Synthesis, Characterization, and Physicochemical Studies Of Orientation-Controlled Multi-Arm PEG Zn(II)/Mg(II) (Aza)Phthalocyanines.

Tuning the amphiphilicity of (aza)phthalocyanine hydrophobic cores by introducing multiple polyethylene glycol (PEG) moieties with controlled orientations of their (non)peripheral positions is an innovative approach to fabricating water-soluble macrocyclic materials. Although many water-soluble PEGylated macrocycles have been produced in this way, the ability to generate substances with PEG tails oriented outward from the macrocyclic plane in order to obtain non-aggregated, water soluble forms remains a challenge. In this study, we resolved this issue by developing a methods for the synthesis of four new dual directional PEG containing Zn(II)/Mg(II) amphiphiles (ZnPc-PEG, MgPc-PEG, ZnAzaPc-PEG and MgAzaPc-PEG). In addition, the non-aggregating behaviour, and photophysical and photochemical properties of these PEG-complexes were elucidated.

[Complications after Revision Total Knee Arthroplasties]. / Komplikace po revizních operacích totálních endoprotéz kolena.

PURPOSE OF THE STUDY The failure of arthroplasties and above all the issue of infection and its detection have become an ever more frequently discussed problem. The purpose of our study was to determine the frequency and the type of complications after revision total knee arthroplasties and to compare them with the frequency of complications after primary implantations. MATERIAL AND METHODS In our group of patients followed up in the period from January 2007 to December 2016, in 50 patients the revision surgery was performed for aseptic loosening and in 24 patients for deep infection. In the case of revision surgery for aseptic loosening, in 18 patients original sterilised components were used as a spacer, in 6 patients an articulating cement spacer was applied. Only the complications resulting in the performance of further revision were included in the statistics. A total of 13 patients underwent a primary implantation at another centre. The number of revisions and the reason for implant failure were monitored. The results were compared with the frequency of revision surgeries after primary total knee arthroplasty, of which 2,436 were carried out in the referred to period. RESULTS Of 2,436 primary endoprostheses, altogether 3.1 % failed. In 50 (2.1 %) patients aseptic loosening was reported, 24 patients (1 %) suffered from infection. The median time from primary implantation to revision was 11 years for aseptic loosening, 2 years for infection. The most frequent cause of failure was aseptic loosening. In the group of patients who underwent a revision surgery for aseptic loosening, another revision was necessary in 6 cases (12 %), in the group of patients after the two-stage revision surgery for infection, in 9 cases (37.5 %). The most frequent reason for revision surgery was infection - in both the groups this was the reason for 67 % of revision surgeries. DISCUSSION Our results obtained with respect to primary as well as revision surgeries for aseptic loosening correspond with the results reported by other authors. In the case of two-stage revision implantation, the reported frequency of recurrent infections is the same, the frequency of revision surgeries for aseptic causes is slightly lower in our group. The most frequent causes of revision surgery are also in agreement. In the case of primary implantation, the patients most frequently suffer from aseptic loosening, after revision surgeries another revision surgery is most often performed due to infection. The literature refers to studies suggesting the potential use of original components as a spacer with the same success rate as that achieved with the cement spacer. The original components produced good results in two thirds of two-stage revision implantations, which is why we can agree with these studies. CONCLUSIONS The results clearly show a noticeable increase in the frequency of complications in revision surgeries compared to primary surgeries. In comparison with primary implantations, a subsequent revision after the revision implantation for aseptic loosening was necessary three times more frequently, after the two-stage revision implantation for infection it was ten times more frequently. As the most problematic complication can be considered the infection in case of primary as well as revision interventions. It is obvious that aseptic loosening of the primary implant usually occurs later (the median of 11 years) than the development of deep infection (the median of 2 years). Key words: total knee arthroplasty, revision, failure, complications, aseptic loosening, infection, spacer.

[Evaluation of Efficacy of Systemic Administration of Tranexamic Acid (Exacyl) in Total Hip and Knee Arthroplasty - Prospective Cohort Study]. / Hodnocení úcinnosti systémového podání tranexamové kyseliny (Exacylu) u náhrad kycelního a kolenního kloubu ­ prospektivní kohortová studie.

PURPOSE OF THE STUDY To evaluate the efficacy of the systemic administration of two doses of tranexamic acid (TXA) in total knee (TKA) and hip arthroplasty (THA). MATERIAL AND METHODS The study evaluated a total of 295 patients who underwent total knee and hip arthroplasty for osteoarthritis, prospectively followed up were the patients who had been administered the tranexamic acid (TXA), and this group was subsequently compared against the cohort - control group. Our evaluation was focused on perioperative and postoperative period. The amount of blood loss was monitored during the surgery as well as postoperatively. Moreover, the frequency and the volume of administered allogeneic blood transfusions and in TKA also autotransfusion requirement were observed. The patients postoperative hemoglobin levels were compared in both the groups when the patients were in the ICU and the frequency of all postoperative complications was monitored. The statistical analysis was carried out separately for hip and knee replacement. RESULTS Our study confirmed that the systemic application of tranexamic acid in two 10-15 mg/kg doses in knee arthroplasty resulted in a statistically significant reduction of perioperative and postoperative blood loss, lower frequency of administration of allogeneic blood transfusion, but also in lower frequency in the administration of any transfusion, including autotransfusion. In patients who underwent total hip arthroplasty, the administration of TXA led to a statistically significant reduction of postoperative bleeding. The patients with total knee as well as hip arthroplasty, who had been administered TXA, showed significantly higher haemoglobin levels when transferred from the ICU. No significant difference was found in deep vein thrombosis, pulmonary embolism or other postoperative complications among the study groups. DISCUSSION There is no homogeneity in the already published studies proving the efficacy of TXA in TKA and THA, they differ considerably as to the method of administration of the tranexamic acid. The differences concern the systemic and local application, dosage and time of administration. In some studies, TXA was administered in a single dose only, whereas in other studies it was administered repeatedly, in the form of a bolus or continuously. In our study we confirmed the efficacy of systemic administration of tranexamic acid in two repeated bolus doses of 10-15 mg/kg, namely before the commencement of the surgery and at the end of the surgery. CONCLUSIONS The administration of tranexamic acid in two IV doses of 10-15 mg/kg to patients with total knee and hip arthroplasty has proven to be efficient. A higher efficacy of TXA was reported in TKA and due to routine administration of TXA the postoperative autotransfusion system (ORTHO P.A.S.) ceased to be used in knee replacement surgery. Key words:total hip arthroplasty, total knee arthroplasty, tranexamic acid, blood loss, allogeneic transfusion, autotransfusion, postoperative complications.

Anion exchange nanofiber materials activated by daylight with a dual antibacterial effect.

Anion exchange polystyrene nanofiber materials (AE) were prepared by electrospinning followed by two-step functionalization of the nanofiber surface by chlorosulfonic acid and ethylendiamine. The photoactive character of these materials was introduced through adsorption of the tetra-anionic 5,10,15,20-tetrakis-(4-sulfonatophenyl)porphyrin photosensitizer (TPPS-AE) on the nanofiber surface or by encapsulation of the nonpolar 5,10,15,20-tetraphenylporphyrin photosensitizer (AE(TPP)) into the nanofibers. Anion exchange nanofiber materials with porphyrins are characterized by a high ion-exchange capacity, photogeneration of singlet oxygen O2((1)Δg), and singlet oxygen-sensitized delayed fluorescence. Due to the photogeneration of cytotoxic O2((1)Δg), the nanofibers exhibited oxidation of the external substrates in aqueous solution and an efficient antibacterial effect when activated by simulated daylight. Adsorption of both TPPS and I(-) on the surface of AE led to the formation of more efficient I-TPPS-AE materials. Rapid photooxidation of I(-) by O2((1)Δg), and the formation of another cytotoxic species, I3(-), on the surface of the nanofibers were responsible for the increased antibacterial properties of I-TPPS-AE and the prolonged antibacterial effect in the dark.

[Maïa trapeziometacarpal implant for treatment of advanced osteoarthritis of the basal joint of the thumb]. / Trapézometakarpální endoprotéza Maia v lécbe pokrocilé artrózy korenového kloubu palce ruky.

PURPOSE OF THE STUDY: Osteoarthritis of the thumb's basal joint is a frequent and, in some cases, very painful condition that usually affects middle-aged and elderly women. Several surgical procedures have been proposed for severe carpometacarpal (CMC) joint arthritis; of these, joint replacement has proved to be an effective approach to its treatment. The aim of this study is to present the outcomes of the total non-cemented trapeziometacarpal implant Mada in the treatment of more advanced stages of this disease. MATERIAL AND METHODS: Thirty-six total trapeziometacarpal joint replacements in 34 patients treated in 2008 for advanced CMC arthritis (Eaton and Littler stages III and IV) were evaluated. Indications for surgery after failure of conservative treatment included: pain, reduced grip and pinch strength and restricted range of thumb motion, all of them interfering with daily activities. The average follow-up time was 42 months, with a minimum of 37 months. RESULTS: At the final follow-up, thumb opposition to the base of the little finger was present in all patients. The average grip strength of the hand increased from 15.8 kg pre-operatively to 26.8 kg post-operatively. The average key pinch strength increased from 2.7 kg to 5.7 kg and the average tip pinch strength from 2.3 kg to 4.9 kg. All patients reported substantial pain relief. The average VAS values were 8.4 points before surgery and 0.4 points at 3 years after surgery. Pre- and post-operative DASH scores were 71.7 and 22.5, respectively. One patient had aseptic cup loosening that required revision surgery. No signs of implant loosening in any other patient were shown by radiographic studies at the final follow-up. One patient sustained a traumatic implant dislocation that was treated by open reduction. DISCUSSION: Total replacement of the CMC joint is a method with functional outcomes comparable with or better than other surgical procedures. Rapid post-surgery recovery is its clear advantage. The implant provides good stability and no prolonged immobilisation is needed. CONCLUSIONS: In our group, total arthroplasty of the thumb CMC joint provided pain relief, improved thumb motion and pinch strength. At present, CMC joint arthroplasty is recommended to elderly patients with symptoms of advanced arthritis (stage III or early stage IV) refractory to conservative treatment or to well-informed younger persons accepting reduced demands on the treated hand's activities.

[Biomechanical parameters and clinical outcomes of the Oxford Phase III unicompartmental knee replacement]. / Biomechanické parametry a klinické výsledky unikompartmentální náhrady Oxford Phase III.

PURPOSE OF THE STUDY: The kinematics of an intact knee joint and that of a knee replacement have been studied in many research centres. In the 1987 radiographic study, Bradley, Goodfellow and O'Connor reported the movement of a polyethylene insert in patients with unicompartmental Oxford knee replacement. Views with the knee at full extension and 90° of flexion were obtained and the movement of the meniscal bearings over this range of flexion was measured. The bearings were found to move backwards on the tibia through an average distance of 4.4 mm in all 16 patients. This measurement was in agreement with the then valid concept of knee biomechanics and a roll-back phenomenon. However, our observations had not always agreed with the results of these authors, but gave an impetus for a detailed evaluation of our own patient group. The aim of the study was to evaluate the dynamic relationship between the components of a unicompartmental Oxford knee replacement and elucidate it with the use of recent information from the field of biomechanics. A relationship of the obtained kinematic values to clinical outcomes was also investigated. Answers to the following hypotheses were sought: Would our results be in agreement with the British authors' findings? Would clinical outcomes depend on the kinematic properties of knee replacements? MATERIAL AND METHODS: The group comprised 33 patients, 23 women and 10 men. They all had replacement of the medial compartment of the knee. The construction of the unicompartmental Oxford Phase III knee replacement enabled us to locate the centre of rotation of the medial femoral condyle in relation to the tibial component at flexion and extension of the knee, using radiography. The patients were examined in a supine position with the knee at full extension, and subsequently views of the knee were obtained at 80°-90° flexion in accordance with the method used by the British authors. The clinical findings of knee joints were assessed using the American Knee Society (AKS) scoring system (Insall et al.). Pain was rated on the Visual Analogue Scale (VAS). The results were statistically evaluated with the t-test and Chi-square test. RESULTS: On moving the knee from extension to flexion, movement of the polyethylene insert ventrally by an average of 3.4 mm in relation to the tibia was recorded, i.e., "paradoxical" ventral translocation. In the patients with insert movement less than or equal to 3 mm, the average AKS score was 89 points, in those with movement over 3 mm it was 87 points. The average functional scores were 87 and 83 points in the patients with movement less than 3 mm and more than 3 mm, respectively. The average VAS score was 1.55 in the former and 1.18 in the latter. DISCUSSION: The unicompartmental Oxford Phase III knee replacement substitutes a flexion femoral facet and eliminates the role of an extension femoral facet. This is the reason why, at knee extension between -5° and +20°, the centre of rotation of the medial femoral condyle is in the centre of the flexion facet and not in that of the extension facet. When the stabilising functions of the extension tibial facet in the ventral direction and of the dorsal part of the insert in the dorsal direction are missing, the position of the contact surface centre becomes much dependent also on the strength and direction of external forces acting in the knee joint vicinity. CONCLUSIONS: The kinematic parameters of the unicompartmental Oxford Phase III knee replacement investigated in our group differed from the findings of the British authors. However, neither the magnitude nor the direction of movement had any effect on the clinical outcome of knee arthroplasty.

Dispersion of light and heavy pollutants in urban scale models: CO(2) laser photoacoustic studies.

The distribution of pollutants in two urban scale models (point emission source and street canyon with extensive transport) was investigated by means of CO(2) laser photoacoustic spectroscopy in the region of the atmospheric window (9-10 mum). The experimental results of physical modeling are in a good agreement with the numerical calculations performed in the frame of computational fluid dynamic (CFD) modeling. Methanol, ethanol, and ozone (examples of light pollutants), as well as sulfur hexafluoride and 1,2 dichlorethane (examples of heavy pollutants), were selected on the basis of their high resolution spectra acquired by Fourier transform and laser diode spectroscopy.

[Long-term results of unicompartmental knee joint replacement]. / Dlouhodobé výsledky unikompartmentální náhrady kolenního kloubu.

PURPOSE OF THE STUDY: To evaluate the long-term results of unicompartmental knee joint alloplasty (UKA) in a group of 21 patients. On the basis of their own results and literature data, the authors discuss effective strategies for treatment of unicompartmental osteoarthritis of the knee joint. MATERIAL: A group of 21 patients, who were implanted a total of 22 unicompartmental knee replacements, type St. Georg, Waldemar Link, between 1986 and 1992, were followed-up till 2002. Since two patients living permanently abroad were excluded, the group at the final evaluation consisted of 19 patients with a total of 20 knee replacements. METHODS: In 2002, all patients were clinically and radiologically examined. They were interviewed about their subjective evaluation of the knee joint after alloplasty, and clinical and functional findings were assessed. The evaluation of long-term results was based on The Knee Society Clinical Rating System. RESULTS: The average Knee Score value was 84 points and average Function Score value was 78 points. Out of the 20 knee replacements evaluated, only one failure of UKA was recorded at 9 years after the primary implantation. DISCUSSION: The authors discuss the current state of treatment in unicompartmental knee arthritis and present several different views based on literature sources. Opinions on indications for specific surgical methods are still controversial. The authors draw attention to comparisons of long-term results between patients with UKA and patients who underwent high tibial valgus osteotomy or total knee replacement. They discuss the advantages and disadvantages of UKA in comparison with the other therapies. They also pay some attention to repeat surgery in failed UKA. CONCLUSIONS: UKA implantation is a surgical method of managing unicompartmental arthritis of the knee joint. The results presented by the authors and corroborated by many literature data provide evidence that UKA is of great importance in the treatment of unicompartmental knee arthritis. If a consistent selection of patients is maintained, a precise operation technique is used and a reliable implant is chosen, excellent immediate as well as long-term outcomes will be achieved.

Photophysical properties and photoinduced electron transfer within host-guest complexes of 5,10,15,20-tetrakis(4-N-methylpyridyl)porphyrin with water-soluble calixarenes and cyclodextrins.

We report the formation of host-guest complexes between water-soluble calix[n]arene-p-tetrasulfonates (n = 4, 6, 8) or 2-hydroxypropyl-cyclodextrins (alpha-, beta-, gamma-) and the tetratosylate salt of 5,10,15,20-tetrakis(4-N-methylpyridyl)porphyrin (TMPyP). The binding constants ranging between 10(2) and 10(5) M-1 were calculated from the absorption and fluorescence changes. Calix[4]arene-p-tetrasulfonate has a high binding affinity and forms with TMPyP a 1:1 complex, whereas other calixarenes bind two molecules of TMPyP. Electrostatic attraction is the dominating binding mode. Binding to calixarenes leads to a considerable decrease of the quantum yields of the triplet and excited singlet states and to shortening of the singlet and triplet lifetimes of TMPyP. The quenching mechanism is attributed to electron transfer between calixarene phenolates and excited TMPyP. Photoinduced electron transfer within a novel supramolecular complex calixarene/TMPyP (electron donor)/methyl viologen (electron acceptor) has been proven by absorption and fluorescence measurements. Electrostatic attraction between the cationic donor and cationic acceptor, on the one hand, and the anionic host, on the other, overcomes the electrostatic repulsion forces. In contrast, the interaction of cyclodextrin with TMPyP is hydrophobic in nature and only slightly influences the photophysical properties of TMPyP. The different behavior of TMPyP bound to either of the hosts has been assigned to the specific effects of the dominant binding modes, viz. the electrostatic attraction for calixarenes and the hydrophobic interactions for inclusion complexes with cyclodextrins.

Long-range assemblies on poly(dG-dC)2 and poly(dA-dT)2: phosphonium cationic porphyrins and the importance of the charge.

The present paper describes synthesis and spectroscopic properties of novel cationic meso-tetraphenylporphyrins bearing two (trans) (P2) or three (P3) triphenylphosphonium substituents. The porphyrin aggregation in aqueous solutions is discussed in detail. Porphyrin binding to and self-organization onto long-range assemblies on poly(dA-dT)2 or poly(dG-dC)2 were probed by combination of absorption, fluorescence, circular dichroism (CD), transient and resonance light-scattering (RLS) techniques. The higher hydrophobicity of P2 is manifested by more extensive self-organization. Induced CD and intensive RLS indicate binding to the chiral environment on the nucleic acids exterior and exciton coupling between adjacent porphyrin moieties. The CD spectra of P2 on poly(dG-dC), and poly(dA-dT)2 suggest that the binding geometry is essentially independent of the base sequence. The fluorescence lifetime of about 4 ns was attributed to the long-range assembly. In the case of P3 the distinctly different CD spectra induced by GC or AT base-pair regions reveal that the number of the substituents determines how closely the porphyrin can approach the specific electronic environment on the nucleic acid exterior. The fluorescence lifetime of the P3 assembly is about 2 ns.

Meso-tetraphenylporphyrin in liposomes as a suitable photosenzitizer for photodynamic therapy of tumors.

The suitability of a liposomal form of hydrophobic nonsulfonated meso-tetraphenyl porphyrin (TPP) for the photodynamic therapy of tumors was investigated. TPP was solubilized in small unilamellar lipid vesicles prepared by extrusion on a LIPOSOFAST apparatus. These samples were studied by laser-excited time resolved luminescence and triplet-triplet absorption spectroscopy. In this lipid environment TPP was still an efficient singlet oxygen producer, as indicated by the characteristic singlet oxygen phosphorescence at 1270 nm in D2O, when excited with a 28 ns laser pulse at 412 nm. Moreover, unlike with sulfonated TPP (TPPS4), liposomal TPP showed the reduced decay rates of TPP triplet-states with the increasing time of pre-illumination by a Xenon lamp. This was shown in an indirect way, based upon the appearance of a second component of the luminescence decay at 1270 nm in D2O; and by direct TPP triplet state monitoring, detecting triplet-triplet absorption at 440 nm in H2O. The deactivation of higher triplet states was delayed upon pre-illumination. This reflects an irreversible interaction of singlet oxygen with membrane lipids, thus demonstrating the potential of the liposomal form of TPP to efficiently disintegrate tumor cell membranes and to be a suitable preparation for the photodynamic therapy.

The effect of the irradiation wavelength on the processes sensitized by protoporphyrin IX dimethyl ester.

The formation of triplet states of photosensitizers and singlet oxygen during reactions sensitized by protoporphyrin IX dimethyl ester (PPDME) and the products of its photo-oxidation in solution were studied by time-resolved spectroscopy. Irradiation with long-wavelength light (670 nm), which is absorbed by the products of photo-oxidation of PPDME, provides lower quantum yields of singlet oxygen than in sensitization with PPDME alone, which absorbs light with a wavelength of 630 nm. Spectroscopic measurements also confirmed the lower rate of sensitized photo-oxidation of bilirubin during irradiation with light with a wavelength of 670 nm.

[Surgical treatment of anterior cruciate ligament.]. / Srovnání výsledku operacní a konzervativní lécby ruptury predního zkrízeného vazu.

The authors evaluate a group of 57 patients with rupture of the anterior cruciatee ligament (ACL). The first group is formed by 23 patients where the acute ACL rupture was treated by suture. The second group comprises 35 patients with a confirmed untreated complete ACL lesion. For comparison Lysholm's score was used; anteroposterior instability was assessed objectively by a KT apparatus. The authors investigated the range of movements of the knee joint. The mean value of Lysholm's score in the first group was 84 points, in the second group 80.7 points. The mean shift of the tibia in relation to the femur was 11.2 mm in patients after suture of the ligament and 12 mm in patients with an untreated ligament. In four patients of the first group a significantly restricted range of flexion of the knee joint persists. Based on these results and data in the literature the authors abondoned suture of the ACL and resolved instability in indicated cases by replacement of the ACL. Key words: anterior cruciate ligament, suture of ACL.

Bilirubin ditaurate--a sensitive compound for examination of photosensitizers.

Bilirubin ditaurate (taurobilirubin) proved to be very suitable for estimation of efficiency of different photosensitizers and for determination of the activity of singlet oxygen. The degree of its bleaching was measured at 450 nm, the excitation light was over 600 nm. Halogen lamps were used as light sources. The decoloration of bilirubin ditaurate was related to the intensity of the light source in the presence of the photosensitizer meso-tetra (4-sulfonatophenyl)-porphine (TPPS4). From photosensitizers conventionally used in photodynamic therapy (photosan 3, TPPS4, and Zn and Al chelates of phthalocyanine) chloroaluminium phthalocyanine was most effective. From synthetic dyes of nonporphyrin type thiazine dyes were most active. The presumption is expressed that the efficiency of noncoherent light is comparable to the laser radiation when photosensitizers with large absorption band 600-700 nm are used for photodynamic therapy.