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A Pavlik

Publications and source records attributed to A Pavlik.

15 recordsLinked to original sources
PubMed2006

Increased brain uptake and brain to blood efflux transport of 14C-GABA in spontaneously hypertensive rats.

The brain uptake and brain to blood efflux transport of (14)C-GABA were studied in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats using 20 min bilateral in situ brain perfusion in rats anesthetized using urethane. The volume of distribution (Vd) of (14)C-GABA into cerebrospinal fluid (CSF) and brain regions (cortex, diencephalon, cerebellum, and brain stem) was significantly greater in SHR than in the corresponding regions in WKY rats (p<0.05). The estimated Vd value of (14)C-GABA in CSF of SHR was 3.4 fold greater than that in WKY. Also compared to WKY, the Vd of (14)C-GABA into cerebellum and cortex of SHR was 15.3 fold and 19.4 fold greater, respectively. Although the study of blood-brain barrier (BBB) integrity using (3)H-mannitol revealed increased paracellular permeability at the brain capillaries of SHR when compared to WKY rats, this was found to be only partially responsible for the increased (14)C-GABA uptake. The study of brain to blood efflux transport of (14)C-GABA (after loading of brain with (14)C-GABA by vascular perfusion) revealed that the half-time of elimination was significantly shorter in SHR (5.35+/-0.66 min) than in WKY rats (14.83+/-1.94 min), (p<0.001). HPLC analysis revealed that GABA concentrations in brain extracts and CSF of SHR were similar to those in WKY rats (p>0.05). The faster efflux in SHR might be, at least partially, responsible to compensate for increased uptake of this neurotransmitter and to preserve the protective function of BBB towards GABA. The protective function of the BCSFB towards GABA appears to be also preserved, since systemic infusion of GABA within a wide range of administered doses (0.004-5.00 mg/kg) produced an increase in GABA CSF concentration from around 0.5 microM to only 11 microM, and the obtained pattern of CSF GABA concentrations under these conditions did not differ between SHR and WKY rats, as revealed by HPLC.

Animals↗
PubMed2004

Neutron capture cross section measurement of 151Sm at the CERN neutron time of flight facility (n_TOF).

The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross section is of importance for characterizing neutron capture nucleosynthesis in asymptotic giant branch stars. At a thermal energy of kT=30 keV the Maxwellian averaged cross section of this unstable isotope (t(1/2)=93 yr) was determined to be 3100+/-160 mb, significantly larger than theoretical predictions.

Journal Article↗
PubMed2001

Surgical treatment of chronic acromioclavicular joint dislocation by modified Weaver-Dunn procedure.

We present our technique for surgically treating Tossy III acromioclavicular joint dislocation, discuss the indications for various procedures, and evaluate our postoperative results. We operated on 17 patients suffering from chronic acromioclavicular instability after such dislocation using a modified Weaver-Dunn procedure, in which there is no lateral clavicular end resection, the coracoacromial ligament graft is sutured to the inferior part of the clavicle by transosseal sutures, and a Bosworth coracoclavicular screw is used to protect the graft postoperatively for 8 weeks. After a mean of 37 months we evaluated shoulder function by the Constant score and the subjective and radiological results. Mean Constant score was 91.9% (74-100%); it was 80-90% in 5 patients and above 90% in 11. One patient had screw loosing after the operation and suffered partial loss of reduction and discomfort during shoulder loading. All patients but one returned to work, and all but one have returned to their preoperative activity at the same level. Subjectively, there were 11 excellent and 6 good results. Compared to the contralateral uninjured side, radiography showed anatomical reposition in the vertical plane in 9 cases, slight loss of reduction in 6 (difference in the distance between the inferior border of the acromion and the clavicle is 2-4 mm), and partial loss of reduction in 2 (4-8 mm). We recommend the modified Weaver-Dunn procedure for surgical treatment of chronic, Tossy grade III acromioclavicular joint dislocations as it provides good functional and subjective results. Our modification is indicated mainly for young patients because posttraumatic arthrosis occurs more frequently in elderly patients, making clavicular end resection necessary.

Acromioclavicular Joint↗
PubMed1998

Surgical treatment of pectoralis major rupture in athletes.

Complete rupture of the pectoralis major muscle, first described by Patissier in 1822, is a rare sports injury. Less than 100 cases have been reported in the literature since 1822. In this study, we describe our surgical technique and summarize our results and experience of the surgical treatment of pectoralis major rupture. Seven athletes (4 wrestlers, 2 handball players, 1 body-builder) were surgically treated in our department from 1981 to 1996. During the follow-up examination, five patients had excellent and two had good results, and six athletes could return to sports activity at their preoperative level. Among our patients we emphasize that of a wrestler, who had suffered an acute rupture, and 3 months after the surgery he won an Olympic gold medal. According to the literature and our experience, we suggest that only surgical repair of the acute pectoralis major rupture will result in both complete recovery and restoration of the full strength of the muscle, essential for active athletes.

Adult↗
PubMed1998

Changes in the expression of protease-activated receptor 1 and protease nexin-1 mRNA during rat nervous system development and after nerve lesion.

HDs racI Thrombin causes profound metabolic and morphological changes in cultured neural cells via activation of the thrombin receptor, also called protease-activated receptor 1 (PAR1). PAR1 mRNA is present in the rat brain, but the role of this receptor in the nervous system remains elusive. The expression of PAR1 and the potent thrombin inhibitor protease nexin-1 (PN-1) was investigated in the developing rat brain and spinal cord and after peripheral nerve lesion. As seen by in situ hybridization, the PAR1 mRNA signal in the late embryonic and early postnatal nervous system was widespread, but generally of low intensity whereas in the adult it was more pronounced and confined to particular neuronal cells. These include the mesencephalic dopaminergic neurons, several thalamic and brainstem nuclei, the mitral cells in the olfactory bulb and the Purkinje cells in the cerebellum. In the spinal cord, PAR1 mRNA was abundant in motoneurons and a particularly high expression was detected in the preganglionic neurons of the autonomic nervous system. High PAR1 mRNA expression was also found in the dorsal root ganglia. Interestingly, strong immunoreactivity for the protease inhibitor PN-1 was present in spinal motoneuron cell bodies, although its transcript was undetectable there. In response to sciatic nerve transection, the signal intensity of PAR1 mRNA as seen by Northern analysis increased in the proximal and the distal part of the lesioned nerve and in the denervated muscle, whereas the PN-1 mRNA signal strongly increased only in the distal part of the nerve but remained unchanged in the proximal part and in the muscle. After facial nerve transection, PAR1 mRNA expression substantially decreased in facial motoneurons. No PAR1 transcript was detected in reactive astrocytes. Similar to PAR1, PN-1 mRNA which was expressed in interneurons within the facial nucleus was also decreased following facial nerve transection.

Amyloid beta-Protein Precursor↗
PubMed1996

Sports ability after Bankart procedure in professional athletes.

Recurrent anterior shoulder instability and the restoration of sports ability after surgery are common problems, especially among professional athletes. The purpose of this study was to evaluate the rate, level and time of returning to sports activity activity after Bankart procedure in anterior shoulder instability in high level athletes. From 1992-1994 61 patients suffering from recurrent anterior shoulder instability were operated on open Bankart procedure, 44 out of 61 were professional athletes. There were 7 handball, 7 basketball, 6 football, 2 waterpolo and 1 baseball player and 4 wrestlers, 2 weight-lifters, 2 boxers, 3 bicyclists, 2 motorists, 2 swimmers, 2 sailors, 2 kayakers and 2 skiers. The mean duration of instability was 19.1 months (3-72) before operation. 29 patients had posttraumatic recurrent anterior dislocation and 15 patients had posttraumatic anterior subluxations. The average number of redislocations was 4.4, ranging from 2 to 11. At the follow-up examination the patients were tested clinically for instability using the special score created by Walch and Duplay and the Constant functional score. We measured the strength of the rotator cuff by Kintrex isokinetic device from the 10th postoperative week. 35 out of 44 professional athletes could be followed-up. The average follow-up period was 14.2 months, from 6 to 31. 88% of the patients were able to return to sports participation, 66% on the previous level and 22% on a lower level. 12% of the patients finished their professional sports career. The mean rehabilitation period was 5.8 months, the average period of full restoration of sports ability was 9.3 months. Similar results were documented with the Constant score and the Walch-Duplay test (88% excellent or good, 12% fair). The main reason for the inability to continue sports activity was some pain during extreme abduction and external rotation of the arm and recurrent sensations of subluxation (3 cases). Based on the results of the follow-up examinations an early diagnosis is paramount followed by timely surgical intervention to restore anatomical integrity in proven cases of shoulder instability in professional athletes. The open Bankart procedure is preferred giving excellent functional results and providing good chances for the athletes to return to their previous sports level.

Adolescent↗
PubMed1994

Glia-derived nexin/protease nexin-1 is expressed by a subset of neurons in the rat brain.

Glia-derived nexin/protease nexin-1 (GDN/PN-1) is a serine protease inhibitor that is secreted by glial cells and fibroblasts in culture. In the adult mammalian nervous system it has been shown to be expressed in the olfactory system and by some glial cells in response to neuronal injury. In situ hybridization and immunocytochemical studies were performed to identify the structures expressing GDN/PN-1 in the developing and adult rat brain. In contrast to a transient widespread expression during pre- and postnatal development, some brain structures constitutively express GDN/PN-1. These include the olfactory nerve layer of the olfactory bulb, basal forebrain, striatum, pyramidal neurons of layer V in the cortex, thalamic nuclei, pars compacta of the substantia nigra, inferior and superior colliculi, and deep cerebellar nuclei. All of these parts, excluding the olfactory nerve layer, are characterized by a high neuronal cell density. Neurons in these regions were immunoreactive for GDN/PN-1. Furthermore GDN/PN-1 expression in cell lines showed that the active protein was synthesized and secreted from B104 but not from NB2a neuroblastoma cells. Although GDN/PN-1 has only been reported to be synthesized by glia, the results presented here demonstrate that in addition, a subset of neurons express this protease inhibitor.

Amyloid beta-Protein Precursor↗
PubMed1977

Brain catecholamine metabolism and avoidance conditioning in rats.

Male albino rats were trained in a shuttle-box by presentation of 50 trials and were grouped according to the performance level. The disappearance of labelled catecholamine pool was studied after intraventricular injection of tritiated noradrenaline in the neocortex, brain stem, hypothalamus and hippocampus. Rats with a high performance level showed a greater disappearance rate of the labelled catecholamine pool than low or medium performers. In another experimental series the animals were grouped on the basis of their performance level which was tested 2 days before the intraventricular injection of the tracer. There was no significant difference in disappearance rates between the good and poor performances. It is assumed that integration of the goal-directed motor pattern is mediated through catecholaminergic (noradrenergic) neuronal mechanisms.

Animals↗
PubMedDate not supplied

[The effect of methylazoxymethanol on neuronal differentiation in the murine cerebellum].

The effect of methylazoxymethanol (MAM), an antimitotic drug, on granule and Purkinje cells of the rat cerebellum was studied. MAM was injected subcutaneously into ICR mice on day 5 after birth. The number of nucleoli and DNA content in nuclei of cerebellar neurons were determined 2 and 12 days after the injection. The number of nucleoli served as a criterion of maturity of neurons. On day 2 after MAM administration the proportion of Purkinje cells containing a smaller number of nucleoli increased suggesting a direct effect of MAM on maturation of Purkinje neurons. On day 12 no difference in the number of nucleoli was found between experimental and control animals but the number of granule cells containing multiple nucleoli increased significantly. The latter suggests that the studied cell population was supplemented with less mature cells. As a result, development of Purkinje and granule cells is desynchronized and that appears to determine the secondary effect of MAM on Purkinje cell differentiation.

Aging↗