percent of the severely burned children from this institute had significant hepatomegaly identified at autopsy.


Assuntos
Queimaduras/diagnóstico por imagem , Fígado/diagnóstico por imagem , Adolescente , Autopsia , Superfície Corporal , Queimaduras/mortalidade , Queimaduras/patologia , Criança , Pré-Escolar , Feminino , Hepatomegalia/diagnóstico por imagem , Hepatomegalia/patologia , Humanos , Lactente , Fígado/patologia , Masculino , Tamanho do Órgão/fisiologia , Ultrassonografia
11.
J Clin Pathol ; 57(8): 849-55, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15280407

RESUMO

BACKGROUND: Congenital neomelanocytic naevi appear in nearly 1% of newborns. Giant hairy naevi (GHN) are uncommon lesions covering large areas of the body. They are of concern because they have the potential to transform into malignant melanomas. AIMS: To describe gene expression profiles of GHN and nearby normal skin from patients with GHN and normal control skin (from patients with cleft lip/palate). METHODS: Tissues from three patients with GHN and two normal controls were studied for differences in gene expression profiles. Total RNA was isolated from normal skin near the hairy naevus, GHN, and skin from normal controls. The RNA samples were subjected to probe labelling, hybridisation to chips, and image acquisition according to the standard Affymetrix protocol. RESULTS: There were 227 genes affected across all samples, as determined by DNA microarray analysis. There was increased expression of 22 genes in GHN compared with nearby normal skin. Decreased expression was noted in 73 genes. In addition, there was increased expression of 36 genes in normal skin near GHN compared with normal control skin, and decreased expression of five genes. Categories of genes affected were those encoding structural proteins, proteins related to developmental processes, cell death associated proteins, transcription factors, growth factors, stress response modulators, and collagen associated proteins. Changes in mRNA expression were checked by reverse transcription polymerase chain reaction. CONCLUSIONS: Genetic profiles of GHN may provide insight into their pathogenesis, including their potential for malignant transformation. Such information may be useful in improving the understanding and management of these lesions.


Assuntos
Nevo Pigmentado/genética , Neoplasias Cutâneas/genética , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Perfilação da Expressão Gênica , Humanos , Masculino , Nevo Pigmentado/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Pele/metabolismo , Neoplasias Cutâneas/patologia
12.
J Thromb Haemost ; 2(4): 605-11, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15102015

RESUMO

Hyate is a commercial plasma-derived porcine factor (F)VIII concentrate that is used in the treatment of patients with inhibitory antibodies to FVIII. OBI-1 is a recombinant B domain-deleted form of porcine FVIII that is in clinical development for the same indication. Hemophilia A mice were presensitized with human FVIII to simulate clinical inhibitory antibody formation and then were randomized to receive OBI-1 or Hyate:C in a comparative immunogenicity trial. OBI-1 or Hyate:C were given in a series of four intravenous injections at weekly intervals at doses of 1, 10, or 100 U kg(-1). Inhibitory antibodies to porcine FVIII were not detected by Bethesda assay in most of the mice given OBI-1 or Hyate:C at doses of 1 or 10 U kg(-1), but were identified in 81% and 94% of mice given 100 U kg(-1) of OBI-1 or Hyate:C, respectively. There was no significant difference between OBI-1 and Hyate:C in inhibitory antibody formation at any dose, although there was a trend toward a lower Bethesda titer in OBI-1-treated mice at 10 U kg(-1) (P = 0.09). Total anti-FVIII antibodies to Hyate:C and OBI-1 were also measured by ELISA using immobilized purified plasma-derived porcine FVIII and OBI-1, respectively, as antigens. At the 10 and 100 U kg(-1) doses, the mean anti-FVIII response was higher in Hyate:C-treated-mice than in OBI-1-treated mice (P = 0.02 and P = 0.004, respectively). The results using this model suggest that OBI-1 may be less immunogenic and safer than Hyate:C in FVIII inhibitor patients.


Assuntos
Formação de Anticorpos/efeitos dos fármacos , Fator VIII/imunologia , Hemofilia A/tratamento farmacológico , Fragmentos de Peptídeos/imunologia , Animais , Anticorpos Heterófilos/sangue , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Fator VIII/uso terapêutico , Hemofilia A/imunologia , Humanos , Camundongos , Camundongos Knockout , Fragmentos de Peptídeos/uso terapêutico , Suínos
13.
Arch Surg ; 136(11): 1301-6, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11695977

RESUMO

HYPOTHESIS: Characteristic of the hypermetabolic response to a thermal injury is the massive protein catabolism and compromised structure and function of essential organs. Nutrition has been suggested to affect protein metabolism and clinical outcome after a severe injury but published studies show controversial data. The purpose of this study was to determine the effect of enriched nutritional support during the postburn hypermetabolic state on protein metabolism in serum, liver, muscle, and skin. SETTING: Laboratory. INTERVENTION: Twenty-two rats were given burns covering 60% of their total body surface area and randomized to receive either standard rat chow (control) or a diet high in vitamins, protein, amino acids, and omega3 fatty acids. MAIN OUTCOME MEASURES: Five weeks after injury, body weight, serum, muscle, and hepatic protein content, insulin-like growth factor I concentration, and wound healing (reepithelization) were determined. RESULTS: Rats receiving the enriched diet showed a gradual improvement in body weight 1, 2, 3, 4, and 5 weeks postburn compared with controls (P< .001). Diet-fed rats demonstrated higher protein and insulin-like growth factor 1 content in serum, muscle, and liver 5 weeks after trauma (P< .001). Serum protein, albumin, and transferrin levels were significantly increased in rats receiving the diet compared with control rats (P< .001). Reepithelization was accelerated in rats receiving the enriched diet 4 (diet-fed, mean +/- SD, 23% +/- 1% vs controls, 17% +/- 1%; P< .001) and 5 (diet-fed, 24% +/- 1% vs controls, 18% +/- 1%; P< .001) weeks postburn compared with control rats. CONCLUSIONS: Nutritional intervention high in protein, vitamins, amino acids, and omega3 fatty acids improves protein net balance during the hypermetabolic response to thermal injury. Compromised organ function and structure and clinical outcome during the hypermetabolic response may be improved.


Assuntos
Queimaduras/metabolismo , Queimaduras/terapia , Alimentos Fortificados , Fenômenos Fisiológicos da Nutrição , Proteínas/metabolismo , Animais , Fator de Crescimento Insulin-Like I/análise , Fígado/química , Masculino , Músculo Esquelético/química , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Cicatrização
14.
Shock ; 16(5): 373-9, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11699076

RESUMO

After a severe trauma, such as a cutaneous thermal injury, an increase in hepatocyte apoptosis has been associated with hepatocyte damage and impairment in hepatic function. Insulinlike growth factor-I (IGF-I) exerts antiapoptotic effects in several organs, thus improving organ homeostasis. The purpose of the present study was to determine whether IGF-I in combination with its principle binding protein-3 (BP-3) attenuates liver damage after a burn and whether this attenuation is through signals of the apoptotic-proliferative axis of hepatocytes. Sprague-Dawley rats (56 males) received a 60% total body surface area third-degree scald burn and were randomly divided to receive either rhlGF-I/BP3 (10 mg/kg/day s.c.) or saline (control). Serum aspartate transaminase (AST) and nitric oxide (NO), and hepatocyte proliferation and apoptosis, were measured on postburn days 1, 2, 5, and 7. Hepatic interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) mRNA and hepatic nuclear-factor kappa B (NF-kappa B) were determined at 1 and 2 days postburn. IGF-I/BP-3 decreased serum AST and increased serum NO at 1, 2, and 5 days after burn when compared with controls (P < 0.05). IGF-I/BP-3 increased hepatocyte proliferation on the first day after burn and decreased hepatocyte apoptosis at day 7 postburn when compared with controls (P < 0.05). IGF-I/BP-3 decreased hepatic IL-1 beta and TNF-alpha mRNA 1 day after burn (P < 0.05). IGF-I/BP-3 further increased hepatic NF-kappa B concentration 1 and 2 days postburn when compared with controls (P < 0.05). Recombinant hIGF-I in combination with its principle binding protein conserves hepatic homeostasis, which is associated with a transient increase in hepatocyte proliferation and decrease in hepatocyte apoptosis possibly through NO and hepatic NF-kappa B.


Assuntos
Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Fígado/lesões , Fígado/metabolismo , Ferimentos e Lesões/metabolismo , Animais , Apoptose , Aspartato Aminotransferases , Queimaduras/patologia , Queimaduras/fisiopatologia , Divisão Celular/efeitos dos fármacos , Hepatócitos/patologia , Homeostase/efeitos dos fármacos , Marcação In Situ das Extremidades Cortadas , Fígado/patologia , Masculino , NF-kappa B/metabolismo , Óxido Nítrico/sangue , Ratos , Ratos Sprague-Dawley
15.
Shock ; 16(5): 380-2, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11699077

RESUMO

A severe thermal injury is commonly associated with immune suppression and increased susceptibility to sepsis, frequently leading to multiple organ failure. Transforming growth factor-beta (TGF-beta) is a potent immunosuppressive cytokine involved in complications associated with major trauma. Interleukin- 4 (IL-4) is thought to synergize the immunosuppressive activity of TGF-beta by promoting naive lymphocytes to differentiate and generate TGF-beta secreting cells. This study examines the alterations in serum levels of TGF-beta and IL-4 after a thermal injury. Male Sprague-Dawley rats (300-400 g) were anesthetized and received a 50% total body surface area full-thickness scald burn followed by fluid resuscitation and analgesia. Control rats were given the same treatment, but were immersed in water at room temperature. Rats were sacrificed from 1 h to 8 days after injury. Blood samples were collected aseptically from the inferior caval vein. Serum levels of TGF-beta and IL-4 were measured by enzyme linked immunosorbent assay. Rats in the control and thermal injury groups showed similar increases in serum TGF-beta 1 h after injury. A progressive increase in serum TGF-beta was observed in burned animals compared to control animals starting on day 3 and continued through day 8 (P < 0.01). Serum IL-4 levels in control and thermally injured animals remained undetectable (< 15.6 pg/mL) throughout the experiment. Thermal injury induces a significant increase in serum TGF-beta, which may contribute to post-burn immunosuppression with an increased susceptibility to sepsis.


Assuntos
Queimaduras/sangue , Fator de Crescimento Transformador beta/sangue , Animais , Biomarcadores/sangue , Ensaio de Imunoadsorção Enzimática , Masculino , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
16.
Gene Ther ; 8(18): 1409-15, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11571581

RESUMO

The use of systemic IGF-1 has been shown to attenuate the postburn hypermetabolic response and improve burn wound healing. Local IGF-1 gene therapy, however, promotes re-epithelialization in the burn wound without the side-effects associated with systemic delivery. We tested the hypothesis that these beneficial effects are due to changes in local cytokine production. Adult male Sprague-Dawley rats received a 40% total body surface area full-thickness scald burn and randomly received a subcutaneous injection at the burn wound margin of saline or cationic liposomes containing a IGF-1 cDNA construct. Animals were killed at 1, 4, 7 and 10 days after burn trauma. Skin biopsies at the wound border were harvested for total RNA extraction. Cytokine mRNA expression was determined using a multi-probe RNase protection assay. Data are presented as means +/- s.e.m. Statistical analysis used the unpaired t-test or Mann-Whitney test where appropriate. Significance was accepted at P < 0.05. Treatment of the burn wound with liposomal IGF-1-cDNA transfer decreased IL-1beta mRNA levels on day 10 after burn trauma from five-fold burn-induced increases compared with sham-treated rats, to near the control values present in unburned skin samples. Similarly, there was an eight-fold increase in TNF-alpha mRNA expression on postburn day 10 that was abrogated by IGF-1 gene therapy. Local IGF-1 gene transfer attenuates the mRNA expression of the inflammatory cytokines IL-1beta and TNF-alpha in the burn wound. This change may improve burn wound healing by decreasing prolonged local inflammation.


Assuntos
Queimaduras/terapia , Citocinas/genética , Terapia Genética/métodos , Fator de Crescimento Insulin-Like I/genética , RNA Mensageiro/metabolismo , Animais , Expressão Gênica , Injeções Subcutâneas , Interleucina-1/genética , Lipossomos , Masculino , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Estatísticas não Paramétricas , Fator de Necrose Tumoral alfa/genética
18.
Crit Care Med ; 29(7): 1417-22, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11445701

RESUMO

OBJECTIVE: To investigate the effect of a thermal injury on pulmonary surfactant phosphatidylcholine kinetics. DESIGN: Random, controlled study. SETTING: University research laboratory. SUBJECTS: Yorkshire swine (n = 8) with and without a 40% total body surface area burn. INTERVENTIONS: A new isotope tracer methodology was used to quantify surfactant phosphatidylcholine kinetics. Four days after burn, [1,2-13C2]acetate and [U-(13)C16]palmitate were infused continuously for 8 hrs to quantify surfactant phosphatidylcholine synthesis, secretion, recycling, and irreversible loss. MEASUREMENTS AND MAIN RESULTS: The total surfactant phosphatidylcholine pool size was reduced from the control value of 2.65 +/- 0.05 to 1.61 +/- 0.08 micromol/g wet lung in burned animals (p <.05), as was the proportional contribution of palmitate to lung surfactant phosphatidylcholine composition. This reduction was associated with a significant decrease in lung dynamic compliance from the control value of 66 +/- 6 to 55 +/- 6 mL/cm H2O for burned pigs (p <.05). The most prominent response of lung phosphatidylcholine kinetics was a decrease in the total lung phosphatidylcholine synthesis from a control value of 12.7 +/- 1.2 to 5.5 +/- 0.3 nmol phosphatidylcholine-bound palmitate x hr(-1) x g of wet lung(-1) in burned animals (p<.05). CONCLUSIONS: Pulmonary phosphatidylcholine content and palmitate composition decrease after burn injury because of a decrease in the rate of phosphatidylcholine synthesis. These responses likely contribute to impaired lung compliance.


Assuntos
Queimaduras/fisiopatologia , Pulmão/metabolismo , Fosfatidilcolinas/metabolismo , Surfactantes Pulmonares/metabolismo , Síndrome do Desconforto Respiratório/fisiopatologia , Animais , Isótopos de Carbono , Ácidos Graxos/sangue , Hemodinâmica , Marcação por Isótopo/métodos , Pulmão/patologia , Complacência Pulmonar , Surfactantes Pulmonares/química , Distribuição Aleatória , Suínos , Urânio
19.
J Chem Ecol ; 27(4): 747-60, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11446298

RESUMO

A screening was conducted to study the allelopathic potential of Australian-held accessions of Triticum speltoides. Of 26 accessions, four were found to inhibit root growth in the indicator species, lettuce (Lactuca sativa). The methanol leaf extracts of these accessions significantly reduced the root length of wild oat (Avena spp.). In all but one case, alellopathic accessions contained higher amounts of DIMBOA than did nonallelopathic accessions. Since some variation in allelopathic response was detected within lines, random amplified polymorphic DNA (RAPD) markers were used to estimate genetic diversity between and within the allelopathic accessions of Triticum speltoides L. The average genetic similarity between all possible pairs of selected accessions was found to be 55% and ranged from 44% to 88%. Comparison of DNA extracted from different single seedlings within the same accession revealed significant intraaccession genetic diversity (4-24%), although this was much less than that observed between accessions tested. This intraaccession diversity has significant implications for the selection of T. speltoides accessions in breeding or screening programs.


Assuntos
DNA de Plantas/análise , Oxazinas/farmacologia , Triticum/genética , Triticum/fisiologia , Benzoxazinas , Variação Genética , Lactuca/crescimento & desenvolvimento , Oxazinas/análise , Controle de Pragas , Técnica de Amplificação ao Acaso de DNA Polimórfico , Seleção Genética
20.
Burns ; 27(5): 447-52, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11451596

RESUMO

Delays in growth are commonly observed in children who have sustained a severe cutaneous burn. The reasons for this growth delay are not completely known, but in adults, plasma growth hormone (GH) levels have been shown to decrease after thermal injury. If this is also the case in severely burned children, the low GH levels may contribute to their chronic growth delay. We propose that treatment with rhGH may prevent this burn-induced growth delay. Height velocities were measured for up to 2 years after injury in 38 burned children (age 7+/-1 years) with a 64+/-2% total burn surface area (TBSA) burn and a 59+/-3% third-degree burn who received 0.2 mg/kg/day rhGH during hospitalization. These height velocities were compared to 41 burned children (age 8+/-1 years) with a 64+/-3% TBSA burn and a 60+/-3% TBSA third-degree burn who were treated similarly but did not receive rhGH. Height velocities and height percentiles were compared to standard height velocity and percentile nomograms of unburned children. To determine the effect of rhGH on energy requirements, resting energy expenditures (REE) were measured by indirect calorimetry and compared to values calculated from the Harris-Benedict equation. All data are presented as mean+/-S.E.M. No differences in average height percentile could be shown between those receiving GH and controls at admission and 6 months after burn. There was, however, a significant difference (P<0.05) in height velocity during the first 2 years after burn between GH (47th+/-6 percentile) and controls (32nd+/-5 percentile). For rhGH-treated children, the REE was elevated by 34+/-4% versus 35+/-5% for controls. Recombinant human GH, given during acute hospitalization, maintained growth in severely burned children who would otherwise experience a significant growth delay. Treatment with rhGH did not atttenuate their elevated REE.


Assuntos
Estatura/efeitos dos fármacos , Queimaduras/tratamento farmacológico , Queimaduras/fisiopatologia , Metabolismo Energético/efeitos dos fármacos , Hormônio do Crescimento Humano/administração & dosagem , Adolescente , Queimaduras/diagnóstico , Criança , Desenvolvimento Infantil/fisiologia , Pré-Escolar , Esquema de Medicação , Feminino , Seguimentos , Humanos , Injeções Subcutâneas , Escala de Gravidade do Ferimento , Masculino , Probabilidade , Valores de Referência , Estatísticas não Paramétricas , Resultado do Tratamento
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