[Regulation of 1-dehydrogenation and 20 beta-reduction of ketosteroids by microorganisms]. Regulation of two microbiological processes--1-dehydrogenation and 20 beta-reduction of ketosteroids--was studied using several exogeneous quinones which (a) stimulated 1-dehydrogenation and (b) inhibited the accompanying reaction, the reduction of 20-ketogroup of the steroid molecule. The least active compounds were benzoquinones. The best regulators are 1,4-naphthoquinone, 1,2-naphthoquinone, and 7-methoxy-1,2-naphthoquinone. Possible mechanism of the action of naphthoquinones on Mycobacterium globiforme is discussed.


[Variety of effects of vitamins on yeast cells in aerobic conditions]. The effect of thiamine and biotin on the processes of cell division, assimilation of glucose, and accumulation of the biomass and nitrogen in the cells was studied with the Candida yeast. The action of the vitamins depended on the source of nitrogen. In some strains,  asparagine can substitute for biotin. Biotin has different effect on the production of gamma-aminobutyric acid in Candida pulcherrima, C. guilliermondii. C. tropicalis K3-10. High concentrations of arginine were found in C. guilliermondii var. membranaefaciens in the presence of biotin. The vitamins did not favour the assimilation of nitrate nitrogen in species which were not adapted to this source of nitrogen.


[Determination of optical activity of the growth medium as a method for detection of extraterrestrial life]. Determination of optical activity of the cultural medium can be used for detection of extraterrestrial life. The composition of the growth medium depends on the duration of the experiment. Automatic biological stations are sent to planets for a short time, and the best components of the growth medium are D-glucose and D-maltose; optical activity of the cultural broth disappears upon assimilation of these compounds. Tartaric acid is less suitable since the duration of the experiment increases several times and desert soils do not always contain microorganisms assimilating tartaric acid.


[Effect of the composition of the medium and magnesium and calcium ions on the germination of spores of Thermoactinomyces vulgaris]. The germination of the spores of Thermoactinomyces vulgaris formed on a complex medium is stimulated by suspending them in solutions containing Mg2+ and Ca2+ ions. The stimulation is not the result of the initiation of the spores in the presence of the ions since the experiments were carried out at a temperature of 20 degrees C at which the initiation did not virtually take place. The ions of Na+ and K+ have almost no effect on the germination of the spores. The fraction of the resting spores of Thermoactinomyces vulgaris depends on the composition of the growth medium, especially on its amino acid composition. The addition of Mg2+ and Ca2+ ions to a minimal synthetic growth medium stimulates the growth of the cultures and decreases the dormancy of the spores. The spores formed on the synthetic medium are less thermostable than the spores formed on the complex medium. Thermostability of the spores increases upon the addition of Mg2+ to the synthetic medium. Spore suspensions obtained on the synthetic medium with Mg2+ or Ca2+ are initiated more completely than spore suspensions obtained on the complex medium.


[Changes in the composition of intracellular lipids and hydrocarbons in Candida tropicalis in the absence of growth]. The fatty acid composition of lipids and the composition of hydrocarbons were studied in Candida tropicalis cultivated on a medium with propionic acid and incubated in the conditions of starvation and on a medium containing glucose-1-6-14C but no nitrogen. Intracellular fatty acids with an odd number of carbon atoms were found to be easily metabolized by yeast cells. The content and composition of intracellular hydrocarbons were very labile and underwent intensive transformation caused by changes in the metabolism of the yeast cell.


[Yeast growth on solid natural oil].

[Yeast growth on solid natural oil]. Two strains of the yeast Candida lipolytica with a specific response to n-alkanes could grow on a medium with paraffins only in the case of contact of the cells with the particles of hydrocarbons. A mixture of paraffins with a solidification point of 35 degrees C contained 41.6% of n-alkanes with the carbon chain from C8 to C36. Assimilation of n-alkanes was studied along with the yeast growth in the course of fermentation. Penetration of the hydrocarbons into the yeast cells and the specificity of the substrates for both yeast strains are discussed.


[Spectrophotometric characteristics of the coccoid forms of actinomycetes]. IR spectra of thw whole cells of the coccoid forms (Mycococcus and Micrococcus) isolated from lithophilous lichen were compared with IR spectra of the collection cultures of Micrococcus and Arthrobacter. Generic spectral characteristics of Mycococcus and Micrococcus are presented. Spectral heterogeneity within the genus Arthrobacter complicates the diagnosis. The cultures of the Mycococcus genus were divided into three groups according to their spectral characteristics. Spectral scans of the studied coccoid forms differ from the scans of the mycelial actinomycetes, and their intensities within the range of 900-1200 cm-1 (lipids) decrease in the series Mycococcus, Arthrobacter, Micrococcus.


[Specific phages used for differentiation of the entomopathogenic bacterium Bacillus thuringiensis]. The sensitivity to specific phages and morphological, physiological, and antigenic properties were compared among several strains of Bacillus thuringiensis isolated from insects inhabiting various geographical zones. All 43 cultures assigned to Bac. thuringiensis var. sotto and 198 among 170 cultures classed as Bac. thuringiensis var. dendrolimus were found to belong to Bac. thuringiensis var. dendrolimus. None of these cultures was resistant to its specific phage. The same was true of 22 studied cultures of Bac. thuringiensis var. galleriae. Only two among studied 45 cultures of Bac. thuringiensis var. thuringiensis were resistant to phages specific for this variety. Therefore, the abundance of variants resistant to specific phages in natural conditions differs among the varieties of Bac. thuringiensis. In most cases, cultures of the same variety of Bac. thuringiensis isolated from various insects inhabiting different geographical zones are identical by their sensitivity to specific phages and by other important characteristics.


[Respiration and dehydrogenase activity of pigmentless variants of Staphylococcus aureus]. Respiration and dehydrogenase activity were studied in four pigmentless mutants of Staphylococcus aureus 209-P. The rate of oxygen uptake from the incubation medium was higher in the mutants than in the parent strain. The rate of respiration and the activity of dehydrogenase in the pigmentless mutants were found to depend on the permeability of the cell membrane for substrates of respiration; carotenoids are presumed to be involved in this permeability.


[Effect of inoculation on nitrogen fixation by chick pea, on its crop and protein content]. Active strains of Rh. cicer were found to increase the crop of chick pea by 25--36%, the content of protein by 2--6%, and the content of total nitrogen in the roots by 1.7--2%. Symbiotic fixation of nitrogen determined by a technique of "inoculation" varies within 40--60% depending on the activity of the strain. No correlation has been established between the effectiveness of the strains of nodule bacteria and the activity of their enzymes--dehydrogenases.


[Effect of IAA on the content of RNA in the cells and isolated nuclei of Aspergillus oryzae]. The content of RNA in mycelium and isolated nuclei of Aspergillus oryzae 3-9-15 was studied after its growth during two days on the modified Capek medium containing 0.01 and 10 mg% of IAA. A direct correlation has been established between the extracellular concentration of IAA and its content in the mycelium and isolated nuclei of the fungus. The stimulating effect of the extracellular IAA on the content of RNA in the isolated nuclei was optimal after one hour of incubation in the Capek medium containing 0.01 or 10 mg% of IAA.


[Assimilation of alpha-ketoglutaric acid by Azotobacter chroococcum]. Labelled alpha-ketoglutaric acid was used to study the inability (complete or partial) of some strains of Azobacter chroococcum to grow on this substrate. This inability is interpreted by the absence, or a lower rate, of induced synthesis of the transport system specific of alpha-ketoglutaric acid.


[Microorganism in the hyphae of mycorrhiza-forming fungus]. A microorganism with the cell wall and cytoplasmic membrane was found when the endotrophic mycorrhiza of pea was studied by electron microscopy. The wall of the microorganism was in a close contact with the cytoplasm of the fungus. No changes were found in the ultrastructure of the fungus and microorganism caused by their interaction.


[Respiration of oligonitrophilic bacteria]. The respiration rate of 25 studied oligonitrophilous strains belonging to various genera and species of bacteria varied within wide limits depending on their taxonomy, conditions of cultivation, substrates, and other factors. No strict correlation was established between the respiration rate and the activity of nitrogen fixation. One of the typical properties of oligonitrophilous bacteria is a high rate of endogeneous respiration --50% and more of the respiration rate during assimilation of exogeneous substrates. The level of oxidative metabolism of oligonitrophilous bacteria was found to be higher on media containing bound nitrogen than on media without nitrogen.


[Facultative methylotroph belonging to the genus Arthrobacter]. A bacterial strain has been isolated and identified, on the basis of its morphological and physiologo-biochemical properties, as Arthrobacter globiformis. The bacterium is a facultative methylotroph and grows not only on media with various organic compounds but also in the presence of methylated amines as a sole source of carbon, nitrogen, and energy. Other C1-substrates were not utilized.


[Directed biosynthesis of proteolytic enzymes in Actinomyces thermovulgaris]. The biosynthesis of proteolytic enzymes in the thermophilic culture of Actinomyces thermovulgaris, strain T-54, was directed by changing the composition of the medium and the temperature of cultivation. A temperature of 40 degrees C is optimal for the growth and production of neutral and alkaline proteases. The maximum activity of acid proteases was found during the growth on a complex medium at 30 degrees C. An increase of temperature to 50 degrees C during the cultivation of the microorganism on a chemically defined medium resulted in its secondary growth and a sharp rise in the activity of alkaline and neutral proteases.


The effect of fetal and placental weight at birth on weight during early childhood. A study of children whose birth weights or placental weights were above the 90th or below the 10th percentile for gestational age indicated that bigness at birth tends to be an innate quality, as the majority of those who were large at birth remained oversized. The small at birth are not all destined to remain diminutive, as the children in this category attained a normal distribution curve for weight during the first year of life. Thus smallness at birth may represent intrauterine nutritional deprivation and be overcome with normal access to calories. The influence of the placenta on infant size is temporary and is modified by extrauterine nutrition. Thus, although there was a direct relationship between birth weight and placental weight, the distribution of weight of children with either large or small placentas was not significantly different from the expected normal distribution at one year of age.


Educational and psychological factors in the management of diabetes in childhood. Thirty-seven diabetic children and their parents were studied with respect to their level of understanding of the nature and management of diabetes as well as their attitude towards, and acceptance of the disease. These were then compared with the adequacy of their management, as evidenced by the frequency of hospital readmissions. In those families in which the child's disease was poorly managed, the parents were found to know significantly less about diabetes than those parents whose children were well managed. Similarly, those families in which the child's management was poor, were found to have a high level of family maladjustment, while the parents had a poor attitude towards and were unable to accept their child and his disease. It was also found taht diabetic children as a whole have a high level of social maladjustment but do not feel they are greatly "different" from their fellows.


Smoking and pregnancy.

Smoking and pregnancy. Smoking is associated with decreased fertility in both males and females, an increased abortion rate, lowered birth weight, an increased still birth rate and probably an increased neonatal death rate. There is also a reduced incidence of maternal hypertension (although the babies are at even greater risk), an increased incidence of ante-partum haemorrhage, impaired brain development and possible teratogenic effects. These effects can be reversed if the mother gives up smoking in pregnancy.


The influence of seat belt wearing on the incidence of severe head injury. A retrospective follow-up of patients admitted to hospital with a diagnosis of head injury in two sample years, before and after the introduction of legislation requiring the use of seat belts, has been undertaken. This shows a marked reduction in the incidence of severe head injury following the introduction of this legislation.


Mite populations in sydney household bedding with particular reference to nursery sheepskins. Samples of dust were collected from three articles of household bedding in twenty-two Sydney homes during a six-week period beginning in mid December, 1973. Mites, sometimes in large numbers, were found in all homes. The mean number of mites recovered from nursery sheepskins (all woollen) was thirteen times as high as the mean number from other forms of adult or infant bedding sampled. The high mean number in sheepskins is the result of massively high populations in seven of the eighteen skins sampled. Hospital sheepskins were almost almost uniformly mite free. Far fewer mites were collected from cot mattresses which were either vinyl topped or covered with a plastic coverslip than were collected from a cot mattress with a cotton top alone.


[Hypoparathyroidismus following L-asparaginase and vaccinia virus infection. Effect of hypocalcemia on phagocytosis and the function of lymphocytes]. Rabbits, treated with injections of 4000 IU of L-Asparaginase, develop the clinical and chemical signs of hypoparathyroidism. A simultaneous vaccination with vaccinia virus (strain "Elstree") markedly increase the tetanic symptoms ("conditioned deficiency"). L-Asparaginase may influence the cellular immunity by hypocalcemia. Two mechanisms are discussed: 1. the suppression of the phagocytosis, recognizable by the absence of signs for vaccinal allergy by deficiency of macrophages in the intradermal test with inactivated small-pox vaccine. 2. the inhibition of the PHA-induced lymphocyte transformation caused by deficiency of  calcium ions.


[Isolation of influenza virus "A/Hong Kong/1/68 (H3N2)" from liquor cerebrospinalis of patients with CNS involvement (author's transl)]. Liquor cerebrospinalis of eight patients with central  nervous symptoms were tested for influenza virus during the influenza virus epidemic 1971/72. In three of these cases influenza virus (A/Hong Kong/1/68 (H3N2) was isolated from spinal fluid in the embryonated hen egg. These patients showed after influenza like prodromi meningo-encephalitis, encephalitis or paranoid psychosis. Possible pathomechanisms are discussed.


[Evaluation of helminth carrier rates among foreign workers (author's transl)]. The evaluated helminth carrier rate among foreign workers give rise to many problems under socio-economic, hygienic and occupational aspects. The evaluation of helminth infestation is connected with considerable uncertainty. Based on the author's examinations these problems are critically investigated from the point of view of both, the employer and the employee. It is shown in tables that in the Institute of Hygiene and Microbiology of Würzburg during 1973/1974 497/702 respectively faecal examinations were performed among German and foreign employees and workers. No difference was noted in the overall positive rates in both groups. But there were distinct differences in the species of helminths noted: Among the foreign workers mainly Trichuris trichiura, Ascaris lumbricoides and Enterobius vermicularis were noted while among Germans Taenia saginata prevailed. Noteworthy is the fact, that workers from Turkey and Yugoslavia have occasionally three and more species of helminths and pathogenic protozoa in a single specimen. Since the helminth species found are not transmitted from man to man and since usually the circumstances do not permit a transmission via food, such carriers of helminth don't represent a direct danger for man or the contamination of foofdstuff. For hygienic reasons however helminth carriers may not be acceptable in certain occupations. In case of clinical symptoms the treatment of such patients is required for medical reasons. In spite of frequent absence of clinical signs the consequent liberation of the carriers from their intestinal worms and the sanitation of their personal environment should not be neglected.


Clinical and serologic effects of Alice strain live attenuated influenza A (H3N2) virus vaccine in an adult population. Alice strain live attenuated influenza A (H3N2) virus was evaluated in prison volunteers. By random double blind allocation, 94 volunteers received Alice strain vaccine (AS) intranasally and 97 received placebo. The vaccine was well tolerated, and there was no serious morbidity. The number, type, duration, and severity of symptoms was not significantly different between the vaccine and placebo groups. Seventy-five per cent of vaccines with initial HAI titers less than or equal to 1:8 had 4 fold or greater titer responses on day 30. Placebo recipients experienced no titer changes. The GMT among vaccinees increased from 23.5 prior to vaccination 59.7 30 days later. Surveillance activities failed to document influenza A (H3N2) infection in the volunteer population during a 6 month follow-up period. Additional studies on the protective effects of the vaccine are required before efficacy can be determined.


Permanent canine kidney (MDCK) cells for isolation and plaque assay of influenza B viruses. A wide range of influenza B virus strains with various passage histories uniformly formed well-defined clear plaques with high efficiency in cultures of an established line of canine kidney cells (MDCK). PFU titers of the viruses assayed in MDCK exceeded the titers assayed in ovo. With recently isolated strains such as B/Hong Kong/5/72 and Gifu/2/73, the PFU/EID50 ratios were as high as 100 to 400. MDCK cells have been successfully employed for primary isolation of influenza B viruses from throat washings of patients by direct plaquing.


Plaque assay and primary isolation of influenza A viruses in an established line of canine kidney cells (MDCK) in the presence of trypsin. A wide variety of influenza A viruses, comprising human, equine, porcine, and avian strains, grew productively in an established line of canine kidney cells (MDCK) under an overlay medium containing trypsin, and formed well-defined plaques regardless of their prior passage history. Plaquing efficiency was comparable to the efficiency of infection in fertile eggs via allantoic route. MDCK cells have also been successfully employed for the primary isolation of influenza A virus from throat washings of patients. Parallel titration of several clinical specimens showed that the inoculation into MDCK cells followed by incubation in the presence of trypsin was an isolation procedure as sensitive as the amniotic inoculation into fertile eggs.


Relationship between measles virus-specific antibody activities and oligoclonal IgG in the central nervous system of patients with subacute sclerosing panencephalitis and multiple sclerosis. The association between oligoclonal IgG and measles virus antibodies present in cerebrospinal fluid samples or extracts of brain materials from 9 patients with subacute sclerosing panencephalitis was studied after electrophoretic separation. In all samples there was a good correlation between presence of bands of IgG and occurrence of specific antibody activities. The dominating band of oligoclonal IgG appeared in all cases to represent antibodies against the nucleocapsid antigen. Bands of oligoclonal IgG with a certain antibody activity displayed a tendency to occupy a preferential position in the electropherogram. Antibodies against the hemolysin and the nucleocapsids had a relatively more cathodic position than antibodies against the hemagglutinin. A clear correlation between bands of oligoclonal IgG and measles virus-specific antibody activity was not found in tests with materials from 4 patients with multiple sclerosis and 1 patient with myelopathy of unknown cause. However, a heterogeneous distribution of different antibody activities in separated material suggested that some electrophoretically restricted IgG proteins might carry these activities.


Measurement of partial pressure of gases in liquids by mass spectrometry. The experimental setup of mass spectrometric determination of gas contents in liquids has been modified for continuous and discontinuous measurement of partial pressure of gases in liquids. The inlet system consists of a stainless steel capillary with slits covered by a silicone rubber membrane. Several gases can be measured simultaneously under static conditions and in flowing liquids. The measurement and calibration procedure is described. Results of the analysis of the test criteria, reproducibility, detection limit, response time, and depletion are presented. The difficulties in discontinuous measurement of oxygen in blood are explained by the complex permeation-diffusion process at the membrane and the form of the dissociation curve. With regard to solubility, physically dissolved gases can be determined without problems down to tensions of about 0.01 mm Hg. Continuous measurement of oxygen and carbon dioxide partial pressure in liquids, including blood, is possible with the described system.


Water-vapor-independent inlet system for a respiratory mass spectrometer: application to experiments with a human centrifuge. When using a two-stage inlet system in mass spectrometric analysis of permanent gases, changes of water-vapor partial pressure from inspiration to expiration considerably impede the measurements. With this type of gas inlet system, use of a mass spectrometer for measurements on a human centrifuge is rather limited. Introduction of a water-vapor - independent three-stage inlet system permits quantitative analysis of gas mixtures even if the water vapor pressure varies quickly with time. The expiratory oxygen and carbon dioxide partial pressure curves should exemplify that even under extreme acceleration conditions the three-stage system permits simultaneous and continuous mass spectrometric analysis of respiratory gases, with satisfactory response time and a simple experimental arrangement. The method described thus opens up new experimental possibilities for the investigation or respiratory gas exchange phenomena under acceleration conditions.


Mechanical aspect of the heart sound emission. The present paper deals with a physical study of the relation between the phonocardiogram and left ventricular pressure (LVP) fluctuations. Fourier analysis comparison of the two signals-simultaneously recorded either on pathologic human hearts or during experiments on dogs-does not point out an obvious relation between the phonocardiogram and a linear combination of the first pressure derivatives.-A mechanical model of the heart enabling the description of the sound emission mechanism provides a qualitative relation between the phonocardiogram and LVP fluctuations: the acceleration of the thoracic area is equal to the product of LVP by a time function depending on the mechanical properties of the muscle. - A theoretical thoracic acceleration obtained by transformation of the experimental LVP is compared with the experimental phonocardiogram through linear filtering analysis. The theoretical signal is in good agreement with the experimental one.


Technological progress in pacemaker design: hermetic sealing. Clinical statistics covering the life of pacemakers powered by mercury batteries show that an average life of 3 years has not yet been obtained. Strangely, the life does not seem to depend on the current consumed by the pacemaker, whether of the demand or asynchronous type. A study of the behavior of 229 mercury batteries discharged in a dry atmosphere showed that 92% of the batteries were still functioning after 54-57 months. It is deduced that pacemaker life is shortened by the infiltration of moisture into the batteries when molded in an epoxy. - A technology for the hermetic encapsulation of a pacemaker is described. This technology is applied to both mercury and lithium batteries. The results obtained with 5835 instruments over periods of up to 36 months.


Intragenic recombination at the white locus of Drosophila hydei. A fine-structure analysis of the white locus in Drosophila hydei was carried out by means of allele recombination. Four mutants, derived from wild type, mapped at three subloci. These are possibly homologous to the main subloci 2, 3, and 4 of D. melanogaster. Three secondary mutants, derived from the primary wiv allele, were located in the proximal part of the gene. One of them appeared as a homoallele of the original wiv, whereas the remaining two are better explained either as double mutants or as mutants which facilitate irregular exchange. Intragenic recombination at the white locus seems to be more frequent in D. hydei than in D. melanogaster. The comparatively high incidence is probably a general characteristic, common to intragenic and intergenic recombination in D. hydei.


The starting point and direction of rolling-circle replicative intermediates of coliphage lambda DNA. Intermediates of lambda DNA replication in the second half of the latent period after phage lambda infection were isolated and investigated in the electron microscope by denaturation mapping. The isolated replicative forms (RF) are predominantly single branched circular DNA. The starting points of replication in these lariat molecules located at the same region as the first round lambda DNA replication. About 60% of the RF replicate from left to right and the other 40% replicate in the reverse direction. The free ends of the tails are located at many sites on the lambda genome. Replicating circles with a linear DNA tail longer than one unit length of lambda genome represent about 30% of the replicating molecules. These long linear tails (concatemers) produced by the rolling-circle (Gilbert and Dressler, 1968; Eisen et al., 1968; Skalka et al., 1972; Takahashi, 1974) are one of the best candidates for a precursor DNA of progeny phage.


Genetic map of the beginning of the rIIB cistron of bacteriophage T4. In this report the herefore uncharacterized mutants at the beginning of the rIIB cistron of bacteriophage T4 have been connected to the main part of the map and have been shown not to be in any way unusual. The temperature sensitive mutant HD263 appears to be the earliest mutant in the cistron.


Nucleic acid metabolism in yeast. I. Inhibition of RNA and DNA synthesis by high concentrations of exogenous deoxythymidine 5'-monophosphate in 5'-dTMP low requiring strains. The three haploid yeast strains T2tmpl1-3, T2tmp1-1, and T6tmp1-51 auxotrophic for 5'-dTMP differ in their requirement for thymidylate: 72, 16, and 3 mug 5'-dTMP/ml will restore optimal growth, respectively. Thymidylate low requirement in strain T2tmp1-1 and T6tmp1-51 is termed tlrA and tlrC, respectively. When the growth medium is made 5 x 10(-4) M for 5'-dTMP only strain T6tmp1-51 is severely inhibited in RNA and DNA synthesis. This inhibition is reversible after removal of excessive 5'-dTMP. The inhibitory characteristic is in marked contrast to "thymineless death" due to the lack of 5'-dTMP in strain T6tmp1-51 where only DNA synthesis stops while RNA synthesis continues. The inhibitory effect of 5 x 10(-4) M 5'-dTMP is not due to the 5'-dTMP auxotrophy but to the thymidylate low requiring character (tlrC) in strain T6tmp1-51. The arrest of RNA and DNA synthesis by high concentrations of exogenous 5'-dTMP suggests a regulatory role of either the mono- or triphosphate on nucleoside or nucleotide biosynthesis in yeast.


Three mRNA populations differing in turnover and processing in mouse liver. Using kinetics of approach to steady state labeling, we have found that liver poly(A)+ mRNAs fall into three populations, differing in stability and probably in processing, as reflected in their dissimilar delays in reaching polyribosomes and turnover times. There are mRNA-1 (delay 10 min, half-life 1 hr); mRNA-2(delay 3 hr, half-life 2 hr); and mRNA-3 (delay 40 min, half-life 2.6 hr). The first two species function on free polyribosomes while the third one is operating on bound polyribosomes. The populations listed contribute 10,20 and 70%, respectively, to the total steady state labeled poly (A)+ mRNAs.


Modified 5'-termini in small nuclear RNAs of mouse myeloma cells. Nuclei of MPC 11 mouse myeloma cells contain several species of small RNAs related to those found in other mammalian cells. These include U1 RNA, about 190 nucleotides in length and U2 RNA, about 170 nucleotides long. The 5'-termini of 32P-labelled U1 and U2 RNAs have been investigated by a fingerprinting technique involving digestion with T2-ribonuclease. The RNAs were found to have modified 5'-terminal structures of the form m3G(5')ppp (5')AmpUmpAp for U1 RNA and m3G(5')ppp(5')AmpUmpCmpCp for U2 RNA, where m3G is N2, N27-trimethyl guanosine and Am and Um are 2'-O-methyl nucleosides. These 5'-terminal sequences are the same as those proposed for rat hepatoma U1 and U2 RNAs (Ro-Choi et al., Fed. Proc. 33, 1548, 1974) but with triphosphate rather than diphosphate links.


The kinetics of complex formation of tryptophan containing proteins with pyridinium salts. Upon preincubation with urea, various 3- or 4-substituted N-methylpyridinium salts form charge-transfer complexes with tryptophan containing proteins such as, L-chymotrypsin and lysozyme. The complexes were studied by using the difference spectrophotometric technique. The fluorescence examination showed that tryptophyl residues in protein molecules are engaged in the complex formation process. The complex formation reactions proceed at a considerable rate. The stopped-flow method was used to determine the pseudo first order rate constants. A linear dependence of the pseudo first order rate constants with the donor concentration was found. The second order rate constants were obtained by dividing the mean value of the pseudo first order rate constants by the initial donor concentration for each run. The linear dependence of second order rate constants with the electron affinity of the acceptors can serve as a criterion for the formation of charge-transfer complexes.


Structure of rough, smooth, stripped and reconstituted rough membranes derived from rat liver as visualized by the freeze fracture technique. The structure of purified fractions of rough, smooth, stripped rough and reconstituted rough membranes have been investigated by the freeze etching technique. Preparations of rough and reconstituted rough membranes, active in protein synthesis, show vesicles whose outer surface is covered with ribosome-like particles. The inner surface of these vesicles contains also numerous particles of the same size. The particles located on the outer surface are largely absent in the stripped rough membrane preparations which, however, retain the particles located on the inner face. Particles were not seen either on the outer nor on the inner face of the smooth membranes. The possibility is considered that the particles located on the inner face are specific to the rough membranes and might play a role in the specific binding of ribosomes to the membranes.


The molecular weights of yeast ribosomal precursor RNAs. The molecular weights of the predominant rRNA precursors as well as those of 26-S and 17-S mature rRNA from Saccharomyces carlsbergensis were determined by polyacrylamide gel electrophoresis in the presence of formamide. Mature 26-S + 5.8-S rRNA was found to have a molecular weight of 1.24 X 10(6) while their immediate precursor, 29-S RNA, had a molecular weight of 1.52 X 10(6). Values of 0.70 X 10(6) and 0.82 X 10(6) were obtained  for the molecular weights of mature 17-S rRNA and its 18-S precursor. Finally the 37-S precursor, common to both 29-S and 18-S RNA, was found to have a molecular weight of 2.80 X 10(6). Each precursor rRNA, therefore, contains extra sequences not found at the next stage of maturation.


A simple method for the purification of reticulocyte globin messenger ribonucleic acid. A relatively simple and inexpensive method has been developed for the preparation of highly purified rabbit reticulocyte globin mRNA. After phenol extraction, polysomal RNA was chromatographed on Sigmacell type 38 cellulose and Sepharose 4B. The resulting mRNA preparation has a purity in excess of 90%. No selective loss of either alpha or beta globin mRNA is observed.


[The types of virus-specific structures in cells of human origin producing oncornaviruses]. In the cell cytoplasm of human tissue cultures Detroit-6 and AO which produce B type oncorna-virus, two types of virus-specific structures were revealed. Structures of type I were aggregated fibrils of 3 and 6 nm diametre. Structures of type II were nucleoids of A-particles of 70-80 nm diametre. They were rather well separated from cell components by centrifugation sucrose density gradient and repeated centrifugation in the sucrose concentration gradient. Fibrils were found in the density regions of the equilibrium gradient of 1.26 and 1.19 g/cm3, whereas A-particles were detected in the sones of the density of 1.29 and 1.23-124 g/cm3. Their sedimentation coefficients in the sucrose concentration gradients were about 150S and 250S, respectively. From both structure types similar RNA classes were extracted sedimenting in 60S, 45S and 35S regions (sucrose concentration gradient). In addition, 20S RNA was found within the 150S structures. Both structures sa. However, hydridization degree of RNA isolated from both structures with DNA synthesized enzymatically on extracellular various (DNA I) and A-particles (DNA II) was different. With DNA-I, 50-80% of RNA isolated from the type I structures and less than 20% of RNA extracted from the type II structures were hybridized. At the same time, strictly opposite situation (50-80% of RNA II and 20% of RNA I) was observed for DNA-II. These data show lack of genetic connection between these types of cytoplasmic structures and possible role of type I structures in reproduction of oncorna-virus type B.


[Calculation of DNA molecule packing in crystals by the method of atom-atom potentials I. B-form of DNA]. The van-der-Waals interaction of DNA molecules in the B-form has been studied by the method of atom-atom potentials. This study was carried out to clarify to what degree does this interaction determinate packing of DNA molecules in a crystal lattice. Interaction energy of two parallel molecules has been calculated as a function of 4 parameters (interaxial distance, axial shift, screw rotation of molecules). Energy as a function of these parameters is shown to have two minima, one of them exactly corresponding to mutual arrangement of DNA molecules in the lattice determined from X-ray data.


[Kinetic behavior of slowly equilibrating association-dissociation enzyme systems]. The shape of the plots of product accumulation versus time (t) has been analysed for slowly equilibrating association-dissociation enzyme systems of the types 2p in equilibrium P (P is enzyme oligomer which is able to dissociate reversibly forming two identical halves p) and M in equilibrium M2 in equilibrium M2 in equilibrium... (M is monomer which has two association sites overlapping with active sites). It is assumed that the rate of equilibration between oligomeric forms is comparable with the rate of over-all enzymatic reaction and that substrate-oligomer complexes are in rapid equilibrium with free components. It has been shown that characteristic feature of kinetic behavior of slowly equilibrating association-dissociation enzyme systems is that the value of tau depends on enzyme concentration (tau is the intercept on t-axis for linear asymptota of the curve of product concentration versus time at t leads to infinity).


[Effect of DEAE-dextran upon the interaction of polynucleotides in poly (l+c) double complex]. It has been shown that the formation of poly(I+C) double complex is accompanied by appearance of the 244 nm CD band which is absent from the spectrum of the initial components. The amplitude of this CD band is maximum upon equimolar ratio of components. When one mixes the complementary polynucleotides bound to DEAE-dextran (D-d) double comples is not formed. CD spectrum of poly (I+C) double complex is changed considerably upon addition of D-d: CD increases when P/N ratio is 10:1, decreases at P/N 1:1 and comes back to the initial spectrum at P/N 1:5. Thermal dissociation of poly(I+C) when the anionic component was in surplus was similar to poly(I+C) alone (Tm equals 67 degrees) when the polydextran was in excess; the thermal dissociation was lower (Tm equals 43 degrees) than that of poly (I+C). It is discussed the possible mechanism of the D-d and poly (I+C) interaction.


[Secondary structure of DNA from T4 and T6 phages]. The secondary structure of NaDNA from E. coli T4 and T6 phages has been studied by the X-ray diffraction method. Molecules of these DNAs as well as T2 phage DNA molecules contain hydroxymethylcytosine glucosylated at different position instead of cytosine. At high relative humidity these DNAs are shown to exist in B-conformaion. As humidity decreases the transformation into T=conformation takes place in the T4 phage DNA whereas in the T6 phage DNA changes of secondary structure similar to B-T transformation occur which do not result however in the appearance of all the characteristics of the T-conformation.


[Fluorescence of myosin and its subunits in concentrated salt solutions]. The parameters of fluorescence spectra of myosin and its subunits in Tris-HCl-buffer (pH 7.2) were studied. Analysis of the experimental results of myosin fluorescence quenching with I-ions and the quantum yield of the fluorescence at the excitation wavelength 296 nm shows that the greater part of the tryptophan residues (21 out of 28) is located in the hydrophylic environment. Concentrated solutions of NaCl and KCl do not affect myosin fluorescence, while LiCl, which changes the quaternary structure of the protein, brings about a change in the parameters of the myosin fluorescence spectra. This may be linked with structural changes accompanying the dissociation of the ligh subunits of myosin in the presence of LiCl.


[Migration of electron excitation energy in mixed associates of chlorophyll and its derivatives]. The intracomplex migration is investigated of electron excitation energy between molecules which are a part of a mixed associate. Weakly fluorescent and nonfluorescent associates of chlorophyll and its analogues as well as of bacteriochlorophyll and neoxanthine have been used as donors and acceptors. The migration of excitation energy with variation of quantum yield of donor emission from 5-10(-3) to less than or equal to 10(-4) and also with very weak overlapping of luminescence and absorption spectra for the pair D leads to A is experimentally discovered by luminescence excitation spectra of mixed pigment aggregates. A specific disturbing action of Pd and Cu ions on chlorophyll a luminescence with formation of mixed complexes of chlorophyll with Pd-pheophytin a and Cu-pheophytin b is observed. The presence of Pd and Cu ions in the structure of the mixed complexes gives rise to a considerable reduction of chlorophyll apparently due to increasing intersystem crossing probability in the chlorophyll molecule. The probability of intracomplex energy migration in systems under investigation amounts to approximately 10(12) sec-1 according to the obtained estimations. The probable mechanism of energy migration in mixed associates is discussed. The obtained results may be used for elucidation of a possible role of the mixed aggregates and effective intracomplex migration of excitation energy in photosynthetic apparatus of green plants.


[Theoretical study of the hypochromic effect in polynucleotides]. The first UV-absorption band hypochromicity of poly(dA)-poly(dT), poly(dG)-poly(dC), poly(dA), poly(dT), poly(dG), poly(dC), is calculated with the help of the perturbation theory. The wave functions of the bases are computed by Pariser--Parr--Pople's method taking into account all the singly excited configurations. The results obtained show a good correlation between the theoretical and experimental values of hypochromicity. A considerable influence of the vaccum electron transitions on the hypochromicity of polynucleotides is revealed. The origin of the hypochromic effect in the double-stranded polynucleotides is investigated. It is shown that intrastrand interactions between the bases make the main contribution to hypochromicity (60-76%), while the contribution of the Watson-Crick pairs is small (2-12%). The essential part of hypochromicity (22-28%) is due to the interstrand interactions between the bases which are not coupled by hydrogen bonds. The discussion of the experimental data shows that the present theoretical investigation could serve as a basis for correct treatment of experimental results.


[Some properties of 1 P+f bacteriophage for Bacillus brevis var. G.-B and its nucleic acid]. The 1 P+f phage, a virulent mutant of the moderate P+ phage for Bac. brevis var. G.-B., consists of a hexagonal head (90x90 nm) and a long non-contractile tail (340 nm). This phage is characterized by a relatively long latent period (90-110 min) and a low yield (40-50 particles per cell). The 1P+f phage is quite stable at pH values from 1 to 11, insensitive to osmotic shock, treatment with chloroform and acridine orange. The sensitivity of the phage to thermal treatment and UV-radiation has been studied. The nucleic acid of the P+f phage is double-stranded DNA of AT-type (GC equals 34.5 mole %) which contains 5-methylcytosine (0.18 mole %) and N6-methyladenine (0.32 mole%). The level of methylation of cytosine and adenine residues in DNA of the 1 P+f phage does not depend on the host studied (Bac. brevis, P- and S variants). The specificity of methylation of cytosine residues in the S and P- cells appears to be the same. DNA of the 1 P+f phage strongly differs from DNA of the host in nucleotide composition (GC equals 45.7 mole %). Nevertheless, phage DNA is very similar to DNA from Bac. subtilis in the character of pyrimidine distribution (the amount of different pyrimidine isopliths). This may testify to a somewhat common character of the nucleotide sequence organization in DNA of the phage and its host.


[A code governing specific binding of regulatory proteins to DNA and structure of stereospecific sites of regulatory proteins]. A model is proposed for the structure of stereospecific sites in regulatory proteins. On its basis a possible code is suggested that governs the binding of regulatory proteins at specific control sites on DNA. Stereospecific sites of regulatory proteins are assumed to contain pairs of antiparallel polypeptide chain segments which form a right-hand twisted antiparallel beta-sheet, with single-stranded regions at the ends of the beta-structure. The model predicts that binding reaction between a regulatory protein and double-helical DNA is a cooperative phenomenon and is accompanied by significant structural alteration at the stereospecific site of the protein. Half of hydrogen bonds normally existing in beta-structure are broken upon complex formation with DNA and a new set of hydrogen bonds is formed between polypeptide amide groups and DNA base pairs. In a stereospecific site, one chain (t-chain) is attached through hydrogen bonds to the carbonyl oxygens of pyramides and N3 adenines lying in one DNA strand, while the second polypeptide chain (g chain) is hydrogen bonded to the 2-amino groups of guanine residues lying in the opposite DNA strand. The amide groups serve as specific reaction sites being hydrogen bond acceptors in g-chain and hydrogen bond donors in t-chain. The single-stranded portions of t- and g-chains lying in neighbouring subunits of regulatory protein interact with each other forming deformed beta-sheets. The recognition of regulatory sequences by proteins is based on the structural complementarity between stereospecific sites of regulatory proteins and base pairs sequences at the control sites. An essential feature of these sequences is the asymmetrical distribution of guanine residues between the two DNA strands. The code predicts that there are six fundamental amino acid residues (serine, threonine, asparagine, histidine, glutamine and cysteine) whose sequence in stereospecific site determines the base pair sequence to which a given regulatory protein would bind preferentially. The code states a correspondence between four amino acid residues at the stereospecific site of regulatory protein with the two residues being in t- and g-segments, respectively, and AT(GC) base pair at the control site. It is thus possible to determine which amino acid residues in the repressor and which base pairs in the operator DNA are involved in specific interactions with each other, as exemplified by lac repressor binding to lac operator.


[Application of x-ray analysis for the study of the orientation in DNP films]. A planar texture in dried film samples of DNP was found by X-ray study. Axes of DNA macromolecules are located in the film plane and the 77 A reflection is directed along this axis. Periodic structures corresponding to 55 and 34 A are packed parallel to the film plane. The results obtained do not contradict with a supercoil DNP model, however they all allow other possible packing models of DNP molecules, in particular, histone layers alternating with DNA layers in oriented films.


[A compact form of DNA in solution. III. Influence of the ion composition of the solution on the compactization process of double-stranded DNA in the presence of peg]. The data showing the features of the DNA compactization process in PEG-containing solutions of chlorides of different alkaline metals (LiCl, KCl, RbCl and CsCl) and an ammonium salt (CH3-(CH2)17-N-(CH3)3Br) are presented. The data indicate that the formation of a compact form of the double-stranded DNA in PEG-containing water-salt solutions depends not only on the PEG concentration and ionic strength but on tha cation nature as well. The compactization occurs most easily in the presence of Na+-ions. This indicates a specific character of interaction between Na+-ions and DNA phosphate groups which may be due to an optimum structural fit between the hydrated Na+-ions and orientation of the phosphate groups in the DNA molecule. The nature of forces involved in the processes of the intramolecular compactization and intermolecular aggregation of double-stranded DNA molecules in water-salt solution is discussed. The difference between the effect of Na+ and that of K+-ions on the compactization process at the ionic strengths close to physiological values makes it possible to suggest that the changes of the tertiary structure of double-stranded DNA which accompany its function in vivo may take place under conditions of a decreased water activity at the expense of relatively slight changes in ion composition of the water surrounding DNA.


[Interaction of chromatin non-histone proteins with homologous and heterologous DNA]. The interaction of different preparations of chromatin non-histone proteins (NHP) isolated from rat liver and thymus with homologous and heterologous DNA was studied by a membrane filter technique. All the NHP preparations studied form complexes with DNA in 0.02 tris-HCl (pH 7.5)--3 mM MgCl2. Denatured DNA binds NHP more effectively than native NDA. The largest part of NHP which interacts with DNA is bound to the latter non-specifically. A small part of NHP interacts specifically with homologous native DNA in 5 M urea. Specific binding of NHP to denaturate DNA is shown both in the presence of urea and in its absence. The data obtained are discussed in the light of a possible role of NHP in the specific regulation of transcription process.


[Studies on DNA bound to histones in chromatin]. Regions of DNA protected by histones against the action of DNAse 1 in the chromatin were isolated. Such DNA fragments ("subhistones" DNA) have 80% double helix structure, their nucleotide composition is close to that of total DNA, and their sedimentation constant is within the range of 2-2.7S for completely denatured molecules. Kinetics of renaturation of "subhistone" DNA was studied: within a wide range of Cot values, renaturation curves of total and "subhistone" DNA are almost identical. According to the data on hybridization with nuclear d-RNA, "subhistone" DNA is transcribed in the cell. The data obtained witness for uniform character of distribution of histones along the DNA chain in the chromatin. DNA sites which are active in RNA synthesis seem to be bound to histones as well as the non-active ones. No significant difference was found in the hybridization of "subhistone" DNA from rat liver and thymus with ibver nuclear RNA.


[The secondary structure of nucleotidyl-(5' bound to N)-amino acids containing different heterocyclic bases and amino acids]. Nucleotidyl-(5' leads to N)-amino acids containing different heterocycle bases: adenine, guanine, hypoxanthine, cytosine, uracyl, and aromatic amino acids: phenylalanine, tyrosine and tryptophan, have been investigated by proton magnetic resonance and circular dichroism. For all the compounds studied folded conformation have been shown stabilized by hydrophobic interaction in aqueous solution. The comparison of the results of the studied nucleotidyl-(5' leads to N)-amino acids unable us to build four secondary structure types in these very compounds. Phenylalanine and tyrosine derivatives of purine nucleotides can be regarded as the first type, tryptophan derivatives of purine nucleotides as the second type, phenylalanine and tyrosine derivatives of pyrimidine nucleotides as the third type and tryptophan derivatives of pyrimidine nucleotides as the fourth type. For each group of these compounds conformational models have been built. In all these compounds the anti-conformation has been proved to exist.


[Analysis of the structure of DNA cistrons coding proteins with known sequences]. Proceeding from the amino acid sequence of a number of proteins, with the help of a special computer program we have determined the frequency of pyrimidine isopliths of different length, the degree of clustering and the degree of asymmetry of complementary chains of the corresponding DNA cistrons, as well as the range of variation of these parametres which depends on the code degeneracy. The degree of asymmetry of the chains of DNA cistrons (H/L), calculated for 255 proteins of a known composition, may vary from 0.7 to 1.8. For 90% of these proteins the mean Py/Pu ratio in the coding chain of DNA is above 1. The conclusion has been made that the majority of amino acids contained in the proteins is coded for by purine triplets. It was found that the distribution of pyrimidine isopliths between DNA cistrons coding for different proteins is other than random and has a "DNA-like" character. The degree of clustering of pyrimidines (beta) in cistrons of different proteins may vary from 6.0 to 14.3. The cistrons of some proteins were found to contain long lyrimidine fragments with about 24 residues. A positive correlation (r2 = 0.74) was found to exist between the degree of clustering of pyrimidines and the degree of asymmetry of the chains corresponding to different proteins of DNA cistrons.


[The role of local hydrogen bonds in formation of irregular regions of globular protein polypeptide chains]. An assumption is made on the substantial role of local hydrogen bonds in formation of irregular regions of globular protein polypeptide chains. The statistics of the amino acid composition of irregular regions is examined from this point of view. A statistical analysis of side group-backbone hydrogen bonds is carried out for three proteins: alpha-chy-motrypsin, lysozyme and myoglobin. It is shown that short side groups participate in formation of local hydrogen bonds more often than long ones. Conformations of amino acid residues in the first and the last positions are studied in beta-bends of 9 proteins. It is shown that over 70% of these residues are in conformations corresponding to the formation of local hydrogen bonds of three types: backbone-backbone, side groupbackbone, backbone-water molecule-backbone. Thus, the participation of the cooperative hydrogen-bonding network in stabilization of beta-bends is demonstrated.


[A study of ratios between histone fractions]. The amount of individual fractions in the whole histone isolated from the blood of hen, frog (Rana ridibunda), bream (Abramis brama), from rat thymus and from the locust (Schistocerca gregaris) was studied quantitatively. It is shown that the ratios between fractions F2a1, F2b, F2a2 and F3 are fixed. The share of each fraction in the sum of fractions F2a1, F2b, F2a2, F3 was found to be approximately 22.5, 30.5, 21.0 and 26.0 per cent, respectively. The share of the fraction F1 can variate within a rather wide range.


[Theoretical conformational analysis of methylamide N-acetyl-L-arginine]. The spatial structure of methylamide N-acetyl-L-argine was studied taking into account the non-valent and electrostati interactions, the torsion energy, and the distorsion of valency angles. Calculation of the favourable conformations of the molecule was carried out with the use of all the combinations of angles phi, psi, chi1 divided by chi4 as an intital approximation. These correspond to the low energy forms of the main chain and to the minima of the torsion potentials of the side chain. Conformational possibilities of arginine and lysine were compared. The calculated stable conformation of N-acetyl-L-arginine-methylamide are compared with the geometry of arginine residues in the proteins with known structure.


[Effect of low-molecular amines on DNA conformation and stability of the double helix]. Interaction of low-molecular amines (cystamine, cysteamine, cystaphose, asparagine, beta-alanine) with DNA was studied. The amines change the positive circular dichroism (CD) band of DNA as well as temperature and range width of melting. Effect of amines on DNA depends on ionic strength of the solvent, concentration and structure of the ligand. Monamines cause destabilization of DNA double helix followed by stabilization as ligand concentration increases. At concentrations stabilizing the double helix DNA conformation undergoes transition from the B- to C-form. The results obtained enable to relate the stabilizing effect of low-molecular amines and conformational B leads to C-transition to the non-specific interaction of ligand amino groups with DNA phosphates, and the destabilizing effect of monoamines of low concentrations to their interaction with bases, mainly in the denaturated sites of DNA. It is proposed that a stronger effectiveness of amines as compared to monovalent metals in the conformational shift of DNA towards the C-form is due to the additional effect of disturbance of hydrophobic interactions in DNA double helix.


[The surface layer of the protein globule. Hydration of the alpha-chymotrypsin molecule]. The surface of the alpha-chymotrypsin globule is investigated using a three-dimensional model of the molecule, constructed on the basis of X-ray data by sectioning the space of the protein globule in cubic elements with a step of 3 A. The surface layer contains about 55% of the overall globule volume. The atomic density of so defined surface was found to be approximately equal to that in the inner part of the globule. Topographical maps of the alpha-chymotrypsin surface were drawn and an analysis of the distribution of polar and unpolar atoms and groups on the surface and in the inner part of the globule was carried out. Some conclusions drawn from the atomic density, energetic and structural heterogeneity of the surface and concerning the conformational integrity and functional activity of alpha-chymotrypsin molecule are presented. Some aspects of the protein hydration problem are discussed and a structural model of the alpha-chymotrypsin hydratation shell is proposed, the main features of which are amorphism and the lack of long-range effect on the structure of water around the hydrated protein globule.


Trisomy and triploidy induced by X-irradiation of mouse spermatocytes. Analysis of second meiotic metaphase divisions in control and irradiated male mice shows that while the spontaneous rates of autosomal and sex chromosomal anaphase I non-disjunction are extremely low, they can be enhanced by X ray treatment of prophase spermatocytes. Irradiation at pre-leptotene results in a higher rate of anaphase I non-disjunction than does irradiation at pachytene. Early spermatogonia are relatively insensitive. Experiments to detect trisomic progeny among the F1 foetal offspring of male mice mated during weeks 5 and 6 following irradiation (sampling of irradiated early spermatocytes and late spermatogonia) showed that none were present. Possible explanations for this are considered. Two triploid foetuses were however found.


[Study of DNA melting in the region of the inversion of relative stability of AT and GC pairs]. Systematic data on the dependence of the melting curve parameters of DNA from different organisms on the concentration of salt (C2H5)5NBr have been obtained. The melting curves were studied by spectrophotometric as well as by microcalorimetric methods. The DNA melting range width is shown to pass through the minimum value delta0T = 0.6 +/- 0.1 degrees at the point of inversion of relative stability of AT and GC pairs that corresponds to the concentration of (C2H5)4NBr equal to 2.9 +/- 0.1 M. This concentration, as well as the value of delta0T, are the same for different DNA's of common chemical structure. The T2 and T4 DNA containing hydroxymethylated and glucosylated cytosine residues show an anomalous behaviour. The enthalpy of melting falls very slowly as the salt concentration increases. The possible causes of the observed value of delta0T are discussed. A conclusion is drawn that the main factor which governs the DNA melting process in the region of inversion of the relative stability of AT and GC pairs is the heterogeneity of stacking interaction between different base pairs.


Premature chromosome condensation, structural chromosome aberrations, and micronuclei in early mouse embryos after treatment of paternal postmeiotic germ cells with triethylenemelamine: possible mechanisms for chemically induced dominant-lethal mutatiions. Cytogenetic effects in preimplantation 4-8-cell mouse embryos have been investigated after treating paternal postmeiotic germ cells with triethylenemelamine (TEM). Dose-levels of TEM which do not affect fertilization but yield high incidence of dominant-lethal mutations in sperm and spermatids were shown to produce relatively high frequencies of (a) premature chromosome condensation (PCC), (b) structural chromosome anomalies (breakage-reunion phenomena), and (c) micronuclei in these embryos. The results indicate that genetic death of embryos is mainly due to imbalance (i.e. loss) of genetic material, either from breaks leading to lagging fragments and micronuclei, or from the segregation of various types of exchange figures (dicentrics, rings etc.) resulting in mechanical disturbances of cleavage division. It is suggested that PCC, to some extent, is an expression of TEM-induced long-lived lesions which, transmitted into the egg, prevent the chromosomes in question from replicating and/or condensing normally. This phenomenon could well be associated with loss of chromosome material resulting in embryonic death.


Repair by human cells of adenovirus-2 damaged by psoralen plus near ultraviolet light treatment. Adenovirus-2 is damaged by treatment with psoralen plus near-ultraviolet (UV) light is shown by reduced ability to infect human fibroblasts. The apparent sensitivity of the virus to this treatment depended upon the strain of cells used. The virus was 3-4 times more sensitive to the treatment when infecting xeroderma pigmentosum (XP complementation groups A or D) fibroblasts than when infecting normal fibroblasts. DNA extracted from virus preparations that had undergone such treatment was analyzed for treatment-induced crosslinks by gel electrophoresis and sedimentation in alkaline sucrose gradients. The fraction of adenovirus DNA molecules remaining non-crosslinked after treatment was found to correlate with the survival of the virus in normal fibroblasts. This result showed that the psoralen plus near-UV treatment gave rise to non-crosslink lesions (presumably psoralen-DNA mono-adducts), that were repairable by normal but not by XP fibroblasts, and suggested the possibility that normal fibroblasts cannot repair this type of crosslink in the DNA of an infecting adenovirion.


[The influence of complementary base pair interactions on secondary structure formation and conformational transitions in polynucleotides]. The calculations have been carried out of interaction energy between complementary base pairs of nucleic acids in the function of conformational parametres of double helix (Arnott's parameters) by the method of atom-atom potential functions. Interaction energy as a function of conformational parametres is valley-like and varies little along the bottom of the valley. The regions of interaction energy minima are compared with experimentally determined conformational parametres of nucleic acid double helices. On the basis of calculation results the pathways of conformational transitions between different forms of double-helical polynucleotides are discussed.


Caffeine inhibition of the repair of ultraviolet-irradiated adenovirus in human cells. Caffeine is shown to block repair of ultraviolet-irradiated adenovirus 2 when the irradiated virus infects normal human fibroblasts from a xeroderma pigmentosum (XP) variant. Such blockage is not observed when the irradiated virus infects XP fibroblasts belonging to XP complementation group A. Thus normal and XP variant cells have a caffeine-sensitive repair process. This may be either excision or an excision dependent repair process because fibroblasts belonging to XP complementation group A are believed to lack the excision repair process.


The influence of caffeine on cell survival in excision-proficient and excision-deficient xeroderma pigmentosum and normal human cell strains following ultraviolet-light irradiation. A uniform response to UV of four normal cell strains was demonstrated. One excision-proficient xeroderma pigmentosum variant strain (XP7TA) had a wild-type UV response but a second (XP30RO) was more sensitive. An excision-deficient xeroderma pigmentosum strain XP4L0 was substantially more sensitive than wild-type cell strains. A continuous post-irradiation treatment with non-toxic levels of caffeine enhanced the lethal effect of UV light in both xeroderma pigmentosum variant cell strains but not in cells from normal individuals. There was no detectable effect on cells from a xeroderma pigmentosum individual from complementation group A. These results correlate well with observations on the influence of caffeine on post-replication repair in the three classes of cells.


Potentiation by caffeine of ultraviolet-light damage in cultured human cells. Five cultured human cell lines (T-1 kidney, Chang liver, H.Ep. No. 2, HeLa-S3 and HeLa-O) were irradiated with ultraviolet light and immediately exposed to 1.0 and 3.0 mM caffeine for 44 h thereafter. This caffeine treatment reduced the surviving fraction (assayed by colony formation) of the irradiated population, but did not significantly reduce the colony-forming ability of unirradiated control cells. These findings suggest that many cultured human cell lines exhibit post-UV potentiation of potentially lethal damage by caffeine.


DNA strained breakage repair in ataxia telangiectasia fibroblast-like cells. Human diploid fibroblast-like cells derived from four patients with the genetic disease ataxia telangiectasia and from two non-mutant donors were examined for the repair of X-ray induced strand breaks in DNA. The ataxia telangiectasia cultures showed no significant differences from the non-mutant cultures in the kinetics and extent of strand repair. This suggests that the increased spontaneous and X-ray induced chromatid aberrations observed in ataxia telangiectasia cells are not caused by a defect in the repair of single strand breaks as might be suspected from a general model of aberration production.


On the relationship between spontaneous mutation rates in vivo and in vitro. Recent estimates of spontaneous mutation rates in man, in which previous sources of bias are corrected, indicate that the average is about 3 x 10(-7) per locus per generation, a much lower figure than is generally accepted. Assuming 100 to 1000 cell divisions between each gametic union, this information predicts that cellular mutation rats should be in the order of 10(-9) per locus per generation. Since none of the mutation rates measured in cultured cells are this low (average for seven characters equals 7 x 10(-7)), the size of mutation rates in cultured cells cannot be used to substantiate the claim of epigenetic inheritance. Furthermore, this information suggests that in multicellular organisms the germinal tissue is sequestered from mutagenic insult or subjected to selection against mutational damage so as to keep the genetic load of a species at a tolerable level. Alternatively, cell culture environments may present an extremely abnormal situation to somatic cells, thus elevating the mutation rate.


Sorosporium consanguineum: relation between variable nuclear condition and dissociation. Saprophytic development of Sorosporium consanguineum and its nuclear cycle were studied on laboratory media. During vegetative reproduction, the nuclei of the monokaryotic sporidia were shown to first migrate into developing bud cells where division occurs, one nucleus returning to the parent cell prior to completion of cell division. Following fusion of sporidia of opposite mating type and subsequent formation of infection hyphae, dikaryons eventually dissociated, giving rise to sporidia of both sex groups in the process. As a result of dissociation, shown to occur in several ways, "satellite" sporidial colonies characteristically formed in advance of the parent colony and fusions again occurred between sporidia of opposite mating type. Reports of variable nuclear condition of mycelia in other species of smut fungi in culture are discussed in light of these findings.


[Hospital infection of bronchopulmonary aspergillosis in infants and small children]. Routine histological investigations of the lungs of 38 children led to the discovery during the second half of 1970 of 4 cases of pulmonary aspergillosis in hospitalized children between 3 1/2 weeks and 2 years of age. Those cases represented 10.5% of all children, autopsiated during this period with an hospitalization period of more than 7 days. In two cases Aspergillus filaments did not invade pulmonary tissue, but in the two other cases Aspergillus mycelium had invaded the walls of adjacent pulmonary arteries with resultant arteritis, thrombosis and hemorrhagic infarction. The author believes, that the mycoses were acquired by inhalation of contaminated air. But he can not base this supposition of factual evidence.


Distributional patterns of mesophilous and thermophilous microfungi in two Bahamian soils. This study focuses on the characteristics displayed by mesophilous and thermophilous microfungal populations occurring in two tropical monodominant plant communities, a Cocos nucifera grove and a Casuarina equisetifolia forest, that provide distinctly different edaphic conditions. The mesophilous population sampled at 25 degrees C by the dilution plate method and the thermophilous population that developed on soil plates incubated at 45 degrees C consisted of 1693 isolates representing 60 species and 29 genera and 8887 isolates representing 20 species and 10 genera, respectively. The mesophilous propagules averaged 9,990 per gram dry soil in the coconut grove that lacks a litter layer, is low in moisture and organic matter and is subjected to high solar irradiation. The population was characterized by the prevalence of aspergilli and dematiaceous-sphaeropsidaceous forms and the near absence of mucoraceous isolates. Ascomycetes were common. The only widespread taxa were the three species, Aspergillus niger, Penicillium chysogenum, and Cladosporium cladosporioides. Species diversity was high and 73% of the isolates were cellulolytic. In the casuarina forest, adequate moisture and organic matter and a protecting litter layer provide a mesic environment. The mean number of mesophilous fungi per gram dry soil was 32,800. This figure is considerably lower than ones reported for mesic temperate communities and may be due to more rapid propagule removal through accelerated microfaunal and microbial activity. An abundance of mucoraceous and moniliaceous isolates and penicillia, and the rarity of aspergilli, dematiaceous-sphaeropsidaceous forms and ascomycetes characterize the population. The infrequency of aspergilli is thought to be due to their poor competitive ability. Eight species, Absidia cylindrospora, Penicillium notatum, Pestalotia cocculi?, Cylindrocarpon heteronema, Gliocladium roseum, Trichoderma viride, Paecilomyces marquandii, and Penicillium funiculosum were widespread in the area. Species diversity equaled that observed in mesic temperate communities. Less than one third of the isolates were cellulolytic. Phytopathogens were common, a feature characteristic of tropical populations. Thermophilous fungi averaged 33 per gram dry soil in the casuarina forest and increased to 943 per gram in the insolated soil of the coconut grove. Thermotolerant forms (94% of the isolates) were abundant and were principally species of Aspergillus and Chaetomium. Thermophilic fungi werur species, Ch. osmaniae, Ch. medusarum, Ch. sulphureum, and Thielavia arenaria, appear to be new records for western hemisphere soils.


Microflora of stored grain in international trade. Although the temperature of grain in the holds of ships arriving in Japan from Argintina, Australia, Canada, China and USA during 1966-67 varied with the grain, country of origin, and season, it was likely to be determined by the temperature of the grain when it was loaded into the ships. Dockage level varied among bulks of the same type of grain, but the mean dockage in any one crop was always larger when originating from the USA than from other countries. Generally the viability of the grain was good, but when it was reduced, interaction of variety and time seemed to be the principal cause. Field fungi - non-pathogenic Alternaria, and the pathogenic Helminthosporium and Fusarium species - tended to die out, during transport, thus reducing the hazards of new pathogenic strains being distributed across international boundaries. The non-pathogenic field fungi, Cladosporium and Phaeoramularia, were persistent. Although common in grain shipments from all countries, species of Aspergillus and Penicillium varied quantitatively with the different grains. In this respect, more Aspergillus spp. were found in grains originating in the USA and Australia than those originating in Canada. The primary contamination by storage fungi appeared to be at the source, at or after harvest and in storage prior to export.


[Copyright and natural sciences].

[Copyright and natural sciences]. Works in the natural sciences are provided with comparatively less copyright protection than literary works. Nevertheless, this protection is important for scientists. However, more recently, modern methods and techniques of information and documentation, such as reprography, microfilm archives, electronic data storage and retrieval, and data transmission have questioned the justification and effectiveness, even in principle, of this protection. A more detailed analysis demonstrates that this involves not so much a crisis of copyright law as a crisis of the entire field of scientific information.


Replication of feline sarcoma virus in cat embryonic kidney cells in the absence of transformation. The infection of cat embryonic kidney cells (CRC) with Gardner and Snyder-Theilen strains of feline sarcoma viruses (Ga-FeSV and ST-FeSV) do not lead to transformation and focus formation. The focus forming insusceptibility is shown to be stable and nontransmissable property of these cells. However, the CRC cells are permissive for ST-FeSV, and the viral production is 10 to 100 folds lower than in focus forming susceptible cat cells. Produced ST-FeSV(c) by CRC cells induced on cat embryonic cells FE in higher proportion round and fusiform (rf) foci and fusiform(f) foci. The f foci were not previously observed in original stock of ST-FeSV tested directly on FE cells. Attempts to detect some differences in morphology or in growth behavior between ST-FeSV infected and non-infected CRC cell population gave negative results.


The effect of long-term administration of N-(2-hydroxyethyl)palmitamide on the chemotherapy of RBA rat leukemia. The effects of N-(2-hydroxyethyl) palmitamide (PEA) a natural and antitoxic substance on the treatment of RBA rat leukemia were studied. Repeated administration of PEA prolonged substantially survival of leukemic animals in the course of the treatment with  cis-diamminedichlor-platinum (cis-Pt(II) in combination with cyclophosphamide, vincristine and methotrexate respectively. The most advantageous combination used was the cis-Pt(II) with methotrexate and PEA administration even improved the treatment results. The long-termed PEA treatment depressed first of all undesirable side effects and enabled to use higher therapeutic dosage of chemotherapeutics and improved the final results.


Further evidence on lymphocyte resistance of tumor-bearing in vitro rats to phytohemagglutinin. A study was made of the survival of peripheral blood lymphocytes in short-term cultures with a standard dose of phytohemagglutinin (PHA) in rats during the course of methylcholanthrene (MC)-induced carcinogenesis. Peripheral blood lymphocytes of (BDXLW)F1 hybrid rats were tested at various time intervals following MC application. The investigation involved a group of rats in which tumors had not appeared as yet after MC application, a further group with developed tumors of varying sizes, and a third group in which the tumors were extirpated, their peripheral blood lymphocytes being examined both before and at a definite time interval after the extirpation. Finally, another group of animals was investigated in which no tumor appeared up to 14 months after MC administration. The higher survival values of lymphocytes in PHA cultures in animals with primary MC-induced tumors in comparison with those of the control animals were found to be related to the presence of a progressing tumor. The results are discussed in terms of a possible change of T and B lymphocyte ratio in the peripheral blood in the presence of a tumor antigen.


Variations in sensitivity of synchronized Chinese hamster cells to oxic and anoxic X-ray exposures. V-79 Chinese hamster cells in monolayer cultures on glass surfaces were synchronized by treatment with hydroxyurea and exposed at different times thereafter to X-rays in the air or in oxygen-free argon. Survival determinations indicated that the oxygen enhancement ratio OER as expressed by the ratio of the respective D0 values varied over a narrow range in the different phases of the cell cycle. These changes resulted from cyclic alterations in both aerobic and anaerobic D0 values, and perhaps in n values.


The effect of anemia on the radiotherapy results of the uterine cervix cancer. Relationship between hemoglobin level and survival and/or recurrence rate was studied in radiation treated group of postmenopausal women with uterine cervix carcinoma. The data suggest that anemia alters unfavorably the effectiveness of radiotherapy. A possible explanation of the lowered control rate is that due to deficiency of tissue oxygenation by reduced oxygen carriage proportion of hypoxic cells increases and impairs the radiosensitivity.


Long-term results in rectum carcinoma. Patients followed up during the period 1959-1968. During the period 1959 to 1968, a total of 158 patients with carcinoma of the rectum were treated at the surgical department of the Oncological Institute in Bratislava. All these patients were retro spectively classified according to the TNM system into four clinical stages as follows: Stage I -- 26 (16.46%). Stage II -- 12 (7.59%), Stage III -- 61 (36.61%) and Stage IV -- 59 (53.39%) of the patient. Surgical treatment was supplemented with irradiation in 85 (53.73%) of the patients with chemotherapy in 15 (9.49%). All the findings were verified histologically. Favorable results as regards the 5-year survival rate in accordance with literature data were achieved in the early stages of the affection, while in advanced stages this survival rate was rather low, the majority of the patients died in the first and second year following initiation of treatment. The authors express the view that in future, oncologists will have to devote more attention to an early diagnosis and treatment of precanceroses, and this not solely in patients with a carcinoma of the rectum, but also in its other localizations.


Diagnosis and treatment of bilateral traumatic carotid-cavernous sinus fistulae. The authors report the diagnosis and successful treatment of a case of traumatic bilateral carotid-cavernous sinus fistula. Direct tamponade of the fistula with a Fogarty catheter and ligation of all cervical carotid vessels was carried out on the left side following ligation on the right side of the common carotid, the internal carotid extra- and intracranially, and of the external carotid artery. The pre-requisite for this procedure was the development of a functional collateral circulation via the posterior communicating arteries from the basilar system. The 18 months follow-up report and the rare reports in the world literature on the operative techniques and the results of treatment of similar cases are discussed.


[Clinical and morphological considerations concerning "medulloepithelioma" (author's transl)]. The clinical course and autopsy findings in a 20 months old child with a so-called medulloepithelioma of the brain stem are reported. The histological features of this tumour are described. Ten previous cases in the literature are reviewed and the controversial problems of this entity are discussed. It seems reasonable to place this malignant tumour in the group of ependymomas; in detail, the definition "embryonic ependymoma"; proposed by Fowler, appears to be the most suitable, because it comprises all morphological and biological features of this rare malignant tumour.


[Endoscopy of the spinal canal (author's transl)]. The intraspinal endoscopy was carried out by means of a recently developed Selfoc-endoscope. The optical principle of the Selfoc-glass rod was described. The endoscopic observations in the preliminary experiment on dogs and in 6 clinical cases were reported. Our experiences showed the usefulness of Selfoc-endoscope for the clinical spinaloscopy.


Remarks on the surgical treatment of the craniosynostoses. Technical aspects and results of a surgical procedure for craniosynostoses are exposed. Fragmentation-recomposition of the anterior part of the cranial vault in cases of brachi-, acro-, turri- and trigono-cephaly gives both an effective decompression and a satisfactory cosmetic result.


[Symptom picture of a unilateral fronto-medial falcial meningioma with extrapyramidal symptomatology]. A colourless affect, without neurological symptoms was for decades assumed to be a character attribute of the patient, until the age of 55 years when she developed an akinetic symptom-complex with tremor, but with no rigidity. In the light of the history, the investigations and the operation findings, the symptoms appeared to have a clear aetiological connection with a unilateral, mandarin-sized, fronto-medial meningioma on the inferior edge of the falx. It seemed likely that this had been growing since her youth. The reversible symptoms were judged to be the result of pressure on the mid-brain, with resultant ciuculatory disturbances.


Inhibition of ovulation induced with PMS and HCG by a melatonin-free extract of bovine pineal powder. Using borate buffer a substance that suppresses the ovulation induced with PMS and HCG in immature mice was obtained from acetone-defatted bovine pineal powder by an extraction method similar to that used for an extraction of a gonadotropin-inhibiting substance in urine. This gonadotropin inhibitor in the pineal powder differs from melatonin or arginine vasotocin and seems to be different from the water soluble antigonadotropic substance which has been isolated from the bovine and ovine pineal. Partial purification of the gonadotropin inhibitor was accomplished by a Sephadex G-100 column.


[Endocrine glands of Chironomus thummi Kief. during larval development and metamorphosis]. The general morphology of the complex of endocrine glands in Chironomus thummi is described (corpora allata, peritracheal glands, cardial bodies). Each of these glands is characterized during the 3rd, 4th larval instars and metamorphosis by specific developmental features. Enlargement of corpora allata is due, mainly, to more than 10-fold increase in cell number. The process of growth in the peritracheal gland is realized mainly at the expense of increase in cell size and formation of polytene nuclei; the latter is witnessed both by nuclear morphology and increase of DNA content per nucleus. It was shown by cytophotometric measurements that DNA content per nucleus in the peritracheal gland of a just moulted larva of the 4th instar amounts to 0.202 +/- 0.02 relative units, in prepupa to 2.98+/-0.01, whereas the corresponding values for nuclei of corpora allata equal 0.107+/-0.01 and 0.212+/-0.1. The number of cells and the morphology of nuclei suffer no significant changes in cardial bodies but 2 giant cells intimately connected with cardial bodies increase in volume from 18 to 200,000 mu3 and typical polytene chromosomes form in them.


[The morphofunctional condition of the basic organ systems, life span and fecundity of the domestic cricket, Acheta domestica, during normal imaginal development and following allatectomy]. 3 main periods of imaginal development: juvenility, reproduction, ageing, were established in Acheta domestica and characterized by morphological and functional features of some organs (integument, wings, fat body, wing muscles, ovaries, and body proportions). Allatectomized crickets remain in the first period up till the day of death; this allowed to suggest that the hormone of corpora allata in imago controls the normal correlated development of different organs and tissues and ensures the transition to subsequent periods of imaginal ontogenesis. In allatectomized crickets of both the sexes, the duration of imaginal life is markedly longer and the fecundity of females is much lower. It is suggested that the hormone of corpora allata controls the life span and the fecundity independently.


[The mechanism of inactivation of the bird erythrocyte genome. III. Pathways of terminal differentiation of erythrocytes]. Under the conditions of acute phenylhydrazine anemia in pigeons, early erythroblasts develop in reticulocytes with basophilic cytoplasm directly by passing the stages of polychromatophilic and ortochromic erythroblasts. During the maximum activity of bone marrow erythropoiesis stimulated by anemia over 80% of reticulocytes develop in such a way. A hypothesis is put forward to the effect that there exist in birds two alternative pathways of erythropoiesis: the main pathway which ensures the slow repopulation of blood by erythrocytes under normal conditions and the reserve pathway which opens for a short time under anemia and ensures rapid increase of the erythrocyte titer in blood up to its normal value.


[The development of differentiation of pigment epithelium in teleosts and its stimulation to metaplasia]. The time was determined when pigmented epithelium acquires stable differentiation and the possibility was investigated for pigmented epithelium to transform in retina at different developmental stages in the Issyk-kul chebatchok Leuciscus bergi (Cyprinidae). By means of implantation of a layer of pigmented epithelium in pericardium it was established that the pigmented epithelium cells acquired stable differentiation rather early. When an already pigmented layer of pigmented epithelium was implanted in the cavity of a lensless eye, its cell transformed in retina under the influence of the whole retina. Conditions of pigmented epithelium metaplasia in retina in teleosteans proved to be similar with those for frogs.


[Temporary patterns in the embryonic development of the beluga]. The data concerning the absolute and relative duration of different periods of the beluga embryogenesis are obtained and the relative durations of the same periods of embryogenesis in beluga, sevryuga (Acipenser stellatus) and sturgeon (Acipenser güldenstädti) were compared. The relative durations of cleavage, gastrulation and early organogenesis in beluga are rather stable within the zone of optimal temperatures and similar to those in sturgeon and sevryuga. In beluga the relative duration of the period between the insemination and the appearance of the 1st cleavage furrow on the egg surface and the relative duration of the second half of embryogenesis (from the formation of heart rudiment till the hatching of single larvae) are somewhat less.


[The osteogenic role of the dura mater in adult rabbits during regeneration of the skull]. It was shown in experiments with adult rabbits that the regeneration of skull vault bones after artificial trauma proceeds, mainly, at the expense of osteogenic activity of dura mater, rather than by means of outgrowth of bone from the defect margins. During regeneration, dura mater connects with the granulation tissue which fills the area of defect. The first bone islets are formed by the surface layer of dura mater near the defect margins and then all over the defect area. During regeneration bone islets merge with each other and with the old bone at the defect margins. In experiments with separation of the defect margins from dura mater by millipore filter, regeneration is insignificant over the filter near the old bone margins (bone trabeculae form which close destructed bone marrow cavities); the bone forms intensively under the filter on dura mater. In experiments with the removal of a piece of skull bone together with the adjacent region of dura mater, no bone regeneration occurs, the defect area is filled by the scar tissue.


[Migration of glial cells in the brains of intact mice and mice with brain injuries during the first hours after DNA synthesis and cell division]. The behaviour of labelled (3H-thymidine) glial cells was studied in the brain of intact mice and mice with mechanical trauma of brain. Formation of pairs of labelled cells and their subsequent disjunction in the brain regions under study occurs at different rates. The rates of these processes in white matter and subependymal zone exceed those in parietal cortex, thalamus and hypothalamus. The brain traumatization does not influence the rate of disjunction of separated glial cells. Angles between axes of separated cells are different in the brain regions under study. In cortex and white matter, separated cells with axial angles equal to 180 degrees predominate whereas in thalamus, hypothalamus and subependymal zone many separated cells have axial angles below 180 degrees (120-160 degrees). The possible relationship between the form of the brain regions under study and the value of axial angles of separated cells is discussed.


[Ribosomal RNA synthesis in haploid and diploid loach embryos]. rRNA synthesis was compared in the loach haploid (In) and diploid (2n) embryos. The relative intensity of synthesis was evaluated by 14C-uridine incorporation in 27S and 18S rRNA isolated from ribosomes taking into account label incorporation into total acid-soluble fraction and phosphrylated uridine derivatives. Label incorporation into rRNA, in reference with DNA content in 1n and 2n embryos, suggests that the level of rRNA synthesis per DNA unit in haploids is twice that in diploids whereas, in reference per cell, the same amount of ribosomes is synthesized both in haploids and diploids. The data obtained show that the amount of rRNAs synthesized in the loach embryogenesis does not depend on ploidy.


[Polar distribution of RNA in the cytoplasm of Acetabularia mediterranea]. The distribution of total RNA and its individual fractions in two regions of Acetabularia mediterranea stem during regeneration was investigated. During regeneration of both the nuclear and enucleated cells, RNA concentration increases in the cytoplasm of growth zone whereas it changes insignificantly in the central stem region. A study of the qualitative RNA composition in the same stem regions has shown that during regeneration high molecular weight RNA fractions (main peaks - 0,56-10(6) and 1.04-10(6) Dalton) are found in the growth zone and are practically absent from the central cell region. Low molecular weight RNA (supposedly, tRNA and products of RNA destruction) are present in both the cell regions under study.


[Autoantibodies and immunologic theories]. A hypothesis is put forward to the effect that immunological phenomena represent a particular case of the transport of metabolites, rather than obligatory "defense mechanism". This hypothesis excludes the necessity in additional postulates (forbidden clones, somatic mutations, cells-repressors etc.) to account for the basic immunological phenomena, such as recognition, appearance of autoantibodies and tolerance. It suffices to assume that: 1) autolytic enzymes destroy "their" antigens but cannot destroy completely "foreign" antigens; 2) as a result of decomposition of antigens by enzymes, "tolerogens" may appear which block the receptors in immunocompetent cells thus preventing the appearance of antibodies; 3) cells capable to synthesize autoantibodies exist in the normal organism but not activated due to the absence of "their" antigens. When such antigens appear, they initiate the synthesis of antibodies. The hypothesis advanced may appear too simple as compared with the existing theories, but experiments have to confirm it.


[Peptide hydrolase activity during embryonic carp development]. It was established that in the carp the process of embryonic and early postembryonic development was accompanied by the increase in the activity of both the trypsin- and chemotrypsin-like peptide hydrolases. This increase is most evident  in larvae with resorbing yolk. The total and protein nitrogen content suffers no changes during embryonic and early postembryonic development. The content of non-protein nitrogen increases from the stage of the middle of segmentation on attaining the maximum level in larvae with resorbing yolk.


[Analytic resolution of the equilibrium equation of growth]. A binomial bioenergetical balance growth equation is considered. The analytical solution of this equation is proposed under certain limitations of parameters. This equation was shown to describe both the mass accumulation and loss in cases of negative energetical balance, thus allowing to widen the domain of application of the equation.


[A radioautographic study of protein synthesis in loach blastoderm]. The dynamics of protein synthesis in the loach embryos has been studied by means of autoradiography at the stages of cleavage, blastula and gastrula. During the synchronous cleavage divisions, nuclear proteins are mainly synthesized. From the early blastula stage until the early gastrula stage, the intensity of nuclear protein synthesis increases 2.5 times whereas the intensity of cytoplasmic and total protein synthesis is low and relatively constant. After the onset of gastrulation the intensity of nuclear and cytoplasmic protein synthesis increases 3-4 times and at the late gastrula stage it decreases twice as compared with that at the midgastrula stage. During blastulation, no regional differences in the intensity of nuclear and cytoplasmic protein synthesis were found. With the onset of gastrulation, a vegeto-animal gradient of labeled aminoacid incorporation into nuclear and cytoplasmic proteins appears. During gastrulation, reliable differences were found between the intensity of labeled aminoacid incorporation into proteins of the cells of intact and dissociated blastoderms. During this period, the intensity of protein synthesis in embryonic shield is higher than that in the extraembryonic part of blastoderm.


[Local proliferation of cells of the granular layer of the dentate gyrus of the mouse hippocampus during postnatal ontogenesis and following brain injury]. The local cellular proliferation takes place in the inner part of the dentate gyrus granular layer, the subgranular zone, of mice. The proliferating cells of the subgranular zone are one of two sources of postnatal neurogenesis of the granular layer (another source-cells of the subependymal zone). The subgranular zone becomes markedly thinner with the age but even in adult mice the cellular proliferation occurs in it. Under the brain trauma, the proliferation of the subgranular zone cells is activated. Besides cell division in the subgranular zone, there is insignificant proliferation in the differentiated part of the granular layer. Special studies are, however, necessary to identify dividing cells in the differentiated part of the granular layer.


[Estrogens in the tissues of guinea pig embryos]. The content of estrogens was determined in tissues of the guinea pig embryos, blood of pregnant females and placenta by means of biological testing. It was the highest in embryonic ovaries at all developmental stages. The sexual dimorphism in estrogen content was found in embryonic suprarenals: it was higher in females than in males. The estrogen content in blood of male embryos and pregnant females was similar but lower than that in female embryos. Estrogens were also found in placenta and their traces were detected in spleen, brain, hypothalamus and uterus. The problem of possible participation of estrogens in the sex differentiation of female embryos is discussed.


[A change in the puff spectrum during development of Drosophila virilis]. The puff spectrum has been studied in the salivary gland chromosomes of D. virilis from 48 hrs of the 3rd larval until the gland lysis. 142 puffs were observed in the D. virilis genome. Among them, 43% were observed at all developmental stages and other puffs were unstable: 47.1% appear at a certain stage and degrade or remain until the gland lysis; 9.9% are characterized by the "pulse" activity, i.e. they appear at a certain stage, degrade and reappear. The number of newly appeared puffs exceeds that of fully degraded ones, i.e. the number of puffs during the gland development until its lysis increases constantly. At the stage of puparium formation, sexual differences in the puff length were found: puffs were longer in males than in females.


[An analysis of cedar of Lebanon (Cedrus libani A. Rich.) pollen grain development in cultural plantings]. A cytological study of the Cedrus libani mature pollen from 3 culture areas (Italy, France, USSR) has shown that 69-71% of pollen grains have two-celled protallium and antheridial cell. About 5% of pollen grains are characterized by accelerated of delayed development, otherwise apparently normal. The pollen sterility (up to 30% of grains) is due to the abortive spore development. Anomalous cenocyte and multinuclear pollen grains were found thus suggesting that multicellular haploid structures capable of further growth and development may arise in the course of natural anther development.


[Photic induction of polar growth in enucleated fragments of Acetabularia mediterranea]. The process of induction of polarity in enucleated fragments (EF) of Acetabularia mediterranea has been studied by the method of local illumination. A device is described which allows to illuminate one part of EF at 2, 500 lx and another at 5 lx. The local illumination of a part of EF during 10-24 hrs was shown to polarize with a high probability the subsequent growth and formation of caps at the subsequent uniform illumination. Using the method of successive illumination and darkening of apical and basal portions of EF, it was shown that the initial stages of induction were partially reversible and the complete determination of polarity took place after the initiation of the cap anlage. After the short-term induction by light (2500 lx), the darkening of the growth zone inhibits completely the process of cap initiation, but already at 100 lx the EF previously induced at 2 500 lx are initiated and grow. While using the local illumination of grafts of EF from two species, A. crenulata and A. mediterranea, with their subsequent fragmentation and the analysis of cap morphology, it was shown that the induction of polar growth did not provide the directed transport of the factors controlling morphogenesis to the future growth zone.