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1.
Poult Sci ; 96(8): 2839-2844, 2017 Aug 01.
Article in English | MEDLINE | ID: mdl-28520947

ABSTRACT

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.


Subject(s)
Food Microbiology , Food Packaging/methods , Food Preservation/methods , Meat/analysis , Spices/analysis , Animals , Chickens , Cinnamomum zeylanicum/chemistry , Syzygium/chemistry
2.
Int J Biol Macromol ; 83: 385-95, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26592701

ABSTRACT

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.


Subject(s)
Cellulose/chemistry , Starch/chemistry , Mechanical Phenomena , Particle Size , Seeds/chemistry , Tamarindus/chemistry , Temperature
3.
J Appl Microbiol ; 119(6): 1613-23, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26274630

ABSTRACT

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.


Subject(s)
Anti-Bacterial Agents , Food Preservation/methods , Oils, Volatile , Red Meat/microbiology , Starch , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Cattle , Oils, Volatile/chemistry , Oils, Volatile/pharmacology , Spices , Starch/chemistry , Starch/pharmacology , Zea mays
4.
Ecotoxicol Environ Saf ; 121: 180-5, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25866205

ABSTRACT

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.


Subject(s)
Oxygen/analysis , Sewage/microbiology , Sonication/methods , Waste Disposal, Fluid/methods , Wastewater/microbiology , Aerobiosis , Biomass , Biomechanical Phenomena , Equipment Design , Microbial Consortia , Sewage/chemistry , Sonication/instrumentation , Waste Disposal, Fluid/instrumentation
5.
Curr Microbiol ; 70(6): 898-906, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25842173

ABSTRACT

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.


Subject(s)
Bacillus cereus/metabolism , Bacteriological Techniques/methods , Colorimetry/methods , Enterobacteriaceae/metabolism , High-Throughput Screening Assays/methods , Phenol/metabolism , Bacillus cereus/classification , Bacillus cereus/genetics , Bacillus cereus/isolation & purification , Biotransformation , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Enterobacteriaceae/classification , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Molecular Sequence Data , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Time Factors
6.
Environ Technol ; 35(17-20): 2194-203, 2014.
Article in English | MEDLINE | ID: mdl-25145172

ABSTRACT

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.


Subject(s)
Bacillus subtilis/metabolism , Biodegradation, Environmental , Bioelectric Energy Sources , Bioreactors/microbiology , Petroleum/metabolism , Sodium Chloride/isolation & purification , Bacillus subtilis/isolation & purification , Gas Chromatography-Mass Spectrometry , Hydrogen-Ion Concentration , Petroleum/analysis , Sodium Chloride/chemistry , Temperature
7.
Int J Food Microbiol ; 171: 32-40, 2014 Feb 03.
Article in English | MEDLINE | ID: mdl-24308943

ABSTRACT

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.


Subject(s)
Anti-Infective Agents/pharmacology , Antioxidants/pharmacology , Food Microbiology , Food Preservation/standards , Meat/microbiology , Plant Extracts/pharmacology , Spices , Animals , Bacteria/drug effects , Chickens , Flavonoids/analysis , Microbial Sensitivity Tests , Origanum/chemistry , Phenols/analysis , Thiobarbituric Acid Reactive Substances
8.
Carbohydr Polym ; 98(1): 89-94, 2013 Oct 15.
Article in English | MEDLINE | ID: mdl-23987320

ABSTRACT

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.


Subject(s)
Plant Mucilage/isolation & purification , Tissue Engineering , Abelmoschus/chemistry , Acetone/chemistry , Chemical Fractionation , Methanol/chemistry , Plant Mucilage/chemistry , Solvents/chemistry , Temperature
9.
J Hazard Mater ; 179(1-3): 318-22, 2010 Jul 15.
Article in English | MEDLINE | ID: mdl-20359816

ABSTRACT

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.


Subject(s)
Industrial Waste/analysis , Manihot/chemistry , Soil/analysis , Animals , Carbon/analysis , Cattle , Humidity , Hydrogen-Ion Concentration , India , Manure/analysis , Nitrogen/analysis , Nutritional Status , Oligochaeta , Poultry , Temperature
10.
J Cardiothorac Vasc Anesth ; 14(2): 136-9, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10794330

ABSTRACT

OBJECTIVE: To perform three-dimensional surface reconstructions to provide spatial delineations of a normal and an aneurysmatic left ventricle, using transesophageal echocardiography. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Eight patients in cardiogenic shock admitted to the intensive care unit and two patients undergoing surgery with general anesthesia. INTERVENTIONS: Using a multiplane transesophageal echocardiography probe, nine echocardiographic cross-sectional images of the heart at approximately 20 degrees angular increments were obtained from midesophageal level in each patient for three-dimensional surface reconstructions. Multiple determinations of cardiac output using the thermodilution principle were also made in each patient to verify the accuracy of three-dimensional data sets. MEASUREMENTS AND MAIN RESULTS: End-diastolic and end-systolic volumes were determined from three-dimensional data sets using the disc-summation method. Stroke volume was derived as the difference between end-diastolic and end-systolic volumes. Stroke volume was also calculated from thermodilution cardiac output measurements and heart rate. Correlation and limits of agreement between stroke volumes derived by the two methods were determined. Three-dimensional wire-frame models of a normal and an aneurysmatic left ventricle at end-systole were constructed from the nine echocardiographic cross-sectional images. Correlation coefficient between stroke volume derived from three-dimensional data sets using the disc-summation method and that measured by the thermodilution method was 0.91 (p < 0.001). Wire-frame models reveal a normal symmetric cavity and an aneurysmal cavity in sharp relief. CONCLUSIONS: Three-dimensional surface reconstruction can be performed from multiple cross-sectional images obtained using an unmodified commercially available multiplane transesophageal echocardiography probe, to reveal the left ventricular cavity in sharp relief. High correlation between stroke volume calculated from three-dimensional data sets and that measured by the thermodilution method attests to the accuracy of the three-dimensional data sets.


Subject(s)
Echocardiography, Transesophageal , Heart Aneurysm/diagnostic imaging , Heart Aneurysm/surgery , Myocardial Revascularization/instrumentation , Adult , Anesthesia, General , Heart Ventricles/surgery , Hemodynamics/physiology , Humans , Image Processing, Computer-Assisted , Male , Prospective Studies , Shock, Cardiogenic/diagnostic imaging , Shock, Cardiogenic/surgery , Stroke Volume/physiology
11.
Am Heart J ; 139(3): 378-87, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10689248

ABSTRACT

OBJECTIVES: To compare mitral annular shape and motion throughout the cardiac cycle in patients with normal hearts versus those with functional mitral regurgitation (FMR). BACKGROUND: The causes of mitral regurgitation without valvular disease are unclear, but the condition is associated with changes in annular shape and dynamics. Three-dimensional (3D) imaging provides a more comprehensive view of annular structure and allows accurate reconstructions at high spatial and temporal resolution. METHODS: Nine normal subjects and 8 patients with FMR undergoing surgery underwent rotationally scanned transesophageal echocardiography. At every video frame of 1 sinus beat, the mitral annulus was manually traced and reconstructed in 3D by Fourier series. Annular projected area, nonplanarity, eccentricity, perimeter length, and interpeak and intervalley spans were determined at 10 time points in systole and 10 points in diastole. RESULTS: The mitral annulus in patients with FMR had a larger area, perimeter, and interpeak span than in normal subjects (P <.001 for all). At mid-systole in normal annuli, area and perimeter reach a minimum, nonplanarity is greatest, and projected shape is least circular. These cyclic variations were not significant in patients with FMR. Annular area change closely paralleled perimeter change in all patients (mean r = 0.96 +/- 0.07). CONCLUSIONS: FMR is associated with annular dilation and reduced cyclic variation in annular shape and area. Normal mitral valve function may depend on normal annular 3D shape and dimensions as well as annular plasticity. These observations may have implications for design and selection of mitral annular prostheses.


Subject(s)
Mitral Valve Insufficiency/diagnostic imaging , Mitral Valve/anatomy & histology , Mitral Valve/diagnostic imaging , Adult , Aged , Diastole/physiology , Echocardiography, Three-Dimensional , Echocardiography, Transesophageal , Female , Fourier Analysis , Humans , Image Processing, Computer-Assisted , Intraoperative Period , Male , Middle Aged , Mitral Valve/physiology , Mitral Valve Insufficiency/surgery , Observer Variation , Regression Analysis , Severity of Illness Index , Systole/physiology
12.
Crit Care Med ; 27(4): 821-4, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10321676

ABSTRACT

OBJECTIVE: To determine whether an advanced cardiac life support (ACLS) computer simulation program improves retention of ACLS guidelines more effectively than textbook review. DESIGN: Randomized, controlled trial. SETTING: Academic medical center. PARTICIPANTS: Forty-five anesthesia residents and faculty tested 10 to 11 months after ACLS provider course training. INTERVENTION: Participants were randomized and asked to prepare for a mock resuscitation (Mega Code) with either textbooks or a computerized ACLS simulation program. MAIN OUTCOME MEASURE: Performance on a standardized Mega Code examination that required application of supraventricular tachycardia, ventricular fibrillation, and second-degree Type II atrioventricular block algorithms. Mega Code sessions were administered by an instructor who was blinded as to the subject group. The sessions were videotaped and scored by two evaluators who also were blinded as to the subject group. RESULTS: Participants who used the ACLS simulation program scored significantly higher (mean 34.9 +/- 5.0 [SD] of 47 possible points) than participants who reviewed using a textbook (29.2 +/- 4.9); p < .001. Pass-fail rates for the algorithms were also higher for the group that reviewed with the simulator (mean 2.5 +/- 0.5 of 3 possible passes) than the group that used the textbook (1.6 +/- 1.0); p = .001. CONCLUSIONS: Use of a computerized ACLS simulation program improves retention of ACLS guidelines better than textbook review.


Subject(s)
Cardiopulmonary Resuscitation/education , Computer Simulation , Computer-Assisted Instruction/methods , Education, Medical, Continuing/methods , Internship and Residency/standards , Practice Guidelines as Topic , Textbooks as Topic , Academic Medical Centers , Algorithms , Anesthesiology/education , Clinical Competence/standards , Humans , Single-Blind Method , Washington
13.
Anesthesiology ; 88(5): 1330-9, 1998 May.
Article in English | MEDLINE | ID: mdl-9605694

ABSTRACT

BACKGROUND: The aim of this study was to identify the mechanisms by which halothane and isoflurane change the myocardial beta-adrenergic signal transduction pathway. METHODS: The authors investigated the influence of volatile anesthetics on the isometric force of contraction of rat papillary muscles. Concentration-response curves for isoproterenol and epinephrine were studied under control conditions and in the presence of halothane or isoflurane. In radioligand receptor-binding studies, the beta-adrenoceptor affinities for isoproterenol and epinephrine were investigated with and without guanosine triphosphate. In addition, the isoproterenol-induced cyclic adenosine monophosphate accumulations in viable cardiomyocytes in the absence and in the presence of halothane were determined by radioimmunoassays. RESULTS: The half-maximal positive inotropic effect of isoproterenol was reached at a half-maximal effective concentration (EC50 value) of 68 nM (33-141 nM; n = 10). A minimum alveolar concentration of 1.3 halothane reduced the positive inotropic potency of isoproterenol (EC50 = 158 nM [118-214 nM; n = 10; P < 0.01 vs. control]), whereas isoflurane did not changed it. This observation held true when the force of contraction was stimulated with epinephrine. Halothane (1.3 minimum alveolar concentration) depressed beta-adrenoceptor high-affinity binding and beta-adrenoceptor agonist affinity in radioligand binding assays, an effect not seen with isoflurane. Halothane shifted the intracellular cyclic adenosine monophosphate response curve of isoproterenol to the right. CONCLUSION: Halothane, but not isoflurane, impairs the beta-adrenergic responsiveness in rat myocardium by reducing the agonist affinity of the beta-adrenoceptors.


Subject(s)
Anesthetics, Inhalation/pharmacology , Halothane/pharmacology , Isoflurane/pharmacology , Myocardial Contraction/drug effects , Myocardium/metabolism , Receptors, Adrenergic, beta/drug effects , Adrenergic beta-Agonists/pharmacology , Animals , Cyclic AMP/metabolism , Dose-Response Relationship, Drug , Drug Interactions , Female , Heart/drug effects , Heart/physiology , In Vitro Techniques , Isoproterenol/pharmacology , Radioligand Assay , Rats , Rats, Sprague-Dawley , Receptors, Adrenergic, beta/metabolism , Signal Transduction/drug effects
15.
Health Care Financ Rev ; 19(1): 161-200, 1997.
Article in English | MEDLINE | ID: mdl-10179997

ABSTRACT

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.


Subject(s)
Health Expenditures/statistics & numerical data , Drug Prescriptions/economics , Economics , Health Expenditures/trends , Home Care Services/economics , Humans , Insurance, Health/economics , Managed Care Programs/economics , Medicare/statistics & numerical data , Nursing Homes/economics , United States
16.
Anesthesiology ; 85(4): 787-93, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8873549

ABSTRACT

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.


Subject(s)
Anesthesia, General , Respiratory Physiological Phenomena , Aged , Airway Obstruction/etiology , Airway Obstruction/prevention & control , Anesthesia, General/adverse effects , Head , Humans , Male , Middle Aged , Muscle Relaxation/drug effects , Muscle Relaxation/physiology , Radiography , Respiratory System/anatomy & histology , Respiratory System/diagnostic imaging , Supine Position/physiology
17.
Eur Heart J ; 17(8): 1279-88, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8869871

ABSTRACT

BACKGROUND: Biplane angiographic and transthoracic echocardiographic volume calculations have shown to be sufficiently reliable in symmetric hearts; however, they are unreliable in the presence of aneurysmatic distortions. Multiplane transoesophageal echocardiography offers unobstructed cross-sectional views of the heart from one stable transducer position with the potential of imaging irregular cavity forms more accurately. It was the purpose of this in vitro study to compare the precision of multiplanar transoesophageal echocardiography to that of biplane angiography in determining left ventricular volumes, especially in aneurysmatic models. METHODS: Seven silicon rubber models of the left ventricle from post-mortem specimens (four with aneurysms) were filled with 30 different volumes (range 153-256 ml, 197 +/- 30 ml). Echocardiographic cross-sections (20 degree rotational steps) were obtained from different transducer positions, utilizing a multiplanar probe with a central rotational axis. Volumes were calculated using the disc-summation method. For comparison the same volumes were determined by standard biplane angiography. The minimum number of echo cross-section necessary to optimize precision was analysed by calculating volumes for each increasing equidistant rotational step. RESULTS: Linear correlation between measured volume using a multiplanar transoesophageal echoprobe and true volume was high (r = 0.97) and significantly better than for biplane angiography (r = 0.88; P < 0.001). Measurement bias and imprecision were also significantly lower with multiplanar echocardiography than with biplane angiography (3.9 +/- 7.1% vs 11.1 +/- 15.4%, and 2.0 +/- 3.7% vs 5.9 +/- 8.3%; P < 0.001). Precision of biplane angiographic volume measurements was significantly influenced by the presence of aneurysmatic distortions. Multiplanar echo volumes, however, were not influenced by left ventricular geometry and transducer positions. Nine echo cross-sections provided optimal precision. CONCLUSIONS: Three-dimensional echocardiographic volume calculations using a multiplanar transoesophageal echoprobe and the disc-summation method provide precise measurements unaffected by left ventricular geometry and transducer position in an in vitro setting. Standard biplane angiography is significantly less precise.


Subject(s)
Angiography/methods , Echocardiography, Transesophageal/methods , Heart Aneurysm/physiopathology , Ventricular Dysfunction, Left/physiopathology , Heart Aneurysm/diagnostic imaging , Humans , In Vitro Techniques , Models, Anatomic , Regression Analysis , Stroke Volume/physiology , Ventricular Dysfunction, Left/diagnostic imaging
19.
Anesth Analg ; 81(1): 52-6, 1995 Jul.
Article in English | MEDLINE | ID: mdl-7598282

ABSTRACT

Based on studies using skinned myocardial fibers from animals, it has been postulated that one of the major mechanisms by which halothane depresses myocardial contractility is by decreasing the Ca2+ content of the sarcoplasmic reticulum (SR). In this study we examined, in skinned human myocardial fibers, the effects of halothane on Ca(2+)-activated tension development of the contractile proteins and Ca2+ uptake and release by the SR. Left ventricular muscle samples obtained from patients undergoing aortocoronary bypass operations were mechanically skinned and immersed in test solutions equilibrated with N2 and halothane preceded and followed by immersion in control solution (no halothane). To study Ca(2+)-activated tension development of the contractile proteins, free Ca2+ concentrations in the bathing solutions were buffered by EGTA. To study Ca2+ uptake and release by the SR, Ca2+ was loaded into the SR and released with caffeine and the resulting tension transients were measured. Halothane (1%-3%) depressed maximum Ca(2+)-activated tensions (pCa = -log[Ca2+](M) = 3.8) by 5% for each 1% increase in concentration. Tensions generated by submaximum Ca2+ concentrations expressed as a percentage of maximum tension were not significantly decreased by halothane except at 3%. Halothane decreased Ca2+ uptake (IC50 = 1.7%), and increased (by approximately 50%) Ca2+ release by the SR. We conclude that decreased activation of the contractile proteins and Ca2+ uptake by the SR can both contribute to the myocardial depression produced by halothane. Of these, decreased Ca2+ uptake by the SR is probably a major mechanism for halothane depression of myocardium.


Subject(s)
Calcium/metabolism , Contractile Proteins/drug effects , Halothane/pharmacology , Muscle Fibers, Skeletal/metabolism , Myocardium/metabolism , Sarcoplasmic Reticulum/drug effects , Animals , Buffers , Caffeine/pharmacology , Calcium/pharmacokinetics , Contractile Proteins/metabolism , Dose-Response Relationship, Drug , Egtazic Acid , Halothane/administration & dosage , Heart Ventricles , Humans , Myocardial Contraction/drug effects , Nitrogen/pharmacology , Rabbits , Sarcoplasmic Reticulum/metabolism
20.
Anesth Analg ; 80(2): 384-7, 1995 Feb.
Article in English | MEDLINE | ID: mdl-7818129

ABSTRACT

A fiberoptic bronchoscope is used to facilitate tracheal intubation in cases of difficult direct laryngoscopy. Occasionally, difficulty is encountered in advancing the endotracheal tube after the fiberoptic bronchoscope has been introduced into the trachea. This study tested the feasibility of providing jet ventilation through the suction channel of the fiberoptic bronchoscope as an interim measure under those or similar circumstances. Three commercial models of fiberoptic bronchoscopes with suction channels of 1.2-, 1.5-, and 2-mm diameter, respectively, were tested in a mechanical test lung at varying compliances and resistances using a jet injector connected to an oxygen source at 50 psi. The fiberoptic bronchoscope with the 2-mm suction channel was also studied in seven adult patients who were anesthetized and paralyzed. Jet ventilation was manually performed at the rate of 12/min for 10 min. In the mechanical test lung, the tidal volumes with 1.2-, 1.5-, and 2-mm suction channels were as follows: 280 mL, 490 mL, and 880 mL, respectively, at a compliance of 50 mL/cm H2O and normal resistance; 260 mL, 470 mL, and 820 mL, respectively, at a compliance of 50 mL/cm H2O and high resistance to simulate bronchospasm; 130 mL, 270 mL, and 890 mL, respectively, at a compliance of 20 mL/cm H2O and normal resistance; 120 mL, 220 mL, and 810 mL, respectively, at a compliance of 20 mL/cm H2O and high resistance. In anesthetized, paralyzed patients, oxygen saturation was 96% or more throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Bronchoscopes , High-Frequency Jet Ventilation/instrumentation , Adult , Aged , Carbon Dioxide/blood , Coronary Artery Bypass , Feasibility Studies , Fiber Optic Technology , Humans , Lung Compliance , Middle Aged , Partial Pressure , Thoracotomy
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