Polymeric complexes of the antiseptic katamin AB and their biological activity

Translated from Khimiko-farmatsevitcheskii Zhurnal, Vol. 25, No. 4, pp. 40–43, April, 1991.     

Acid hydrolysis of benzylpenicillin anilides

In an effort to determine the factors affecting penicillin stability in acid media, benzylpenicillin anilides were synthesized and subsequently hydrolyzed at 30° in a mixture of dimethylformamide and glycocoll buffer at a pH of 2.0. The log of the penicillin anilide-lactam ring amide bond hydrolysis velocity constant was found to vary linearly with the amine pK. The hydrolysis reaction was found to follow Hammet's equation. The value of the constant (–0.12) indicates insensitivity of the reaction to structural changes in the anilide molecule.Translated from Khimiko-Farmatsevticheskii Zhurnal, No. 2, pp. 14–17, February, 1967.     

Cellulose materials modified by antiseptics and their antimicrobial properties

Adsorption properties of dressing cellulose materials with respect to surfactant antiseptics were studied. These antiseptics are a complex of the copolymer of N-vinylpyrrolidone and crotonic acid with dimethylbenzylalkylammonium chloride (a synthetic polymer with a wide spectrum of antimicrobial effect) and its low molecular weight analogue (dimethylbenzylalkylammonium chloride). It was established that cellulose materials reversibly adsorb mentioned surfactant antiseptics depending on their concentration in the initial solutions. Maximum release of surfactant antiseptics is achieved at solutions at pH = 7.0. Microbiological tests of cellulose materials modified by antiseptics have shown that they exhibit antimicrobial activity. These results can be used in medical practice in clinics for imparting antimicrobial properties to dressing materials.     

Assessment of periprocedural hemodynamic changes in arteriovenous malformation vessels by endovascular dual-sensor guidewire

Endovascular embolization is an important modality in the treatment of brain AVMs. Nowadays staged embolization is the method of choice for the prevention of perioperative hemorrhagic complications.Current theory suggests that simultaneous occlusion of more than 60% of AVM volume induces significant redistribution local blood flow. That, in turn, may lead to hemorrhage due to AVM rupture. Aside from angiographic findings, there is still no method that predicts the degree of safe partial embolization. Intraluminal measurement of flow velocity and pressure in the vicinity of the AVM nidus might allow detecting the changes in local hemodynamics. That can provide a valuable data and shed the light on the origin of vascular catastrophes.Ten patients underwent 12 embolization sessions with intraluminal flow velocity and pressure monitoring. The measurements were performed by dual-sensor guidewire. The “Combomap” (Volcano) system with Combowire microguidewires was chosen for measurements, as there is a documented experience of safe use of said guidewires in the cerebral vasculature.The findings observed during the study matched empirical data as well as the current physiological hypothesis of AVM hemorrhage.In conjunction with DSA runs, intraluminal flow velocity and pressure monitoring has the potential to become a valuable tool in AVM treatment.     

Anti-Inflammatory and Antishock Water-Soluble Polyesters of Glucocorticoids with Low Level Systemic Toxicity

Purpose. The objective of this study was to evaluate the pharmacological activity of glucocorticoid hormones incorporated into the structure of water-soluble carbochain polymers via the esterified 21-CH₂OH group. Methods. Polymer analogs of glucocorticoids were prepared by radical copolymerization of l-vinyl-2-pyrrolidone with cortisol or dexamethasone 21-crotonates and crotonic acid or 2-(diethylamino) ethylcrotonate which served as ionogenic comonomers. Anti-inflammatory, immuno-suppressive and catabolic activities for ionogenic tertiary copolymers and previously prepared non-ionogenic binary copolymers were evaluated in standard animal models. The antishock activity of some of the copolymers was evaluated using the declamping shock model. Results. Water-soluble tertiary copolymers with a steroid content up to 14 mol% and an intrinsic viscosity up to 0.30 dl/g in ethanol were synthesized. It was shown that the copolymers were stable in aqueous solutions at pH 5.2–7.3. All of the polymers studied suppressed inflammatory reactions at the level of free hormones when administered interperitoneally. The antishock activity was considerably higher compared to free steroids. The copolymers, unlike unmodified glucocorticoids, did not influence the physical development of young animals. They also caused much lower thymus hypotrophy than free hormones. No clear effect of the presence and nature of ionogenic units in copolymers on the pharmacological performance of the copolymers was detected. Conclusions. The water-soluble polymers bearing glucocorticoid 21-residues in the side chains retain the anti-inflammatory activity of free steroids and exhibit a higher antishock, a lower immunosuppressive and no catabolic effect.