ABSTRACT
The study material included 105 isolated bone preparations of the atlas, 100 radiographs of the cervical region of the spine, 650 spiral computed tomography (SCT) scans and 224 protocols of duplex ultrasound scanning of extracranial portions of brachiocephalic arteries and transcranial duplex scanning. Kimmerle anomaly was detected in 18% of cases in the bone material, in 17% of the cases of SCT and in 15% of cases during radiological examination. The anomaly more often is unilateral, rarely--bilateral; it may be located medially or laterally, while the vertebral artery canal more frequently is closed, less commonly--open. Among the patients with Kimmerle anomaly, hemodynamically significant asymmetry of blood flow velocity in the vertebral arteries was detected in 78.5% of cases. Thus, the most important method of Kimmerle anomaly detection is SCT with contrast-enhanced artery imaging. However, each of the research methods successively. Each of research methods used consistently allows to obtain information both on anatomical variability of atlas developmental abnormalities (morphological characteristics) and on possible functional disorders, morphological basis of which is Kimmerle anomaly.
Subject(s)
Neck/anatomy & histology , Spine/anatomy & histology , Vertebral Artery/anatomy & histology , Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Neck/diagnostic imaging , Spine/diagnostic imaging , Tomography, Spiral Computed , Vertebral Artery/diagnostic imagingABSTRACT
The anticoagulant activity of low-molecular-weight heparin with an average molecular weight of 4.7 kD (LMWH-4.7) has been studied. This derivative was prepared from unfractionated heparin with the help of chitinolytic enzyme complex from Streptomyces kurssanovii. The antithrombin activity of LMWH-4.7 (aIla activity) was 72 +/- 9 IU/mg and the activity with respect to the blood coagulation factor Xa (aXa activity) was 200 +/- 33 IU/mg, which corresponded to an aXa/aIIa ratio of 2.8 (necessary for effective antithrombotic drugs). The aIIa and aXa activity exhibited a dose-dependent variation upon intravenous and subcutaneous injections in rabbits, so that a high aIIa/aXa ratio was retained: 5 min after the intravenous injection of a minimum dose (0.3 mg/kg), this ratio was 2, 7, and for a greater dose (3.0 mg/kg) it reached 3.8. Subcutaneous injections were followed by slow elimination of the anticoagulant within 24 h. LMWH-4.7 upon intraperitoneal injections produced a dose-dependent inhibition of a model thrombosis in rats. Complete inhibition was observed for a dose of 3 mg/kg. Thus, it is possible to obtain active LMW heparin with the help of chitinases.
Subject(s)
Anticoagulants/therapeutic use , Factor Xa/metabolism , Heparin, Low-Molecular-Weight/pharmacology , Prothrombin/metabolism , Thrombosis/drug therapy , Animals , Anticoagulants/administration & dosage , Anticoagulants/chemistry , Chitin/chemistry , Chitinases/chemistry , Factor Xa Inhibitors , Female , Heparin, Low-Molecular-Weight/administration & dosage , Heparin, Low-Molecular-Weight/chemistry , Male , Prothrombin/antagonists & inhibitors , Rabbits , Rats , Rats, Wistar , Streptomyces/chemistry , SwineABSTRACT
The possibility of enzymatic hydrolysis of chitosan was shown. The optimum conditions for the process are: sodium acetate buffer pH 6.0, 37 degrees C, 24 h, and the chitosan sulfate-protein volume ratio of 500:1 in the enzyme preparation. During hydrolysis, the intrinsic viscosity of chitosan sulfate solution decreased by a factor of 2.7.
