Biomedical subjects

G de Nucci

Publications and source records attributed to G de Nucci.

At least 19 recordsLinked to original sources

PubMed2005

Purification and initial characterization of a novel protein with factor Xa activity from Lonomia obliqua caterpillar spicules.

A novel protein with factor Xa-like activity was isolated from Lonomia obliqua caterpillar spicules by gel filtration chromatography and reversed-phase high-performance liquid chromatography. The protein had a mass of 20745.7 Da, as determined by mass spectrometry, and contained four Cys residues. Enzymatic hydrolysis followed by de novo sequencing by tandem mass spectrometry was used to determine the primary structure of the protein and the cysteine residues linked by disulfide bridges. The positions of 24 sequenced tryptic peptides, including the N-terminal, were deduced by comparison with a homologous protein from the superfamily Bombycoidea. Approximately 90% of the primary structure of the active protein was determined.

Alkylation↗

PubMed2004

Analysis of five streptokinase formulations using the euglobulin lysis test and the plasminogen activation assay.

Streptokinase, a 47-kDa protein isolated and secreted by most group A, C and G ss-hemolytic streptococci, interacts with and activates human protein plasminogen to form an active complex capable of converting other plasminogen molecules to plasmin. Our objective was to compare five streptokinase formulations commercially available in Brazil in terms of their activity in the in vitro tests of euglobulin clot formation and of the hydrolysis of the plasmin-specific substrate S-2251. Euglobulin lysis time was determined using a 96-well microtiter plate. Initially, human thrombin (10 IU/ml) and streptokinase were placed in individual wells, clot formation was initiated by the addition of plasma euglobulin, and turbidity was measured at 340 nm every 30 s. In the second assay, plasminogen activation was measured using the plasmin-specific substrate S-2251. Streptase was used as the reference formulation because it presented the strongest fibrinolytic activity in the euglobulin lysis test. The Unitinase and Solustrep formulations were the weakest, showing about 50% activity compared to the reference formulation. All streptokinases tested activated plasminogen but significant differences were observed. In terms of total S-2251 activity per vial, Streptase (75.7 +/- 5.0 units) and Streptonase (94.7 +/- 4.6 units) had the highest activity, while Unitinase (31.0 +/- 2.4 units) and Strek (32.9 +/- 3.3 units) had the weakest activity. Solustrep (53.3 +/- 2.7 units) presented intermediate activity. The variations among the different formulations for both euglobulin lysis test and chromogenic substrate hydrolysis correlated with the SDS-PAGE densitometric results for the amount of 47-kDa protein. These data show that the commercially available clinical streptokinase formulations vary significantly in their in vitro activity. Whether these differences have clinical implications needs to be investigated.

Blood Coagulation Tests↗

PubMed2002

Loss and sprouting of nitric oxide synthase neurons in the human epileptic hippocampus.

PURPOSE: Nitric oxide (NO) has been implicated in a variety of functions, including the control of synaptic plasticity and sensory signaling. Current evidence suggests that this unconventional neurotransmitter mediates N-methyl-d-aspartate (NMDA) receptor-linked excitotoxicity. This study describes the expression of neuronal NO synthase (nNOS) immunoreactivity (IR) in hippocampi from patients with temporal lobe epilepsy (TLE). METHODS: Hippocampi from patients with clinical symptoms, neuroimaging, and EEG typical of hippocampal sclerosis (HS; n = 22) were compared with those from patients with neocortical temporal lesions (NONHS; n = 4) and autopsy (AUT; n = 18) patients for total cells, and nNOS-IR neuron and puncta densities. RESULTS: Compared with AUT, HS hippocampi had significantly less nNOS-IR neuron densities in the fascia dentata (FD); hilus, and CA4, CA3, CA2, and CA1 subfields. HS hippocampi had significantly greater nNOS-IR puncta densities in the FD, as compared with AUT and NONHS. CONCLUSIONS: Our results show that hippocampi from TLE patients exhibit a loss of nNOS-IR neurons and an abnormal FD innervation. The release of NO can influence the dynamics of ionic channels and neurotransmitter release, thus affecting neuronal membrane potential. Because the NOergic transmission does not obey the topographic constraints imposed on conventional transmitters, target cells can be stimulated even in regions with severe deafferentation. The plastic changes described here may contribute to abnormal hippocampal excitability.

Epilepsy, Temporal Lobe↗

PubMed2001

Cyclooxygenase selectivity of non-steroid anti-inflammatory drugs in humans: ex vivo evaluation.

We have recently described a novel assay to assess ex vivo the activity and selectivity on cyclooxygenase-1 and -2 (EC 1.14.99.1) of non-steroid anti-inflammatory drugs (NSAID) administered to rats [Br. J. Pharmacol. 126 (1999) 1824.]. Here, we have extended these studies to humans. Healthy male volunteers were given orally one of the following drugs (mg) for 5 days: etodolac (200 or 400 b.i.d.), meloxicam (7.5 or 15 q.d.), nimesulide (100 or 200 b.i.d.), nabumetone (500 or 1000 b.i.d.) or naproxen (500 b.i.d.). Blood samples were withdrawn from the volunteers before and up to 24 h after the last dose. Plasma obtained from the blood was tested for its ability to inhibit prostanoid formation in interleukin-1beta-treated A549 cells (cyclooxygenase-2 system) and human washed platelets (cyclooxygenase-1 system). Plasma from etodolac-treated subjects demonstrated a slight selectivity towards the inhibition of cyclooxygenase-2. This effect was more prominent in plasma from subjects receiving meloxicam or nimesulide. Plasma from nabumetone-treated subjects showed no or little selectivity towards cyclooxygenase-1 depending on the dose of drug administered, while plasma taken from subjects receiving naproxen was more active at inhibiting cyclooxygenase-1 than cyclooxygenase-2. In conclusion, we have demonstrated that this assay can be used to assess ex vivo the relative activity against cyclooxygenase-1 and cyclooxygenase-2 of NSAIDs consumed by human volunteers. It is to be hoped that data from such systems will aid in our understanding of the relationships between the differential inhibition of cyclooxygenase-1 and cyclooxygenase-2 by NSAIDs and their reported efficacies and (gastrointestinal) toxicities.

Adolescent↗

PubMed2001

Determination of minocycline in human plasma by high-performance liquid chromatography coupled to tandem mass spectrometry: application to bioequivalence study.

Minocycline was determined in human plasma by HPLC-MS-MS using clarithromycin as an internal standard. The method is fast (single liquid extraction and run time of <3 min) and sensitive (5 ng/ml) and it was employed in a bioequivalence study of two 100 mg tablet formulations in 24 healthy volunteers. The 90% confidence interval of the individual ratio geometric mean for both AUC(0-96 h) and Cmax were 99.2-111.1% and 95.6-117.5%, respectively. Thus, Minoderm was considered bioequivalent to Minomax according to both the rate and extent of absorption. No food interaction was observed with either formulation.

Administration, Oral↗

PubMed2001

Nitric oxide may underlie learned fear in the elevated T-maze.

The present study evaluated the role of nitric oxide (NO) in learned and innate fear in rats submitted to the elevated T-maze (ETM). Learned and innate fear were evaluated through the inhibitory avoidance and escape behaviour from the open arms, respectively. Rats treated with the inhibitor of NO synthesis N(omega)-nitro-L-Arginine methyl ester (L-NAME; 5, 10, and 50 mg. kg(-1)) were able to learn the inhibitory avoidance. However, L-NAME (50 mg. kg(-1)), but not its inert isomer N(omega)-nitro-D-arginine methyl ester (D-NAME, 50 mg. kg(-1)), impaired the inhibitory avoidance 2 with no change in the baseline values, thus suggesting an anxiolytic-like effect without locomotor impairment. All treatments with L-NAME were able to induce increased mean arterial pressure (MAP), measured indirectly through the animal's tail. The treatment with L-NAME (5 and 10 mg. kg(-1)) failed to induce anxiolysis but significantly increased the MAP of the animals, which indicates that hypertension per se, did not underlie anxiolysis induced by L-NAME. L-Arginine, the precursor molecule for NO synthesis, facilitated the inhibitory avoidance and counteracted the L-NAME (50 mg. kg(-1))-induced anxiolysis. Neither previous treatment was able to change the escape behaviour. The results indicate that NO may underlie learned, but not innate, fear in the ETM.

Animals↗

PubMed2001

Gabapentin quantification in human plasma by high-performance liquid chromatography coupled to electrospray tandem mass spectrometry. Application to bioequivalence study.

A rapid, sensitive and specific analytical method was developed and validated to quantify gabapentin in human plasma using acetaminophen as an internal standard. The method employs a single plasma protein precipitation. The analytes are chromatographed on a C4 reversed-phase chromatographic column and analyzed by mass spectrometry in the multiple reaction monitoring (MRM) mode. The method has a chromatographic run time of 4 min and a linear calibration curve over the range 50-10 000 ng x ml(-1) (r > 0.999). The between-run precision, based on the relative standard deviation for replicate quality controls, was < or = 4.8 % (200 ng x ml(-1)), 6.0% (1000 ng x ml(-1)) and 4.4% (5000 ng x ml(-1)). The between-run accuracy was +/-2.6, 4.4 and 0.5% for the above-mentioned concentrations, respectively. This method was employed in a bioequivalence study of two gabentin capsule formulations (Progresse from Biosintética, Brazil, as a test formulation, and Neurotin from Parke-Davis, as a reference formulation) in 24 healthy volunteers of both sexes who received a single 300 mg dose of each formulation. The study was conducted using an open, randomized, two-period crossover design with a 7-day washout interval. The 90% confidence interval (CI) of the individual ratio geometric mean for Progresse/Neurotin was 87.9-115.6% for AUC(0-36 h) and 88.6-111.7% for Cmax. Since both 90% CI for AUC(0-36 h) and Cmax were included in the 80-125% interval proposed by the US Food and Drug Administration, Progresse was considered bioequivalent to Neurotin according to both the rate and extent of absorption.

Acetates↗

PubMed2001

Determination of RSD921 in human plasma by high-performance liquid chromatography-tandem mass spectrometry using tri-deuterated RSD921 as internal standard: application to a phase I clinical trial.

A fast, sensitive and specific method is presented for the quantification of RSD921 in human plasma by liquid chromatography coupled with tandem mass spectrometry using tri-deuterated RSD921 (3d-RSD921) as an internal standard. A single-step liquid/liquid extraction was performed with diethyl ether/hexane (80 : 20, v/v) using 0.5 ml of plasma. The plasma calibration curves were linear from 0.1 to 20 ng ml(-1) (r > 0.999). Between-run precision, based on the percent relative deviation for replicate (n = 40) quality controls, was < or =7.27% (0.5 ng ml(-1)), < or =7.39% (5.0 ng ml(-1)), and < or =5.06% (20.0 ng ml(-1)). Between-run accuracies, based on the relative error, were +/-2.59%, +/-1.23% and +/-1.64% respectively. The method was developed to evaluate the pharmacokinetic profile after 15 min of intravenous stepwise-ascending infusion dose of RSD921 in 18 healthy volunteers. A dissociation study of protonated RSD921 and 3d-RSD921 by collision-induced dissociation using in-source fragmentation and tandem mass spectrometry is also presented.

Anesthetics, Local↗

PubMed2001

Synthesis of substituted benzamides as anti-inflammatory agents that inhibit preferentially cyclooxygenase 1 but do not cause gastric damage.

Parsalmide (5-amino-N-butyl-2-(2-propynyloxy) benzamide) (5a), is a non-steroidal anti-inflammatory drug (NSAID), commercialised in Italy until 1985 with the brand name of Synovial(R), that has been widely used to treat arthritic patient. In addition, it was shown to spare gastric mucosa. Here we have synthesised a series of novel substituted benzamides, related to Parsalmide, and have evaluated their activity in vitro on COX-1 and COX-2 as well as in vivo in the carrageenin-induced rat paw edema, a classical in vivo anti-inflammatory assay. Compounds 5b, 11a and 11b, which showed a favourable profile in vitro and in vivo, were screened in comparison with Parsalmide for gastrointestinal (GI) tolerability in vivo in the rat. Results obtained showed that Parsalmide and compound 11b inhibited both COX-1 and COX-2 in vitro as well as they were active in vivo. Both compounds were devoid of gastric effect at the efficacious dose. In addition, both prevented indomethacin-induced gastric damage. Thus, these compounds may guide the definition of a new leading structure with anti-inflammatory activity that may allow designing new safer NSAIDs.

Animals↗

PubMed2001

The plasma protein extravasation induced by adenosine and its analogues in the rat dorsal skin: evidence for the involvement of capsaicin sensitive primary afferent neurones and mast cells.

1. The contribution of sensory neurons and mast cells to the oedema evoked by adenosine A1 (N(6)-cyclopentyladenosine, CPA, 3 - 30 nmol site(-1)), A2 (5'N-ethylcarboxamidoadenosine, NECA, 1 - 10 nmol site(-1)) and A3 receptor agonists (N6-[3-iodobenzyl]-N-methyl-5'-carboxiamidoadenosine, IB-MECA, 0.01 - 3 nmol site(-1)) was investigated in the rat skin microvasculature, by the extravascular accumulation of intravenously-injected (i.v.) 125I-albumin. 2. Intradermal (i.d.) injection of adenosine and analogues induced increased microvascular permeability in a dose-dependent manner (IB-MECA > NECA > CPA > adenosine). The non-selective adenosine receptor antagonist theophylline (5 - 50 nmol site(-1)) markedly inhibited adenosine, CPA or NECA but not IB-MECA-induced plasma extravasation. The A1 receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 0.3 - 3 micromol kg(-1), i.v.) significantly reduced CPA-induced plasma extravasation whereas responses to adenosine, NECA or IB-MECA were unchanged. The A2 receptor antagonist 3,7-dymethyl-1-proprargylxanthine (DMPX, 0.5 - 50 nmol site(-1)) significantly reduced NECA-induced plasma extravasation without affecting responses to adenosine, CPA and IB-MECA. 3. The tachykinin NK1 receptor antagonist (S)-1-[2-[3-(3,4-dichlorphenyl)-1 (3-isopropoxyphenylacetyl) piperidin-3-yl] ethyl]-4-phenyl-1 azaniabicyclo [2.2.2]octane chloride (SR140333), but not the NK2 receptor antagonist (S)-N-methyl-N[4-acetylamino-4-phenyl piperidino)-2-(3,4-dichlorophenyl)butyl]-benzamide (SR48968), significantly inhibited the plasma extravasation evoked by higher doses of adenosine (100 nmol site(-1)), CPA (100 nmol site(-1)), NECA (1 nmol site(-1)) and IB-MECA (0.1 - 1 nmol site(-1)). In rats treated with capsaicin to destroy sensory neurons, the response to higher doses of adenosine, CPA and NECA, but not IB-MECA, was significantly inhibited. 4. The effects of adenosine and analogues were largely inhibited by histamine and 5-hydroxytryptamine (5-HT) antagonists and by compound 48/80 pretreatment. 5. In conclusion, our results provide evidence that adenosine A1 and A2, but not A3, receptor agonists may function as cutaneous neurogenic pro-inflammatory mediators; acting via microvascular permeability-increasing mechanisms that can, depending on dose of agonist and purine receptor under study, involve the tachykinin NK1 receptor and mast cell amines.

Adenosine↗

PubMed2001

Nitric oxide regulates human eosinophil adhesion mechanisms in vitro by changing integrin expression and activity on the eosinophil cell surface.

1. The nitric oxide synthase (NOS) inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME), inhibits both rat and human eosinophil chemotaxis in vitro. Here, the role of nitric oxide (NO) in human eosinophil cell surface integrin expression and function was investigated. 2. Human peripheral blood eosinophils were treated with L-NAME (0.01 - 1.0 mM) and their adhesion to human fibronectin and serum observed. Adhesion of cells to fibronectin and serum increased by 24.0+/-4.6 and 43.8+/-4.7%, respectively, when eosinophils were treated with 1.0 mM L-NAME. Increased adhesion by L-NAME could be abolished when cells were co-incubated with VLA-4- and Mac-1-specific monoclonal antibodies (mAbs). 3. The NO donor, sodium nitroprusside (2.5 mM), significantly inhibited eosinophil adhesion to fibronectin and serum by 34.3+/-4.5 and 45.2+/-5.6%, respectively. This inhibition was accompanied by a 4 fold increase in the levels of intracellular cyclic GMP. 4. Flow cytometrical analysis demonstrated that L-NAME induced an increased expression of CD11b (Mac-1) on the eosinophil cell surface of 36.3+/-7.4%. L-NAME had no effect upon CD49d (VLA-4) expression. 5. Treatment of human eosinophils, in vitro, with H-[1,2,4] oxadiazolo quinoxalin-1-one (ODQ) (0.1 mM), an inhibitor of soluble guanylate cyclase, also significantly increased eosinophil adhesion to fibronectin and serum by 73.5+/-17.9 and 91.7+/-12.9%, respectively. This increase in adhesion could also be inhibited by co-incubation with the Mac-1 and VLA-4-specific mAbs. 6. In conclusion, results indicate that NO, via a cyclic GMP-dependent mechanism, inhibits the adhesion of human eosinophils to the extracellular matrix (ECM). This inhibition is accompanied by a decrease in the expression and function of the eosinophil's adhesion molecules, in particular, the expression of the Mac-1 integrin and the function of the VLA-4 integrin.

Cell Adhesion↗

PubMed2001

Expression of nitric oxide synthase isoforms and nitrotyrosine immunoreactivity by B-cell non-Hodgkin's lymphomas and multiple myeloma.

AIMS: Nitric oxide synthases (NOS) are isoenzymes that catalyse the synthesis of nitric oxide (NO). The three main NOS isoforms are: NOS1 or neuronal, NOS2 or inducible, and NOS3 or endothelial. NO plays both physiological and pathological roles, depending on its rate of synthesis and concentration, cellular source and microenvironment. Apoptosis is an important biological factor in low-grade lymphomas, and NO is able to prevent apoptosis. In-situ expression of NOS and synthesis of NO have been shown in several malignant tumours, but not in lymphoid neoplasms. This study evaluates whether human B-cell neoplasms express NOS isoforms, and nitrotyrosine (NY), which is usually interpreted as a marker of NO. METHODS AND RESULTS: We studied the expression of NOS-IR isoforms and NY-IR in 16 cases of B-cell non-Hodgkin's lymphoma (NHL) (five follicle centre cell lymphoma, four small lymphocytic/CLL, and seven diffuse large cell lymphoma), and 10 cases of multiple myeloma (MM). NOS1 was expressed in 5/10 cases of MM, and 15/16 cases of NHL. NOS2 was detected in all cases of MM, and in 14/16 cases of NHL, whereas NOS3 was positive in 3/10 of MM and in only in 1/16 cases of NHL. The expression of NY-IR was observed in 70% of MM cases, and in all cases of B-cell NHL, in a dot-like pattern in few tumour cells. CONCLUSIONS: B-cell neoplasms express neuronal and inducible NOS, and nitrotyrosine. Taken together, our results suggest that B-cell neoplasms can produce NO. The role of NO in the biology, diagnosis and prognosis of B-cell neoplasms remains to be established.

Adult↗

PubMed2001

Transfer of clarithromycin to gastric juice is enhanced by omeprazole in Helicobacter pylori-infected individuals.

BACKGROUND: The effects of proton-pump inhibitors and Helicobacter pylori infection on the distribution of drugs employed for the eradication of H. pylori are poorly understood. The aim of this study was to investigate the effects of a 7-day oral administration of 20 mg omeprazole on the distribution of clarithromycin in the gastric juice of individuals with H. pylori infection. METHODS: Eighteen H. pylori-infected dyspeptic male volunteers without endoscopic lesions were enrolled in a study with an open, randomized, two-period crossover design and a 21-day washout period between phases. Plasma and gastric juice concentrations of clarithromycin in subjects with and without omeprazole pretreatment were measured by means of liquid chromatography coupled to tandem mass spectrometry. RESULTS: The maximum concentration of clarithromycin (Cmax) and the area under the time-concentration curve from 0 to 2 h (AUC0-2h) were significantly higher in gastric juice than in plasma. Omeprazole treatment further augmented clarithromycin Cmax and AUC0-2h in gastric juice approximately 2-fold (P < 0.05). CONCLUSIONS: Short-term treatment with omeprazole in H. pylori-positive volunteers increases the amount of clarithromycin transferred to the gastric juice, confirming a synergism between these drugs. Our results suggest the presence of an active transport mechanism for clarithromycin from plasma to the gastric lumen, which is influenced by omeprazole.

Adult↗

PubMed2001

Terbinafine quantification in human plasma by high-performance liquid chromatography coupled to electrospray tandem mass spectrometry: application to a bioequivalence study.

A method based on liquid chromatography with positive ion electrospray ionization and tandem mass spectrometry is described for the determination of terbinafine in human plasma using naftifine as internal standard. The method has a chromatographic run time of 5 minutes and was linear in the range 1.0 to 2000 ng/mL. The limit of quantification was 1.0 ng/mL; the intraday precision was 3.6%, 3.8%, 3.5%, and 4.1%; and the intraday accuracy was -2.7%, 7.7%, 4.8%, and -2.7% for 5.0, 80.0, 250.0, and 1500.0 ng/mL, respectively. The interday precision was 4.9%, 1.7%, 2.4%, and 4.6% and the interday accuracy was 0.3%, 5.8%, 6.5%, and -1.4% for the same concentrations. This method was used in a bioequivalence study of two tablet formulations of terbinafine. Twenty-four healthy volunteers (both sexes) received a single oral dose of terbinafine (250 mg) in an open, randomized, two-period crossover study. The 90% CI of geometric mean ratios between Terbinafina (Medley S/A Indústria Farmacêutica, Campinas, Brazil) and Lamisil (Novartis Biociências S/A, São Paulo, Brazil) were 90.5% to 110.0% for C max, 92.2% to 108.1% for AUC last, and 91.3% to 107.5% for AUC 0-inf. Because the 90% CI for the above-mentioned parameters were included in the 80% to 125% interval proposed by the US FDA, the two formulations were considered bioequivalent in terms of rate and extent of absorption.

Antifungal Agents↗

PubMed2000

Platelets induce human umbilical vein endothelial cell proliferation through P-selectin.

We studied whether platelets could participate in the endothelial cell monolayer regeneration in the case of a vessel damage. Incorporation of [3H]-thymidine into the DNA of human umbilical vein endothelial cells (HUVECs) was measured after 48 h of co-incubation with platelets. The effect of platelets was compared to that of platelet-free supernatants from thrombin-activated platelets that had secreted their active granule constituents. Platelets dose-dependently induced HUVEC proliferation. Platelets preactivated by thrombin induced similar proliferation as did unactivated platelets (proliferation factor = 7 - 8), indicating that preactivation of platelets was not required. Platelets fixed with paraformaldehyde had no effect, suggesting that the platelet mitogenic effect required a mobile, alive membrane. Ketanserine and suramin reduced by at most 30 % the platelet-induced proliferation; supernatants of thrombin-activated platelets caused only minor proliferation (proliferation factor = 2), suggesting that secreted 5-hydroxytryptamine and growth factors poorly contributed to the proliferative effect. When the co-incubation was performed in the presence of an anti P-selectin antibody, the platelet-induced HUVEC proliferation was inhibited. The results suggest that platelet adhesion participate in the control of the endothelial regeneration and that platelet P-selectin is a molecular determinant of the proliferative signal.

Aspirin↗

PubMed2000

Determination of 21-hydroxydeflazacort in human plasma by high-performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry. Application to bioequivalence study.

A liquid chromatographic atmospheric pressure chemical ionization tandem mass spectrometric method is described for the determination of 21-hydroxydeflazacort in human plasma using dexamethasone 21-acetate as an internal standard. The procedure requires a single diethyl ether extraction. After evaporation of the solvent under a nitrogen flow, the analytes are reconstituted in the mobile phase, chromatographed on a C18 reversed-phase column and analyzed by mass spectrometry via a heated nebulizer interface where they are detected by multiple reaction monitoring. The method has a chromatographic run time of less than 5 min and a linear calibration curve with a range of 1-400 ng ml(-1) (r>0.999). The between-run precision, based on the relative standard deviation for replicate quality controls, was < or =5.5% (10 ng ml(-1)), 1.0% (50 ng ml(-1)) and 2.7% (200 ng ml(-1)). The between-run accuracy was +/-7.1, 3.8 and 4.8% for the above concentrations, respectively. This method was employed in a bioequivalence study of two DFZ tablet formulations (Denacen from Marjan Industria e Comercio, Brazil, as a test formulation, and Calcort from Merrell Lepetit, Brazil, as a reference formulation) in 24 healthy volunteers of both sexes who received a single 30 mg dose of each formulation. The study was conducted using an open, randomized, two-period crossover design with a 7-day washout interval. The 90% confidence interval (CI) of the individual geometric mean ratio for Denacen/Calcort was 89.8-109.5% for area under the curve AUC(0-24 h) and 80.7-98.5% for Cmax. Since both the 90% CI for AUC(0-24 h) and Cmax were included in the 80-125% interval proposed by the US Food and Drug Administration, Denacen was considered bioequivalent to Calcort according to both the rate and extent of absorption.

Adolescent↗

PubMed2000

Effect of crotapotin and heparin on the rat paw oedema induced by different secretory phospholipases A2.

The effects of crotapotin (a non-toxic and non-enzymatic acid polypeptide naturally complexed with phospholipase A2) and heparin on rat paw edema induced by different secretory phospholipases A2 (sPLA2) have been investigated. The ability of crotapotin to affect the enzymatic activity of the sPLA2(s) have also been evaluated. Secretory PLA2(s) obtained from both snake (Naja naja, Naja mocambique mocambique, Crotalus adamanteus and Crotalus durissus terrificus) and bee (Apis mellifera) venoms as well as that from bovine pancreas were used in this study. Rat paw oedema was induced by a single subplantar injection of the sPLA2s (5-30 microg/paw) in absence and presence of either crotapotin (10-100 microg/paw) or heparin (50 U/paw). Paw volume was measured using a hydroplethysmometer. Phospholipase A2 from Naja naja, Naja mocambique mocambique, Apis mellifera venoms and the basic component of Crotalus durissus terrificus venom all induced dose-dependent rat paw oedema whereas those from Crotalus adamanteus venom and bovine pancreas were ineffective. Paw oedema induced by PLA2(s) from both Naja naja and Apis mellifera venoms was significantly (P < 0.05) inhibited by crotapotin (0.1-100 microg/site) whereas the Naja mocambique mocambique venom PLA2-induced oedema was significantly potentiated (P < 0.05) by this polypeptide (40 microg/site). On the other hand, heparin (50 U/paw) had no effect on the paw oedema induced by PLA2 from Naja naja and Apis mellifera venoms but significantly inhibited the Naja mocambique mocambique venom PLA2-induced oedema. The measurement of the in vitro phospholipasic activity revealed that crotapotin inhibited by 60-70% the enzymatic activities of PLA2(s) from Crotalus adamanteus, Naja mocambique mocambique, Apis mellifera venoms and bovine pancreas. Our results suggest that despite the great homology between the various types of sPLA2 they interact with crotapotin on cell surfaces in different ways leading to either inhibition or potentiation of the paw oedema by a mechanism unrelated to their enzymatic activities. Since heparin reduced paw oedema induced by PLA2 from Naja mocambique mocambique venom it is likely that this sPLA2 is similar to the novel heparin-sensitive PLA2 found in mast cells.

Animals↗

PubMed2000

Development of an experimental model of liver cirrhosis in rabbits.

1. The aim of the present study was to develop an experimental model of liver cirrhosis in rabbits using CCl4 and phenobarbital. 2. Liver cirrhosis was induced in male New Zealand white rabbits (n = 10) by intragastric administration of CCl4 once weekly starting 14 days after the addition of phenobarbital to the drinking water (50 mg/day). Controls received phenobarbital only (n = 7). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), albumin and bilirubin levels were determined throughout CCl4 treatment. The initial dose of CCl4 was 20 microg and subsequent doses were calculated to maintain AST and ALT levels between 400 and 800 IU/L for the duration of treatment (16 weeks). Indocyanine green (ICG) clearance was performed before and at the end of CCl4 treatment. Animals were killed at 16 weeks and three fragments of each liver lobe were processed for histological examination. A semiquantitative score was used to evaluate the development of fibrosis. 3. Cirrhosis developed in 80% of rabbits treated with CCl4. These animals did not gain weight compared with controls (P < 0.05). A significant reduction of ICG clearance was observed in CCl4-treated rabbits compared with controls (P < 0.05). The AST, ALT, bilirubin and gamma-GGT levels were elevated in CCl4-treated rabbits. 4. In conclusion, this model is successful in producing liver cirrhosis and may be useful in studies investigating metabolic, immunological or biochemical changes during the evolution of chronic liver disease.

Animals↗