[Assessing the Correlation between the Radiological, Macroscopic and Histological Examination of Degenerative Changes of Articular Surfaces in Knee Osteoarthritis with Varus Deformity]. / Hodnocení korelace mezi rentgenologickým, makroskopickým a histologickým hodnocením degenerativních zmen kloubních ploch u gonartrózy s varózní deformitou.

PURPOSE OF THE STUDY: Our study aims to compare the results of preoperative radiography and intraoperative visual assessment of the cartilage with histological assessment of joint surfaces of the medial and lateral compartments resected in patients during the total knee replacement. MATERIAL AND METHODS: The cohort included 20 patients (9 men and 11 women) with the mean age of 66.6 (±7.0) years who met the inclusion criteria of the study. Degenerative changes of the knee joint seen on a preoperative weight-bearing anteroposterior X-ray were evaluated according to the Kellgren-Lawrence grading system separately for the medial and lateral compartment. Based on the visual appearance, the condition of articular surfaces was assessed using the International Cartilage Repair Society Score (ICRS Grade). The histological assessment of degenerative changes was conducted by a pathologist with the use of the Osteoarthritis Research Society International Osteoarthritis Cartilage Histopathology Assessment System based on six grades of articular cartilage degeneration. RESULTS: The mean degree of degenerative changes based on the radiological classification was assessed as 3.5 (±0.6) for the medial compartment and 2.1 (±0.4) for the lateral compartment. The visually assessed chondropathy according to the ICRS Grade was 3.7 (±0.6) for the medial femoral condyle and 1.8 (±1.0) for the lateral femoral condyle. The histological score obtained using the Osteoarthritis Research Society International Osteoarthritis Cartilage Histopathology Assessment was 4.9 (±1.1) for the medial femoral condyle and 2.4 (±0.7) for the lateral femoral condyle. In respect of the medial compartment, there was no statistically significant parametric correlation between the intraoperative visual assessment of the cartilage degeneration and the preoperative radiological grade r = 0.45. The histological assessment showed a statistically significant concordance both with the degree of chondropathy r = 0.76 and the radiological grade r = 0.64. In the lateral compartment, the parametric test showed a statistically significant concordance only between the radiological grade and the histological score r = 0.72. The correlation between the visual assessment of chondropathy and the radiological grade r = 0.27 as well as the histological score r = 0.24 was very low. DISCUSSION: In our cohort assessing the early degenerative changes of the lateral compartment as well as the more advanced degenerative changes of the medial compartment, the correlation between the intraoperative assessment of cartilage degeneration as a diagnostic method to examine the lateral compartment and the preoperative radiological grade was not confirmed. Our results failed to confirm a better reporting value of the visual cartilage degeneration assessment of the lateral compartment as against the preoperative X-ray. The space width without narrowing on an X-ray has no reporting value for this compartment in case of varus deformity. CONCLUSIONS: The results clearly indicate that the assessment of macroscopic appearance of the cartilage degeneration during arthroscopy does not necessarily guarantee good long-term clinical outcomes after high tibial osteotomy. The respective degrees of cartilage degeneration identified during the intraoperative visual assessment and the radiological grading of osteoarthritic changes did not correlate in either compartment. In the lateral compartment, the initial radiological and histological findings preceded the visually detectable cartilage changes. KEY WORDS: knee, cartilage, osteoarthritis, radiology, histology, arthroscopy, osteotomy.

Thermodynamic Driving Forces of Redox-Dependent CPR Insertion into Biomimetic Endoplasmic Reticulum Membranes.

Cytochrome P450 reductase (CPR) is a NADPH-dependent membrane-bound oxidoreductase found in the endoplasmic reticulum (ER) and is the main redox partner for most cytochrome P450 enzymes. Presented are the measured thermodynamic driving forces responsible for how strongly CPR partitions into a biomimetic ER with the same lipid composition of a natural ER. Using temperature-dependent fluorescence correlation spectroscopy and fluorescence single-protein tracking, the standard state free energies, enthalpies, and entropies of the CPR insertion process were all measured. The results of this study demonstrate that the thermodynamic driving forces are dependent on the redox states of CPR. In particular, the partitioning of CPRox into a biomimetic ER is an exothermic process with a small positive change in entropy, while CPRred partitioning is endothermic with a large positive change in entropy. Both resulted in negative free energies and strong association to the biomimetic ER, but the KP of CPRox insertion is measurably smaller than that of CPRred. Using this new information and known results from literature sources, we also present a phenomenological model that accounts for membrane-protein interactions, protein orientation relative to the membrane, and protein conformation as a function of the redox state.

Direct Measurement of Single-Molecule Ligand-Receptor Interactions.

Measuring the kinetics that govern ligand-receptor interactions is fundamental to our understanding of pharmacology. For ligand-gated ion channels, binding of an agonist triggers allosteric motions that open an integral ion-permeable pore. By mathematically modeling stochastic electrophysiological responses with high temporal resolution (ms), previous single channel studies have been able to infer the rate constants of ligands binding to these receptors. However, there are no reports of the direct measurement of the single-molecule binding events that are vital to how agonists exert their functional effects. For the first time, we report these direct measurements, the rate constants, and corresponding free energy changes, which describe the transitions between the different binding states. To achieve this, we use the super resolution technique: points accumulation for imaging in nanoscale topography (PAINT) to observe binding of ATP to orthosteric binding sites on the P2X1 receptor. Furthermore, an analysis of time-resolved single-molecule interactions is used to measure elementary rate constants and thermodynamic forces that drive the allosteric motions. These single-molecule measurements unequivocally establish the location of each binding states of the P2X1 receptor and the stochastic nature of the interaction with its native ligand. The analysis leads to the measurement of the forward and reverse rates from a weak ligand-binding state to a strong ligand binding state that is linked to allosteric motion and ion pore formation. These rates (kα = 1.41 sec-1 and kß = 0.32 sec-1) were then used to determine the free energy associated with this critical mechanistic step (3.7 kJ/mol). Importantly, the described methods can be readily applied to all ligand-gated ion channels, and more broadly to the molecular interactions of other classes of membrane proteins.

[Good's syndrome (thymoma associated hypogammalobulinaemia) - 2 case reports]. / Gooduv syndrom (s thymomem spojená hypogamaglobulinemie) - 2 kazuistiky.

Although tumours of the thymus are rare, they are common among neoplasms of the anterior superior mediastinum. They usually exhibit indolent behavior, but do have the capacity to invade surrouding structures. Their metastatic potential is low. Paraneoplastic complications including autoimmune disorders (frequently myastenia, cytopenia) or combined immunodeficiency are of clinical significance. Here we report two case reports of thymoma patients associated with secondary immunodeficiency known as Goods syndrom. The first case exhibited as symptomatic combinated immunodeficiency with oral lichen planus. Thymoma findings was accidental. Severity of immunodeficiency required long-term intravenous immunoglobulins supplementations, even after complete surgical resection. On the other hand, the second case manifested by signs of advanced local tumour growth. Antibiotic prophylaxis was selected as immunodeficiency treatment.

Biodegradable stents for the treatment of benign stenoses of the small and large intestines.

Biodegradable stents, which are made of various synthetic polymers, such as polylactide or polyglycolide, or co-polymers, such as polydioxanone, can be used for the treatment of benign refractory stenoses of the gastrointestinal tract. Here we report 11 patients (median age 41) with stenosing Crohn's disease of the small and/or large intestine. Endoscopic insertion of a biodegradable stent was successful at the first attempt in all patients except one. Subsequent follow-up was for a mean of 16 months, median 17 months, range 12-29 months. Early stent migration (between 2 days and 8 weeks) was seen in three patients. Mucosal overgrowth (epithelial hyperplasia) was not observed in any of the patients during the follow-up period. The high rate of early stent migration might be solved by appropriate tailoring and further improvements in the design of the biodegradable stents. Proof of long-term efficacy and safety requires further studies.

Platelet activating factor antagonist design. 3. X-ray crystal structure and intermolecular crystal lattice interactions of methyl trans-4-acetoxymethyl-4,5-dihydro-2,5-bis(3,4-methylenedioxyphenyl)- 3-furancarboxylate.

C23H20O9, Mr = 440.41, monoclinic, P21/c, a = 11.433 (1), b = 7.808 (2), c = 23.313 (3) A, beta = 99.67 (1) degree, V = 2052 A3, Z = 4, Dx = 1.43 g cm-3, lambda(MoK alpha) = 0.71073 A, mu = 0.69 cm-1, F(000) = 920, T = 293 K, final R = 0.048 for 1645 observed [Fo greater than or equal to 5 sigma(Fo)] reflections. The observed structure reveals a trans relationship for the 4-acetoxymethyl and 5-aryl substituents. The 4,5-dihydrofuran ring system adopts an envelope conformation. There is no crystallographically imposed symmetry. Several intermolecular van der Waals interactions occur in the cell lattice of this compound.

[In situ hybridization of chorionic villi cells]. / Hybridizace in situ na bunkách choriových klku.

Two cloned alpha fragments of satellite repetitive DNA sequences were used to modify the method of DNA hybridization in situ (HIS) for tissue cells of human chorionic villi. Techniques for the cells of short-term lymphocytic cultures were used to optimize the conditions of HIS in chorionic villi cells with regard to a more specific localization of cloned repetitive DNA sequences in the target homologous chromosomes. A total of 262 specimens were prepared using the HIS method. As the results show, both cloned fragments are well applicable for routine cytogenic practice, the fragment p YAM 10-40 for the number of chromosomes, and fragment p YAM 9-72 for chromosomes 18.