GAMETOPHYTE DEFECTIVE 1, a Putative Subunit of RNases P/MRP, Is Essential for Female Gametogenesis and Male Competence in Arabidopsis

RNA biogenesis, including biosynthesis and maturation of rRNA, tRNA and mRNA, is a fundamental process that is critical for cell growth, division and differentiation. Previous studies showed that mutations in components involved in RNA biogenesis resulted in abnormalities in gametophyte and leaf development in Arabidopsis. In eukaryotes, RNases P/MRP (RNase mitochondrial RNA processing) are important ribonucleases that are responsible for processing of tRNA, and transcription of small non-coding RNAs. Here we report that Gametophyte Defective 1 (GAF1), a gene encoding a predicted protein subunit of RNases P/MRP, AtRPP30, plays a role in female gametophyte development and male competence. Embryo sacs were arrested at stages ranging from FG1 to FG7 in gaf1 mutant, suggesting that the progression of the gametophytic division during female gametogenesis was impaired in gaf1 mutant. In contrast, pollen development was not affected in gaf1. However, the fitness of the mutant pollen tube was weaker than that of the wild-type, leading to reduced transmission through the male gametes. GAF1 is featured as a typical RPP30 domain protein and interacts physically with AtPOP5, a homologue of RNases P/MRP subunit POP5 of yeast. Together, our data suggest that components of the RNases P/MRP family, such as RPP30, play important roles in gametophyte development and function in plants

Palaeobiology of latest Ediacaran phosphorites from the upper Khesen Formation, Khuvsgul Group, northern Mongolia

Microfossil assemblages that include large acritarchs with complex processes, known as Doushantuo-Pertatataka-type acritarchs, are recovered from early Ediacaran successions globally. They are commonly found in shale and chert lithologies, but their diversity and palaeobiological significance is greatest when they are phosphatized. The best-known examples are from the Doushantuo Formation, South China, which preserves over 60 taxa including possible embryonic forms which may represent the oldest fossil animals. Fossils have only been recorded in four Ediacaran phosphorite deposits. Here we report the fifth such occurrence, from phosphorites of the upper Khesen Formation, Khuvsgul Group, northern Mongolia, where preservation rivals that in the Doushantuo Formation. The assemblage includes the likely cyanobacteria Obruchevella delicata, O. magna, O. parvissima and O. valdaica, as well as various Siphonophycus filaments, the possible alga Archaeophycus yunnanensis, and the Doushantuo-Pertatataka-type acritarchs Appendisphaera grandis, A. fragilis, A. tenuis, Cavaspina basiconica, Variomargosphaeridium gracile and V. aculeiparvum, sp. nov. The phosphorites also preserve the multicellular embryo-like taxon Megasphaera, which is represented by M. minuscula sp. nov. and potentially by M. puncticulosa. Geological and chemostratigraphical data suggest a latest Ediacaran age for the Khesen assemblage, immediately prior to the Proterozoic–Phanerozoic boundary. Thus, this is the youngest Doushantuo-Pertatataka-type microfossil assemblage yet described. It extends the range of Appendisphaera, Cavaspina, Megasphaera and Variomargosphaeridium upward by tens of millions of years. The assemblage adds to a growing database of Ediacaran fossils and emphasizes the importance of Mongolian strata to understanding the transition from a broadly microbial Proterozoic Eon to a Phanerozoic Eon where macroscopic animals acted as geobiological agents

Anaphylaxis in children: problems and solutions

Since the term “anaphylaxis” has been invented, there are multiple changes in the views on both pathophysiology and the diagnostic and therapeutic aspects of this disease. There have been currently adopted a number of international documents containing principles of anaphylaxis verification and treatment. However, the experts’ views differ, and some disagreements and problems of anaphylactic reactions remain relevant, especially in pediatric patients. The article discusses current issues and possible ways of treatment of anaphylaxis in children

Rheological blood properties in psoriatic arthritis: relationship with inflammation and cardiovascular risk

Objective. To study possibility of using blood rheological parameters as markers of inflammation and cardiovascular risk (CVR) in pts with psoriatic arthritis (PA). Material and methods. 130 pts (51 male and 79 female) with PA aged from 39 to 48 years (mean age 43 years) without clinical signs of coronary heart disease (CHD) and stroke were included. Duration of PA varied from 2 months to 42 years (mean 7 years), duration of psoriasis (PS) – from 5,5 to 26 years (mean 15 years). Main measures of erythrocyte aggregation (EA) including Kt (c-1) – total speed of erythrocytes aggregates formation, T (c) – time of linear erythrocytes aggregates formation, I2,5 [%] – parameter characterizing durability of most large erythrocytes aggregates, β (c-1) – hydrodynamic durability of erythrocytes aggregates were evaluated in erythroaggregometer by registration of intensity of inverse light scattering from blood sample. PA activity was measured with DAS4. CHD development risk score was determined considering traditional CVR factors – age, total cholesterol (TCH) and high density lipoproteins (HDLP) level, systolic blood pressure (SBP), presence of diabetes, smoking. Serum C-reactive protein (CRP) and fibrinogen concentration was measured with standard methods. Correlation analysis was performed with Spearman range correlation coefficient (R), Mann-Whitney (U) test was used for groups comparison and p<0,05 was considered as statistically significant level. Results. EA disturbances corresponding to 2nd stage of severity were present in all pts with PA. Significant correlation between EA parameters (T , Kt, I2,5, β) and DAS4 (R=-0,32/0,32/0,33/0,25, p<0,001) as well as significant correlation of all EA parameters (T , Kt, I2,5, β) with laboratory inflammation markers: CRP (R=-0,37/0,41/0,46/0,32), ESR (R=-0,34/0,35/0,42/0,26) and most strong – with fibrinogen (R=-0,55/0,55/0,49/0,32) were revealed. Significant correlations of all EA parameters and fibrinogen with CVR level was found in all pts (R=-0,31/0,35/0,23/0,22, p<0,001). In women relationship between EA parameters, fibrinogen and CVR level was stronger (R=-0,42/0,41/0,40/0,27). In men correlation between EA parameters, fibrinogen and CVR was not found. Conclusion. EA parameters in PA are biomarkers of inflammation and CVR

Association between the activity of enzyme CYP3A4 and profile of efficacy and safety of haloperidol in patiens with alcohol addiction

In case of patients with alcohol addiction haloperidol is used to control the exacerbation of the addiction, but the empirical dose selection of haloperidol often results in adverse side effects. Microsomal isozyme cytochrome P450 3A4, the activity of which has wide variability, takes part in biotransformation of haloperidol. The study involved 35 men with alcohol addiction. The efficacy and safety of haloperidol was evaluated by international psychometric scales. The activity of CYP3A4 was evaluated by determination endogenous substrate of this isoenzyme and its metabolite in urine - (the ratio of 6-beta-hydrocortizol/corizol). The study revealed a statistically significant patterns between the activity of CYP3A4 and the efficacy and safety of haloperidol

Association between the activity of enzyme CYP3A4 and profile of efficacy and safety of haloperidol in patiens with alcohol addiction

In case of patients with alcohol addiction haloperidol is used to control the exacerbation of the addiction, but the empirical dose selection of haloperidol often results in adverse side effects. Microsomal isozyme cytochrome P450 3A4, the activity of which has wide variability, takes part in biotransformation of haloperidol. The study involved 35 men with alcohol addiction. The efficacy and safety of haloperidol was evaluated by international psychometric scales. The activity of CYP3A4 was evaluated by determination endogenous substrate of this isoenzyme and its metabolite in urine - (the ratio of 6-beta-hydrocortizol/corizol). The study revealed a statistically significant patterns between the activity of CYP3A4 and the efficacy and safety of haloperidol