RESUMO
The tolerance of fish to fasting offers a model to study the regulatory mechanisms and changes produced when feeding is restored. Gilthead sea bream juveniles were exposed to a 21-days fasting period followed by 2 h to 7-days refeeding. Fasting provoked a decrease in body weight, somatic indexes, and muscle gene expression of members of the Gh/Igf system, signaling molecules (akt, tor and downstream effectors), proliferation marker pcna, myogenic regulatory factors, myostatin, and proteolytic molecules such as cathepsins or calpains, while most ubiquitin-proteasome system members increased or remained stable. In bone, downregulated expression of Gh/Igf members and osteogenic factors was observed, whereas expression of the osteoclastic marker ctsk was increased. Refeeding recovered the expression of Gh/Igf system, myogenic and osteogenic factors in a sequence similar to that of development. Akt and Tor phosphorylation raised at 2 and 5 h post-refeeding, much faster than its gene expression increased, which occurred at day 7. The expression in bone and muscle of the inhibitor myostatin (mstn2) showed an inverse profile suggesting an inter-organ coordination that needs to be further explored in fish. Overall, this study provides new information on the molecules involved in the musculoskeletal system remodeling during the early stages of refeeding in fish.
Assuntos
Remodelação Óssea , Comportamento Alimentar , Proteínas de Peixes/metabolismo , Músculos/citologia , Fatores de Regulação Miogênica/metabolismo , Dourada/metabolismo , Animais , Jejum , Proteínas de Peixes/genética , Desenvolvimento Muscular , Músculos/metabolismo , Fatores de Regulação Miogênica/genética , Proteólise , Dourada/genética , Dourada/crescimento & desenvolvimento , Ubiquitina/metabolismoRESUMO
Food handlers are important sources of contamination in the agricultural environment. This study was conducted (i) to evaluate the activity of antimicrobial soaps against Escherichia coli and Enterococcus faecalis using a hand washing model with soiled hands and (ii) to determine the survival and persistence of these bacteria in rinsates. Sterilized agricultural soil from tomato and pepper farms was inoculated with E. coli or E. faecalis at 103 or 106 CFU/g. Decontaminated hands were placed in contact with contaminated soil for 2 min and were then washed with soaps with or without antimicrobial compounds (citric extracts, chloroxylenol, triclosan, or chlorhexidine gluconate). As the control, hands were washed with sterile distilled water. The levels of bacteria remaining on the hands and recovered from the rinsates were determined using a membrane filtration method and selective media. Antimicrobial soaps removed levels of E. coli similar to those removed by distilled water and nonantimicrobial soap on hands contaminated with E. coli at 103 CFU/g. However, when hands were contaminated with E. coli at 106 CFU/g, more E. coli was removed with the chlorhexidine gluconate soap. When hands were contaminated with E. faecalis at 103 CFU/g, bacteria were removed more effectively with soaps containing chloroxylenol or chlorhexidine gluconate. When hands were contaminated with E. faecalis at 106 CFU/g, all of the antimicrobial soaps were more effective for removing the bacteria than were distilled water and nonantimicrobial soap. E. coli grew in all of the hand washing rinsates except that containing triclosan, whereas E. faecalis from the 106 CFU/g treatments grew in rinsates containing chlorhexidine gluconate and in the distilled water rinsates. Washing with antimicrobial soap was more effective for reducing bacteria on soiled hands than was washing with water or nonantimicrobial soap. However, persistence or growth of bacteria in these rinsates poses health risks.
Assuntos
Anti-Infecciosos/farmacologia , Enterococcus faecalis/isolamento & purificação , Escherichia coli/isolamento & purificação , Desinfecção das Mãos/métodos , Bactérias , Contagem de Colônia Microbiana , Mãos , Humanos , SabõesRESUMO
BACKGROUND: Coordinated, multi-component school-based interventions can improve health behaviors in children, as well as parents, and impact the weight status of students. By leveraging a unique collaboration between Texas AgriLife Extension (a federal, state and county funded educational outreach organization) and the University of Texas School of Public Health, the Texas Grow! Eat! Go! Study (TGEG) modeled the effectiveness of utilizing existing programs and volunteer infrastructure to disseminate an enhanced Coordinated School Health program. The five-year TGEG study was developed to assess the independent and combined impact of gardening, nutrition and physical activity intervention(s) on the prevalence of healthy eating, physical activity and weight status among low-income elementary students. The purpose of this paper is to report on study design, baseline characteristics, intervention approaches, data collection and baseline data. METHODS: The study design for the TGEG study consisted of a factorial group randomized controlled trial (RCT) in which 28 schools were randomly assigned to one of 4 treatment groups: (1) Coordinated Approach to Child Health (CATCH) only (Comparison), (2) CATCH plus school garden intervention [Learn, Grow, Eat & Go! (LGEG)], (3) CATCH plus physical activity intervention [Walk Across Texas (WAT)], and (4) CATCH plus LGEG plus WAT (Combined). The outcome variables include student's weight status, vegetable and sugar sweetened beverage consumption, physical activity, and sedentary behavior. Parents were assessed for home environmental variables including availability of certain foods, social support of student health behaviors, parent engagement and behavior modeling. RESULTS: Descriptive data are presented for students (n = 1369) and parents (n = 1206) at baseline. The sample consisted primarily of Hispanic and African American (53 % and 18 %, respectively) and low-income (i.e., 78 % eligible for Free and Reduced Price School Meals program and 43 % food insecure) students. On average, students did not meet national guidelines for vegetable consumption or physical activity. At baseline, no statistical differences for demographic or key outcome variables among the 4 treatment groups were observed. CONCLUSIONS: The TGEG study targets a population of students and parents at high risk of obesity and related chronic conditions, utilizing a novel and collaborative approach to program formulation and delivery, and a rigorous, randomized study design.
Assuntos
Jardinagem/métodos , Promoção da Saúde/métodos , Pobreza/psicologia , Serviços de Saúde Escolar , Estudantes/psicologia , Peso Corporal , Criança , Análise por Conglomerados , Etnicidade , Exercício Físico/psicologia , Feminino , Jardins , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Instituições Acadêmicas , Texas , VerdurasRESUMO
The antimicrobial and antioxidant activities of some cultivars of the nopal cactus have not been determined. In this study, 8 cultivars of nopal cacti from Mexico were assayed for phenolic content, antioxidant activities, and antimicrobial activities against Campylobacter Jejuni, Vibrio cholera, and Clostridium Perfringens. Plant material was washed, dried, and macerated in methanol. Minimum bactericidal concentrations (MBCs) were determined using the broth microdilution method. Antioxidant activities were quantitatively determined using spectrophotometric methods. The MCBs of the nopal cacti ranged from 1.1 to 12.5 mg/mL for c. jejuni, 4.4 to 30 mg/mL for V. cholera, and 0.8 to 16 mg/mL for C. perfringens in the cultivars Cardon Blanco, Real de Catorce, and Jalpa, respectively. High quantities of total phenols and total flavonoids were found in the Jalpa cacti (3.80 mg of gallic acid equivalent GAE/g dry weight [DW] and 36.64 mg of quercetin equivalents [QE]/g DW, respectively). 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities (RSA) were correlated to bioactive compound contents. The Villanueva cacti had the highest %RSA at 42.31%, and the lowest activity was recorded in Copena V1 at 19.98%. In conclusion, we found that some of the 8 cactus pear cultivars studied may be used for their antioxidant compounds or antimicrobials to control or prevent the contamination of foods.
Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Flavonoides/farmacologia , Opuntia/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Antibacterianos/análise , Antioxidantes/análise , Compostos de Bifenilo/análise , Compostos de Bifenilo/metabolismo , Compostos de Bifenilo/farmacologia , Flavonoides/análise , Ácido Gálico/análise , Ácido Gálico/farmacologia , México , Opuntia/classificação , Oxirredução , Fenóis/análise , Picratos/metabolismo , Extratos Vegetais/química , Caules de Planta/química , Quercetina/análise , Quercetina/farmacologia , Especificidade da EspécieRESUMO
AIMS: The antimicrobial activity of Acacia farnesiana against Vibrio cholerae has been demonstrated; however, no information regarding its active compound or its mechanism of action has been documented. METHODS AND RESULTS: The active compound was isolated from A. farnesiana by bioassay-guided fractionation and identified as methyl gallate by nuclear magnetic resonance (NMR) techniques ((1) H NMR and (13) C NMR). The minimum bactericidal concentration (MBC) of methyl gallate and its effect on membrane integrity, cytoplasmic pH, membrane potential, ATP synthesis and gene expression of cholera toxin (ctx) from V. cholerae were determined. The MBC of methyl gallate ranged from 30 ± 1 to 50 ± 1 µg ml(-1) . Methyl gallate affected cell membrane integrity, causing a decrease in cytoplasmic pH (pHin , from 7·3 to <3·0), and membrane hyperpolarization, and ATP was no longer produced by the treated cells. However, methyl gallate did not affect ctx gene expression. CONCLUSIONS: Methyl gallate is a major antimicrobial compound from A. farnesiana that disturbs the membrane activity of V. cholerae. SIGNIFICANCE AND IMPACT OF THE STUDY: The effects of methyl gallate validate several traditional antimicrobial uses of A. farnesiana, and it is an attractive alternative to control V. cholerae.
RESUMO
Este trabalho objetivou avaliar características fisiológicas, morfológicas e a produção de inflorescências em cultura de Calendula officinalis em função do fornecimento de cama-de-frango de corte semidecomposta. O experimento conduzido em Latossolo Vermelho distroférrico contou com quatro tratamentos, a testemunha, cama incorporada, cama em cobertura e cama em cobertura (50 por cento) mais incorporada (50 por cento) na dose 20 t ha-1. Empregou-se o delineamento experimental de blocos casualizados em parcelas subdivididas, com seis repetições. Os valores de matéria fresca e seca dos capítulos florais decresceram com o tempo de cultivo. As formas de fornecimento da cama-de-frango não interferiram na síntese de clorofila (44,812 µg cm-2), no metabolismo fotossintético (20,938 µmol m-2 s-1) e na transpiração das plantas (6,750 Mmol m-2 s-1), com valores mais elevados aos 112 dias após o transplantio. A maior produção total de capítulos foi observada sob cultivo com cama-de-frango 50 por cento incorporada e 50 por cento em cobertura (1361,16 kg ha-1) e a menor no tratamento testemunha (939,28 kg ha-1).
This study aimed to evaluate physiological and morphological characteristics of inflorescences in culture of Calendula officinalis according to the supply of semi-decomposed poultry manure. The experiment was conducted in dystrophic Red Latosol and included four treatments: control, incorporate litter, cover litter and cover (50 percent) incorporated (50 percent) litter at the level 20 t ha-1. The randomized split-plot block design was adopted, with six replicates. The values of fresh and dry matter of capitula decreased with the cultivation time. The forms of chicken manure supply did not interfere with chlorophyll synthesis (44.812 µg cm²) and photosynthetic metabolism (20.938 µmol m-2 s-1) and plant transpiration (6.750 Mmol m-2 s-1), with the highest values at 112 days after transplanting. At 126 days after transplanting, the highest production of capitula (16.0 capitula plant -1) was verified for the treatment cover (50 percent) incorporated (50 percent) litter, with the highest diameter (46 to 50mm) incorporated. The highest total production of capitula was observed for cultivation with 50 percent incorporated and 50 percent cover poultry manure (1362.16 kg ha-1) and the lowest production was noted for the control treatment (939.28 ha-1).
Assuntos
Esterco/análise , Calendula/crescimento & desenvolvimento , Fertilizantes , Flores/crescimento & desenvolvimento , Substratos para Tratamento Biológico/análise , Brasil , Plantas Medicinais/crescimento & desenvolvimentoRESUMO
AIM: The mechanisms of adaptation of Clostridium perfringens to high temperatures are not well understood. In this work, the involvement of extracellular compounds in protection to heat was determined. METHODS AND RESULTS: Cells were grown in fluid thioglycollate medium or chicken broth. When mid-log phase was reached, they were heat-shocked at 50 degrees C for 30 min. Then cultures were centrifuged and supernatants were transferred to nonshocked cells. Heat tolerance of these cells was performed at 55 degrees C. Viable cells were determined. In some cases, supernatants were heated at 65 degrees C or 100 degrees C or treated with trypsin. Supernatants were fractionated and PAGE was made of fractions showing heat-protective activity. When C. perfringens was exposed to a heat shock at 50 degrees C, extracellular factors were found in the culture supernatant that provided protection to cells not exposed to a heat shock. The extracellular factors were sensitive to heat and trypsin treatment suggesting a protein component. SDS-PAGE analysis of supernatant fractions from heat-treated cells revealed two induced proteins (56 and 125 kDa) that could be involved in heat tolerance. CONCLUSION: In this work, the presence and thermoprotective activity of extracellular factors produced by C. perfringens under a heat shock was demonstrated. SIGNIFICANCE AND IMPACT OF THE STUDY: The detection of thermoprotective extracellular factors of C. perfringens will aid in our understanding of the physiology of survival of C. perfringens in foods.
Assuntos
Adaptação Fisiológica , Proteínas de Bactérias/biossíntese , Clostridium perfringens/fisiologia , Temperatura Alta , Proteínas de Bactérias/química , Eletroforese em Gel de Poliacrilamida , Viabilidade Microbiana , Peso MolecularRESUMO
BACKGROUND: This study evaluates whether surgical strategies such as the portosystemic shunt and ischemic preconditioning can protect against hepatic and pulmonary injury associated with liver transplantation. METHODS: The effect of the portosystemic shunt, ischemic preconditioning, and both surgical procedures together were evaluated in rat liver transplantation. Alanine aminotransferase, hyaluronic acid levels in plasma, adenosine triphosphate and nucleotide levels in liver and edema, malondialdehyde levels, and myeloperoxidase activity were measured 24 hr posttransplantation. Plasmatic tumor necrosis factor (TNF) levels were measured as a possible proinflammatory factor responsible for hepatic and pulmonary damage associated with liver transplantation. RESULTS: Hepatocyte and cell endothelial damage were observed in liver grafts subjected to 8 hr of cold ischemia. This was associated with increased plasma TNF levels and lung inflammatory response. Portosystemic shunt application in the recipient protected endothelial cells but did not confer an effective protection from hepatocyte damage or reduce the increased plasma TNF levels and lung damage after liver transplantation. However, preconditioning of the donor liver conferred protection against both the endothelial cell and hepatocyte damage observed after liver transplantation. Preconditioning also attenuated the increased plasma TNF release and pulmonary damage. The combination of both surgical strategies resulted in levels of liver injury, TNF, and lung damage similar to those seen after liver transplantation. CONCLUSIONS: These findings indicate that ischemic preconditioning could be a preferred treatment to reduce hepatic and pulmonary damage associated with liver transplantation. However, this strategy may not be effective in several clinical situations requiring a portosystemic shunt.
Assuntos
Precondicionamento Isquêmico , Hepatopatias/prevenção & controle , Transplante de Fígado , Pneumopatias/prevenção & controle , Derivação Portossistêmica Cirúrgica , Animais , Temperatura Baixa , Metabolismo Energético , Hepatócitos/metabolismo , Hepatócitos/patologia , Hepatopatias/patologia , Hepatopatias/cirurgia , Pneumopatias/patologia , Masculino , Complicações Pós-Operatórias/patologia , Complicações Pós-Operatórias/prevenção & controle , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Eighty-eight samples of ground meat were randomly collected from retail stores in the metropolitan area of Monterrey, Mexico, and were analyzed for microbial contamination. Methods were those recommended by the Mexican regulation and/or the U.S. Food and Drug Administration. Over 75% of the samples contained > 10(5) total mesophilic microorganisms per g, and over 40% had >10(6) total coliforms per g. Fecal coliforms were present in most samples. Staphylococcus aureus was detected in 2.3% of the samples, Salmonella spp. in 11.4%, Listeria spp. in 62%, and L. monocytogenes in 16%. Escherichia coli was detected in 76% of samples, but none was serotype O157:H7. Shigella spp. was not found in any sample. Fusarium spp. and Mucor spp. were detected in 3.4% of the samples, and low levels of yeast in 93%. The microbiological quality of the ground meat analyzed was unsatisfactory, and the product could be an important cause of food poisoning.
Assuntos
Contaminação de Alimentos/análise , Microbiologia de Alimentos , Produtos da Carne/microbiologia , Animais , Bovinos , Contagem de Colônia Microbiana , Enterobacteriaceae/isolamento & purificação , Escherichia coli/isolamento & purificação , Listeria/isolamento & purificação , México , Salmonella/isolamento & purificaçãoRESUMO
In the present study, 304 samples of herbs and spices (garlic powder, cumin seeds, black pepper, oregano, and bay leaves) widely used in Mexico were analyzed for the presence of Bacillus cereus, Salmonella Typhi, Shigella dysenteriae, Escherichia coli, total and fecal coliforms, total mesophilic aerobic organisms, and fungi. Samples were nonpackaged or packaged in polyethylene bags or glass containers. High levels (10(5) to 10(7) CFU/g) of mesophilic aerobic microorganisms were found in most of the samples of garlic powder, cumin seed, and black pepper. Lower levels (<102 CFU/g) were found in oregano and bay leaves. Total and fecal coliforms counts were dependent on the type of packaging. More than 70% of the polyethylene-packaged samples had less than 10(3) CFU/g of microorganisms. Glass and nonpackaged spices showed lower levels of these microorganisms. B. cereus was present in 32 samples of which most were polyethylene packaged. The other pathogenic bacteria were not detected. Aspergillus niger was detected in 29% of the samples, Rhizopus sp. in 19%, and Penicillum sp. and Cunninghamella in 8%.
Assuntos
Bactérias/crescimento & desenvolvimento , Microbiologia de Alimentos , Fungos/crescimento & desenvolvimento , Magnoliopsida/microbiologia , Especiarias/microbiologia , Bactérias/isolamento & purificação , Contagem de Colônia Microbiana , Enterobacteriaceae/crescimento & desenvolvimento , Enterobacteriaceae/isolamento & purificação , Manipulação de Alimentos , Fungos/isolamento & purificação , MéxicoRESUMO
The induction of acid-shock proteins and the degree of acid resistance conferred on Clostridium perfringens by acid shock, and the kinetics of this resistance were determined. A sublethal acid shock at pH 4.5 for 20 min increased the acid tolerance of cells at least fifteenfold. The acquired tolerance was maintained for 3 h after acid treatment. The response of the microorganism to acid shock was also examined by analysis of pulse-labeled proteins. Five acid-shock proteins (molecular weights 120, 84, 58, 45 and 17 kDa) were identified by polyacrylamide gel electrophoresis.
Assuntos
Clostridium perfringens/metabolismo , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Clostridium perfringens/classificação , Clostridium perfringens/efeitos dos fármacos , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de HidrogênioRESUMO
Clostridium perfringens has been implicated as a causative agent of foodborne poisoning, infectious diarrhea (not associated with foods), gas gangrene, and several veterinary diseases. Fecal carriage of enterotoxigenic strains of this bacterium appears to be important in the development of infectious diarrhea and as a source of C. perfringens contamination of foods. In this work, carriage of this bacterium in feces of a Mexican population was analyzed. C. perfringens was found in 126 of the 200 fecal samples obtained from healthy individuals from northern Mexico. The samples had an average of 7.4 x 10(3) spores per gram, with the elderly population showing the highest levels. Dot blot analyses using a dig-labeled probe specific for the enterotoxin gene showed that 7% of the samples had isolates with toxigenic potential.
Assuntos
Portador Sadio/diagnóstico , Clostridium perfringens/isolamento & purificação , Sondas de DNA , Enterotoxinas/genética , Fezes/microbiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-IdadeRESUMO
Application of a heat shock (43 to 50 degrees C) applied early during the sporulation process of Clostridium perfringens delayed spore and enterotoxin production. Final levels of heat-resistant spores were similar to the control, but enterotoxin levels were reduced when the heat shock was applied at the third hour of incubation. The response of the microorganism to the heat shock was also examined by analysis of pulse-labeled proteins. Seven heat shock proteins (HSPs) associated with vegetative cells were identified by polyacrylamide gel electrophoresis. Most were localized mainly in the membrane, although one small protein was mostly present in the cytoplasm. Fewer HSPs were detected during sporulation. Two HSPs were immunologically related to the GroEL and DnaK HSPs from Lactobacillus lactis and Escherichia coli, respectively.
Assuntos
Clostridium perfringens/crescimento & desenvolvimento , Clostridium perfringens/metabolismo , Enterotoxinas/biossíntese , Proteínas de Choque Térmico/biossíntese , Temperatura Alta , Western Blotting , Clostridium perfringens/química , Eletroforese em Gel de Poliacrilamida , Proteínas de Choque Térmico/análise , EsporosRESUMO
Several reports on the microbiology of spices and herbs indicate the presence of Clostridium perfringens, a spore-forming foodborne pathogen responsible for gastrointestinal disease. In the present study, a total of 380 samples of spices and herbs (cumin seed, black pepper, oregano, garlic powder, and bay leaves) widely used in Mexico were analyzed for the presence of C. perfringens, and the enterotoxigenicity of the isolates was determined by a dot-blot technique using an enterotoxin degoxigenin-labeled DNA probe. C. perfringens counts varied from <100 to 433 CFU/g in garlic powder, from <100 to 200 CFU/g in black pepper, from <100 to 433 CFU/g in cumin seed, from <100 to 340 CFU/g in oregano, and from < 100 to 450 CFU/g in bay leaves. The dot-blot technique detected the enterotoxin gene in 8 (4.25%) of 188 confirmed isolates of C. perfringens. dot-blot.
Assuntos
Clostridium perfringens/isolamento & purificação , Especiarias/microbiologia , Clostridium perfringens/genética , Contagem de Colônia Microbiana , DNA Bacteriano/análise , Enterotoxinas/genética , México , Técnicas de Sonda Molecular , Vigilância de Produtos ComercializadosRESUMO
An in vitro study of laser tissue welding mediated with a dye-enhanced protein patch was conducted. Fresh sections of porcine aorta were used for the experiments. Arteriotomies were treated using an indocyanine green dye-enhanced collagen patch activated by an 805-nm continuous-wave fiber-delivered diode laser. Temperature histories of the surface of the weld site were obtained using a hollow glass optical fiber-based two-color infrared thermometer. The experimental effort was complemented by simulations with the LATIS (LAser-TISsue) computer code, which uses coupled Monte Carlo, thermal transport, and mass transport models. Comparison of simulated and experimental thermal data indicated that evaporative cooling clamped the surface temperature of the weld site below 100 °C. For fluences of approximately 200 J/cm2, peak surface temperatures averaged 74°C and acute burst strengths consistently exceeded 0.14×106 dyn/cm (hoop tension). The combination of experimental and simulation results showed that the inclusion of water transport and evaporative losses in the computer code has a significant impact on the thermal distributions and hydration levels throughout the tissue volume. The solid-matrix protein patch provided a means of controllable energy delivery and yielded consistently strong welds. © 1998 Society of Photo-Optical Instrumentation Engineers.
RESUMO
An in vitro study of laser tissue welding mediated with a dye-enhanced protein solder was performed. Freshly harvested sections of porcine aorta were used for the experiments. Arteriotomies approximately 4 mm in length were treated using an 805 nm continuous-wave diode laser coupled to a 1-mm diameter fiber. Temperature histories of the surface of the weld site were obtained using a fiberoptic-based infrared thermometer. The experimental effort was complemented by the LATIS (LAser-TISsue) computer code, which numerically simulates the exposure of tissue to near-infrared radiation using coupled Monte Carlo, thermal transport, and mass transport models. Comparison of the experimental and simulated thermal results shows that the inclusion of water transport and evaporative losses in the model is necessary to determine the thermal distributions and hydration state in the tissue. The hydration state of the weld site was correlated with the acute weld strength.
Assuntos
Fotocoagulação a Laser/métodos , Animais , Aorta/fisiologia , Aorta/cirurgia , Simulação por Computador , Dessecação , Suínos , Temperatura , ÁguaRESUMO
OBJECTIVE: This study examines the use of dye-enhanced protein bonding agents in 805 nm diode laser-assisted tissue welding. A comparison of an albumin liquid solder and collagen solid-matrix patches used to repair arteriotomies in an in vitro porcine model is presented. SUMMARY BACKGROUND DATA: Extrinsic bonding media in the form of solders and patches have been used to enhance the practice of laser tissue welding. Preferential absorption of the laser wavelength has been achieved by the incorporation of chromophores. METHODS: Both the solder and the patch included indocyanine green dye (ICG) to absorb the 805 nm continuous-wave diode laser light used to perform the welds. Solder-mediated welds were divided into two groups (high power/short exposure and low power/long exposure), and the patches were divided into three thickness groups ranging from 0.1 to 1.3 mm. The power used to activate the patches was constant, but the exposure time was increased with patch thickness. RESULTS: Burst pressure results indicated that solder-mediated and patched welds yielded similar average burst strengths in most cases, but the patches provided a higher success rate (i.e., more often exceeded 150 mmHg) and were more consistent (i.e., smaller standard deviation) than the solder. The strongest welds were obtained using 1.0-1.3 mm thick patches, while the high power/short exposure solder group was the weakest. CONCLUSIONS: Though the solder and patches yielded similar acute weld strengths, the solid-matrix patches facilitated the welding process and provided consistently strong welds. The material properties of the extrinsic agents influenced their performance.
Assuntos
Albuminas/química , Colágeno/química , Corantes/química , Verde de Indocianina/química , Fotocoagulação a Laser/instrumentação , Análise de Variância , Anastomose Cirúrgica/métodos , Animais , Aorta/cirurgia , Fenômenos Biomecânicos , Estudos de Avaliação como Assunto , Gelatina/química , Semicondutores , SuínosRESUMO
Dilution methods were employed to determine the effect of ethanolic extracts of Agave lecheguilla Torr. (Agavaceae), Baccharis glutinosa Pers. (Compositae) and Larrea tridentata (DC.) Cov. (Zygophyllaceae) on growth of yeasts, molds and bacteria. The three extracts analyzed showed good antimicrobial activity against more than one organism. The minimal inhibitory concentration of the extracts was also determined.
Assuntos
Anti-Infecciosos/farmacologia , Extratos Vegetais/farmacologia , Antibacterianos , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , México , Testes de Sensibilidade Microbiana , Plantas MedicinaisRESUMO
La mayoría de los modelos experimentales en cirugía laparoscópica se practican en animales porcino y caninos; algunos inconvenientes que presentan estas especies son alto costo y que requieren de personal especializado para su manejo. La rata, animal ampliamente utilizado en microcirugía (investigación y docencia), es una especie que puede ser empleada en la laparoscopia para adiestramiento especialmente del cirujano pediatra y en la investigación. En el presente trabajo se comparan los resultados obtenidos con la operación de Nissen abierta y con técnica laparoscópica. Se emplearon 24 ratas cepa Wistar de 250 a 300 g de peso anestesiadas con pentotal, las cuales fueron divididas en tres grupos. En el grupo 1 (n =.8) se midió la presión intragástrica necesaria para producir reflujo esofágico (11 mmHg en promedio); en el grupo 2 (n = 8) se efectuó la funduplicatura con técnica abierta y medición de presiones intragástricas hasta obtener reflujo. Al grupo 3 (n = 8) se le determinaron los mismos parámetros después de practicada la funduplicatura por vía laparoscópica. La presión necesaria para producir reflujo fue similar en los grupos 2 y 3 (60 a 80 mmHg). el modelo esperimental diseñado es económico, de fácil montaje si se cuenta con experiencia en las técnicas laparoscópicas donde se emplean dos manos y se ralizan suturas
Assuntos
Animais , Laparoscopia , Laparoscopia/estatística & dados numéricos , Ratos Wistar , Procedimentos Cirúrgicos Operatórios , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricosRESUMO
The effect of human bile juice and bile salts (sodium cholate, sodium taurocholate, sodium glycochenodeoxycholate and sodium chenodeoxycholate) on growth, sporulation and enterotoxin production by enterotoxin-positive and enterotoxin-negative strains of Clostridium perfringens was determined. Each bile salt inhibited growth to a different degree. A mixture of bile salts completely inhibited the growth of enterotoxin-positive strains of this organism. Human bile juice completely inhibited the growth of all the strains at a dilution of 1:320. A distinct stimulatory effect of the bile salts on sporulation was observed in the case of C. perfringens strains NCTC 8239 and NCTC 8679. The salts also increased enterotoxin concentrations in the cell extracts of the enterotoxin-positive strains tested. No effect on enterotoxin production was detected when an enterotoxin-negative strain was examined.