Predictors of immune-related adverse events and outcomes in patients with NSCLC treated with immune-checkpoint inhibitors

OBJECTIVE

To identify predictors of immune-related adverse events (IRAEs) in patients with non-small cell lung cancer (NSCLC) treated with immune checkpoint inhibitors (ICIs). Assess associations between outcomes and the development of IRAEs.

METHODS

Retrospective analysis of patients with NSCLC treated with ICIs between 2016 and 2020 in the Pulmonology Department of our hospital. Patients with and without IRAEs were compared. A logistic regression analysis was performed to determine predictors of IRAEs. Progression-free survival (PFS) and overall survival (OS) curves were calculated using the Kaplan-Meier method, and the long-rank test was used to assess survival differences between groups. Univariate and multivariate Cox proportional-hazards regression models were used to identify factors associated with PFS and OS. The value considered statistically significant was p≤0.05.

RESULTS

A total of 184 patients (77.7% men, mean age 66.9±9.5 years) treated with ICIs were analyzed. During follow-up, 49 (26.6%) patients developed IRAEs and 149 (81.0%) died. According to the multivariate logistic regression analysis, treatment with statins (OR:3.15; p = 0.007), previous systemic corticosteroid therapy (OR:3.99; p = 0.001), disease controlled as response to ICI (OR:5.93; p < 0.001) and higher hemoglobin values (OR:1.28; p = 0.040) were independent predictors for the development of IRAEs. Patients who developed IRAEs had significantly longer medians of PFS (41.0 vs 9.0 weeks, p < 0.001) and OS (89.0 vs 28.0 weeks; p < 0.001).

CONCLUSIONS

Patients treated with statins, pre-ICI systemic corticosteroids, higher baseline hemoglobin value and controlled disease as initial response to ICI had a higher risk of developing IRAEs. The development of IRAEs was associated with better outcomes.

Parenting Styles, Internalization of Values and Self-Esteem: A Cross-Cultural Study in Spain, Portugal and Brazil

The present study analyzes the impact of parenting styles on adolescents' self-esteem and internalization of social values in three countries, Spain, Portugal and Brazil. The sample of the study was comprised of 2091 adolescents from Spain (n = 793), Portugal (n = 675), and Brazil (n = 623) from 12-18 years old (52.1% females). The four types of parenting styles, authoritative, indulgent, authoritarian and neglectful, were measured through the warmth and strictness dimensions of the Scale of Parental Socialization ESPA29. The two criteria variables were captured with the five dimensions of the AF5, Five-Factor Self-Concept Questionnaire, and with self-transcendence and conservation Schwartz values. Results confirm emergent research in parenting socialization: the use of parental warmth is evidenced as key for adolescent self-esteem and internalization of social values in the three countries analyzed. Indulgent and authoritative parenting (both characterized by parental warmth) are associated with the highest value internalization in the three countries. Furthermore, indulgent parenting (use of warmth) is associated with the highest adolescent self-esteem, overcoming authoritative parenting (use of warmth and strictness). The influence of parenting over adolescent self-esteem and values internalization is maintained independent of the differences in self-esteem and value priorities observed in the cultural context, the sex and age of the participants.

Comparison of ELISA and HPLC-MS methods for the determination of exenatide in biological and biotechnology-based formulation matrices

The development of biotechnology-based active pharmaceutical ingredients, such as GLP-1 analogs, brought changes in type 2 diabetes treatment options. For better therapeutic efficiency, these active pharmaceutical ingredients require appropriate administration, without the development of adverse effects or toxicity. Therefore, it is required to develop several quantification methods for GLP-1 analogs products, in order to achieve the therapeutic goals, among which ELISA and HPLC arise. These methods are developed, optimized and validated in order to determine GLP-1 analogs, not only in final formulation of the active pharmaceutical ingredient, but also during preclinical and clinical trials assessment. This review highlights the role of ELISA and HPLC methods that have been used during the assessment for GLP-1 analogs, especially for exenatide.

Researching Parental Socialization Styles across Three Cultural Contexts: Scale ESPA29 Bi-Dimensional Validity in Spain, Portugal, and Brazil

Recent research that relates parenting with adolescent adjustment has shown the importance of considering the cultural context of the relationship. New results are emerging when considering the classical four-typologies model of parental socialization in some European and South-American countries. Among the instruments used in this emergent research is the Parental Socialization Scale ESPA29. This scale is a bi-dimensional parenting instrument that was specifically developed to measure the four parenting typologies, through the dimensions of acceptance/involvement and strictness/imposition. This study examines the good fit of the orthogonal bi-factor model based on the ESPA29 versus one-dimensional and bi-dimensional oblique alternative models, with three adolescent samples from 12 to 17 years old (53.4% girls), from Spain (N = 826), Portugal (N = 752), and Brazil (N = 628). We applied structural equation models (SEMs) to analyze the fit of the models to the data. The results confirm a better fit to the data for the orthogonal bi-factor model versus one-dimensional and bi-dimensional oblique alternative models across country, adolescent sex, and the three age groups. Additionally, the convergent validity of the scale was proved by showing the relation of the two parenting dimensions with self-concept. The results guarantee the adequacy of the ESPA29 to measure parenting styles.

Intervenção Psicoeducativa na Prevenção do Stress na Infância: a Formação de Educadores

A profissionalidade docente, no quadro dos processos de ensino-aprendizagem, constitui um desafio ao nível da formação especializada, especialmente numa perspetiva life span. Este estudo tem como objetivo geral identificar o tipo de intervenção psicoeducativa que permite atuar ao nível da prevenção do stress. Os resultados mostraram existir correlações moderadas entre as situações indutoras de stress de Causas Internas Psicossociais e as Causas Externas de Componente Familiar. Também as práticas educativas atentas à Cooperação Escola-Família estão correlacionadas com as Atividades de Prevenção das situações indutoras de stress na infância. São recomendados programas de intervenção psicoeducativa na formação de Educadores.

Envolvimento dos estudantes no ensino superior: um estudo com a escala EAE-E4D

Enquadramento Conceptual: Considera-se o Envolvimento do Aluno na Escola um constructo quadri-dimensional, abrangendo as dimensões; cognitiva, afetiva, comportamental e agenciativa. Objetivo: Analisar as qualidades psicométricas da adaptação para contexto de ensino superior, da escala de Envolvimento dos Alunos na Escola: uma Escala Quadri-Dimensional - EAE-E4D. Metodologia: Quantitativa. Amostra de 715 estudantes do Ensino Superior. Resultados: Estudo das propriedades psicométricas da escala EAE-E4D através da análise factorial e da avaliação da consistência interna. Os resultados reproduzem valores semelhantes aos da escala original. Conclusões: O questionário EAE-E4D apresenta boas qualidades psicométricas e pode, também, ser usado com estudantes do Ensino Superior.

Envolvimento dos alunos na escola e suas perceções acerca do apoio parental

Esta investigação de natureza quantitativa e correlacional tem como objectivo conhecer a relação do apoio parental com o envolvimento escolar dos filhos e identificar quais os comportamentos específicos dos pais que se relacionam significativamente com o envolvimento dos filhos na escola. A amostra foi constituída por 330 alunos do 10 º ano de escolaridade, de uma Escola Secundária da área de Lisboa. Os resultados indicam uma relação positiva entre a percepção dos alunos do apoio parental e o envolvimento dos alunos na escola. Foram identificados comportamentos parentais que se relacionam com o envolvimento escolar dos alunos .

Low Molecular Weight Heparin (Enoxaparin) Versus Oral Anticoagulant Therapy (Acenocoumarol) in the Long-Term Treatment of Deep Venous Thrombosis in the Elderly: a Randomized Trial

This study aims to establish the relative effectiveness and safety of low molecular weight heparin in elderly patients with venous thrombosis in order to find an alternative to oral anticoagulant therapy with less bleeding complications in the long-term treatment of deep venous thrombosis (DVT).

One hundred consecutive elderly patients (>75 years old) with venographically demonstrated proximal DVT were included in a randomized trial. All patients were treated for ten days with adjusted doses of intravenous heparin. Informed consent was obtained and on the eight day, patients were randomly allocated to receive acenocoumarol (INR 2.0-3.0) or subcutaneous enoxaparin (4000 anti-Xa units once a day) for three months. All patients were followed-up clinically and venographically for a one year period. The results were analyzed with Fisher’s exact test or chi-square test as appropriate.

During the treatment and surveillance period, 6 of the 50 patients (12%) who received acenocoumarol and 8 of the 50 patients (16%) who received enoxaparin had new episodes of venous thromboembolism confirmed by objective testing (p = 0.6; 95% CI for the difference: −19.5 to 11.5). Hemorrhagic complications occurred in six of the 50 patients (12%) who received acenocoumarol and in one (2%) of those on enoxaparin (p = 0.1; 95% CI for the difference: -1.8 to 21.8). Vertebral fractures developed in 2 patients (4%) in the enoxaparin group (p = 0.5; 95% CI for the diference: −11.4 to 3.4).

These results show that fixed dose enoxaparin seems to be effective and safe in the long-term treatment of proximal DVT in the elderly. In comparison with oral anticoagulants, the findings are inconclusive due to the wide confidence intervals for differences between outcomes, however they suggest that the former may have less bleeding complications with similar efficacy.

Unusual presentations of Comamonas kerstersii infection

The association of Comamonas kerstersii with peritonitis resulting from the presence of perforated appendix has previously been described by our research team. In the present study, we describe the isolation of this microorganism from two forms of unusual presentations of C. kerstersii infection not previously described in the literature: localized intra-abdominal infection (psoas abscess) and pelvic peritonitis.

Advance in methods studying the pharmacokinetics of polyphenols

Significant advances have been achieved during the past decade concerning the metabolism of polyphenol compounds in vitro, but scarce data has been presented about what really happens in vivo. Many studies on polyphenols to date have focused on the bioactivity of one specific molecule in aglycone form, often at supraphysiological doses, whereas foods contain complex, often poorly characterized mixtures with multiple additive or interfering activities. Whereas most studies up to the middle-late 1990s measured total aglycones in plasma and urine, after chemical or enzymatic deconjugation, or both, several recent works now report the polyphenol conjugate composition of plasma, urine, feces and/or tissues, after the administration of pure polyphenols or polyphenol-rich matrices. HPLC methods with electrochemical, mass spectrometric and fluorescence detection have adequate sensitivity. LC/UV-Vis methods have also been widely reported, but they are much less sensitive. Compared with electro-chemical and fluorescence detection, MS can quantify analytes without chromatographic separation, which leads to high throughput, presenting itself as the best choice to date. Regarding the experimental model to monitor the bioavailability of phenolic compounds, most published studies are based on human and animal models, with the majority using rodents, primates and recently the nematode Caenorhabditis elegans. This review focuses on the fundamentals of pharmacokinetic methods from the last 15 years and how the results are evaluated and validated. The types of analytical methods, animal models and biological matrices were used to better elucidate pharmacokinetics of polyphenols.

The Differentiation and Promotion of Students’ Rights in Portugal

This investigation includes a differential study (Study 1) and a quasi-experimental research (Study 2). In Study 1, the objective was to establish to what extent students’ rights existed and analyse the differentiation between students’ rights with Portuguese and immigrant mothers, throughout school years. The sample consisted of 537 students with Portuguese and immigrant mothers, distributed by different school years (7th, 9th and 11th grades). The Children’s Rights Scale (Hart et al., 1996; Veiga, 2001) was used. In Study 2, the purpose was to analyse the effects on students’ rights of the use by teachers of a communicational intervention program, supervised by school psychologists. The sample involved 7th and 9th grade students, in a total of four classes, two forming the experimental groups ( n = 36) and two the control groups ( n = 43); as in Study 1, the Children’s Rights Scale was used. The results indicated the effectiveness of the communicational intervention program on students’ rights and are consistent with previous studies. An implication is that psychologists and teachers, working together and taking a human rights perspective, may develop an important role in projects to promote the students’ rights.

Oral Controlled Release Dosage Forms. II. Glassy Polymers in Hydrophilic Matrices

Part I of this article reported general considerations of oral controlled release dosage forms and the applications of cellulose ether polymers in hydrophilic matrices. Part II of this study describes the advantages and disadvantages of limited swelling hydrophilic matrices, their preparation, mechanism, and parameters affecting drug release from these systems.

Compatibility Studies Between Ibuprofen or Ketoprofen with Cellulose Ether Polymer Mixtures Using Thermal Analysis

Differential scanning calorimetry (DSC) was used to investigate and detect incompatibilities between drugs such as: ibuprofen (IBU) or ketoprofen (KETO) with cellulose ether derivatives, which are frequently applied on controlled release dosage forms. Binary mixtures concerning methylcellulose (MC25) or hydroxypropylcellulose (HPC) with hydroxypropylmethylcellulose (HPMC) K15M or K100M in different ratios were prepared and evaluated by the appearance, shift, or disappearance of peaks and/or variations in the corresponding DeltaH values. According to the DSC results, binary mixtures between those polymers were found to be compatible, but their mixture with IBU or KETO, promotes a solid-solid interaction mainly with 1:1:1 (w/w) ratio (drug-excipient). However, when the drug:excipient interactions were detected, they were not found to affect the drug bioavailability. DSC was successfully employed to evaluate the compatibility of the drugs with the selected polymers.

Role of Cellulose Ether Polymers on Ibuprofen Release from Matrix Tablets

Cellulose derivatives are the most frequently used polymers in formulations of pharmaceutical products for controlled drug delivery. The main aim of the present work was to evaluate the effect of different cellulose substitutions on the release rate of ibuprofen (IBP) from hydrophilic matrix tablets. Thus, the release mechanism of IBP with methylcellulose (MC25), hydroxypropylcellulose (HPC), and hydroxypropylmethylcellulose (HPMC K15M or K100M) was studied. In addition, the influence of the diluents lactose monohydrate (LAC) and beta-cyclodextrin (beta-CD) was evaluated. Distinct test formulations were prepared containing: 57.14% of IBP, 20.00% of polymer, 20.29% of diluent, 1.71% of talc lubricants, and 0.86% of magnesium stearate as lubricants. Although non-negligible drug-excipient interactions were detected from DSC studies, these were found not to constitute an incompatibility effect. Tablets were examined for their drug content, weight uniformity, hardness, thickness, tensile strength, friability, porosity, swelling, and dissolution performance. Polymers MC25 and HPC were found to be unsuitable for the preparation of this kind of solid dosage form, while HPMC K15M and K100M showed to be advantageous. Dissolution parameters such as the area under the dissolution curve (AUC), the dissolution efficiency (DE(20 h)), dissolution time (t 50%), and mean dissolution time (MDT) were calculated for all the formulations, and the highest MDT values were obtained with HPMC indicating that a higher value of MDT signifies a higher drug retarding ability of the polymer and vice-versa. The analysis of the drug release data was performed in the light of distinct kinetic mathematical models-Kosmeyer-Peppas, Higuchi, zero-, and first-order. The release process was also found to be slightly influenced by the kind of diluent used.

Insulin-loaded nanoparticles are prepared by alginate ionotropic pre-gelation followed by chitosan polyelectrolyte complexation

Alginate nanoparticles were prepared from dilute alginate sol by inducing a pre-gel with calcium counter ions, followed by polyelectrolyte complex coating with chitosan. Particles in the nanometer size range were obtained with 0.05% alginate and 0.9 mM Ca2+. The mean particle size was influenced by time and stirring speed of nanoparticle preparation, by alginate guluronic acid content and chitosan molecular weight and by the initial alginate:chitosan mass ratio. The association efficiency of insulin into alginate nanoparticles, as well as loading capacity were mainly influenced by the alginate:chitosan mass ratio. Under optimized size conditions, the association efficiency and loading capacities were as high as 92% and 14.3%, respectively. Approximately 50% of the protein was partially retained by the nanoparticles in gastric pH environment up to 24 hours while a more extensive release close to 75% was observed under intestinal pH conditions. Mild formulation conditions, optimum particle size range obtained, high insulin entrapment efficiency, and resistance to gastrointestinal release seem to be synergic and promising factors toward development of an oral insulin delivery form.

Alginate/chitosan nanoparticles are effective for oral insulin delivery

PURPOSE

To evaluate the pharmacological activity of insulin-loaded alginate/chitosan nanoparticles following oral dosage in diabetic rats.

METHODS

Nanoparticles were prepared by ionotropic pre-gelation of an alginate core followed by chitosan polyelectrolyte complexation. In vivo activity was evaluated by measuring the decrease in blood glucose concentrations in streptozotocin induced, diabetic rats after oral administration and flourescein (FITC)-labelled insulin tracked by confocal microscopy.

RESULTS

Nanoparticles were negatively charged and had a mean size of 750 nm, suitable for uptake within the gastrointestinal tract due to their nanosize range and mucoadhesive properties. The insulin association efficiency was over 70% and insulin was released in a pH-dependent manner under simulated gastrointestinal conditions. Orally delivered nanoparticles lowered basal serum glucose levels by more than 40% with 50 and 100 IU/kg doses sustaining hypoglycemia for over 18 h. Pharmacological availability was 6.8 and 3.4% for the 50 and 100 IU/kg doses respectively, a significant increase over 1.6%, determined for oral insulin alone in solution and over other related studies at the same dose levels. Confocal microscopic examinations of FITC-labelled insulin nanoparticles showed clear adhesion to rat intestinal epithelium, and internalization of insulin within the intestinal mucosa.

CONCLUSION

The results indicate that the encapsulation of insulin into mucoadhesive nanoparticles was a key factor in the improvement of its oral absorption and oral bioactivity.

Influence of cellulose ether mixtures on ibuprofen release: MC25, HPC and HPMC K100M

The influence of cellulose ether derivatives on ibuprofen release from matrix tablets was investigated. Raman spectroscopy and differential scanning calorimetry (DSC) experiments were used, in order to examine the compatibility between the matrix components: both excipients and ibuprofen. While both the DSC and Raman results did not detect any incompatibilities, DSC revealed the existence of some drug:excipient interactions, reflected by variations in the hydration/dehydration processes. Formulations containing mixtures of polymers with both low and high viscosity grades-methylcellulose (MC25) or hydroxypropylcellulose (HPC), and hydroxypropylmethylcellulose (HPMC K100M), respectively--were prepared by a direct compression method (using 20, 25, and 30% of either MC25 or HPC). The tablets were evaluated for their drug content, weight uniformity, hardness, thickness, tensile strength, friability, porosity, surface area, and volume. Parameters such as the mean dissolution time (MDT) and the dissolution efficiency (DE) were calculated in all cases. The solid formulations presently studied demonstrated a predominantly Fickian diffusion release mechanism.

[Self-concept in adults from Spain and Portugal]

The aim of this work is to confirm the penta-factorial validity of the AF5 Self-Concept Questionnaire in Spanish and Portuguese adults. From the responses of a total of 2058 adults (1508 Spanish, 73.3%, and 550 Portuguese, 26.7%) was analyzed the reliability of the instrument, was compared the validity of the 5 oblique factor model proposed by the authors versus unifactorial and the orthogonal alternative models, and was studied the invariance of the Portuguese translation. The results of structural equation modeling supported the authors' penta-factorial model. The multi-group factorial invariance showed that Portuguese translation of the AF5 does not change neither the original factor weights, nor the variances and covariances of the factors. Finally, the reliability was good for the original Spanish version and Portuguese translation.

Conformational study of ketoprofen by combined DFT calculations and Raman spectroscopy

A conformational study of ketoprofen was carried out by both density functional theory (DFT) calculations and Raman spectroscopy. Nine different geometries were found to correspond to energy minimum conformations but only one of them was experimentally detected in the condensed phase spectra. Those rotations which interconvert the five most stable conformers were studied and the intramolecular interactions governing the corresponding conformational preferences were assessed. A thorough vibrational analysis was performed, leading to the assignment of both the solid and liquid spectra. Evidence for formation of intermolecular hydrogen bonds between carboxylic groups of adjacent ketoprofen molecules, leading to dimeric entities, was obtained.

Influence of cellulose ether polymers on ketoprofen release from hydrophilic matrix tablets

The present work reports the study of different ketoprofen:excipient formulations, in order to determine the effect of the polymer substitution and type of diluent on the drug-release mechanism. Substituted cellulose-methylcellulose, hydroxypropylcellulose and hydroxypropylmethylcellulose were used as polymers, while lactose monohydrate and beta-cyclodextrin were tested as diluents. Distinct test formulations were prepared, containing 57.14% of ketoprofen, 20.00% of polymer, 20.29% of diluent, and 1.71% of talc/0.86% of magnesium stearate as lubricants. The tablets were tested for their drug content, weight variation, hardness, thickness, tensile strength, friability, swelling and release ratio. Polymers MC25 and HPC were found not to be appropriate for the preparation of modified release ketoprofen hydrophilic matrix tablets, while HPMC K15M and K100M showed to be advantageous. The analysis of the release profiles in the light of distinct kinetic models (zero-order, first-order, Higuchi and Korsmeyer-Peppas) led to the conclusion that the type of polymer did not influence the release mechanism of the drug. The mean dissolution time (MDT) was determined, the highest MDT value being obtained for HPMC formulations. Moreover, the drug-release process was found to be slightly influenced by the type of diluent, either lactose or beta-cyclodextrin.

[Multicenter, prospective study comparing enoxaparin with unfractionated heparin in the treatment of submassive pulmonary thromboembolism]

OBJECTIVE

To compare the safety and efficacy of enoxaparin and unfractionated heparin in the treatment of submassive pulmonary thromboembolism (PTE).

MATERIAL AND METHODS

Fifty-six patients with PTE who did not need fibrinolytic treatment were enrolled prospectively. The patients were randomly assigned to 2 treatment groups: Group A received enoxaparin (1 mg/kg every 12 hours) and Group B received adjusted doses of unfractionated heparin. The oral anticoagulant therapy was started on confirmation of the diagnosis and continued for 6 months. Incidences of recurrence of thromboembolism and of severe bleeding were assessed at the end of this period.

RESULTS

Six patients were withdrawn from the study. Twenty-nine of the 50 remaining patients were in Group A (enoxaparin) and 21 in Group B (unfractionated heparin). A recurrence of thromboembolism was diagnosed in 3 patients from Group A (10.7%) and 2 patients from Group B (9.5%). There were no significant differences. Two patients died, one death being attributed to bleeding secondary to the oral anticoagulant treatment (Group A) and the other to a process unrelated to PTE.

CONCLUSIONS

Enoxaparin seems to be as effective and safe as unfractionated heparin in the initial treatment of PTE.

Effect of polymer hydration on the kinetic release of drugs: a study of ibuprofen and ketoprofen in HPMC matrices

Samples of drug/hydroxypropylmethylcellulose (HPMC) mixtures and matrices (drug/HPMC mixtures plus excipients) were allowed to equilibrate in closed chambers with defined relative humidities (RHs). Their water uptake and drug release were evaluated by differential scanning calorimetry/thermogravimetric analysis and dissolution studies, respectively. Analysis of the thermal behaviors of the drug/HPMC mixtures and of the polymer alone, as functions of RH, leads to the conclusion that most of the hydration water is retained by the polymer, and points to the occurrence of different types of hydration water, from the strongly polymer-bound water molecules at RH values up to 81%, to the almost "free water" for RH values close to 100%. In addition, application of the Korsmeyer model to the dissolution results leads to the conclusion that the rate determining dissolution processes are predominantly of the fickian type.

Physical properties of chitosan pellets produced by extrusion–spheronisation: influence of formulation variables

Pellets comprising chitosan, cellulose microcrystalline, povidone, filler excipient and diclofenac sodium as model drug were prepared by extrusion-spheronisation. The effects of chitosan load (zero, 0%, low, 4% and high, 16% levels), type of filler (lactose, tribasic calcium phosphate and beta-cyclodextrin) and composition of the binding liquid (ethanol/water mixtures 20 and 50%) on physical characteristics of pellets were evaluated. A three-factor factorial design was employed in the study. Analysis of variance (ANOVA) indicated that single factors had significant effect on the physical characteristics of the pellets. The type of filler followed by polymer load markedly affected the density. The type of binding liquid had negligible effect on the shape and surface roughness of the pellets. Increase in the chitosan load resulted in pellets of lower porosity values. This could be attributed to the binding capacity of chitosan and povidone leading to more compacted structures. Chitosan load and type of filler had significant influence on the surface roughness. The surface of pellets became rougher as the chitosan load increased, however, there was no significant difference between zero and low contents of chitosan. Pellets prepared using tribasic calcium phosphate showed a smoother surface when compared with formulations including lactose or beta-cyclodextrin. Chitosan was useful to provide pellets of acceptable physical characteristics when employing an alcohol/water mixture 50% (v/v) as binding liquid for the extrusion-spheronisation process.

Influence of the preparation method on the physicochemical properties of tolbutamide/cyclodextrin binary systems

Tolbutamide (TBM) was found to form an inclusion complex with beta cyclodextrin (beta-CD) in solution and in solid state. Inclusion complex formation between tolbutamide and beta-cyclodextrin in aqueous solution was studied by phase solubility and spectral shift methods. The apparent stability constant Ks calculated by these techniques, in water, were estimated as 195.7 and 236.5 M(-1), respectively. The phase solubility studies revealed a B(S)-type diagram with an inclusion complex of 1:2 molar ratio. The solid inclusion complexes of TBM and beta-CD were prepared at a molar ratio of 1:2 by kneading, coprecipitation, freeze-drying, and spray-drying methods. In addition, the physical mixture was prepared. Characterization of TBM: beta-CD inclusion was performed using differential scanning calorimetry (DSC), Raman spectroscopy, and X-ray diffractometry and by application of a so-called ether wash method. All the inclusion systems investigated led to a significant improvement in the dissolution over free TBM, and the dissolution rate of the active material was observed to be independent of the preparation method.

Dynamics of glyphosate and aminomethylphosphonic acid in a forest soil in Galicia, north-west Spain

Residues of the herbicide glyphosate (N-phosphonomethylglicine) and its main metabolite, aminomethylphosphonic acid (AMPA), were determined in a forest soil in north-west Spain, previously treated with 5 and 8 l ha(-1) of glyphosate. Both products were monitored in the solid and liquid soil phases for an 8-week period after the treatment. Soil samples were extracted by KH2PO4. Concentrated extracts and liquid phase samples were derivatized with 9-fluorenylmethyl chloroformate (FMOC) before determination by HPLC using an anion exchange column and spectrofluorometric detection. The treated soil peaked at 6.9 microg g(-1) of glyphosate, whereas soil water samples peaked at 0.74 microg ml(-1) of glyphosate. One month after the treatment, both glyphosate and AMPA concentrations in soil and water samples were almost negligible. AMPA peaked at 0.77 microg ml(-1) in soil water samples. Glyphosate and AMPA exhibited high vertical mobility in the treated soil, quickly reaching high concentrations in subsurface horizons where the degradation is slower.

The influence of diluent on the release of theophylline from hydrophilic matrix tablets

The role of beta-cyclodextrin (beta-CD) on the apparent solubility of theophylline was investigated by the solubility method. Binary systems of theophylline and beta-CD were prepared using the dry co-grinding method. Their characterization was performed by differential scanning calorimetry (DSC). The dissolution rate of theophylline and theophylline/beta-CD and dissolution studies of matrix tablets prepared from mixtures containing theophylline and ground theophylline were carried out. It can be concluded that beta-CD is related to an increase in the apparent solubility and dissolution rate of the drug, promoting improvement on the release of theophylline from matrices manufactured with hydroxypropylmethylcellulose (HPMC). This can be attributed to the amorphous state and the increased wettability of the drug.

Low molecular weight heparin (enoxaparin) versus oral anticoagulant therapy (acenocoumarol) in the long-term treatment of deep venous thrombosis in the elderly: a randomized trial

This study aims to establish the relative effectiveness and safety of low molecular weight heparin in elderly patients with venous thrombosis in order to find an alternative to oral anticoagulant therapy with less bleeding complications in the long-term treatment of deep venous thrombosis (DVT). One hundred consecutive elderly patients (>75 years old) with venographically demonstrated proximal DVT were included in a randomized trial. All patients were treated for ten days with adjusted doses of intravenous heparin. Informed consent was obtained and on the eight day, patients were randomly allocated to receive acenocoumarol (INR 2.0-3.0) or subcutaneous enoxaparin (4000 anti-Xa units once a day) for three months. All patients were followed-up clinically and venographically for a one year period. The results were analyzed with Fisher's exact test or chi-square test as appropriate. During the treatment and surveillance period, 6 of the 50 patients (12%) who received acenocoumarol and 8 of the 50 patients (16%) who received enoxaparin had new episodes of venous thromboembolism confirmed by objective testing (p = 0.6; 95% CI for the difference: -19.5 to 11.5). Hemorrhagic complications occurred in six of the 50 patients (12%) who received acenocoumarol and in one (2%) of those on enoxaparin (p = 0.1; 95% CI for the difference: -1.8 to 21.8). Vertebral fractures developed in 2 patients (4%) in the enoxaparin group (p = 0.5; 95% CI for the difference: -11.4 to 3.4). These results show that fixed dose enoxaparin seems to be effective and safe in the long-term treatment of proximal DVT in the elderly. In comparison with oral anticoagulants, the findings are inconclusive due to the wide confidence intervals for differences between outcomes, however they suggest that the former may have less bleeding complications with similar efficacy.

Oral bioavailability and hypoglycaemic activity of tolbutamide/cyclodextrin inclusion complexes

The purpose of the present study was to evaluate the enhancement of tolbutamide (TBM) oral bioavailability and hypoglycaemic activity through complexation with beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD). TBM and its freeze-dried inclusion complexes were administered to rabbits (New zealand breed; n=6), in a dose of 20 mg/kg. TMB plasma levels were measured by HPLC and glucose levels were analysed according to Trinder (Trinder, P., 1969. Determination of glucose in blood using glucose oxidase with an alternative oxygen acceptor. Ann. Clin. Biochem. 6, 24-28). The pure drug attained a maximum of plasma concentration (C(max)) of 18.58+/-3.27 microg/ml at 8.5 h (T(max)), whereas with inclusion complexes, C(max) increased about two times and appeared at ca. 4 h. AUC(0-24) of complexes was about 1.6 times as much as that of the pure drug. Thus, the extent of oral absorption of TBM from inclusion complexes was significantly greater and faster when compared with drug alone. In addition, without cyclodextrins the maximum hypoglycaemic effect (CVG(max)) of TBM (34. 1%) was observed at 5.6 h (Tg(max)). CVG(max) of TBM/beta-CD and TBM/HP-beta-CD inclusion complexes were 34.1% (at 6.5 h) and 37.7% (at 5.1 h), respectively. AAC(0-24) of inclusion complexes was 1.4 times larger than that of pure drug. Hence, the oral administration of complexed TBM not only improved the drug absorption, but also the TBM hypoglycaemic activity.

Dynamic three-dimensional echocardiography: a new era in ultrasound technology

The use of noninvasive methods to visualise the heart has had an extraordinary development over the last decade, with echocardiography demonstrating a particularly fast growth. Despite its unquestionable role in the diagnosis of heart disease and in the management of cardiac patients, it does have some limitations, both in the morphological visualisation, as well as in the functional assessment of the heart, such as blood flow, quantification of intracardiac volumes, etc. The recent development of dynamic three-dimensional (3D) echocardiography from two dimensional images has opened new perspectives in the study of cardiac pathophysiology. There are basically two methods of displaying three dimensional data sets: (1) a two-dimensional display from individual selected cut planes (any-plane echocardiography) or from parallel short axis cuts; (2) a volume rendered technique: from any defined cut plane, different algorithms are applied to represent the information in space. There are several potential clinical applications of 3D such as the measurement and serial follow-up of left ventricular volumes; in valvular heart disease (the abnormalities can be delineated more precisely and in greater detail than conventional imaging, including a detailed definition of mitral apparatus in mitral stenosis), in mitral valve prolapse both leaflets can be seen from the left atrial view and in endocarditis it can aid in deciding when and how to intervene; in complex congenital heart disease, such as reconstruction of double outlet right ventricle, left-sided obstructive and regurgitant lesions and subaortic obstructive cases, in atrial and ventricular septal defects, displaying size, geometry and relationships to other structures; another expression of cardiac disorders are blood flow disturbances (visualisation of flows in 3D could allow a better qualitative and quantitative assessment of their size and severity; the pictures so far generated allow a good perception of the size and shape of mitral, aortic and tricuspid regurgitation jets, by examining them from a new perspective, it also has the potential to display the flow convergence zone and quantify the regurgitant volume). Recent studies have clearly demonstrated the feasibility of performing three-dimensional imaging in a variety of cardiac diseases, but continued development of ultrasound technology must be made to improve better image resolution. The prolonged acquisition time is the most important limiting factor that currently restricts the routine use of 3D echocardiography. The development of faster computers will shorten the time needed for image acquisition, postprocessing, and data analysis, contributing to the goal of easy access and wide use. With improvements in computer technology and production of interactive software, 3D echocardiography will provide a dynamic view of the surgical anatomy of the heart. Thus, the three-dimensional reconstruction concept has the potential to and diagnostic assessment of cardiac pathology in every facet.

Functional, histologic, and ultrastructural study of the protective effects of verapamil in experimental ischemic acute renal failure in the rabbit

The present study was performed in vivo in rabbits to evaluate the functional and morphologic effects of verapamil in a model of ischemic acute renal failure (ARF). Particularly impressive was the ultrastructural integrity of renal tubules in the animals exposed to both ischemia and verapamil. Three groups were studied: Group A: no ischemia; Group B: renal ischemia alone; and Group C: renal ischemia with verapamil. Creatinine clearance was higher in Group C (0.77 mL/min/kg) compared to Group B (0.13 mL/min/kg) at 24 h of reperfusion (p < .005) as well as at 48 and 72 h (0.73 mL/min/kg) vs. 0.35 mL/min/kg; p < .05 and 0.90 mL/min/kg vs. 0.46 mL/min/kg; p < 0.05, respectively). Light microscopic evaluation of Group C rabbits revealed significantly better preservation of proximal tubule (PT) brush border (p < .0005) and less desquamation of PT (p < .05) compared to Group B. Ultrastructural examination of in vivo perfused kidneys also demonstrated decreased loss of microvilli of PT (p < .0005) as well as less cellular edema (p < .005), fewer cells with apical PT membrane rupture (p < .01), better preservation of mitochondria (p < .005), less flattening of the PT basolateral labyrinth (p < .05), and fewer hypertrophic actin bands at the basal surface of PT epithelial cells (p < .05). These results suggest that verapamil markedly attenuates PT morphologic injury in a rabbit model of reversible ischemic ARF. The functional protection observed in these studies may be related, in part, to the improved structural integrity of the renal tubules. Renal transplantation and anticipated renal ischemia (i.e., surgical interventions) are two important situations where treatment with verapamil or other calcium channel blockers may prove to be clinically beneficial.