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At least 433 records · Page 24Linked to original sources
PubMed2001

Inactivation of infective larvae of Angiostrongylus costaricensis with short time incubations in 1.5% bleach solution, vinegar or saturated cooking salt solution.

Angiostrongylus costaricensis is a nematode parasite of wild rodents in the Americas. Man may become infected accidentally and, sometimes, suffers a very severe abdominal disease. Ingestion of raw vegetables has been proven to be a risk factor for the acquisition of A. costaricensis and, therefore, prophylaxis should include food disinfection. The larvicidal effect of wine vinegar, saturated cooking salt (SS) and a 1.5% bleach solution (BW) were compared with a 1-h-incubation period, at room temperature. Larval viability was tested through inoculation in Swiss mice. Only one out of 560 larvae treated with BW (97.3% of the animals were uninfected) was recovered as an adult worm, while 90/336 and 29/512 larvae treated, respectively, with SS and WV were recovered as adult worms. This larvicidal effect of BW was seen also in incubation times as short as 15 min. In conclusion, the 1.5% bleach solution may be helpful for prophylaxis of human abdominal angiostrongyliasis through disinfection of raw vegetables and unpeeled fruits.

Acetic Acid↗
PubMed2005

A randomized single-blind trial of split-dose PEG-electrolyte solution without dietary restriction compared with whole dose PEG-electrolyte solution with dietary restriction for colonoscopy preparation.

BACKGROUND: Colonoscopy preparation regimens are poorly tolerated, requiring the use of a large volume of an unpalatable solution and diet restriction for adequate cleansing. The aim of this study was to compare the efficacy of two regimens of bowel preparation before colonoscopy: a whole dose of polyethylene glycol electrolyte solution (PEG-E), with diet restriction vs. a split dose with no diet restriction. METHODS: A total of 141 patients (ages 20-84 years, 81 men) were randomly assigned to receive either 4 L PEG-E, along with a liquid diet the day before colonoscopy (Group A) or 2 L PEG-E with a regular diet the day before colonoscopy followed by another 2 L PEG-E on the day of the procedure (Group B). The quality of the preparation was graded by the endoscopist (poor to excellent), who was blinded to the type of preparation. Tolerability of the assigned preparation and adverse effects were recorded by an independent investigator by using a questionnaire administered before colonoscopy. Intra- and interobserver variability was studied by using randomly chosen videotapes of colonoscopies performed as part of the study. RESULTS: There were 73 patients in Group A and 68 patients in Group B. The quality of the preparation was significantly better in Group B ( p = 0.011). The tolerability of the preparation regimen was not different overall between study groups in terms of side effects (except for bloating, which was more frequent in Group B, p = 0.039) or willingness to repeat the preparation. There was a nonsignificant trend toward improved adherence to the assigned preparation in favor of Group B ( p = 0.062). Inter- and intraobserver variability analysis showed good to excellent correlation among endoscopists. CONCLUSIONS: Colonic preparation with split-dose PEG-E and no dietary restriction provides better quality colon cleansing than whole-dose preparation, with no significant impact on patient tolerability and side effects.

Adult↗
PubMed1983

Physico-chemical factors governing partition behaviour of solutes and particles in aqueous polymeric biphasic systems. III. Features of solutes and biological particles detected by the partition technique.

The partition behaviour of human serum albumin and oxyhaemoglobin and several amino acids and small peptides was studied in the aqueous Ficoll-dextran biphasic system as a function of the ionic composition and pH. The partition coefficients of the solutes were expressed in terms of the equivalent number of CH2 groups, nCH2, and the equivalent number of carboxyl groups, m. The physical meaning of these two parameters and of the relationships found between them and pH for the proteins examined are discussed. A correlation was established between the difference in the relative hydrophobicities of the individual phases of various water-organic solvent systems and the interfacial tension, gamma 12, of the systems. It is argued that a relation of a similar type exists for the aqueous polymeric biphasic systems. The possibility of estimating the relative intensity of Van der Waals and hydration interactions of a solute and particle surface by examination of their partitioning in a biphasic system calibrated for the hydrophobic and hydration properties of the phases is discussed.

Amino Acids↗
PubMed1986

Comparison of rice water, rice electrolyte solution, and glucose electrolyte solution in the management of infantile diarrhoea.

150 infants aged under 6 months and admitted to hospital with acute gastroenteritis were treated with rice water (RW), rice-based electrolyte solution (RES), and the glucose electrolyte solution (GES) recommended by the World Health Organisation. Two-thirds of the patients were moderately dehydrated and only 8% had positive stool culture. Vomiting, present in 11%, did not interfere with successful oral rehydration. Before treatment serum electrolytes and other biochemical variables were similar in the three groups. After 48 h of treatment the blood urea nitrogen and serum creatinine were lower (p less than 0.05) in the RW and RES group than in the GES group. Serum potassium was also lower in the RW than in the RES group. RW and RES were superior to GES in reducing the frequency and volume of stool output and in producing weight gain.

Acute Disease↗
PubMed2005

Evidence for lower critical solution behavior in ionic liquid solutions.

Lower critical solution temperatures (LCST)-type of phase diagrams, including the presence of closed loops, have been encountered for the first time in binary and quasi-binary liquid solutions of ionic liquids. Furthermore, the results constitute the first experimental support for the existence of a theoretically postulated, but never encountered, special kind of type VII phase diagram. Two distinct mechanisms are involved in the appearance of demixing upon temperature increase. These findings underlie the presence of specific, oriented interactions between the ionic liquid, 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide, [Cnmim][NTf2], and trichloromethane, as well as aggregation phenomena.

Journal Article↗
PubMed2006

Upper critical solution temperature phase behavior, composition fluctuations, and complex formation in poly (vinyl methyl ether)/D2O solutions: small-angle neutron-scattering experiments and wertheim lattice thermodynamic perturbation theory predictions.

Small-angle neutron-scattering measurements are presented for homogeneous mixtures of poly (methyl vinyl ether) (PVME) and deuterium oxide (D(2)O) at high polymer concentrations and for temperatures lower than the equilibrium melting point of the solvent. The experimental data are analyzed to give values for the second-order compositional derivative of the Gibbs energy and the Ornstein-Zernike correlation length. The experimental data together with earlier SANS data determined at higher temperatures cannot be represented with an extended Flory-Huggins (F-H) interaction function depending on composition and temperatures. The experimental data confirm the existence of a narrow upper critical solution temperature (UCST) miscibility gap at high concentrations in agreement with theoretical predictions of the Wertheim lattice thermodynamic perturbation theory (LTPT). The Wertheim LTPT incorporates the influence of hydrogen bonding and predicts not only the existence of bimodal lower critical solution temperature (LCST) phase behavior but also the occurrence of highly unconventional two narrow adjacent UCST miscibility gaps. Finally, the experimental data do not support the existence of a stable molecular complex at the investigated temperatures and compositions. Even at the lowest investigated temperature, the energy required to induce typical Ornstein-Zernike-like concentration fluctuations is smaller than the thermal energy. Also, in this case, the Wertheim LTPT provides a theoretical basis to understand the formation of polymer solvent associations in PVME/water.

Journal Article↗
PubMed2006

Thermal lens spectroscopy in cryogenic solutions: Analysis and comparison of intensities in CH4-N2 and CH4-Ar liquid solutions.

The C-H (Delta upsilon = 6) absorption spectrum of methane has been obtained in liquid nitrogen and argon solutions using thermal lens spectroscopy. Mathematical models for continuous and periodic excitation were used to describe the concentration dependence of thermal lens intensities. Better fitting of the experimental results was accomplished by taking into account the periodic nature of the excitation. Comparison of thermal lens intensities in nitrogen and argon allowed calculation of relative enhancement factors. In dilute solutions, the intensity in liquid nitrogen was 1.39 +/- 0.08 times higher than that in argon. The literature estimation of this ratio is 1.49 +/- 0.61. In contrast to the estimated value, our result confidently shows actual variation in enhancement factors. This article not only shows the applicability of thermal lensing to cryosamples but also demonstrates that accurate measurements at low temperature are possible.

Journal Article↗
PubMed2005

Tetrabutylammonium alkyl carboxylate surfactants in aqueous solution: self-association behavior, solution nanostructure, and comparison with tetrabutylammonium alkyl sulfate surfactants.

A series of long and ultralong chain tetrabutylammonium alkyl carboxylate (TBACm, TBA = tetrabutylammonium ion; Cm = carboxylate ion C(m-1)H(2)(m-1)CO(2)(-) of total carbon number m) surfactants have been obtained by direct neutralization of the fatty acids with m = 12, 14, 18, 22, and 24 by tetrabutylammonium hydroxide. Time-resolved fluorescence quenching has been used to determine the micelle aggregation number (N) of the surfactants with m = 12, 14, and 18 in the temperature range 10-50 degrees C and of the surfactants with m = 22 and 24 in the temperature range 25-60 degrees C. In all instances the values of N were well below those that can be calculated for the maximum spherical micelle formed by surfactants with the same alkyl chain as the investigated surfactants on the basis of the oil drop model for the micelle core. The microstructure of selected solutions of TBAC22 was examined using transmission electron microscopy at cryogenic temperature and compared to the microstructure of solutions of TBA dodecyl and tetradecyl sulfates. These observations generally confirmed the findings of TRFQ. The self-association behavior of these anionic surfactants with TBA counterions is explained on the basis of the large size and the hydrophobicity of the tetrabutylammonium ions. The important differences in behavior that have been evidenced between tetrabutylammonium alkyl carboxylates and alkyl sulfates are discussed in terms of differences in distribution of the surfactant electrical charge on the headgroup and alkyl chain predicted by quantum chemical calculations (Langmuir 1999, 15, 7546).

Journal Article↗
PubMed1991

"On-off" thermocontrol of solute transport. II. Solute release from thermosensitive hydrogels.

Poly(N-isopropylacrylamide) (NIPAAm)/polytetramethylene ether glycol (PTMEG) interpenetrating polymer networks (IPNs) were synthesized and their feasibility as thermosensitive hydrogels for drug release was investigated. The release of indomethacin incorporated into these matrices showed pulsatile patterns in response to temperature changes and was sensitive to a few degrees of temperature fluctuation. The temperature inducing on-off release deviated from the gel collapse temperature of unloaded gel, possibly because of solute effects on network properties. The lag time and release profile of indomethacin in the low-temperature region (on process) of each temperature cycle were affected by the gel composition and applied temperature. The results of this study demonstrate that solute release can be regulated by rapid deswelling of the surface of the gels in response to temperature.

Drug Carriers↗
PubMed2002

AgInZn7S9 solid solution photocatalyst for H2 evolution from aqueous solutions under visible light irradiation.

AgInZn7S9 with a 2.3 eV band gap, which was a solid solution of AgInS2 and ZnS semiconductors, showed photocatalytic activity for H2 evolution from an aqueous solution containing sacrificial reagents SO3(2-) and S2- under visible light irradiation (lambda > 420 nm) even without a Pt cocatalyst, and loading of the Pt cocatalyst improved the photocatalytic activity.

Journal Article↗
PubMed2005

Kinetics of hydrolysis of 4-methoxyphenyl-2,2-dichloroethanoate in binary water-cosolvent mixtures; the role of solvent activity and solute-solute interactions.

Rate constants are reported for the pH-independent hydrolysis of 4-methoxyphenyl-2,2-dichloroethanoate in aqueous solution as a function of the concentration of added cyanomethane (acetonitrile), polyethylene glycol (PEG 400) and tetrahydrofuran (THF). The concentration of water was varied between ca. 25 and 55.5 M. It was found that the variation in water activity yields only a minor contribution to the observed variation in rate constants. Interestingly, for both cyanomethane and PEG 400 log(k) varies approximately linearly with the molar concentration of water. Medium effects in highly aqueous solutions ([H(2)O] > 50 M) of ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-2-propanol have also been determined. Unexpectedly, in this concentration range the alcohols induce significantly smaller effects per unit volume than cyanomethane. The present results are discussed in terms of pairwise interaction parameters. Isobaric activation parameters have been determined and reveal remarkable differences in the nature of the induced medium effects.

Journal Article↗
PubMed2000

The survival, function, and hemolysis of human RBCs stored at 4 degrees C in additive solution (AS-1, AS-3, or AS-5) for 42 days and then biochemically modified, frozen, thawed, washed, and stored at 4 degrees C in sodium chloride and glucose solution for 24 hours.

BACKGROUND: A study was done to assess the quality of RBCs stored at 4 degrees C in AS-1, AS-3, or AS-5 for 42 days before biochemical modification and freezing. STUDY DESIGN AND METHODS: RBCs were stored at 4 degrees C for 42 days in AS-1, AS-3, or AS-5 and then biochemically modified with pyruvate, inosine, phosphate, and adenine solution (Rejuvesol), frozen with 40-percent (wt/vol) glycerol, and stored at -80 degrees C for at least 2 months. The RBCs were deglycerolized by the use of a cell washer (Haemonetics 115), and stored for 24 hours at 4 degrees C in a 0.9-percent sodium chloride and 0.2-percent glucose solution before the autologous transfusion. RESULTS: The mean freeze-thaw-wash recovery process produced RBC recovery values of 85 percent, with the mean 24-hour posttransfusion survival at 75 percent, and the mean index of therapeutic effectiveness at 64 percent for the RBCs stored at 4 degrees C in AS-1, AS-3, or AS-5 for 42 days before biochemical modification and freezing. All the units exhibited normal or slightly higher than normal 2,3 DPG levels after deglycerolization and postwash storage at 4 degrees C for 24 hours. CONCLUSION: RBCs stored in AS-1, AS-3, or AS-5 at 4 degrees C for 42 days and then biochemically modified with pyruvate, inosine, phosphate, and adenine and glycerolized, frozen, washed, and stored at 4 degrees C for 24 hours before autologous transfusion had acceptable in vitro and in vivo measurements.

Adenine↗
PubMed2005

Determination of fexofenadine in tablets by capillary electrophoresis in free solution and in solution with cyclodextrins as analyte carriers.

Capillary electrophoresis (CE) methods for the determination of fexofenadine (FEX) in commercial pharmaceuticals were developed. It was demonstrated that FEX could be effectively analyzed in free solution cationic CE at low pH. Another analytical approach studied was based on cyclodextrin (CD) modified CE where highly charged CD derivatives served as analyte carriers. In this way, the separation range was spread to physiological pH region and a CE analysis of FEX, present actually in its zwitterionic form, could be accomplished. Several parameters affecting the separations were studied, including the type and concentration of carrier ion, counterion, analyte carrier, and pH of the buffer. The methods based on the free solution CE and CD-modified CE were compared each other, validated, and applied for the determination of FEX in tablets.

Anti-Allergic Agents↗
PubMed1985

Interaction of radiation-generated radicals with myoglobin in aqueous solution. III. Effects of oxygen and catalase on the product distribution in solutions of ferrimyoglobin containing N2O.

The gamma-radiolysis of aqueous solutions of ferrimyoglobin in the presence of N2O at pH 7.3 has been examined as a function of added catalase and oxygen. Changes in the nature of the heme group have been monitored by visible absorption spectrophotometry and analysed quantitatively by a multiple wavelength method based on Beer's Law. Simple chemical analyses have been used to confirm qualitative identification of the product derivatives. As observed previously, the ferriheme is reduced by indirect globin-mediated action initiated by OH/H. The yield of reduced product decreases as [O2] increases. Conversion to ferrimyoglobin through the participation of H2O2 derived from irradiated water and from protein-mediated processes in oxygenated solution, is eliminated by the presence of catalase. Formation of a hemichrome form of ferrimyoglobin is apparent at higher doses in the presence of O2. These results demonstrate that oxygen plays an important role in controlling the nature and extent of redox that manifests ultimately on the heme group of ferrimyoglobin as a result of the initial interaction of OH/H.

Catalase↗
PubMed2005

An open-label randomized trial comparing itraconazole oral solution with fluconazole oral solution for primary prophylaxis of fungal infections in patients with haematological malignancy and profound neutropenia.

OBJECTIVES: This trial studied the efficacy and safety of itraconazole and fluconazole in the prevention of invasive fungal infections in neutropenic patients with haematological malignancies. PATIENTS AND METHODS: An 8 week, open-label, randomized, parallel-group, multicentre trial comparing itraconazole oral solution (2.5 mg/kg twice daily; N=248) with fluconazole oral solution or capsules (400 mg daily; N=246) in 494 patients with anticipated profound neutropenia (i.e. neutrophil count expected to be <500 cells/mm3 for at least 10 days) from tertiary care centres. RESULTS: Invasive fungal infections were reported for 4 out of 248 patients (1.6%) in the itraconazole group and 5 out of 246 patients (2.0%) in the fluconazole group. Invasive Aspergillus infections were proven for 2 out of 248 patients (0.8%) in the itraconazole group and 3 out of 246 patients (1.2%) in the fluconazole group. For both the ITT and profoundly neutropenic populations, no differences were detected between treatment groups in proven or suspected invasive fungal infections or other endpoints. The mortality rates owing to proven invasive fungal infections were 2 out of 248 patients (0.8%) for the itraconazole group and 3 out of 246 patients (1.2%) for the fluconazole group. There was also no difference between treatment groups in the number of patients who recovered from neutropenia or in the duration of neutropenia. More discontinuation of drug intake owing to nausea and more hypokalaemia occurred in the itraconazole group, other adverse events and the total number of adverse events were similar in both groups. CONCLUSIONS: In this study there were no differences in the efficacy and safety of itraconazole and fluconazole prophylaxis in neutropenic patients with haematological malignancies.

Adolescent↗