The use of microsensors to study the role of the loading rate and surface velocity on the growth and the composition of nitrifying biofilms.

The good composition and activity of biofilms are very important for successful operation and control of fixed-film biological reactors employed in liquid effluents treatment. During the last decade, microsensors have been applied to study microbial ecology. These sensors could provide information regarding the microbial activity concerning nitrification and denitrification that occur inside biofilms. Other techniques of molecular biology, such as fluorescence in situ hybridization (FISH), have also contributed to this matter because their application aids in the identification of the bacterial populations that compose the biofilms. The focus of this paper was to study the loading rate and surface velocity to promote the development of nitrifying biofilms in three distinct flow cells that were employed in the post treatment of a synthetic wastewater simulating the effluent from a UASB (Upflow Anaerobic Sludge Blanket) reactor. Using the FISH technique, it was found that the population of ammonia-oxidizing-bacteria was greater than that of nitrite-oxidizing-bacteria; this was also supported by the lower production of nitrate determined by physicochemical and microsensor analyses. It was verified that the loading rate and surface velocity that promoted the greatest nitrogen removal were 0.25 g N-amon m(-2)biofilm day(-1) and 1 m h(-1), respectively.

Single-dose randomized, open-label, 2-way crossover bioequivalence study of clopidogrel 75 mg tablet in healthy volunteers under fasting conditions.

AIM: This study aimed to assess the bioequivalence of 2 formulations of 75 mg clopidogrel hydrogen sulphate film-coated tablet, under fasting conditions. SUBJECTS AND METHODS: 64 healthy subjects, age ranging from 19 to 55 years, were enrolled in a single-centre, randomized, single-dose, open-label, 2-way crossover study, with a minimum washout period of 7 days. Plasma samples were collected up to 24 h post dosing. Clopidogrel and clopidogrel carboxylic acid levels were determined by reverse-phase high-performance chromatography coupled to tandem mass spectrometry detection, LC-MS-MS method. Pharmacokinetic parameters used for bioequivalence assessment were the AUClast (area under the concentration-time curve from time zero to time of last observed nonzero concentration) and the Cmax (maximum observed concentration). These parameters were determined from the clopidogrel concentration data using non-compartmental analysis as well for clopidogrel carboxylic acid concentration data. RESULTS: The 90% CI (90% confidence intervals), obtained by analysis of variance (ANOVA) were within the predefined ranges (80.00 - 125.00%) for both analytes. CONCLUSION: Bioequivalence between test and formulations, under fasting conditions, was concluded both in terms of rate and extent of absorption.

Comparative bioavailability of two formulations of sibutramine.

This study was conducted in order to compare the bioavailability of two capsule formulations containing 15 mg of sibutramine, N-{1-[1-(4-chlorophenyl)cyclobutyl]-3-methylbutyl}-N,N-dimethylamine hydrochloride monohydrate, 84485-00-7 CAS registry number. 62 healthy subjects were enrolled in a single-center, randomized, single-dose, open-label, 2-way crossover study, with a minimum washout period of 14 days. Plasma samples were collected up to 72.0 hours post-dosing. R-sibutramine, S-sibutramine, N-mono-desmethyl-sibutramine (M1) and N-di-desmethyl-sibutramine (M2) levels were determined by reverse liquid chromatography and detected by tandem mass spectrometry detection, LC/MS/MS method. Pharmacokinetic parameters used for bioequivalence assessment were the area under the concentration-time curve from time zero to time of last non-zero concentration (AUC0-t) and the maximum observed concentration (Cmax). These parameters were determined from sibutramine enantiomers as well from M1 and M2 concentration data using non-compartmental analysis. The 90% confidence intervals obtained by analysis of variance were 89.25 - 122.88% for Cmax, 90.37 - 123.18% for AUC0-t and 91.20 - 122.38% for AUCinf for R-sibutramine and 88.27 - 124.08% for Cmax, 86.15 - 121.78% for AUC0-t and 88.02 - 120.96% for AUCinf for S-sibutramine. These results were all within the range of 80.00 - 125.00% established by regulatory requirements. Bioequivalence between formulations was concluded both in terms of rate and extent of absorption.

Bioequivalence of two formulations of levetiracetam.

This study was conducted in order to compare the bioavailability of two tablet formulations containing 1,000 mg levetiracetam, (S)-a-ethyl-2-oxo-1-pyrrolidine acetamide, 102767-28-2 CAS registry number. 18 healthy subjects were enrolled in a single-center, randomized, single-dose, open-label, 2-way crossover study, with a minimum washout period of 7 days. Plasma samples were collected up to 36.0 hours post-dosing. Levetiracetam levels were determined by reverse liquid chromatography and detected by tandem mass spectrometry detection, LC-MS/MS method. Pharmacokinetic parameters used for bioequivalence assessment, area under the concentration-time curve from time 0 to time of last non-zero concentration (AUClast) and from time zero to infinitive (AUCinf) and maximum observed concentration (Cmax), were determined from the levetiracetam concentration data using non-compartmental analysis. The 90% confidence intervals obtained by analysis of variance were 88.98 - 108.75% for Cmax, 99.90 - 104.81% for AUClast and 100.11 - 105.23 %for AUCinf this is, within the predefined ranges. Bioequivalence between formulations was concluded both in terms of rate and extent of absorption.

Thrombin generation and activity during thrombolysis and concomitant heparin therapy in patients with acute myocardial infarction.

OBJECTIVES: This prospective study investigated the behavior of thrombin generation and activity during thrombolysis and concomitant heparin administration. BACKGROUND: It has been shown that during thrombolytic therapy there is an increase in thrombin generation and activity. Increased thrombin activity is suppressed by concomitant intravenous heparin, but it is unknown whether thrombin generation is also affected. METHODS: Thrombin generation was assessed by measuring prothrombin fragment 1 + 2 and thrombin-antithrombin complex plasma levels and thrombin activity by measuring fibrinopeptide A plasma levels. Serial blood samples were obtained before and at 90 min and 24 and 48 h after the administration of streptokinase (15 patients), recombinant tissue-type plasminogen activator (15 patients) or anistreplase (13 patients). An intravenous bolus of heparin (5,000 IU) was administered before the start of thrombolytic therapy, followed by an infusion of 1,000 U/h to maintain an activated partial thromboplastin time > 1.5 times baseline. RESULTS: During thrombolytic and concomitant heparin therapy, there was an increase in the plasma levels of prothrombin fragment 1 + 2 (baseline 1.08 vs. 2.73 nmol/liter, p < 0.001) and thrombin-antithrombin complex (baseline 6.5 vs. 17.1 micrograms/ml, p < 0.01) at 90 min, whereas no change was observed in fibrinopeptide A at 90 min (baseline 2.8 vs. 3.0 nmol/liter, p = NS). CONCLUSIONS: During thrombolytic therapy with both fibrin-specific and non-fibrin-specific drugs, there is an increase in thrombin generation despite concomitant administration of intravenous heparin.

Non neutralizing antibodies to tissue type plasminogen activator in the serum of acute myocardial infarction patients treated with the recombinant protein.

Recombinant tissue-type plasminogen activator (rt PA) is currently used as a thrombolytic agent in the management of acute myocardial infarction (AMI). Since it is known that other recombinant proteins induce antibody formation when administered to humans, we determined the presence of anti-rt-PA antibodies in serial blood samples from 60 AMI patients (43 treated with and 17 without rt-PA). Blood samples were taken upon hospital admission, 15 days and 1, 3, 6 months thereafter. A blood sample was also collected from 200 healthy subjects. Using an ELISA, anti-rt-PA antibodies were detected as serum immunoglobulins specifically binding immobilized rt-PA, AMI patients before treatment and normal subjects exhibited negligible levels of anti-rt-PA antibodies; both groups had only one outlier value. Fifteen days after rt-PA treatment, 2 AMI patients showed an increase in antibody titer beyond the highest normal value. This titer progressively decreased during the following 6 months. The antibodies from these two patients bound rt-PA both in a solid and fluid phase. They bound melanoma t-PA to a lower degree and did not bind urokinase type plasminogen activator at all, indicating specificity for t-PA. The marked temporal relationship between rt-PA infusion and antibody appearance indicated that antibody formation had been elicited by the infusion of rt-PA. Nevertheless, the lack of anti-rt-PA antibody interference with rt-PA function in vitro, along with the favourable clinical outcome of those patients having such antibodies would indicate that the appearance of anti-rt-PA antibodies does not interfere with the physiological fibrinolytic activity.

C-reactive protein elevation and early outcome in patients with unstable angina pectoris.

C-reactive protein, a reactant of the acute phase of inflammation, has been shown to be increased in patients with unstable angina. Moreover, it has recently been found that increased C-reactive protein is associated with a poor outcome during hospitalization in selected patients with severe unstable angina. The aim of this study was to investigate the prognostic value of C-reactive protein elevation in a large population with unstable angina. We measured serum levels of this marker in 140 patients hospitalized with unstable angina (class IIIB of the Braunwald classification, mean time from last anginal episode 5 +/- 5 hours). Thirty-nine of them (28%) had increased serum levels on hospital admission and 33 (24%) experienced an adverse outcome (myocardial infarction or refractory angina) during hospitalization. Kaplan-Meier analysis showed that the probability of developing cardiac events during hospitalization was not different between patients with and without abnormal C-reactive protein levels. Furthermore, the incidence of ischemia at Holter monitoring during the first 72 hours after hospitalization was not different between patients with and without abnormal C-reactive protein. In a representative population of patients with unstable angina, a sizable proportion had increased serum C-reactive protein levels; however, abnormal concentrations of C-reactive protein do not predict an adverse outcome in the early phase after the acute episode.

Activation of the hemostatic system during thrombolytic therapy.

Activation of the hemostatic mechanism has been described during thrombolytic therapy. This phenomenon has been detected by new methods of assessing hemostatic system function, based on immunoenzymatic or radioimmunoassays. However, these methods are extremely sensitive and, unless they are performed in expert laboratories, carefully following the recommended procedures, they generate in vitro artifacts. A description of these methods is provided, as well as a critical review of the available studies. The correct use of these methods will provide us with an understanding of the complex response of the hemostatic system to pharmacologic thrombolysis.

Lead poisoning and hookworm infection as multiple factors in anaemia.

A retrospective study was carried out in a rural area of north-eastern Brazil, to search for interactions between biological and chemical agents present in the environment as causes of anaemia. A lead smelter situated in a hookworm endemic area provided the opportunity to look at the effect of this double exposure in relation to laboratory defined anaemia, by comparing the odds ratios in different subgroups of 109 "cases" and 107 "controls". The subgroup with both hookworm infection and chronic lead poisoning--measured by the concentration of delta-ALA excreted in urine--had an odds ratio of developing anaemia five times greater than individuals with neither. Although a synergistic effect could not be demonstrated, the additive effect of the two conditions placed this group in a higher risk category.

Prolonged streptokinase infusion in patients with unstable angina: results of a randomized, placebo-controlled clinical trial.

BACKGROUND: The purpose of this study was to assess the efficacy both of prolonged (48 h) and of short-duration (1 h) administrations of streptokinase in patients with unstable angina. In unstable angina, thrombosis is a dynamic process that waxes and wanes for hours and even days. The majority of previous studies have investigated the efficacy of short-duration thrombolytic regimens. METHODS: One hundred patients with acute unstable angina were randomly allocated to receive placebo, 1,500,000 U streptokinase during 1 h or 250,000 U streptokinase during 1 h and then a prolonged infusion of 100,000 U for the next 48 h. All of the treatments included intravenous heparin administration for 72 h. RESULTS: No death occurred in the study population. One of 34 patients treated with placebo (2.9%), three of 33 treated with streptokinase during 1 h (9.0%) and three of 33 treated with streptokinase during 48 h (9.0%) had a myocardial infarction. Refractory angina occurred in nine, three and seven patients receiving placebo, streptokinase during 1 h and streptokinase during 48 h, respectively. Kaplan-Meier analysis showed that the total probability for a patient to be free of cumulative events did not differ among the three groups of patients (NS). Fourteen patients (41%) receiving placebo, 15 patients (45%) receiving streptokinase during 1 h and 14 patients (42%) receiving streptokinase during 48 h had ischaemic episodes detected by Holter monitoring during the first 72 h after hospital admission (NS). Two patients receiving streptokinase during 48 h required blood transfusion, and a greater incidence of minor bleeding (P < 0.05) and adverse events (P < 0.02) was observed in patients receiving prolonged streptokinase administration than in those receiving streptokinase during 1 h or placebo. CONCLUSIONS: In patients with acute unstable angina, the administration of two different regimens of streptokinase significantly reduces the probability neither of developing cardiac events during hospitalization nor of ischaemia detected by Holter monitoring in the early phase after hospital admission. Although the sample size of the study provided sufficient power to exclude only a large difference in effect size, it did allow us to detect a significantly higher incidence of bleeding in the group of patients treated with prolonged streptokinase infusion.

Nasal provocation and immunotherapy.

Nasal mucosa is heavily exposed to inflammatory and allergic stimuli, rhinitis being the most common form of allergic respiratory disease. The nose is an easily accessible organ and a good model for the study of allergies as it makes it possible to monitor the effects of specific challenges as well as therapeutic interventions, namely specific immunotherapy (SIT). Injectable, nasal or sublingual SIT are useful therapeutic strategies in the management of allergic rhinitis patients. Monitoring the evolution of parameters such as clinical scores, nasal peak flow variation or drug requirements during SIT provides important information on its clinical efficacy. Laboratory measurement of tryptase and eosinophil cationic protein in the target organ after specific nasal provocation makes it possible to record changes in the release of mast cell and eosinophil mediators, thus providing objective evidence of the immunological efficacy of this therapy on these cell populations and providing data which eventually will contribute to a better understanding of the multiple mechanisms of action of allergen desensitization therapy.

Effects of buflomedil in a group of patients with chronic peripheral arterial diseases. Clinical and hemorheological evaluation.

Fifty-three patients suffering from chronic arterial diseases of the lower limbs were treated with buflomedil, a vasoactive drug with vasodilating and hemorheological action on the microcirculation. The patients suffered from pain on walking or pain at rest; they were given 300 mg buflomedil orally twice a day for a period of about 2 months. The walking distance before pain onset was checked in all patients before and after the trial. Blood and plasma viscosity, haematocrit and fibrinogen and a Doppler velocimetry were also recorded. A significant improvement of the walking distance before pain onset was observed in nearly all patients, and in most patients the morphology of the velocity waves improved, too. No clear correlation between the positive clinical results and the hemorheological parameters studied could be observed.

Drug compliance and the elderly: who is publishing, where, and when?

Population aging has occurred in a rather heterogeneous way worldwide. The increasing size of the elder age group highlights various health-related problems for the elderly. One such issue is non-compliance with drug prescriptions, a potential source of serious, even life-threatening problems for the patient. The authors have proposed to identify and rank countries that develop research on drug compliance among the elderly, relevant periodicals, and the frequency articles were published between January 1987 and December 1997. A descriptive study was carried out on the basis of a bibliographical review. Three databases were surveyed: MEDLINE, SOCIOFILE and LILACS. The sample included 440 articles, limited to the behavioral sphere. The number of periodicals recorded was 255, varying from one to tem articles. The number of articles published during the study period varied from 23 in 1987 to 49 in 1992, dropping to 29 in 1997. Frequency of the number of articles/year was erratic up to 1992, leveling off from 1993 on at more than double the baseline figure. The authors emphasize the need for developing multi-focused research worldwide.

Nasal allergen challenge and immunotherapy control.

Nasal allergen challenges, despite not reproducing exactly natural allergen exposure, are a very useful method to understand the complex cellular kinetics and cellular interactions that occur in allergic rhinitis. Cell-specific soluble mediator measurements can give useful diagnosis information as well as complementary information regarding the monitoring of specific immunotherapy. In this article we present data concerning eosinophil cationic protein and tryptase measurements after nasal allergen and the influence of specific immunotherapy on nasal peak flow before and 1, 2 and 3 years after starting immunotherapy.

Development of immunoglobulins to venoms during specific immunotherapy.

Immunotherapy against venoms (itv) is an efficacious treatment for most subjects who are allergic to hymnenoptera venoms. The authors studied 8 patients: 7 who were allergic to honey been venom and 1 who was allergic to wasp venom, followed for two years during immunotherapy with an aqueous extract of pure venoms from ALBAY Dome Hollister Stier. Specific IgE and IgG4 were evaluated by the Elisa Cap Technique of Pharmacia at different times: T0 before immunotherapy, T1 (one year after) and T2 (2 years after). A significant fall of specific IgE (p < 0.02) and a significant increase in specific IgG4 (p < 0.008) were seen during the two years in all patients. Four of the patients were re-stung and none had systemic reactions. These results suggest that increase in specific IgG4 is correlated with the protective effect of immunotherapy.

Remodeling of white adipose tissue metabolism by physical training prevents insulin resistance.

AIM: This study sought to determine the role of white adipose tissue (WAT) metabolism in the prevention of insulin resistance (IR) by physical training (PT). MAIN METHODS: Male C57BL/6J mice were assigned into groups CHOW-SED (chow diet, sedentary; n=15), CHOW-TR (chow diet, trained; n=18), CAF-SED (cafeteria diet, sedentary; n=15) and CAF-TR (cafeteria diet, trained; n=18). PT consisted of running sessions of 60 min at 60% of maximal speed conducted five days per week for eight weeks. KEY FINDINGS: PT prevented body weight and fat mass accretion in trained groups and prevented hyperglycemia, hyperinsulinemia, glucose intolerance and IR in the CAF-TR. The CAF-SED group presented higher leptin and free fatty acid and lower adiponectin serum levels compared with other groups. Lipolytic activity (in mmol/10(6) adipose cells) stimulated by isoproterenol increased in CHOW-TR (16347±3005), CAF-SED (18110±3788) and CAF-TR (15837±2845) compared with CHOW-SED (8377±2284). The CAF-SED group reduced FAS activity compared with CHOW-SED and CHOW-TR, reduced citrate synthase activity and increased DGAT2 content compared with other groups. Both trained groups reduced G6PDH activity and increased the expression of p-AMPK (Thr172) compared with sedentary groups. CAF-SED group had lower levels of AMPK, p-AMPK (Thr172), ACC and p-ACC (Ser79) compared with other groups. SIGNIFICANCE: The prevention of IR by PT is mediated by adaptations in WAT metabolism by improving lipolysis, preventing an increase in enzymes responsible for fatty acid esterification and by activating enzymes that improve fat oxidation instead of fat storage.