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Biomedical subjects

B I Verkin

Publications and source records attributed to B I Verkin.

16 recordsLinked to original sources
PubMed1977

Preliminary morphological and X-ray diffraction studies of the crystals of the DNA cetyltrimethylammonium salt.

Double-stranded DNA molecules (molecular weight 2.5 X 10(5) - 5 X 10(5) daltons) have been crystallized from water-salt solutions as cetyltrimethylammonium salts (CTA-DNA). Variation of crystallization conditions results in a production of different types of CTA-DNA crystals: spherulits, dendrites, needle-shaped and faceted rhombic crystals, the latter beeing up to 0.3 mm on a side. X-ray diffraction data indicate that DNA molecules in the crystals form a hexagonal lattice which parameters vary slightly with the morphological type of the crystal. Comparison of the melting curves of the DNA preparation before and after crystallization suggests that DNA molecules are partially fractionated in the course of crystallization. Crystals of the CTA-DNA-proflavine complex have also been obtained.

Cetrimonium Compounds↗
PubMed1976

Crystallization of DNA fragments from water-salt solutions, containing 2-methylpentane-2,3-diol.

Fragments of calf thymus DNA have been crystallized by precipitation from water-salt solutions, containing 2-methylpentane-2,3-diol (MPD). DNA crystals usually take the form either of spherulites up to 100 mu in diameter or of needles with the length up to 50 mu. No irreversible denaturation of DNA occurs during the crystallization process. X-ray diffraction from dense slurries of DNA crystals yields crystalline powder patterns.

Cacodylic Acid↗
PubMedDate not supplied

[Cryosurgical applicator in dermatology].

An autonomous dermatological applicator is proposed for cryological destruction of pathologically altered sections of the skin. It is equipped with a set of interchangeable tips permitting it to treat different areas of the skin. The temperature and the force of contact of the tip with the tissue are adjustable. As a refrigerant liquid nitrogen is made use of.

Adolescent↗
PubMedDate not supplied

[Improved model of cryosprayer].

For local congelation of pathologically altered sections of the tissue the design of an earlier devised cryosprayer has been improved. The newly constructed model is convenient in handling, reliable in operation, has low weight and overall dimensions and ensures good visual view of the operation field. The new model of the cryosprayer is recommended for use in the stomatological practice, for treatment precarcinous affections of the buccal mucosa and dental pulp.

Cryosurgery↗
PubMedDate not supplied

[Cryogenic technic in gynecological practice].

Two units with different refrigerants and cooling temperature are recommended for treating various gynecological affections by the method of cryodestruction of pathological changes in the cervical tissue and the uterine mucosa. In these liquid nitrogen, nitrous oxide and carbon dioxide are employed as refrigerants.

Cryosurgery↗
PubMedDate not supplied

[The effects of weak magnetic fields on bacteria].

A stationary device was constructed for conducting experiments in a weak magnetic field. A ferromagnetic screen was used to produce in the working volume a magnetic-field of 26 nT. The effect of a weak magnetic field on the following bacteria was studied: E. coli communior, B. prodigiosum, Staphylococcus aureus 209, and Bac. anthracoides. Cultivation of the bacteria in these conditions for a long time resulted in changes of their tinctorial, morphological, cultural, and biochemical properties.

Bacillus cereus↗
PubMedDate not supplied

[Apparatus for cryosurgery in gynecology].

A new cryosurgical apparatus, model AKT-01 for treatment of erosions, uterine cervix polyps, pointed condylomas and for cryocoagulation of the uterine mucosa has been designed. As a refrigerant nitrous oxide is employed in the apparatus. The latter made up of a cryoprobe, a stand and a cylinder with compressed nitrous oxide is mounted on a trolley. The cryogenic action on the tissue is exerted by interchangeable tips cooled down to--70 degrees with the cryogenic action lasting for 2--5 minutes.

Condylomata Acuminata↗
PubMedDate not supplied

[Self-contained neurosurgical cryoprobe].

A cryoprobe with an interchangeable container (vessel) holding the cryoprobe has been designed, this enabling it to dispense with the use of hoses to deliver the coolant to and remove it from the Dewar vessel and the vacuum pump. The cryogenic action provided for by a single ampoule lasts 5 minutes. The small diameter of the cryoprobe makes for a minimal traumatization of the surrounding structures, while the absence of connecting hoses makes for its easy handling.

Cryosurgery↗
PubMedDate not supplied

[Cryosurgical treatment of tumors of the cerebral hemispheres].

A technique of cryosurgical removal of extra- and intracerebral tumours of the hemispheres of the brain was developed. The employed cryosurgical device was provided with a cryoprobe featuring an instrument fixed in a handle and having a vacuum-insulated line of supply and removal of the cold-carrying agent (liquid nitrogen). The separation of the tumour from the surrounding brain tissue and the control of haemorrhage from the cerebral vessels was performed with the aid of a cryocoagulator connected with the cryosurgical device. An analysis of 64 cryosurgical interventions demonstrated that the employment of the cryosurgical method helps to prevent cerebrovascular disorders, and to decrease the degree of brain oedema-swelling.

Astrocytoma↗