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1.
J Appl Microbiol ; 119(6): 1613-23, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26274630

RESUMO

AIM: To investigate the effect of corn starch (CS) edible films with spice oils on the stability of raw beef during refrigerated storage. METHODS AND RESULTS: The antimicrobial properties of corn starch films containing 0-4·0% (w/v) ratios of clove (CL) and cinnamon (CI) essential oils (EOs) were tested against seven meat spoilage organisms by zone inhibition test. Effects of CS films containing 3% CL or CI or a mixture of CL + CI were also tested in raw beef stored at 4°C. Meat samples were analysed for pH, microbial counts, colour values and Thiobarbituric acid reactive substances (TBARS) values for a period of 15 days. CS films with CL + CI resulted in a significant reduction in microbial populations in the meat samples and also improved meat colour stability at the end of storage period. CONCLUSIONS: The incorporation of spice EOs in CS films may provide antimicrobial and antioxidant activities that could improve the stability of raw meat. SIGNIFICANCE AND IMPACT OF THE STUDY: Results from this study may be applied in meat industries as an additional barrier to control microbial spoilage as well as lipid oxidation in meat products.


Assuntos
Antibacterianos , Conservação de Alimentos/métodos , Óleos Voláteis , Carne Vermelha/microbiologia , Amido , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Bovinos , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Especiarias , Amido/química , Amido/farmacologia , Zea mays
2.
Curr Microbiol ; 70(6): 898-906, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25842173

RESUMO

A high-throughput method is described, consisting of a colourimetric microtitration for screening phenol-degrading microorganisms, using a mixture of 4-aminoantipyrine and potassium ferricyanide as the colour indicator. This contemporary study summarizes a new method to determine phenol-degrading bacteria isolated from different areas. The method was used for testing a total of 72 bacteria collected from the natural environment and five known strains obtained from diagnostic and research laboratories employing 200 mg/L phenol (the linear range saturation concentration). Depending on the change in colour indicator, the degradation profiles of 11 strains of bacteria are shown, of which seven strains were able to degrade more than 80 % of phenol within 6-8 h, while the other four strains took 12-24 h. Two of the environmentally isolated strains showed high efficiency of phenol degradation and were confirmed by the high-performance liquid chromatography analysis. These strains were identified by 16S rRNA sequencing as unique (Escherichia coli moh1 and Bacillus cereus moh2) and were deposited in the GenBank of NCBI. Two pathogenic strains (Uropathogenic E. coli and Salmonella sp.) were found to be the fast degraders of phenol, which is of medical concern, as phenol is generally used as a disinfectant in hospitals. This method can be used for the estimation and screening of phenol degraders in a single step, for its application in bioremediation as well as in hospitals for screening the phenol resistance of pathogens.


Assuntos
Bacillus cereus/metabolismo , Técnicas Bacteriológicas/métodos , Colorimetria/métodos , Enterobacteriaceae/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Fenol/metabolismo , Bacillus cereus/classificação , Bacillus cereus/genética , Bacillus cereus/isolamento & purificação , Biotransformação , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Enterobacteriaceae/classificação , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Fatores de Tempo
3.
Ecotoxicol Environ Saf ; 121: 180-5, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25866205

RESUMO

Wastewater treatment plant incorporates physical, chemical and biological processes to treat and remove the contaminants. The main drawback of conventional activated sludge process is the huge production of excess sludge, which is an unavoidable byproduct. The treatment and disposal of excess sludge costs about 60% of the total operating cost. The ideal way to reduce excess sludge production during wastewater treatment is by preventing biomass formation within the aerobic treatment train rather than post treatment of the generated sludge. In the present investigation two different mechanical devices namely, Ultrasonic and Shear Gap homogenizers have been employed to disintegrate the aerobic biomass. This study is intended to restrict the multiplication of microbial biomass and at the same time degrade the organics present in wastewater by increasing the oxidative capacity of microorganisms. The disintegrability on biomass was determined by biochemical methods. Degree of inactivation provides the information on inability of microorganisms to consume oxygen upon disruption. The soluble COD quantifies the extent of release of intra cellular compounds. The participation of disintegrated microorganism in wastewater treatment process was carried out in two identical respirometeric reactors. The results show that Ultrasonic homogenizer is very effective in the disruption of microorganisms leading to a maximum microbial growth reduction of 27%. On the other hand, Shear gap homogenizer does not favor the sludge growth reduction rather it facilitates the growth. This study also shows that for better microbial growth reduction, floc size reduction alone is not sufficient but also microbial disruption is essential.


Assuntos
Oxigênio/análise , Esgotos/microbiologia , Sonicação/métodos , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Aerobiose , Biomassa , Fenômenos Biomecânicos , Desenho de Equipamento , Consórcios Microbianos , Esgotos/química , Sonicação/instrumentação , Eliminação de Resíduos Líquidos/instrumentação
4.
Environ Technol ; 35(17-20): 2194-203, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25145172

RESUMO

Microbial desalination cell (MDC) is a bioelectrochemical system developed recently from microbial fuel cells (MFCs), for producing green energy from organic wastes along with desalination of saltwater. MDC is proved to be a better performer than MFC in terms of power output and chemical oxygen demand removal, with desalination as an additional feature. This study investigates the application potential of MDC for integrated biodegradation of waste engine oil. This study showed, for the first time, that waste engine oil could be used as an organic substrate in MDC, achieving biodegradation of engine oil along with considerable desalination and power production. Utilization of these wastes in MDC can protect the environment from waste engine oil contamination. Indigenous oil-degrading bacteria were isolated and identified from engine oil contaminated sludge. Degradation of waste engine oil by these novel isolates was studied in batch cultures and optimized the growth conditions. The same cultures when used in MDC, gave enhanced biodegradation (70.1 +/- 0.5%) along with desalination (68.3 +/- 0.6%) and power production (3.1 +/- 0.3 mW/m2). Fourier transform-infrared spectroscopy and gas chromatography-mass spectrometry analyses were performed to characterize the degradation metabolites in the anolyte of MDC which clearly indicated the biodegradation of long chain, branched and cyclic hydrocarbons present in waste engine oil.


Assuntos
Bacillus subtilis/metabolismo , Biodegradação Ambiental , Fontes de Energia Bioelétrica , Reatores Biológicos/microbiologia , Petróleo/metabolismo , Cloreto de Sódio/isolamento & purificação , Bacillus subtilis/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Concentração de Íons de Hidrogênio , Petróleo/análise , Cloreto de Sódio/química , Temperatura
5.
J Clin Invest ; 74(1): 161-4, 1984 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6736247

RESUMO

Marrow radioiron uptake and marrow blood flow were measured in order to evaluate iron supply for erythropoiesis. Normal, phenylhydrazine-treated and bled animals were studied. The plasma iron turnover of seven normal rabbits was 1.49 +/- 0.22 mg/dl whole blood per d, of 11 rabbits treated 4 d before with phenylhydrazine was 5.16 +/- 1.81, and of four bled animals the plasma iron turnover was 3.75 +/- 1.61. The cardiac output and the percentage of blood flow to the marrow was increased in phenylhydrazine-treated and bled animals. Marrow iron flow in phenylhydrazine-treated animals was 38.3 +/- 32.6 micrograms/min per kg as compared with control values of 7.0 +/- 1.3 (P less than 0.01). This was due to an increase in marrow flow, an increase in plasma iron, and an increase in plasmatocrit. In bled animals, in spite of an increased marrow blood flow, marrow iron flow of 7.3 +/- 2.2 was similar to that of control animals due to a lower plasma iron concentration. The calculated marrow iron extraction of 3.7 +/- 2.4% in phenylhydrazine-treated animals was not different from that of control animals of 4.3 +/- 1.1, whereas extraction was increased in bled animals to 7.9 +/- 1.3 (P less than 0.01). In additional studies of transfused animals, acutely induced anemia was associated with an increased cardiac output, but also with a relative decrease in marrow flow, which left marrow iron supply unaffected. It would appear from these studies that an important mechanism for meeting the increased iron requirement of the hyperplastic erythroid marrow is an increase in marrow blood flow.


Assuntos
Eritropoese , Ferro/metabolismo , Animais , Medula Óssea/irrigação sanguínea , Medula Óssea/fisiologia , Débito Cardíaco , Hematócrito , Ferro/sangue , Masculino , Fenil-Hidrazinas/toxicidade , Coelhos , Fluxo Sanguíneo Regional
6.
J Clin Invest ; 92(6): 2761-7, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8254030

RESUMO

We have pursued our findings of glutathione reductase (GSSG-R) deficiency and disturbed glutathione in cancer patients treated with 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU), by investigating how thiol metabolism, cell proliferation, and the nitrosourea interact in human K562 leukemia. Fasting cells arrested in G greatly increased their reduced glutathione (GSH) in response to growth factors. The rise in thiol began after several hours, peaked before DNA synthesis, and resulted from increased production. BCNU inactivated GSSG-R rapidly, and later retarded, doubled, and greatly prolonged GSH formation before stopping DNA synthesis. Pretreatment unlike post treatment with buthionine-S-R-sulfoximine (BSO) diminished BCNU's ability to block GSSG-R. Enzyme inhibition decreased with falling cellular GSH. In the leukemia system as in vivo, sequential BCNU-induced thiol alterations heralded delayed antiproliferative effects. Drug timing markedly affected both thiol and DNA syntheses. By destroying GSSG-R and delaying the upregulation of thiol synthesis while escalating GSH utilization and requirements, the nitrosourea created a striking and previously unrecognized window of vulnerability for GSH-dependent processes. During this period, altered GSH metabolism could contribute indirectly to BCNU's pleiotropic effects by interfering with DNA alkylation repair, glucose decarboxylation, deoxyribose formation, and possibly by influencing other aspects of proliferation. Acquired GSSG-R deficiency was also an early and sensitive marker for prodrug breakdown and activation.


Assuntos
Carmustina/farmacologia , Divisão Celular/efeitos dos fármacos , Glutationa Redutase/antagonistas & inibidores , Glutationa/metabolismo , Butionina Sulfoximina , Ciclo Celular , Linhagem Celular , Reparo do DNA , DNA de Neoplasias/biossíntese , DNA de Neoplasias/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Cinética , Leucemia Mielogênica Crônica BCR-ABL Positiva , Metionina Sulfoximina/análogos & derivados , Metionina Sulfoximina/farmacologia , Células Tumorais Cultivadas
7.
Poult Sci ; 96(8): 2839-2844, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28520947

RESUMO

This study investigates the integrated approach of spice extracts and modified atmospheric packaging (MAP) chicken meat preservation. Specifically, extracts from clove (CL), cinnamon (CI) individually and in combination (3% w/w) along with MAP (30% CO2/70% N2 and 10% O2/30% CO2/60% N2) were used to increase the shelf life of fresh chicken meat stored at 4°C. The parameters evaluated as shelf life indications are microbiological (total viable count, Pseudomonas spp., lactic acid bacteria (LAB), and Enterobacteriaceae), physicochemical (pH, Lipid oxidation, color changes) and Sensory attributes. Microbial population were reduced by 2.5 to 5 log cfu/g, with the greater impact being accomplished by the blend of clove and cinnamon extract with 30% CO2/70% N2 MAP. Thiobarbituric values for all treated and MAP packed samples remained lower than 1 mg malondialdehyde (MDA)/kg all through the 24 day storage period. pH values varied from 5.5 for fresh sample on day 0 to 7.11 (day 25) on combined extract treated and MAP packaged samples. The estimations of the color parameters L*, a*, and b* were well maintained in oxygen deficient MAP. Finally, sensory investigation demonstrated that combined clove and cinnamon extract of 3% conferred acceptable sensory attributes to the samples on day 24 of storage. These results indicate the extended shelf life of chicken meat from 4 days to 24 days for samples when coated with 3% of combined clove and cinnamon extract and packaged under MAP without oxygen. These pooled extracts along with MAP displayed expanded the usability and the organoleptic qualities of chicken meat.


Assuntos
Microbiologia de Alimentos , Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Carne/análise , Especiarias/análise , Animais , Galinhas , Cinnamomum zeylanicum/química , Syzygium/química
8.
Int J Biol Macromol ; 83: 385-95, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26592701

RESUMO

Starch from Tamarind seed is considered to be a nonedible and inexpensive component, with many industrial applications. Extraction and characterization of tamarind seed starch was carried out for the synthesis of biopolymer. Tamarind seeds were collected, cleaned and further roasted, decorticated, and pulverized to get starch powder. Total starch content present in each tamarind seed is estimated to be around 65-70%. About 84.68% purified starch can be recovered from the tamarind seed. Defatted Tamarind seed starch has an amylose content of 27.55 wt.% and 72.45 wt.% of amylopectin. Morphological (SEM) and X-ray diffraction were used to evaluate crystallinity. Likewise, TGA and DSC of starch have also been analyzed. Thermal properties of starch obtained from tamarind seeds showed good thermal stability when compared to other starch sources such as Mesquite seed and Mango kernel. This study proved that the tamarind seed starch can be used as a potential biopolymer material. Thermo-stable biofilms were produced through initial optimization studies. Predictive response surface quadratic models were constructed for prediction and optimization of biofilm mechanical properties. Correlation coefficient values were calculated to me more than 0.90 for mechanical responses which implies the fitness of constructed model with experimental data.


Assuntos
Celulose/química , Amido/química , Fenômenos Mecânicos , Tamanho da Partícula , Sementes/química , Tamarindus/química , Temperatura
9.
Biochim Biophys Acta ; 795(2): 271-6, 1984 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-6433983

RESUMO

The uptake of arachidonate and stearate from serum-free media by endothelial cells was investigated over a 48 h period. Arachidonate was rapidly incorporated into both the phospholipids and triacylglycerols. Triacylglycerol incorporation reached a maximum at 2 h and then rapidly declined with a concomitant increase in phospholipid incorporation. High initial arachidonate incorporation into phosphatidylcholine was followed by a partial transfer of that arachidonate to phosphatidylethanolamine. In contrast, stearate was slowly incorporated into all of the phospholipids and was not incorporated into the triacylglycerols. Cells stimulated with A23187 for 24 h cleaved stearate from all the phospholipids equally, whereas more arachidonate was cleaved from phosphatidylethanolamine than from the other phospholipids. Released arachidonate was both metabolized and reacylated into the triacylglycerols. Our results suggest that triacylglycerols serve as a modulator of intracellular arachidonate concentrations in endothelial cells.


Assuntos
Aorta/metabolismo , Ácidos Araquidônicos/metabolismo , Fosfolipídeos/biossíntese , Triglicerídeos/biossíntese , 6-Cetoprostaglandina F1 alfa/biossíntese , Animais , Ácido Araquidônico , Calcimicina/farmacologia , Bovinos , Células Cultivadas , Endotélio/efeitos dos fármacos , Endotélio/metabolismo , Cinética , Fosfolipídeos/isolamento & purificação , Radioimunoensaio/métodos , Ácidos Esteáricos/metabolismo
10.
Health Care Financ Rev ; 19(1): 161-200, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-10179997

RESUMO

The national health expenditures (NHE) series presented in this report for 1960-96 provides a view of the economic history of health care in the United States through spending for health care services and the sources financing that care. In 1996 NHE topped $1 trillion. At the same time, spending grew at the slowest rate, 4.4 percent, ever recorded in the current series. For the first time, this article presents estimates of Medicare managed care payments by type of service, as well as nursing home and home health spending in hospital-based facilities.


Assuntos
Gastos em Saúde/estatística & dados numéricos , Prescrições de Medicamentos/economia , Economia , Gastos em Saúde/tendências , Serviços de Assistência Domiciliar/economia , Humanos , Seguro Saúde/economia , Programas de Assistência Gerenciada/economia , Medicare/estatística & dados numéricos , Casas de Saúde/economia , Estados Unidos
11.
Lipids ; 21(1): 21-5, 1986 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3083172

RESUMO

The applicability of a stable isotope method to monitor the mixing of dietary arachidonic acid with endogenous arachidonic acid in tissue lipids was evaluated. Rats were fed octadeuterated arachidonic acid during a 20-day period, and the entry of the dietary acid into lipid esters of various tissues was examined by gas chromatography-mass spectrometric (GC-MS) analysis of their fatty acids. The rats were maintained on a fat-free diet from weaning until 63 days old to enhance the ratio of the dietary acid to endogenous arachidonate. Three separate forms of eicosatetraenoic acid in the tissue lipids could be distinguished by GC-MS: octadeuterated arachidonic acid (recent dietary origin), unlabeled arachidonic acid (maternal origin) and unlabeled 4,7,10,13-eicosatetraenoic acid (originating from palmitoleic acid). The total eicosatetraenoic acid in the tissue lipids contained about 90% arachidonate from recent dietary origin in lung, kidney, heart and fat, 70% in muscle and liver and 27% in brain. The n-7 isomer of eicosatetraenoic acid was estimated to make up 6% or less of the total eicosatetraenoic acid in lung, kidney, brain, muscle and heart tissue lipids, but it comprised around 15% of the total eicosatetraenoic acid in liver. The unlabeled arachidonic acid of maternal origin thus comprised only about 10% of the eicosatetraenoic acid in all tissues examined except muscle and brain, where it was 24% and 70% of the eicosatetraenoic acid, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Ácidos Araquidônicos/metabolismo , Gorduras na Dieta/metabolismo , Administração Oral , Animais , Ácido Araquidônico , Ácidos Araquidônicos/administração & dosagem , Deutério , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Ratos , Ratos Endogâmicos , Distribuição Tecidual
12.
Int J Food Microbiol ; 171: 32-40, 2014 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-24308943

RESUMO

The antimicrobial and antioxidant effects of different spice extracts in raw chicken meat during storage for 15 days at 4 °C were studied. Raw chicken meat was treated with BHT (positive control), Syzygium aromaticum (SA), Cinnmomum cassia (CC), Origanum vulgare (OV), and Brassica nigra (BN) extracts and the different combinations as well as the results were compared to raw chicken meat without any additive (negative control). The antioxidant and antimicrobial activities of spice extracts were determined. Total phenolic contents and flavonoid contents were ranged from 14.09 ± 0.78 to 24.65 ± 0.83 mg of GAE/g and 7.07 ± 0.15 to 12.13 ± 0.24 mg of quercetin/g, respectively. The pH, instrumental color (CIE L*, a*, b*), total viable counts (TVC), Lactic Acid Bacteria (LAB) counts, Enterobacteriaceae counts, Pseudomonas spp. counts and 2-thiobarbituric acid reactive substances (TBARS) were determined at a gap of 3 days interval for a period of 15 days. The bacterial counts of T-W-SA+T-W-CC+T-W-OV samples were lower than control samples during storage. T-W-SA+T-W-CC+T-W-OV samples maintained significantly (P<0.05) higher L*, a* and b* values while storing. The TBARS values of T-W-SA+T-W-CC+T-W-OV samples were lowest among the samples. These results show that spice extracts are very effective against microbial growth, lipid oxidation and has potential as a natural antioxidant in raw chicken meats.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Microbiologia de Alimentos , Conservação de Alimentos/normas , Carne/microbiologia , Extratos Vegetais/farmacologia , Especiarias , Animais , Bactérias/efeitos dos fármacos , Galinhas , Flavonoides/análise , Testes de Sensibilidade Microbiana , Origanum/química , Fenóis/análise , Substâncias Reativas com Ácido Tiobarbitúrico
13.
Carbohydr Polym ; 98(1): 89-94, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23987320

RESUMO

In the present investigation, the polysaccharide/mucilage from waste of Abelmoscus esculentus by modification in hot extraction using two different solvents (Acetone, Methanol) were extracted, characterized and further compared with seaweed polysaccharide for their potential applications. The percentage yield, emulsifying capacity and swelling index of this mucilage were determined. The macro algae and okra waste, gave high % yield (22.2% and 8.6% respectively) and good emulsifying capacity (EC%=52.38% and 54.76% respectively) with acetone, compared to methanol (11.3% and 0.28%; EC%=50%) (PH=7) while swelling index was greater with methanol than acetone extracts respectively. The infrared (I.R.) spectrum of the samples was recorded to investigate the chemical structure of mucilage. Thermal analysis of the mucilage was done with TGA (Thermal Gravimetric Analyzer) and DSC (Differential Scanning Calorimeter) which showed both okra and algal polysaccharide were thermostable hydrogels.


Assuntos
Mucilagem Vegetal/isolamento & purificação , Engenharia Tecidual , Abelmoschus/química , Acetona/química , Fracionamento Químico , Metanol/química , Mucilagem Vegetal/química , Solventes/química , Temperatura
14.
J Hazard Mater ; 179(1-3): 318-22, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20359816

RESUMO

A laboratory study was undertaken to examine the temporal changes in physico-chemical properties during vermicomposting of sago industry waste. The sago industry waste was blended with cow dung, poultry manure at various proportions, kept for pre-treatment for 21 days and subsequently vermicomposted for a period of 45 days under shade. Earthworm species (Eisenia foetida) was introduced at the rate of 50 g/kg of waste. The substrate moisture content and temperature were monitored regularly. The vermicomposts were sampled at 0, 15, 30 and 45 days for the assessment of temporal changes in physico-chemical properties. The data revealed vermicomposting of sago wastes, cow dung and poultry manure mixed at equal proportion (1:1:1) produced a superior quality manure with desirable C:N ratio and higher nutritional status than composting. E. foetida is an earthworm suitable for composting organic wastes such as poultry manure with extreme pH and high temperature and sago waste with high organic carbon in a shorter period of time. This study suggests that the sago industry solid waste could be effectively converted into highly valuable manure that can be exploited to promote crop production.


Assuntos
Resíduos Industriais/análise , Manihot/química , Solo/análise , Animais , Carbono/análise , Bovinos , Umidade , Concentração de Íons de Hidrogênio , Índia , Esterco/análise , Nitrogênio/análise , Estado Nutricional , Oligoquetos , Aves Domésticas , Temperatura
16.
Anesthesiology ; 62(5): 588-96, 1985 May.
Artigo em Inglês | MEDLINE | ID: mdl-3994024

RESUMO

The authors studied the effect of halothane in a canine model of coronary collateral circulation secondary to chronic occlusion of a coronary artery. Two sets of experiments were performed. In the first experiments, Ameroid constrictors were placed around the left anterior descending coronary artery to produce complete occlusion in three weeks. An inflatable occluder was placed around the circumflex coronary artery in order to apply a mild stenosis to the artery supplying the collateral vessels to produce vasodilation distal to the stenosis. Regional myocardial blood flows were measured using radioactive microspheres. Blood flows to normal and collateralized myocardium were decreased significantly during halothane anesthesia, but perfusion of the subendocardium in both regions was maintained even in the presence of mild stenosis of the circumflex coronary artery supplying the collateral vessels, as indicated by unchanged endocardial/epicardial blood flow ratios. In the second experiments, chronic occlusions of both circumflex and right coronary arteries were produced using Ameroid constrictors. In these animals, sedated using xylazine, pacing-induced tachycardia produced a marked but reversible decrease in blood flow to the collateralized subendocardium. During halothane anesthesia at normal heart rate, blood flow to the collateralized subendocardium was well maintained, but tachycardia produced marked decrease in blood flow to the collateralized subendocardium, leading to the demise of four of seven dogs. The authors conclude that in this chronic canine model, in which control measurements were made during sedation using xylazine, coronary collateral blood flow is well maintained during halothane anesthesia at normal heart rate, but tachycardia during halothane anesthesia severely limits blood flow to the collateralized subendocardium.


Assuntos
Circulação Colateral/efeitos dos fármacos , Circulação Coronária/efeitos dos fármacos , Doença das Coronárias/fisiopatologia , Halotano/farmacologia , Hidrogéis , Animais , Materiais Biocompatíveis , Estimulação Cardíaca Artificial , Caseínas , Constrição Patológica , Doença das Coronárias/etiologia , Modelos Animais de Doenças , Cães , Feminino , Frequência Cardíaca , Masculino , Microesferas
17.
Anesth Analg ; 63(5): 503-10, 1984 May.
Artigo em Inglês | MEDLINE | ID: mdl-6424509

RESUMO

We used the radioactive microsphere method to measure and compare the effects of sodium nitroprusside (SNP) and nitroglycerin (NTG) on organ blood flow during hypotension induced by each drug. The study was done in 10 dogs anesthetized using 0.7% end-tidal halothane. Each animal received both SNP and NTG to decrease the mean arterial blood pressure (MABP) to 45 mm Hg, but the sequence in which the drugs were administered was alternated. Five of the dogs received SNP first and five received NTG first. Organ blood flow was measured after a stable period of hypotension that was brief by necessity in order to avoid cyanide toxicity due to increasing dose requirements for SNP. Measurements were made before and during hypotension induced with each drug. The mean duration of stable hypotension was shorter (P less than 0.05) with NTG (5 +/- 1 min) (mean +/- SEM) than with SNP (7 +/- 1 min). During NTG-induced hypotension, blood flows to the brain, kidneys, liver, gastrointestinal tract, pancreas, and skeletal muscle were maintained at control levels. During SNP-induced hypotension, blood flows to the myocardium, liver, gastrointestinal tract, pancreas, and skeletal muscle were maintained at control levels. NTG increased myocardial blood flow (P less than 0.05), while SNP decreased blood flow to brain (P less than 0.05) and kidneys (P less than 0.01). Both drugs decreased blood flow to the spleen (P less than 0.001). Our results indicate that during the first few minutes of NTG-induced hypotension, blood flows to all organs except the spleen are well-maintained, while the first few minutes of SNP-induced hypotension are associated with decreases in blood flow to brain and kidneys as well as to the spleen.


Assuntos
Circulação Sanguínea/efeitos dos fármacos , Ferricianetos/farmacologia , Hemodinâmica/efeitos dos fármacos , Nitroglicerina/farmacologia , Nitroprussiato/farmacologia , Animais , Cães , Halotano , Hipotensão/induzido quimicamente , Fluxo Sanguíneo Regional/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos
18.
Can Anaesth Soc J ; 27(5): 471-4, 1980 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7004597

RESUMO

The interaction of sympathetic blockade and decreased mean arterial pressure on plasma renin activity during surgery was studied in dogs. Plasma renin activity was measured during lumbar laminectomy before and after sympathetic blockade produced by subarachnoid spinal anaesthesia. Plasma renin activity was significantly increased during laminectomy. Twenty minutes after sympathetic blockade there were marked decreases in mean arterial pressure and plasma renin activity; but with mean arterial pressure continuing to decline, plasma renin activity showed moderate increases at 50 minutes after sympathetic blockade. It is concluded that increases in plasma renin activity seen during surgical operations can be attenuated by sympathetic blockade produced by subarachnoid or epidural spinal anaesthesia, although decreases in mean arterial pressure resulting from the sympathetic blockade continue to provide a stimulus for renin secretion.


Assuntos
Bloqueio Nervoso Autônomo , Renina/sangue , Procedimentos Cirúrgicos Operatórios , Sistema Nervoso Simpático/fisiologia , Animais , Pressão Sanguínea , Cães , Laminectomia
19.
Anesthesiology ; 85(4): 787-93, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8873549

RESUMO

BACKGROUND: In supine patients with their heads in flexion, general anesthesia causes posterior displacement of upper airway structures that is associated with airway obstruction, and extension of the head helps restore patency. However, the independent effects of head position, general anesthesia, and muscle paralysis on upper airway structures are not known. METHODS: Lateral radiographs of the neck were taken in supine patients with the head in flexion and extension, during consciousness, and after induction of general anesthesia and muscle paralysis. The following measurements were made distances from the horizontal plane to the epiglottis, the hyold, and the thyroid cartilage to detect anteroposterior displacements; distances from the transverse plane to the hyold and the thyroid cartilage to detect cephalocaudad displacements; and widths of the oropharynx, the laryngeal vestibule, and the laryngeal sinus. RESULTS: With the head in flexion, anesthesia and paralysis compared with the conscious state caused posterior displacement of the epiglottis, narrowing of the oropharynx, and widening of the laryngeal vestibule. With the head in extension, anesthesia and paralysis compared with the conscious state caused anterior displacements of the epiglottis, the hyold, and the thyroid cartilage, narrowing of the oropharynx, and widening of the laryngeal vestibule and the laryngeal sinus. CONCLUSION: Loss of tonic muscular activity due to anesthesia and paralysis results in anteroposterior displacements of the upper airway structures with flexion and extension of the head that are in the same direction as that of the mandible. Anesthesia and paralysis also widen the dimensions of the larynx. These changes might have implications for instrumentation and protection of the airway during general anesthesia or unconsciousness.


Assuntos
Anestesia Geral , Fenômenos Fisiológicos Respiratórios , Idoso , Obstrução das Vias Respiratórias/etiologia , Obstrução das Vias Respiratórias/prevenção & controle , Anestesia Geral/efeitos adversos , Cabeça , Humanos , Masculino , Pessoa de Meia-Idade , Relaxamento Muscular/efeitos dos fármacos , Relaxamento Muscular/fisiologia , Radiografia , Sistema Respiratório/anatomia & histologia , Sistema Respiratório/diagnóstico por imagem , Decúbito Dorsal/fisiologia
20.
Circ Shock ; 6(4): 365-73, 1979.
Artigo em Inglês | MEDLINE | ID: mdl-119586

RESUMO

We studied the effects of two dosage levels of glucagon infusion on systemic hemodynamic and regional blood flow measurements during experimental cardiogenic shock in monkeys. Cardiogenic shock was induced in monkeys by embolization of coronary arteries with glass microspheres. Glucagon 1 microgram/kg/min was infused in five monkeys and five remaining monkeys received glucagon infusion at 10 micrograms/kg/min. Radioactive microsphere technique was used to measure regional blood flows. During cardiogenic shock, there were significant decreases in heart rate, mean arterial pressure, cardiac output and rate of rise of left ventricular pressure and significant increases in total peripheral resistance. Blood flows to the heart, brain, kidney and splanchnic bed were markedly reduced. Neither dosage level of glucagon produced any significant improvement in systemic hemodynamic or regional blood flow values. Glucagon produced only nonsignificant increases in splanchnic blood flow during cardiogenic shock. These findings suggest that glucagon infusions in dosages of 1 microgram/kg/min and 10 micrograms/kg/min do not improve systemic or regional hemodynamic status in severe cardiogenic shock.


Assuntos
Glucagon/farmacologia , Hemodinâmica/efeitos dos fármacos , Choque Cardiogênico/fisiopatologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Glucagon/administração & dosagem , Haplorrinos , Frequência Cardíaca/efeitos dos fármacos , Fígado/irrigação sanguínea , Macaca mulatta , Fluxo Sanguíneo Regional/efeitos dos fármacos , Resistência Vascular
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