Multiparameter Optimization of Naphthyridine Derivatives as Selective α5-GABAA Receptor Negative Allosteric Modulators.

The discovery and characterization of novel naphthyridine derivatives with selective α5-GABAAR negative allosteric modulator (NAM) activity are disclosed. Utilizing a scaffold-hopping strategy, fused [6 + 6] bicyclic scaffolds were designed and synthesized. Among these, 1,6-naphthyridinones were identified as potent and selective α5-GABAAR NAMs with metabolic stability, cardiac safety, and beneficial intellectual property (IP) issues. Relocation of the oxo acceptor function and subsequent modulation of the physicochemical properties resulted in novel 1,6-naphthyridines with improved profile, combining good potency, selectivity, ADME, and safety properties. Besides this, compound 20, having the most balanced profile, provided in vivo proof of concept (POC) for the new scaffold in two animal models of cognitive impairment associated with schizophrenia (CIAS).

Monitoring M-BCR-ABL expression level in CML patients by RQ-PCR: experience of a single Center.

UNLABELLED: Chronic myelogenous leukemia (CML) is characterized by the Philadelphia chromosome and the BCR-ABL fusion gene that encodes an abnormal tyrosine kinase. Development of specific tyrosine kinase inhibitors completely changed the management of these patients. MATERIALS AND METHODS: Between April 2008 and July 2012, at the Molecular Biology Laboratory, University of Medicine and Pharmacy of Targu Mures, Romania, we monitored the M-BCR-ABL transcript level by real time quantitative PCR in case of 15 CML patients diagnosed at the Hematology and Transplant Center of Targu Mures. RESULTS: Modification of M-BCR-ABL expression level shows statistically significant correlation (p=0.013) with the clinical course of these patients. CONCLUSIONS: Molecular biology techniques have an important role in monitoring CML patients and regular analysis is recommended.

Histopathological, immunophenotypic and clinical particularities and evolution of a case of hepatosplenic T-cell lymphoma in transformation to leukemia.

We present the possibilities of diagnosis correlating the pathological, immunophenotyping and clinical aspects of a rare case of T-cell lymphoma in a 23-year-old patient with leukemic transformation. In our consideration, it is very important to describe this case because in the literature there are very few cases presented and the treatment of this type of lymphoma does not present optimal results, the evolution of the patients being from three months to two years. The treatment modality that gives the possibility to prolong survival and cure is hematopoietic stem cell transplantation.

Investigation of human pharmacoscintigraphic behavior of two tablets and a capsule formulation of a high dose, poorly water soluble/highly permeable drug (efavirenz).

Human pharmacoscintigraphic behavior of two tablets and a capsule formulation of a high dose, poorly water soluble, highly permeable, micronized drug (efavirenz) was investigated. The tablets and capsule, prepared with samarium oxide and neutron activated to produce radioactive samarium-153, were evaluated for their in vivo disintegration and gastrointestinal (GI) transit in healthy subjects under fasted condition. Scintigraphic images were acquired to coincide with blood sampling times to assess the plasma concentration-time profile in relation to in vivo disintegration and GI transit. The mean gastric emptying times were approximately the same for all three formulations. Although in vivo dosage form disintegration was faster for Tablet A as compared to Tablet B and was similar between Tablet A and the capsule, Tablet A showed a slower rate and extent of drug absorption than Tablet B and the capsule. The results of this study eliminated the initial hypothesis that the difference in in vivo performance between the two tablet formulations is due to a different rate of in vivo disintegration and suggest that for this drug the in vivo dissolution rate of the drug from its disintegrated dosage form was a more important factor affecting the rate and extent of drug absorption.

Management of pulmonary arterial hypertension associated with congenital heart disease.

Congenital heart diseases are the most common congenital malformations and account for about eight cases per 1000 births and are often associated with pulmonary arterial hypertension. Increased shear stress and the excess flow through the pulmonary vascular bed due to a systemic-to-pulmonary shunt lead to the development of pulmonary vascular disease and an increase in pulmonary vascular resistance. Without surgical repair approximately 30% of patients develop pulmonary vascular disease. Eisenmenger syndrome represents the extreme end of pulmonary arterial hypertension with congenital heart disease. We summarized the current therapeutic options for pulmonary arterial hypertension; conventional treatments including calcium channel blockers, anticoagulation, digitalis, diuretics, and new treatment: prostacyclin, bosentan, sildenafil, ambrisentan. Preliminary data of new therapies are encouraging with disease significantly improved natural history, but there is need for more evidence-based data.

Current developments in interventional treatment of total terminal aortic occlusions--laser, stenting and balloon angioplasty: experience of cardiology clinic of Târgu-Mures.

UNLABELLED: The importance of interventional procedures in the complex treatment of peripheral arterial diseases is continuously increasing. In the current practice of our clinic, association of balloon angioplasty, laser angioplasty and arterial stenting in reconstruction of iliac arteries led to superior results in the latest years, these methods 11:42 PM 11:42 PM 11:42 PM being proved as an alternative to surgical interventions. In this article, we present several cases in which current indications for laser angioplasty were extended to target occlusions located in the terminal abdominal aorta. METHODS: 106 consecutive primary iliac interventions were performed on 88 patients with iliac or aortoiliac obstructive diseases, in the period September 2001 - October 2005, at the University of Medicine and Pharmacy of Târgu-Mures, Romania, Clinic of Cardiology. Five of these patients (4 males, 1 female) presented occlusions of terminal aorta, in whom interventional treatment (peripheral transluminal angioplasty, laser angioplasty and stenting) was performed. Three cases presented total occlusion of terminal aorta, without any visualization of iliac arteries, and 2 cases presented occlusion of one aortoiliac axis, starting from terminal aorta. RESULTS: In all cases, complete repermeabilisation of aortoiliac axes was achieved, without complications. In all patients we recorded a significant improvement of symptomatology, and arterial Doppler showed an increase of Doppler ankle/brachial index in average from 0.4 up to 0.95. No complications have been recorded so far. CONCLUSION: Extension of classical indications of interventional treatment for balloon and laser angioplasty to occlusions located in terminal aorta is possible when the procedure is performed by an experienced team. Interventional techniques, having a superior applicability in practice, good results, low complication rates, and decreasing the hospitalization times, could be applied in the future to a larger extent, targeting also aortic occlusions.

Interventional treatment with autoexpandable stents in iliofemoral arterial diseases.

UNLABELLED: The importance of peripheral arterial diseases is revealed by statistical data, which showed a frequency of arterial diseases equal to the one of stable angina Traditional treatment of these patients was the surgical bypass, but an alternative therapy in these cases is the interventional treatment. Arguments for this option could be: it is less expensive, it decreases the hospitalization time, it does not require general anesthesia, and complications are less frequent and less severe. Interventional treatment is recommended especially in cases of short, isolated lesions of great vessels. During the last years, indications for interventional treatment were expanded to more difficult and complex cases, due to the advances in technology of endoluminal treatment products and the recently introduced laser angioplasty technology. MATERIAL AND METHOD: Among the interventional techniques we apply in our clinic, we mention: percutaneous transluminal angioplasty, intraarterial stent implantation, laser angioplasty and intraarterial thrombolysis, some of them peformed with IVUS control. In a period of 14 years we examined a total number of 6,532 patients suffering from peripheral arterial obstructive diseases. In the past 3 years, in our new laboratory of interventional cardiology, new procedures have been introduced in the algorithm of interventional treatment, such as laser angioplasty. Invasive diagnosis performed in the Cardiology Clinic consisted in aortography in 746 cases and peripheral arteriography in 2035 cases. Interventional treatment consisted in percutaneous transluminal angioplasty (1.240 procedures, 756 performed in the latest 3 years), intraarterial thrombolysis (214 procedures), laser angioplasty (since June 2002-130 procedures performed) and stent implant (since 2001-61 cases). Axillar approach was also introduced in 2001 and was applied in 23% of cases. RESULTS: We recorded a 76.5% success rate using only PTA for repermeabilisation of the lower limb arteries. Association of intraarterial thrombolysis increased the success rate to 91%. Using laser angioplasty and autoexpandable stent implantation, the success rate achieved was 100%. CONCLUSION: Interventional treatment is an important alternative in the complex algorithm of treatment in PAOB. Intraarterial stenting significantly improves the immediate and the long term results of interventional treatment, and autoexpandable stents with thermal memory show superior results. Laser angioplasty is an adjuvant method which significantly improves the results of interventional treatment. In all these methods, a very important role plays the good cooperation of the team formed by cardiologist, angiologist and vascular surgeon.

Intra-arterial segmental thrombolysis in patients with arterial embolism of cardiac origin.

OBJECTIVE: It is well known that in the evolution of cardiac diseases, thromboembolic accidents are quite frequent. In patients with acute peripheral ischaemia, surgical treatment is usually the procedure of choice, but in some circumstances some of these patients cannot benefit from the surgical treatment. Conservative treatment rarely leads to satisfactory results. An alternative of therapy is the thrombolysis, but administration of Streptokinase in systemic dose can lead to serious thromboembolic accidents and hemorrhage. Intra-arterial administration of the drug, in small doses, can eliminate this risk. The aim of this study was to demonstrate the efficacy of intra-arterial thrombolysis in patients with cardiac diseases complicated with peripheral arterial emboli. METHOD: In the period 1984-1997, we performed a number of 84 intra-arterial thrombolyses. Sixty-one of them were performed in case of chronic or acute arterial obstruction of the inferior limbs, occurring in the evolution of chronic arterial disease, 14 in the patients with acute obstruction caused by emboli from cardiac cavities, and 9 in the patients with arterial embolism of other origin. We applied this procedure infusing Streptokinase intraarterially, continuously, directly and progressively in the thrombus, with a rate of 2-4000 unit/min, and a total dose more than 100,000-120,000 units. All patients had been consulted previously in a surgical unit and for different reasons surgical treatment was not indicated. RESULTS: We succeeded to repermeabilise the entire arterial route at all the patients (fact demonstrated by the clinical and Doppler examinations). We obtained complete primary repermeabilisation in 79% cases (11 cases), and repermeabilisation at 24 hours in all cases. We did not record major complications during this procedure. CONCLUSIONS: At the cases we studied (a small number), this method seems to be an alternative of therapy with good results in the restoration of obstructed arterial circulation. Intra-arterial administration of Streptokinase, in small doses, can eliminate the haemorrhagic and thromboembolic risks that appear in case of systemic administration of the drug.

Endomyocardial biopsy in diagnosis of myocardial diseases.

In the past years, diagnosis of myocardial diseases became less difficult. A major contribution in this direction has the recent development of diagnosis methods. One of the most recent diagnosis procedures is the endomyocardial biopsy, which manages directly through the histologic examination to establish a clear diagnosis in myocardial diseases. This method provides faithful morphological data about the pathological changes in the myocardium. The aim of our study was to underline the importance of endomyocardial biopsy in an accurate diagnosis of different cardiomyopathies. In the period of 12 years (1986-1998), in the Cardiovascular Department of the First Medical Clinic Târgu-Mures, Romania, were admitted 137 patients suffering from different cardiomyopathies. We performed a number of more than 100 endomyocardial biopsies on 25 of them, obtaining in each case 3 to 5 samples of endomyocardial tissue from the right ventricle. In all cases the Cordis bioptome was introduced in the right ventricle via femoralis vein. The complications were minor: ventricular extrasystoles. In all cases, we succeeded to obtain enough tissue for the histopathological examination, from different areas of RV. Histologic examination showed in all cases characteristic aspects of different cardiomyopathies. helping to clarify the diagnosis. After performing Endomyocardial Biopsy, we record an important increase of dilated cardiomyopathy percentage of diagnosis, from 40% to 72%. In patients with dilated cardiomyopathy, we observed a good correlation between hemodynamical data (Ejection Fraction, Left Ventricle End-Diastolic Pressure, etc.) and the index of myocardial damage, especially the degree of interstitial fibrosis. Using this method it is possible to distinguish different types of cardiomyopathies, such as: primary dilated cardiomyopathy, eosinophilic cardiomyopathy, myocarditis, idiopathic hypertrophic cardiomyopathy. Because the complications of this procedure are insignificant, and because of its important benefit for an accurate diagnosis, we recommend to apply this method for different cardiomyopathies.

Myocardial fibres in pulmonary veins--possible compensatory factor in dilated cardiomyopathy.

It is well known in the literature that myocardial tissue is present in different degrees in pulmonary veins, but the eventual role of this myocardial tissue in pulmonary veins is not very clear at this moment. We presumed that one of the compensatory mechanisms in heart failure could be represented by the development of this myocardial tissue in the pulmonary veins. We studied the extension of this myocardial tissue in patients with dilated cardiomyopathy (DCM). We performed a histologic examination of the myocardial tissue from the pulmonary veins, in patients with heart failure in advanced stages. These patients died in the hospital and we obtained the pulmonary tissue for examinations during the autopsy. At the border between the media and the adventitia of the pulmonary vein, the myocardial tissue is present and is well developed. Some of the fibers have a sinuous course, others present a longitudinal aspect, especially in the external layers. In some sections bundles and bands of muscle fibers are present. In the sections where no myocardial tissue was shown, the smooth muscular fibers were very numerous. The necroptic histologic studies showed different degrees of hypertrophy of the myocardial tissue in the pulmonary veins, in the patients with heart failure in advanced stages. We observed that dilatation degree of cardiac cavities and decrease of the ejection fraction correlates with hypertrophy degree of the myocardial tissue in the pulmonary veins. This can be an argument for the compensatory role of this hypertrophy.

Pharmacokinetic interactions of moricizine and diltiazem in healthy volunteers.

Sixteen healthy male volunteers completed a nonrandomized, sequential, three-phase study. The three phases were 1) moricizine at 250 mg every 8 hours for 7 days with 12 days washout; 2) diltiazem at 60 mg every 8 hours for 7 days; and 3) concomitant administration of moricizine at 250 mg and diltiazem at 60 mg every 8 hours for 7 days. The plasma concentration-time profiles were obtained at the end of each phase for moricizine, diltiazem (with its metabolites desacetyl-diltiazem and N-desmethyl-diltiazem), and both when administered together. Under steady-state conditions, there was a two-way (opposing) pharmacokinetic drug interaction when moricizine and diltiazem were coadministered in healthy volunteers. Both maximum plasma concentration (Cmax) and the area under the plasma concentration-time curve from time 0 to the end of administration (AUC tau) of moricizine increased significantly by 88.9% and 121.1%, respectively. Oral clearance (Clo) decreased by 54%. The terminal half-life (t1/2) of moricizine was not affected, however (2.1 +/- 0.5 hours versus 2.4 +/- 0.7 hours). It is believed that these changes were due to the inhibition of hepatic metabolism by diltiazem, which resulted in an increased systemic availability of moricizine. Moricizine had opposite effects on the pharmacokinetics of diltiazem. Moricizine decreased the Cmax of diltiazem significantly (by 36%) and increased Clo by 52%. A small but statistically significant decrease in the t1/2 from 4.6 +/- 1.3 hours to 3.6 +/- 0.7 hours was observed. Despite this result, no remarkable changes (e.g., in Cmax, AUC, or t1/2) were found for the two major diltiazem metabolites desacetyl-diltiazem and N-desmethyl-diltiazem. It appears that the pharmacokinetic interaction of moricizine and diltiazem was metabolic. With the increase in moricizine concentrations and the decrease in diltiazem concentrations, adjustments in dose may be required to achieve optimal therapeutic response when coadministering both agents.

Dose-dependent pharmacokinetics of warfarin in healthy volunteers.

PURPOSE: To examine the pharmacokinetics of warfarin after administration of single oral doses (2, 5, and 10 mg) to healthy male volunteers. METHODS: A sensitive reverse-phase HPLC method was used to quantify warfarin plasma concentrations as low as 6 ng/ml. Blood samples were collected for up to 120 hours following administration of these doses. RESULTS: As the dose decreased from 5 to 2 mg, the apparent volume of distribution (V/F) increased from 12 to 21 liters and the terminal half-life (t1/2) increased from 47 to 71 hours. Oral clearance remained unchanged over the examined dose range. These apparent dose-dependent changes in warfarin's t1/2 and V/F may be due to saturable tissue binding of this drug. It appears that a previously undetected and prolonged terminal phase may exist but can not be adequately characterized with the 120-hour sampling interval. To evaluate this long t1/2, a follow-up study was conducted to examine warfarin's pharmacokinetics for up to 21 days following a 10-mg dose. The prolonged terminal phase started to become apparent when plasma levels declined to less than 100 ng/ml. The t1/2 of this terminal phase was determined to be approximately one week. CONCLUSIONS: This is the first report that documents the dose-dependent pharmacokinetics of warfarin and the previously unreported long t1/2 of one week for warfarin in humans.

Variability in the pharmacokinetics and pharmacodynamics of low dose aspirin in healthy male volunteers.

Data describing the pharmacokinetics and pharmacodynamics of low dose aspirin (acetylsalicylic acid; ASA) are limited. This single-center study was designed to determine the rate and extent of oral absorption of 80-mg ASA tablets in healthy, young male subjects and to assess the intra- and inter-subject variability of ASA pharmacokinetics and platelet aggregation effects. Ten subjects each received a single, open-label, oral 80-mg ASA dose on three separate days. Each dose was separated by a 2-week washout interval. Blood samples for pharmacokinetic determinations of ASA and its metabolite, salicylic acid (SA) and platelet aggregation studies were obtained at scheduled timepoints before and up to 24 hours after each dose. Peak plasma ASA levels of 1 microgram/mL were achieved within 30 minutes. Peak plasma SA levels of approximately 4 micrograms/mL were attained in 1 hour. The terminal half-lives (t1/2) of ASA and SA were 0.4 and 2.1 hours, respectively. Both ASA and SA pharmacokinetics and the platelet aggregation response to ASA exhibited considerable intra- and inter-subject variability. Inhibition of platelet aggregation was found to relate with ASA area under the plasma concentration versus time curve (AUC).

Enzyme induction by moricizine: time course and extent in healthy subjects.

Moricizine.HCl, a novel phenothiazine derivative with oral antiarrhythmic activity, was examined for its potential to induce its own hepatic metabolism and to alter the pharmacokinetics of the test substrate, antipyrine, in 12 healthy male subjects. Antipyrine oral clearance increased from a starting value of .74 mL/minute/kg to .98 (+32%, P < .01) after 7 days of moricizine administration (250 mg every 8 hours) and to 1.15 mL/minute/kg after 14 days (+47%, P < .05); t1/2 was correspondingly reduced. Moricizine oral clearance increased from a baseline of 3.01 L/hour/kg to 3.62 (+20%, P < .05) after 6 days of oral moricizine and 4.66 (+51%, not significant) after 13 days. Moricizine t1/2 was marginally, but consistently, increased (+23%, P < .05) instead of decreased as one would expect because of enzyme induction, presumably due to a decrease in systemic bioavailability and its influence on the oral volume of distribution. In half of the subjects who discontinued moricizine after 7 days, antipyrine pharmacokinetic values returned to near baseline 7 days later. Although moricizine was able to induce its own hepatic metabolism and that of antipyrine after 6 or 7 days of continuous administration, the electrocardiographic properties of moricizine did not appear to be altered by continuous dosing.

Effect of moricizine on the pharmacokinetics of single-dose theophylline in healthy subjects.

We studied the effect of multiple oral doses of moricizine on the pharmacokinetics of theophylline in healthy male subjects. Twelve subjects initially received two single oral doses of theophylline, one in the form of immediate-release Aminophyllin on day 1 and the other in the form of controlled-release Theo-Dur on day 3. Multiple oral doses of moricizine (Ethmozine, 250 mg every 8 h) began on day 5 and continued for 18 days. While receiving moricizine, the subjects were again given the two formulations of theophylline in the same order on days 19 and 21. Theophylline pharmacokinetic profiles were obtained over 36 h after all theophylline administrations. Multiple-dose moricizine administration significantly decreased (p < 0.0005) theophylline area under the curve by 32 and 36% after Aminophyllin and Theo-Dur, respectively. Theophylline t1/2 was also significantly decreased (p < 0.02) by concomitant moricizine dosing. Moricizine had no apparent effect on theophylline absorption after Aminophyllin, based on the lack of changes in the maximum plasma concentration (Cmax) and the time to reach Cmax; however, moricizine administration did decrease (p < 0.0005) the Cmax of theophylline after Theo-Dur. We conclude that these pharmacokinetic changes are most likely due to enzyme induction mediated by moricizine. Consequently, concomitant use of moricizine and theophylline may necessitate the administration of more frequent and higher doses of theophylline.

Effect of moricizine on the pharmacokinetics and pharmacodynamics of warfarin in healthy volunteers.

Moricizine HCl, a new orally active antiarrhythmic agent, induces its own hepatic metabolism and consequently may interfere with the metabolism of warfarin, a drug used commonly by cardiac patients that also is subject to extensive hepatic metabolism. Both drugs are also highly protein bound in plasma. To assess the possibility of an interaction, single-dose sodium warfarin (25 mg oral Coumadin, Du Pont Pharmaceuticals, Wilmington, DE) pharmacokinetics, pharmacodynamics; and plasma protein binding were examined in 12 healthy male volunteers 14 days before and 14 days after starting chronic oral moricizine HCl administration (250 mg every 8 hours). The terminal elimination rate constant of warfarin was increased by about 10% when measured in the presence of chronic moricizine administration. However, oral plasma clearance, apparent volume of distribution, maximum peak plasma concentration, time to reach peak concentration, and protein binding were unaffected. More importantly, there was no evidence of a pharmacodynamic interaction based on the prothrombin time profile. It was concluded that no clinically significant interaction occurs under these conditions.

Dose proportionality of moricizine after escalating multiple doses in healthy volunteers.

This study was designed to determine the dose linearity and proportionality of moricizine after multiple-dose administrations of 450 to 900 mg/day. The study design was an open-label, four-treatment, four-period sequentials escalating dose. Twelve subjects each received multiple doses of 150, 200, 250, and 300 mg of moricizine every 8 hours during 7 days of treatment. Blood samples for pharmacokinetic determinations were obtained on day 7 of each treatment period during an 8-hour time interval. Cmin determinations were also made on specific days of each treatment period. The AUC tau (area under the curve from time 0 to 8 hours), Cmax, and Cmin parameters were all normalized to the 250-mg (750 mg/day) dose. No statistically significant differences were seen in these parameters at the four treatment levels. It was concluded that moricizine follows first-order or linear pharmacokinetics after multiple dosing and exhibits dose proportional pharmacokinetics in the dosage-range studies. This range corresponds to the clinically useful dosage range.

Altered drug-serum protein binding in the genetically obese Zucker rat.

Drug-serum protein binding was evaluated in genetically obese Zucker rats, their lean littermates, and lean Sprague-Dawley rats. The free fraction (fp) of phenytoin was significantly higher in the obese rat (fp = 0.177) compared to its lean littermate (fp = 0.136), apparently due to displacement by free fatty acids. Conversely, diazepam and propranolol fp values were decreased in the obese Zucker rat (fp = 0.107 and fp = 0.122, respectively) compared to the lean Zucker rat (fp = 0.140 and fp = 0.174, respectively). Evidence strongly suggests that the increased binding of propranolol was not due to elevations in the serum concentrations of alpha1-acid glycoprotein (as is the case in the human obese population). Rather, the decreased fp for both diazepam and propranolol was a result of increased lipoprotein partitioning. Strain differences between the lean Zucker rat and lean Sprague-Dawley rat were also evident, with serum binding of the Sprague-Dawley rat more closely resembling the obese Zucker rat.

Serum protein binding and the role of increased alpha 1-acid glycoprotein in moderately obese male subjects.

Serum protein and lipid concentrations as well as the serum protein binding of propranolol, diazepam and phenytoin were measured in normal weight and obese volunteers. Concentrations of alpha 1-acid glycoprotein (AAG) in the obese subjects were double that of the lean controls. Conversely, concentrations of high density lipoproteins (HDL) were decreased in the obese group. The serum binding of propranolol was increased in the obese subjects and correlated with serum AAG concentrations. Diazepam binding was slightly decreased in the obese as a result of lower serum albumin concentrations and elevated free fatty acids. The binding of phenytoin was comparable in all of the volunteers. These findings point out some of the complex pathophysiologic changes associated with obesity which may in turn influence drug disposition and hence drug therapy in the obese patient.

Physiological model for distribution of sulfathiazole in swine.

A physiological flow model was developed for the distribution of sulfathiazole residues in various tissues in swine. The approach was compartmental, in which the compartments and equilibrium constants had physiological meaning. Differential equations were developed, and appropriate parameter values and initial conditions were substituted and solved by a fourth-order Runga-Kutta technique. Simulation values corresponded with the experimentally determined concentration values in plasma and kidney, liver, muscle, fat, and heart tissues.