Synthesis of betulinic acid from betulin and study of its solubilization usingliposomes

A method for betulinic acid synthesis from betulin was developed. Betulin was oxidized with chromium oxide (VI) into betulonic acid, which was reduced with sodium borohydride to yield a mixture of 3-hydroxy epimers containing 85% of the natural beta-epimer. Studying changes in light scattering by dispersions of liposomes with different contents of betulinic acid revealed that up to 10 mol % of this compound may be entrapped in liposomes. The dependence of the efficiency of the betulinic acid entrapment on liposome composition was studied. The presence of polyvinylpyrrolidone or Proxanol increased the resistance of betulinic acid-containing liposomes to aggregation. These polymers solubilized betulinic acid with the same efficiency as liposomes.     

Why is the eye round?

By an unsophisticated experiment, published data on the anatomy of the eye, wave theory of light, and the laws of geometrical optics the author tries to prove that a spherical concave screen is the optimal variant of a screen on which spherical wave front is projected, formed by a single lens. The shape of the wave front and of the concave screen are in complete agreement. Such optical imperfections as the field curvature, distortion, coma (partially), and astigmatism of the oblique light beams are compensated for. These optical drawbacks are undetectable on a concave screen, and hence they are proposed to be the shortcomings of a flat screen. The author compares this to a spherical shape of the eye, the posterior wall of which represents a concave screen, an indisputable fact, and assumes that the before-named optic imperfections are completely compensated for in human eye due to concavity of the posterior optic wall. Based on the anatomy and practical results of using aspherical refracting surfaces in artificial optic devices, the author draws a parallel with the anatomical structures of the eye possessing aspherical refracting surfaces in order to demonstrate that higher and lower-order spherical aberrations (Zeidel's aberrations) are fully compensated for in human eye, as are the position and enlargement chromatism. Analysis of published data permitted the author to assert that the eye of man is characterized by a method for compensation of spherical aberrations, which has no analogs in man-made practice. Hence, the Nature has imparted the eye with such a collection of compact, universal, and highly effective methods for compensation of optic imperfections, which is not to be found in any of the man-made devices of today.     

Proportion of the GSTM1 0/0 genotype in some Slavic populations and its correlation with cystic fibrosis and some multifactorial diseases

A homozygous gene deletion at the glutathione S-transferase M1 (GSTM1) locus of genomic DNA from blood spots was studied by PCR in the group of Slavic populations from the north-western and central-eastern regions of European Russia and in patients with lung cancer (LC), other tumors (OT), endometriosis (E), alcoholic cirrhosis (AC), cystic fibrosis (CF) and chronic bronchitis (CB). The frequencies of the GSTM1 0/0 genotype were 38.8% and 67.5% for both population groups, respectively. The proportion of the GSTM1 gene deletion genotype was estimated as significantly increased in LC (81%), OT (65%), E (81%), AC (77.3%), and in CB (73.6%) patients with symptoms of CB confirmed by X-ray but not in CB patients without X-ray evidence of disease (40.9%). A definite preponderance of GSTM1-0 homozygotes (51.1%) has been registered in CF patients of the pancreatic sufficient group with clear-cut pulmonological manifestations but not in those of the pancreatic insufficient group with predominantly intestinal or mixed clinical symptoms (41.2% and 37.5%, respectively). Earlier clinical manifestations and death before the age of 5 years are typical for GSTM1-deleted CF patients. These data support the notion that GSTM1 deletion should be considered as a convenient genetic marker for the early detection of groups at higher risk of many diseases caused by environmental and genetic factors, where manifestation depends on the lack of detoxification. High levels of GSTM1 0/0 genotypes in E patients favor the substantial contribution of certain environmental toxins in the pathogenesis of this widespread disease.     

Quantitative and ultrastructural analysis of rectal mucosal mast cells in acute infectious diarrhea

The role of mast cells, potential mediators of mucosal immunity and inflammation, was studied morphologically in the rectal mucosa in two acute diarrheal diseases, cholera and shigellosis. Quantitation of mucosal mast cells showed that they were significantly higher in the deeper lamina propria where blood vessels and nerves were more abundant. There was no difference in mast cell counts or degranulation in the mucosa in both groups of patients and controls. Intraepithelial mast cells were decreased in the patients. The prevalence of lipid bodies was significantly higher in mast cells from patients with cholera and shigellosis (P < 0.01). These findings suggest that mast cell populations are more dense around blood vessels and nerves and that inflammatory mediators derived from arachidonic acid metabolites, as indicated by the lipid bodies, are the response of mast cells to the alterations in diarrhea, despite differences in the etiology of diarrhea.     

Ophthalmic tone of myopic eyes: statistical evaluation and role in formation of acquired myopia

The author summarizes the results of many-year profound statistical analysis of ophthalmic tone in myopic patients. Intraocular pressure (IOP) of myopic eyes in patients aged 10 to 62 years and refraction from 0.5 to -24.0 diopters was measured in 1220 eyes by the same type of Goldman's tonometer. Detailed distribution of IOP for age and refraction factor is presented. IOP has been studied in emmetropia, stable and progressive myopia, and in paired anisometropic eyes. The author emphasizes that myopia progresses at various levels of ophthalmic tone, whose increase is mainly functional and reversible, and is caused by organic changes in the anterior chamber angle in only 7% of cases. The author claims that IOP is an important characteristic of a myopic eye and is to be taken into consideration when prescribing pathogenetic therapy for progressive myopia.     

Standards of anesthesiological and intensive care

A case of flutamide photosensitivity is reported in a patient receiving treatment for prostate cancer. Photopatch testing with flutamide at 10 and 20% in acetone was positive and controls negative. Other reports in the literature indicate that flutamide photosensitivity can be produced either by UV-A or UV-B, but the small number of reports and the differences in the tests performed do not allow the specific characteristics of flutamide photosensitivity to be established. Presently it would be advisable, due to the frequent use of this drug, to include flutamide in the investigation of photosensitive patients.