Biomedical subjects

I Porsová-Dutoit

Publications and source records attributed to I Porsová-Dutoit.

9 recordsLinked to original sources

PubMed2006

[Male hormonal contraception].

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.

Contraceptive Agents, Male↗

PubMed2000

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.

Animals↗

PubMed1998

[The Internet and medicine. I. Historical development, current organizational structure, E-mail, the Web and discussion forums].

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.

Computer Communication Networks↗

PubMed1998

[The Internet and medicine. II. Present status and perspectives in the use of the Internet in Medicine].

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.

Humans↗

PubMed1996

[Thyroglobulin and microsome autoantibodies and their clinical significance in adult type I diabetics].

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.

Adult↗

PubMed1993

[The pituitary glycoprotein hormones, alpha subunit].

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.

Adolescent↗

PubMed1993

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.

Adjuvants, Immunologic↗

PubMed1993

[Hypocalcemic states].

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.

Acute Disease↗

PubMed1992

[Life style risk factors in the etiopathogenesis of osteoporosis and possibilities of prevention].

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.

Calcium, Dietary↗