A new approach to artificial and modified proteins: theory-based design, synthesis in a cell-free system and fast testing of structural properties by radiolabels

A novel approach to the creation of artificial and modifiedproteins has been elaborated. The approach includes a sequencedesign based on the molecular theory of protein secondary structureand folding patterns, gene expression in a cell-free systemand testing of structural properties of the synthesized polypeptidesat a nanogram level using radiolabelled chains. The approachhas been applied to a new synthetic protein albebetin whichhas been designed to form a 3-D fold which does not contradictany structural rule but has been never observed up to now innatural proteins. Using size-exclusion chromatography, urea-gradientelectrophoresis and limited proteolysis of a radiolabelled chain,it has been shown that the artificial protein is nearly as compactas natural proteins, cooperatively unfolds at high urea concentrationsand has some structural features of a definite structure consistentwith the designed one. As albebetin has been designed as consistingof two structural repeats, a ‘halfalbebetin’ (oneof these repeats) has also been synthesized and studied. Itwas shown that ‘half-albebetin’ is also compact     

Effects of ouabain on the isolated human uteroplacental vasculature

OBJECTIVE: We sought to describe the effects of ouabain on the human uteroplacental vasculature. STUDY DESIGN: Stem villous vessels and intramyometrial arteries isolated from placental and myometrial biopsy specimens at term were mounted in organ baths. Moreover, isolated human placental cotyledons were perfused. RESULTS: Contractions induced by the thromboxane A2 analog U46619 were unaffected by pretreatment with ouabain 10(-10) to 10(-6) mol/L. In fetal vessels nitric oxide (10(-8) to 3 x 10(-5) mol/L) induced relaxation of vascular tonus induced by U46619 and potassium. This relaxation was inhibited by pretreatment with ouabain 10(-7) to 10(-6) mol/L. These associations were unaffected by removal of the endothelium. In maternal arteries ouabain (10(-6) mol/L) failed to significantly affect nitric oxide-induced relaxation. Ouabain (10(-9) mol/L) significantly affected pressure-flow relationships in perfused cotyledons. CONCLUSIONS: Ouabain impairs nitric oxide-induced relaxation of human stem villous arteries and veins, which may explain the changes induced by therapeutically relevant concentrations of the drug on pressure-flow relationships in the perfused cotyledon. Thus treatment with cardiac glycosides in pregnancy may impair uteroplacental blood flow.     

Gold Mining by Geotechnological Methods. Part I: Technological Solutions

The general characteristic for geotechnological methods of metal mining and their advantages over traditional ones are presented. A review is given for the principal technological solutions used in different countries in mining gold by geotechnological methods.     

Hemosorption in the prevention of severe forms of hemolytic disease of the newborn in rhesus sensitization

A total of 164 hemoperfusions were administered to 60 pregnant patients with Rh sensitization and a history of perinatal death of the newborns from hemolytic disease. Hemoperfusion was found to decelerate the progress of hemolytic disease of the newborns promoting delivery of babies with more benign forms of the disease. The method efficacy was 76%. Dynamic follow-up of fetal functional status over the course of hemosorption treatment by examinations of biophysical profiles and ultrasonic dopplerometry has shown no negative effects of this treatment modality on fetal status.     

Costello syndrome: two cases with embryonal rhabdomyosarcoma

Costello syndrome is a well delineated mental retardation syndrome of unknown aetiology in which the occurrence of benign tumours, especially papillomata, is recognised. We report two children in whom the diagnosis of Costello syndrome was made in the first months of life, who both developed a retroperitoneal embryonal rhabdomyosarcoma. Although not previously reported, the occurrence of this relatively uncommon childhood tumour in two girls with Costello syndrome suggests that an increased risk of malignancy may be part of this condition. The genetic basis of this susceptibility requires further clarification.