The Carboniferous carbonates of the Dombar Hills (western Kazakhstan) and the problem of the Viséan–Serpukhovian boundary

The Upper Viséan–Serpukhovian ammonoid-rich carbonates in the Dombar Hills (Aktobe Region, western Kazakhstan) provide an excellent opportunity to calibrate the ammonoid and conodont zonations around the base of the Serpukhovian Stage, and are important for interregional correlation. A section in the Dombar Hills spanning the Viséan–Serpukhovian boundary is measured and its fossil content is analyzed. Two ammonoid genozones (Hypergoniatites-Ferganoceras and Uralopronorites-Cravenoceras) and two conodont zones (Lochriea nodosa and Lochriea ziegleri) are recognized. The section displays a contact between the Hypergoniatites-Ferganoceras and Uralopronorites-Cravenoceras ammonoid genozones in a continuous succession and an evolutionarily early appearance of the genus Cravenoceras. The base of the Serpukhovian Stage is drawn at the level of the first appearance datum (FAD) of the conodont Lochriea ziegleri, which, as in the Verkhnyaya Kardailovka section (potential GSSP candidate, South Urals, Russia) enters within the Hypergoniatites-Ferganoceras ammonoid Genozone.     

Antimicrobial Peptides in Health and Disease (Review)

The review describes the latest data on the role of antimicrobial peptides (AMPs) in health and disease, as well as their structure and mechanisms of action. AMPs mediate protection by both direct lysis of bacteria and also by regulation of inflammation and chemotaxis, thus demonstrating immunomodulatory properties. A large amount of data shows that AMPs play an important role in the pathogenesis of multiple chronic diseases with genetic predisposition, such as atopic dermatitis, rosacea, and scleroderma.     

The Reduction of Cr(VI) by Bacteria of the Genus Pseudomonas

Non-nitrate-reducing collection bacteria from the genus Pseudomonas were found to be able to use hexavalent chromium as a terminal electron acceptor. The reduction of Cr(VI) was accompanied by an increase in the cell biomass. At Cr(VI) concentrations in the medium lower than 15 mg/l, the non-nitrate-reducing pseudomonads reduced Cr(VI) less efficiently than did denitrifying pseudomonads. In contrast, at Cr(VI) concentrations higher than 30 mg/l, Cr(VI) was reduced more efficiently by the non-nitrate-reducing pseudomonads than by the denitrifying pseudomonads.     

Late Activation of Interferon-Induced Genes IFI-54K and IFI-56K in Human RH Cells Infected with Tick-borne Encephalitis Virus

The genes that were induced and suppressed in human embryonic kidney cell line RH upon the infection with tick-borne encephalitis virus were studied by the method of subtractive hybridization. The expression of interferon-induced genes IFI-54K and IFI-56K in the infected cells was found to increase 50–100-fold.     

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

Chronic wasting disease (CWD) is the only known transmissible spongiform encephalopathy affecting free-ranging wildlife. Although the exact mode of natural transmission remains unknown, substantial evidence suggests that prions can persist in the environment, implicating components thereof as potential prion reservoirs and transmission vehicles.^1–4 CWD-positive animals may contribute to environmental prion load via decomposing carcasses and biological materials including saliva, blood, urine and feces.^5–7 Sensitivity limitations of conventional assays hamper evaluation of environmental prion loads in soil and water. Here we show the ability of serial protein misfolding cyclic amplification (sPMCA) to amplify a 1.3 × 10⁻⁷ dilution of CWD-infected brain homogenate spiked into water samples, equivalent to approximately 5 × 10⁷ protease resistant cervid prion protein (PrP^CWD) monomers. We also detected PrP^CWD in one of two environmental water samples from a CWD endemic area collected at a time of increased water runoff from melting winter snow pack, as well as in water samples obtained concurrently from the flocculation stage of water processing by the municipal water treatment facility. Bioassays indicated that the PrP^CWD detected was below infectious levels. These data demonstrate detection of very low levels of PrP^CWD in the environment by sPMCA and suggest persistence and accumulation of prions in the environment that may promote CWD transmission.Key words: prions, chronic wasting disease, water, environment, serial protein misfolding cyclic amplification     

Freshwater crayfish invasions in South Africa: past,present and potential future

Freshwater crayfish invasions have been studied around the world, but less so in Africa, a continent devoid of native freshwater crayfish. The present study reviews historical and current information on alien freshwater crayfish species introduced into South Africa and aims to indicate which areas are at risk from invasion. As is the case elsewhere, South Africans have shown a keen interest in both farming and keeping freshwater crayfish as pets, which has resulted in Cherax cainii, Cherax destructor, Cherax quadricarinatus and Procambarus clarkii being introduced to the country. There is evidence of successful establishment in the wild for C. quadricarinatus and P. clarkii in different parts of the country. Species distribution models suggest that the eastern part of the country and parts of the Eastern and Western Cape are at higher risk of invasion. At present, illegal translocations represent the most likely pathway of crayfish spread in South Africa. A continued risk of invasion by freshwater crayfish species in South Africa is highlighted, which reinforces the need for more research, as well as for strong mitigation measures, such as stronger policing of existing regulations, management or eradication where feasible and public education.     

Transplantation of Neuronal Precursors Derived from Induced Pluripotent Stem Cells into the Striatum of Rats with the Toxin-induced Model of Huntington’s Disease

Introduction. Huntington’s disease (HD) is a severe neurodegenerative disorder characterized by choreic hyperkinesis, cognitive decline, behavioral disorders, and progressive neuronal death, mostly in the striatum. Since HD is a fatal disorder, searching for efficient treatment methods, including those based on cell replacement therapy, is quite relevant. The experimental models of HD are used increasingly often. The objective of the study was to assess effectiveness and safety of transplantation of neuronal precursors differentiated from induced pluripotent stem cells (iPSCs) from a healthy donor into the striatum of rats with 3-NPAinduced HD model. Materials and methods. We studied the influence of neurotransplantation on the behavioral effects in rats with HD model induced by intrastriatal injection of 3-nitropropiotic acid (3-NPA). In the study group of animals (n = 11), human neuronal precursors derived from iPSCs of a healthy volunteer were transplanted into the caudate nuclei (5 × 10⁵ per 5 μL of normal saline solution bilaterally); the control group of animals (n = 10) received normal saline solution. The animals were tested using the ANY-maze video tracking system; the parameters of the open-field test and the conditioned avoidance response test were evaluated. Results. An analysis of behavioral effects after transplantation demonstrated that introduction of neuronal iPSC derivatives into the caudate nuclei of rats with induced HD model was accompanied by recovery of locomotor activity of the animals (horizontal and vertical), as opposed to the control group. It was found when testing the reproducibility of the conditioned avoidance responses that the conditioned avoidance responses in control animals were weakened, whereas intrastriatal transplantation of neurons abruptly increased the latency of moving into the dark compartment of the chamber in the conditioned avoidance response test. Conclusions. The pilot experiment using the HD model showed that neurotransplantation using iPSC derivatives recovers the reduced locomotor activity in rats and improves memory trace keeping, which contributes to correction of locomotor and cognitive disorders induced by 3-NPA neurotoxin.     

电子供体及受体对棕色固氮菌抗氨阻遏能力的影响

电子供体连二亚硫酸钠,甲基紫精及电子受体亚甲蓝均能强烈的抑制棕色固氮菌表达固氮活性,并引起该菌的抗氨阻遏能力减弱,适当提高氧压,能提高菌体的固氮活性近15％,但过高的氧分压反而抑制菌体的固氮活性,此外,提高氢分压能降低棕色固氮菌菌体内的还原电位,从而达到提高菌体抗氨阻遏能力的效果。     

Clinical and microbiological features of acute enteric mixed infection caused by Hafnia alvei and rotavirus

The data obtained in the clinical and laboratory study of 72 hospitalized patients with acute enteric infection are presented. The observed outbreak was caused by H. alvei producing heat-stable enterotoxin. The role of this etiological agent is also confirmed by simultaneous occurrence of the disease after using the same foodstuff, a short incubation period, the severity of the course of the disease with pronounced symptoms of neurotoxicosis, a high detection rate of H. alvei in material taken from patients at the acute period of the disease, rapid disappearance of this agent in the period of convalescence and a pronounced rise in the titer of specific antibodies to H. alvei in the dynamics of the disease. At the same time in the feces of 8 patients rotavirus antigen was detected, which, in combination with residual catarrhal phenomena, hyperemia and granularity of the pharynx, yellow stool, was indicative of the simultaneous circulation of rotavirus among these patients.     

Late activation of interferon-induced genes IFI-54k and IFI-56k in human RH cells infected with tick-borne encephalitis virus

The genes that were induced and suppressed in human embryonic kidney cell line RH upon the infection with tick-borne encephalitis virus were studied by the method of subtractive hybridization. The expression of interferon-induced genes IFI-54K and IFI-56K in the infected cells was found to increase 50-100-fold.