Search

Deviant physiological reactivity to infant stimuli has been suggested to underlie maladaptive parenting behavior. Our study involved 44 maltreating and 42 non-maltreating mothers. During a standardized cry paradigm, mothers listened to nine cry sounds of varying pitches. Saliva was collected at baseline, after each cry sound, and after a recovery episode. Salivary α-amylase (sAA) as a marker of autonomic nervous system (ANS) activity was assayed from saliva samples. Maltreating mothers showed lower overall sAA levels and an attenuated reactivity pattern to infant crying as compared to non-maltreating mothers. No effect of type of maltreatment (neglect only vs. neglect and abuse) was found. Furthermore, positive correlations between sAA and heart rate (HR) for non-maltreating mothers differed significantly from non-significant correlations between sAA and HR for maltreating mothers. This suggests anomalous asynchrony between different aspects of the ANS in maltreating mothers. Results indicate a lack of functional autonomic (re)activity as a contributing risk factor to child maltreatment.

Handgrip force responses to infant signals were examined in a sample of 43 maltreating and 40 non-maltreating mothers. During a standardized handgrip paradigm, mothers were asked to squeeze a handgrip dynamometer at maximal and at half of their maximal handgrip strength while listening to infant crying and laughter sounds. Maltreating mothers used excessive force more often while listening to infant crying and laughter than non-maltreating mothers. Of the maltreating mothers, only neglectful mothers (n=20) tended to use excessive force more often during crying than non-maltreating mothers. Participants did not rate the sounds differently, indicating that maltreating mothers cannot be differentiated from non-maltreating mothers based on their perception of infant signals, but show different behavioral responses to the signals. Results imply that, in response to infant signals (i.e., crying or laughing), maltreating mothers may be insufficiently able to regulate the exertion of physical force., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The purpose of this study is to characterize the inter-grade and inter-batch variability of sodium alginate used in the formulation of matrix tablets. Four different grades and three batches of one grade of sodium alginate were used to prepare matrix tablets. Swelling, erosion, and drug release tests of sodium alginate matrix tablets were conducted in a USP dissolution apparatus. Substantial differences in swelling and erosion behavior of sodium alginate matrix tablets were evident among different viscosity grades. Even different batches of the same grade exhibit substantial differences in the swelling and erosion behavior of their matrix tablets. The erosion behavior of sodium alginate matrix tablets can be partly explained by their rheological properties (both apparent viscosity and viscoelasticity) in solution. Sodium alginate with higher apparent viscosity and viscoelasticity in solution show slower erosion rate and higher swelling rate. Compacts prepared from grades or batches with higher viscosity and higher viscoelasticity show slower drug release. For grades or batches with similar apparent viscosities, apparent viscosities of sodium alginate solution at low concentration alone are not sufficient to predict the functionality of sodium alginate in matrix tablets. Viscoelastic properties of sodium alginate solutions at one high concentration corresponding to the polymer gel state, may be suitable indicia of the extended release behavior of sodium alginate matrix tablets.

Long acting β₂-agonists (LABA) have been reported to modify the extracellular matrix (ECM) composition in the airway wall. Based on our earlier studies we here investigated the mechanism underlying the control of ECM modification by LABA in primary human airway smooth muscle cells. Cells were treated with formoterol or salmeterol (30 min) before TGF-β₁ stimulation (2-3 days) Using RT-PCT, immuno-blotting and ELISA the de novo synthesis and deposition of collagen type-I, -III, -IV and fibronectin were determined. Matrix metalloproteinases (MMP)-2 and -9 were analyzed by zymography. Both LABA activated cAMP and its corresponding transcription factor CREB within 60 min and thus partly reduced TGF-β₁-induced gene transcription of collagen type-I, -III, fibronectin and connective tissue growth factor (CTGF). The inhibitory effect of both LABA on collagen type-I and -III deposition involved a cAMP dependent mechanism, while the inhibitory effect of the two drugs on TGF-β1-induced fibronectin deposition and on CTGF secretion was independent of cAMP. Interestingly, none of the two LABA reduced CTGF-induced synthesis of collagen type-I or type-III deposition. In addition, none of the two LABA modified collagen type-IV deposition or the expression and activity of MMP-2 or MMP-9. Our results show that LABA can prevent de novo deposition of specific ECM components through cAMP dependent and independent signaling. However, they do not reduce all ECM components by the same mechanism and they do not reduce existing collagen deposits. This might explain some of the controversial reports on the anti-remodeling effect of LABA in chronic inflammatory lung diseases., (Copyright © 2014 Elsevier Inc. All rights reserved.)

We examined autonomic reactivity to infant crying in a sample of 42 maltreating and 38 non-maltreating mothers. Exploratively, we tested if differential reactivity was related to child neglect versus the combination of neglect and abuse, and we tested whether mothers' experiences with maltreatment in their own childhood moderated the association between their current maltreatment status and physiology. During a standardized cry paradigm, mothers listened to cry sounds of various pitches. Heart rate (HR), pre-ejection period (PEP), skin conductance levels (SCLs), and vagal tone (root mean square of successive differences [RMSSD]) were measured as indicators of underlying sympathetic and parasympathetic reactivity. The maltreating mothers showed lower SCL reactivity to the cry sounds than non-maltreating mothers. Furthermore, significant negative correlations between HR and PEP in the non-maltreating group differed from nonsignificant correlations in the maltreating group, which suggests a lack of sympathetic cardiac control in maltreating mothers. We found no differences between neglectful mothers and those who were additionally abusive. Together, our findings support the notion of sympathetic hypoarousal as a risk factor for child maltreatment, which may be indicative of disengagement in a caregiving context. Intervention programs might focus on improving maternal sensitivity to improve responsiveness to child signals., (© The Author(s) 2014.)

Background: Pulmonary arterial hypertension is characterized by increased thickness of pulmonary vessel walls due to both increased proliferation of pulmonary arterial smooth muscle cell (PASMC) and deposition of extracellular matrix. In patients suffering from pulmonary arterial hypertension, endothelin-1 (ET-1) synthesis is up-regulated and may increase PASMC activity and vessel wall remodeling through transforming growth factor beta-1 (TGF-β1) and connective tissue growth factor., Objective: To assess the signaling pathway leading to ET-1 induced proliferation and extracellular matrix deposition by human PASMC., Methods: PASMC were serum starved for 24 hours before stimulation with either ET-1 and/or TGF-β1. ET-1 was inhibited by Bosentan, ERK1/2 mitogen activated protein kinase (MAPK) was inhibited by U0126 and p38 MAPK was inhibited by SB203580., Results: ET-1 increased PASMC proliferation when combined with serum. This effect involved the mitogen activated protein kinases (MAPK) ERK1/2 MAPK and was abrogated by Bosentan which caused a G1- arrest through activation of p27((Kip)). Regarding the contribution of extracellular matrix deposition in vessel wall remodeling, TGF-β1 increased the deposition of collagen type-I and fibronectin, which was further increased when ET-1 was added mainly through ERK1/2 MAPK. In contrast, collagen type-IV was not affected by ET-1. Bosentan dose-dependently reduced the stimulatory effect of ET-1 on collagen type-I and fibronectin, but had no effect on TGF-β1., Conclusion and Clinical Relevance: ET-1 alone does not induce PASMC proliferation and extracellular matrix deposition. However, ET-1 significantly up-regulates serum induced proliferation and TGF-β1 induced extracellular matrix deposition, specifically of collagen type-I and fibronectin. The synergistic effects of ET-1 on serum and TGF-β1 involve ERK1/2 MAPK and may thus present a novel mode of action in the pathogenesis of pulmonary arterial hypertension.

Solid-state nuclear magnetic resonance (SSNMR) spectroscopy has become more prevalent in the pharmaceutical industry due to its nondestructive nature and the wealth of information it can provide on a wide variety of solid samples. In this study, SSNMR spectra and relaxation times were used to analyze differences in monomer composition, molecular weight (MW), and water content among various sodium alginate samples. Differences in structure could be determined via spectral deconvolution of SSNMR spectra, and differences in intrinsic viscosity, MW, and water content were found to correlate to SSNMR relaxation times. The technique was found to be selective and sensitive enough to detect these changes in sodium alginate even when diluted with another excipient and compressed into a tablet., (Copyright © 2011 Wiley-Liss, Inc.)

The purpose of this study is to determine whether sodium alginate solutions' rheological parameters are meaningful relative to sodium alginate's use in the formulation of calcium alginate gels. Calcium alginate gels were prepared from six different grades of sodium alginate (FMC Biopolymer), one of which was available in ten batches. Cylindrical gel samples were prepared from each of the gels and subjected to compression to fracture on an Instron Universal Testing Machine, equipped with a 1-kN load cell, at a cross-head speed of 120 mm/min. Among the grades with similar % G, (grades 1, 3, and 4), there is a significant correlation between deformation work (L(E)) and apparent viscosity (η(app)). However, the results for the partial correlation analysis for all six grades of sodium alginate show that L(E) is significantly correlated with % G, but not with the rheological properties of the sodium alginate solutions. Studies of the ten batches of one grade of sodium alginate show that η(app) of their solutions did not correlate with L(E) while tan δ was significantly, but minimally, correlated to L(E). These results suggest that other factors--polydispersity and the randomness of guluronic acid sequencing--are likely to influence the mechanical properties of the resultant gels. In summary, the rheological properties of solutions for different grades of sodium alginate are not indicative of the resultant gel properties. Inter-batch differences in the rheological behavior for one specific grade of sodium alginate were insufficient to predict the corresponding calcium alginate gel's mechanical properties.

Polymeric excipients are often the least well-characterized components of pharmaceutical formulations. The aim of this study was to facilitate the QbD approach to pharmaceutical manufacturing by evaluating the inter-grade and inter-batch variability of pharmaceutical-grade polymeric excipients. Sodium alginate, a widely used polymeric excipient, was selected for evaluation using appropriate rheological methods and test conditions. The materials used were six different grades of sodium alginate and an additional ten batches of one of the grades. To compare the six grades, steady shear measurements were conducted on solutions at 1%, 2%, and 3% w/w, consistent with their use as thickening agents. Small-amplitude oscillation (SAO) measurements were conducted on sodium alginate solutions at higher concentrations (4-12% w/w) corresponding to their use in controlled-release matrices. In order to compare the ten batches of one grade, steady shear and SAO measurements were performed on their solutions at 2% w/w and 8% w/w, respectively. Results show that the potential interchangeability of these different grades used as thickening agents could be established by comparing the apparent viscosities of their solutions as a function of both alginate concentration and shear conditions. For sodium alginate used in controlled-release formulations, both steady shear behavior of solutions at low concentrations and viscoelastic properties at higher concentrations should be considered. Furthermore, among batches of the same grade, significant differences in rheological properties were observed, especially at higher solution concentrations. In conclusion, inter-grade and inter-batch variability of sodium alginate can be determined using steady shear and small-amplitude oscillation methods.

A pharmaceutical formulation typically contains one or more excipients in addition to the active pharmaceutical ingredient(s). Though excipients have been considered inert components of a formulation, variability in their properties has been shown to affect the performance of drug dosage forms and delivery systems. This study investigates the inter- and intra-manufacturer variability among different NF grades and lots of xanthan gum made by two manufacturers. As many formulators rely on compendial standards to monitor and control the variability of excipients, this study focuses on the adequacy of the NF specifications, in particular the viscosity specification, to discern the variability in solution properties of different pharmaceutical grades and lots of xanthan gum. All the grades and lots in this study were NF grade materials. Xanthan gum solutions were prepared in accordance with NF test methodology and were rheologically evaluated using a rotational rheometer. Both steady shear measurements and small amplitude oscillatory measurements were carried out on 1% w/w xanthan gum solutions. Results showed significant inter- and intra-manufacturer variability among the NF grades and lots of xanthan gum that was not reflected in the NF viscosity test specifications.

Asthma is a chronic inflammatory condition characterised by a variable degree of airflow limitation. Exacerbations during the course of asthma often occur due to environmental factors or infectious, mostly viral, aetiology. The present study reports the case of a 61-yr-old male with severe asthma hospitalised due to increasing respiratory distress. Since recovery was delayed despite anti-obstructive/anti-inflammatory and antibiotic therapy, further diagnostic procedures, including bronchoscopy, were performed in order to attempt to identify the cause of the worsening respiratory condition. The surprising finding consisted of a rare coincidence of concomitant infection with the bacterial pathogen Alcaligenes xylosoxidans, grown from bronchoalveolar lavage fluid, and the protozoan parasite Leishmania spp., revealed by histopathological examination of bronchial mucosal biopsy specimens. This is the first report of an isolated bronchial mucosal involvement of Leishmania in an HIV-negative asthma patient following brief exposure in Leishmania-endemic regions. Further, to the best of the present authors' knowledge, this represents the first description of A. xylosoxidans in asthma, although it is questionable whether it was an infection or colonisation. The present observation identifies previously unreported microbial pathogens associated with asthma exacerbation. Further, the report highlights the importance of obtaining a thorough travel history and applying invasive diagnostic procedures in circumstances of treatment failure, even under unfavourable conditions.

Proliferation of vascular smooth muscle cells (VSMC) contributes to the progression of atherosclerotic plaques. Calcium channel blockers have been shown to reduce VSMC proliferation, but the underlying molecular mechanism remains unclear. p21(Waf1/Cip1) is a potent inhibitor of cell cycle progression. Here, we demonstrate that amlodipine (10(-6) to 10(-8) M) activates de novo synthesis of p21(Waf1/Cip1) in vitro. We show that amlodipine-dependent activation of p21(Waf1/Cip1) involves the action of the glucocorticoid receptor (GR) and C/EBP-alpha. The underlying pathway apparently involves the action of mitogen-activated protein kinase or protein kinase C, but not of extracellular signal-related kinase or changes of intracellular calcium. Amlodipine-induced p21(Waf1/Cip1) promoter activity and expression were abrogated by C/EBP-alpha antisense oligonucleotide or by the GR antagonist RU486. Amlodipine-dependent inhibition of cell proliferation was partially reversed by RU486 at 10(-8) M (58%+/-29%), antisense oligonucleotides targeting C/EBP-alpha (91%+/-26%), or antisense mRNAs targeting p21(Waf1/Cip1) (96%+/-32%, n=6); scrambled antisense oligonucleotides or those directed against C/EBP-beta were ineffective. The data suggest that the anti-proliferative action of amlodipine is achieved by induction of the p21 (Waf1/Cip1) gene, which may explain beneficial covert effects of this widely used cardiovascular therapeutic drug beyond a more limited role as a vascular relaxant.

Primary pulmonary hypertension is a fatal disease causing progressive right heart failure within 3 years after diagnosis. We describe a new concept for treatment of the disease using vasoactive intestinal peptide, a neuropeptide primarily functioning as a neurotransmitter that acts as a potent systemic and pulmonary vasodilator. Our rationale is based on the finding of a deficiency of the peptide in serum and lung tissue of patients with primary pulmonary hypertension, as evidenced by radioimmunoassay and immunohistochemistry. The relevance of this finding is underlined by an upregulation of corresponding receptor sites as shown by Northern blot analysis, Western blot analysis, and immunological techniques. Consequently, the substitution with the hormone results in substantial improvement of hemodynamic and prognostic parameters of the disease without side effects. It decreased the mean pulmonary artery pressure in our eight study patients, increased cardiac output, and mixed venous oxygen saturation. Our data provide enough proof for further investigation of vasoactive intestinal peptide and its role in primary pulmonary hypertension.

Background: Pulmonary hypertension is a frequent complication of severe chronic obstructive pulmonary disease (COPD) and a major cause of morbidity and mortality in this condition. Based on the improved survival of these patients due to long term oxygen therapy and the potent and selective pulmonary vasodilation by inhaled nitric oxide, the safety and effectiveness of the combined inhalation of these two gases over a 3 month period was assessed., Methods: Forty patients with secondary pulmonary hypertension due to COPD were randomly assigned to receive either oxygen alone or "pulsed" inhalation of nitric oxide with oxygen over a period of 3 months. "Pulsed" inhalation of nitric oxide was used to reduce pulmonary ventilation-perfusion mismatch and formation of toxic reaction products of nitric oxide and oxygen., Results: Compared with oxygen alone, the combined inhalation of nitric oxide and oxygen caused a significant decrease in mean (SE) pulmonary artery pressure (from 27.6 (4.4) mm Hg to 20.6 (4.9) mm Hg, p<0.001) and pulmonary vascular resistance index (from 569.7 (208.1) to 351.3 (159.9) dyne x s(-1) x cm(-5) x m(-2), p<0.001) without decreasing arterial oxygenation. Cardiac output increased by 0.5 litres (from 5.6 (1.3) l/min to 6.1 (1.0) l/min, p=0.025). Systemic haemodynamics and left heart function remained unchanged during this period and no increase in toxic reaction products of nitric oxide was observed., Conclusions: This is the first controlled trial indicating that the "pulsed" inhalation of nitric oxide together with oxygen may be safely and effectively used for the long term treatment of severe COPD.

Objectives: To evaluate the effect of long-term oral therapy with sildenafil in patients with pulmonary arterial hypertension receiving long-term IV epoprostenol., Design: Open, uncontrolled trial., Setting: University hospital., Patients: Two patients with primary pulmonary hypertension and one patient with pulmonary arterial hypertension after surgical closure of an atrial septal defect. All patients were receiving continuous epoprostenol for 1.7 to 7.1 years; two patients also received inhaled iloprost for 1.8 years and 3.8 years, respectively., Interventions: Addition of oral sildenafil, up to 200 mg/d, divided in four to six single doses, and hemodynamic measurements and the 6-min walking distance (6MWD) before and after 5 months of treatment with sildenafil., Results: One patient was treated with sildenafil, 200 mg/d; two patients received 75 mg/d due to nausea and headache. Long-term treatment with sildenafil in the three patients reduced mean pulmonary artery pressure by 14%, 41%, and 22%, respectively; in two patients, pulmonary vascular resistance was decreased by 52% and 55%. The 6MWD increased by 34%, 6%, and 29%, respectively. No significant systemic hypotension or decrease of arterial oxygen saturation was seen., Conclusion: Sildenafil therapy may be of benefit in patients with pulmonary arterial hypertension receiving long-term infusion of epoprostenol.

Purpose: Physicochemical and micromeritic characterization of chitinosans., Methods: Chitinosans subjected to N-deacetylation and depolymerization were characterized for degree of N-deacetylation (DD), molecular weight (MW), pK(a), particle size determination and morphology, tap/bulk density measurements, surface area determinations, and determination of flow properties., Results: The chitinosan DDs and MWs were dependent on the processing conditions and ranged from 66 to 89% and 2-522 kDa, respectively. Chitinosan particle sizes and shapes were dependent on drying conditions (range 8-465 microm). Spray-dried chitinosans were spherical and had smaller particle sizes than the non-spray-dried materials which were irregularly shaped particles. Higher density values were obtained for processed materials than those for the raw material. Lower specific surface areas were observed for non-spray-dried chitinosans (0.28-1.59 m(2)/g) than for spray-dried chitinosans (0.74-3.01 m(2)/g). Weight variation of chitinosan tablets indicated that spray-dried chitinosans possessed improved flow characteristics as compared with tray-dried chitinosans., Conclusions: The effect of drying method employed in chitinosan manufacture, i.e. spray versus tray drying, on the physicochemical and micromeritic properties of the resultant chitinosans were evaluated. Although the drying methods did not significantly influence the physicochemical properties, they affected the micromeritic properties of the resultant chitinosans.

Purpose: Application of spray-dried chitinosans as excipients for use in drug delivery systems was explored., Methods: Spray- and tray-dried chitinosans previously N-deacetylated and depolymerized were used. Directly compressed tablets (200mg) containing tetracycline, chitinosan, and magnesium stearate were prepared. The tablets were characterized for dimensions, weight, friability, crushing strengths, disintegration, and dissolution., Results: The tablet weights, thickness, and diameters were not affected by the chitinosan selected (P>0.05). Friability of tablets containing tray-dried chitinosans was generally higher (and crushing strengths were lower) than tablets containing spray-dried chitinosans. Chitinosan molecular weight, degree of N-deacetylation, and drying method used, significantly affected crushing strengths (P<0.0001). Disintegration times were affected only by the type of chitinosan (P<0.0001) but not by the drying method used (P>0.9). Dissolution from tablets was significantly affected by the chitinosan type (P<0.025), but not affected by the drying method (P>0.5)., Conclusions: Spray drying improved binding functionality of chitinosans, thereby enhancing the tablet crushing strength; however, friability, disintegration, and dissolution profiles were not significantly affected. The data obtained from this study support the usefulness of spray-dried chitinosans as excipients for use in drug delivery systems.

The purpose of this study was to examine the potential use of electrolytes to control naproxen sodium (I) release from chitinosan (II) tablets. An ANOVA was employed to evaluate the effects of molecular weight (MW) of II, electrolyte valence (EV), and pH of the dissolution medium on I's release. The intrinsic dissolution rates and saturation solubilities of I were determined at each of the pHs used. Directly compressed tablets were prepared from admixtures containing: I, NaCl, CaCl(2), or AlCl(3), Mg stearate, and II. The tablets were characterized for their dimensions, crushing strengths, friability, disintegration times, and in vitro dissolution profiles. The slopes of the log-log cumulative percent released-time curves (t=0-5 h) were compared using ANOVA. Based on the ANOVA, each of the variables-chitinosans, EVs, and pHs-significantly affected drug release (P<0.05). Besides the poor aqueous solubility of I, the factors possibly affecting drug release included: (a) the formation of a rate-limiting II gel barrier; (b) the interaction of I with ionized amino groups of II; (c) the effect of electrolyte on the II's gel barrier formation; and/or (d) decreased aqueous solubility of I in the presence of electrolyte.

Alkyl 2-imidazolyl disulfide compounds are novel antitumor agents, one of which is currently being evaluated in Phase I clinical trials. These molecules contain an unsymmetrical disulfide fragment, the lipophilic and electronic contributions of which are still not defined in the literature. Lipophilicity, ionization, and solubility of a number of alkyl 2-imidazolyl disulfides were studied. Based on the additivity of lipophilicity and ionization properties, the contribution of the unsymmetrical disulfide fragment to lipophilicity and ionization was elucidated. The unsymmetrical disulfide fragment contributed a Rekker's hydrophobic constant of 0.761 to the lipophilicity of these compounds and an approximated Hammett constant (sigma) of 0.30 to their ionization. The applicability of the general solubility equation (GSE) proposed by Jain and Yalkowsky in predicting the aqueous solubility of these analogs was evaluated. The GSE correctly ranked the aqueous solubilities of these compounds and estimated their log molar solubilities with an average absolute error of 0.35., (Copyright 2002 Wiley-Liss Inc.)

1-Methylpropyl-2-imidazolyl disulfide (MID) is a novel antitumor agent currently in Phase I clinical trials. The chromatographic behavior of MID and its potential impurity, degradation product, and metabolite 2-mercaptoimidazole (2MI) was studied under reversed-phase (RP) and normal-phase (NP) conditions. Both RP- and NP-HPLC separation methods were developed. RP-HPLC was validated as a stability-indicating assay for MID. NP-HPLC retained both MID and 2MI and pending further validation, could prove useful in the study of MID pharmacokinetics.

Belonging to the family of steroid hormones, glucocorticoids are essential for development and survival of vertebrates. The cellular response to glucocorticoids is attributed to the glucocorticoid receptor, which functions as a transcription factor. However, the majority of glucocorticoid-modulated genes lack a DNA binding site for the glucocorticoid receptor, raising the question of which mechanism mediates the responses to glucocorticoids. It has been suggested that besides direct DNA binding of the glucocorticoid receptor, interaction with members of other transcription factor families modulates the effect of the glucocorticoid receptor. However, the significance of such transcription factor interaction is not clear. In cultured human mesenchymal cells and peripheral blood leukocytes of human volunteers treated with glucocorticoids, we detected the formation of a complex between the GR and the CCAAT/enhancer binding protein alpha. In in vitro experiments, this interaction turned out to be responsible for the inhibitory action of glucocorticoids on lymphocytic and mesenchymal cell proliferation. Our results suggest that complex formation of the GR with C/EBPalpha accounts for a novel pathway of glucocorticoid action.

Background: Continuous intravenous treatment with epoprostenol significantly improves pulmonary haemodynamics and survival in patients with primary pulmonary hypertension (PPH). Its beneficial effect, however, may be blunted due to adverse effects such as catheter sepsis and systemic hypotension. Recent investigations have shown that inhaled iloprost is effective in the treatment of PPH. Based on their different pharmacokinetics, we hypothesised that the combination of intravenous epoprostenol and inhaled iloprost would be more efficacious than epoprostenol alone during acute testing in patients with PPH., Methods: The effect of a single dose of inhaled iloprost (30 microg total over 15 minutes) on pulmonary haemodynamics was examined in eight patients with PPH (initial non-responders to nitric oxide) who had considerable adverse effects during treatment with epoprostenol., Results: The combination of inhaled iloprost and intravenous epoprostenol significantly improved mean pulmonary artery pressure (MPAP), cardiac index (CI), mixed venous oxygen saturation (SvO2), and systemic arterial oxygen pressure (PaO2) compared with epoprostenol treatment alone. Mean systemic arterial pressure (MSAP) and pulmonary capillary wedge pressure (PCWP) remained unchanged., Conclusions: The pulmonary vasoreactivity shown by additional iloprost inhalation during effective epoprostenol treatment suggests that an improvement of treatment for pulmonary hypertension may be possible by combining vasoactive substances.

The vasoactive peptide angiotensin II is the principal effector of the renin-angiotensin system. It exerts mitogenic and growth-inhibiting effects in many target tissues, including renal mesangial cells. To investigate mechanisms of angiotensin II signaling in human mesangial cells, we explored the signal transducer and activator of transcription (STAT) pathway as a possible regulator of angiotensin II receptor-specific signaling. We tested whether angiotensin II could induce STAT activation and nuclear translocation of STAT proteins in human mesangial cells by electromobility shift assays and by immunostaining and confocal microscopy. We found that fetal human mesangial cells express STAT1,2,3,5, and 6 and that stimulation of these cells by angiotensin II results in rapid induction of STAT1 and STAT5 DNA-binding activity. This DNA-binding activity was identified as STAT5 for angiotensin receptor type 1 activation and STAT1 for angiotensin receptor type 2-mediated activation, as induction of STAT-DNA binding by angiotensin II could be differentially blocked by the angiotensin receptor type 1 blocker losartan and by angiotensin II receptor type 2 blocker PD 123,319. Angiotensin II also induced STAT1 and STAT5 tyrosine phosphorylation and nuclear translocation of activated STATs in a receptor subtype-specific manner. STAT activation thus appears to provide an important signaling pathway for angiotensin II-induced cellular responses., (Copyright 2001 Academic Press.)

This study evaluated and characterized the use of chitosan gels as matrices for electrically modulated drug delivery. Chitosan gels were prepared by acetylation of chitosan and subsequently hydrated to facilitate further studies. After determining the degree of deacetylation, hydrated and unhydrated gel formulations were characterized for their microviscosity and compression strength. In the electrification studies, gel mass variation, surface pH changes, and later, release-time profiles for neutral (hydrocortisone), anionic (benzoic acid), and cationic (lidocaine hydrochloride) drug molecules from hydrated chitosan gels were monitored in response to different milliamperages of current as a function of time. Hydrated gels had very similar microviscosity while exhibiting differences in the gel strength, results which are not inconsistent as they pertain to different aspects of the gel. The cumulative gel mass loss and rate of gel mass loss increased with an increase in the milliamperage (mA) of the applied current. Gel syneresis - principally involving electroosmosis and gel collapse - was pronounced, particularly at higher mAs and for chitosan gels with lower degrees of acetylation. The surface pH values of the gels were lower at the anode and higher at the cathode, in accordance with reports in the literature. The release of the model drugs from the gel matrix was in the order benzoic acid>hydrocortisone>lidocaine, which is consistent with the electrokinetically competing forces that are involved in these gels. Adequate characterization of electrical effects on formulation matrices, such as chitosan gels, is critical to the development of effective and reliable electrically modulated drug delivery systems.

The pathology of progressive pulmonary fibrosis combines injury, chronic inflammation and exaggerated, but futile organ repair. Models of experimental organ fibrosis such as bleomycin- or irradiation-induced lung fibrosis indicate that the continuous overexpression of major growth factors such as transforming growth factor beta 1 plays a major role in the tissue reorganization process and the modulation of the accompanying immune response. Moreover, this process is combined with a reorganization of the extracellular matrix that is likely to allow for the secondary loss of transcription of the interferon gamma gene. As a result, the cytokine pattern of the evolving chronic cellular immune response shifts to the so-called T helper 2 type. Recent investigations have demonstrated that this poorly balanced immune response is a characteristic feature of human progressive lung fibrosis such as idiopathic pulmonary fibrosis. Based on the strong antifibrotic properties of interferon gamma, we combined low-dose glucocorticoids with interferon gamma-1b for the treatment of idiopathic pulmonary fibrosis, a relentlessly progressive form of human pulmonary fibrosis. This pilot investigation demonstrated that interferon gamma is able to improve pulmonary function in patients with idiopathic pulmonary fibrosis while at the same time counterbalancing mechanisms of exaggerated wound repair, such as the overinduction of transforming growth factor beta 1.

Background: Broncho-Vaxom (OM-85 BV) is known to support respiratory tract resistance to bacterial infections. In vivo and in vitro studies in animals and humans have shown that the action of the drug is based on the modulation of the host immune response, and it has been found to upregulate interferon gamma (IFN-gamma) and interleukin (IL)-2, IL-6, and IL-8. These immunomodulatory effects of the compound may explain its stimulation on T helper cells and natural killer cells. Following earlier findings that OM-85 BV induces the synthesis of IL-6, a study was undertaken to investigate its possible effect on other gp130 binding cytokines including IL-11, IL-12, leukaemia inhibitory factor (LIF), oncostatin M (OSM), and ciliary neutrophil factor (CNTF). Its modulation of the corresponding receptors of the above mentioned cytokines and of the signal transducer gp130 in human pulmonary fibroblasts and peripheral blood lymphocytes was also studied., Methods: Transcription of cytokines was assessed by Northern blot analysis. Secretion of cytokines was analysed using commercially available enzyme linked immunosorbent assay kits. Cytokine receptors and gp130 proteins were determined by Western blot analysis., Results: OM-85 BV increased the expression of IL-11 in human lung fibroblasts, but not in lymphocytes, in a dose and time dependent manner by maximal fivefold within 20 hours. The compound inhibited serum induced IL-12 expression in peripheral blood lymphocytes but did not induce OSM, LIF, or CNTF at any concentration. In lung fibroblasts the expression of the IL-6 receptor was enhanced fourfold at a concentration of 10 microg/ml OM-85 BV while that of the IL-11 receptor was not altered. In peripheral blood lymphocytes LIF receptor alpha expression was downregulated in the presence of 10 microg/ml OM-85 BV. At a concentration of 10 microg/ml OM-85 BV enhanced gp130 gene transcription fivefold and increased gp130 protein accumulation in cell membranes by 2.5 times., Conclusion: In vitro OM-85 BV exerts immunomodulatory action via modulation of the signal transducer gp130 and gp130 binding cytokines. The increase of IL-6 and IL-11 may explain enhanced T and B cell activity, immunoglobulin synthesis, and IgM to IgG switch. Suppression of IL-12 and LIF receptor-alpha further contributes to organ protection. With regard to gp130 mediated signalling of the investigated cytokines, OM-85 BV modifies the host immune response towards an increased sensitisation of cells to gp130 binding proteins.

Chitosan was physicochemically modified for its potential use as a matrix for an implantable antibiotic delivery system that could sustain bactericidal concentrations in the vicinity of an implant or prosthesis. Deacetylation and depolymerization of chitosan were implemented in order to increase the number or accessibility of the reactive amino groups on the polymer backbone for better polymer-drug interaction. The deacetylation process involved reaction of particulate chitosan/depolymerized chitosan with alkali. The rate of deacetylation of chitosan was directly proportional to the reaction temperature up to 80 degrees C; beyond 80 degrees C, rapid degradation of the polymer occurred. The depolymerization of chitosan involved acid digestion of the polymer followed by application of mechanical agitation. This depolymerized product, although water insoluble, possessed a molecular weight that was one to two orders of magnitude lower than that of commercially available chitosans. These products not only exhibited improved reactivity, but also showed increased crystallinity when compared with the parent chitosan. The reactivity was found to be inversely proportional to chitosan's molecular weight. The depolymerization and deacetylation treatments afforded formation of chitosan having a greater number of amino groups available for interactions with the anionic actives.

E-selectin is an endothelial-specific surface protein, which is transiently expressed in response to inflammatory cytokines and plays an important role in the recruitment of leukocytes to the site of infection. The effect of two fluoroquinolones, ciprofloxacin (cipro) and trovafloxacin (trova), on the interleukin-1 (IL-1)-dependent activation of E-Selectin was studied on human umbilical vein endothelial cells (HUVEC) in vitro. Trova, at 80 microg/ml, affected the transient expression of E-selectin mRNA after pro-inflammatory stimulation with IL-1 leading to a sustained expression over 24 h. Surface expression of E-selectin remained upregulated after 24 h in a higher percentage of cells when they were activated in the presence of trova, as determined by flow cytometry analysis. Moreover, the concentration of shedded soluble E-selectin (sE-selectin) in the cell supernatant increased by 3.5 fold compared to those stimulated in the presence of cipro or without fluoroquinolones. Analogously, the antiproliferative effect of trova on endothelial cells was found to be more pronounced compared to cipro leading to an accumulation of cells arrested in G1-phase. These data provide evidence that accumulation of high concentration of trova in vivo in inflamed tissue might alter inflammatory responses.

Objective: To assess whether long term treatment with epoprostenol might restore primary non-responsiveness to nitric oxide (NO) in patients with primary pulmonary hypertension., Methods: Seven patients with primary pulmonary hypertension receiving intravenous epoprostenol continuously because of failure of NO to influence pulmonary haemodynamics during initial testing were followed over a period of 13-29 months. Afterwards, acute vascular reactivity towards NO was tested again during right heart catheterisation., Results: Administration of NO after continuous epoprostenol treatment for a mean period of 18 months improved arterial oxygen saturation (p < 0.01) and cardiac index (p < 0.05), and decreased mean pulmonary artery pressure (p < 0.01) and total pulmonary vascular resistance (p < 0.01) in patients previously unresponsive to NO., Conclusions: Long term treatment with epoprostenol reverts initial refractoriness to NO in patients with primary pulmonary hypertension. Thus the addition of NO to epoprostenol treatment might cause further improvement in the course of the disease.

Cationic lipid-based gene delivery systems have shown promise in transfecting cells both in vitro and in vivo. However, these systems tend to form aggregates in liquid formulation during storage, which has limited their clinical applications. As a result, lyophilization of these systems has recently become a subject of increasing interest. In this paper, lyophilization of LPD, a novel cationic lipid-based gene delivery system, was studied. Both particle size and transfection efficiency could be preserved in the presence of sufficient amount of appropriate lyoprotectant. A series of monosaccharides and disaccharides, including dextrose, galactose, mannose, lactose, maltose, sucrose and trehalose, were evaluated for their lyoprotective effect and disaccharides showed more superior protection to monosaccharides. The effect of different freezing protocols for lyophilization was also evaluated and no significant difference was found. However, for freeze-thawing, fast freezing caused less aggregation. Finally, nonlyophilized LPD and LPD lyophilized with 10% sucrose were stored at different temperatures and their stability was followed for eight weeks. Lyophilized LPD could be stored at room temperature without significant change in particle size or loss of transfection efficiency.

Laminin, a cell adhesion protein, consists of three peptide chains (alpha-1, beta-1 and gamma-1). The beta-1 chain contains a Tyr-Ile-Gly-Ser-Arg (YIGSR) sequence that has been found to inhibit experimental metastasis in mice. We have prepared a hybrid of a water-soluble chitosan and a laminin-related peptide, and have examined its inhibitory effect on experimental metastasis in mice. A laminin-related peptide, acetyl-Tyr-Ile-Gly-Ser-Arg-betaAla-OH (Ac-YIGSRbetaA-OH), was prepared by a solid-phase method. Ac-YIGSRbetaA-OH was then reacted with a water-soluble chitosan. BetaAla is a spacer and was placed to avoid racemization of the Arg residue when the peptide was coupled with chitosan. Although chitosan has amino groups, they did not react with the peptide. Four methods were tried to achieve a coupling reaction, the diphenylphosphoryl azide method, the diisopropylcarbodiimide/1-hydroxybenzotriazole method, the water-soluble carbodiimide (WSC), and the 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) method, but all four methods were unsuccessful. Therefore, a small spacer, tert-butyloxycarbonyl-Gly, was intercalated in chitosan, by the TBTU method, to facilitate its coupling with the peptide. After removal of the protecting group, the Gly-chitosan was coupled with Ac-YIGSRbetaA-OH by the water-soluble carbodiimide method to give Ac-YIGSRbetaAG-chitosan. Conjugation of the peptide with the larger chitosan molecule did not reduce the inhibitory effect of the peptide on experimental metastasis in mice, it actually potentiated the antimetastatic effect, demonstrating that chitosan may be effective as a drug carrier for peptides.

Background and Methods: Patients with idiopathic pulmonary fibrosis have progressive scarring of the lung and usually die within four to five years after symptoms develop. Treatment with oral glucocorticoids is often ineffective. We conducted an open, randomized trial of treatment with a combination of interferon gamma-1b, which has antifibrotic properties, and an oral glucocorticoid. We studied 18 patients with idiopathic pulmonary fibrosis who had not had responses to glucocorticoids or other immunosuppressive agents. Nine patients were treated for 12 months with oral prednisolone alone (7.5 mg daily, which could be increased to 25 to 50 mg daily), and nine with a combination of 200 microg of interferon gamma-1b (given three times per week subcutaneously) and 7.5 mg of prednisolone (given once a day)., Results: All the patients completed the study. Lung function deteriorated in all nine patients in the group given prednisolone alone: total lung capacity decreased from a mean (+/-SD) of 66+/-8 percent of the predicted value at base line to 62+/-6 percent at 12 months. In contrast, in the group receiving interferon gamma-1b plus prednisolone, total lung capacity increased (from 70+/-6 percent of the predicted value at base line to 79+/-12 percent at 12 months, P<0.001 for the difference between the groups). In the group that received interferon gamma-1b plus prednisolone, the partial pressure of arterial oxygen at rest increased from 65+/-9 mm Hg at base line to 76+/-8 mm Hg at 12 months, whereas in the group that received prednisolone alone it decreased from 65+/-6 to 62+/-4 mm Hg (P<0.001 for the difference in the change from baseline values between the two groups); on maximal exertion, the value increased from 55+/-6 to 65+/-8 mm Hg in the group that received combined treatment and decreased from 55+/-6 mm Hg to 52+/-5 mm Hg in the group given prednisolone alone (P<0.001). The side effects of interferon gamma-1b, such as fever, chills, and muscle pain, subsided within the first 9 to 12 weeks., Conclusions: In a preliminary study, 12 months of treatment with interferon gamma-1b plus prednisolone was associated with substantial improvements in the condition of patients with idiopathic pulmonary fibrosis who had had no response to glucocorticoids.

Biodegradable gadopentetic acid (Gd-DTPA)-loaded chitosan microparticles (Gd-microCPs) were prepared as a device for gadolinium neutron-capture therapy (Gd-NCT) by a novel emulsion-droplet coalescence technique: a water-in-oil (w/o) emulsion A containing chitosan and Gd-DTPA in droplets and a w/o emulsion B containing NaOH in droplets were mixed and stirred to solidify chitosan as a result of collision and coalescence between droplets of each emulsion. Gd-microCPs prepared by using 100% deacetylated chitosan in 25% Gd-DTPA solution were 4.1 microns (non-lyophilized) and 3.3 microns (lyophilized) in mass median diameter, and were 3.4% in gadolinium content, corresponding to 11.7% as Gd-DTPA. The particle size and gadolinium content of Gd-microCPs were not affected by Gd-DTPA concentration in the chitosan medium. However, the deacetylation degree of chitosan influenced the particle size; as the deacetylation degree of chitosan decreased, the particle size increased. The incorporated Gd-DTPA was not released entirely from Gd-microCPs in an isotonic phosphate buffered saline solution despite the high water-solubility of Gd-DTPA (less than 0.8% with every type of Gd-microCPs). These results indicated that ion-complex formation might be contributable to incorporation of Gd-DTPA. As a preliminary study, it was confirmed that the loss of gamma-ray emission by gadolinium-loading in microparticle was negligible in the thermal neutron irradiation test in vitro. These results suggested that Gd-microCPs could be a useful device for intratumoral injection into solid tumor on Gd-NCT.

Background: Calcium channel blockers (CCB) of all subclasses: the dihydropyridines, benzothiazepines, and phenylalkylamines, at nanomolar concentrations, have been shown to up-regulate interleukin-6 (IL-6) mRNA. We investigated the underlying molecular mechanism responsible for IL-6 induction in response to the CCB amlodipine, diltiazem, and verapamil in primary human vascular smooth muscle cells (VSMC)., Methods and Results: All 3 CCB directly activated transcription of the human IL-6 gene in primary human VSMC in a time- and dose-dependent manner, as demonstrated by luciferase reporter gene assays using a 651-bp fragment of the human IL-6 gene promoter. Deletion analysis of the IL-6 promoter revealed that CCB inducible promoter activity was localized to a 160-bp fragment directly upstream of the transcriptional start site of the IL-6 gene. Known transcription factor consensus sequences within this fragment include a NF-IL6 and a NF-kappaB site. Site-directed mutagenesis suggested that both transcription factors had positive regulatory activity and cooperatively transmitted induction of the IL-6 gene by CCB. The data are confirmed by electrophoretic mobility shift analyses using nuclear extracts from CCB-stimulated and control primary VSMC. CCB of all subclasses increased DNA binding of NF-IL6 and NF-kappaB as early as 30 minutes after stimulation with the drugs. This effect was independent of intracellular calcium concentrations because calcium-free medium did not increase NF-IL6 or NF-kappaB activity., Conclusions: The results demonstrate that CCB of all 3 subclasses are capable of activating NF-IL6 and NF-kappaB. CCB may thus directly regulate cellular functions by affecting the activity of transcription factors independent of changes of intracellular calcium concentrations, an observation that is of interest considering the biological effects induced by CCB.

The term 'chitinosans' embraces the spectrum of acetylated poly(N-glucosamines) ranging from chitin to chitosan. Chitinosans (I), at acidic pH, have protonated amines which can interact with oppositely charged drug ions and, thereby, modify drug release from drug delivery systems. Tablets were compressed from a physical mixture containing salicylic acid (II) as the model drug, I, and magnesium stearate. Five commercial I compounds, varying in degree of deacetylation and molecular weight, were selected. Tablets were compressed at 5000, 10 000, and 15 000 psig using a Carver and a single punch tablet press. The differential scanning calorimetry thermograms provided evidence of I-II interaction in the powder blend. Analysis of variance (ANOVA) indicated that the compression pressure did not significantly affect the crushing strength (CS) or the release profile of II from the I-matrix tablets (P?0.05). Furthermore, the ANOVA also indicated that the tablet press used during manufacture did not affect the above properties (P?0.05); however, the chitinosans significantly affected the CS as well as the release profile of II from I-matrix tablets (P<0.05). This study provides further evidence for the use of commercial I compounds as excipients for use in modified release drug delivery systems., (Copyright.)

The glucocorticoid receptor (GR) is a ubiquitously expressed transcription factor present in most cell types. Upon ligand binding, the GR is activated and translocates into the nucleus where it transmits the anti-inflammatory actions of glucocorticoids. Here, we describe the ligand-independent activation of GR by the beta2-adrenergic receptor (beta2-AR) agonists, salbutamol and salmeterol, in primary human lung fibroblasts and vascular smooth muscle cells. Immunohistochemistry demonstrated expression of GR and the beta2-AR by fibroblasts and vascular smooth muscle cells. Treatment of the cells with the beta2-AR agonists, salbutamol or salmeterol, resulted in translocation of GR into the nucleus beginning at 30 min, as shown by immunohistochemistry and Western blotting of cytosolic and nuclear cell extracts. In comparison, activation of GR induced by the corticosteroids dexamethasone and fluticasone occurred at the same time after treatment (30 min) but resulted in a more complete depletion of GR from the cytosolic compartment. Electrophoretic mobility shift assays confirmed that nuclear GR, activated by both beta2-AR agonists and glucocorticoids, actively bound to the GR consensus sequence (GR element). Functional activation of the GR was confirmed by a Luciferase reporter gene assay, using a GR driven promoter fragment from the p21((WAF1/CIP1)) gene. The effects of the beta2-AR agonists, salbutamol and salmeterol, were dependent upon binding to the beta2-AR, because blocking of beta2-AR with propranolol abrogated GR activation. GR activation appeared to involve cAMP. In summary, these data show that beta2-AR agonists are potent activators of GR. Ligand-independent activation of GR by beta2-AR agonists may substantially mediate the anti-inflammatory actions of these drugs observed in vitro and in vivo.

Immune response and restructuring of tissue during organ fibrosis mutually influence each other. It has become evident that the immunomodulatory properties of lining cells of the lung, such as bronchial or alveolar epithelial cells or pulmonary endothelial cells exert a major influence on the acute and chronic activation of the immune system. On the other hand, recent data obtained under in vivo conditions, suggest that the process of mesenchymal organ remodelling during inflammation not only causes organ fibrosis, but may actually perpetuate the process of chronic pulmonary inflammation due to its immunosuppressive effects. In this short review, two examples for this reciprocal influence are discussed.

The formation of atherosclerotic lesions is characterized by invasion of vascular smooth muscle cells (VSMC) into the tunica intima of the arterial wall and subsequently by increased proliferation of VSMC, a process apparently restricted to the intimal layer of blood vessels. Both events are preceded by the pathological overexpression of several growth factors, such as platelet-derived growth factor (PDGF) which is a potent mitogen for VSMC and can induce their chemotaxis. PDGF is generally not expressed in the normal artery but it is upregulated in atherosclerotic lesions. We have previously shown that PDGF-BB specifically stimulates proliferating VSMC to secrete a 340 kDa hyaluronic acid (HA-340). Here, we present evidence regarding the biological functions of this glycan. We observed that HA-340 inhibited the PDGF-induced proliferation of human VSMC in a dose-dependent manner and enhanced the PDGF-dependent invasion of VSMC through a basement membrane barrier. These effects were abolished following treatment of HA-340 with hyaluronidase. The effect of HA-340 on the PDGF-dependent invasion of VSMC coincided with increased secretion of the 72-kDa type IV collagenase by VSMC and was completely blocked by GM6001, a hydroxamic acid inhibitor of matrix metalloproteinases. HA-340 did not exert any chemotactic potency, nor did it affect chemotaxis of VSMC along a PDGF gradient. In human atheromatic aortas, we found that HA-340 is expressed with a negative concentration gradient from the tunica media to the tunica intima and the atheromatic plaque. Our findings suggest that HA-340 may be linked to the pathogenesis of atherosclerosis, by modulating VSMC proliferation and invasion.

Vascular smooth muscle cells (VSMC), under conditions of induced proliferation, similar to those involved in atherosclerosis, secrete an acidic glycan, 82% of which exhibits structural homology with hyaluronic acid (HA), has a molecular mass of 340 kDa (HA-340) and inhibits VSMC proliferation in vitro. In this study, the expression of glycans was investigated in human atheromatic aortas and evidence is presented that a HA molecule, similar to HA-340, is distinctly expressed in all aortic layers. The isolation of the glycans from human aortas was performed after homogenization of the individual aortic layers (atheromatic plaque, tunica intima, tunica media and tunica adventitia), by lipid extraction and extensive digestion with pronase and DNase. The total glycans were purified from the digestion products by gel filtration on Sephadex G-25 and fractionated on a Superose 6 column. Enzymatic treatment of the ensuing glycan fractions with all known glycosaminoglycan-degrading enzymes, followed by electrophoresis on polyacrylamide gradient gels and cellulose acetate membranes, revealed that, in addition to HA, the tunica intima and the atheromatic plaque also contained dermatan sulfate, while the tunica media and the tunica adventitia also contained chondroitin sulfates and heparan sulfate. The highest concentration of the human aorta HA was found in the tunica media, exhibiting a negative concentration gradient from the tunica media to the atheromatic plaque. Investigation of the biological function of the human aorta HA revealed that this molecule acts as a negative regulator on the PDGF-induced VSMC proliferation and as a positive regulator on the PDGF-induced VSMC migration. The differential expression of HA within the aortic layers correlates with the biological function attributed to this acidic glycan and associates it with key events in the progression of atherogenesis.

Vascular smooth muscle cells (VSMC) are involved in the pathogenesis of hypertension and coronary artery disease. Amlodipine, a calcium channel blocker of the dihydropyridine type, is widely used in the therapy of these diseases, and has been shown to reduce the progression of the underlying pathophysiological mechanisms, such as atherosclerosis and restenosis. Research on the impact of calcium channel blockers on cell behavior has revealed an antiproliferative effect on VSMC. Cell proliferation is tightly controlled by permanent interaction of cells with their surrounding microenvironment, the extracellular matrix (ECM). The ECM is subjected to a continuous turnover and implicated in (i) stabilization and compartmentalization of tissue architecture and (ii) local binding and preservation of growth factors and cytokines. These growth factors and cytokines can be released during degradation of the ECM, and can function as local inflammatory factors without de novo synthesis. In this context, we assessed the effects of amlodipine on the composition of the ECM and related factors. We investigated the effects of amlodipine on (i) the regulation of cellular cholesterol metabolism, (ii) the activation of genes encoding for inflammatory factors, (iii) gene expression and turnover of ECM compounds, and (iv) the activity of matrix-degrading enzymes. Most of these effects of calcium channel blockers require direct induction of gene expression. In this respect, we demonstrate that amlodipine increases expression of the cytokine interleukin-6 by directly activating the respective gene promoter in human VSMC.

The purpose of this study was to evaluate the potential utility of chitosan (I) in inhibiting diclofenac sodium (II) release in the gastric environment from a directly compressible tablet formulation. I, subjected to depolymerization to improve its microcrystallinity and subsequent compressibility, was then used to prepare tablets of II. A full-factorial design was employed to evaluate the effects of degree of N-deacetylation of I, and the pH and ionic strengths, mu, of the dissolution media on drug release. Directly compressible tablets were prepared from admixtures of 25 mg of II, 174 mg of I of various degrees of N-deacetylation (74, 87, and 92%), and 1 mg of magnesium stearate. The in vitro dissolution studies were performed using aqueous buffers (pHs 1.2, 3.8, and 6.8, and mu of approximately 1.0 and 0.1). The slopes of logarithmically transformed cumulative percent released-time curves (from t = 0 to t = 5 hr) were compared. Analyses of variance performed using SAS indicated that the degree of N-deacetylation of chitosan significantly affected drug release at pHs 1.2 and 6.8 (p < 0.0001). An increase in the pH of the dissolution medium resulted in an increase in drug release (p < 0.0001). The ionic strength of the dissolution medium did not significantly affect drug release at any of the pHs studied (p > 0.198). Besides the poor aqueous solubility of II, the two factors possibly affecting the drug release in the acidic environment were (a) the formation of a rate-limiting chitosan gel barrier; and (b) the ionic interaction of II with ionized amino groups of I.