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Biomedical subjects

M Zamfir

Publications and source records attributed to M Zamfir.

6 recordsLinked to original sources

Production kinetics of acidophilin 801, a bacteriocin produced by Lactobacillus acidophilus IBB 801.

Lactobacillus acidophilus IBB 801 produces a small bacteriocin, designated acidophilin 801. Studying the relationship between growth and bacteriocin biosynthesis revealed primary metabolite kinetics of bacteriocin production with a peak activity at the end of the exponential growth phase followed by a decrease during the stationary phase. Both microbial growth and bacteriocin production was inhibited by lactic acid. Whereas volumetric bacteriocin production (activity units (AU) ml(-1)) was favoured under pH-controlled conditions, bacteriocin titres rapidly decreased because of strong adsorption of the bacteriocin molecules to the producing cells under less acidic conditions.

Bacteriocins↗

Purification and characterization of a bacteriocin produced by Lactobacillus acidophilus IBB 801.

Lactobacillus acidophilus IBB 801 produces a small bacteriocin, designated acidophilin 801, with an estimated molecular mass of less than 6.5 kDa. It displays a narrow inhibitory spectrum (only related lactobacilli but including the Gram-negative pathogenic bacteria Escherichia coli Row and Salmonella panama 1467) with a bactericidal activity. The antimicrobial activity of cell-free culture supernatant fluid was insensitive to catalase but sensitive to proteolytic enzymes such as trypsin, proteinase K and pronase, heat-stable (30 min at 121 degrees C), and maintained in a wide pH range. The proteinaceous compound was isolated from cell-free culture supernatant fluid and purified. Crude bacteriocin was isolated as a floating pellicle after ammonium sulphate precipitation (40% saturation) and partially purified by extraction/precipitation with chloroform/methanol (2/1, v/v). Further purification to homogeneity was performed by reversed phase Fast Performance Liquid Chromatography. The amino acid composition was determined. Amino acid sequencing revealed that the N-terminal end was blocked.

Bacteriocins↗

[Intermesenteric anastomoses].

This work is based on dissection and the analysis of the arteriographies of two mesenteric arteries and it analyses the type of intermesenteric anastomoses and their importance in surgical practice. The morphological varieties of Riolan's arcade depends on its pillars, as well as on the eventual presence, especially in the middle part of the transversal mesocolon, of the secondary arcades; it seems that the colic wall necrosis depends less upon the location of the lesion or the level of the suture of the arcade, but more so on the stretch of the destruction of the mesocolon. The intermesenteric trunk, a second way of intermesenteric anastomoses is a embryological remaining, non-functional in normal conditions, but capable to partially or completely replace the Riolan's arcade when the later is sutured or interrupted.

Angiography↗

[The interpretation of the telomic distribution of the pulmonary arterial trunk].

The analytical study of the periodicity of organic processes is of great interest as reflected by the literature. This paper aims at describing the functional implications from the viewpoint of pulmonary functional arterial circulation regularity. In the light of morphological aspects, the pressure falls along a symmetric telomic tree were followed up and compared with the experimentally obtained data.

Barium Sulfate↗