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M Doskocil

Publications and source records attributed to M Doskocil.

At least 19 recordsLinked to original sources
PubMed1996

Caput mandibulae accessorium.

The presented anomaly consists of a doubled mandibular condylus in a boy aged 5.5 years. We report this case because of its rare localisation, shape, size and microscopic pattern. It represents a doubled articular process arising from the mandibular processus coronoideus. From the morphologic view the finding is very exceptional. We failed to find any similar case in the literature available. The findings of doubled articular processes (condylus bifidus) previously quoted are of different origin. In this case it was obviously disorder in the differentiation of the mandible within the period when the mandibular ramus basis was formed by the secondary cartilage.

Cartilage↗
PubMed1995

[Development and biomechanics of the talocrural joint].

We have studied the development of talocrural joint in fetuses, newborns and children. The results of the microscopical, anatomical and biomechanical studies are as follows: 1. The distal extremities of tibia and fibula are joint not only by the distal part of the tibiofibular syndesmosis, but also by an articulation (articulation tibiofibularis distalis). Its articular cavity communicates with the cavity of the talocrural joint and is visible on its arthrographic pictures. This articulation enables the mutual shift and rotation between distal extremities of tibia and fibula-during the plantar flexion fibula turns and shifts round tibia anteriorly, by the dorsal flexion posteriorly. 2. We recommend to preserve the possibility of mutual movements of tibia and fibula in all cases of the surgical treatment of talocrural injuries. 3. Analysis of prostheses of talocrural joint showed why they cannot be functionally successful. They do not respect the physiological movements, the small articulations of tarsus are overloaded. Pain, arthrosis and functional collapse results in these small articulations, because the prostheses change the axis of movements and the biomechanics at all. 4. We have defined conditions for a successful talocrural prosthesis. 5. Study of the topography of the attachment of the Achilles tendon showed, that it develops medially from the axis of the extremity and therefore rotates in the fetus the foot in the equinovarus position. The tendon shifts till the axis during the second half of fetal life. When this shift is temporarily stopped or slown down, the syndrome of pes equinovarus congenitus develops. We recommend the modification of the surgical treatment of pes equinovarus congenitus: transposition of the Achilles tendon in the axial position.

Ankle Joint↗
PubMed1993

Contribution to the study of the development and ossification of human sternum.

We have studied the development of sternum in man. Complete microscopic series of sections through thorax of human embryos and fetuses from the second and third months of gestation served as the research material. Preparations were stained by Alcian blue and Mayer's haematoxyline, counterstained by eosine. We also had a set of macroscopic preparations of sterna and adjacent parts of ribs from fetuses of the fifth and sixth months of gestation. These specimens were stained by Alcian blue and by Alizarine and subsequently cleared by glycerine method. We have found that sternum develops by a fusion of sternal bars. Sternal bars develop from anterior bent parts of ribs, lying one over another like tiles. The newly formed sternum has different proportions in comparison to its definitive state. In all the cases its manubrium is wider and bigger, its xiphoid process is longer, in almost all the cases doubled or at least bifurcated. The sternocostal junctions are provided with interzones with the exception of the first rib. Its primordium continues into sternum without any border. Clavicle is connected with sternal anlage without any visible border and this interzone quickly develops as the primordia of the sternoclavicular articulation and the disc. In the medial part, there is a cartilaginous model which ossifies very early--as the first bone of the body. In young embryos from the end of the second month of gestation the clavicle and sternum show very different structures. Ossification of the sternum begins in the fifth month by developing a large number of very small centers of ossification which are not yet detectable by X-ray or CT.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1993

[Ontogenic development of the temporomandibular cavity in man].

We have studied the size and configuration of the human temporomandibular joint pit in Man. We have treated a set of 158 skulls representing all age categories--ranging from the end of prenatal period till the oldest age. We have measured the maximal transverse dimension of the pit and sorted out categories according to the state of denture (DENT 1-7). We have also measured the maximal longitudinal dimension (in reality both measured dimensions are oriented slightly obliquely, perpendicularly to each other). The last measured parameter has been the depth of the pit. All three parameters served for the pit width-length index computation. We have discovered the following changes during the development: at the beginning of the monitored developmental stage the pit is very flat and round-shaped. With the denture development (starting with the milk-denture already) the pit changes into an oval-shaped, deep structure. With the 2nd denture development continues in all trends, although in a slower way. At teeth losses in the old age category the pit becomes shallower again but not as flat as in childhood.

Anthropometry↗
PubMed1993

On vertebral body growth.

We have studied development of vertebral bodies with special regard to the area of contact of the vertebral body with the intervertebral disc. We have investigated complete serial sections of fetuses of the 2nd to 3rd month of intrauterine life, microscopic preparations from children, adolescents and young adults. The results of our studies and deductions from our findings are as follows: 1. Cartilaginous plates on contact surfaces of vertebral bodies with intervertebral discs are genetically parts of vertebral bodies, not of the discs. 2. During ontogenesis and growth period of life typical growth (epiphyseal) cartilages with all layers described on growth cartilages of long bones are formed on the surface of these cartilaginous plates facing the vertebral bodies. 3. From the point of view of its growth, the vertebral body should be considered to be a long bone. 4. Unlike other long bones of the skeleton, vertebral body epiphyses never ossify, and after the end of the growth period of life they are reduced into thin plates of hyaline cartilage which are situated between vertebral body and intervertebral disc. 5. We assume nucleus pulposus is not a persistent residuum of notochord. 6. According to our findings the link of sacral vertebral segments is from the very beginning of development typical synchondrosis with bipolar physes without formation of primordium of intervertebral disc.

Adolescent↗
PubMed1991

Observations on the biological activity of epitestosterone.

Epitestosterone, a 17 alpha-epimer of testosterone is a normal constituent of body fluids in many species including man. It has long been believed that it is devoid of any biological significance. However, it is now demonstrated that in in vivo experiments on castrated male mice it counteracts the action of testosterone on androgen-dependent organs. In vitro experiments show that on the overall antiandrogenicity of epitestosterone participate true antiandrogenic action due to the binding to androgen receptors, strong 5 alpha-reductase inhibiting activity as well as a weak antigonadotropic activity. Epitestosterone is devoid of any embryotoxicity as checked by chick embryo-toxicity screening test.

5-alpha Reductase Inhibitors↗
PubMed1991

Meniscoids in the small articulations in extremities of man.

Synovial folds in the primordia of the small articulations of the human hand and foot are described. The folds are constant in the stages of development during which the articular cavities are formed and they very often persists in adults. They are structurally very similar to the meniscoids described by Kos and Wolf in intervertebral articulations.

Foot↗
PubMed1989

[Developmental aspects of regeneration of the spinal cord (observations on chick embryos)].

The reaction of the embryonic spinal cord to mechanical transversal myelotomy has some general features: 1. It is above all a glial reaction and repair by a glial scar which is the more subtle, the younger the damaged embryonic tissue. 2. The younger the spinal cord, the more powerfully it responds by proliferative reactions. 3. We never observed restoration of the original spinal architecture. The older the embryo, the more marked the defects of the grey and white matter. 4. During transversal myelotomy in older embryos after damage of already develop spinal pathways irreversible disconnection of the spinal cord from higher compartments of the CNS occurs and this is manifested by a marked reduction of the spontaneous activity of the spinal generator of embryonic motorics with all sequelae for its further morphological and functional development.

Animals↗
PubMed1989

Mechanism of the reduction of Meckel's cartilage in man.

The mechanism of reduction of the anterior end of Meckel's cartilage was studied in human embryos, with the following findings: 1. Meckel's cartilage is surrounded, from the outside and from below, by newly formed mandibular bone over the extent of the insertion of the musculus mylohyoideus. 2. Blood vessels from the newly formed bone penetrate Meckel's cartilage and break it down in the same way as in enchondral ossification of cartilaginous models of other bones. 3. The anlagen of the musculus mylohyoideus and musculus genioglossus are at first inserted on Meckel's cartilage; further muscle fibres, formed on the under surface of the two muscles, are inserted on the newly formed bone of the rudimentary mandible. Parallel to this process, the fibres on the upper surface of the muscles, which were originally inserted on Meckel's cartilage, disappear. The two processes combined lead to transposition of the insertions of the two muscles from Meckel's cartilage to the mandible. 4. In the area of the resorbed Meckel's cartilage, a minimum number of bone trabeculae are formed at the time of its resorption. The space left by Meckel's cartilage is taken over chiefly by the primitive medullary cavity of the rudimentary mandible, medially to the canal for the nerve and blood vessels.

Cartilage↗
PubMed1988

Steroid-protein adduct in the lens of chicken embryo following application of prednisolone esters.

Protein--prednisolone adducts were detected by semiquantitative radioimmunoassay in both water- and urea soluble fractions of homogenates from lenses of chicken embryos, given systemically single doses (100 microliters each) of four prednisolone esters. The findings were correlated with macroscopic changes of lens transparency. The highest concentrations of protein-associated immunoreactive material were found after prednisolone sulphate application, associated with the most apparent loss of transparency.

Animals↗
PubMed1987

Microscopic-anatomical changes in the chick embryo after administration of 9-(RS)-(2,3-dihydroxypropyl) adenine.

Microscopic-anatomical changes were followed in embryos of white leghorn fowl 1-5 days after administration of 9-(RS)-(2,3-dihydroxypropyl) adenine on day 2 of incubation. The main changes involved the spinal cord, eyes, and extremities, manifesting gross structural abnormalities. Development of the limb buds appeared to be arrested at stages corresponding to the third day of incubation, with their apical ectodermal ridges frequently absent. A conspicuous feature of all the experimental embryos was a seriously damaged spinal cord. The disturbance of spinal cord development was reflected in defective formation of vertebral anlagen. Development of eye anlagen was arrested at the optic cup stage. The lens, however, developed normally. No causal relationship between the CNS abnormalities and limb damage was determined.

Abnormalities, Drug-Induced↗
PubMed1986

The role of corticosteroids in the homeostasis of the eye.

Three problems were studied on the human and rabbit eye: to what extent the mineralocorticoids contribute to the control of Na+ and K+ transport in the lens epithelium, how do the glucocorticoids influence the concentration of glucose in the aqueous humour and what is the effect of the pituitary-adrenal axis on the hemato-ocular barrier. Specific receptor-like proteins binding aldosterone were found in the lens epithelium. Na+ and K+ concentrations in the aqueous were influenced by both aldosterone and spironolactone administration. The aldosterone concentration in human cataracts was found to be higher in cases of cataracts complicated by arterial hypertension. In spite of some indication of anticataractogenous action of mineralocorticoids, aldosterone did not prevent the formation of cortisol-induced cataract in chick embryos. Glucose concentration in the aqueous was increased by glucocorticoid administration as well as by stimulation of their secretion by ACTH. Further, the contribution of the pituitary-adrenal axis to the breakdown of the hemato-ocular barrier was investigated by measuring the changes of the total protein content in the aqueous. ACTH1-24 caused a partial breakdown of the barrier, as well as ACTH4-10 or alpha-MSH. As the latter two peptides lack the stimulative effect on the corticoid secretion and glucocorticoids themselves fail to increase the protein content in the aqueous, the breakdown of the hemato-ocular barrier seems to be essential for ACTH-linked peptide fragments and is not mediated by corticoids.

Adrenal Cortex Hormones↗