[Age-related changes in blood concentration of hypothalamic-pituitary-adrenal axis hormones, their central and peripheral regulators in healthy men].

UNLABELLED: We studied concentrations of cortisol, its precursors and active form in human blood and relation to the changes in concentration of central and peripheral hormonal regulators (total 36 parameters) in healthy male volunteers aged 18-72 y.o. The study demonstrated a significant decrease in blood concentrations of unutilazed cortisol precursors (pregnenolone and progesterone) with advanced age accompanied by maintenance of total and free cortisol concentrations. We found age-related decrease in ACTH level that is a known hypophysial stimulant of cortisol and cortisol precursor synthesis in adrenal glands. Cortisol and ACTH levels in study population had different correlation behavior in relation to central and peripheral regulators for hormonal axes. CONCLUSION: cortisol level remains stable with advanced age in males despite the decrease in steroidogenic activity and blood ACTH level. This may be due to the imbalance in the regulation of cortisol and ACTH production by central and peripheral regulators especially by hormones of reproductive and somatotrophic axes.

[Age-dependent changes in the concentration of active sex steroids, their precursors, metabolites, and regulating agents in male blood].

Blood concentrations of hormone-inactive and active sex-steroid metabolites and their precursors were measured, taking into account changes in protein-peptide hormones that control the reproductive axis (in a total of 14 parameters) in men in the 18- to 72-year-old age interval. A significant decrease in the blood concentration of unutilized precursors of active sex steroids (pregnenolone, progesterone, dehydroepiandrosterone, and its sulfate), unbound testosterone, androstenedione (an inactive metabolite of testosterone), and an active metabolite, 5alpha-dihydrotestosterone was determined after the age of 35. However, the level of total testosterone and of estradiol (another active metabolite of testosterone) remained constant. The systems regulating the production of active sex steroids resisted a higher load, causing the luteinizing and follicle-stimulating hypophyseal hormones and activin of steroidogenic glands to increase and correlate positively with age; these hormones correlated negatively with certain sex steroids that realize negative feedback. A decrease in the level of adrenocorticotropic hypophyseal hormone with age suggests a more substantial role for adrenal glands as compared to that of testicles in reducing the blood concentration of active sex steroids. In general, despite the reduced activity of steroidogenic glands in 60- to 70-year-old men, their testosterone and estradiol concentrations remain unchanged, due to coordinated growth in the concentration of luteinizing and follicle-stimulating hypophyseal hormones, and to the activin of steroidogenic glands, which stimulated sex steroid biosynthesis. At the same time, the androgen effect was inhibited as a result of reduced levels of unbound testosterone and 5alpha-dihydrotestosterone.

[Metabolic syndrome diagnosis in patients with arterial hypertension and obesity].

AIM: To develop a universal method of metabolic syndrome (MS) diagnosis which is valid irrespective of the version in patients with documented arterial hypertension (AH) and obesity. MATERIAL AND METHODS: MS was diagnosed according to two versions (WHO and ATPIII) in 517 males and 1041 females aged 20 to 75 years. All the patients had documented obesity and hypertension. RESULTS: Two versions used (WHO and ATPIII) provided the same results only in 44% patients: MS was confirmed in 16% and rejected in 28%. The rest 56% patients had MS only by one of the versions. A computer program has been created for making decision about MS presence in obese patients with hypertension. CONCLUSION: A diagnostic rule has been elaborated for MS diagnosis by associated disorders with accuracy of 94% even in the absence of information about such key components of MS as HDLP and triglycerides.

[An expert system to support diagnostic decision making by a neonatologist]. / Ekspertnaia sistema podderzhki priniatiia diagnosticheskikh reshenii vrachom-neonatologom.

An "NATEX" expert system has been designed, which is intended to support a neonatologist's diagnostic decision making at the first stage of neonatal nursing. While designing the expert system, the authors used the shell "REPROCODE" wherein medical knowledge is presented as hierarchical semantic threshold network with shared attribute space. The designed system is realized on the basis of an IBM PC XT/AT, its operation requires only the processor 80286 and the operating system MS DOS 3.0 or higher. The "NATEX" expert system is employed to diagnose major syndromes of neonatal diseases. The knowledge base of the "NATEX" system has an account of 33 syndromes of neonatal diseases and, with various forms of severities borne in mind, the total number of diagnosed conditions in a baby is 63. In terms of content, it covers all major syndromes assessing the vital systems of the neonatal body and their occurring processes. The total number of symptoms which are necessary and sufficient for making a diagnostic decision as realization of either syndromes is 700.