In Vitro Release Behavior of Toremifene Citrate from Sol-Gel Processed Sintered Silica Xerogels

Factors affecting the adsorption and desorption of toremifene citrate (TC) on sintered silica xerogels were investigated in vitro. TC was attached onto sol-gel processed sintered silica xerogel grains or disks by adsorption. The adsorption of TC on the surface of silica was pH dependent. The results support the conclusion that large pore size results in highest drug adsorption. Adsorption of TC was most effective in xerogels sintered at 700°C and containing the largest pores and lowest specific surface area of the silica xerogels studied in the adsorption tests. The release of TC from the xerogel matrix was linear with respect to the square root of time. The release of TC from the grains was very rapid for the first 5 hr, followed by a slower release. All drug was released from the grains, and 60% to 80% was released from the disks in 24 hr. All drug-silica xerogel formulations showed sustained in vitro release profiles.     

Calcium phosphate induction by sol-gel-derived titania coatings on titanium substrates in vitro

OBJECTIVES: The objectives of this study were to document specific attributes of pulsatile luteinizing hormone secretion in middle-aged women before discernible alterations in their menstrual cycles and to compare the results to corresponding data obtained in younger women. STUDY DESIGN: After documenting normal cycle length, biphasic basal body temperatures, and normal midluteal progesterone in younger and middle-aged women during an initial cycle, daily blood samples and samples withdrawn at 10-minute intervals for 8 hours during the midfollicular phase were obtained during a subsequent cycle. RESULTS: Assessment of luteinizing hormone pulses with the pulse detection algorithm Cluster demonstrated a prolonged interpulse interval and increased pulse width in the older women. Assessment of luteinizing hormone secretory bursts and half-life with the deconvolution analysis procedure demonstrated a prolonged interburst interval and half-life in the older women. Appraisal of approximate entropy revealed greater orderliness of luteinizing hormone release in the older women. CONCLUSIONS: Middle-aged women exhibit alterations in hypothalamic-pituitary function that may account in part for age-related changes in reproductive potential.     

Pulmonary sarcoidosis: morphologic associations of airflow obstruction at thin-section CT

PURPOSE: To identify relationships between the obstructive defects of pulmonary sarcoidosis and the computed tomographic (CT) patterns of disease. MATERIAL AND METHODS: CT scans obtained in 45 patients were scored semiquantitatively for extent of five CT patterns, and the functional importance of each pattern was evaluated. RESULTS: The most prevalent CT patterns were decreased attenuation (n = 40), a reticular pattern (n = 37), and a nodular pattern (n = 36). At univariate and multivariate analyses, a reticular pattern was the main determinant of functional impairment, particularly airflow obstruction. The extent of a reticular pattern was independently associated with airflow obstruction, as shown by the inverse relationships with the forced expiratory volume in 1 second (FEV1) (P < .001), FEV1-forced vital capacity ratio (P < .01), maximum expiratory flow at 25% above residual volume (P < .001), and maximum expiratory flow at 50% above residual volume (P < .001) and the positive relationship with the residual volume-total lung capacity ratio (P < .001). CONCLUSION: In sarcoidosis, CT features compatible with small airways disease are common but contribute little to airflow obstruction, particularly in more advanced disease, which is characterized by an extensive reticular pattern. A reticular pattern at CT is the major morphologic association of airflow obstruction.     

The transverse location of the fluorescent probe trans-parinaric acid in lipid bilayers

The transverse location of trans-parinaric acid in spherical vesicles made up from dipalmitoylphosphatidylcholine has been investigated by the differential quenching of the probe fluorescence by 5- and 16-doxylstearic acid derivatives. The quenching data are interpreted in terms of a local fluorophore concentration factor. In this way it was found that the polyene of t-PnA is located within the inner part of the bilayer (presumably aligned with the bilayer lipids), both in the gel and in the liquid crystalline phases.     

Bee and wasp venom allergy in Turkey

Astrocytes and derived factors maintain the morphologic, phenotypic, and physiological properties of the blood-brain barrier. Astroglial cells may also modulate endothelial cell properties associated with the entry of inflammatory cells into the brain. The study of mechanisms of lymphocyte migration through the blood-brain barrier is critical to understanding the pathophysiology of autoimmune (multiple sclerosis) and virus-induced central nervous system diseases (HIV-induced dementia). In this context the contribution of astrocyte derived factors in regulating the interactions between inflammatory cells and endothelial cells of the blood-brain barrier was studied. The treatment of endothelial cells derived from brain or peripheral sources (hepatic) with astrocyte conditioned medium resulted in a dose dependent enhancement of adhesion of T cells to endothelium. The antigen specificity of the T cells did not influence the findings. Identical results were obtained with fresh Concanavalin A activated T cells and T cell hybridomas generated using myelin basic protein or chicken ovalbumin as immunogens. Further studies are in progress to define the active components in astrocyte conditioned medium and endothelial cell adhesion molecules that are regulated in order to gain a better understanding of mechanisms of inflammatory cell entry into the central nervous system.     

Comparison of aesthetic properties of tooth-colored restorative materials

A capillary electrophoresis system that integrated an enzymatic reaction and capillary polymer sieving electrophoresis was used to check the enzymatic stability of oligonucleotides. Phosphodiesterase I was employed to assess the susceptibility to 3'-exonucleolytic breakdown of some unmodified and modified oligonucleotides. Before degradation, the purity of the synthetic oligodeoxynucleotides was checked by capillary electrophoresis with a replaceable hydroxyethyl cellulose polymer solution. Enzymatic breakdown was achieved inside the capillary by merging substrate and enzyme zones based on their difference in electrophoretic mobility. After reaction, oligonucleotide fragments were swept to the detector, where they were individually detected and the remaining substrate was quantified. The results from the in-capillary degradation were compared to an off-line incubation and separation.     

An evaluation of a model ecosystem with DDT

The reproducibility, variability, and reliability of a simple aquatic-terrtestrial model ecosystem experiment was tested with p,p'-DDT. The variation among the model replicates as well as within the units was studied by using hierarchal analysis of variance. the complete budget of the chemical was calculated and a theoretical transport model was constructed. The degradation and accumulation of DDT was followed by gas chromatographic residue analysis, which showed good reproducibility of the experimental design. The degradation of DDT in the model was similar to that found in the field, but the determination of concentration factors was questionable. The material balance tables revealed that the soil and bottom substrates were the main contributors, which regulated the fate of the chemical in the model. The usefulness of the model is presented in this report.