Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
1.
Nat Ecol Evol ; 6(11): 1710-1722, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36163257

RESUMO

Protecting nature's contributions to people requires accelerating extinction risk assessment and better integrating evolutionary, functional and used diversity with conservation planning. Here, we report machine learning extinction risk predictions for 1,381 palm species (Arecaceae), a plant family of high socio-economic and ecological importance. We integrate these predictions with published assessments for 508 species (covering 75% of all palm species) and we identify top-priority regions for palm conservation on the basis of their proportion of threatened evolutionarily distinct, functionally distinct and used species. Finally, we explore palm use resilience to identify non-threatened species that could potentially serve as substitutes for threatened used species by providing similar products. We estimate that over a thousand palms (56%) are probably threatened, including 185 species with documented uses. Some regions (New Guinea, Vanuatu and Vietnam) emerge as top ten priorities for conservation only after incorporating machine learning extinction risk predictions. Potential substitutes are identified for 91% of the threatened used species and regional use resilience increases with total palm richness. However, 16 threatened used species lack potential substitutes and 30 regions lack substitutes for at least one of their threatened used palm species. Overall, we show that hundreds of species of this keystone family face extinction, some of them probably irreplaceable, at least locally. This highlights the need for urgent actions to avoid major repercussions on palm-associated ecosystem processes and human livelihoods in the coming decades.


Assuntos
Arecaceae , Ecossistema , Animais , Humanos , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Plantas
2.
J Mater Sci Mater Med ; 24(4): 1113-22, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23371769

RESUMO

During its tenure in vivo, synthetic mesh materials are exposed to foreign body responses, which can alter physicochemical properties of the material. Three different synthetic meshes comprised of polypropylene, expanded polytetrafluoroethylene (ePTFE), and polyethylene terephthalate (PET) materials were explanted from a single patient providing an opportunity to compare physicochemical changes between three different mesh materials in the same host. Results from infrared spectroscopy demonstrated significant oxidation in polypropylene mesh while ePTFE and PET showed slight chemical changes that may be caused by adherent scar tissue. Differential scanning calorimetry results showed a significant decrease in the heat of enthalpy and melt temperature in the polypropylene mesh while the ePTFE and PET showed little change. The presence of giant cells and plasma cells surrounding the ePTFE and PET were indicative of an active foreign body response. Scanning electron micrographs and photo micrographs displayed tissue entrapment and distortion of all three mesh materials.


Assuntos
Hérnia Abdominal/cirurgia , Polietilenotereftalatos/química , Polipropilenos/química , Politetrafluoretileno/química , Humanos , Masculino , Pessoa de Meia-Idade , Espectrofotometria Infravermelho , Telas Cirúrgicas
3.
J Biomed Mater Res A ; 101(10): 2778-87, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23436761

RESUMO

The extracellular matrices of a variety of human and animal tissues have been utilized as scaffold materials for soft tissue applications including hernia repair, dermal grafts, and tendon, ligament, and cartilage reconstruction. While these biological scaffolds are expected to demonstrate superior tissue integration, there is very little evidence documenting the properties and behavior of these materials in vivo. This in vivo study investigated four biological scaffolds: two commercially available (a moderately crosslinked scaffold and a noncrosslinked scaffold) and two novel porcine diaphragm biological scaffolds (one with and one without the incorporation of gold nanoparticles). The scaffolds were implanted in a porcine model and evaluated over 1, 3, and 6 months. The moderately crosslinked scaffolds demonstrated the least cellular infiltration and evidence of fibrosis. The noncrosslinked scaffolds demonstrated the greatest cellular infiltration, but these scaffolds were delaminated and exhibited a rapid loss of integrity. The porcine diaphragm scaffolds with and without nanoparticles showed evidence of tissue remodeling and cellular infiltration, with no evidence of encapsulation. While there were no significant differences in the performance of the two novel scaffolds, the gold nanoparticle scaffold typically exhibited higher cellular infiltration. This study demonstrated the potential biocompatibility of a gold nanoparticle-tissue scaffold.


Assuntos
Ouro/farmacologia , Nanopartículas Metálicas/química , Alicerces Teciduais/química , Animais , Tecido Conjuntivo/efeitos dos fármacos , Tecido Conjuntivo/patologia , Feminino , Células Gigantes/efeitos dos fármacos , Células Gigantes/patologia , Humanos , Modelos Animais , Neovascularização Fisiológica/efeitos dos fármacos , Sus scrofa , Fatores de Tempo
4.
Hernia ; 17(2): 193-202, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22648066

RESUMO

PURPOSE: Although situational risk factors for incisional hernia formation are known, the methods used to determine who would be most susceptible to develop one are unreliable. We hypothesized that patients with recurrent incisional hernias may possess unique gene expression profiles. METHODS: Skin and intact fascia were collected from 15 normal control (NC) patients with no hernia history and 18 patients presenting for recurrent incisional hernia (RH) repair. Microarray analysis was performed using whole genome microarray chips on NC (n = 8) and RH (n = 9). These samples were further investigated using a pathway-specific PCR array containing fibrosis-related genes. RESULTS: Microarray data revealed distinct differences in the gene expression profiles between RH and NC patients. One hundred and sixty-seven genes in the skin and 7 genes in the fascia were differentially expressed, including 8 directly involved in collagen synthesis. In particular, GREMLIN1, or bone morphogenetic protein antagonist 1, was under expressed in skin (fold = 0.49, p < 10(-7), q = 0.0009) and fascia (fold = 0.23, p < 10(-4), q = 0.095) of RH patients compared with NC. The PCR array data supported previous reports of decreased collagen I/III ratios in skin of RH versus NC (mean = 1.51 ± 0.73 vs. mean = 2.26 ± 0.99; one-sided t test, p = 0.058). CONCLUSION: To our knowledge, this is the first microarray-based analysis to show distinct gene expression profiles between the skin and fascia of RH and NC patients and the first report of an association between GREMLIN1 and incisional hernia formation. Our results suggest that gene expression profiles may act as surrogate markers that stratify patients into different groups at risk for hernia development prior to their initial surgery.


Assuntos
Perfilação da Expressão Gênica , Adulto , Colágeno/biossíntese , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Fáscia/metabolismo , Feminino , Predisposição Genética para Doença , Hérnia Ventral , Humanos , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Análise em Microsséries , Pessoa de Meia-Idade , Recidiva , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Medição de Risco , Fatores de Risco , Cicatrização/genética
5.
J Mater Sci Mater Med ; 22(12): 2803-12, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21979166

RESUMO

Polypropylene mesh materials have been utilized in hernia surgery for over 40 years. However, they are prone to degradation due to the body's aggressive foreign body reaction, which may cause pain or complications, forcing mesh removal from the patient. To mitigate these complications, gold nanomaterials were attached to polypropylene mesh in order to improve cellular response. Pristine samples of polypropylene mesh were exposed to hydrogen peroxide/cobalt chloride solutions to induce formation of surface carboxyl functional groups. Gold nanoparticles were covalently linked to the mesh. Scanning electron microscopy confirmed the presence of gold nanoparticles. Differential scanning calorimetry and mechanical testing confirmed that the polypropylene did not undergo any significantly detrimental changes in physicochemical properties. A WST-1 cell culture study showed an increase in cellularity on the gold nanoparticle-polypropylene mesh as compared to pristine mesh. This study showed that biocompatibility of polypropylene mesh may be improved via the conjugation of gold nanoparticles.


Assuntos
Alcenos/química , Materiais Biocompatíveis/química , Ouro/química , Nanopartículas Metálicas/química , Polipropilenos/química , Telas Cirúrgicas , Aminas/química , Animais , Varredura Diferencial de Calorimetria , Linhagem Celular , Cobalto/química , Reagentes de Ligações Cruzadas/química , Reação a Corpo Estranho , Hérnia/terapia , Peróxido de Hidrogênio/química , Teste de Materiais , Camundongos , Microscopia Eletrônica de Varredura , Nanotecnologia , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Mecânico , Propriedades de Superfície
6.
J Biomed Mater Res B Appl Biomater ; 96(2): 199-206, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21210498

RESUMO

Extracellular matrix (ECM) materials are currently utilized for soft tissue repair applications such as vascular grafts, tendon reconstruction, and hernia repair. These materials are derived from tissues such as human dermis and porcine small intestine submucosa, which must be rendered acellular to prevent disease transmission and decrease the risk of an immune response. The ideal decellularization technique removes cells and cellular remnants, but leaves the original collagen architecture intact. The tissue utilized in this study was the central tendon of the porcine diaphragm, which had not been previously investigated for soft tissue repair. Several treatments were investigated during this study including peracetic acid, TritonX-100, sodium dodecyl sulfate, and tri(n-butyl) phosphate (TnBP). Of the decellularization treatments investigated, only 1% TnBP was effective in removing cell nuclei while leaving the structure and composition of the tissue intact. Overall, the resulting acellular tissue scaffold retained the ECM composition, strength, resistance to enzymatic degradation, and biocompatibility of the original tissue, making 1% TnBP an acceptable decellularization treatment for porcine diaphragm tendon.


Assuntos
Regeneração Tecidual Guiada/métodos , Organofosfatos/farmacologia , Tendões/efeitos dos fármacos , Alicerces Teciduais , Animais , Métodos , Sus scrofa
7.
J Biomed Mater Res B Appl Biomater ; 96(2): 351-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21210516

RESUMO

Two novel, bionanocomposite scaffolds were evaluated in a rodent model over the course of three months to determine whether these scaffolds possessed adequate biocompatibility characteristics to warrant further evaluation as possible tissue reconstruction scaffolds. These bionanocomposite scaffolds were comprised of amine-functionalized gold nanoparticles (AuNP) or silicon carbide nanowires (SiCNW) crosslinked to an acellular porcine diaphragm tendon. It was hypothesized that the addition of nanomaterials to the porcine tendon would also improve its biocompatibility by imparting a nanostructured surface. As early as seven days after implantation, both types of bionanocomposite scaffolds displayed evidence of granulation tissue and the beginning of scaffold remodeling with new collagen deposited by the host, and by ninety-seven days the bionanocomposite scaffolds were completely remodeled with no evidence of any adverse host tissue reaction or scar tissue formation. The AuNP bionanocomposite scaffolds exhibited accelerated scaffold remodeling compared to the SiCNW scaffolds.


Assuntos
Materiais Biocompatíveis/uso terapêutico , Implantes Experimentais , Nanopartículas Metálicas/uso terapêutico , Nanocompostos/química , Nanofios/uso terapêutico , Tendões/transplante , Alicerces Teciduais/química , Aminas , Animais , Materiais Biocompatíveis/química , Compostos Inorgânicos de Carbono , Ouro , Teste de Materiais , Nanopartículas Metálicas/química , Nanocompostos/uso terapêutico , Nanofios/química , Compostos de Silício , Suínos , Engenharia Tecidual/métodos
8.
Endoscopy ; 41(12): 1062-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19967621

RESUMO

BACKGROUND AND STUDY AIMS: Incisional abdominal wall hernias currently require repair with open or laparoscopic surgery, which is associated with wound complications and recurrent hernia formation. Natural orifice transluminal endoscopic surgery (NOTES) techniques may have the potential to decrease the morbidity associated with hernia repair. The aim of this study was to repair a chronic ventral hernia with a biologic mesh placed transgastrically in a porcine model. MATERIALS AND METHODS: Six pigs underwent creation of an incisional abdominal wall hernia. At least 4 weeks later, transgastric repair was done using an underlay biologic mesh with at least 5 cm of overlap from the hernia fascial edge. The mesh was secured with transfascial sutures and the stomach was closed with a sutured gastropexy. Pigs were evaluated 2 weeks later by laparoscopy. Pigs were sacrificed and necropsy wa s performed 4 weeks after the repair. RESULTS: Six pigs underwent hernia repair lasting a mean (+/- SD) of 204 +/- 123 minutes, with one perioperative death. At 2 weeks after hernia repair, laparoscopy showed significant adhesions in all pigs; one pig had extensive mesh infection and was sacrificed. Necropsy on one pig at 2 weeks and four pigs at 4 weeks showed complete coverage of the hernia defect in all pigs. All pigs had mesh abscesses or a positive mesh culture. CONCLUSION: Transgastric repair of a chronic ventral hernia is technically feasible. Difficulties with mesh delivery and infection need to be overcome before this approach can be used in humans.


Assuntos
Endoscopia/métodos , Hérnia Abdominal/cirurgia , Telas Cirúrgicas , Animais , Feminino , Técnicas de Sutura , Suínos
9.
Hernia ; 13(6): 597-603, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19590817

RESUMO

PURPOSE: To evaluate the effectiveness of the retrorectus mesh repair for midline ventral hernias. METHODS: A retrospective review of all consecutive patients having a retrorectus mesh repair by a single surgeon in a standardized fashion from 1991 to 2005. All procedures used polyester (Mersilene) mesh with at least 5-cm overlap beyond the repair in all directions. RESULTS: Ninety patients were identified, 56% of which were female. Major postoperative complications occurred in 23 (26%) patients, including nine (10%) patients requiring reoperative treatment due to skin flap necrosis, wound infection, hematoma, or fascial dehiscence. Partial mesh excision was required in four patients. The hernia recurrence rate was 7% at a mean of 53 months. CONCLUSION: The retrorectus repair with polyester mesh is an effective and durable repair for midline ventral hernias. The disadvantage of this repair is the large number of wound complications.


Assuntos
Hérnia Ventral/cirurgia , Telas Cirúrgicas , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Adulto , Idoso , Feminino , Hematoma/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Necrose/etiologia , Poliésteres , Recidiva , Estudos Retrospectivos , Pele/patologia , Procedimentos Cirúrgicos Operatórios/métodos , Deiscência da Ferida Operatória/etiologia , Infecção da Ferida Cirúrgica/etiologia
10.
Endoscopy ; 40(7): 589-94, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18609453

RESUMO

BACKGROUND AND STUDY AIMS: Safe, reliable, and efficient endoscopic closure of a colotomy is paramount for endoscopic full thickness excision of the colon. Two newly developed devices, the Tissue Apposition System (TAS) and the InScope Multi-Clip Applier (IMCA), may help to achieve this. The aim of this study was to determine the feasibility of using each device to close colotomies after full thickness wall excisions. MATERIAL AND METHODS: 12 pigs were used in the study. After laparoscopic full thickness excision of the colonic wall, the defect was closed using either the TAS or the IMCA. Closure was performed under laparoscopic vision. Success of colotomy closure, time taken for colotomy closure, postoperative infections, and complication rates were recorded. RESULTS: Complete closure was achieved in 6/6 pigs in the TAS group. In 5/6 pigs in the IMCA group closure was successful; in one pig laparoscopic assistance was used. Median closure time (range) was significantly lower in the TAS group at 48 minutes (15 - 51) vs. 76 minutes (43 - 145) in the IMCA group. There were no postoperative infections or complications. CONCLUSIONS: Endoscopic closure after full thickness colonic wall excision is feasible with both the TAS and the IMCA. Closure times are significantly shorter and handling is easier with the TAS. Combined use of both systems might be beneficial.


Assuntos
Colo/cirurgia , Colonoscopia , Instrumentos Cirúrgicos , Animais , Estudos de Viabilidade , Laparoscopia , Suínos
11.
Surg Innov ; 14(3): 168-76, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17928615

RESUMO

Although polypropylene has been used as a hernia repair material for nearly 50 years, very little science has been applied to studying the body's effect on this material. It is possible that oxidation of mesh occurs as a result of the chemical structure of polypropylene and the physiological conditions to which it is subjected; this leads to embrittlement of the material, impaired abdominal movement, and chronic pain. It is also possible that lightweight polypropylene meshes undergo less oxidation due to a reduced inflammatory reaction. The objective of this study was to characterize explanted hernia meshes using techniques such as scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and compliance testing to determine whether the mesh density of polypropylene affects the oxidative degradation of the material. The hypothesis was that heavyweight polypropylene would incite a more intense inflammatory response than lightweight polypropylene and thus undergo greater oxidative degradation. Overall, the results support this theory.


Assuntos
Hérnia Abdominal/cirurgia , Próteses e Implantes , Varredura Diferencial de Calorimetria , Feminino , Humanos , Pessoa de Meia-Idade , Polipropilenos , Recidiva , Termogravimetria , Tomografia Computadorizada por Raios X
12.
J Biomed Mater Res B Appl Biomater ; 83(1): 44-9, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17285608

RESUMO

Hernia repair with prosthetic mesh significantly decreases the rate of recurrence compared with traditional, primary suture repair by reducing the tension on the edges of the wound. However, there are several complications associated with the use of mesh that may be due to the chronic inflammatory reaction to the mesh or a loss of compliance after degradation of the material. Mesh contraction and migration can also occur, sometimes resulting in a recurrent hernia. Based on the chemical structure of the polypropylene mesh material and the physiological conditions to which it is subjected, it is possible that oxidation is responsible for these changes in material properties. Oxidation would result in surface cracking, decreased melting temperature, loss of mass, and reduced compliance of the material. The objective of this study was to identify physiochemical changes in the surface and bulk properties of explanted polypropylene hernia meshes compared to pristine polypropylene mesh materials. Several characterization techniques were utilized, including scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and compliance testing. Overall, the results supported our hypothesis that oxidation is involved with the degradation of polypropylene hernia mesh materials.


Assuntos
Materiais Biocompatíveis , Polipropilenos , Próteses e Implantes , Telas Cirúrgicas , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Hérnia Abdominal/cirurgia , Humanos , Teste de Materiais , Oxirredução , Polipropilenos/química , Polipropilenos/metabolismo , Desenho de Prótese , Estresse Mecânico , Propriedades de Superfície
13.
Hernia ; 11(3): 279-85, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17279319

RESUMO

Chronic infection of a prosthetic mesh implant is a severe complication of ventral hernia repair, and mesh explantation is usually required in these cases. Biologic mesh implants have a possible role in ventral hernia repair in this setting. Here we present a case of chronic mesh infection following ventral hernia repair and the use of a biologic mesh to repair the existing defect following explantation of the infected mesh. Analysis of the explant material demonstrated possible oxidative degradation of the original polypropylene. A review of the literature follows.


Assuntos
Materiais Biocompatíveis , Colágeno , Hérnia Ventral/cirurgia , Politetrafluoretileno/efeitos adversos , Implantação de Prótese/instrumentação , Infecções Relacionadas à Prótese/cirurgia , Telas Cirúrgicas/efeitos adversos , Seguimentos , Hérnia Ventral/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Implantação de Prótese/efeitos adversos , Infecções Relacionadas à Prótese/diagnóstico por imagem , Infecções Relacionadas à Prótese/etiologia , Reoperação , Telas Cirúrgicas/microbiologia , Tomografia Computadorizada por Raios X , Cicatrização
14.
Surg Endosc ; 20(9): 1482-7, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16865628

RESUMO

BACKGROUND: Carbon dioxide (CO2) pneumoperitoneum has been shown to attenuate the inflammatory response after laparoscopy. This study tested the hypothesis that abdominal insufflation with CO2 improves survival in an animal model of sepsis and investigated the associated mechanism. METHODS: The effect of CO2, helium, and air pneumoperitoneum on mortality was studied by inducing sepsis in 143 rats via intravenous injection of lipopolysaccharide (LPS). To test the protective effect of CO2 in the setting of a laparotomy, an additional 65 animals were subjected to CO2 pneumoperitoneum, helium pneumoperitoneum, or the control condition after laparotomy and intraperitoneal LPS injection. The mechanism of CO2 protection was investigated in another 84 animals. Statistical significance was determined via Kaplan-Meier analysis for survival and analysis of variance (ANOVA) for serum cytokines. RESULTS: Among rats with LPS-induced sepsis, CO2 pneumoperitoneum increased survival to 78%, as compared with using helium pneumoperitoneum (52%; p < 0.05), air pneumoperitoneum (55%; p = 0.09), anesthesia control (50%; p < 0.05), and LPS-only control (42%; p < 0.01). Carbon dioxide insufflation also significantly increased survival over the control condition (85% vs 25%; p < 0.05) among laparotomized septic animals, whereas helium insufflation did not (65% survival). Carbon dioxide insufflation increased plasma interleukin-10 (IL-10) levels by 35% compared with helium pneumoperitoneum (p < 0.05), and by 34% compared with anesthesia control (p < 0.05) 90 min after LPS stimulation. Carbon dioxide pneumoperitoneum resulted in a threefold reduction in tumor necrosis factor-alpha (TNF-alpha) compared with helium pneumoperitoneum (p < 0.05), and a sixfold reduction with anesthesia control (p < 0.001). CONCLUSION: Abdominal insufflation with CO2, but not helium or air, significantly reduces mortality among animals with LPS-induced sepsis. Furthermore, CO2 pneumoperitoneum rescues animals from abdominal sepsis after a laparotomy. Because IL-10 is known to downregulate TNF-alpha, the increase in IL-10 and the decrease in TNF-alpha found among the CO2-insufflated animals in our study provide evidence for a mechanism whereby CO2 pneumoperitoneum reduces mortality via IL-10-mediated downregulation of TNF-alpha.


Assuntos
Dióxido de Carbono , Pneumoperitônio Artificial , Sepse/mortalidade , Abdome/microbiologia , Animais , Regulação para Baixo , Interleucina-10/metabolismo , Laparotomia/efeitos adversos , Lipopolissacarídeos , Masculino , Ratos , Ratos Sprague-Dawley , Terapia de Salvação , Sepse/induzido quimicamente , Sepse/etiologia , Análise de Sobrevida , Fator de Necrose Tumoral alfa/antagonistas & inibidores
15.
Surg Endosc ; 19(8): 1035-44, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16235129

RESUMO

BACKGROUND: Carbon dioxide (CO(2)) pneumoperitoneum alters the inflammatory response in animal models of sepsis. The spleen is a key organ in inflammation and its removal was predicted to modify this effect. METHODS: The acute phase inflammatory response to lipopolysaccharide (LPS) challenge in male rats was examined for the effects of splenectomy (spx) and the technique of removal (open or laparpscopic). A series of experiments compared LPS-only controls with LPS injection 2 or 9 days following open spx, lap CO2 spx, open sham, or lap CO2 sham. The method of splenectomy was studied by randomization to control, open spx, lap CO2 spx, lap helium (He) spx, or lap air spx with LPS challenge on postoperative day 2. Serum levels of tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (INF-gamma) and, interleutin (IL) 10 were collected at multiple time points, assayed by commercial enzyme-linked immunosorbent assay, analyzed by analysis of variance. RESULTS: Levels of TNF-alpha at 1.5 were significantly lower following open sham than following lap sham (p < 0.05). Splenectomy drastically reduced INF-gamma and TNF-alpha levels compared to controls (p < 0.05) on postoperative day 2. No method of spx preserved TNF-alpha or INF-gamma responses. Recovery of TNF-alpha response on day 9 was delayed in the spx groups. CONCLUSIONS: Splenectomy dramatically reduces TNF-alpha and INF-gamma responses to LPS challenge, although by different mechanisms. Pneumoperitoneum-mediated modulation of the septic inflammatory response is partially dependent on the spleen.


Assuntos
Reação de Fase Aguda/etiologia , Laparoscopia , Baço/imunologia , Esplenectomia/efeitos adversos , Esplenectomia/métodos , Reação de Fase Aguda/sangue , Animais , Dióxido de Carbono , Interferon gama/sangue , Interleucina-10/sangue , Lipopolissacarídeos/administração & dosagem , Masculino , Pneumoperitônio Artificial , Ratos , Ratos Sprague-Dawley , Sepse/sangue , Sepse/etiologia , Sepse/imunologia , Fator de Necrose Tumoral alfa/análise
16.
J Dairy Sci ; 88(4): 1364-9, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15778304

RESUMO

Sixteen crossbred (British x Continental; average un-shrunk body weight = 507.9 kg; SD = 45.6 kg) beef heifers fed a steam-flaked corn-based finishing diet with melengestrol acetate (0.4 mg/heifer daily) included to suppress estrus were used in a completely random design to evaluate the efficacy of buccal administration of 0, 10, 100, or 1000 mg of 25-hydroxyvitamin D3, (25-OH D3). Serum Ca, P, Mg, 25-OH D3, 1,25-dihydroxyvitamin D [1,25-(OH)2 D3], albumin, and protein were measured 24 h before dosing (-24 h), at dosing (0 h), and 6 and 24 h after dosing, after which the cattle were slaughtered at a commercial facility. Samples of kidneys, liver, longissimus lumborum, and triceps brachii were collected and evaluated for concentrations of 1,25-(OH)2 D3. With -24 and 0 h as baseline covariates, a significant time x treatment interaction was observed for serum 25-OH D3 and Ca concentrations, but not for serum 1,25-(OH)2 D3. Supplemental 25-OH D3 doses of 100 and 1000 mg significantly increased serum 25-OH D3 at 24 h after dosing, 1,25-(OH)2 D3 at 6 and 24 h after dosing, and serum Ca at 24 h after dosing. Similarly, buccal dosing of 1000 mg of supplemental 25-OH D3 significantly increased (approximately 2- to 3-fold) concentrations of 1,25-(OH)2 D3 in the kidney, liver, and longissimus lumborum relative to the other 3 treatments but not in triceps brachii. Serum albumin, protein, P, and Mg were not affected by treatment. Based on these results, buccal administration of 100 and 1000 mg 25-OH D3 increased vitamin D3 metabolites in serum and tissues, and it should be an effective method of delivering the vitamin.


Assuntos
Bovinos/metabolismo , Vitamina D/análogos & derivados , Vitamina D/administração & dosagem , Vitamina D/metabolismo , Administração Bucal , Ração Animal , Animais , Bovinos/sangue , Colecalciferol/administração & dosagem , Colecalciferol/metabolismo , Colecalciferol/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Rim/metabolismo , Fígado/metabolismo , Carne/normas , Músculo Esquelético/metabolismo , Distribuição Aleatória , Vitamina D/sangue , Vitamina D/farmacocinética
17.
Surg Endosc ; 19(4): 477-83, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15696360

RESUMO

BACKGROUND: The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) Learning Center is a group of educational "classrooms" designed to tutor meeting attendees on specific technology-intensive content areas. The objectives of the Robotics Station were to familiarize participants with basic laparoscopic skills as implemented with surgical robotic assistance and to help them explore the benefits and drawbacks of using robotics in their institutions. METHODS: Sixty-six volunteer surgeon attendees of the 2003 SAGES meeting representing a diverse group of backgrounds and possessing varying levels of surgical experience were directed through a series of drills on two different surgical robots. Each participant was directed through a series of three drills that practiced surgically relevant skills. Participants were given feedback on their performance. They then completed a 12-question computer-based questionnaire that surveyed their personal demographic backgrounds, their impressions of robotic surgery, and their opinions regarding the learning center's utility in educating them about new technology. RESULTS: Sixty-eight percent of participants had never used a surgical robot, and 89% had never used a robot clinically. Eighty-eight percent of respondents found one or both robots easier to use than they had expected, and 91% found that one or both robots made simple surgical tasks easier compared to standard laparoscopy. Sixty-four percent of participants stated that they were more likely to pursue purchase of a robotic system for use in their practice as a result of their exposure to robotics in the Learning Center. After completing the Robotics Station, 80% of surgeons believed that current surgical robots are of clinical benefit. However, 71% of participants stated that surgical robotic systems priced above $500,000 would not be financially viable in their practices. CONCLUSION: The structured learning environment used in the SAGES Learning Center fostered among participants a positive attitude toward surgical robotics. The format of their exposure to this technology at the Robotics Station also enabled participants to gauge the potential financial value of surgical robots in clinical practice. The SAGES Learning Center Robotics Station succeeded in exposing surgeons to surgical robotics in a way that helped them assess the value of this technology for their individual practices and institutions.


Assuntos
Educação Médica Continuada , Endoscopia Gastrointestinal/métodos , Endoscopia/educação , Cirurgia Geral/educação , Robótica , Adulto , Atitude do Pessoal de Saúde , Currículo , Endoscopia Gastrointestinal/economia , Endoscopia Gastrointestinal/psicologia , Humanos , Internato e Residência , Laparoscopia/economia , Laparoscopia/métodos , Procedimentos Cirúrgicos Minimamente Invasivos , Prática Profissional/estatística & dados numéricos , Robótica/instrumentação , Robótica/métodos , Sociedades Médicas , Inquéritos e Questionários
18.
Surg Endosc ; 18(11): 1640-4, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15580445

RESUMO

BACKGROUND: We examined the effects of an identical period of pneumoperitoneum applied at three different time points after lipopolysaccharide (LPS) challenge. Two different insufflation gases were also compared. METHODS: Male rats (n = 70) were injected intravenously with 1 mg/kg of LPS (time 0). The time relationship between a 1.5-h period of insufflation and initial LPS stimulation was the experimental variable. All rats were killed 6 h after injection. CO2 and helium insufflation were investigated. Ten control rats received LPS only. Serum interleukin-6 (IL-6) levels were determined by enzyme-linked immunosorbent assay (ELISA). Hepatic expression of alpha2-macroglobulin, beta-fibrinogen, and metallothionein were measured by Northern blot analysis. Statistical analysis was performed using one-way analysis of variance (ANOVA). RESULTS: Expression of alpha2-macroglobulin mRNA was lower in CO2 groups compared to the control group (p < 0.05 at time 120 and 270). beta-Fibrinogen message was diminished in CO2 0 and 120 groups compared to control. Serum levels of IL-6 and expression of metallothionein mRNA did not show significant differences between groups. CONCLUSIONS: These findings suggest that CO2 pneumoperitoneum downregulates the inflammatory response to LPS challenge. Start time of CO2 insufflation does not appear to alter hepatic expression of acute phase genes. The mechanism of alpha2-macroglobulin downregulation does not appear to be due to IL-6.


Assuntos
Dióxido de Carbono/farmacologia , Fibrinogênio/biossíntese , Hélio/farmacologia , Pneumoperitônio Artificial/métodos , alfa-Macroglobulinas/biossíntese , Animais , Fibrinogênio/análise , Fibrinogênio/genética , Inflamação/sangue , Lipopolissacarídeos/farmacologia , Masculino , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , alfa-Macroglobulinas/análise , alfa-Macroglobulinas/genética
19.
J Gen Virol ; 78 ( Pt 6): 1389-98, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9191935

RESUMO

Degenerate and specific PCR assays were developed for bovine leukaemia virus (BLV) and/or primate T cell leukaemia/lymphoma viruses (PTLV). The degenerate assays detected all major variants of the BLV/PTLV genus at a sensitivity of 10-100 copies of input DNA; the specific systems detected 1-10 copies of input target. Sensitivity was 100% in specific DNA-PCR assays done on peripheral blood from seropositive BLV-infected cattle and HTLV-I- or HTLV-II-infected humans, and 62% in RNA/DNA-PCR assays on sera from BLV seropositive cattle. The pol fragments from 21 different BLV strains, isolated from cattle in North and Central America, were cloned and sequenced, and compared to other published BLV and PTLV pol sequences. BLV and PTLV sequences differed by 42%. Sequence divergence was up to 6% among the BLV strains, and up to 36% among the PTLV strains (with PTLV-I and PTLV-II differing among themselves by 15% and 8%, respectively). Some cows were infected with several BLV strains. Among retroviruses, BLV and PTLV sequences formed a distinct clade. The data support the interpretation that BLV and PTLV evolved from a common ancestor many millennia ago, and some considerable time before the PTLV-I and PTLV-II strains diverged from each other. The dissemination of the BLV strains studied probably resulted from the export of European cattle throughout the world over the last 500 years. The relatively similar mutation rates of BLV and PTLV, after their various points of divergence, suggest that there could be a much wider genetic range of BLV than has currently been defined.


Assuntos
Vírus da Leucemia Bovina/isolamento & purificação , Reação em Cadeia da Polimerase , Primatas/virologia , Retroviridae/isolamento & purificação , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , Linhagem Celular , Humanos , Vírus da Leucemia Bovina/classificação , Vírus da Leucemia Bovina/genética , Dados de Sequência Molecular , Filogenia , Retroviridae/classificação , Retroviridae/genética
20.
Psychiatr Serv ; 47(8): 837-41, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8837155

RESUMO

OBJECTIVE: States finance some community-based mental health services through purchase-of-service contracts. The study examined ways in which six states monitor these contracts. METHODS: Data were gathered during site visits to Massachusetts, Michigan, New York, Oregon, Tennessee, and Texas, where more than 100 state policy makers, providers, consumers, and advocates were interviewed about mental health purchase-of-service contracting. Relevant documents about contracting practices for mental health services in each state were also examined. RESULTS: Findings suggest that states monitor their mental health contracts in two ways. First, long-term contracts are monitored using traditional methods, focusing on the structure and process of delivering services. Newer contracts for specific services are more likely to be monitored using performance measures currently being developed. States have had difficulty creating and implementing performance-based contracting for publicly funded mental health services. CONCLUSIONS: It is likely that contracting will continue to be the method states use for future policy initiatives. It may be more appropriate for policy makers to set their sights on developing a simplified set of outcome measures that will give them some information about provider performance, even if the information is imperfect.


Assuntos
Serviços Comunitários de Saúde Mental/normas , Serviços Contratados/normas , Avaliação de Resultados em Cuidados de Saúde , Administração em Saúde Pública , Análise Custo-Benefício , Política de Saúde/economia , Pesquisa sobre Serviços de Saúde , Humanos , Programas de Assistência Gerenciada/economia , Estados Unidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...