Nuclear magnetic tomography in the diagnosis of spinal cord cysts]

Magnetic resonance tomography (MRT) was used in examinations of 172 patients with spinal cord abnormalities. Thirty-eight cysts were detected: 25 in syringomyelia, 5 in intramedullary tumors, 4 posttraumatic and 4 postoperational ones. Based on the MRT patterns, two types of syringomyelia were distinguished, the occlusive and idiopathic ones. The size and site of cyst, as shown by the MRT, did not conform to its neurologic symptoms. A characteristic feature of tumorous cysts was a highly intensive signal originating from their contents. Traumatic cysts were detected against the background of diffuse atrophy of the cord. Computer-aided tomography did not give full-value information in such cases and therefore could not be recommended in cases with suspected intramedullary cysts.     

On the content of protein and nucleic acids in organs of chick embryos of different age

In 10-, 14-and 18-days-old chick embryos, concentrations of total protein and nucleic acids (NA) were measured using spectrophotometry in liver, brain, red gastrocnemial and white pectoral muscles and in chorioallantois. It was shown that the initial protein and NA concentration was the highest in liver and decreased markedly in the above-mentioned organs. At the second half of embryogenesis, concentration of organ protein increased 4 times in muscles, 2 times in brain, and 1.4 times in liver. This indicates a rise of cell density in the organs or of the intracellular protein concentration. The protein/NA ratio reflecting the cell size or concentration of their protein practically did not change in liver, but increased 2.3 and 2.5 times in pectoral and gastrocnemial muscles, respectively, and 2 times in brain. In chorioallantois the maximal protein concentration was observed in then 14-day old embryos, with the protein/NA ratio remaining practically unchanged.     

Introduction of the human recombinant angiogenin at the early stages of postnatal development inhibits the growth of mice

We studied the influence of recombinant DNA containing the cloned angiogenin gene, plasmid DNA without angiogenin gene, and purified recombinant angiogenin injected to Tg8 mice at the age of two days on the body mass of 28- and 40-day old mice. The body mass of mice that were injected with the cloned angiogenin gene or purified angiogenin was less than in the control mice. The body mice of Tg8 mice injected with recombinant DNA containing the cloned angiogenin gene did not increase from day 2 to day 40, while in the mice with purified recombinant angiogenin and control mice it increased by 24 and 57%, respectively. These data suggest that the elevated level of angiogenin at the early developmental stages inhibits the increase of body mass. The effect we described as related, in al likelihood, to the known inhibitory effect of angiogenin on protein synthesis.     

Effects of native and oxidized apolipoprotein A-I on lipid bilayer microviscosity of erythrocyte plasma membrane

Using a pyrene as a fluorescent probe, we investigated the influence of native and oxidized apolipoprotein A-I (apo A-I) and their complexes with tetrahydrocortisol (THC) on the microviscosity of the erythrocyte plasma membrane. The addition of THC to isolated membranes led to a 17% increase in the membrane microviscosity. In contrast, native apo A-I reduced the microviscosity (i.e., increased the fluidity) of the membranes by 15%. A more pronounced increase (by 25%) in the membrane fluidity was found in the presence of the complex of apo A-I with THC. Unlike native apo A-I, oxidized apo A-I and its complex with THC did not change the membrane viscosity. In view of the fact that apo A-I plays an important role in the binding of membrane cholesterol we suggest that the observed increase in the membrane fluidity under the influence of the native apo A-I is associated with the cholesterol efflux from plasma membrane. Oxidative modification of apo A-I likely disturbs the mechanisms of the cholesterol efflux and prevents the decrease in the membrane microviscosity.     

Microspectrofluorimeter with an interference light filter of variable wavelength]

A highly sensitive portable microspectrofluorimeter with continuous interference filter for 400-700 nm spectrum, for investigation of living cells, is described.     

Ultra-low field magnetic resonance tomography in the diagnosis of diseases of the spine and spinal cord]

A total of 309 investigated cases was analyzed with the help of the Magnaview apparatus with field intensity of 0.04 T. The method included obtaining both T1- and T2-suspended tomograms in the sagittal and, if necessary, transverse planes. MRT was shown to be an effective method of diagnosis and differential diagnosis of the compression syndrome of osteochondrosis, the effects of a "spinal" trauma, extra- and intramedullary tumors, metastatic vertebral involvement, postoperative changes, and syringomyelia.