ART-CH: a VL30 in chickens?

The complete sequence of ART-CH, a recently found chicken retrotransposon (A. V. Gudkov, E. A. Komarova, M. A. Nikiforov, and T. E. Zaitsevskaya, J. Virol. 66:1726-1736, 1992), was characterized. ART-CH has the structure of a 3,300-bp-long provirus, including two 388-bp long terminal repeats (LTRs) (U3, 245 bp; R region, 17 bp; and U5, 126 bp), a tRNA(Trp)-binding site, and a polypurine tract, similar to avian leukosis viruses. At least some of the approximately 50 genomic copies of ART-CH are transcribed into polyadenylated RNA, which is initiated and terminated at the expected sites within the LTRs. In contrast to the regulatory sequences involved in proviral expression and replication, the internal regions of ART-CH seem to be completely defective. Several short regions of homology with avian leukosis virus genes, most of which encode gag-related sequences, were found among different reading frames of ART-CH, which are not organized like regular retroviral genes. Both sequence analysis and restriction fragment length polymorphism analysis revealed a high degree of sequence (97% homology) and structural similarity among members of the ART-CH family, indicating their common origin and recent penetration into chicken DNA. ART-CH sequences were detected in mouse cells infected with Rous sarcoma virus produced by an ART-CH-expressing Rous sarcoma. These data are consistent with the hypothesis that ART-CH belongs to a class of defective retrotransposons whose replication strategy requires the use of helper viruses. They might originate from an avian leukosis virus-related retrovirus which completely lost its coding capacities as a result of multiple mutations and deletions. These features apparently group ART-CH with the VL30 retrotransposons of rodents.     

NPH4, a conditional modulator of auxin-dependent differential growth responses in Arabidopsis

Although sessile in nature, plants are able to use a number of mechanisms to modify their morphology in response to changing environmental conditions. Differential growth is one such mechanism. Despite its importance in plant development, little is known about the molecular events regulating the establishment of differential growth. Here we report analyses of the nph4 (nonphototropic hypocotyl) mutants of Arabidopsis that suggest that the NPH4 protein plays a central role in the modulation of auxin-dependent differential growth. Results from physiological studies demonstrate that NPH4 activity is conditionally required for a number of differential growth responses, including phototropism, gravitropism, phytochrome-dependent hypocotyl curvature, apical hook maintenance, and abaxial/adaxial leaf-blade expansion. The nph4 mutants exhibited auxin resistance and severely impaired auxin-dependent gene expression, indicating that the defects associated with differential growth likely arise because of altered auxin responsiveness. Moreover, the auxin signaling events mediating phototropism are genetically correlated with the abundance of the NPH4 protein.     

Refinement of technique for cosmonaut's body radiation loading estimation using of orbital station dosimetric monitoring system

Proposed is a technique for estimation of radiation loading of cosmonauts' body from the data of the space station radiation monitoring system by bringing the objective to a linear mathematical model. Resulted matrix ratios allow to work out the challenge; test calculations illustrating efficiency of the proposed technique are included.     

Activity of threonine deaminase and biosynthesis of avermectins in the culture of Streptomyces avermitilis

The influence of ammonium, threonine, isoleucine and valine on the activity of threonine deaminase and the biosynthesis of avermectins in the culture of two mutants of Streptomyces avermitilis, i.e. a sensitive one and a resistant one with respect to alpha-amino-beta-oxyvaleric acid, a threonine antimetabolite, was studied. It was shown that the synthesis of threonine deaminase was induced by threonine and valine in the mycelium of both the mutants. The level of threonine deaminase was higher in the mycelium of the antimetabolite resistant mutant. The antibiotic activity of the resistant mutant was lower while the relative content of the group B avermectins in the pool of the synthesized avermectins was higher than that in the culture of the sensitive mutant.     

The dynamic follow-up of the status of patients with acute pancreatitis using a degree-of-severity scale

The authors have developed a method of dynamic control over the patients with acute pancreatitis using the lineal coefficient of gravity rating, which is based on objective parameters. This dynamic control was applied in 300 patients and made it possible to choose the most effective methods of treatment.     

DNA- and RNA-hydrolyzing antibodies from the blood of patients with various forms of viral hepatitis

Antibodies (Abs) hydrolyzing proteins, DNA, and RNA are detected in the blood of patients with various autoimmune diseases. In the present work, homogeneous preparations of IgG Abs from the blood of the healthy donors as well as patients with A, B, C, and delta types of viral hepatitis, influenza, pneumonia, tuberculosis, tonsillitis, duodenal ulcer, and some types of cancer were purified. For the first time, the fraction of IgG and its Fab fragments of patients with viral hepatitis were shown to have high DNA- and RNA-hydrolyzing activity. In case of Abs from the healthy donors and patients with other diseases, high activity of Abs was not detected. The data obtained by various methods indicate that the activity of hepatitis Abs is an intrinsic property of the immunoglobulins. The relative rates of hydrolysis of cCMP, poly(U), poly(A), poly(C), and tRNA(Phe) by hepatitis Abs were compared with those of RNase A and other RNases from human blood. Significant differences in activities of Abs and nucleases in hydrolysis of model substrates were demonstrated. Thus, catalytically active Abs can appear in the blood of patients not only with autoimmune disorders, but with viral diseases as well.