Immunofluorescent demonstration of double-stranded RNA and virus antigen in RNA virus-infected cells

The indirect immunofluorescence procedure has been used for demonstration of double-stranded RNA in cells infected with reovirus, poliomyelitis, and tick-borne encephalitis (TBE) viruses. Rabbit sera against poly(A)-poly(U) and poly(I)-poly(C) react specifically with double-stranded RNA. Double-stranded RNA is found in the cytoplasm of the cells infected with high multiplicities of poliomyelitis and tick-borne encephalitis viruses 3 hr postinoculation. In parallel, preparations were stained with sera against viral proteins. During one cycle of reproduction the dynamics of accumulation of double-stranded RNA and virus protein was synchronous both for poliomyelitis and tick-borne encephalitis viruses. When poliovirus-infected cells degenerated, the number of cells containing TBE virus double-stranded RNA decreased markedly while the proportion of cells containing virus protein remained high.     

Effect on different mutant p53 on cell sensitivity to cytostatics

Expression of human p53 carrying missense mutations at codons 175 (His175), 194 (His194), 248 (Trp248), and 273 (His273) has different effects on sensitivity of K562, 10(1), 10(3), and Rat1 cells to the antitumor drugs methotrexate, etoposide, vinblastine. These effects of mutant p53 depend on both particular amino acid substitution and cell context (histogenetic type, status of the second allele,etc.) Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 3, pp. 324–327, March, 1999     

In vivo optical coherence tomography imaging of human skin: norm and pathology

Background/aims: Since the majority of skin diseases are known to be accompanied by structural alterations, research efforts are focused on the development of various novel diagnostic techniques capable of providing in vivo information on the skin structure. An essential parameter here is spatial resolution. In this paper we demonstrate the capabilities of optical coherence tomography (OCT) in detecting in vivo specific features of thin and thick skin. A particular focus is made on the identification of OCT patterns typical of certain pathological processes in skin, by performing parallel histological and tomographical studies. Methods: To obtain images of the skin, we used a compact fiber OCT system developed at the Institute of Applied Physics of the Russian Academy of Sciences. A low coherence source (superluminescent diode) operated at a wavelength of 1280 nm; the output power was 0.5–2 mW. This power is low enough to conform to the ANSI safety standards for light exposure. The in‐depth resolution limited by the spectral bandwidth (40–50 nm) of the probing light was ～20 μm. The lateral resolution determined by the probe light focusing ranged from 15 to 30 μm. In this series of experiments the maximum depth of imaging did not extend beyond 1.5 mm. Obtaining images of skin regions 2–6 mm long took 2–4 s. OCT capabilities for imaging normal skin of different localization and some skin diseases were studied in 12 healthy volunteers and 24 patients. Results: OCT imaging of the skin can detect in vivo such general pathological reactions of the human body as active inflammation and necrosis. OCT is useful for in vivo diagnosis of some specific processes in the skin, including hyperkeratosis, parakeratosis and formation of intradermal cavities. OCT imaging is noninvasive and therefore allows frequent multifocal examination of skin without any adverse effects. OCT can perform monitoring of disease progress and recovery in the course of therapy. Morphometric studies, measurements of the depth and extension of skin pathology within the human body can be easily performed by OCT. Conclusions: OCT allows imaging of subsurface soft tissues with the spatial resolution of 15–20 μm, a resolution one order of magnitude higher than that provided by other clinically available noninvasive diagnostic techniques. An imaging depth of up to 1.5–2 mm, given by current OCT technology, is sufficient to examine the skin. Real time OCT imaging can provide information not only on the structure, but also on some specific features in the functional state, of tissues. OCT imaging is a noninvasive technique, i.e., OCT does not cause trauma and has no side effects since it utilizes radiation in the near infrared wavelength range at a power as low as 1 mW.     

Immunogenicity of inactivated polio vaccine with concurrent antiviral V-073 administration in mice

Immunization of mice with inactivated polio vaccine (IPV) with concurrent dosing of poliovirus antiviral V-073 showed no detrimental impact on the elicitation of serum-neutralizing antibodies. A strategy involving coadministration of antiviral V-073 and IPV can be considered for the management of poliovirus incidents.     

Subtotal vital pulp extirpation using different medical preparations (experimental morphological research)

Pulp stump and periapical tissue reaction to root canal filling with material containing calcium hydroxide and potassium nitrate after subtotal vital extirpation of the pulp was studied in 12 teeth of 6 green monkeys. Use of the material containing potassium nitrate was found to result on the 90th day of the experiment in the formation of a biologic barrier of secondary cement at the dental root apex. Such result was not achieved with calcium hydroxide-containing material. Other advantages of potassium nitrate-containing material were detected, consisting in a more rapid recovery of structural shifts in the pulp stump and periapical tissues.     

Correlation between amount of virus with altered nucleotide sequence and the monkey test for acceptability of oral poliovirus vaccine.

Production of live attenuated oral poliomyelitis vaccine (OPV) requires rigorous neurovirulence safety testing of each vaccine lot, currently carried out in monkeys. It has been reported that a change from 472-U to 472-C in the type 3 OPV RNA is associated with an increased histologic lesion score produced upon intraspinal inoculation of the mutant virus in monkeys. We have developed a method, based on polymerase chain reaction, for measuring the relative abundance of these mutant sequences directly in vaccine preparations and used this method to evaluate the proportion of 472-C in 40 different lots of type 3 OPV. Six vaccine lots that had failed the intraspinal monkey neurovirulence test contained a higher proportion of 472-C than all other lots that had passed this test. OPV type 3 virus containing 472-C was rapidly selected during serial passages in African green monkey kidney cells that are used for manufacturing of the vaccine. We have also found that the wild-type poliovirus type 3 strain Leon/37, from which the vaccine strain was originally derived, contained a mixture of 472-U and 472-C sequences. No other mutations in OPV type 3 RNA have been detected by similar assays at position 2034, also associated with attenuation, or at several other positions reported to be altered in some vaccine preparations. Our results suggest that molecular diagnostics may provide a supplement or a potential alternative to animal testing of live attenuated vaccines.