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At least 1,009 records · Page 56Linked to original sources
PubMed1988

[A titration method of determining the acidity of opaque gastric juice in emergency surgery].

The data presented show great practical significance of titration methods of the investigation of gastric secretion. 220 comparative determinations of acidity of the gastric juice have shown the presence of admixtures of mucus, blood and bile in the gastric content to overstate the indices of the colorimetric titration method without a practical effect on the electrometric one which is known to be more precise.

Colorimetry↗
PubMed1986

Assessment of IgE-mediated sensitivity during immunotherapy: comparison of the RAST with and without adsorption of IgG to titrated prick skin tests.

The effect of specific IgG induced by allergy immunotherapy on specific IgE binding in the RAST was assessed by removal of the IgG with staphylococcus protein A bound to Sepharose. In sera from those patients with the highest titers of specific IgG, RAST binding was increased 8% following adsorption of the post-immunotherapy sera while in sera obtained from the same patients before immunotherapy adsorption increased binding only 3%. The effect of allergy immunotherapy on the titrated prick skin test was compared to the effect on the RAST to the same allergen. In nine patients who received the highest dose of grass extract, the area of the titrated prick skin tests was reduced following immunotherapy by 75%. Staphylococcus protein-A adsorption of sera from these patients drawn before immunotherapy resulted in an increase in RAST binding of 2.7% compared to an increase of 6% in sera obtained after immunotherapy, suggesting suppression of RAST binding of only 3% by specific IgG. It is concluded that RAST levels are affected less than prick skin tests by the immunologic response to allergy immunotherapy. Some interference in RAST binding is produced by specific IgG antibody in high titers, but for many critical purposes the degree of interference is not significant.

Absorption↗
PubMed1986

Treatment of hypertensive emergencies and urgencies with oral clonidine loading and titration. A review.

Oral clonidine hydrochloride rapid titration or loading is a safe, effective method to control severe elevations of blood pressure in hypertensive crisis in many clinical situations. An initial oral dose of 0.1 to 0.2 mg of clonidine hydrochloride followed by hourly doses of 0.05 or 0.1 mg until goal blood pressure is attained that does not reduce perfusion to critical organs, or a total of 0.7 mg is given, will achieve a significant reduction in blood pressure in 93% of patients. A smooth, rapid, predictable reduction in blood pressure, patient comfort, lower overall cost, reduced requirement for close observation, intravenous lines, and hospitalization, and a small incidence of clinically significant side effects make oral clonidine rapid titration an attractive oral antihypertensive agent for patients with hypertensive urgencies and in some carefully selected patients with hypertensive emergencies. Immediate outpatient follow-up within 24 hours is mandatory in all patients who are not hospitalized to adjust the dose of antihypertensive medications.

Blood Pressure↗
PubMed1979

Physical chemical and technical limitations to intragastric titration.

Intragastric titration, introduced in 1973, has become more popular than in the past and is being applied to the study of gastric secretion under a variety of conditions using NaHCO3 and NaOH as titrant. Physical chemical and technical considerations point to limitations on the conditions under which quantitative results can be obtained. At low end point pH, the limitation relates to volume expansion by secretions and titrant. Errors increase exponentially so that at pH 1.11 a 66% error is incurred and at pH 0.93 a 100% error would result. Neutralization with NaHCO3 poses limitations when CO2 is not effectively removed from the stomach, and even at pH 5.5 errors as large as 20% can be incurred. Errors increase markedly at high end point pH. Use of end point pHs above the pKa' of carbonic acid could lead to large amounts of factitious acid secretion if the intralumental contents are in equilibrium with CO2 entering from the gastric wall. There seems no reason that intragastric titration should not be a useful and quantitative method within the end point pH range of 4.0--4.5. In vivo validation of each experimental condition is needed.

Bicarbonates↗
PubMed1987

Content uniformity test of tablets by nonaqueous titration method.

For the Content uniformity test (CUT) of tablets where the active drug behaves in a nonaqueous medium as a base a very simple method was developed. This method is based on the extraction of the active drug from the tablet into anhydrous acetic acid and direct titration of the solute with HClO4 (0.1 or 0.05 mol/l solution in anhydrous acetic acid). The course of the titration is followed potentiometrically with a glass and calomel electrode coupled and recorded automatically with a suitable registration potentiometer. The method was successfully applied to samples of commercial tablets containing the following drugs: codeine phosphate, embramine, ephedrine, ethylmorphine, pyridoxine, thiamine and tolazoline, all as hydrochlorides. It can be used also for several other drugs.

Alkaloids↗
PubMed1985

Shock titration in the rhesus monkey: effects of opiate and nonopiate analgesics.

This study evaluated the antinociceptive effects of several opiate and nonopiate analgesics in the rhesus monkey using a discrete trial shock titration paradigm. Morphine sulfate (1, 5 and 10 mg/kg i.m.) and codeine sulfate (3, 10 and 30 mg/kg i.m.) produced a significant and dose-dependent increase in mean shock threshold that was not accompanied by a significant increase in mean response latency. The mean number of shocks terminated was significantly decreased at the highest dose of each opiate. Aspirin (100 and 300 mg/kg p.o.) or ibuprofen (200 mg/kg p.o.) did not significantly increase mean shock threshold or mean response latency or decrease mean number of shocks terminated. However, 6 mg/kg i.m. of 4,5,6,7-tetrahydroisoxazolo [5,4-c]pyridin-3-ol produced a significant increase in mean shock threshold and mean response latency with no significant effect on mean number of shocks terminated. The absence of any effects of a 2-mg/kg dose of 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol and the severe side effects produced by 10 mg/kg prevented determination of its dose-response relationship. Diazepam (0.5, 2 and 8 mg/kg i.m.) produced a significant, dose-dependent increase in mean shock threshold and a significant increase in mean response latency with no consistent or significant effect on mean number of shocks terminated. Doses of 2 and 8 mg/kg of diazepam also produced signs of ataxia. These results suggest that the discrete trial shock titration paradigm is suitable for demonstration of the antinociceptive effects of opiate and certain nonopiate analgesics, but not nonsteroidal anti-inflammatory analgesics in the rhesus monkey.

Administration, Oral↗
PubMedDate not supplied

[Titration of the antibodies to the Crimean hemorrhagic fever virus in a drop of the cell suspension from infected tissue cultures by means of indirect immunofluorescence].

A comparatively simple method has been developed and tested for the detection and titration of antibody to Crimean hemorrhagic fever virus (CHF) by indirect immunofluorescence on slides with previously prepared acetone-inactivated virus in drops of cell suspension from infected BHK-21 and 6619 cell cultures. The antibody titers determined by the indirect immunofluorescence procedures were 4- and 8-fold higher than those determined by the complement-fixation test. This opens the possibility of using non-infectious antigens of cell suspensions for detection or titration by the FA procedure of antibody to CHF virus which may be of importance to diagnostic laboratories which have no conditions for work with live virus.

Antibodies, Viral↗
PubMed1979

Sequential titration of bovine lung and serum antibodies after parenteral or pulmonary inoculation with Pasteurella haemolytica.

Calves were vaccinated by intrabronchial or subcutaneous injection of formalinized Pasteurella haemolytica. Antibody in serum, nasal washings, and bronchoalveolar washings was titrated sequentially before and after calves were vaccinated and then challenge exposed with live homologous bacteria. Bronchoalveolar washings were collected by fiberoptics bronchoscopy, and antibody was titrated by indirect (antiglobulin) bacterial agglutination. Responsiveness to vaccination was related in initial serum antibody concentrations. Calves with serum antibody titers of 1:20 or more were nonresponsive, whereas with few exceptions, calves having titers of less than 1:20 responded to vaccination. Results indicated that serum and lung antibody were induced by subcutaneous or by intrabronchial inoculation of formalinized P haemolytica. By either route of immunization, serum antibody was more persistent than was lung antibody, and pulmonary challenge exposure with live P haemolytica did not alter existing titers.

Animals↗
PubMedDate not supplied

[Quantitative determination of tissue disulfide groups by reverse amperometric titration].

A method of reversed amperometric titration for estimation of content of S- S-groups in biological materials is described. The method is based on splitting of disulphide groups in reaction with a reducing agent (Na2SO3) in presence of an excess of metal ions (Ag+, Hg2+), which form a mercaptide bond (AgS) with SH-groups. The excess of free metal ions was titrated with the equimolar solution of thiol (unithiol, cysteine). The method is comparatively simple and enables to estimate S- S groups in presence of air oxygen and enzymatic systems.

Blood Proteins↗
PubMed1983

Reverse plaque formation method for titration of non-cytopathogenic bovine viral diarrhea-mucosal disease virus.

The reverse plaque formation (RPF) method with a semi-micro plate was applied to the titration of a non-cytopathogenic (non-CP) strain of bovine viral diarrhea-mucosal disease (BVD-MD) virus. All the five non-CP strains used in this experiment formed reverse plaques (RP) on bovine testicle cell culture under methyl cellulose overlay. The RPF was inhibited by the pretreatment of a non-CP virus strain with immune rabbit serum to a reference strain. The specificity of the RPF method was demonstrated by the linear test and Poisson distribution test. Comparative titration of commercial BVD-MD vaccines was carried out by the semi-micro RPF method and the tube method based on the exaltation on Newcastle disease virus. The virus titer obtained by the former was slightly higher than that obtained by the latter. The former was proved to be a method of high sensitivity for determining non-CP virus.

Animals↗
PubMed1984

Titration of antibodies to Paracoccidioides brasiliensis by erythro-immunoassay (EIA).

The erythro-immunoassay, a new serological procedure in which a hybrid antibody conjugate is able to bind erythrocytes, was used for the titration of antibodies against P. brasiliensis in sera from patients with paracoccidioidomycosis. A peptide-polysaccharide and a lyophilized yeast culture filtrate of P. brasiliensis were used as antigens. Absorption with dead Candida albicans whole cells was necessary to decrease cross reactions observed with heterologous sera. Erythro-immunoassay provides a sensitive system for titration of antibodies in paracoccidioidomycosis with serum dilutions up to 1:102000.

Antibodies, Fungal↗
PubMed1980

Analysis of the acid-base titration curve of hen lysozyme.

The acid-base titration curves of hen egg-white lysozyme [EC 3.2.1.17] obtained by three groups (Sakakibara & Hamaguchi (1968) J. Biochem. 64, 613--619; Tanford & Roxby (1972) Biochemistry 11, 2192--2198; Pfeil & Privalov (1976) Biophys. Chem. 4, 23--32) were analyzed using the empirical formula of Linderstrøm-Lang. Hen lysozyme has 32 ionizable groups including the alpha-amino and alpha-carboxyl groups. Of the 21 groups other than the 11 arginyl residues, the pK values of 17 ionizable groups have been determined by various methods. Using these pK values, the pK values of the other four ionizable groups were estimated. The apparent pK values obtained were 2.0 (pKmit = 3.4), 2.1 (pKint = 3.5), 2.5 (pKint = 3.8), and 7.9 (pKint = 8.5) at 0.1 ionic strength and 25 degrees C. The titration curves obtained by the above three groups were consistently explained in terms of the same set of pKint values. The results obtained also showed that no buried and untitratable groups are present in the native lysozyme molecule.

Animals↗
PubMedDate not supplied

Blocking of immunofluorescence in the titration of membrane and intracellular reactive antibodies associated with herpesvirus of turkeys.

Blocking of the direct immunofluorescence (IF) reaction allowed titration of anti-membrane antigen (MA) or anti-intracellular antigen (IA) antibodies induced by herpesvirus of turkeys (HVT). The titers (blocking index) obtained by the blocking IF test were well correlated with those determined by the IF test. The results suggest that the blocking IF test was a simpler and better method for titration of a large number of serum samples from chickens infected with HVT.

Animals↗
PubMed1982

[(Studies on intragastric titration in man) ].

The method of intragastric titration uses food particles for stimulation of gastric acid secretion and is characterised by an excellent reproducibility. The food stimulated gastric acid secretion is influenced by the pH-value of the stimulus, whereas concentration of the peptone solution and volume of the test meal is less important. Postprandial gastrin release, however is altered by pH of the stimulus concentration and volume of the test meal. Intragastric titration represents an excellent method for measuring gastric acid secretion and should mainly be applied to clinical pathophysiological studies.

Female↗
PubMed1982

[Determination of the catalytic activity of lipase by the continuous titration method].

Development of a standardized procedure for the titrimetric assay of lipase has been suggested. Comparative studies with triolein und olive oil were therefore undertaken. Optimal conditions, such as pH, substrate and glycocholate concentrations, etc. were determined for the assay with triolein. The results agree with those obtained earlier with olive oil as substrate. Experience with the quality of various reagents used since 1966 is reported. Problems of methodology are then discussed, especially the incomplete characterization and purity of the bile acid preparations, and their effects on the test conditions. A critical analysis shows that two point tests with modifications of the continuous titration cannot give reliable results. Haemolysis and its effect on catalytic activity of lipase are used to illustrate the consequences of the uncritical acceptance of data from the literature. Furthermore, the required sensitivity of the analytical equipment, operational errors, and the uncritical evaluation and interpretation of analytical data are discussed. The first experiments to be performed with the addition of colipase are described, and the question of whether this cofactor should be used routinely for test purposes is considered. The problem of whether lipoproteinlipase can be quantitatively inhibited is discussed. In view of the outlay on apparatus and the time required for the assay, continuous titration is definitely not suitable for routine screening purposes. On the other hand, simpler methods that give reproducible quantitative results have not yet been developed.

Catalysis↗
PubMedDate not supplied

[Method for estimating data of potentiometric titration of membrane fragments by computers].

The flow chart of the computer programme is described for estimation of the quantity and pK values of separate ionogenic sites of the membrane based on the data of potentiometric titration with application of graphic method for calculation of parametres of titration differential curves. Its application makes it possible to reduce the time for calculating the potentiometric curves, to chose minima in the differential curve more objectively for characterization the pK values and to calculate areas of its different plots, which characterize binding capacity for ionogenic groups. The programme was written in the Analytic language for the MIR-2 computer.

Computers↗