Enzyme immobilization by adsorption : a review

Endowed with unparalleled high catalytic activity and selectivity, enzymes offer enormous potential as catalysts in practical applications. These applications, however, are seriously hampered by enzymes’ low thermal and chemical stabilities. One way to improve these stabilities is the enzyme immobilization. Among various tested methods of this process that make use of different enzyme-carrier interactions, immobilization by adsorption on solid carriers has appeared most common. According to these findings, in this review we present a comparative analysis of the literature reports on the recent trends in the immobilization of the enzymes by adsorption. This thorough study was prepared in order to provide a deeper understanding of the process. Both carriers, carrier modifiers and procedures developed for effective adsorption of the enzymes are discussed. The review may thus be helpful in choosing the right adsorption scheme for a given enzyme to achieve the improvement of its stability and activity for a specific application

Cele polityki ekologicznej Polski i Unii Europejskiej z uwzględnieniem gospodarki leśnej

The article contains an analysis of the primary terms and notions such as politics. Ecological politics, ecology, forest management, and basic information concerning the ecological policy in Poland and in the European Union

Temperature- and pressure-dependent stopped-flow kinetic studies of jack bean urease : implications for the catalytic mechanism

Urease, a Ni-containing metalloenzyme, fea- tures an activity that has profound medical and agricultural implications. The mechanism of this activity, however, has not been as yet thoroughly established. Accordingly, to improve its understanding, in this study we analyzed the steady-state kinetic parameters of the enzyme (jack bean), K M and k cat , measured at different temperatures and pres- sures. Such an analysis is useful as it provides information on the molecular nature of the intermediate and transition states of the catalytic reaction. We measured the parame- ters in a noninteracting buffer using a stopped-flow tech- nique in the temperature range 15–35 ° C and in the pressure range 5–132 MPa, the pressure-dependent mea- surements being the first of their kind performed for urease. While temperature enhanced the activity of urease, pres- sure inhibited the enzyme; the inhibition was biphasic. Analyzing K M provided the characteristics of the formation of the ES complex, and analyzing k cat , the characteristics of the activation of ES. From the temperature-dependent measurements, the energetic parameters were derived, i.e. thermodynamic D H o and D S o for ES formation, and kinetic D H = and D S = for ES activation, while from the pressure- dependent measurements, the binding D V b and activation D V 6 ¼ cat volumes were determined. The thermodynamic and activation parameters obtained are discussed in terms of the current proposals for the mechanism of the urease reaction, and they are found to support the mechanism proposed by Benini et al. ( Structure 7:205–216; 1999), in which the Ni–Ni bridging hydroxide—not the terminal hydroxide—is the nucleophile in the catalytic reaction

The morphological evaluation of the homograft wall in an electron microscopic study

Cases of massive purulent infection of vascular prosthesis are demonstrated in this study. Infected prosthesis was substituted by arterial homograft, harvested during multi-organ procurement, and stored by the cold ischaemia method. In the follow-up period, the patients were divided into two groups, those treated with immunosuppression (n = 16) and those treated without immunosuppressive drugs (n = 13). The patients underwent resurgery, during which a fragment of arterial wall was taken for electron microscopic examination. In the group with immunosuppression, the presence of the following structures was observed: endothelial cells, the intima, with a great number of elastic and collagen fibrils with fibrinogen inclusions, and active phagocyting myoblasts and myofibroblasts. In the group without immunosuppression electron microscopic examination showed the total destruction of the wall of the ruptured arterial homograft - absence of endothelium and sparse, damaged fibroblasts of the media or their degraded fragments, making a picture of cellular death. Morphological analysis of the arterial wall and the clinical state of the patient suggest the necessity of immunosuppressive treatment after fresh arterial homograft transplantation

Analiza kliniczna wydalania jodu z moczem u chorych na zróżnicowane raki tarczycy w trakcie terapii L-tyroksyną

Introduction: Urinary iodine concentrations were analyzed in the morning urine samples of patients with differentiated thyroid cancer (DTC). Material and methods: The analyzed group included 572 DTC patients who were treated with radioiodine or hospitalized for evaluation of radioiodine treatment effects in 2009 at the Institute of Oncology in Gliwice. Ioduria was analyzed by PAMM (Program Against Micronutrient Malnutrition) method before rhTSH administration. A total of 545 tests were performed during L-thyroxine treatment and 27 after L-thyroxine withdrawal. Results: Median L-thyroxine dose was 150 &#956;g/day. Median ioduria was 127.5 &#956;g/L during L-thyroxine therapy and 134 &#956;g/L after the L-thyroxine withdrawal. No distinct relation between ioduria and L-thyroxine dose was observed. Ioduria < 200 &#956;g/L was observed in over 90% of patients and this cut-off was chosen for the reference range. Only 1.2% of patients showed a distinct stable iodine contamination (ioduria &#8805; 300 &#956;g/L). Conclusions: Urinary iodine concentrations in differentiated thyroid cancer patients treated with L-thyroxine vary in a wide range and do not show a clear relation with L-thyroxine dose. (Pol J Endocrinol 2010; 61 (5): 458-461)Wstęp: W pracy przeanalizowano stężenie jodu w porannej próbce moczu u chorych na zróżnicowanego raka tarczycy (DTC, differentiated thyroid cancer). Materiały i metody: Badano 572 chorych na DTC po operacji, którzy w 2009 roku byli hospitalizowani w celu leczenia jodem radioaktywnym lub oceny jego wyników. Stężenie jodu w moczu oznaczano metodą PAMM (Program Against Micronutrient Malnutrition). W trakcie leczenia L-tyroksyną wykonano 545 badań, 27 po przerwie w stosowaniu L-tyroksyny. Wyniki: Mediana dawki L-tyroksyny wynosiła 150 &#956;g/dzień. Mediana dobowego wydalania jodu z moczem wynosiła 127,5 &#956;g/L, a po odstawieniu L-tyroksyny 134 &#956;g/L. Nie obserwowano zależności stężenia jodu w moczu od stosowanej dawki tyroksyny. Jodurię < 200 &#956;g/L obserwowano u ponad 90% chorych i ten zakres uznano za referencyjny. Kontaminację stabilnym jodem wykazano u 1,2% (joduria &#8805; 300 &#956;g/L). Wnioski: Stężenia jodu w moczu u chorych na zróżnicowanego raka tarczycy, leczonych L-tyroksyną, wahają się w szerokim przedziale wartości i nie korelują z dawką L-tyroksyny. (Endokrynol Pol 2010; 61 (5): 458-461

Median nerve conduction impairment in patients with diabetes and its impact on patients’ perception of health condition: a quantitative study

INTRODUCTION: Impaired mobility and compromised manual dexterity leading to difficulties with the activities of daily living (ADL) are an inherent part of the clinical picture in diabetes. Hand function in diabetes is influenced by a variety of pathologies: the median nerve, the most important nerve of the hand, can suffer from metabolic disturbances, ischemia and/or entrapment neuropathies. The resulting deterioration in functional capacity is likely to have significant consequences for the ability to perform ADL, influencing adjustment to diabetes and affecting quality of life. The aim of the present study was to examine the influence of hand function as measured by median motor nerve conduction on quality of life, taking into account various aspects of functioning in patients with diabetes, including activities of daily living, psychological status and acceptance of illness. PATIENTS AND METHODS: Seventy one hospital patients with diabetes participated in the study. Electrophysiological recordings of conductance in the median nerve were obtained for both hands and the relationship between hand function and functional status (BI), depression and anxiety (HADS), adjustment to illness (AIS) and their effect on quality of life (SF-36v2 and QLI) was studied. RESULTS: Damage to the median nerve of the left hand was associated with significant differences in functioning in the physical, but not the mental component of the SF-36v2, p = 0.03 and in functional status (p = 0.006). QOL was associated with depression, patient age, acceptance of illness, functional ability and to a small, but significant extent with median nerve damage to the right hand on the measure of conduction velocities (R2 =0.726). CONCLUSIONS: Nerve conductance studies demonstrated a small, but significant effect of hand function on quality of life. Impairment of the median nerve in the left hand was associated with functional difficulties in the activities of daily living and a diminished quality of life in the area of physical functioning. No dependencies of this kind were found for the right hand, which may reflect the greater compensatory capacity of the right hand resulting from improved efficiency due to practice

Leczenie sorafenibem w zaawansowanym raku tarczycy - opis przypadku

Papillary thyroid cancer (PTC) usually has a good prognosis. The treatment, including total thyroidectomy and complementary radioiodine (RAI) therapy, gives complete remission in 90% of patients. However, in 10% of subjects with metastatic disease, the prognosis is poor. In the group of patients with disease progression and no 131I uptake, searching for new therapeutic modalities before all tyrosine kinase inhibitors and other antiangiogenic agents is necessary. The study presents the case of a 55-year-old male with advanced PTC /pT3mNxMo/ diagnosed in 1993. Primary treatment by total thyroidectomy and 131I ablation led to complete remission. In 2000 local as well as lymph node recurrence was diagnosed and successively treated by surgery. In 2006 an increasing serum thyroglobulin level was noted and a single lung metastasis was diagnosed and operated on. In 2007 new foci in CNS and vertebral column with no 131I uptake were stated. Further progression (bones, CNS, and pterygoid muscle) was confirmed by PET-CT. The patient underwent neurosurgical metastasectomy twice and palliative CNS and vertebra&#8217;s radiotherapy. Liver metastases were diagnosed in 2009. Treatment with increasing doses of thalidomide (up to 800 mg/d) was administered for 3 months with a good tolerance; however, the therapy was withdrawn due to cancer progression. Next, sorafenib (800 mg/d) was given for 16 weeks. Radiological examination performed after 16 weeks confirmed stable disease, whereas 2 months later, after sorafenib withdrawal due to lack of treatment possibility, further progression was observed. Metronomic chemotherapy with Adriamycin was instituted which gave disease stabilization for 6 months. The patient died with advanced disseminated disease due to pulmonary embolism. We present this case to document no adverse effects of therapy with sorafenib in a patient with brain DTC metastases. Sorafenib therapy was only short-term, but no progression occurred in this time. (Pol J Endocrinol 2010; 61 (5): 492-496)Rak brodawkowaty tarczycy należy do nowotworów o dobrym rokowaniu. Terapia oparta na całkowitym wycięciu tarczycy i uzupełniającym leczeniu jodem promieniotwórczym u 90% pacjentów prowadzi do całkowitej remisji choroby nowotworowej. U około 10% chorych, u których dochodzi do rozsiewu raka, rokowanie jest niepomyślne. U chorych, z rozsiewem raka, u których ogniska nowotworu nie wykazują zdolności wychwytu 131I konieczne jest poszukiwanie nowych możliwości terapeutycznych. W tym kontekście rozważa się zastosowanie leków antyangiogennych, w tym inhibitorów kinaz tyrozynowych. W pracy przedstawiono przypadek 55-letniego pacjenta z rozpoznaniem zaawansowanego raka brodawkowatego tarczycy/pT3mNxMo leczonego od 1993 roku, u którego w terapii zastosowano inhibitor angiogenezy (talidomid) i kinaz tyrozynowych (sorafenib). Leczenie pierwotne, dwuetapowe całkowite wycięcie tarczycy w 1994 i uzupełniające leczenie 131I (60 mCi) w 1994 roku doprowadziło do remisji choroby nowotworowej. W 2000 chory przebył operacyjne usunięcie wznowy miejscowej i przerzutów do węzłów chłonnych. W 2006 roku, w toku diagnostyki narastającej hipertyreoglobulinemii rozpoznano przerzut do płuca prawego, który usunięto operacyjnie. W 2007 roku stwierdzono niejodochwytny przerzut do kręgosłupa i ośrodkowego układu nerwowego (OUN). Kontrolne badania obrazowe, w tym PET-CT, potwierdziły dalszą progresję raka pod postacią nowych ognisk przerzutowych w OUN, kośćcu i mięśniu skrzydłowym. Chory przebył 2-krotne operacyjne usunięcie zmian ogniskowych w OUN, paliatywną radioterapię OUN i paliatywną radioterapię przerzutu do kręgosłupa. W 2009 roku rozpoznano przerzuty do wątroby. W dalszej terapii stosowano talidomid we wzrastającej dawce do 800 mg/d. przez okres 3 miesięcy, co nie zapobiegło dalszej progresji. Następnie chory otrzymywał sorafenib w dawce 800 mg/d. przez okres 16 tygodni. Badania obrazowe wykonane po 16 tygodniach terapii potwierdziły stabilizację choroby nowotworowej, natomiast 2 miesiące po odstawieniu leku ze względu na brak możliwości kontynuacji terapii doszło do dalszej progresji. Następnie chory otrzymywał przez okres 6 miesięcy metronomiczną chemioterapię (adriblastyna), która doprowadziła do stabilizacji choroby. Chory zmarł w stadium zaawansowanego raka tarczycy z powodu zatorowości płucnej. Wniosek: W prezentowanym przypadku chorego na raka brodawkowatego tarczycy z przerzutami do mózgu, terapia sorafenibem nie spowodowała żadnych powikłań, a w czasie 16 tygodni jej stosowania obserwowano stabilizację zaawansowanej choroby nowotworowej. (Endokrynol Pol 2010; 61 (5): 492-496