[Ion-exchange properties of cell walls of red seaweed Phyllophora crispa].

Research into ion-exchange properties of cell walls isolated from thallus of red seaweed Phyllophora crispa was carried out. Ion-exchange capacity and the swelling coefficient of the red alga cell walls were estimated at various pH values (from 2 to 12) and at constant ionic strength of a solution (10 mM). It was established that behavior of cell walls as ion-exchangers is caused by the presence in their matrix of two types of cation-exchange groups and amino groups. The amount of the functional group of each type was estimated, and the corresponding values of pK(a) were calculated. It can be assumed that ionogenic groups with pK(a) -5 are carboxyl groups of uronic acids, and ionogenic groups with pK(a) -7.5 are carboxyl groups of the proteins. Intervals of pH in which cation-exchange groups are ionized and can take part in exchange reactions with cations in the environment are defined. It was found that protein was a major component of cell wall polymeric matrix because its content was 36%.

[Splenic rupture in tropical malaria]. / Razryv selezenki pri tropicheskoi malarii.

The authors have observed splenic rupture in patients mainly with P. vivax malaria in 0.37% of cases. A rare case of splenic rupture in topical P. falciparum malaria is described. The patient underwent splenectomy. He was discharged from hospital after his recovery.

[Morphophysiological analysis of the formation of mechanisms of the activity-rest cycle in human ontogenesis]. / Morfofiziologicheskii analiz formirovaniia mekhanizmov tsikla aktivnost'--pokoi v ontogeneze cheloveka.

The natural behavior of normal and anencephalic fetuses at 20 to 41 weeks of the development was studied by ultrasound monitoring and continuous recording of heart rate (HR) and motor activity (MA), followed by processing and presentation on [symbol: see text]CM computer. The statistical characteristics of HR and MA changes in the anencephalic fetuses were corrected by the degree of CNS deficiency. The comparative study of 20 normal and 34 anencephalic fetuses showed: 1) when the spinal cord was present, stable HR (about 150 bpm) seems to be due to cardiac automatism and sharp decelerations unaccompanied by MA were recorded; 2) in fetuses with the medulla oblongata present showed a decrease in baseline HR up to 140 bpm, repeated pronounced decelerations and spontaneous single motor acts dissociated with the latter; 3) when a rudiment of the midbrain was present, some reductions in the amplitude of decelerations and manifestation of weak accelerations, cluster motor acts, brief episodes of the active state were revealed; 4) the quiet state was observed in fetuses with the cerebral cortex; 5) the rest-activity cycle formed with further differentiation of the cerebral cortex.

[Oxygen transport properties of the blood in acute nitrite methemoglobinemia]. / Kislorodtransportnye svoistvia krovi pri ostroi nitritnoi metgemoglobinemii.

Studies showed that a single injection of 5 mg/100 g of sodium nitrite causes the development of marked hemic hypoxia in rats, which is characterized by considerable increase of methemoglobin concentration, reduction of O2 content and O2 tension in arterial blood, sharp fall of the intensity of O2 consumption, decrease of methemoglobin concentration, and increase of the content of 2,3-diphosphoglycerate in the red cells. This is evidence of disturbed blood oxygen-transport function and the development of compensatory mechanisms directed at improving O2 supply to the tissues.

[Dynamic oxygen tension in the brain of rats under acute hypobaric hypoxia]. / Dinamika napriazheniia kisloroda v mozge krys v usloviiakh ostroi gipobaricheskoi gipoksii.

In unanesthetized rats at the "altitudes" of 4000 m (1st group) and 8000 m (2nd group), within 1.5 hrs the 1st group developed a 17-30% drop in the PO2 in 43% of cases, no changes occurred in 14% of cases, and in 43% the PO2 increased by 145-205%. In the 2nd group, the PO2 was decreased by 44-87%, on the average. The PO2 changes in the brain cortex under hypoxic conditions seems to have a phasic character as expressed by alternation of increased and decreased levels of the PO2 depending on the degree of hypoxia and induced, apparently, by systemic and local responses compensating for the lack of oxygen in the air.

[Metabolic transformation of labelled exogenous fatty acids by fungal cultures of the family Entomophthoraceae]. / Metabolicheskie prevrashcheniia ékzogennykh mechenykh zhirnykh kislot kul'turami gribov semeistva Entomophthoraceae.

Entomophthora coronata 1932 and E. conica 1716 are quite different in their fatty acid composition and the unsaturation degree of synthesized lipids. The cultures were used as models to study metabolic transformations of exogenous 14C-labeled acetic, palmitic, stearic and oleic acids as well as to compare the activities of the synthetase and desaturase enzyme complexes. The cultures were capable of transforming exogenous acetic and fatty acids into polyunsaturated arachidonic acid. E. coronata 1932 whose lipids mainly contain fatty acids with a short chain could metabolize unsaturated oleic acid to yield polyene fatty acids. However, this culture metabolized exogenous acids at a far lower rate as compared with E. conica 1716. The high content of saturated fatty acids with a short chain in the lipids might be due to the specific action of the synthetase complex and to the low activity of the desaturation enzymes. It has been demonstrated for the first time that exogenous oleic acid is converted at a high rate by the cells into arachidonic acid, a precursor of prostaglandin compounds.

[Changes in the fatty acid composition of phospholipids during the growth process of microscopic fungi of the family Entomophthoraceae]. / Izmenenie zhirnokislotnogo sostava fosfolipidov v protsesse razvitiia mikroskopicheskikh gribov semeistva Entomophthoraceae.

The fatty acid composition of phospholipids and its changes during growth of two cultures of microscopic fungi belonging to the family Entomophthoraceae have specific peculiarities. Fatty acids in the composition of phospholipids contain from 10 to 20 carbon atoms in the chain; unsaturated fatty acids prevail among them, and constitute about 60% in the phospholipids of Ent. coronata 1932 and about 70% in the phospholipids of Ent. conica 1716. The content of arachidonic acid in the phospholipids of the both cultures is high (up to 17%). The fatty lipids of phospholipids are actively involved in metabolism in the process of the fungal growth, particularly in Ent. coronata 1932 which is characterized by a higher level of metabolism. The total degree of unsaturation of phospholipids changes only slightly during the growth of the two cultures.

[Age changes in the lipid fatty acid makeup of cultures of the family Entomophthoraceae]. / Bozrastnye izmeneniia zhirnokislotnogo sostava lipidov u nekotorykh kul'tur semeistva Entomophthoraceae.

The rate of biosynthesis of lipids and their fatty acid composition were studied in four cultures of microscopic fungi belonging to the family Entomophthoraceae in the course of their growth. The cultures synthesized from 23% to 43% of lipids. The lipids comprised fatty acids containing from 9 to 24 carbon atoms in the chain. The lipids differed in their fatty acid composition and the degree of saturation: unsaturated fatty acids (50-60%) prevailed in the lipids of Ent. conica 1716, Ent. thaxteriana 1711 and 1931, while saturated fatty acids (70%) predominated in the lipids of Ent. coronata 1710. Isomers with different position of double bonds were found among C18-unsaturated fatty acids (two octadecenic, three octadecadienic and two octadecatrienic acids). Branched fatty acids were detected in low amounts in the lipids. The character of changes in the fatty acid composition of lipids was different in the process of the cultural growth.

[Intrauterine destruction of the brain by molds]. / Vnutriutrobnye porazheniia golovnogo mozga plesnevymi gribami

Pathohistological changes in the brain of 15 fetuses and newborns caused by intrauterine damage with mouldy fungi, identified according to their morphological characteristics as aspergillas, are described. The predominant localization of the mycotic foci was the periventricular zone of the lateral ventricles. Special attention is given to grave lesions of the brain's vessels and the ependyma of the lateral ventricles. A collation of pathomorphological data with the results of clinical examination of the mothers and children was carried out.