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Biomedical subjects

A Gasmi

Publications and source records attributed to A Gasmi.

10 recordsLinked to original sources

[Impact of diabetes on mortality after myocardial infarction].

UNLABELLED: Myocardial infarction is a common cause of mortality in people with diabetes. The aim of this study was to determine early and mid-term mortality in diabetic patients with myocardial infarction and to determine if hyperglycemia was predictor of mortality. We conducted a retrospective study of 100 diabetic patients compared with 100 non diabetic patients who were hospitalised in our institution between 1999 and 2003 for myocardial infarction. RESULTS: Hospital and one year mortality were highest among diabetic patients compared with non diabetic patients. Multivariate analysis showed that admission plasma glucose was a consistent predictor factor of in hospital mortality RR 1.2 (IC 1.02-1.47). Admission plasma glucose was significantly higher in nonsurvivors diabetic patients than in survivors (22.7 vs 16 mmol/l P = 0.04). The predictor factors of one year mortality was age, female sex and no beta blocker at discharge RR5.3 (1.9-14.3). CONCLUSION: Diabetic patients with myocardial infarction have poor prognosis and hyperglycemia was associated with in hospital mortality.

Adrenergic beta-Antagonists↗

Amino acid structure and characterization of a heterodimeric disintegrin from Vipera lebetina venom.

A heterodimeric disintegrin designed as lebein was isolated from crude Vipera lebetina venom using gel filtration, anion and cation exchange chromatographies on FPLC. The amino acid sequence of each subunit determined by Edman degradation contains 64 residues with ten half-cystines and an RGD site at the C-terminal part of the molecule. The molecular mass of native lebein determined by mass spectrometry was found to be 14083.4 Da and those of alpha and beta subunits were 6992.05 and 7117.62, respectively. These value are in good agreement with those calculated from the sequences. This protein strongly inhibits ADP induced platelet aggregation on human platelet rich plasma with IC(50)=160 nM. Sequences of this protein subunits displayed significant sequence similarities with many other monomeric and dimeric disintegrins reported from snake venoms. We identified an amino acid residue (N) in the hairpin loop of both subunits (CNRARGDDMNDYC) which is different from all other reported motifs of disintegrins and this subtle difference may contribute to the distinct affinities and selectivities of this class of proteins.

Amino Acid Sequence↗

Amino acid sequence of VlF: identification in the C-terminal domain of residues common to non-hemorrhagic metalloproteinases from snake venoms.

The complete amino acid sequence of a non-hemorrhagic fibrino(geno)lytic enzyme (VlF) isolated from Vipera lebetina venom has been determined. VlF was subjected to separate enzymatic and chemical digestions. Resulting fragments were purified by RP-HPLC and subjected for sequencing by automated Edman degradation. The amino terminus of VlF was determined by mass spectrometry. VlF was shown to be composed of 202 residues having a relative molecular mass of 22,826 Da and containing a zinc-binding site and a catalytically active residue. It displayed significant sequence similarities with many other mature metalloproteinases reported from snake venoms. Sequence comparison of hemorrhagic and non-hemorrhagic mature metalloproteinases revealed the presence at the C-terminal part of the enzymes of two residues common to only hemorrhagic metalloproteinases and two others shared by only non-hemorrhagic ones.

Amino Acid Sequence↗

Purification and characterization of a growth factor-like which increases capillary permeability from Vipera lebetina venom.

We have investigated the effect of Vipera lebetina venom on capillary permeability and isolated an increasing capillary permeability protein (ICPP) which is devoid of arginine ester hydrolase and phospholipase A2 activities. This protein was purified with a yield of about 0.2% by fast protein liquid chromatography (FPLC) using successively Superose 12, Mono Q, and Mono S columns and by high-pressure liquid chromatography (HPLC) on a C8 reverse-phase column. The purified protein migrated on SDS-PAGE as a band of about 27 kDa under nonreducing conditions and as a band of about 16 kDa under reducing conditions. Chromatography on a C8 column of reduced and alkylated protein yielded a single peak suggesting that this protein is homodimeric. This protein was refractory to Edman degradation chemistry. We used successfully a chemical unblocking involving the incubation of the protein with HCl in anhydrous methanol. The N-terminal amino acid sequence clearly shows considerable similarity to that of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF).

Amino Acid Sequence↗

Further characterization and thrombolytic activity in a rat model of a fibrinogenase from Vipera lebetina venom.

Vipera lebetina fibrinogenase (VlF) was shown to render fibrinogen incoagulable and to solubilize fibrin. The fibrinogenolytic activity of this enzyme was found to be 33 mg fibrinogen/min/mg protein. The study of the specificity of this enzyme revealed that it has no effect on purified factor X, prothrombin and protein C and on the specific chromogenic substrates of their active form. Plasminogen was not activated by VlF but slightly degraded. We have also compared the effect of VlF and plasmin on fibrinogen and shown that these two enzymes have a different sites of cleavage. This enzyme inhibited human platelet aggregation on PRP initiated by ADP and collagen but was without effect on the aggregation of washed rabbit platelets using thrombin as agonist. Administration of VlF in rat did not show any necrosis or hemorrhage in treated rats organ's. We therefore, examined the thrombolytic activity of VlF in a rat model of venous thrombosis. Thrombus was produced in the posterior vena cava by injection of human fibrinogen and thrombin. Injection of 5 mg/Kg body weight showed an evident flow restoration after one hour and measurement of the fibrinogen level a decrease of about 30% after 3 hrs. VlF's action is not dependent on plasminogen activators and may act synergistically with them, thereby providing an intriguing potential clinical application for dissolution of blood clots.

Animals↗

Acute selenium poisoning.

Reports of acute human selenium toxicity are rare. We report 2 new cases. One patient ingested a mouthful of selenic acid (30 g/L); he only suffered mild gastrointestinal disturbances. Serial measurements of plasma selenium concentrations were performed. The first plasma level was obtained 3 h after ingestion and was the highest (931 micrograms/L); plasma concentrations subsequently decreased with a half-life of 17.5 h. The second patient ingested 1.7 g of sodium selenite. He suffered severe gastroenteritis, had transient electrocardiographic changes and developed a slight elevation of serum bilirubin. The first serum concentration measurement was performed 3 h after ingestion; the selenium level was 2.716 micrograms/L. These data are compared to those from other published cases. The prognostic significance of the blood selenium concentration is discussed.

Adult↗

Purification from Vipera lebetina (desert adder) venom of a protein that depletes human complement.

A rapid and efficient procedure for purification from Vipera lebetina venom of a low molecular weight anticomplement protein is described. The procedure used gel filtration on Superose 12, followed by ion-exchange chromatography on a Mono Q column. The purified protein migrated on SDS-PAGE as a single band of about 25,000 Da under nonreducing conditions and as a band of 16,000 Da under reducing conditions. Its isoelectric point was estimated to be 7.6 +/- 0.1. The isolated Vipera lebetina protein was found to decrease the hemolytic activity in human serum measured by assays for classical pathway and alternative pathway activation. The loss of the complement activity could be ascribed, at least in part, to a proteolytic cleavage of the alpha chains of C3 and C4. This protein was also found to be without action on human blood coagulation and on purified fibrinogen and Factor B.

Blood Coagulation↗

Purification and characterization of a fibrinogenase from Vipera lebetina (desert adder) venom.

A fibrinogenase from Vipera lebetina venom was isolated by gel filtration in a Superose 12 column prep grade HR 16/50 and by ion-exchange in a Mono Q HR 5/5 column. The purified enzyme, which was obtained with a yield of 8 mg from 60 mg of crude venom, is a glycoprotein having an isoelectric point of 5.9 +/- 0.1 and a mol. wt of 26,000 +/- 1000 as estimated by SDS-PAGE. The biochemical characterization of the enzyme revealed that it hydrolyzes readily the B beta chain of fibrinogen and the A alpha chain as well as fibrin and casein. Over a pH range from 4 to 11 the enzyme was not inactivated by a 20 min treatment at 90 degrees C. The isolated fibrinogenase is inhibited by ethylenediamine tetraacetic acid, dithiothreitol and L-cysteine but not by phenylmethylsulfonyl fluoride. On the other hand, it is activated by Ca2+ and Mg2+. Purified fibrinogenase up to a dose of 100 micrograms/mouse shows no toxicity and has no hemorrhagic activity.

Animals↗