Acid-base properties of the polyene antibiotic nystatin

The acid-base properties and transformation of nystatin in water, methanol, 80 per cent ethanol, 70 per cent propanol and 70 per cent dimethylsulfoxide were studied. The data are indicative of a significant difference in the protolytic properties of the antibiotic in various solutions. Nonreversible conformative conversions of nystatin in water and methanol not connected with the loss of the antibiotic activity were observed. It is suggested that the molecule of nystatin in the above solutions could be in 3 main states, i. e. inert native and activated. The results of the study may be of use in development of the schemes for isolation of nystatin from the mycelium preparation of some of its water soluble forms.     

Determination of calcium binding sites in gas-phase small peptides by tandem mass spectrometry

Low-energy (LE) and high-energy (HE) collisionally activated decompositions (CAD) of calcium/peptide complexes of the form [M - H + Ca]+ and [M + Ca]2+ reflect the site of calcium binding in various gas-phase peptides that are models of the calcium binding site III of rabbit skeletal troponin C. The Ca2+ binding sites involve an aspartic acid, glutamic acid, and asparagine, which are in the metal-binding loops of calcium-binding proteins. Both fast atom bombardment (FAB) and electrospray ionization (ESI) were used to generate the metal/peptide complexes. When submitted to LE CAD, ESI-produced Ca2+/peptide complexes undergo fragmentations that are controlled by Ca2+ binding and provide information on the Ca2+ binding site. The LE CAD spectra are simple, indicating that Ca2+ binding involves specific oxygen ligands including acidic side chains and that only a few low-energy fragmentation channels exist. The HE CAD spectra of FAB-produced Ca2+/peptide complexes are more complex, owing to the introduction of high internal energy into the precursor ion. Interactions of the other alkaline-earth metal ions Mg2+ and Ba2+ with these peptides reveal that the ligand preferences of these metal ions are slightly different than those of Ca2+.     

Ferrireductase from Pichia guilliermondii: properties and regulation of activity and synthesis

Iranian Jews represent an ancient community with a very high degree of inbreeding. Although the community remained relatively isolated, it had strong ties with Babylonian Jewry in Iraq. Several genetic disorders have been reported to be frequent among Iranian Jews, in particular, corticosterone methyloxydase deficiency type II, polyglandular syndrome, and rimmed vacuole myopathy. Based on the data collected in our clinic, recessive and dominant deafness also appear to be frequent. Other diseases, such as beta-thalassemia, achromatopsia, colobomatous microphthalmia, Dubin-Johnson syndrome, and congenital myasthenia gravis, were frequent in both the Iranian and Iraqi Jewish communities. The place of origin of the families within Iran and the results of molecular studies suggest some reason(s) for the high frequency of these disorders among Iranian Jews. While the high frequency of some of the disorders, such as corticosterone methyloxydase deficiency type II, represents a founder effect, in other diseases (such as beta-thalassemia) it was secondary to heterozygote advantage.     

Human placenta barrier remodelling under different type of hypoxia

The stereological investigation was performed on intermediate and terminal villi of placenta obtained from each of the following conditions: high altitude (up to 2800 m), maternal anemia and EPH-gestosis. These conditions were taken to represent hypoxic, anemic and ischemic hypoxia, respectively. In each situation there was a trend for both the volume of trophoblast and stroma to be lower than in controls with accompanying increase in the volume fraction of fetal capillaries, although the differences were statistically significant only for cases of hypoxic and anemic hypoxia. The capillary diameter was higher in EPH-gestosis group. There was no evidence of "hypercapillarization" of the villi because the relative capillary length was constant in all the groups. The harmonic mean thickness in anemia and altitude groups was reduced. As a result a specific and morphometric (per 1 kg of fetal weight) diffusing capacity was maintained at the control level, but at the altitude group it was even higher. These results suggest that placenta barrier remodelling is the principal mechanism of adaptation to different forms of hypoxia.     

The dynamics of erythrocyte metabolism in severe forms of meningococcal infection and suppurative meningitis in children

In 63 children with severe meningococcal infection (MI) and meningitides of another origin red cell metabolism was studied: levels of ATP, ADP, AMP, ATP/ADP, ATP/AMP, energetic charge, 2,3-DPG, FAD, piruvate, lactate, activity of lactate dehydrogenase, piruvate kinase, glucose-6-phosphate dehydrogenase, glutatione reductase, Mg2+, Na+, K(+)-dependent ATPase. All the disease periods were characterized by combined pathobiochemical shifts of different degree typical for varying metabolic systems and correlating with the infection severity. The discussion covers pathogenetic and clinical significance of red cell metabolism shifts in patients with MI and purulent meningitides.     

Plasma marinobufagenin-like and ouabain-like immunoreactivity during saline volume expansion in anesthetized dogs

OBJECTIVES: This study investigated effects of acute plasma volume expansion on plasma levels and urinary output of two endogenous Na,K-ATPase inhibitors, marinobufagenin-like and ouabain-like immunoreactive substances. METHODS: Plasma volume was expanded for 3 h via intravenous saline infusion in three groups of anesthetized dogs--nontreated (n = 5); pretreated with rabbit antidigoxin (n = 5); and pretreated with rabbit antimouse (control) antibody (n = 4). RESULTS: Plasma marinobufagenin-like immunoreactivity increased to 11.87 +/- 3.16 nmol.l-1 (vs. 0.30 +/- 0.16 nmol.l-1) within 10 min of volume expansion, in parallel with a 15% increase in LVdP/dt, then decreased to 2.21 +/- 0.59 nmol.l-1, and in 90 min increased to 11.8 +/- 2.8 nmol.l-1, in parallel with the maximal natriuretic response. Plasma concentrations of ouabain-like immunoreactive material were increased after 90 min of saline infusion (0.019 +/- 0.004 nmol.l-1 vs. 0.139 +/- 0.056 nmol.l-1). Pretreatment of the animals with antidigoxin antibody blocked the positive inotropic and reduced natriuretic response to volume expansion, and decreased the urinary release of marinobufagenin-like, but not ouabain-like, material. CONCLUSIONS: These results show the presence of marinobufagenin-like immunoreactive substance in dog plasma and suggest that mammalian EDLF may have a bufodienolide nature. Endogenous marinobufagenin-like immunoreactive substance, which is likely to cross-react with antidigoxin antibody, is involved in the natriuretic and positive inotropic responses to plasma volume expansion.     

Methods of the use of ketorolac tromethamine in patients during the early postoperative period

An evaluation was done of respiratory failure in 149 children aged 3 to 15 presenting with funnel-shaped chest deformity (FCD). An original classification is suggested of degree of respiratory failure in FCD in children. Based on the index assessment of clinical and functional parameters an outline has been worked out for degree of respiratory failure. The criteria obtained are statistically significant; being able of giving quantitative assessment of degree of respiratory failure they can serve as control figures to be used in evaluations designed to study time course of changes in respiratory failure.     

Medico-genetic study of residents of Marii El republic: burden of hereditary diseases in four regions of the republic

A medical genetic study of Orshanskii, Morkinskii, Sovetskii, and Semurskii raions (districts) of the Marii El Republic was performed. The total number of subjects examined was 115,743. Meadow Maris and Russians accounted for the most part of the populations of the districts studied. A total of 147 families with presumably autosomal dominant (AD) pathology and 150 families with presumably autosomal recessive (AR) or X-linked pathology (270 and 169 affected persons, respectively) were revealed. Segregation analysis demonstrated a good agreement between the observed and expected segregation frequencies for both AR and AD diseases, as well as a considerable number of sporadic cases of presumably AD diseases. The incidence of hereditary diseases was estimated separately for different population groups. Significant differences in this incidence were revealed between the urban and rural, as well as between the Russian and Mari populations; the average incidence was 2.33 affected subjects per 1000 people. The incidence of AR diseases was significantly higher in Maris than in Russians (1.34 x 10(-3) and 0.82 x 10(-3), respectively). The populations studied exhibited a significant, high correlation between the incidence of AR diseases and the levels of random and local inbreeding. The incidence of X-linked recessive diseases was approximately the same as in Russian populations studied earlier. Its average value was 0.5 per 1000 men; the incidence in the Mari and Russian populations did not differ significantly. The higher AD incidence in the total population studied and the higher AR incidence in the Meadow Mari population compared to the populations studied earlier are discussed.