Antisenescence effect of REAC biomodulation to counteract the evolution of myelodysplastic syndrome.

About 30 percent of patients diagnosed with myelodysplastic syndromes (MDS) progress to acute myeloid leukemia (AML). The senescence of bone marrow?derived mesenchymal stem cells (BMSCs) seems to be one of the determining factors in inducing this drift. Research is continuously looking for new methodologies and technologies that can use bioelectric signals to act on senescence and cell differentiation towards the phenotype of interest. The Radio Electric Asymmetric Conveyer (REAC) technology, aimed at reorganizing the endogenous bioelectric activity, has already shown to be able to determine direct cell reprogramming effects and counteract the senescence mechanisms in stem cells. Aim of the present study was to prove if the anti-senescence results previously obtained in different kind of stem cells with the REAC Tissue optimization - regenerative (TO-RGN) treatment, could also be observed in BMSCs, evaluating cell viability, telomerase activity, p19ARF, P21, P53, and hTERT gene expression. The results show that the REAC TO-RGN treatment may be a useful tool to counteract the BMSCs senescence which can be the basis of AML drift. Nevertheless, further clinical studies on humans are needed to confirm this hypothesis.

Liquid resorbable nanofibrous surgical mesh: a proof of a concept.

BACKGROUND: Surgical mesh is widely used not only to treat but also to prevent incisional hernia formation. Despite much effort by material engineers, the 'ideal' mesh mechanically, biologically and surgically easy to use remains elusive. Advances in tissue engineering and nanomedicine have allowed new concepts to be tested with promising results in both small and large animals. Abandoning the concept of a pre-formed mesh completely for a 'pour in liquid mesh' has never been tested before. MATERIALS AND METHODS: Thirty rabbits underwent midline laparotomy with closure using an absorbable suture and small stitch small bites technique. In addition, their abdominal wall closure was reinforced by a liquid nanofibrous scaffold composed of a fibrin sealant and nanofibres of poly-ε-caprolactone with or without hyaluronic acid or the sealant alone, poured in as an 'onlay' over the closed abdominal wall. The animals were killed at 6 weeks and their abdominal wall was subjected to histological and biomechanical evaluations. RESULTS: All the animals survived the study period with no major complication. Histological evaluation showed an eosinophilic infiltration in all groups and foreign body reaction more pronounced in the groups with nanofibres. Biomechanical testing demonstrated that groups treated with nanofibres developed a scar with higher tensile yield strength. CONCLUSION: The use of nanofibres in a liquid form applied to the closed abdominal wall is easy to use and improves the biomechanical properties of healing fascia at 6 weeks after midline laparotomy in a rabbit model.

PVA and PCL nanofibers are suitable for tissue covering and regeneration.

The aim of the study was to evaluate the safety and efficacy of a new therapeutic approach to skin defects resulting from split thickness grafting. Within the study, nanofiber-based dressings fabricated using polyvinyl alcohol (PVA) and poly-ε-caprolactone (PCL) were used, with different mass density. The study was performed in 1 female minipig. Nine defects (approx. 4x4 cm) were made in the superficial skin layer. The tested materials were applied to the squared skin defect and covered by a Jelonet paraffin gauze, sutured in the corners of the defects. The animal was monitored daily during the healing process (21 days). On day 5, 12, and 27, the healing of the wound was evaluated, and a biopsy was performed for further histologic testing. At the end of the study (on day 27 after the procedure), the animal was euthanized, and a standard pathologic evaluation was performed. We can conclude that the nanofiber scaffold which was well tolerated, could be used as a smart skin cover which could be functionalized with another bioactive substances directly on the surgeon table, among potential bioactive substances belong platelet derivatives, antibiotics, etc.

[Canine Elbow Humeroulnar Incongruity Measurements Using Computed Tomography]. / Merení humeroulnární inkongruity loketního kloubu u psu pomocí výpocetní tomografie.

PURPOSE OF THE STUDY The purpose of the study is to compare the repeatability and reproducibility of quantitative and subjective evaluation of elbow humeroulnar incongruity (HUI) using computed tomography (CT) on an in vivo canine model. MATERIAL AND METHODS HUI was evaluated on canine (n = 50) elbow joints (n = 100). The computed tomography of elbow joints was performed under intravenous sedation. Multiplanar reconstructions (MPR) were produced. HUI was evaluated on sagittal MPR images subjectively and by measuring the subluxation index (SI). The SI was defined by measuring the distance between the centres of two circles, the shape of which corresponded the most with the shape of the trochlear notch of the ulna at sagittal crest and the shape of humeral trochlea. This distance was divided by the radius of the circle (r) defining the humeral trochlea. HUI was subjectively evaluated based on the width of the joint space at the greatest caudal convexity of the trochlear notch of the ulna. Three categories of HUI were established: 0 (congruent), 1 (moderately incongruent), 2 (strongly incongruent). Measurement and evaluation of HUI was conducted by two evaluators twice at a one-month interval between the first and second measurement. The statistical analysis was carried out using the repeated measures ANOVA and the Cohen s kappa coefficient. RESULTS The mean SI was 11.14 (SD 8.703). The SI values measured by two evaluators were statistically significantly different (p < 0.05). Contrarily, there was no statistically significant difference between the two measurements of the same evaluator (p > 0.05). The subjective evaluation of HUI done by two evaluators showed a mean to substantial agreement (Kappa = 0.53-0.79). There was a substantial to almost perfect agreement between the results of two evaluations carried out by a single evaluator (Kappa = 0.79-0.83). DISCUSSION The radiographic detection of moderate incongruity is unreliable, especially on account of wrongly positioned elbow joint, superposition of bone structures and due to the evaluation of three-dimensional bone structure through a two-dimensional image. Evaluation of humeroulnar congruity by computed tomography (CT) enables to assess the congruity of joints without the superposition of neighbouring bone structures. The quantification of humeroulnar incongruity using the SI does not show a higher degree of agreement between two evaluators as against the subjective evaluation of HUI. On the contrary, the agreement between two measurements of a single evaluator was high in both the cases. CONCLUSIONS Dog is a suitable model animal for evaluation of HUI of elbow joints due to frequent incidence of elbow dysplasia associated with HUI. The quantification of HUI at the expense of subjective evaluation of HUI is often overrated in radiological studies. Key words: dog, elbow, humeroulnar incongruity.

[Persisting symptoms, diastolic dysfunction and decreased coronary flow reserve after succesful correction of aortic recoarctation]. / Pretrvávajúce symptómy, diastolická dysfunkcia a nízka koronárna rezerva u pacientky po úspesnej korekcii rekoarktácie aorty.

We present a case of a 53-year-old woman undergoing successful surgical treatment ofcoarcation restenosis after patch grafting in childhood. Despite the optimal result of the operation, normal left ventricle systolic function and coronary angiogram, majority of symptoms, such as angina and dyspnea, persist 16 months after the intervention. In further investigation, pathological values of left ventricular end-diastolic pressure (LVEDP = 30 mm Hg) and coronary flow reserve (CFR = 1.3) were confirmed, implicating recoarctation to be the unusual cause of cardiac syndrome X.

[Severance of the accessory bundle of Kent in a 13-year-old boy with Ebstein's anomaly of the tricuspid valve]. / Prerusení akcesorního Kentova svazku u 13-letého chlapce s Ebsteinovou anomalií trikuspidální chlopne.

In patients with Ebstein's anomaly of the tricuspid valve combined with WPW syndrome, possibly other cardiac disease, in particular with the repeated occurrence of severe tachydysrhythmias we can foresee cure or at least elimination of complaints by simultaneous surgical treatment of all defects. The author presents experience with the surgical treatment, the first of its kind in this country, in a boy aged 13 years. By better diagnosis it proved possible to locate correctly and to severe by surgery the abnormal accessory bundle between the right atrium and right ventricle, simultaneously with a plastic operation of the insufficient tricuspid valve with closure of the atrial septal defect. Since the operation the patient has no signs of ventricular preexcitation and has no tachydysrhythmias.

[Pericardial teratoma in an infant]. / Teratom perikardu u kojence.

In a four-month-old neonate a pericardial teratoma was diagnosed which exerted pressure on the airways, right atrium and large blood vessels. The tumour was removed by operation. It was a simple, mature pericardial teratoma. Supporting cytostatic treatment was administered. Three years after operation the patient is free of signs of relapse of the tumour.