The West Bohemia earthquake swarm foci are approximated by a circular seismic source model, which radius is assumed to depend only on magnitude of the event. We consider two different models of average slip (i) a constant slip and (ii) a slip exponentially scaled to the magnitude of the event. Based on these assumptions, we stacked the contributions of individual events into representative final fault slip. We processed in such a way four significant swarms recorded during the last three decades in 1986, 1997, 2000 and 2008. Constant slip model indicates final slip was composed of 2 or 3 principal asperities located on one or two different planes. On the contrary, scaled slip model indicates that one big asperity prevails. It is not possible yet to select the preferred slip model. Analysis of the temporal activity of all swarms generally shows three principal phases: starting phase, main phase and fading phase; the upwards trend of activity spreading was observed (slip animation is presented in www supplement http://www.ig.cas.cz/kolar/StopPhase/Asperity). The maximal possible cumulative slip value may have reached the order of meters., Petr Kolář, Bohuslav Růžek, Alena Boušková and Josef Horálek., and Obsahuje bibliografii
Receptory pro vitamin D jsou přítomny téměř ve všech tkáních těla. Vitamin D nefunguje jen jako regulátor metabolizmu vápníku a fosforu, ale i jako látka modulující funkci imunitního systému, regulující proliferaci buněk. Genetická, epidemiologická a experimentální data nasvědčují pro možnou roli deficitu vitaminu D při vzniku některých chorob, především autoimunitních onemocnění a nádorů. Přínos léčebného podávání vitaminu D se doposud nepodařilo prokázat. Není důvod nehradit deficit vitaminu D. Substituce by měla začít úhradou chybějícího množství vitaminu D (řádově i několik set tisíc jednotek) s trvalým podávání doporučené substituční dávky 800–1 000 jednotek vitaminu D za den., Receptors for vitamin D are present almost in all body tissues. Vitamin D does not only act as a regulator of calcium and phosphorus metabolism, but also a substance which modulates the immunity system function, regulates cell proliferation. Genetic, epidemiological and experimental data indicate a possible role of vitamin D deficiency in the development of some diseases, mainly of autoimmune diseases and tumours. The benefit of curative intake of vitamin D has so far not been proven. There is no reason why the deficiency of vitamin D should not be covered. The substitution should start with the replenishment of the lacking amount of vitamin D (which may even be several hundred thousand units) and involve ongoing intake of the recommended substitution dose of 800–1 000 vitamin D units per day., and Vladimír Kojecký
In this review we summarize recent opinions on the possible role of vitamin D in the risk of thyroid diseases development. It may be concluded from the available data that vitamin D deficiency, particularly levels below 12.5 ng/ml should be considered as an additional, but important risk factor for development of thyroid autoimmunity, both chronic autoimmune thyroiditis and Graves´ disease. A higher risk of Graves´ disease development is also associated with several polymorphisms in the gene encoding for vitamin D binding protein and for the specific receptor of active form of vitamin D - 1,25-(OH)2D3 in the respective target cells. Important for development of thyroid cancer appeared polymorphisms of genes encoding for vitamin D receptors and of genes encoding for the participating hydroxylating enzymes in thyroid tissue, leading to a diminished local 1,25-(OH)2D3 formation capacity with following alteration of antiproliferatory, antiapoptotic and prodifferentiating efficacy of the latter. Whether supplementation with high doses of vitamin D or its analogues possesses preventive or therapeutic effect is an object of intensive studies., K. Vondra, L. Stárka, R. Hampl., and Obsahuje bibliografii
Reduced levels of vitamin or its metabolites have been reported in various psychiatric disorders. Insufficient levels of vitamin D in depressive patients have been confirmed by many authors, but there have been conflicting results in subjects with anxiety disorders. In the present cross-sectional study, levels of calcidiol were determined in groups of depressive men and women and in men and women with anxiety disorders and compared with age matched controls. Significantly lower levels of calcidiol were found in men and women with depression as well as in age matched patients with anxiety disorders., M. Bičíková, M. Dušková, J. Vítků, B. Kalvachová, D. Řípová, P. Mohr, L. Stárka., and Obsahuje bibliografii
Insufficient levels of vitamin D have been demonstrated by many
authors as a risk factor for autistic patients, however, the
causality has not been reliably elucidated. In the present study,
levels of calcidiol were determined in group of autistic children
and compared with age matched healthy children as controls.
Suboptimal levels of calcidiol in more than 60 % of both autistic
patients as well as of control group were found. No significant
differences in vitamin D between autistic children and healthy
controls were observed.
The relationship between vitamin D receptor (VDR) intragenic polymorphisms FokI, BsmI, ApaI and TaqI and bone mineral density (BMD) or biochemical markers of bone remodeling were investigated in 114 Czech postmenopausal women, on the average 62.5±8.9 years of age. Restriction fragment length polymorphisms in the VDR gene were assessed by PCR amplification and digestion with restriction enzymes FokI, BsmI, ApaI, and TaqI recognizing polymorphic sites in the VDR locus. Bone mineral density was measured at the lumbar spine and at the hip by dual-energy X-ray absorptiometry (DEXA, g/cm2). After adjusting for age and the body mass index (BMI), subjects with the ff genotype had 9.4 % lower BMD at the hip than those with the Ff genotype (p=0.0459, Tukey´s test). FF individuals had an intermediate BMD at the hip. A similar pattern of lower lumbar spine BMD was also found in ff individuals, but it did not reach statistical significance. There was no relationship between BsmI, ApaI and TaqI VDR polymorphisms and BMD at any skeletal site. Subjects with Aa (ApaI) genotypes had higher levels of propeptide of type I collagen (PICP) than homozygous AA (p=0.0459, Tukey´s test). In FokI, BsmI and TaqI restriction sites the biochemical markers of bone remodeling did not differ by genotype. In addition, no significant difference was observed in VDR genotypic distribution between osteoporotic women and non-osteoporotic controls in the study group. To conclude, the FokI genotype of the vitamin D receptor gene is related to bone mass at the hip in Czech postmenopausal women, whereas the importance of remaining VDR genotypes was not evident., K. Zajíčková, I. Žofková, R. Bahbouh, A. Křepelová., and Obsahuje bibliografii
In women with chronic autoimmune thyroiditis and vitamin D deficiency we have found reference levels of relevant metabolichormonal parameters except for parathormone and total calcium. Three months supplementation with vitamin D (4300 IU/day, cholekalciferol) did not lead to significant changes of investigated hormonal parameters, while the levels of parathormone and calcium reached normal levels. However, a correlation analysis revealed marked changes in mutual relations. First, an inverse correlation of vitamin D with parathormone, insulin secretion (C peptide, insulin) and its efficiency (HOMA IR) disappeared. Relationships of vitamin D to hepatic insulin resistance (insulin/C peptide), to DHEA (both negative), and to DHEAS/DHEA ratio (positive) were newly found. Second, a positive correlation of CRP with insulin secretion remained, while its relation to insulin efficiency (HOMA IR, insulin/ C peptide) was newly observed. Analogical positive correlations appeared also among anti TPO and insulinemia, insulin/C peptide, HOMA IR, and anti Tg to C peptide. A relationship of the CRP with anti TPO became significant (+). Third, out of glucose metabolism parameters only insulin/C peptide and glycemia did not correlate with vitamin D during its deficiency, while after supplementation insulin/ C peptide alone correlated positively with both DHEAS and DHEA, and negatively with vitamin D., K. Vondra, R. Bílek, P. Matucha, M. Salátová, M. Vosátková, L. Stárka, R. Hampl., and Obsahuje bibliografii
We examined the upregulation of ET-1/ETBR/eNOS signaling in renoprotective effect of vitamin D in kidney fibrosis model in mice using unilateral ureteral obstruction (UUO). One group was treated with intraperitoneal injection of 0.125 mg/kg of Calcitriol (UUO+VD). Vascular remodeling was quantified based on lumen area and lumen/wall area ratio (LWAR) of intrarenal arteries using Sirius Red staining. ET-1, ETBR, eNOS, CD31 and VEGF mRNA expressions were quantified using qRT-PCR. Focusing on endothelin-1 (ET-1) signaling in endothelial cells (EC), siRNA of ET-1 was performed in human umbilical vein endothelial cells (HUVEC) for reducing ET-1 expression. Then HUVECs were treated with and without 100 nM Calcitriol treatment in hypoxic and normoxic conditions to elucidate ET-1/eNOS signaling. Our in vivo study revealed vascular remodeling and renal ischemia attenuation after Calcitriol treatment. Vascular remodeling was attenuated in the UUO+VD group as shown by increasing lumen areas and LWAR in intrarenal arteries. These findings were associated with significant higher CD31 and VEGF mRNA expression compared to the UUO group. Vitamin D treatment also increased ET-1, ETBR and eNOS mRNA expressions. Our in vitro study demonstrated Calcitriol induced ET-1 and eNOS mRNA expressions upregulation in HUVEC under normoxic and hypoxic condition. Meanwhile, siRNA for ET-1 inhibited the upregulation of eNOS mRNA expression after Calcitriol treatment. Vitamin D ameliorates kidney fibrosis through attenuating vascular remodeling and ischemia with upregulating ET-1/ETBR and eNOS expression., N. Arfian, M. H. H. Kusuma, N. Anggorowati, D. B. Nugroho, A. Jeffilano, Y. Suzuki, K. Ikeda, N. Emoto., and Seznam literatury
Vitamin D had been for a long time investigated for its effects on bone metabolism. Recently has been observed that the incidence of some neurodevelopmental disorders (including autism) increases hand in hand with vitamin D deficiency. Indeed, vitamin D was reported to modulate the biosynthesis of neurotransmitters and neurotrophic factors; moreover, its receptor was found in the central nervous system. Vitamin D deficiency was therefore assessed as a risk factor for autism, however the biological mechanism has not yet been revealed. In our review we focused on potential connections among vitamin D, steroids and autism. Potential mechanisms of vitamin D action are also discussed., L. Máčová, M. Bičíková, D. Ostatníková, M. Hill, L. Stárka., and Obsahuje bibliografii
Polyhydroxylated derivatives of 6-keto,7-dehydrocholesterol (ecdysteroids) are common constituents of various plants.
In 1965, they were accidentally discovered in the search for the insect moulting hormone. These biologically important natural
compounds are neither insect hormones nor inducers of insect ecdysis. Due to their strong anabolic, vitamin D-like effects in insects, domestic animals and humans, I propose the use of the arbitrary term vitamin D1
. The present paper describes the effects
of vitamin D1
on the growth and regeneration of excised epidermal cells of the tobacco hornworm, Manduca sexta (Sphingidae).
The periods of programmed cell death and cell proliferation (histolysis and histogenesis, respectively) exactly coincide in insects
with endogenous peaks of increased concentration of vitamin D1
. Epidermal cells communicate with each other, creating a mutually integrated tissue, connected by mechanical, chemical, electrical, ionic or other so far incompletely known factors. After natural
cell death, or after the artifi cial removal of some epidermal cells, the neighbouring cells that lose communication integrity, begin
to divide mitotically to replace the disconnected part. Cell divisions are arrested as soon as the integrity of the living tissue is
established. During insect ontogeny, the application of juvenile hormone causes regenerating epidermal cells to repeat the previous morphogenetic programme (i.e., development of patches of larval tissue on the body of a pupa, or metathetely). Conversely,
the application of vitamin D1
(20-hydroxyecdysone) caused the regenerating cells to prematurely execute a future morphogenetic
programme (i.e., development of patches of pupal tissue on the body of a larva, or prothetely). Among the key features of insect
regeneration, is the arrest of cell divisions when tissues resume living cell-to-cell integrity. This prevents the formation of aberrant groups of cells, or tumours. It is well established that the main physiological systems of insects (e.g., circulatory, respiratory,
neuro-endocrine) are structurally and functionally similar to corresponding systems in humans. Thus the basic principles of cell
regeneration and the role of vitamin D1
in insects may also be valid for humans. The common vitamins D2
(ergocalciferol) or D3
(cholecalciferol), are exclusively lipid soluble secosterols, which require activation by UV irradiation and hydroxylation in the liver.
By contrast, the neglected vitamin D1
is a natural derivative of polyhydroxylated 7-dehydrocholesterol of predominantly plant origin, which is both partly a water and partly a lipid soluble vitamin. It neither requires UV irradiation, nor hydroxylation due to 6 or
7 already built-in hydroxylic groups. Like other vitamins, it enters insect or human bodies in plant food or is produced by intestinal
symbionts. Vitamin D1
causes strong anabolic, vitamin D-like effects in domestic animals and in humans. I am convinced that
avitaminosis associated with a defi ciency of vitamin D1 in human blood may be responsible for certain hitherto incurable human
diseases, especially those related to impaired nerve functions and somatic growth, aberrant cell regeneration or formation of
malignant tumours.