A challenging future

The following article is a slightly condensed version of a talk given at The Metallurgical Society’s Extractive Metallurgy Division Luncheon, delivered in New York at the Waldorf Astoria on February 28, 1968, as part of the AIME Annual Meeting.     

Unstable angina: long-term dynamic observation based on the data from Holter ECG monitoring

The choice of treatment of patients with unstable angina is one of the most important problems in cardiology. Establishment of its tactics is necessary both in hospital and in posthospital periods. 24-hour Holter monitoring is a safe and informative method which makes it possible to objectivize the state in such category of patients. In order to study the structure of ischemia and arrhythmias this approach was used in 50 patients with unstable angina at the first admission twice and also twice within the first year of follow-up. It was shown that stabilization which was achieved during the first hospitalization was retained in 58.2% during 1 year. In other cases increases of frequency, duration and significance of ischemia were observed. In the global structure of myocardial ischemia, silent ischemia composed 56-65%.     

A trial of the clinical use of a new method of electrosleep

A novel device and technique of interference electric sleep therapy have been developed and tried in 125 children and 324 adults with different diseases. The highest clinical response, especially in children, was achieved on Elson unit.     

Platelet production time in surgery

A protein factor from the d greater than 1.25 g/ml plasma fraction controls the transfer of cholesterol esters between high density lipoproteins and very low density lipoproteins. This transfer is time-dependent, and follows saturation kinetics relative to the concentration ratio of acceptor to donor lipoproteins. Although the process is reversible, the transfer rates are faster from high density to very low density lipoproteins and result in a net increase of cholesterol esters in the very low density lipoproteins. Under the same conditions, there is also a net mass transfer of cholesterol esters from high density lipoproteins to chylomicrons. This constitutes the first demonstration of cholesterol ester mass transfer between isolated lipoproteins and contrasts with the equilibrium of cholesterol esters between HDL and LDL which we previously demonstrated [4]. The apparent maximum transfer rate of cholesterol esters from high density to very low density lipoproteins was calculated to be about 80 nmoles cholesterol esters/h/ml plasma, which is very similar to the initial rate of reaction of lecithin:cholesterol acyltransferase in plasma. It is concluded that cholesterol ester formation in high density lipoproteins and their transfer to triglyceride-rich lipoproteins may be closely coupled.     

Influence of phenobarbital on the immunodepressive action of antitumor substances

In the experiments on mice, immunized by mutton erythrocytes, the authors have studied the effect of phenobarbital, in the doses activating drug-metabolizing hepatic systems, on immunodepressive action of imurane, 6-mercaptopurine and cyclophosphane. It has been found that phenobarbital eliminates the immunodepression and reduces considerably the toxicity of the mentioned cytostatics. Under these conditions imurane and 6-mercaptopurine in certain doses render an immunostimulative instead of immunodepressive effect.     

Pathogenesis of the low cardiac output syndrome in postreanimation states

Functional reserves of the cardiovascular system during sharp depression of the cardiac output in the postreanimation period after 15-minute cardiac arrest were studied in experiments on dogs (by loading with different fluid volumes). Acute hypervolemia did not produce any circulatory decompensation. Reinforcement of venous return and changes in the peripheral circulation due to polyglucine loading augmented the CVP temporarily, and produced a stable increase of the AP, of the cardiac output, systolic volume, the work of the left cardiac ventricle and of the total oxygen consumption by the organism. Meanwhile there was a decrease of the peripheral vascular resistance. In model experiments on dogs, which sustained 20-minute isolated compression ischemia the syndrome of low cardiac output developed too. This indicated the relation of this phenomenon to the disorders in the neuro-humoral regulation of blood circulation.     

Synthesis and properties of covalently-closed DNA duplexes containing pyrophosphate and and substituted pyrophosphate internucleotide groups

A new method for the efficient synthesis of covalently closed DNA duplexes (DNA dumbbells) and the introduction of pyrophosphate and substituted pyrophosphate internucleotide groups into their structure is proposed. The method is based on chemical ligation in DNA duplexes that are formed by a polynucleotide the ends of which are brought together due to the introduction of the minihairpin structure [sequence: see text]. DNA dumbbells containing a pyrophosphate (substituted pyrophosphate) group result from the interaction as being between the 3'-terminal phosphate (methylphosphate) group of the polynucleotide and the 5'-terminal phosphate group of deoxyguanosine of the minihairpin sequence, which flanks the polynucleotide from the 5' end. 1-Ethyl-3-(3'-dimethylaminopropyl) carbodiimide was used as a condensing agent. The yield of covalently closed 42-mer DNA duplexes containing a pyrophosphate group was 98%, that of duplexes with a substituted pyrophosphate group was 25%. The reactivity of the substituted pyrophosphate group incorporated into DNA dumbbells was studied. It is shown that the group efficiently interacts with nucleophiles in an aqueous medium at pH 8.0.