Similar glycaemic control and risk of hypoglycaemia with patient- versus physician-managed titration of insulin glargine 300 U/mL across subgroups of patients with T2DM: a post hoc analysis of ITAS.

AIMS: The Italian Titration Approach Study (ITAS) demonstrated comparable HbA1c reductions and similarly low hypoglycaemia risk at 6 months in poorly controlled, insulin-naïve adults with T2DM who initiated self- or physician-titrated insulin glargine 300 U/mL (Gla-300) in the absence of sulphonylurea/glinide. The association of patient characteristics with glycaemic and hypoglycaemic outcomes was assessed. METHODS: This post hoc analysis investigated whether baseline patient characteristics and previous antihyperglycaemic drugs were associated with HbA1c change and hypoglycaemia risk in patient- versus physician-managed Gla-300 titration. RESULTS: HbA1c change, incidence of hypoglycaemia (any type) and nocturnal rates were comparable between patient- and physician-managed arms in all subgroups. Hypoglycaemia rates across subgroups (0.03 to 3.52 events per patient-year) were generally as low as observed in the full ITAS population. Small increases in rates of 00:00-pre-breakfast and anytime hypoglycaemia were observed in the ≤ 10-year diabetes duration subgroup in the patient- versus physician-managed arm (heterogeneity of effect; p < 0.05). CONCLUSIONS: Comparably fair glycaemic control and similarly low hypoglycaemia risk were achieved in almost all patient subgroups with patient- versus physician-led Gla-300 titration. These results reinforce efficacy and safety of Gla-300 self-titration across a range of phenotypes of insulin-naïve people with T2DM. CLINICAL TRIAL REGISTRATION: EudraCT 2015-001167-39.

Volumetría de fascículos cerebrales en población sana / Brain fascicles volumetry in healthy population

Objetivo Desde la aparición de la tractografía, al tratarse de una técnica no invasiva y que usa la ampliamente conocida resonancia magnética (RM), el estudio de la sustancia blanca se ha facilitado. A partir de eso, se han logrado grandes descubrimientos en cuanto a fascículos cerebrales involucrados en funciones cognitivas. Sin embargo, su evaluación sigue siendo subjetiva y depende de la experiencia y entrenamiento del evaluador, razón por la cual se ha limitado su aplicabilidad en la práctica clínica. En ese sentido, es conveniente parametrizar volúmenes cerebrales de sustancia blanca en población sana a través de una herramienta electrónica que se pueda reproducir y así poderlo aplicar en enfermos. Materiales y métodos Se reportan 10 sujetos sanos desde el punto de vista neurológico. Para cada sujeto, se adquirieron imágenes ponderadas por difusión y los resultados se visualizaron mediante FiberNavigator (http://scilus.github.io/fibernavigator). Finalmente, esa misma herramienta fue utilizada para purificar los fascículos objeto de estudio y realizar el conteo de las fibras. Resultados Se obtuvieron valores de volumetría del fascículo longitudinal superior (FLS), fascículo longitudinal inferior (FLI), fascículo frontoccipital inferior (FFI), fascículo uncinado (FU) y fascículo del cíngulo (FC), identificando que no existen diferencias estadísticamente significativas entre el número de fibras que componen los fascículos cerebrales. Discusión Los resultados alcanzados de la anatomía y la direccionalidad de fibras de los fascículos cerebrales de este estudio coinciden con el resto de la evidencia publicada hasta el momento, sin encontrar diferencias en cuanto a su organización y recorrido. Conclusión Aunque esos resultados no sirven como valores de referencia para ser aplicados en pacientes con patología neurológica, brindamos información inexistente hasta el momento, con ese equipo en específico y la reproducción entre los distintos usuarios y el software.

Objective Since the appearance of tractography, as it is a non-invasive technique and uses the widely known magnetic resonance (MR), the study of white matter has been facilitated. After this, great discoveries have been made regarding the brain fascicles involved in cognitive functions. However, its evaluation continues to be subjective and depends on the evaluator's experience and training. That the reason why its applicability has been limited in clinical practice. Because of this, it is convenient to parametrize cerebral volumes of white matter in healthy population through an electronic, reproducible tool that could be applied in patients. Materials and Methods Ten neurologically healthy subjects are reported, for each subject we acquired images weighted by diffusion and the results were visualized by means of FiberNavigator (http://scilus.github.io/fibernavigator). Finally, this same tool was used to purify the fascicles under study and perform the fiber count. Results Volumetric values of the upper longitudinal fasciculus, inferior longitudinal fasciculus, inferior frontoccipital fasciculus, uncinated fasciculus and cingulate fasciculus were obtained, identifying that there are not statistically significant differences in the number of fibers that make up the cerebral fascicles. Discussion The results achieved of the anatomical and fiber directionality of the cerebral fascicles of this study, coincide with the rest of the evidence published up to now, without finding differences regarding its organization and route. Conclusion Although these results do not serve as reference values to be applied in patients with neurological pathology, do we provide nonexistent information so far, with this specific equipment and the reproducibility between the different users and the software.

Capillary electrophoretic apparatus for the endpoint detection in microtitration methods.

Titration methods are routinely used in the laboratories for the quantification of acids and bases, for the complexometric determination of metal ions and for the ion-pair titrations of drugs in pharmaceutical control. They also find application in a wide variety of chemical and biochemical studies. However, conventional titration methods (CTM) require large amounts of samples that are not always available. In absence of micro-titrator devices, the application of these methods for expensive samples and for small batch sizes is not possible. In this work, it was demonstrated that the commercial capillary electrophoretic apparatus (CEa) can be used, in a quick and easy way, for the end-point detection in a microtitration process. The proposed methodology exploits the change of the solutions conductivity during the titrations. The equivalent points can be easily located by plotting the change in electrical current as a function of the titrant volume added. More interestingly, only 1.1-1.5 mL of analyte solutions are required to establish the titration curves. The advantages and the limitations of the procedure are discussed in detail.

Filling Blank Spots on the Map: Identification of Ligand Binding Modes and Interacting Water Molecules for Brd4-BD1 by WaterLOGSY Titrations.

Fragment-based drug discovery and continuous improvement of existing protein inhibitors rely on the knowledge of exactly how and how strongly a range of small molecules bind to their respective protein targets. By increasing the (perdeuterated) protein concentration, WaterLOGSY titration experiments give access to ligand binding modes even in the case of weak binders as well as to the location of protein-bound water in the surroundings of the ligand. On the basis of these findings, specific chemical modifications of the ligand could be shown to yield significantly enhanced binding affinities.

Maintaining Interrater Agreement of Core Assessment Instruments in a Multisite Randomized Controlled Clinical Trial: The Randomized Evaluation of Sedation Titration for Respiratory Failure (RESTORE) Trial.

BACKGROUND: RESTORE (Randomized Evaluation of Sedation Titration for Respiratory Failure) was a cluster randomized clinical trial evaluating a sedation strategy in children 2 weeks to <18 years of age with acute respiratory failure supported on mechanical ventilation. A total of 31 U.S. pediatric intensive care units (PICUs) participated in the trial. Staff nurse rater agreement on measures used to assess a critical component of treatment fidelity was essential throughout the 4-year data collection period. OBJECTIVE: The purpose of the study is to describe the method of establishing and maintaining interrater agreement (IRA) of two core clinical assessment instruments over the course of the clinical trial. METHODS: IRA cycles were carried out at all control and intervention sites and included a minimum of five measurements of the State Behavioral Scale (SBS) and Withdrawal Assessment Tool-Version 1 (WAT-1). Glasgow Coma Scale scores were also obtained. PICUs demonstrating <80% agreement repeated their IRA cycle. Fleiss's kappa coefficient was used to assess IRA. RESULTS: Repeated IRA cycles were required for 8% of 226 SBS cycles and 2% of 222 WAT-1 cycles. Fleiss's kappa coefficients from more than 1,350 paired assessments were .86 for SBS and .92 for WAT-1, demonstrating strong agreement and similar to .91 for the Glasgow Coma Scale. There was no difference in Fleiss's kappa for any of the instruments based on unit size or timing of assessment (earlier or later in the study). For SBS scores, Fleiss's kappa was significantly different in larger and smaller PICUs (.82 vs. .92, p = .003); however, Fleiss's kappa for both groups indicated excellent agreement. CONCLUSION: Monitoring measurement reliability is an essential step in ensuring treatment fidelity and, thus, the validity of study results. Standardization on the use of these core assessment instruments among participating sites was achieved and maintained throughout the trial.

Comparison between titrimetric and spectrophotometric methods for quantification of vitamin C.

Vitamin C is usually quantified by titrimetric or chromatographic methods. However, these methods have limitations: food color interferes with the titrimetric method and the chromatographic method is costly. The aim of this study was to compare a spectrophotometric method, based on reduction of cupric ions in the presence of cuproine complex, with a titrimetric method, based on reduction of 2,6-dicholorophenolindophenol. Linearity, precision, accuracy, and limits of detection (LOD) and quantification (LOQ) were evaluated using a standard vitamin C solution. Both methods were also applied for AA quantification in industrialized orange and pineapple juices. The methods were precise and accurate when applied to the standard solution. The spectrophotometric method was more sensitive, with lower values for LOD (0.002mgmL-1) and LOQ (0.010mgmL-1), and more accurate with error less than 5% while results from the titrimetric method were affected by the juice color, which generated errors in excess of 15%.

[Adaptation of methotrexate determination in serum with Unicel DxC600(®)]. / Adaptation du dosage sérique du méthotrexate sur Unicel DxC600(®).

High-dose methotrexate treatment requires pharmacological monitoring in order to tailor administration of folinic acid to reduce side effects. The aim of the study was to validate the adaptation of the EMIT reagent on the l'Unicel DxC 600® Beckman Coulter. The establishment of two assays was necessary to obtain a quantification limit as low as possible (0.05 µmol/L). The linearity of the adapted methods extends from 0.05 to 0.25 µmol/L on the one hand, and from 0.25 to 1 µmol/L on the other hand. For each method, fidelity and accuracy were studied and the limits of detection and quantification were quantified. The correlation with the FPIA method was performed on the Abbott TDX(®). The results of all tests are satisfactory with coefficients of variation (CV) of repeatability and reproducibility of less than 6%. However the daily assays are heavy as 66% of blood samples require at least two dosages and 30% a manual dilution.

Investigation of amine-buffered amide reagents for coulometric Karl Fischer titration.

Formamide (FA), N-methylformamide (NMF), and dimethylformamide (DMF), were evaluated as solvents for coulometric Karl Fischer (KF) reagents in combination with several amine bases. Except for the effect of the iodine species (iodine or triiodide), the pH of the reagent and the position of the sulfur dioxide/hydrogen sulfite equilibrium were found to be the main factors explaining the large difference in the observed reaction rates between water and the KF reagent in these solvents. Acid-base titrations showed that hydrogen sulfite is the main sulfur reactant in these media. The results will be of great importance in finding suitable combinations of base and solvent with respect to stoichiometry, side reactions caused by active carbonyl compounds, and reagent stability.

Uncertainty due to volumetric operations is often underestimated.

Fifteen international titration standards were evaluated to determine minimum and maximum combined standard uncertainties. Assuming most thorough performance of the analyses revealed minimum values, whereas maximum values of uncertainty were obtained assuming that the analyses had been done under high time pressure. Minimum and maximum uncertainties were compared with the corresponding reproducibility standard deviations. Since the combined standard uncertainty is expected to lie between the reproducibility standard deviation and the maximum combined standard uncertainty, realistic standard uncertainties of individual influence quantities of volumetric and weighing procedures could be calculated. This top-down approach revealed up to 4 times higher uncertainties for volumetric operations compared to the bottom-up approach according to the current literature. Hence, uncertainty due to volumetric operations is obviously strongly underestimated. The present study additionally contains a ranking of the contributions to the uncertainty of titrimetric results.

Comparison of flame atomic absorption spectrometry (FAAS) and Cerimetric methods for the determination of ferrous sulfate content of some pharmaceutical products.

The iron content of ferrous sulphate syrup and tablet, ferroglobin, and Fefol were determined by both titration with cerium (Cerimetric method) proposed by united state pharmacopeias and flame atomic absorption spectrometry (FAAS). In FAAS both external calibration and standard addition method were used to evaluate the matrix effects. In the determination of iron content of ferrous sulphate tablet and syrup FAAS using external standard give approximately the same results as cerimetric methods of analysis. But in the case of ferroglobin syrup and Fefol capsule the external calibration results had large deviation from cerimetric method of analysis. So flame atomic absorption spectrometric involving standard addition is proposed for the analysis of iron content of these pharmaceutical products. The coefficient of variation for the FAAS determinations were in the range of 0.73-5.85 in one day and 2.39-7.51 between different days. Statistical evaluation showed good correlation between two methods.

Reducing the variation in performance of antibody titrations.

BACKGROUND: Antibody titration is difficult to standardize. We investigated whether a detailed, uniform procedure for antibody titration would reduce variation in both tube-based and gel card titres in an international study. METHODS: Laboratories (n = 35) tested proficiency testing material provided by the College of American Pathologists each according to (i) their routine method; (ii) a detailed, uniform method; and (iii) the uniform method titrating the serum sample against a red cell of specified phenotype (D+ C- c+ E+ e- for anti-D; A(1) for anti-A) instead of the red cell of the same phenotype provided in the proficiency testing kit. Uniform method results were reported with 1+ and w+ end-points. Paired statistical analyses of variance were conducted using the F-test. RESULTS: The variance between laboratories was not significantly reduced with the uniform method using a 1+ end-point. However, a statistically significant reduction in the variance of anti-D and anti-A titres by the tube-based uniform technique after 37 degrees C incubation and conversion to the antiglobulin (AHG) phase was seen when 19 laboratories reanalyzed their results using a w+ end-point. Too few laboratories reported results with a w+ end-point in gel card testing to allow analysis. Titration against red cells of the specified phenotype provided by the participating laboratory did not appear to introduce additional variance. Overall, results reported based on the gel card technique at the AHG phase (1+ end-point) showed reduced variance compared to tube-based techniques. CONCLUSIONS: A detailed, uniform method for antibody titration at 37 degrees C and read at the AHG phase in a tube-based method with a w+ end-point reduced interlaboratory variability.

Analysis of the purity of cetrimide by titrations.

The purity of cetrimide, trimethyl tetradecyl ammonium bromide (TTAB), which is an important preservative of many cosmetic and pharmaceutical products, was determined by three independent methods of titration. Traditionally, cetrimide was analysed by an assay method of the European Pharmacopoeia, which showed consistently a low purity of cetrimide with associated large standard deviations, however. A systematic 3% bias of the European Pharmacopoeia assay method was identified by comparing the result with results of two alternative methods of titration that exhibited high precision and high accuracy. Titration by perchloric acid showed a 99.69% +/- 0.05% purity of cetrimide, and titration by silver nitrate showed a 99.85% +/- 0.05% purity, while the traditional assay method predicted a purity of only 97.1% +/- 0.4%. It was found that the discrepancy could be identified as differences in selectivity during the extraction step of the European Pharmacopoeia assay method. The distribution coefficients between chloroform and water of cetrimide and the corresponding iodide species (TTAI) were thus determined as 2150 +/- 50 M(-1) and 68000 +/- 4000 M(-1), respectively.

Improving method capability of a drug substance HPLC assay.

The assay of a drug substance (DS) is one of the tests required to confirm the active pharmaceutical ingredient (API) quality at release. In the past, usually volumetric titration methods were performed, that were precise, but often non-specific. Nowadays specific chromatographic assay procedures are preferred. However, high performance liquid chromatographic (HPLC) methods, the way they are usually executed, tend to be less precise and have a larger total method variation compared to titration methods. The capabilities of fully validated titration and HPLC assay methods were determined and compared. It was studied which factors had the largest effects on the capability of chromatographic HPLC methods in order to improve their precision and precision-to-tolerance ratio. This was done using multiple Gage R&R (repeatability & reproducibility) studies and an experimental design approach. The investigations showed that it was feasible to define an HPLC method with a similar capability as the titration method. The most important factor determining the precision was demonstrated to be higher sample and reference material weights. When low weights are to be used, increasing the number of sample preparations and the number of reference solutions may enhance the method capability.

Transdermal opioids for cancer pain.

Patients with moderate to severe malignancy-related pain frequently require the use of opioid pharmacotherapy. Unfortunately, many cancer patients continue to be prescribed subtherapeutic doses of pain medications resulting in undo suffering and diminished quality of life. The choice of analgesic pharmacotherapy should be individualized and based on the intensity and etiology of pain reported by the patient. Health care providers must be able to readily quantify the relative analgesic potency when converting from one opioid to another or from one route of administration to another. Transdermal fentanyl is effective and well tolerated pharmacotherapy for the cancer pain patients. However, clinicians need to be cognizant that the U.S./U.K. manufacturer's recommendations for equilalagesic dosing of transdermal fentanyl may result in initial doses that produce subtherapeutic levels and unrelieved pain in some patients. A more aggressive dosing algorithm for transdermal fentanyl using a 2:1 (mg/day of oral morphine: mcg/hr of transdermal fentanyl) conversion ratio that considers both a review of the literature and clinical experience should help clinicians individualize cancer pain pharmacotherapy. Transdermal buprenorphine is now being prescribed in Europe and Australia for chronic and cancer pain management. Buprenorphine's mixed agonist/antagonist activity, dosage ceiling, and high affinity to the opiate receptor limits its use to those patients who do not already require large daily doses of opioids. Thus, buprenorphine may not be an appropriate medication for some patients with advanced unremitting cancer pain.

Impact of a standardized titration protocol with carvedilol in heart failure: safety, tolerability, and efficacy-a report from the GESICA registry.

Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina (GESICA) studied whether a standardized protocol for the initiation and titration of the beta-blocker carvedilol in a multicenter, open-label program would optimize beta-blocker use in heart failure (HF) patients. The program included: (1) the carvedilol initiation and titration period, and (2) long-term follow-up at 6 and 12 months. Of 1299 patients in the registry, 504 were excluded due to current therapy; of the remaining 795 eligible patients, 293 were excluded due to contraindications. Of the included patients with follow-up data (n = 316), 93.3% tolerated carvedilol initiation and 47.7% of the patients reached the target dose of 50 mg/day for a mean dose of 39 mg/day. Rates were comparable in the elderly (n = 83), of which 53% achieved a target dose for a mean dose of 43.08 mg/day. This protocol improved therapy rates and achieved target doses quickly (average of 4 visits). Concomitant medications did not have to be adjusted and there were low withdrawal rates (10%) and hospital admissions (7.2%) for HF. Patients were able to maintain carvedilol therapy at 6 and 12 months. These results indicate that a standardized titration protocol, as used in GESICA, for the initiation and titration of beta-blockers is well tolerated and may improve beta-blocker use in carefully selected heart failure patients.

[Rapid immunotitration of individual toxins from Androctonus australis venom]. / Immunodosage rapide des toxines individuelles du venin d'Androctonus australis.

Passive immunotherapy against scorpion envenomations is facilitated by the preliminary titration of circulating toxins in envenomed patients. Currently, routinely used ELISA tests allow only the titration of the whole venom, without reference to the toxins which compose the venom and spread variably within the tissue. Taking as a model one of the three toxins responsible for the lethal effects of Androctonus australis hector (Aahl) venom, we developed an ELISA sandwich test based on a fragment of recombining antibody (scFv) consisting of the variable chains of the monoclonal IgG 9C2 coupled to a decapeptide showing high affinity for streptavidine. Conjugate scFvlStrep-tag was prepared by genetic engineering. It was produced in the periplasm of recombining bacteria, in a reproducible way, in a soluble form, at low cost and with an output, after purification, of 0.8 mg/L of bacterial culture. The recombinant protein, of small size (28 kDa), is bifunctional. It preserves a very high affinity for the toxin Aah I (Kd of 2.3 10(-10) M, very close to that of IgG 9C2), yet recognises streptavidine and its conjugate (streptavidine-peroxidase). The titration of the Aahl toxin used an ELISA sandwich test in which the toxin was captured in a specific way by a monoclonal antibody; the immunocomplexes were then detected by recombinant immunoconjugate, thus conferring a high specificity on titration. The test is quick (90 mn), reproducible and sensitive, with a limit of detection of 0.6 toxin (ng.ml-1). This method could be extended to two other lethal toxins of the venom of the scorpion Androctonus australis hector and to those of other species. New perspectives are thus possible for the diagnosis of the envenomations.

Measurement of meal-stimulated gastric acid secretion by in vivo gastric autotitration.

Measurement of meal- stimulated gastric acid secretion using manual intragastric titration is demanding in terms of personnel and specialized equipment. In the present study, we used a new method, in vivo gastric autotitration, to determine meal-stimulated gastric acid secretion. Gastric pH was measured every 4 s before, during, and after ingestion of a standard meal in 24 healthy subjects. Placebo, ranitidine (150 mg), ranitidine (75 mg), or famotidine (10 mg) was given 1 h after the beginning of the meal. Meal-stimulated gastric acid secretion was calculated from the amount of HCl required to titrate the homogenized standard meal to pH 2 in vitro (119 mmol) and the time required for the pH of the ingested meal to decrease to pH 2 in vivo. Values for pH were also converted to acid concentration (mM), and integrated acidity was calculated from the cumulative, time-weighted means of the acid concentrations for every fourth second of the postprandial recording period. Control meal-stimulated gastric acid secretion was 60 (40-71) mmol/h (median; interquartile range), and each histamine H(2)-receptor antagonist significantly decreased secretion by approximately 50%. Meal-stimulated acid secretion correlated directly with postprandial integrated gastric acidity (r = 0.72; P = 0.0001). Thus intragastric autotitration is a convenient, reproducible method for measuring gastric acid secretion after ingestion of a solid meal and offers several advantages over manual intragastric titration.

Measurement of paralytic shellfish toxins in molluscan extracts: comparison of the microtitre plate saxiphilin and sodium channel radioreceptor assays with mouse bioassay, HPLC analysis and a commercially available cell culture assay.

This study compared five methods of measuring paralytic shellfish toxins (PSTs) including the long-used mouse lethality bioassay, a commercially available cell culture test (MIST Quantification kit), HPLC analysis, and two newly developed radioreceptor assays utilizing mammalian sodium channels and saxiphilin. Methods were challenged with toxic shellfish extracts prepared according to the AOAC official method. The best correlations between predicted toxicity values being 0.9 or better, were those between HPLC analysis when compared with both radioreceptor assays and the mouse lethality bioassay, as well as that between the saxiphilin and the sodium channel radioreceptor assays. In all cases, statistically significant correlations existed between the toxicity measurements of the same extracts. The ratios between some methods were not unitary as measured by the slopes of the regression lines used for correlation analyses. HPLC analysis predicted more toxicity than all of the bioassays. The saxiphilin assay underestimated toxicity relative to the mouse bioassay, the MIST kit determinations and the sodium channel assay. The sodium channel assay predicted there to be less toxicity than the mouse bioassay and the MIST kit. Of all of the techniques used, the MIST kit correlation with the mouse bioassay was nearest to one. Each method possesses differentt virtues and it may be that a multi-method approach would harness the benefits of each method for various aspects of a shellfish testing regime.