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Biomedical subjects

P Haninec

Publications and source records attributed to P Haninec.

At least 19 recordsLinked to original sources
PubMed2006

The relevance of the corticographic median nerve somatosensory evoked potentials (SEPs) phase reversal in the surgical treatment of brain tumors in central cortex.

Tumors of the central brain cortex change the original anatomy of this important area and so an intraoperative localization of the perirolandic structures is crucial in decision concerning the way and the extent of tumor resection. The phase reversal of median nerve SEPs is an essential tool for neurosurgical procedures in and around the perirolandic gyri. This study examines the relevance of the method in a group of 62 patients having surgery of tumors in and around the central region. A success rate in obtaining the SEP phase reversal was 94%. In all groups of patients the complete resection of tumor was achieved in 58% , subtotal resection in 19% and partial or biopsy only in 23%. The long term impairment of neurological status was observed in 6% of patients. Compared to the recently published studies our results are acceptable both in completeness of tumor resection and relatively low ratio of impaired postoperative neurological deficit despite the fact, that in the majority of patients the phase reversal mapping was the only method guiding the surgical procedure. Our study supports the crucial role of the central cortex mapping using the SEP phase reversal method in the surgery for the tumors of the primary sensorimotor cortex.

Adult↗
PubMed2005

The effect of subarachnoid sodium nitroprusside on the prevention of vasospasm in subarachnoid haemorrhage.

OBJECTIVE: The aim of this study was to evaluate the effect of preventive and therapeutic use of subarachnoid sodium nitroprusside (SNP) administration in patients with non-traumatic subarachnoid haemorrhage (SAH). METHODS: All consecutive adult patients admitted in the period 2000-2003 with SAH, Hunt-Hess grade I-IV, indicated for neurosurgical intervention, were enrolled in the study. In the postoperative period they were treated with mechanical ventilation and triple H protocol with nimodipine. Subarachnoid preventive SNP was administred in initial dose of 1 mg by catheter inserted into basal cisterns during the neurosurgical procedure. The timing of following dosage was directed by the changes of respiratory parameters of brain tissue in the region of interest by multiparameter sensor (Codman Neurotrend) and findings of blood flow velocity on the level of circle of Willis were measured by transcranial doppler ultrasonography (TCD). RESULTS: 17 patients were enrolled to study. All patients survived. No brain infarction developed. The increase blood flow velocity was found in three patients. CONCLUSION: Preventive subarachnoid use of SNP in combination with multimodal monitoring might be a possible preventive strategy. Its efficacy has to be proved on a greater group of patients in the future. The therapeutical use of SNP requires an increase in application rate.

Adult↗
PubMed2004

Reinnervation of the rat musculocutaneous nerve stump after its direct reconnection with the C5 spinal cord segment by the nerve graft following avulsion of the ventral spinal roots: a comparison of intrathecal administration of brain-derived neurotrophic factor and Cerebrolysin.

Experimental model based on the C5 ventral root avulsion was used to evaluate the efficacy of brain-derived neurotrophic factor (BDNF) and Cerebrolysin treatment on motor neuron maintenance and survival resulted in the functional reinnervation of the nerve stump. In contrast to vehicle, BDNF treatment reduced the loss and atrophy of motor neurons and enhanced the regrowth axon sprouts into the distal stump of musculocutaneous nerve. However, the axon diameter of the myelinated fibers was smaller than those of control rats. The morphometric results were related to a low score in behavioral test similar to vehicle-treated rats. Cerebrolysin treatment greatly protected the motor neurons against cell death. Moreover, morphometric features of myelinated axons were better than those of rats treated with vehicle or BDNF. The mean score of grooming test suggested better results of the functional motor reinnervation than after BDNF administration. The majority of rescued motor neurons regenerating their axons through nerve graft in both BDNF- and Cerebrolysin-treated rats expressed choline acetyltransferase immunostaining. The results demonstrate that BDNF has more modest effects in preventing the death of motor neurons and functional recovery of injured motor nerve after root avulsion than Cerebrolysin.

Amino Acids↗
PubMed2004

Morphological evidence of collateral sprouting of intact afferent and motor axons of the rat ulnar nerve demonstrated by one type of tracer molecule.

In our experimental paradigm we sutured the distal stump of a transected musculocutaneous nerve to an intact ulnar nerve of the rat in an end-to-side fashion. We demonstrated the formation of collateral sprouts from intact afferent and motor axons by application of one type of molecule conjugated by two different fluorophores (Fluoro-Ruby and Fluoro-Emerald). Fluoro-Ruby and Fluoro-Emerald were applied distal to end-to-side suture into fresh cut ends of the ulnar and musculocutaneous nerves, respectively. Formation of collateral sprouts was evidenced by findings of mixed (a yellow to orange color) fluorescence labeling of spinal motoneurons and dorsal root ganglia neurons. Colocalization of two different tracers retrogradely transported to the neurons was verified by the individual green and red fluorescence profiles analyzed by means of the computer-assisted image-analyzing system. Our results unequivocally demonstrate that a nerve stump attached to an intact nerve can induce collateral sprouting of both afferent and motor axons.

Afferent Pathways↗
PubMed2001

Laminin molecules in freeze-treated nerve segments are associated with migrating Schwann cells that display the corresponding alpha6beta1 integrin receptor.

Isolated acellular nerve segments protected from migration of Schwann cells and the acellular nerve segments joined with the distal nerve stumps were prepared by a repeated freeze-thaw procedure in the rat sciatic nerves. The presence of laminin-1 and -2, as well as alpha6 and beta1 integrin chains, was detected by indirect immunohistochemistry in the sections through acellular nerve segments at 7 and 14 days after cryotreatment. The position of basal laminae and Schwann cells was identified by immunostaining for collagen IV and S-100 protein, respectively. The isolated cryo-treated segment without living Schwann cells (S-100-) did not display immunoreactivity for laminins and integrin chains, while the basal lamina position was verified through the whole segment by immunostaining for collagen IV. The absence of immunostaining for laminin-1 and -2 in cryo-treated nerve segment was verified by Western blot analysis. A crucial diminution of laminin-1 and -2 in the cryo-treated nerve segment of 10-mm length did not abolish the growth and maturation of axons. The greater part of nerve segment connected with the nerve stump displayed no immunohistochemical staining for S-100, corresponding with absence of Schwann cells. The border region of the nerve segment contained Schwann cells (S-100+) migrating from the near-freeze undamaged part of the distal nerve stump. In addition to immunostaining for S-100 protein, the migrating Schwann cells displayed immunostaining for laminins (-1, and -2) and integrin chains (alpha6 and beta1). The results indicate that the presence of laminin molecules in the acellular nerve segments prepared by the repeated freeze-thaw procedure is related with the migrating Schwann cells. The immunostaining for laminins and integrin chains, which constitute one of integrin receptor, suggests an autocrine and/or paracrine utilization of laminin molecules in the promotion of Schwann cell migration.

Animals↗
PubMed2001

Morphometric analysis of early regeneration of motor axons through motor and cutaneous nerve grafts.

Peripheral nerve damage is a frequent consequence of trauma, tumor surgery or diseases. Clinical results of functional reinnervation after the application of cutaneous grafts are still unsatisfactory. Differences in the extracellular matrix are considered to be one of the factors responsible for poor results of motor axon reinnervation through the cutaneous graft. To verify these differences, we compared morphological features of the motor axons regenerating through the graft prepared from the saphenous nerve and the motor branch of the femoral nerve. Eighteen female adult rats (Wistar) were used in experiments. The saphenous nerve, the femoral nerve, and its main motor branch were exposed under deep anesthesia with ketamine and xylazine. The nerve graft (10 mm) prepared from the saphenous nerve was applied between the stumps of the transected motor branch of the femoral nerve in the 6 rats. In the next 6 rats, the nerve graft (10 mm) harvested from the motor branch of the femoral nerve was inserted between stumps of the transected motor branch of the femoral nerve on the contralateral side. All rats were perfused with Zamboni's fixative solution 14 days after grafting. The samples of grafts and the intact motor branch (n = 6) were dissected and embedded in Durcupan ACM. Semithin sections stained with Toluidine Blue were used for morphometric analysis of myelinated axons by means of computer-assisted image analysis system. Ultrathin sections counterstained with uranyl acetate were viewed and photographed in an electron microscope. The number of myelinated motor axons showing early regeneration under conditions of the cutaneous and motor nerve grafts was similar. The diameter of axons and thickness of their myelin sheaths were significantly smaller when the axons regenerated into the saphenous nerve in contrast to the motor graft. Morphometric analysis of early regeneration of myelinated motor axons suggests that the cutaneous and motor branches of the femoral nerve provide different conditions not for the growth but for the maturation of motor axons.

Animals↗
PubMed2001

Reconstruction of elbow flexion, wrist and finger extension by transposition of pedicled latissimus dorsi muscle and flexor carpi ulnaris muscle.

The technique of restoring extension of the hand and fingers is described in an inveterate injury of the brachial plexus. The insertion of m. flexor carpi ulnaris was transferred with an intact nervous and vascular supply to different tendons of the m. extensor digitorum closely above the retinaculum extensorum. The muscle strength was 4--using Janda's muscle test. Dorsal flexion of the hand was possible from the basic position, with extension of the fingers to their full extent. Anatomical investigation revealed that the mean length of the caput humerale m. flexor carpi ulnaris is 26.5 cm, the number of final nerve branches 2-3, the mean length of the nerves varies between 1.3-2.3 cm, the vascular supply is in 90% directly from the ulnar artery. In 10% of dissections the vascular supply is from the anterior ulnar recurrent artery. The length of the vascular bundle is 3.2 cm. In 10% of upper extremities examined an additional vascular bundle was present which was 2 cm distal from the main hilus, also from the a. ulnaris. The pattern of the neurovascular supply is no impediment for the transposition of the insertion tendon into the regio antebrachii posterior. The transfer of the insertion tendon of the m. flexor carpi ulnaris in inveterate injuries of the brachial plexus is a useful alternative for the reconstruction of nerves to restore the extension of the hand and fingers.

Elbow Joint↗
PubMed2000

Acellular nerve graft re-seeded by Schwann cells migrating from the nerve stump can stimulate spinal motoneurons for functional reinnervation of the rat muscle.

The acellular nerve graft was utilised to restore a functional reinnervation of the biceps brachii muscle from the motoneuron pool of the cervical spinal cord. The musculocutaneous nerve stump was sutured to an acellular nerve graft, the opposite end of which was inserted into the cervical spinal cord cranial to the avulsed C5 ventral root. The acellular nerve graft was repopulated by Schwann cells heavily immunostained for NGFr within 90 days. The Schwann cells migrating from the nerve stump reached the spinal cord grey matter, where they stimulated the motoneurons to send axonal sprouts. The functional reinnervation of the biceps brachii muscle was assessed by means of the behavioural (grooming) test and EMG, the presence of myelinated and unmyelinated axons was demonstrated by light and electron microscopy. The axonal reconnection of the musculocutaneous nerve stump was verified by horseradish peroxidase retrograde labelling of the spinal motoneurons. Moreover, the motoneurons on the operated side of the C5 spinal segment displayed increased immunostaining for GAP-43 in comparison to the contralateral side, whereas the pattern of AChE histochemical reaction was similar on both the operated and contralateral side, of the C5 segment 150 days after acellular graft implantation. The regenerated axons bridged a 4-cm long originally acellular nerve graft to reach and reinnervate the biceps brachii muscle. The reinnervation of the neuromuscular junctions was morphologically determined by immunofluorescence for neurofilaments. The number of myelinated axons in the acellular nerve graft was significantly higher than those growing over the cellular graft, but their diameter was smaller. The results of experiments presented here demonstrate functional recovery of the biceps muscle reinnervation through the acellular nerve graft repopulated by migrating Schwann cells. The process of reinnervation by acellular nerve graft is however delayed and worse in comparison with the cellular graft.

Animals↗
PubMed1999

An alternative preparation of the acellular muscle graft for reconstruction of the injured nerve--morphological and morphometric analysis.

The application of cutaneous nerve grafts is accompanied by some disadvantages, including insufficient graft material for the reconstruction of a large mixed nerve. Recently, evacuated muscle autografts have been suggested as possible alternatives to cutaneous nerve grafts. In the present paper we have demonstrated a possible preparation of the evacuated muscle graft using an infiltration of Marcaine. The reinnervation of the distal stump of the rat median nerve was evaluated by morphological and morphometric analysis after application of the muscle acellular grafts prepared by three methods: an ordinary freeze-thawed muscle graft, a Marcaine evacuated muscle graft and a Marcaine treated graft with subsequent freezing and thawing. A comparison of the numbers and diameters of the myelinated axons in the distal nerve stumps revealed very similar conditions for axon regrowth and maturation in Marcaine evacuated and freeze-thawed muscle grafts. The best results with myelinated axon numbers and spectrum of their calibres were obtained when the Marcaine treated graft was repeatedly frozen and thawed. The pre-treatment of the muscle graft by Marcaine prevents it from shrinking and fragmenting, the main disadvantage during freeze-thawing of fresh muscle. The present results demonstrate that infiltration of striated muscles with a myotoxic compound, e.g. Marcaine, with subsequent freezing-thawing is the method of choice for the preparation of an acellular muscle graft used in peripheral nerve reconnection in the experimental model.

Animals↗
PubMed1999

Reconstruction of elbow flexion by transposition of pedicled long head of triceps brachii muscle.

A new technique of restored flexion in the elbow joint in an inveterate injury of the brachial plexus is described. The insertion of the long head of the triceps brachii muscle was transferred with an intact nervous and vascular supply to the anterior brachial region and sutured above the radial tuberosity with the insertion tendon of the biceps brachii muscle. The muscle strength three months after surgery according to the muscle test was 4-. Flexion in the elbow joint was possible up to 85 degrees. Extension in the elbow joint was preserved, the muscle strength was 3. Anatomical investigation revealed that the mean length of the nerve of the long head of the triceps was 5.5 cm, the number of terminal branches was 3-4, 70% of the vascular supply was from the brachial artery, the length of the vascular bundle was 3.6 cm. In 33% there was an additional neurovascular hilus which was 2-3 cm distally from the main hilus. The investigation confirms that the neurovascular pedicle of the long head of the triceps brachii muscle is sufficiently mobile and damage by traction during transposition of the insertion tendon is therefore not likely. Transfer of the long head of the triceps brachii muscle in inveterate injuries of the brachial plexus is a suitable alternative for reconstruction of nerves or transfer of other muscles to restore flexion in the elbow joint.

Arm↗
PubMed1999

Immunohistochemical localization of laminin-1 in the acellular nerve grafts is associated with migrating Schwann cells which display corresponding integrin receptors.

The presence of laminin-1, collagen-IV, alpha6 and beta1 integrin chains was detected by indirect immunohistochemistry using biotin/streptavidin/HRP or gold-conjugated secondary antibody at the light and electron microscope level, respectively. Cryo-treated segment of the peripheral stump without living Schwann cells (S-100-) did not display immunoreactivity for laminin-1 and integrin's chains, while the migrating Schwann cells in the marginal regions were immunostained for the antigens. Isolated acellular nerve segments protected from migration of Schwann cells (S-100-) exhibited laminin-1-, beta1-, and alpha6- integrin chains immunoreactivities. Position of the basal lamina was verified by collagen-IV+ immunoreactivity. Results indicate that presence of the laminin in the peripheral nerve is related with living Schwann cells.

Animals↗
PubMed1998

Reconstruction of paralyzed biceps brachii muscle by transposition of pedicled latissimus dorsi muscle: report of two cases.

The biceps brachii muscle was reconstructed in two patients with inveterate injuries of the brachial plexus. The latissimus dorsi muscle was transferred on the thoracodorsal neurovascular bundle into the regio brachii anterior and sutured to the long head of the m. biceps brachii. The distal part of the latissimus dorsi muscle was sutured above the tuberositas radii along with the insertion tendon of the biceps brachii muscle. Both patients achieved very satisfactory restoration of flexion in the elbow joint 12 and 16 months after surgery.

Adult↗
PubMed1996

[Surgical treatment of injuries of the recurrent laryngeal nerve].

The authors give an account of the results of suture and decompression of the n. laryngeus recurrence in 15 patients with a mean follow up period of 17,6 months. A total of 12 nerves were sutured, one of them by means of an autograft from the n. suralis. A total of 11 nerves were decompressed. One patients after suture of the nerve and contralateral decompression did not attend a check-up examination. Of 11 sutured and checked nerves the results were very good in ten instances when a remarkable improvement of the voice was recorded as well as of the adduction movement and phonation closure of the vocal cords. In one instance the suture of the nerve failed. After decompression of the nerve in seven instances recovery of the function of the affected vocal cord occurred. After decompression of another two nerves the adduction movement of the vocal cord was restored, the voice became normal and phonation closure occurred. In one instance the nerve decompression failed. EMG examinations were made in three instances after suture of the nerve and in one instance after decompression of the nerve. The EMG examination correlated with the clinical finding. With regard to these results it is possible to recommend after injuries of the n. laryngeus recurrence its revision. The results of suture of the nerve or its decompression within five days after injury are very satisfactory in the group of patients treated by the authors.

Adolescent↗
PubMed1992

Origin of cells in contact with the growth cones of embryonal peripheral nerves and histochemical detection of nonspecific cholinesterase activity in quail-chick and chick-quail chimeras.

The types of cells contacted by growth cones were examined in chick-quail and vice versa chimeras. Simultaneously, the presence of nonspecific cholinesterase (nChE) was monitored in developing peripheral nerves of these embryos. In all the chimeras studied, the growth cones were in contact with both Schwann cell progenitors and mesenchymal cells of the limb bud. This observation implies that the growth cones may obtained guidance cues directly from the mesenchymal cells of the limb bud. Schwann cell progenitors as well as mesenchymal cells in contact with growth cones were capable to produce nChE molecules. The reaction product indicating nChE activity was localized on the outer surface of the plasma membrane of both types of cells in contact with growth cones. However, mesenchymal cells forming the "primitive perineurium" were devoid of the reaction product on their plasma membrane. We conclude that with exception of classic adhesive molecules the process of axonal guidance can be mediated by nChE molecules.

Animals↗
PubMed1990

Localization of dipeptidylpeptidase IV and alkaline phosphatase in developing spinal cord meninges and peripheral nerve coverings of the rat.

Localization of dipeptidylpeptidase IV was studied in the spinal cord meninges and peripheral nerve coverings of fetal and postnatal rats. In the same sections, the localization of alkaline phosphatase was monitored. In the prenatal period, dipeptidylpeptidase (DPP) IV activity in the differentiating meninges appeared at the time of cerebrospinal fluid spaces formation (on day 16 in the cervical region and on day 18 in the lumbar region). In adult animals DPP IV was found in cells of those meningeal lamellae which delineated the cerebrospinal fluid spaces (the outer, intermediate and inner lamellae), in the perineurium, in Schwann cells and in some fibroblasts of the bulk of dura mater. It is suggested that DPP IV plays a role in the metabolism of neuropeptides by their interaction with cerebrospinal fluid. Alkaline phosphatase activity was detectable earlier than DPP IV activity. Positivity was first observed in some cells of the meninx primitiva and, later on, in the ectomeninx and also in the differentiating endomeninx where it disappeared postnatally. The developing ectomeninx exhibited activities of both enzymes. Alkaline phosphatase occupied its external layers, while DPP IV was localized in its inner layers. This enzymatic heterogeneity of the ectomeningeal layers suggests that the ectomeninx gives rise not only to dura mater (which in adult animals exhibits alkaline phosphatase activity) but also to the outer arachnoid layer (positive for DPP IV in adult rats).

Aging↗
PubMed1990

Non-specific cholinesterase activity of the developing peripheral nerves and its possible function in cells in intimate contact with growing axons of chick embryo.

The results presented here demonstrate non-specific cholinesterase (nChE) activity in the developing peripheral nerves of chick embryos at stages 25-26 according to Hamburger and Hamilton (1951, J. Morphol. 88, 49-92). Under the light microscope the use of simultaneous staining for nChE activity and silver proteinate impregnation revealed the axons to be surrounded by cells exhibiting nChE activity in the main nerve trunks and in the growing tips of nerves. Nerve branches arising from the main nerve trunks contained cells with positive reaction for nChE activity, too. Electron-dense particles of the reaction product indicating nChE activity were found in the rough endoplasmic reticulum and in the perinuclear envelope of cells in close contact with growing nerve fibers and their growth cones. The same distribution of nChE activity was found in cells which were located near to nerve fasciculi but without direct contact with axons. Surprisingly, the cells in close contact with axons and their growth cones exhibited the end product of nChE activity in the outer part of their plasma membrane. The cells enveloping axons within the nerve trunks were apparently Schwann cells, while those around the growth cones at nerve tips could be identified as Schwann cells and/or mesenchymal cells of the hindlimb. The nChE reaction product was also detected in the axolemma of nerve fibers and their growth cones. The distribution of nChE activity in the developing peripheral nerves of chick embryos suggests that these molecules may influence the process of axonal elongation and locomotion. Several possible mechanisms of nChE action on growing axons can be presumed: (i) intracellular Ca2+ level regulation; (ii) providing an adhesive substrate; and (iii) butyrate production affecting the cell metabolism and the distribution of neurotubules and neurofilaments. It is also assumed that nChE molecules are involved in the interactions of nerve fibers with Schwann cells and/or mesenchymal cells as well as in interneuronal interactions.

Animals↗