[Influence of Anterior Cruciate Ligament Reconstruction on Gait Kinematics]

INTRODUCTION The anterior cruciate ligament (ACL) reconstruction is a tried and tested method in treating knee joint instability which brings valuable results in an acceptable time frame. In the long-term follow-up, however, a higher risk of knee osteoarthritis development is described. One of the possible reasons is considered to be the abnormal kinematics of the operated knee. The purpose of our study was to determine the degree to which the ACL reconstruction helps restore the correct gait cycle compared to the healthy limb. MATERIAL AND METHODS The study included patients after the ACL reconstruction performed in the period from 1 January 2016 to 31 March 2018. With the use of strict criteria, 11 patients were selected for kinematic analysis, who underwent examinations in a gait laboratory and were also evaluated using the Tegner and Lysholm rating systems and the IKDC (International Knee Documentation Committee) knee score, namely preoperatively and at 6 and 12 months postoperatively. The kinematic assessment of gait was carried out using the Vicon MX system with the placement of reflexive markers in line with the Plug-In Gait model. RESULTS The clinical outcomes (namely the score according to Tegner, Lysholm as well as the IKDC) during the first year postoperatively showed a major improvement in knee function and the achievement of the pre-injury activity level. The kinematic analysis revealed lower knee extension at the stance phase and lower overall range of motion of the limb with the injured ACL compared to the healthy limb. The follow-up evaluation at 6 and 12 months postoperatively showed a persisting between-limbs difference in knee extension, whereas the range of motion gradually improved during the year. CONCLUSIONS Although our study confirmed that the ACL reconstruction is an efficient method to treat knee joint instability, it also indicated that even at one year after the ACL reconstruction, the kinematics of the operated knee was not fully restored to the level of the heathy knee. The persisting limb-difference in gait kinematics could contribute to the gradual development of degenerative changes in the operated knee joint. Key words: anterior cruciate ligament deficiency, anterior cruciate ligament reconstruction, knee kinematics during gait, knee osteoarthritis.

[Effect of Primary and Revision Total Hip Arthroplasty on Gait Kinematics]

PURPOSE OF THE STUDY The number of patients with total hip arthroplasty (THA) has been growing. In addition to traumatic indication, the patients manifest abnormalities in kinematics and kinetics of gait preoperatively. The aim of the study was to assess kinematics of the pelvis and lower limbs during walking in patients with unilateral primary and revision THA. MATERIAL AND METHODS A total of 18 patients (10 females, 8 males) with primary THA (pTHA) as well as 18 patients (9 males, 9 females) with revision THA (rTHA) participated in the study. The control group (CON) comprised 19 healthy subjects (11 females, 8 males). Kinematic data were collected using the optoelectronic motion system Vicon MX. Kinematic parameters were obtained by means of 16 reflective markers placed on the patient's body in correspondence with the Plug-in Gait model. All the patients also underwent a clinical examination (evaluation of the surgery result, patient's satisfaction assessment, Harris score evaluation) and a specific X-ray evaluation of both hips. RESULTS The analysis brought the following results: - non-operated limb (NL) in pTHA vs. rTHA: significantly smaller total range of motion (ROM) in the hip joint (36.4° vs 41.7°) in the sagittal plane, - operated limb (OL) in pTHA vs. rTHA: significantly greater values of maximum knee flexion (14.2° vs. 9.8°) and extension (7.9° vs. 4.0°), - NL in pTHA vs. CON: significantly smaller ROM in the knee (51.0° vs. 57.9°) and hip (36.4° vs. 43.6°) joints in the sagittal plane, - OL in pTHA vs. CON: significantly smaller knee flexion (52.9° vs. 57.6°), hip extension (-0.6° vs. -10.4°), and the total ROM in the knee (51.5° vs. 57.9°) and hip (34.5° vs. 43.6°) joints in the sagittal plane, - NL in rTHA vs. CON: significantly greater pelvis ROM in both the sagittal (5.6° vs. 3.1°) and transverse (12.1° vs. 9.9°) planes, - OL in rTHA vs. CON: significantly smaller total ROM in the knee (48.9° vs. 57.9°) and hip (31.4° vs. 43.6°) joints in the sagittal plane. DISCUSSION After THA surgery, various gait pathologies as well as compensatory mechanisms can develop and chain; therefore, a complex approach to physical therapy in THA patients is needed. The number of significant differences found in kinematic parameters between pTHA and rTHA was low a year after the surgery. Compared to CON, both the THA groups exhibited similar mechanisms causing worsening their gait dynamics. CONCLUSIONS Gait in both the THA groups was characterized by a decreased ROM in the knee and hip joints in the sagittal plane, compensated by increased pelvic anteversion. Approximately one year after THA surgery, the NL is still noticeably dominant in gait. The changes in lower limb mechanics after revision THA persist even after a considerable time since the surgery. Key words: primary total hip arthroplasty, revision total hip arthroplasty, gait, range of motion, pelvic kinematics, biomechanics.

[Effect of Unloading Knee Brace on Dynamic Parameters of the Stance Phase of Gait in Patients with Knee Osteoarthritis]

PURPOSE OF THE STUDY Knee joint is the most common place where osteoarthritis may occur. A specific therapy is indicated to patients depending on the degree of disability and other signs. The available methods and their clinical value are regularly assessed in systematic reviews and meta-analysis of clinical studies. The evidence of working mechanism of the specific therapeutic intervention is another important part of evaluating its therapy effect. One of the possibilities of knee osteoarthritis conservative treatment is a functional prophylactic knee brace. This type of knee brace is designed to transfer the load away from the affected part of the knee joint in every step. The main goal of this study was to determine the effect of a prophylactic knee brace on dynamic parameters of the stance phase of gait in patients with knee osteoarthritis. MATERIAL AND METHODS The research involved twelve subjects with predominantly unilateral medial knee osteoarthritis of grade 2 and 3. Six patients did not complete the study. Therefore, the data of six persons were processed (average age 68.3 ± 4.4 years, average weight 83 ± 15.9 kg, average height 170.5 ± 11.7 cm). There were two piezoelectric Kistler 9286AA force plates used to determine the reaction forces. In total, six attempts were evaluated - three attempts with the knee brace and three attempts without it. Each subject completed three measurements. The first one took place at the beginning of the research, the second one after three months of using the brace, and the last one took place three months after the brace removal. The data processing methods were accustomed. At the beginning and at the end of the study the patients completed the WOMAC questionnaire and determined the level of their pain on the visual analogue scale (VAS). RESULTS The minimum value (p = 0.020) and the second maximum value (p = 0.035) of vertical reaction force significantly increased on the unaffected limb after a short-term application of a knee brace. There were significant increases found for walking without a brace in the maximum vertical force in the braking phase on the affected limb (p = 0.006) after three months of bracing, followed by similar results in the maximum vertical force in the braking (p = 0.001) as well as the propulsion (p = 0.035) phase on the unaffected side. Furthermore, we observed a significant extension in the overall duration of the stance phase of gait (p = 0.001) on the affected limb. According to the WOMAC and VAS results, three patients experienced subjective conditional improvement, two subjective deterioration and one participant remained unchanged. DISCUSSION The individualized solutions, i.e. their "adaptation" to a particular type of knee arthrosis in each patient, is the biggest problem in the treatment of knee arthrosis using a prophylactic brace. Our results confirm the usefulness of modern knee orthosis in terms of motion biomechanics. However, it still remains to be proved that it is possible to use the brace for a long time during the active time of the day and that this use brings about a significant relief from troubles, improving the patient's quality of life. CONCLUSIONS The effect of the orthosis application was reflected in force and time parameters of the vertical and anteroposterior component of the reaction force. The use of a prophylactic knee brace can influence the dynamics of gait. The short-term effect of prophylactic brace use is reflected in an increased load on the unaffected limb. From a long-term point of view, a prolongation of the stance phase in both extremities was observed. However, the positive effect of the knee brace use tended to persist even after the brace removal. There were no significant changes in the subjective assessment of pain, stiffness and function of the knee joint. Key words: osteoarthritis, knee joint, knee brace, walking, dynamic analysis, adduction moment.

A NEW APPROACH TO THE ASSESSMENT OF RADON BARRIER PROPERTIES OF WATERPROOFING MATERIALS

New definitions of the radon resistance and radon transmittance of waterproofing materials are introduced. They are based on the real steady-state radon distribution within the materials. Both quantities can therefore be considered as suitable parameters for the design of radon-proof insulations. A comparison between the existing definitions and the new definitions of radon resistance showed that the existing definition significantly underestimates the real radon resistance for a thickness to diffusion length ratio >0.8. It has also been proven that materials with different radon diffusion coefficients but with the same thickness to diffusion length ratio do not have the same radon resistance.

Hallux valgus surgery affects kinematic parameters during gait

BACKGROUND

The aim of our study was to compare spatiotemporal parameters and lower limb and pelvis kinematics during the walking in patients with hallux valgus before and after surgery and in relation to a control group.

METHODS

Seventeen females with hallux valgus, who underwent first metatarsal osteotomy, constituted our experimental group. The control group consisted of thirteen females. Kinematic data during walking were obtained using the Vicon MX system.

FINDINGS

Our results showed that hallux valgus before surgery affects spatiotemporal parameters and lower limb and pelvis kinematics during walking. Hallux valgus surgery further increased the differences that were present before surgery. Specifically after hallux valgus surgery, the walking speed decreased even more (p=0.09, η²=0.19) while step time increased (p=0.002, η²=0.44) on both legs. The maximum ankle plantar flexion of the operated leg during toe-off decreased to a greater extend (p=0.03, η²=0.26). The asymmetry in the hip and the pelvis movements in the frontal plane (present preoperatively) persisted after surgery.

INTERPRETATION

Hallux valgus is not an isolated problem of the first ray, which could be just surgically addressed by correcting the foot's alignment. It is a long-term progressive malfunction of the foot affecting the entire kinematic chain of the lower extremity.

Kinematic quantification of gait asymmetry in patients with peroneal nerve palsy based on bilateral cyclograms

Nowadays, bipedal walking is undergoing extensive study. Several methods can be used in physiotherapeutic research for identifying defects in bipedal walking as a result of pathology of the musculoskeletal or nervous system. Our work focuses on studying asymmetry of walking based on synchronized bilateral knee-knee cyclograms. Participants presenting with peroneal nerve palsy and foot drop were included in the study. The bilateral cyclograms, also called angle-angle diagrams, were created to quantify gait asymmetry before and immediately after application of a brace. In order to quantify the asymmetry of human walking, we have described and tested the application of the method based on the inclination angle of the synchronized bilateral cyclograms. The symmetry index (SI) was used as a comparative method to evaluate the symmetry of bipedal walking. The method based on the orientation of the cyclograms can be used as an additional method for determining the gait asymmetry. The new technique has never been applied before to study the gait asymmetry in patients with peroneal nerve palsy or patients with leg brace.

Use of controlled exogenous stress for improvement of poly(3-hydroxybutyrate) production in Cupriavidus necator

The PHB production by Cupriavidus necator H16 depends on the type and concentration of stress factors and on the time of stress application. Hydrogen peroxide and ethanol significantly enhanced PHB accumulation in C. necator cells. Improved yields (10.9 g/L PHB) were observed after exposure of bacterial culture to 0.5 mmol/L H2O2 at the beginning of cultivation and to additional peroxide stress (5 mmol/L H2O2) after 60 h of cultivation (beginning of the stationary phase). Production was then approximately 28 % higher than in control (8.50 g/L PHB). The highest yields (11.2 g/L PHB) were observed when ethanol (0.5 %) was applied at the beginning of stationary phase. An application of exogenous stress could thus be used as a simple strategy for a significant improvement of PHB production in C. necator.

Comparative transcriptome maps: a new approach to the diagnosis of colorectal carcinoma patients using cDNA microarrays

The progression of colorectal cancer involves accumulation of various genetic and epigenetic events that dramatically change gene expression. The aim of this study was to investigate a possible new approach to the diagnosis of colorectal carcinoma patients, based on their gene expression profiles. Human 19K cDNA microarrays were used to analyze the gene expression profiles of 18 colorectal carcinoma patients. Transcriptome maps (TMs) were analyzed to detect chromosomal regions that could serve as potential diagnostic markers for colon cancer. A comparison of TMs showed chromosome regions with conserved changes of gene expression typical of colorectal cancer in general, and also patient-specific variable regions. We identified 195 genes with significantly altered expression in colon cancer. Functional analysis of the regulated genes distinguished three main categories: biological processes, cellular components, and molecular functions. We found that different patients had chromosome regions characterized by very similar changes of gene expression, probably linked to the most fundamental events in carcinogenesis. On the other hand, variable chromosome regions can be patient-specific. The variable regions may provide further information on the individual pathogenesis and prognosis of the patient. Comparison of TMs is proposed as a tool to facilitate diagnosis and treatment planning for individual patients.

Identification and determination of phase II nabumetone metabolites by high-performance liquid chromatography with photodiode array and mass spectrometric detection

Chromatographic analyses play an important role in the identification and determination of phase I and phase II drug metabolites. While the chemical standards of phase I metabolites are usually available from commercial sources or by various synthetic, degradation or isolation methods, the phase II drug metabolites have usually more complicated structures, their standards are in general inaccessible and their identification and determination require a comprehensive analytical approach involving the use of xenobiochemical methods and the employment of hyphenated analytical techniques. In this work, various high-performance liquid chromatography (HPLC) methods were employed in the evaluation of xenobiochemical experiments leading to the identification and determination of phase II nabumetone metabolites. Optimal conditions for the quantitative enzymatic deconjugation of phase II metabolites were found for the samples of minipig bile, small intestine contents and urine. Comparative HPLC analyses of the samples of above-mentioned biomatrices and of the same biomatrices after their enzymatic treatment using beta-glucuronidase and arylsulfatase afforded the qualitative and quantitative information about phase II nabumetone metabolites. Hereby, three principal phase II nabumetone metabolites (ether glucuronides) were discovered in minipig's body fluids and their structures were confirmed using liquid chromatography (LC)-electrospray ionization mass spectrometric (MS) analyses.

Comparative biotransformation and disposition studies of nabumetone in humans and minipigs using high-performance liquid chromatography with ultraviolet, fluorescence and mass spectrometric detection

The disposition of the non-steroidal anti-inflammatory drug (NSAID) nabumetone after a single oral dose administration of nabumetone tablets to humans and minipigs was investigated. Nabumetone is a prodrug, which is metabolized in the organism to the principal pharmacodynamically active metabolite -- 6-methoxy-2-naphthylacetic acid (6-MNA), and some other minor metabolites (carbonyl group reduction products, O-desmethylation products and their conjugates with glucuronic and sulphuric acids). Standards of the above-mentioned metabolites were prepared using simple synthetic procedures and their structures were confirmed by NMR and mass spectrometry. A simple HPLC method for the simultaneous determination of nabumetone, 6-MNA and the other metabolites was developed, validated and used for xenobiochemical and pharmacokinetic studies in humans and minipigs and for distribution studies in minipigs. Naproxen was chosen as the internal standard (I.S.), both UV (for higher concentrations) and fluorescence detection (for very low concentrations) were used. The identity of the nabumetone metabolites in biological samples was confirmed using HPLC-MS experiments. Pharmacokinetics of nabumetone, 6-MNA and 6-HNA (6-hydroxy-2-naphthylacetic acid) in human and minipig plasma was evaluated and compared. The concentration levels of nabumetone metabolites in urine, bile and synovial fluid were also evaluated.

High-performance liquid chromatographic determination of tramadol and its O-desmethylated metabolite in blood plasma. Application to a bioequivalence study in humans

Simultaneous HPLC determination of the analgetic agent tramadol, its major pharmacodynamically active metabolite (O-desmethyltramadol) in human plasma is described. Simple methods for the preparation of the standard of the above-mentioned tramadol metabolite and N1,N1-dimethylsulfanilamide (used as the internal standard) are also presented. The analytical procedure involved a simple liquid-liquid extraction of the analytes from the plasma under the conditions described previously. HPLC analysis was performed on a 250x4 mm chromatographic column with LiChrospher 60 RP-selectB 5-microm (Merck) and consists of an analytical period where the mobile phase acetonitrile-0.01 M phosphate buffer, pH 2.8 (3:7, v/v) was used, and of a subsequent wash-out period where the plasmatic ballast compounds were eluted from the column using acetonitrile-ultra-high-quality water (8:2, v/v). The whole analysis, including the equilibration preceding the initial analytical conditions lasted 19 min. Fluorescence detection (lambda(ex) 202 nm/lambda(em) 296 nm for tramadol and its metabolite, lambda(ex) 264 nm/lambda(em) 344 nm for N1,N1-dimethylsulfanilamide) was used. The validated analytical method was applied to pharmacokinetic studies of tramadol in human volunteers.

High-performance liquid chromatographic determination of ursodeoxycholic acid after solid phase extraction of blood serum and detection-oriented derivatization

Ursodeoxycholic acid (3 alpha,7 beta-dihydroxy-5 beta-cholanoic acid, UDCA) is a therapeutically applicable bile acid widely used for the dissolution of cholesterol-rich gallstones and in the treatment of chronic liver diseases associated with cholestasis. UDCA is more hydrophilic and less toxic than another therapeutically valuable bile acid, chenodeoxycholic acid (CDCA), the 7 alpha-epimer of UDCA. Procedures for sample preparation and HPLC determination of UDCA in blood serum were developed and validated. A higher homologue of UDCA containing an additional methylene group in the side chain was synthetized and used as an internal standard (IS). Serum samples with IS were diluted with a buffer (pH=7). The bile acids and IS were captured using solid phase extraction (C18 cartridges). The carboxylic group of the analytes was derivatized using 2-bromo-2'-acetonaphthone (a detection-oriented derivatization), and reaction mixtures were analyzed (HPLC with UV 245 nm detection; a 125--4 mm column containing Lichrospher 100 C18, 5 microm; mobile phase: acetonitrile--water, 6:4 (v/v)). Following validation, this method was used for pharmacokinetic studies of UDCA in humans.

Study of the biotransformation of benfluron using the isolated perfused rat liver

The isolated perfused rat liver method (IPRL) was used to find, isolate and identify further metabolites of Phase I and Phase II biotransformation of the potential cytostatic agent benfluron with special regard to the conjugation processes. Its pharmacokinetic profile during the perfusion was also estimated. The rat liver was isolated from the body and perfused in vitro using a recirculating perfusion system. Benfluron was added to the reservoir as a bolus in doses of 200, 100, 30 mg/kg of body weigh and 1 mg/perfusate volume and also as a continual infusion in a dose of 0.1 mg/min in separate series of experiments. The following metabolites formed during Phase I biotransformation were found in the perfusion liquid as well as in the bile: benfluron N-oxide, 9-hydroxy benfluron, demethylated 9-hydroxy benfluron, demethylated benfluron, and reduced benfluron. The major Phase II metabolite found in the bile samples was the glucuronide of 9-hydroxy benfluron. The pharmacokinetic profile of benfluron in IPRL indicated its main disposition and metabolic pathway, i.e. its rapid extraction from perfusate by the liver (t1/2 alpha = 3.76 min), 9-hydroxylation followed up O-glucuronidation and excretion to the bile. It was revealed that 12% of the total dose of the parent compound was excreted to the bile in the form of conjugates during the first hour of perfusion, 32% during 1.5 hour, and 70% during 2 hours after the administration of benfluron. The conjugates with glucuronic acid represented 96-98% of all metabolites found in the bile.

Experimental Goettingen minipig and beagle dog as two species used in bioequivalence studies for clinical pharmacology (5-aminosalicylic acid and atenolol as model drugs)

Due to proven similarities in biotransformation between man and minipig, minipig seems to be the experimental animal of choice for preclinical pharmacokinetic studies when an experiment with a drug exhibiting a great first pass bioelimination (like 5-aminosalicylic acid) is to be realised. On the other hand, both minipig and dog may be suitable species for a pharmacokinetic study with a drug characterized by a small extent of first pass biotransformation (like atenolol).

Presence and activity of cytochrome P450 isoforms in minipig liver microsomes. Comparison with human liver samples

Cytochrome P450 (CYP) of the 3A family (CYP3A) has been detected in minipig liver microsomes by immunochemical screening (Western blotting), revealing bands that co-migrate with human CYP3A4 and 3A5. The nifedipine oxidase activity and testosterone 6beta-hydroxylating activity (specific markers for CYP3A enzymes) of the human liver microsomal and minipig liver microsomal samples were comparable, as were the results of specific inhibition of this activity by triacetyloleandomycin. The presence of CYP1A, 2A, 2C, 2D, and 2E1 marker activities in minipig liver microsomes was found by testing with the respective specific substrates (7-ethoxyresorufin, coumarin, tolbutamide, bufuralol, and chlorzoxazone). 7-Pentoxyresorufin O-depentylase activity (indicative of CYP2B) was absent from minipig as well as human liver microsomal samples. The results indicate that minipigs might be, in many cases, the most suitable experimental animals to predict biotransformation pathways in humans, because the activity of the most important CYP isoform in humans (CYP3A, metabolizing the majority of known drug substrates) is present in minipigs, with comparable levels and activities. Moreover, there is no need to induce CYP enzyme levels.

Preclinical comparison of bis-diketopiperazine-propane (dexrazoxane) and bis-diketopiperazine-ethane (antimet) on the adriamycin-cardiotoxic effect

A cardiotoxic effect induced by adriamycin (by repeated i.v. administration to experimental rats in 7-day intervals of administration) begins to be manifested in the ECG record by prolongation of the S alpha T segment between days 14 and 20, on day 30 it is statistically significant. By means of this index, the known protective effect of dexrazoxane (the preparation Cardioxan) against adriamycin cardiotoxicity has been successfully confirmed in a four-week experiment. A comparative study (using the identical frequency of the dosing scheme and S alpha T segment as the decisive parameter) has revealed that antimet-as another original substance of the diketopiperazines group-also involves (though less significantly) protective effects against the toxic action of adriamycin.

Study of the biotransformation of a potential benzo[c]fluorene antineoplastic using high-performance liquid chromatography with high-speed-scanning ultraviolet detection

As the sum of benfluron metabolites found was only a part of the total amount applied, a search for undiscovered metabolites was undertaken in the extracts from isolated rat hepatocytes and in the bile and perfusate in the experiments with an isolated perfused rat liver. To identify the metabolites, high-performance liquid chromatography with UV spectral analysis was used, as benfluron derivatives exhibit characteristic absorption spectra. Administration of known metabolites to experimental animals and selective induction of certain metabolic pathways led to the finding of new metabolites and of the respective conjugates. Fast atom bombardment-mass spectrometry analysis was used to identify the newly found metabolites and conjugates.

[An unusual case of prolonged hypoglycemia]

The author described a case of protracted hypoglycaemia in a young type I insulin treated diabetic, associated at first with neurological symptomatology imitating a cerebrovascular attack. After three days, when it was necessary to administer repeatedly glucose by the i.v. route on account of low blood sugar levels, the carbohydrate metabolism deteriorated and called for administration of similar insulin doses as before. In the discussion the author deals with pathogenetic possibilities of the described condition.

[Evaluation of glycosuria in normal glucose tolerance]

In 52 subjects where after 10.6 +/- 7 years after detection of glycosuria on fasting normal glucose tolerance persists some risk factors and early biochemical changes indicating possible later development of diabetes were evaluated. 73% of the subjects had a positive family-history of diabetes and 61% were obese. In 42% of the subjects during the present examination glucose in urine was detected only after a glucose load. In 35% of the subjects pathological serum values of glycoproteins were found and their mean fasting blood sugar levels and levels 60 minutes after a glucose load were significantly higher, although in the range of normal oGTT, as compared with the group with normal glycoprotein levels. 21% had pathological values of N-acetyl-beta-D-glucosaminidase levels in serum and urine and concurrently significantly higher IRI values 60 and 120 minutes after a glucose load, than the group with a normal value. In obese subjects, as compared with those with a normal body weight, there were significantly higher mean blood sugar levels on fasting and 60 minutes after a glucose load and the same applies to IRI levels on fasting and after 60 minutes following stimulation. The authors discuss the causes and interrelations of the assembled results.