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Biomedical subjects

P Haninec

Publications and source records attributed to P Haninec.

27 records · Page 2Linked to original sources
PubMed1989

Specular and scanning electron microscopy in diffuse silicone keratopathy.

In a 50-year-old man, penetrating keratoplasty was carried out to treat a diffuse silicone keratopathy that developed 2 years after a pars plana vitrectomy combined with an intravitreal silicone injection for a complicated retinal detachment in the only aphakic eye. At 2 weeks after the intravitreal silicone injection, specular microscopy revealed a mild pleomorphism in the corneal endothelium and an endothelial cell loss of 26%. After 5 months, a small silicone drop floated in the anterior chamber and the first signs of diffuse keratopathy were observed. At the same time, specular microscopy revealed severe damage to the endothelial cells and a cell loss of 69%. After the keratoplasty, scanning electron microscopy of the corneal button showed a filamentous structure of the posterior surface of the cornea, with fibroblast-like cells; the endothelial cells were absent.

Anterior Chamber↗
PubMed1988

Fine structure histochemical study of the distribution of dipeptidylpeptidase IV (DPP IV) in the meningeal lamellae of the rat.

DPP IV was localized in the meningeal lamellae of the spinal cord sheaths of the rat by light and electron microscopy. A membrane-bound reaction product of DPP IV was found in the internal, intermediate and external meningeal lamellae which delineated the CSF-filled meningeal spaces. The cells of the marginal glia displayed heterogeneous localization of the reaction product for DPP IV. DPP IV distribution in the spinal cord sheaths suggests its possible participation in the interactions of the meningeal cells with the neuropeptides in cerebrospinal fluid.

Animals↗
PubMed1988

Study of the origin of connective tissue sheaths of peripheral nerves in the limb of avian embryos.

Quail-chick and chick-quail chimeras were constructed by grafting, isotopically, the limb bud of quail embryos into a chick of the same developmental stage and vice versa, prior to the entry of nerve fibres into the limb. After 5-14 days reincubation of the embryos, the components of the connective tissue sheaths of the peripheral nerves were observed by using Feulgen-Rossenbeck staining and light microscopy, in order to distinguish quail cells and chick cells. In all the chimeras studied, the connective tissue sheaths of peripheral nerves (the epineurium, perineurium, perineural septa and endoneural fibroblasts) were formed from the mesenchyme of the limb bud, while Schwann cells were of host origin. Also the outer and inner capsule of muscle spindles originated from the limb bud mesenchyme. These experiments suggest that the connective tissue sheaths of peripheral nerves (at least in the limb region of avian embryos) are not of neural crest origin, but are formed from limb bud mesenchyme.

Animals↗
PubMed1988

Tyrosinase protein is expressed also in some neural crest derived cells which are not melanocytes.

Some neural crest cells give rise to pigment cells in early ontogenesis. We tested here whether tyrosinase--a key enzyme in melanogenesis--was present in some pigment neural crest derivatives in adult hamsters. Interestingly enough, inactive tyrosinase protein was detected, using indirect immunofluorescence, in the satellite cells of spinal ganglia and Schwann cells of sciatic and facial nerves in normal adult animals. The results of cell blotting from spinal ganglia were similar to the fluorescence findings. Thus, our results seem to support the hypothesis that Schwann cells, satellite cells of spinal ganglia, and melanocytes may be more intimately related developmentally than other neural-crest-derived cells. Moreover, since we detected tyrosinase protein in cells which normally do not produce melanosomes, it could be deduced that, during the melanocyte's differentiation from its cell precursor, the expression of tyrosinase protein might precede the point when melanosomes begin to differentiate from known cytoplasmic structures.

Animals↗
PubMed1988

Occurrence of three supernumerary muscles in adult human hand supporting recent developmental concept of muscle layers in the autopodium.

The authors report on the simultaneous occurrence of short supernumerary muscles on the palmar and dorsal sides of an adult human hand. The supernumerary muscle on the palmar side of the hand took its origin from the tendon of the m. flexor digitorum superficialis in the distal third of the forearm, sharing its insertion with that of the m. lumbricalis primus, and taking its innervation from the n. medianus. With regard to its origin, the muscle may be a supernumerary belly of the m. flexor digitorum superficalis which failed to make its way to the forearm during development. With regard to its insertion, though, it can just as well represent a detached part of the m. lumbricalis primus whose tendon became attached to the m. flexor digitorum superficialis at the time of simultaneous development of those muscles of the hand. By their origin, insertion, innervation and position, the muscles on the dorsal side of the hand were identified, in part, as mm. interossei dorsales accessorii in the 2nd and 3rd intermetacarpal spaces which are constantly found in man as a developmental feature to become rudimentary in some cases later on, in part, as an anomalous m. extensor digitorum brevis of the 2nd and 3rd fingers.

Hand↗
PubMed1986

Undulating course of nerve fibres and bands of Fontana in peripheral nerves of the rat.

The undulating course of nerve fibres and the optical effect of that course, i.e. the bands of Fontana, were studied in the peripheral nerves of the adult rat using light microscopy. The arrangement of collagen fibres in the endoneurium of these nerves was evaluated using transmission and scanning electron microscopy. No nerve fibres undulation was noted on the intracranial sections of the cranial nerves or on the spinal roots. In their endoneurium a few, irregularly arranged collagen fibrils were found. In contrast, the nerve fibres undulation and Fontana's bands were a constant feature in the peripheral course of the nerve trunks. They were discernible in vivo and on excised unfixed as well as fixed nerves. The nerve fibres follow a sine-curve course of variable frequency and amplitude. Exposed in vivo, the nerve fibres retained their wave-like course even after removal of the epineurium and perineurium. The endoneurium of these nerves contained numerous undulating longitudinally oriented bundles of collagen fibrils. These findings suggest that the undulating course of the nerve fibres in peripheral nerves is conditional upon the quantity and arrangement of their endoneurial collagen fibrils. When the nerve was stretched in the course of movement, the undulation became straightened out until it disappeared. Conversely, nerve shortening enhanced the undulation. Thus the wave-like alignment of the nerve fibres represents a physiological reserve length for nerve stretching.

Animals↗
PubMed1981

Functional properties of muscle autografts substituted for the rat levator ani muscle.

The present report deals with the functional properties (contraction parameters and neuromuscular transmission) of muscle grafts and transposed muscles substituted for the levator ani muscle in the rat. The experiments were divided into four main groups. Group I - the levator ani [LA] was excised and replaced in its own bed. Group II - the extensor digitorum longus, a fast muscle (with or without predenervation), and Group III - the soleus, a slow twitch muscle, were substituted for the LA. In group IV, the gracilis anterior muscle was either freely grafted in place of the LA or transposed a) with intact innervation, b) with its vascular supply intact or c) with preserved neuro-vascular supply. The optimum results of twitch and tetanic tension, and the amplitude of stimulation EMG responses was found in the case of LA resutured into its own bed and in the case transposition of the gracilis anterior muscle had been performed with its neuro-vascular supply intact in place of the LA. On the basis of these functional findings and morphological and anatomical observations (Grim et al. 1982), a surgical procedure is suggested for patients with anal incontinence (Grim et al. 1981, Dittertová-Vlasáková et al. 1982).

Anal Canal↗