Features of 80S mammalian ribosome and its subunits

It is generally believed that basic features of ribosomal functions are universally valid, but a systematic test still stands out for higher eukaryotic 80S ribosomes. Here we report: (i) differences in tRNA and mRNA binding capabilities of eukaryotic and bacterial ribosomes and their subunits. Eukaryotic 40S subunits bind mRNA exclusively in the presence of cognate tRNA, whereas bacterial 30S do bind mRNA already in the absence of tRNA. 80S ribosomes bind mRNA efficiently in the absence of tRNA. In contrast, bacterial 70S interact with mRNA more productively in the presence rather than in the absence of tRNA. (ii) States of initiation (Pi), pre-translocation (PRE) and post-translocation (POST) of the ribosome were checked and no significant functional differences to the prokaryotic counterpart were observed including the reciprocal linkage between A and E sites. (iii) Eukaryotic ribosomes bind tetracycline with an affinity 15 times lower than that of bacterial ribosomes (Kd 30 μM and 1–2 μM, respectively). The drug does not effect enzymatic A-site occupation of 80S ribosomes in contrast to non-enzymatic tRNA binding to the A-site. Both observations explain the relative resistance of eukaryotic ribosomes to this antibiotic

ВЛИЯНИЕ ЙОДСОДЕРЖАЩЕГО ПРЕПАРАТА «ЙОДОМАРИН» НА ВОСПРОИЗВОДИТЕЛЬНУЮ СПОСОБНОСТЬ И МОЛОЧНУЮ ПРОДУКТИВНОСТЬ КОРОВ

The influence of the new iodine containing preparation Iodomarin on the reproductive capacity and lactation performance of cows has been studied. It’s established that the use of 750 mkg of Iodomarin per capita a day improves the reproductive capacity of cows. It is reflected in the reduction of the labour length, a quicker separation of the placenta after calving, the reduction of the service time, and the increase of the lactation performance.Изучено влияние нового йодсодержащего препарата «Йодомарин» на воспроизводительную способность и молочную продуктивность коров. Установлено, что использование для коров сухостойного периода препарата «Йодомарин» в количестве 750 мкг на голову в сутки способствует улучшению воспроизводительной способности коров, что проявляется в сокращении продолжительности родов, более быстром отделении последа после отела, сокращении сервис-периода, а также повышению молочной продуктивности

Entamoeba lysyl-tRNA Synthetase Contains a Cytokine-Like Domain with Chemokine Activity towards Human Endothelial Cells

Immunological pressure encountered by protozoan parasites drives the selection of strategies to modulate or avoid the immune responses of their hosts. Here we show that the parasite Entamoeba histolytica has evolved a chemokine that mimics the sequence, structure, and function of the human cytokine HsEMAPII (Homo sapiens endothelial monocyte activating polypeptide II). This Entamoeba EMAPII-like polypeptide (EELP) is translated as a domain attached to two different aminoacyl-tRNA synthetases (aaRS) that are overexpressed when parasites are exposed to inflammatory signals. EELP is dispensable for the tRNA aminoacylation activity of the enzymes that harbor it, and it is cleaved from them by Entamoeba proteases to generate a standalone cytokine. Isolated EELP acts as a chemoattractant for human cells, but its cell specificity is different from that of HsEMAPII. We show that cell specificity differences between HsEMAPII and EELP can be swapped by site directed mutagenesis of only two residues in the cytokines' signal sequence. Thus, Entamoeba has evolved a functional mimic of an aaRS-associated human cytokine with modified cell specificity

Effect of Systemic Hypertension With Versus Without Left Ventricular Hypertrophy on the Progression of Atrial Fibrillation (from the Euro Heart Survey).

Hypertension is a risk factor for both progression of atrial fibrillation (AF) and development of AF-related complications, that is major adverse cardiac and cerebrovascular events (MACCE). It is unknown whether left ventricular hypertrophy (LVH) as a consequence of hypertension is also a risk factor for both these end points. We aimed to assess this in low-risk AF patients, also assessing gender-related differences. We included 799 patients from the Euro Heart Survey with nonvalvular AF and a baseline echocardiogram. Patients with and without hypertension were included. End points after 1 year were occurrence of AF progression, that is paroxysmal AF becoming persistent and/or permanent AF, and MACCE. Echocardiographic LVH was present in 33% of 379 hypertensive patients. AF progression after 1 year occurred in 10.2% of 373 patients with rhythm follow-up. In hypertensive patients with LVH, AF progression occurred more frequently as compared with hypertensive patients without LVH (23.3% vs 8.8%, p = 0.011). In hypertensive AF patients, LVH was the most important multivariably adjusted determinant of AF progression on multivariable logistic regression (odds ratio 4.84, 95% confidence interval 1.70 to 13.78, p = 0.003). This effect was only seen in male patients (27.5% vs 5.8%, p = 0.002), while in female hypertensive patients, no differences were found in AF progression rates regarding the presence or absence of LVH (15.2% vs 15.0%, p = 0.999). No differences were seen in MACCE for hypertensive patients with and without LVH. In conclusion, in men with hypertension, LVH is associated with AF progression. This association seems to be absent in hypertensive women

Progression From Paroxysmal to Persistent Atrial Fibrillation. Clinical Correlates and Prognosis

Objectives: We investigated clinical correlates of atrial fibrillation (AF) progression and evaluated the prognosis of patients demonstrating AF progression in a large population. Background: Progression of paroxysmal AF to more sustained forms is frequently seen. However, not all patients will progress to persistent AF. Methods: We included 1,219 patients with paroxysmal AF who participated in the Euro Heart Survey on AF and had a known rhythm status at follow-up. Patients who experienced AF progression after 1 year of follow-up were identified. Results: Progression of AF occurred in 178 (15%) patients. Multivariate analysis showed that heart failure, age, previous transient ischemic attack or stroke, chronic obstructive pulmonary disease, and hypertension were the only independent predictors of AF progression. Using the regression coefficient as a benchmark, we calculated the HATCH score. Nearly 50% of the patients with a HATCH score >5 progressed to persistent AF compared with only 6% of the patients with a HATCH score of 0. During follow-up, patients with AF progression were more often admitted to the hospital and had more major adverse cardiovascular events. Conclusions: A substantial number of patients progress to sustained AF within 1 year. The clinical outcome of these patients regarding hospital admissions and major adverse cardiovascular events was worse compared with patients demonstrating no AF progression. Factors known to cause atrial structural remodeling (age and underlying heart disease) were independent predictors of AF progression. The HATCH score may help to identify patients who are likely to progress to sustained forms of AF in the near future. \ua9 2010 American College of Cardiology Foundation

Current issues in the management of soft tissues of the oral vestibule before orthodontic treatment

Orthodontic treatment tasks include requirements not only forproper teeth alignment and optimal jaw relationships in thesagittal and vertical planes with the maximum of occlusal contactsbut also for healthy periodontal tissues upon completionof orthodontic treatment. Often, certain occlusal anomaliesaffect the surrounding soft tissues. In this situation, the orthodontistrealizes that not until the periodontal problem isresolved can the orthodontic treatment begin. Soft tissueanomalies include epithelial cords that make the periostealattachments extremely thin, may prevent tooth eruption, orcause multiple gingival recessions. The shallow oral vestibulealso adversely affects the position of the incisors, especiallyin the lower jaw. In such cases, incisors should not be movedusing fixed orthodontic appliances, since this will cause thinningof the attached gingiva in the cervical margins of theteeth, or exacerbate the existing gingival recessions, whichin turn will lead to root sensitivity. If a patient already exhibitsmultiple or severely expressed single gingival recessions, wesuggest their closure by surgery as a primary intervention beforeorthodontic treatment with fixed appliances or aligners,which will continuously traumatize the thin edge of attachedgingiva. In this article, we will address the necessary periodontalprocedures that orthodontists should consider beforeinitiating orthodontic correction to avoid irreversible degradationof the soft tissues of the oral cavity, periodontal tissues

Current issues in the management of soft tissues of the oral vestibule before orthodontic treatment

Orthodontic treatment tasks include requirements not only forproper teeth alignment and optimal jaw relationships in thesagittal and vertical planes with the maximum of occlusal contactsbut also for healthy periodontal tissues upon completionof orthodontic treatment. Often, certain occlusal anomaliesaffect the surrounding soft tissues. In this situation, the orthodontistrealizes that not until the periodontal problem isresolved can the orthodontic treatment begin. Soft tissueanomalies include epithelial cords that make the periostealattachments extremely thin, may prevent tooth eruption, orcause multiple gingival recessions. The shallow oral vestibulealso adversely affects the position of the incisors, especiallyin the lower jaw. In such cases, incisors should not be movedusing fixed orthodontic appliances, since this will cause thinningof the attached gingiva in the cervical margins of theteeth, or exacerbate the existing gingival recessions, whichin turn will lead to root sensitivity. If a patient already exhibitsmultiple or severely expressed single gingival recessions, wesuggest their closure by surgery as a primary intervention beforeorthodontic treatment with fixed appliances or aligners,which will continuously traumatize the thin edge of attachedgingiva. In this article, we will address the necessary periodontalprocedures that orthodontists should consider beforeinitiating orthodontic correction to avoid irreversible degradationof the soft tissues of the oral cavity, periodontal tissues