[Place of inhibin B investigation in clinical andrological praxis]. / Význam stanovování inhibinu B v klinické andrologické praxi.

Inhibin B is a gonadal dimeric peptide, produced in men in testicular Sertolli cells. Inhibin B blood level knowledge can be a useful tool in the management of difficult diagnostic problems, such as ambiguous genitalia, the distinction between cryptorchidism and anorchidism and the hypogonadotrophic hypogonadism/delayed puberty differential diagnosis. Inhibin B measurements can help in gonadal dysgenesis evaluation, androgen insensitivity management and also in the diagnosis of some gonadal tumors. In adult men, inhibin B evaluation is helpful in the investigation of male infertility, especially in the judgment of the prognosis of testicular biopsy in in-vitro fertilization programs. Although commercial kits for inhibin B measurement are available at present, its evaluation is accessible in the Czech Republic for the time being in only very limited number of laboratory centers.

[Male hormonal contraception]. / Muzská hormonální antikoncepce.

Human reproduction is a complex phenomenon remaining at the center of interest of many medical and extra-medical disciplines and the search for new contraceptive methods is an important part of research effort. The development of effective forms of male hormonal contraception (MHC) is one of the priorities of the World Health Organization (WHO Task Force on Methods of Regulation of Male Fertility). The principle of MHC consists in the suppression of spermatogenesis while preserving all other functional aspects of the male glands (especially the sexual functions, bone metabolism and lean muscle mass). It is possible to stop spermatogenesis by blocking gonadotrophin (FSH and LH) secretion by testosterone administration (isolated or in combination with other hormones). The currently existing variants of MHC are based on testosterone application (which has in the same time the role of substitutive treatment--the so-called androgen "add-back") either in monotherapy (oral, intramuscular, transdermal and subcutaneous form) or in combination with various progestins (levonorgestrel, norethisterone, desogestrel, eronogestrel, medroxyprogesterone), antiandrogens or GnRH analogues. The most promising, at present, seem to be the methods which use a combination of depot testosterone preparations with long-acting progestins. To what extent will the role of MHC be important in the future--this can only be judged after establishing their effectiveness, full reversibility, safe application, acceptability, and financial accessibility in clinical practice.

Do DHEA/DHEAS play a protective role in coronary heart disease?

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS), the major androgens secreted by human adrenal glands, were suggested to play a protective role in the pathogenesis of atherosclerosis and coronary heart disease. On the basis of a critical review of all existing studies we concluded that 1) there is no evidence of a protective role of DHEA and DHEAS in women, and 2) men with low plasma DHEA and DHEAS levels can be considered as beings at risk of developing a fatal cardiovascular event. These androgens can interfere with atherogenic process by several mechanisms. They influence enzymes such as glucoso-6-phosphate dehydrogenase, which can modify the lipid spectrum. Furthermore, they can inhibit human platelet aggregation, enhance fibrinolysis, slow down cell proliferation and reduce plasma levels of plasminogen activator inhibitor type 1 and tissue plasminogen activator antigen. We suggest that all these DHEA(S) actions are dependent on sex hormone metabolic pathways. There are still insufficient data to advise DHEA supplementation in elderly men, but this type of hormone replacement therapy merits further studies.

[The Internet and medicine. I. Historical development, current organizational structure, E-mail, the Web and discussion forums]. / Internet a medicína. I. Historický vývoj, soucasná organizacní struktura, e-mail, web, multimédia a diskusní fóra.

The authors present an account on the historical development of the most important contemporary information network INTERNET from its beginnings in the sixties to the present time. They explain the historical circumstances of its development, elucidate its character and describe the creation and fusion of all main information networks during the seventies, eighties and nineties up to their present shape. They deal with the contemporary organizational structure of INTERNET, safety and reliability of transmitted information and values of its services. They explain terms like E-mail, Web, multimedia and discussion fora and describe how to join this gigantic information network in practice.

[The Internet and medicine. II. Present status and perspectives in the use of the Internet in Medicine]. / Internet a medicína. II. Soucasnost a perspektivy vyuzití internetu v medicíne.

The authors present an account of all contemporary possibilities to use Internet in medicine. They summarize the advantages and disadvantages of electronic mail (E-mail) and give a list of services available via the World Wide WEb: the possibility to inspect more than seventy medical journals, consult books and specialized databases and acquire further medical training. They demonstrate actual possibilities how to use Internet in everyday medical practice. The authors present also data indicating the general scope of Internet and its application in medical sciences. In the conclusion the authors reflect on the future application of Internet and point out some risks which may interfere with or threaten in the near and remote future the use of Internet.

[Thyroglobulin and microsome autoantibodies and their clinical significance in adult type I diabetics]. / Výskyt protilátek proti tyreoglobulinu a proti mikrosomum u dospelých diabetiku I. typu a jejich mozný klinický význam.

In 34 patients with type 1 diabetes manifested in postadolescent age (mean age at time of diagnosis 25 years, 18 women and 16 men) after the establishment of the diagnosis perspectively the presence of antibodies against thyroglobulin and the microsomal fraction and their relation to affection of the thyroid gland was investigated. During an investigation of 20% of the patients the authors provided repeatedly evidence of the presence of both antibodies, in 23% repeatedly only against microsomes. In 21% some antibodies were detected only once. In the course of the investigation in 65% of the patients thyroid antibodies were found. The clinically most serious affection of the thyroid gland (from the sonographic an functional aspect) was found in groups 1 an 2, while in groups 3 and 4 in the majority of patients the thyroid gland was not affected. A different pathogenesis of the disease in the above groups is suggested in the areas of DR and DQ during HLA typing, the behaviour of other antibodies and differences in dermatoglyphic examinations. Moreover there is a high ratio of women in the first two groups (61%) and conversely of men in groups 3 and 4. In the discussion attention is drawn to the different course of diabetes in patients with thyroid autoimmunity.

Glycoprotein hormone alpha-subunit secretion in prolactinomas and in non-functioning adenomas: relation with the tumour size.

OBJECTIVE: Free glycoprotein hormone alpha-subunit plasma levels have been reported to be increased in glycoprotein hormone-secreting adenomas and in acromegaly, but rarely in prolactinomas and in only two cases of Cushing's disease. The prevalence of elevated plasma alpha-subunit levels in patients with non-functioning adenomas is still unclear. In addition, no previous work has described plasma alpha-subunit levels in a comprehensive series of adenomas characterized by in-vivo secretion and/or immunocytochemistry. PATIENTS: Thirty-seven patients with definite prolactinomas and 48 with non-functioning tumours characterized by immunocytochemistry were studied, from a series of 145 consecutive patients including 33 acromegalics, 18 patients with glycoprotein hormone-secreting adenomas and 9 with Cushing's disease. MEASUREMENTS: Plasma free alpha-subunit was measured by radioimmunoassay in all patients and in a large sample of normal subjects to establish normal ranges according to sex, age and menstrual status. Tumour volume index was the product in cm3 of length, width and height of the adenoma as assessed by computerized tomography or magnetic resonance imaging. RESULTS: Twelve of the 37 (32%) patients with prolactinomas had increased plasma alpha-subunit levels; their tumours were significantly larger with significantly higher plasma PRL levels than those of patients without increased plasma alpha-subunit levels (P < 0.02). All prolactinomas above 50 cm3 were associated with alpha-subunit secretion, whereas only 6 of 29 smaller tumours were similarly associated. Twelve of the 48 'non-functioning' adenomas actually secreted alpha-subunit in vivo: 8 gonadotrophin-secreting, 2 'pure' alpha-secreting, one with negative immunocytochemistry and one necrotic adenoma. Their volumes were significantly higher than those of adenomas without increased plasma alpha-subunit levels (P < 0.04). Plasma alpha-subunit levels were increased in the 6 patients with TSH-secreting adenomas, 8 of 12 with FSH-secreting adenomas, 11 of 33 acromegalics and none of those with Cushing's disease. CONCLUSION: Plasma free alpha-subunit levels were increased in 49 of 145 patients (34%). For prolactinomas and 'non-functioning' adenomas, alpha-subunit hypersecretion was seen more often with larger tumours. Half of the cases with increased free alpha-subunit in this series were patients harbouring an adenoma which did not stain for an intact glycoprotein hormone.

[Hypocalcemic states]. / Hypokalcemické stavy.

The authors review contemporary knowledge of acute and chronic hypocalcaemia. They mention in more detail the most typical symptom of acute hypocalcaemia, tetany, and emphasize some chronic symptoms of chronic hypocalcaemia. Diagnostic difficulties may arise in particular in epileptic states, hypocalcaemic organic psychosyndrome and cataract. Diagnosis of their hypocalcaemic cause is important from the therapeutic and preventive aspect. The authors mention also states which may cause hypocalcaemia and finally they give an account of therapeutic possibilities in acute and chronic hypocalcaemia. Data from the literature are supplemented by the authors' data on the prevalence, pathogenesis and treatment of hypocalcaemia.

[The pituitary glycoprotein hormones, alpha subunit]. / Podjednotka alfa hypofyzárních glykoproteinových hormonu.

Pituitary glycoprotein hormones FSH (follicle-stimulating hormone), LH (luteinizing hormone) and thyrotropic hormone, TSH (thyroid-stimulating hormone) are formed by two subunits: alpha which is essentially the same for all three hormones, and beta which is responsible for their biochemical specificity. The alpha subunit is from the quantitative aspect a very important secretion of the pituitary. Part of the alpha subunit produced in the pituitary is not used for the synthesis of hypophyseal glycoprotein hormones and is secreted in a pulsed way synchronously with the pulsed LH secretion into the peripheral blood stream. Levels of the free alpha subunit in the peripheral blood depend on a number of factors in particular age, sex and in women on the stage of the menstrual cycle. The physiological roles of the free alpha subunit are only partially known. It is assumed that the most important part is the participation in the modulation of the effect of hypophyseal glycoprotein hormones at the level of their peripheral tissues. During the last few years it was revealed, surprisingly, that the level of the free alpha subunit in plasma may be used as a tumour marker as this parameter rises during some pathological conditions, in particular in adenomas of the pituitary.

Studies on the immunomodulatory effects of vitamin D.

The effect of vitamin D on T lymphocytes was investigated using the test of active E-rosettes formation. It was found that: 1. A single oral administration of 600,000 IU of vitamin D2 causes a significant increase in the formation of active E-rosettes. The peak of the increase was found 24 hours after the administration of vitamin D. The formation of E-rosettes the seventh day of the study was comparable with the pre-administration value; 2. Sera with higher concentration of 1,25-dihydroxyvitamin D[1,25(OH)2D] cause a significant increase in the formation of active E-rosettes; 3. Vitamin D is capable of reverting significantly the effect of a serum factor which suppresses the active E-rosettes formation. The authors observed a significant decrease in the effect of trypsin on the lymphocytes after oral administration of a single oral dose of 600,000 IU of vitamin D2. The trypsin-treated lymphocytes regained their lost capacity to bind sheep red blood cells (SRBC) when incubated with AB serum at 37 degrees C for 3 hours. The recovery of E-rosettes-forming capacity of trypsinised lymphocytes considerably increased when the cells were incubated with serum containing higher concentration of 1,25(OH)2D of 600,000 IU of vitamin D2.

[Life style risk factors in the etiopathogenesis of osteoporosis and possibilities of prevention]. / Civilizacní rizikové faktory v etiopatogenezi osteoporózy a moznosti prevence.

The prevalence of osteoporosis and its complications, in particular fractures of the femur, are rising and at present special attention is devoted to osteoporosis from the scientific, health and socio-economic aspect. The authors deal with factors of civilization which are involved in the aetiopathogenesis of osteoporosis and its complications and which can be influenced by preventive provisions. These factors which are part of the modern lifestyle comprise physical load, nutritional influences, the influence of toxic substances and drugs. As to nutritional factors the authors pay attention to an adequate calcium intake. They deal in detail also with aluminium intoxications. Attention is also drawn to the possible pathogenetic importance of stress and the authors contemplate on the inclusion of osteoporosis among diseases of civilization.