[New results in computer simulation of the spread of excitation in the myocardium].

The paper presents the results from three series of simulation experiments performed by means of a realistic computer model of activation propagation in the myocardium. Simulation of two types of hypertrophy showed that hypertrophy of the ventricles without their simultaneous dilatation leaves the parameters of the cardioelectric field virtually unchanged. Change in the activation rate in the layer of elements formed by the intraventricular surface of the cavities, compared to the rate in the other elements of the heart, considerably affects the magnitude and orientation of cardiac vectors during the middle and terminal phase of activation.

Determination of hydroxypropyl-beta-cyclodextrin in plasma and urine by size-exclusion chromatography with post-column complexation.

The analytical method described here provides the appropriate sensitivity and selectivity for the determination of unlabelled hydroxypropyl-beta-cyclodextrin as a parenteral carrier in pharmaceutical formulations. The method may also be used in clinical trials evaluating the fate and pharmacokinetic profile of this compound, which was isolated from the biological matrix by solid-phase extraction with Bond Elut C18 cartridges. The lack of uniformity of the product was circumvented by the use of a size-exclusion chromatographic column.

[Suppression of coronary sclerosis in hypertensive rats by calcium channel antagonists without lowering blood pressure].

Following Skelton's procedure with unilateral adrenonephrectomy, contralateral adrenal enucleation and application of 1% NaCl with drinking fluid, normal rats develop hypertension and generalized severe arteriosclerosis within 7 weeks, experimental group I. Thereby the mean systolic blood pressure increased from 108 +/- 10 to 223 +/- 12 mm Hg, and 90 arteriosclerotic blood vessels could be counted in 100 histological sections (10 from each animal) of the hearts. Following Skelton's procedure and admixture of flunarizine with the food (40 mg flunarizine per kg for 8 weeks, started 1 week before the operation; mean plasma flunarizine value: 336 +/- 136 ng/ml at the end of the experiment), experimental group II, all rats developed hypertension too, whereby the mean systolic blood pressure increased from 109 +/- 10 to 214 +/- 16 mm Hg, but in contrast to experimental group I, only one artery with sclerosis could be observed in 100 comparable histological sections of the hearts.

Group selection of early replicators and the origin of life.

A major problem of the origin of life has been that of information integration. As Eigen (1971) has shown, a mutant distribution of RNAs replicating without the aid of a replicase cannot integrate sufficient information for the functioning of a higher-level unit utilizing several types of encoded enzymes. He proposed the hypercycle model to bridge this gap in prebiology.

The effect of Gc genotype on fasting insulin level in Dogrib Indians.

The metabolically active form of vitamin D, 1,25-(OH)2D3, is involved in the regulation of insulin level. Because the serum group-specific component (Gc) binds vitamin D, it is worth knowing whether differences in basal insulin levels are associated with Gc genotype. Such differences would warrant further investigation to clarify whether selection maintains Gc polymorphism through differential risk of Gc genotypes to diseases that involve insulin.

Dietary change and plasma glucose levels in an Amerindian population undergoing cultural transition.

Dietary change among adult Dogrib Indians of the Northwest Territories, Canada, is examined in conjunction with differences in mean glucose levels among more acculturated-less acculturated settlements. There are significant differences in the intake components derived from non-traditional foods by community and by age. However, the traditional food base is stable.

Early evolution of microtubules and undulipodia.

A critique of both autogeneous and symbiotic hypotheses for the origin of microtubules and cilia and eukaryotic flagella (undulipodia) is presented. It is proposed that spirochetes provided the ancient eukaryotic cell with microtubules twice; cytoplasmic microtubules originated from phagocytosed spirochetes whereas axopodial tubules of undulipodia were transformed from ectosymbiotic spirochetes. A role in transport for microtubules in spirochetes together with a detailed scenario by which free-living spirochetes attached as ectosymbionts and subsequently differentiated into undulipodia is outlined.

The goat blood binder of triamcinolone acetonide does not interfere with glucocorticoid receptor purification from mammary tissue.

The high affinity triamcinolone acetonide (TA) binder in goat blood was characterized in the context of our objective to purify glucocorticoid receptor from mammary tissue of the goat. A single class of binding sites was detected exhibiting an apparent equilibrium dissociation constant (Kd) of 1.3 X 10(-7) M, and the binding capacity was found to be 2200 fmol/mg serum protein.

Myasthenia gravis: long-term prognostic value of thymus lactate dehydrogenase isoenzyme pattern of hyperplastic thymus and thymoma.

Lactate dehydrogenase (LDH) isoenzyme pattern and the percent of H-subunit content were determined in the thymus of 62 patients (55 with hyperplasia, 7 with tumours) after thymectomy. An increase in LDH1 relative activity indicates that in the thymus of patients with myasthenia gravis the ratio of mature differentiated thymocytes was higher than in the thymus of control subjects. LDH isoenzyme profiles of thymus tumours were similar to those described in other neoplasms, except that thymomas with apparent predominance of epithelial cells and with minimal lymphocytic reaction exhibited a marked elevation only in LDH2 relative activity, presumably associated with the specific (secretory) function of epithelial cells.

[Postmortem decomposition of neutral lipids. Use of modern methods of analysis (HPLC, capillary GC, GC-MS and NMR) in adipocere formation].

The chemical composition of subcutaneous fats was analyzed in a corpse that had died from drowning. The skin of the cadaver examined postmortem showed different stages of adipocere. Samples from these regions were chemically compared with the fatty tissue of a person who had died recently.

Physically corrected orthogonal electrocardiographic lead systems in macaques and baboons.

The adequacy of various physically corrected electrocardiographic lead systems for lower primates was compared with the aid of physical models of the cardiac electrical field. Electrolytic tanks fashioned from plaster casts of the thorax of young adult male and female macaques and baboons were used. A dipole source situated at different points in the heart region simulated the electrical activity of the heart.

Peopling of northern North America: clues from genetic studies.

The paper reviews the archaeological evidence for the length of human occupation in N. America and raises the question whether single or multiple movements of people out of Asia into America occurred, pointing out that considerable genetic variation can occur in small isolated populations in relatively short periods of time. The entire subarctic culture area is populated by speakers of either Athapascan or Algonkian language families.

[The value of the Emit-dau system in the examination of cadaveric urine].

Randomly taken postmortem urine samples (170) were analyzed by the Emit-dau system for their barbiturate and benzodiazepine content. Of the samples, 23% and 25% were found positive for barbiturate and benzodiazepine, respectively. The percentages of the positive samples were reduced by a heating process to 9% and 11%, respectively.

Genetic differentiation in Dogrib Indians: serum protein and erythrocyte enzyme variation.

Fourteen polymorphic and 24 monomorphic serum protein and erythrocyte enzyme systems were studied in Dogrib Indians living in three villages in the Northwest Territories of Canada. New information on the subtypes of Gc is provided, as is the description of a new variant at the galactose-1-phosphate uridyl transferase (GALT) locus. Maximum European admixture in the Dogrib is 8.

Dogrib Indians of the Northwest Territories, Canada: genetic diversity and genetic relationship among subarctic Indians.

Phenotypes and gene frequencies of genes at the ABO, Rhesus, MNSs, Diego, Duffy, Kell, Kp, Kidd and P blood group systems are presented for three villages of Dogrib Indians. This population resides between Great Slave and Great Bear Lakes in the Northwest Territories of Canada. Until recently they pursued an exclusively hunting-gathering-fishing lifestyle in the subarctic forest.

The effect of pure Fusarium toxins (T-2, F-2, DAS) on the microflora of the gut and on plasma glucocorticoid levels in rat and swine.

The gut microflora and adrenal cortex hormone levels were monitored in HUNGAHYB piglets of 10-12 kg and in Wistar rats of 100-150 g body weight fed with different pure Fusarium toxins. The feeding of either T-2, T-2 + F-2 and DAS toxins at the 5 microgram/g feed level for one week resulted in the substantial increase of aerobic bacteria count of the intestine. Increase of the DAS dose to a twofold level failed to elicit dose-response and no further increases in bacterial counts were observed.