Biomedical subjects

P Gál

Publications and source records attributed to P Gál.

At least 19 recordsLinked to original sources

PubMed2006

Early changes in the tensile strength and morphology of primary sutured skin wounds in rats.

The specific aim of this study was to measure the TS of rat skin wounds during the first week following surgical injury. Biomechanical and histological data were collected daily (days 1 to 7 following surgery) from separate groups of Sprague-Dawley rats (N = 12) each with two 3 cm long parallel skin incisions on the back. The wounds were immediately closed by four simple sutures. A control group (N = 15) was used to obtain TS measurements of unwounded skin. TS was measured by applying a ramp load until wound separation and estimated by dividing the yield strength by the wound area. The time course of biomechanical recovery followed a step-plateau pattern with the largest increase in TS observed one day after surgery (0 - 1.60 g/cm(2)). The plateau stage extended from day 1 to 5 (1.60 - 3.88 g/cm(2)). The final step (day 5-7) indicated a period of rapid rise in wound TS (3.88 - 11.57 g/cm(2)). Since even on day 7 the mean TS was only 4% of unwounded skin, the wound had to be protected from tensile loads. Histological analysis confirmed that the early changes in TS (day 1) correlated with the fibrin accumulation of the wound edges followed by a plateau stage caused by the tissue proliferation. The rapid increase in wound TS was characterized by cross-linking the incisions with collagen fibres with escalating organization. We conclude that from a biomechanical perspective, sutures can be removed during the "plateau phase", but the wound must be protected from tensile loads.

Animals↗

PubMed2006

[Treatment of congenital pseudarthrosis of tibia by vascularized fibular graft].

PURPOSE OF THE STUDY: The aim of the study was to evaluate the results in a group of patients with congenital pseudarthrosis of the tibia treated by transfer of a vascularized fibular graft from the contralateral extremity. MATERIAL: The group included three boys and two girls aged 2 to 8 years at the time of surgery. In two patients, the vascularized graft transfer was preceded by other operations. All patients but one had Crawford type IV pseudarthrosis. The signs of peripheral neurofibromatosis were found in four of the five patients. METHODS: The operation was carried out by two surgical teams, i. e., orthopedic and microsurgery (plastic surgery) specialists. Deep dissection of the pseudarthrosis was performed down to healthy, well vascularized tissue; a vascularized pedicle bone graft was harvested from the contralateral fibula. The graft was inserted and anchored intramedullarily in both tibial fragments, and stability was provided with a K-wire introduced through the calcaneus. Subsequently, the vascular pedicle of the fibular graft was joined to the surrounding vessels (anterior tibial artery and anterior tibial vein). The extremity was immobilized in plaster cast and later a KAFO brace was applied. RESULTS: Graft union partially failed in the proximal end of the graft due to bone resorption of both the graft and the proximal tibial fragment in two patients. This was successfully treated by additional spongioplasty. In all patients bony union was achieved at an average time of 9.8 months (range, 6 to 21 months). An increase by more than 100 % in the diameter of the transplanted fibula was recorded in four patients. The increase, which was of course related to follow-up time, was a clear proof of primary graft vascularization. DISCUSSION: The use of vascularized fibular graft harvested from the contralateral extremity showed high effectiveness in comparison with other methods. This was in agreement with the relevant literature reports. CONCLUSIONS: This method can be used regardless of patients' age and our experience showed that, even in small children, union can be achieved and can thus allow for early weight-bearing and prevention of crus atrophy.

Bone Transplantation↗

PubMed2006

[Different views on the association between cannabinoids and cancer].

Cannabinoids are the major active components of the most widely used illegal drug - marihuana. They have a long history of the medicinal use. However, they are still a controversial topic in oncological praxis. Cannabinoids play a role in different organs of human body and they are an integral part of the newly described endocannabinoid system, which regulates several body functions. The important function of endocannabinoids which is related to cancer, is the regulation of cell cycle and cell survival pathways. Presented review gives three different views on the association between cannabinoids and cancer. First, the treatment of adverse symptoms of oncological therapy - nausea and vomiting inhibition, appetite stimulation, pain relieving, mood modulation and muscle stiffness relieving. Second, in the late 1990s, three possible mechanisms of antitumour action were identified - apoptosis induction, direct cell cycle arrest and angiogenesis and metastasis inhibition. The phase I/II of clinical trials are carrying out in Spain. They study effects of local administration of tetrahydrokanabinol on the growth of glioblastoma multiforme. Third, the results of the newest study focused on the association between cannabinoids use and cancer risk showed no significant association between increased cancer incidence and cannabinoids use and it does not depend on the amount of used cannabis. It is important to establish the association between marihuana use and cancer risk regarding the consideration of advantages and risks of medicinal cannabinoids use and the impact on public health.

Animals↗

PubMed2006

[Results of the elective laparoscopic appendectomy in unexplained pains in the right hypogastrium].

AIM: The aim of this study is to assess results of surgical therapy in female patients with clinical diagnoses of unexplained pains in the right hypogastrium. STUDY GROUP: The study was conducted with a group of female patients, who were indicated for elective laparoscopic appendectomy. All girls underwent complete laboratory and clinical examinations prior to the procedure, and, later, histological findings and peroperative findings were added. The patient group was then re-examined retrospectively. All procedures were conducted at the Clinic of Paediatric Surgery, Orthopaedics and Traumatology in Brno. METHODOLOGY: A follow-up examination of clinical symptoms was the primary method in the study. After 3 years of the procedure, the girls were asked to fill in a questionnaire, including 5 questions with pre-defined answers. Complete records of 67 female patients were obtained during the period 1997-2000. RESULTS AND CONCLUSION: Over 80% of the enquired female patients experienced no further symptoms. The study confirmed positive effects of elective appendectomies in unexplained pains in the right hypogastrium.

Abdominal Pain↗

PubMed2006

[Data collection and the Czech Republic Trauma Registry].

INTRODUCTION: A trauma registry is an integral part of any thorough traumatological care conception. The essential task of such a data collection is to provide complex information on conditions, treatment, outcomes and trauma treatment costs, considering a region or other registered part of, usually, a state entity. MATERIAL, METHODOLOGY: Registration of individual trauma characteristics throughout the state territory is a prerequisite for creating a data set, providing information for making valid conclusions applicable for all ranges of human activity. The trauma registry outputs are essential for traffic institutions, police, commercial inspection, commercial and health insurance companies, hospitals, etc. With respect to traffic problematics, the trauma registry plays a significant role in pointing out the most risk places in the region, in assessing the traffic type and use of protective tools. Furthermore, it facilitates exact aiming of preventive and corrective measures. CURRENT CONDITION: Current legislation does not require reporting data to the trauma database, insufficient data are provided by UZIS only. Our Clinic of Paediatric Surgery, Orthopaedics and Traumatology iniciated a model version of the Czech Republic National Trauma Registry. Our activities were approved by and supported by the Society of Traumatologic Surgery. It is a question of time, when sufficient pressure is exerted and the trauma registry becomes an integral part of the traumatological care in the Czech Republic.

Accidents, Traffic↗

PubMed2006

[Remodelling ability of the distal radius in fracture healing in childhood].

INTRODUCTION: Distal forearm fractures are among the commonest skeletal injuries in childhood. The aim of this work is to analyze factors determining remodelling abilities of the distal radial metaphysis in dislocated fractures, considering a requirement for eventual non-operative repositioning. MATERIAL AND METHODOLOGY: The primary patient group included a group of patients treated in 2004 for distal radial metaphysis fractures, left to heal in a dislocated position. The angle of dislocation ranged from 8 to 30 degrees. All patients underwent a follow up x-ray examination 2, or more, years later and a clinical examination of the wrist joint range of motion. The extent of remodellation was studied, considering duration of the healing process, patient's age and the fracture line distance from the growth plate. RESULTS: The results show that in the majority of the patients included in the study, complete remodellation of the radius nearly to its anatomical position (86%) occurred. The results were significantly better in the patient group aged 0-12 years. Furthermore, significantly less residual dislocations were recorded within 20 mm from the growth plate. Restriction of the wrist joint range of motion resulting from residual dislocation was not recorded. CONCLUSION: Based on the results, conservative treatment of the condition, especially in cases of multiple injuries or of a polytrauma, is recommended. Also, in cases of deterioration of the positioning or of redislocation after repositioning, repositioning need not be repeated in patients below 12 year of age.

Adolescent↗

PubMed2005

[Effect of laser irradiation of diode laser on healing of surgical wounds in rats].

The aim of this work was to continue in previous study, which concerns biostimulation of skin wound healing evaluated after 24, 48, 120, 168 hours and so complete the chronological continuance of the process during the first seven days. Male, Sprague-Dawley rats (n=21) were used for the experiment. The rats were divided into 3 groups of 7 animals. In general anaesthesia (combination of xylazine, ketamine and tramadol) under aseptic condition two 3,5 cm long parallel skin incisions were performed on the left and right side of the rats spine and immediately sutured. The left wounds were daily stimulated with the diode laser (670 nm). The right wounds were not stimulated and served as control. The specimens of skin wounds were removed for histological evaluation 72, 96 and 144 hours after surgery. The biological specimens were stained with hematoxylin and eosin and histopathologically evaluated. In summary, in our histomorphological study of the influence of laser irradiation on primary wound healing evaluated after 72, 96 and 144 hours was concluded, that the healing of stimulated wounds was accelerated in comparison with controls. The histological evaluation showed earlier regress of inflammatory phase, faster finishing of reepithelization and acceleration in maturation phase. Presented experimental study completes the previous study and achieves the positive effect of biostimulation on all phases of skin wound healing in vivo.

Animals↗

PubMed2005

[Massive spongioplasty and external fixation in the posttraumatic pseudoarthrosis management--a case review].

The authors of this case review present three cases of posttraumatic pseudoarthroses as complications of open fractures of the forearm and the course of their treatment. External fixation with the Ilizar external fixation apparatus and bridging spongioplasty was applied in all patients. In the first presented case, the external fixation and spongioplasty was required after resection of the atrophic posttraumatic pseudoarthrosis. In the remaining two cases, furthermore, transposition of the distal fragment of the radius using distraction in order to correct its position against the distal part of the ulna, was required. The pseudoarthroses healed in all three subjects. The case review highlights the key significance of the external fixation method and the massive spongioplasty.

Adolescent↗

PubMed2004

[Percutaneous endoscopic gastrostomy in children].

AIM: The authors evaluate their experience with percutaneous endoscopic gastrostomy in children at the age of three months to 14 years. COHORT: Forty three patients treated with this method in the years 1995-2002. METHODS: The percutaneous endoscopic gastrostomy is applied in children under general anesthesia. In two patients only it proved to be necessary to convert to open or laparoscopic gastrostomy. RESULTS: Only minor complications were encountered. CONCLUSIONS: It became obvious that percutaneous endoscopic gastrostomy is a suitable method to provide long-term enteral nutrition in children of child age who may not be nourished sufficiently by natural ways.

Adolescent↗

PubMed2004

[Options for correction of post-traumatic length discrepancies in forearm bones in children (case reports)].

Correction of radius length after a premature complete or partial closure of the distal epiphyseal plate is important for both the correction of radial deviation of the hand and the restoration of normal function of the radiocarpal articulation. This study comprised four patients. Two children with complete closure of the epiphyseal plate of the distal radius underwent callotaxis. One patient was treated for atrophic pseudoarthrosis of the distal radial metaphysis by external fixation and subsequent spongioplasty. One patient with partial closure of the epiphyseal plate was treated by physeal distraction. In each patient an Ilizarov's external fixator was applied. The full correction of radius length was achieved in all cases. No complications were recorded with the exception of tissue irritation around Kirchner's wires, which occurred mainly on the volar side. In the therapy of injuries suffered during adolescent growth acceleration, it is necessary to perform a certain overdistraction of the radius. An alternative method includes epiphyseodesis of the distal ulna. Key words: post-traumatic closure of the epiphyseal plate, callotaxis, physeal distraction, chondrodiatasis.

Adolescent↗

PubMed2003

Inhibition of C1q-beta-amyloid binding protects hippocampal cells against complement mediated toxicity.

Activation of complement by beta-amyloid (A beta) contributes to the pathology of Alzheimer's disease (AD). Here, we show that C1-Inhibitor (C1-Inh) protects cultured rat hippocampal cells against beta-amyloid induced complement lysis indicating a classical pathway-mediated activation mechanism. We report on screening of compound libraries to identify compounds that inhibit C1q binding to beta-amyloid. Characterization of these compounds revealed that C1q possessed distinct binding sites for beta-amyloid and antibodies. One selected compound protected cultured hippocampal cells against complement-dependent beta-amyloid toxicity. These results provide evidence that complement has the potential to damage hippocampal cells, and C1q is a relevant target to suspend this deleterious mechanism in Alzheimer's disease.

Amyloid beta-Peptides↗

PubMed2003

[Injuries of the fingernail area in childhood].

The authors submit a summary of the most recent findings on the damage of the nail area of the fingers of the hand (nail matrix, surrounding soft tissues, skeleton excluding avulsion fractures and epiphyseolyses.). The reason is the fact that almost 50% of all finger injuries in children under 5 years include also damage of this complex. Although the incidence of this injury is relatively high there is no uniform therapeutic procedure and unfortunately very frequently therapeutic procedures do not lead to favourable results. This apparently trivial injury can however, in particular in relation to occupation, lead not only to cosmetic but also functional disorders and therefore it is necessary to pay adequate attention to it. The authors supplement data from the literature by their own experience with the treatment of this comprehensive injury. The objective of the work is therefore to summarize available therapeutic findings on the classification and diagnostic procedures of these apparently light injury from the layman's aspect and unfortunately also from the aspect of some professionals, these injuries being overlooked and underrated (Innis, 1995). Particular attention is however devoted to adequate treatment which must lead to restoration of the injured fingers to full function which subsequently will restore the comprehensive role of the whole hand.

Child↗

PubMed2002

[Pathology of the spleen in children--current possibilities of surgical treatment].

In the submitted paper the authors review the contemporary state of surgery of the spleen in child age. Surgical treatment is used most frequently in injuries of the spleen, in portal hypertension and in haematological diseases. In a group of patients during the last decade efforts to preserve the spleen are emphasized and experience is reported with the use of therapeutic procedures. The authors emphasize that splenectomy in children should be an exceptional operation.

Child↗

PubMed2002

[Serologic detection of hantavirus antibodies].

Within the framework of diagnosis of highly dangerous infections in the Army of the Czech Republic serological assessment of hantaviral antibodies was introduced. Because military units in the field can be in contact with sources of hantaviral infections, the authors investigated this population sample. In 1999-2000 a total of 542 healthy subjects were examined (age 20-40 years). Hantaviral antibodies were detected in 9. In three antibodies against the serotype Hantaan were found, in two antibodies against serotype Puumala and in four against serotype Seoul. The mean seropositivity was 1.66%. As compared with results which were obtained in the National Institute of Public Health in Prague in 1998 in a sample of the general population (430 subjects) where seropositivity of hantaviral antibodies was 0.93% the seropositivity in military units is higher. It is thus essential to make this laboratory diagnosis in the laboratories of the Army of the Czech Republic.

Adult↗

PubMed2002

[Treatment of redislocated fragments of long bones using plaster cast wedging].

The authors wish to remind of the advantages of an old conservative therapeutic method used in redislocated long bone fractures--cast wedging, Gipskeilung. This mode of treatment makes it possible to restore axial as well as planar dislocation and it is used in corrections of redislocated fractures of the leg and is applied during the last 3 years also in the treatment of fractures of the forearm in children. In 1997-2000 this procedure was used for treatment at the Clinic of Paediatric Surgery, Orthopaedics and Traumatology, 33 children aged 3-16 years, with a redislocated fracture of the leg, 21 children aged 3-16 years, mean age 9.8 years, and with a redislocated fracture of the forearm 12 children aged 5-15 years, mean age 10.2 years. In no instance this treatment failed or was associated with serious complications. According to experience with our group of patients a method is involved which in correct indications holds a justified place in treatment of fractures of the leg and forearm in traumatology of child an adolescent age.

Adolescent↗

PubMed2001

The role of the individual domains in the structure and function of the catalytic region of a modular serine protease, C1r.

The first enzymatic event in the classical pathway of complement activation is autoactivation of the C1r subcomponent of the C1 complex. Activated C1r then cleaves and activates zymogen C1s. C1r is a multidomain serine protease consisting of N-terminal alpha region interacting with other subcomponents and C-terminal gammaB region mediating proteolytic activity. The gammaB region consists of two complement control protein modules (CCP1, CCP2) and a serine protease domain (SP). To clarify the role of the individual domains in the structural and functional properties of the gammaB region we produced the CCP1-CCP2-SP (gammaB), the CCP2-SP, and the SP fragments in recombinant form in Escherichia coli. We successfully renatured the inclusion body proteins. After renaturation all three fragments were obtained in activated form and showed esterolytic activity on synthetic substrates similar to each other. To study the self-activation process in detail zymogen mutant forms of the three fragments were constructed and expressed. Our major statement is that the ability of autoactivation and C1s cleavage is an inherent property of the SP domain. We observed that the CCP2 module significantly increases proteolytic activity of the SP domain on natural substrate, C1s. Therefore, we propose that CCP2 module provides accessory binding sites. Differential scanning calorimetric measurements demonstrated that CCP2 domain greatly stabilizes the structure of SP domain. Deletion of CCP1 domain from the CCP1-CCP2-SP fragment results in the loss of the dimeric structure. Our experiments also provided evidence that dimerization of C1r is not a prerequisite for autoactivation.

Catalytic Domain↗

PubMed2001

Assembly and enzymatic properties of the catalytic domain of human complement protease C1r.

The catalytic properties of C1r, the protease that mediates activation of the C1 complex of complement, are mediated by its C-terminal region, comprising two complement control protein (CCP) modules followed by a serine protease (SP) domain. Baculovirus-mediated expression was used to produce fragments containing the SP domain and either 2 CCP modules (CCP1/2-SP) or only the second CCP module (CCP2-SP). In each case, the wild-type species and two mutants stabilized in the proenzyme form by mutations at the cleavage site (R446Q) or at the active site serine residue (S637A), were produced. Both wild-type fragments were recovered as two-chain, activated proteases, whereas all mutants retained a single-chain, proenzyme structure, providing the first experimental evidence that C1r activation is an autolytic process. As shown by sedimentation velocity analysis, all CCP1/2-SP fragments were dimers (5.5-5.6 S), and all CCP2-SP fragments were monomers (3.2-3.4 S). Thus, CCP1 is essential to the assembly of the dimer, but formation of a stable dimer is not a prerequisite for self-activation. Activation of the R446Q mutants could be achieved by extrinsic cleavage by thermolysin, which cleaved the CCP2-SP species more efficiently than the CCP1/2-SP species and yielded enzymes with C1s-cleaving activities similar to their active wild-type counterparts. C1r and its activated fragments all cleaved C1s, with relative efficiencies in the order C1r < CCP1/2-SP < CCP2-SP, indicating that CCP1 is not involved in C1s recognition.

Binding Sites↗

PubMed2001

Structure and function of complement activating enzyme complexes: C1 and MBL-MASPs.

The complement system is a major effector arm of the immune defense contributing to the destruction of invading pathogens. There are three possible routes of complement cascade activation: the classical, the alternative and the lectin pathways. The activation of the classical and lectin pathways is initiated by supramolecular complexes, which resemble each other. Each complex has a recognition subunit (C1q in the classical and mannose-binding lectin (MBL) in the lectin pathway), which associates with serine protease zymogens (C1q with C1r and C1s, and MBL with MBL-associated serine proteases: MASP-1, MASP-2) to form the C1 and MBL-MASPs complexes, respectively. As the recognition subunits bind to activator structures, subsequent activation of the serine protease zymogens occurs. The precise structure of the complexes and the exact mechanism of their activation have not been solved, yet. In this review we summarize the recent advances about the structure and function of the individual subcomponents of both complexes achieved by genetic engineering, molecular modeling, physico-chemical and functional studies. Special emphasis will be laid on the serine proteases: the role of the individual domains in the assembly of the C1s-C1r-C1r-C1s tetramer and in the control of the protease activity will be discussed. We will then focus on recent functional models of the supramolecular complexes. The question of how a non-enzymatic signal (the binding of C1q or MBL to activators) can be converted into enzymatic events (activation of serine protease zymogens) will be addressed. The similarities and differences between C1 and MBL-MASPs will also be discussed.

Complement Activation↗