Wyniki wyszukiwania - Biblioteka Nauki

1

Application of dynamic speckle methods to study thermal denaturation of the albumin

100%

Li X. , Tai Y. , Nie Z. , Chen Q. , Li L.

Optica Applicata

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2011

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tom Vol. 41, nr 3

581--591

EN

The process of the thermal denaturation of albumin was studied using dynamic speckle methods, which included the time history of speckle patterns (THSP), the THSP based on wavelet entropy (WE), speckle size measurement and the speckle pattern mean contrast techniques. In experiments, the dynamic speckle pattern sequences produced from the albumin colloid during heat denaturation were obtained using CCD camera. And then, using these dynamic speckle methods, the change of the movement properties of protein particles was analyzed during the heating process. All results show that the protein particles become bigger, their mean free path becomes shorter and the velocity of the Brownian movement becomes slower during the heating process. The experiments prove that dynamic speckle methods are useful tools to investigate the particles motion in solution.

2

The 30-day mortality predictor role of c-reactive protein/albumin ratio in critically ill COPD patients

100%

Cırık M. Ö. , Baldemir R. , Doğanay G. E. , Ünver M. , Avcı S.

Critical Care Innovations

|

2020

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tom 3

|

nr 4

1-12

XX

INTRODUCTION: Chronic Obstructive Pulmonary Disease (COPD) is a progressive disease that develops due to inflammation in the airways. The aim of this study is to demonstrate the effectiveness of c-reactive protein/albumin ratio (CAR) as a 30-day mortality indicator in COPD patients admitted to ICU. MATERIAL AND METHODS: A total of 235 COPD patients with available data between January 2018 and December 2018 were included in this retrospective cohort study. Demographics, APACHE II, Charlson comorbidity index (CCI), SOFA score, CAR and outcomes were evaluated. RESULTS: 87 (37%) of the cases were female and 148 (63%) were male. Their ages ranged from 26 to 95 years, with an average of 70.9± 11.4. The non-survivors had significantly higher APACHE II, CCI, SOFA score, procalcitonin, creatinine, mechanical ventilation (MV) time, WBC, CRP and CAR compared to the survivors (p˂0.05). Albumin and prealbumin were significantly lower (p˂0.05) in non-survivors. In the univariate model; age, sepsis, inotropic support, APACHE II score, CCI, SOFA, procalcitonin, creatinine, MV time, WBC, CRP, albumin, prealbumin and CAR were observed to be significantly effective (p˂0.05) in predicting 30-day mortality. In the multivariate reduced model; inotropic support, SOFA, WBC and prealbumin value exhibited significant independent (p<0.05) effectiveness in predicting 30-day mortality. Albumin, CRP, CAR, APACHE II, SOFA and CCI value were observed to be significant in predicting mortality (p=0.000). CONCLUSIONS: In the study, the predictive power of APACHE II score, CCI, SOFA score, albumin and prealbumin values alone was found to be significantly higher than that of the CAR.

3

Association of serum albumin and serum high-sensitivity C-reactive protein levels with acute ischemic stroke severity

100%

Choudhary M. , Kumar S. , Yadav R.

Critical Care Innovations

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2024

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tom 7

|

nr 3

25-34

EN

INTRODUCTION: Acute ischemic stroke, a type of cerebrovascular disease, is one of the most common causes of mortality and morbidity around the world. Albumin-induced neuroprotection can be attributed to properties such as reversal of thrombosis, improvement in microvascular blood perfusion, reduction in brain swelling. The increase in high-sensitivity C-reactive protein levels (hs-CRP) after an ischemic stroke suggests a systemic inflammatory response and reveals the degree of brain damage. The purpose of the study was to assess the association of serum albumin and serum high-sensitivity C-reactive protein levels with acute ischemic stroke severity. MATERIALS AND METHODS: Prospective cross-sectional observational study involving 90 patients admitted to the emergency department that met the inclusion and exclusion criteria. At the time of admission blood samples were taken for measurement of serum albumin level (normal albumin level ≥3.5 g/dl and hypoalbuminemia <3.5 g/dl), hs-CRP (low risk <1.0 mg/L; average risk 1.0-3.0 mg/L; high risk >3.0 mg/L). The severity of stroke was assessed using the National Institutes of health stroke scale (NIHSS) score. RESULTS: 60% of the cases had a normal albumin level, while 40% of the cases had hypoalbuminemia. 82.22% of the cases had a high risk level of hs-CRP, while only 1.11% of the cases had a low risk level of hs-CRP. The association of hypoalbuminemia and hs-CRP with stroke severity on the NIHSS score measured at the time of admission. It was observed that there was a statistically significant correlation between hypoalbuminemia with stroke severity (p-value <0.002) and between hs-CRP levels with stroke severity (p-value <0.013). CONCLUSIONS: The study concluded that the association between low serum albumin level and elevated hs-CRP levels with the severity of acute ischemic stroke was statistically significant.

PL

WSTĘP: Ostry udar niedokrwienny, rodzaj choroby naczyń mózgowych, jest jedną z najczęstszych przyczyn śmiertelności i zachorowalności na całym świecie. Neuroprotekcję wywołaną przez albuminę można przypisać takim właściwościom, jak odwrócenie zakrzepicy, poprawa mikronaczyniowego przepływu krwi, zmniejszenie obrzęku mózgu. Wzrost poziomów białka C-reaktywnego o wysokiej czułości (hs-CRP) po udarze niedokrwiennym sugeruje ogólnoustrojową odpowiedź zapalną i ujawnia stopień uszkodzenia mózgu. Celem badania była ocena związku stężenia albuminy w surowicy i stężenia białka C-reaktywnego o wysokiej czułości w surowicy z ciężkością ostrego udaru niedokrwiennego. MATERIAŁY I METODY: Prospektywne badanie obserwacyjne przekrojowe z udziałem 90 pacjentów przyjętych na oddział ratunkowy, którzy spełnili kryteria włączenia i wyłączenia. W momencie przyjęcia pobrano próbki krwi w celu zmierzenia poziomu albumin w surowicy (normalny poziom albumin ≥3,5 g/dl i hipoalbuminemia <3,5 g/dl), hs-CRP (niskie ryzyko <1,0 mg/l; średnie ryzyko 1,0-3,0 mg/l; wysokie ryzyko >3,0 mg/l). Ciężkość udaru oceniano za pomocą skali udaru National Institutes of Health (NIHSS). WYNIKI: 60% przypadków miało prawidłowy poziom albumin, podczas gdy 40% przypadków miało hipoalbuminemię. 82,22% przypadków miało wysoki poziom ryzyka hs-CRP, podczas gdy tylko 1,11% przypadków miało niski poziom ryzyka hs-CRP. Związek hipoalbuminemii i hs-CRP z ciężkością udaru w punktacji NIHSS mierzonej w momencie przyjęcia. Zaobserwowano, że istniała statystycznie istotna korelacja między hipoalbuminemią a ciężkością udaru (wartość p <0,002) i między poziomami hs-CRP a ciężkością udaru (wartość p <0,013). WNIOSKI: Badanie wykazało, że związek między niskim poziomem albuminy w surowicy i podwyższonym poziomem hs-CRP a ciężkością ostrego udaru niedokrwiennego był statystycznie istotny.

4

Interaction of anthracene and its oxidative derivatives with human serum albumin

100%

Skupińska K. , Zylm M. , Misiewicz I. , Kasprzycka-Guttman T.

Acta Biochimica Polonica

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2006

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tom 53

|

nr 1

101-112

EN

Binding affinities of ten polycyclic aromatic hydrocarbons to albumin were determined: anthracene, its eight oxy-derivatives: anthraquinone, 9-anthracenemethanol, 9-anthraldehyde, 9-anthracenecarboxylic acid, 1,4-dihydroxyanthraquinone, 1,5-dihydroxyanthraquinone, 1,8-dihydroxyanthraquinone, 2,6-dihydroxyanthraquinone and benzo[a]pyrene. The quenching of albumin fluorescence was used to measure the PAH - protein interaction. The theoretical curve of calculated fluorescence was fitted to experimental data after necessary corrections regarding PAHs fluorescence and inner filter effect. From the numerical fitting the final association constants were calculated. Anthracene and anthraquinone failed to quench the albumin fluorescence. 9-anthracenecarboxylic acid showed the highest, while 9-anthracenemethanol the weakest albumin binding affinity. The affinity constants determined for 9-anthraldehyde and benzo[a]pyrene were of the same magnitude and indicated low-affinity binding to albumin. The constants obtained for the four dihydroxyanthraquinones were higher, but dissimilar, which suggests that the position of the functional group in anthracene molecule influences the binding constant. Moreover, this study suggests that the type of substituent plays a significant role in PAH-albumin complex formation. The carboxylic group increases the binding affinity of the anthracene molecule the most rather than the presence of both carbonyl and hydroxyl groups. The lowest affinity constants were obtained for aldehyde, methyl and carbonyl substituents.

5

Predictive value of blood urea nitrogen to serum albumin ratio in estimating in-hospital mortality in patients with upper gastrointestinal bleeding

100%

Kurt E. , Eke Kurt S. Z.

European Journal of Clinical and Experimental Medicine

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2022

|

nr 3

342-347

EN

Introduction and aim. The aim of this study was to examine the usability of blood urea nitrogen to serum albumin ratio (BAR) as a prognostic predictor of in-hospital mortality in patients with gastrointestinal (GI) bleeding. Material and methods. The electronic medical records of the patients who applied to the emergency department due to upper GI bleeding during the study period were reviewed. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used to evaluate each discriminant cut-off value to estimate mortality. Results. The study included 225 patients. The median (IQR) age of the patients was 75.0 (68.0–84.0) and 94 (41.8%) were female. AUC was determined as 0.784±0.055 (95% CI, 0.677–0.892) for BAR (p<0.001) in terms of in-hospital mortality. The cut-off value of BAR for this outcome was calculated as 16.26. In this cut-off value, sensitivity was 71.43%, specificity 82.84%, positive predictive value (PPV) 30.00% and negative predictive value (NPV) 96.57%. Conclusion. BAR is a useful tool that can be used to predict the in-hospital mortality of patients with GI bleeding. Patients with GI bleeding with a BAR above 16.26 will require more aggressive and timely intervention.

6

Badania technologiczne trzech nagrobnych stel egipskich na podłożu drewnianym z Muzeum Narodowego w Krakowie : część I

88%

Szyszko W.

Ochrona Zabytków

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1972

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nr 3

170-182

EN

The a u th o r of th e p re s e n t a rtic le dev o ted his co n sid e ra tio n s to th e se t of th r e e E g y p tian e p ita p h ia l ste la e on wood su p p o rts a t p re s e n t being a p ro p e rty of th e C z a rto ry sk i Collection, N a tio n a l Museum, C ra cow. The ab o v e -m en tio n ed objects, up to th e p re s e n t day n o t published, a re ap p ro x im a te ly d a tin g from th e second millen ium B.C. w ith an ex c ep tio n of th e stele XI-645 which, according to ev e ry p ro b ab ility , is one much la te r. The a rtic le is composed of two p a rts. W ith in th e firs t of th em th e re su lts of in v e stig a tio n s a re p re sen ted , however, exclu d in g th e pigm en ts th e an a ly sis of which fo rms th e second p a r t of th is p u b lic a tio n . P re s en tin g th e s ta te of in v e stig a tio n s of Eg y p tian polychromies th e a u th o r tu rn s to an a ly sis of th e se p a ra te la y e rs on th e basis of s tra ty g ra p h ic e x am in a tio n s of objects. The re c e n t e x am in a tio n s h ave shown th a t th e ste la e were p roduced w ith th e use of A fric an mah ogany wood (Sapeli) which th e k in d of wood had not up to now b e en men tio n ed in Egyptologic lite r a tu re . By th e use of m ic ro -c ry sta llo g rap h ic m e th o d it has been found th a t all th e ob je c ts u n d e r co n sid e ra tio n were p a in te d on gypsum p rim e r co n sid e rab ly co n tam in a ted w ith m e ta lic adm ix tu re s. While te s tin g th e samples of p rim e r th e following m ethods w e re used: sp e c tro p h o tom e try in in f r a - r e d light, emission sp e c tro g rap h y , m ic ro -c ry s ta llo g ra p h y and th e p a p e r ch rom a to g rap h y to fin d th e tr a c e s of p ro te in m a tte rs. Samples of b in d e r p re s e n t in th e p a in te d la y e r w e re in v e stig a ted w ith th e use of b oth p a p e r and th in - la y e r ch rom ato g rap h y . The re su lts of ana ly se s p o in t to th e use of gum b in der, p ro b ab ly tra g a c a n th gum. In add itio n , th e a u th o r has ex am in ed th e side cuts ta k en from th re e ob je c ts and basing on X -ra y d iag ram s he g a th e red some d a ta re la tin g to th e s tru c tu re of support. No less in te re stin g p ro v ed to be th e re su lts of mycological in v e stig a tio n s c a rried o u t on th e su rfa c e s of stelae. Among those p re s e n t in ste la e some species of fu n g i w e re id en tified belonging to A sp e rg illu s and Pén ic illium fam ilie s and, besides, th e Clo ck er sp. y easts whose p re sen c e may prove d an g e ro u s fo r th e se u n u su a lly v a lu ab le objects. Within th e p re s e n t p u b lic a tio n th e emp h a sis h a s been laid u p o n th e d a ta re fe rrin g to in d iv id u a l p ro b lem s and a t th e same tim e th e d a ta coming from lite r a tu r e h av e been con fro n ted w ith re su lts of th e a u th o r ’s own investigations.

7

Light therapy for mechanical damages

88%

Olsztyńska S. , Dziamska A. , Komorowska M.

Acta of Bioengineering and Biomechanics

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1999

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tom Vol. 1, nr 1

129-133

EN

UV-VIS spectroscopy was used to study components of human tissue. Phenylalanie, dixydroxyphenylalanine, adenosine 5'-triphosphate and albumin all undergo changes under the influence of light and temperature. Characteristic bans for these materials were hightlighted and the relation to different solutions was compared. The role of UV-VIS spectroscopy for measuring tissue damages is discussed.

8

Quercetin influences BSA alpha-helical structures of native, ACR- and NaNO2-modified BSAs

75%

Rorbach-Dolata A. , Żurawska-Płaksej E. , Piwowar A.

Acta Poloniae Pharmaceutica - Drug Research

|

2018

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tom 75

|

nr 6

1339-1346

EN

Quercetin (QUE) is a plant flavonoid with a multifarious spectrum of properties. It is a prominent component of the human diet, considered to be safe and beneficial for human health. Acrylamide (ACR) and sodium nitrate III (NaNO2) are also present in the diet and may demonstrate adverse and toxic effects on the macromolecules and tissues of the human organism. Albumin, the most abundant blood protein, is the most susceptible to the action of various exogenous factors, which may lead to structural damage and functional disturbances. The aim of this study was to estimate ACR- and NaNO2-induced changes in the secondary structure of bovine serum albumin (BSA), using circular dichroism (CD), and to determine the impact of quercetin on these modifications. BSA was incubated with ACR and NaNO2 solutions in the absence and presence of QUE in two different concentrations (3 mM and 500 µM), and changes in albumin alpha-helical structure were determined by CD. BSA secondary structure was vulnerable to alterations upon treatment with acrylamide and NaNO2, as well as quercetin. QUE, depending on concentration and incubation time, caused a decrease of around 13-19% in the alpha-helix content of BSA molecules, but also prevented the changes in the protein alpha-helical structure initiated by ACR and NaNO2. The most spectacular inhibition was revealed for QUE in lower concentrations after 24h of incubation with NaNO2. Although QUE reveals protective effect towards albumin modifications, it is difficult to unambiguously define whether this effect is advantageous, because quercetin itself causes alterations in BSA structure.

9

Wieloskładnikowe układy chitozanowe jako żele termowrażliwe

75%

Modrzejewska Z. , Owczarz P. , Zarzycki R.

Inżynieria i Aparatura Chemiczna

|

2009

|

tom Nr 6

127-128

PL

W pracy przedstawiono badania nad żelami chitozanowymi formującymi się w fizjologicznej temperaturze ciała ludzkiego. Żele wytwarzano w oparciu o chlorek chitozanu i b-glicerofosforan sodu. W strukturę żelu wprowadzono albuminę, którą uwalniano do wody oraz buforu o pH = 10.

EN

Thermosensitive chitosan hydrogels - a subject of this study - might be carriers of new-generation. Investigations of the possible formation of thermogels based on chitosan chloride and sodium b-glyceropho-sphate with controlled release of albumin to water and to buffer at pH = 10 are described in the paper.

10

Post-exercise proteinuria in the cadets trained on Special Aerial Gymnastics Instruments

75%

Wochyński Z. , Sobiech K.

International Journal of Occupational Medicine and Environmental Health

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2015

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tom 28

|

nr 5

863-873

EN

Objectives Assessment of the effect of training on Special Aerial Gymnastics Instruments (SAGI) on the urine β-2- microglobulin (β-2M), albumin (ALB), total protein (TP), N-acetyl-β-D-glucosaminidase EC.3.2.1.30 (NAG), expressed as creatinine (Cr) and on the physical fitness of the examined cadets in comparison with the control group. Material and Methods The study involved 55 cadets aged 20, divided into group A (N = 41) trained on SAGI, and group B (N = 14) – a control group. The urine was collected twice: before the training (BT) and after the training (AT) at the start (training I), during (training II), and after completion of the training program (training III). Urine proteins were assayed with commercially available kits. Results In group A, results obtained in trainings I, II and III showed a statistically significant increase in β-2M/Cr, NAG/Cr, TP/Cr, ALB/Cr indices in AT compared with the baseline BT values. Similarly in group B, a statistically significant increase in β-2M/Cr, NAG/Cr (trainings I, II), TP/Cr, AT compared with the baseline BT values in trainings I, II, and III was noted. Comparison of both groups showed a higher value of the post-exercise proteinuria in group B than in group A. In group A, a significant correlation between TP/Cr vs. ALB/Cr, NAG/Cr vs. TP/Cr, β-2M/Cr vs. TP/Cr, i.e., r = 0.62 at p < 0.001; r = 0.33 at p = 0.03; r = 0.60 at p < 0.001, and r = 0.52 at p < 0.001, respectively, was observed in group A, training III, AT. Conclusions Assayed urine proteins depend on the intensity of physical exercise, the type of exercise, and the level of physical fitness.

11

Enhancing the stability of Haemonchus contortus glyceraldehyde-3-phosphate dehydrogenase and binding of host albumin to the parasite enzyme

75%

Nijo Y. , Mishra P. K. K. , Joshi P.

Acta Parasitologica

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2020

|

tom 65

|

nr 4

12

Changes of albumin secondary structure after palmitic acid binding : FT-IR spectroscopic study

75%

Oleszko A. , Hartwich J. , Gąsior-Głogowska M. , Olsztyńska-Janus S.

Acta of Bioengineering and Biomechanics

|

2018

|

tom Vol. 20, no. 1

59--64

EN

Purpose: Albumin is an universal transport protein. Plasma pool of free fatty acids arising from triglyceride hydrolysis, critical in energy metabolism and etiology of metabolic disorders is transported by albumin. According to various studies albumin has from seven to nine binding sites with diverse affinity to long chain fatty acids. X-ray diffraction crystallography measurements have provided data only for pure human serum albumin or albumin with fully saturated binding sites. These results have shown that amount of -helices is higher after fatty acids binding. Molecular mechanics simulations suggest that binding of fatty acids in two high-affinity sites leads to major conformational changes in albumin structure. The aim of this research was to investigate albumin secondary structure upon gradually increasing fatty acids to protein mole ratio. Methods: Fourier transform infrared spectroscopy was applied to study changes of bovine serum albumin (as an analogue of human serum albumin) -helical structures after binding palmitic acid in a range of 0–20 palmitic acid: albumin molar ratios representing pure protein, partial, full saturation and excess binding sites capacity. Results: Amount of -helices was increasing along with the amount of palmitic acid: bovine serum albumin molar ratio and reached maximum value around 2 mol/mol. Conclusions: Our studies confirmed molecular mechanics simulations and crystallographic studies. Palmitic acid binding in two high-affinity sites leads to major structural changes, filling another sites only slightly influenced bovine serum albumin secondary structure. The systematic study of fatty acids and albumin interactions, using an experimental model mimicking metabolic disorders, may results in new tools for personalized nanopharmacotherapy.

13

The estimation of enzymatic digestibility of albumin proteins from wheat grain exposed to gamma irradiation 60 Co

75%

Warchalewski J. R. , Gralik J. , Kusnierz R.

Food Science and Technology. Scientific Papers of Agricultural University of Poznan

|

1998

|

tom 02

14

Paraffin oil particles as microscopic probes for oxygen measurements in biological systems: ESR spin-label oximetry

75%

Ligeza A. , Wisniewska A. , Subczynski W. K.

Current Topics in Biophysics

|

1992

|

tom 16

|

nr 2

15

A one-step in vitro continuous flow assessment of protein release from core-shell polymer microcapsules designed for therapeutic protein delivery

63%

Kupikowska-Stobba B. , Grzeczkowicz M. , Lewińska D.

Biocybernetics and Biomedical Engineering

|

2021

|

tom Vol. 41, no. 4

1347--1364

EN

Developing accurate methods for the assessment of therapeutic protein release from polymer drug delivery systems (microcapsules, microspheres, nanoparticles, 3D-printed systems) is of paramount importance for new formulation development. The most straightforward method for protein release assessment is spectrophotometric analysis of the release medium surrounding the formulation. However, direct spectrophotometric analysis is inapplicable to formulations releasing interfering compounds (coencapsulated drugs, additives) absorbing light in the same spectrum as proteins. Conventional protein release assays also require frequent release medium sampling and replacement, which reduces their accuracy. We propose a one-step method to assess protein release from core/shell microcapsules eliminating the need for sampling and allowing selective real-time protein quantitation in the release medium. To prevent spectral interferences, released protein is differentiated from interfering compounds by employing a colorimetric protein assay reagent, forming a colour complex selectively with the protein, as the release medium. To eliminate sampling, we employed a continuous flow closed loop set-up, where the release medium is constantly circulating between microcapsule-containing tank and spectrophotometer. A series of colorimetric protein assay reagents (bromocresol green, tetrabromophenol blue, eosin B, eosin Y, biuret) were evaluated in terms of their applicability as the release medium in described system. Only biuret reagent was found compatible with proposed method due to formation of color complex stable over extended period of time and low adsorption to microcapsules. Presented method allowed effective evaluation of albumin release from alginate-polyethersulfone microcapsules with accuracy equal to conventional ‘sample and separate’ technique. Albumin release followed first-order kinetics with plateau reached after 19 h.

16

Albuminy mleka - właściwości fizykochemiczne i funkcje biologiczne

63%

Brodziak A. , Litwińczuk Z. , Król J.

Przemysł Spożywczy

|

2013

|

tom T. 67, nr 10

32--34

PL

Białka mleka wpływają na jego wartość odżywczą, prozdrowotną i przydatność technologiczną. W artykule przedstawiono właściwości fizykochemiczne i funkcje biologiczne głównych białek serwatkowych, tj. β-laktoglobuliny, α-laktoalbuminy i albuminy serum. Współczesne doniesienia o udowodnionym lub potencjalnym, wielokierunkowym, pozytywnym oddziaływaniu tych składników na organizm człowieka wpływają na podniesienie świadomości konsumenckiej, co ma wpływ na wzrost spożycia przetworów mlecznych przez osoby dbające o swoje zdrowie. Należy jednak pamiętać, że zawartość prozdrowotnych albumin w produktach mlecznych zależy w dużym stopniu od przetworzenia mleka.

EN

Milk proteins determine its nutritional and health-promoting value as well as technological suitability. This paper presents the physicochemical properties and biological functions of major whey proteins, i.e. β-lactoglobulin, α-lactoalbumin and serum albumin. Contemporary reports of proven or potential, multidirectional and positive effects of these compounds on the human body impact on raising consumer’s awareness; consequently, the consumption of the dairy products for people who want to take care of their health is increased. However, it should be noted that the content of health-promoting albumins in the dairy products is significantly affected by the degree of milk processing.

17

Serum protein fractions in piglets – comparison of two types of agarose carriers

63%

Silecka A. , Fijalkowski K. , Czernomysy-Furowicz D.

Advances in Agricultural Sciences

|

2011

|

tom 14

|

nr 1-2

18

Construction of a bilirubin biosensor based on an albumin-immobilized quartz crystal microbalance

63%

Kocakulak M. , Bayrak T. , Saglam S.

Biocybernetics and Biomedical Engineering

|

2017

|

tom Vol. 37, no. 3

611--617

EN

Bilirubin, a bile pigment, is associated with several diseases and systemic pathologies. The measurement of bilirubin is important for diagnosis and therapy, and many expensive methods are used to measure the bilirubin amount in blood. In this study, a new bilirubin biosensor using quartz crystal microbalances immobilized with albumin is proposed. To measure the effectiveness of the biosensor, a series of experiments was realized with various concentrations of bilirubin, including 1 mg/dL, 2 mg/dL, 5 mg/dL and 10 mg/dL. Comparing blood gas analyzers, laboratory analyzers, skin test devices and nonchemical photometric devices, blood gas analyzers have a range of 0.5–35 mg/dL, laboratory analyzers have a range of 0–30 mg/dL, skin test devices could be used up to 11.7 mg/dL, and nonchemical photometric devices could be evaluated as reliable up to 14.6 mg/dL. The low limit range of the bilirubin detection is between 0.099 mg/dL and 0.146 mg/dL for some special commercial bilirubin measurement devices. Nevertheless, this study presents measurements with a high sensitivity and includes the advantage of reusability by using cheaper materials. To prove albumin immobilization and the bilirubin–albumin interaction atomic force microscopy (AFM) was used, and a good correlation was achieved from AFM images. In conclusion, considering the cost-effectiveness side of the proposed method, a low cost and more sensitive bilirubin measurement device which is effective and reusable was developed instead of the current commercial products.

19

Proteolytic activity of Bacillus cereus strains

63%

Nabrdalik M. , Grata K. , Latała A.

Proceedings of ECOpole

|

2010

|

tom Vol. 4, No. 2

273--277

EN

The aim of conducted research was to assess proteolytic activity of Bacillus cereus strains, depending on the source of proteins in a growth medium and temperature. Two Bacillus cereus strains: G10 and A96, isolated from soil and water respectively, were applied in the research. The source of carbon in the growth media was provided by the protein substrates as follows: albumin, casein and skimmed milk. The temperature ranged between 30 and 60ºC. The proteolytic activity was determined with the use of a spectrophotometric method with 2% casein as a substrate, at the wavelength λ = 560 nm. In the experiment, the proteolytic activity depended on the type of protein substrate in the growth medium and the temperature. B. cereus G10 strain showed the highest activity at 30ºC in case of albumin and the lowest in the growth medium with skimmed milk. At temperatures 40 and 50ºC the most favourable medium was with an addition of skimmed milk and the least favourable with albumin. Proteolytic activity was not recorded when the temperature was the highest and the medium contained skimmed milk, whereas at the same temperature the lowest activity was noted again in the medium with albumin. Bacillus cereus A96 strain showed, however, different activity. The highest activity was noted at tempertaures of 30 and 50ºC in the medium with skimmed milk, and the lowest in the medium with casein. The opposite was noted at 40ºC, as no proteolytic activity was recorded in the presence of skimmed milk while the highest was recorded in the presence of casein. When analysing the influence of the temperature on the proteolytic activity, it has been noted that strains of Bacillus cereus are the most vigorous at the temperature of 30 and 40ºC, and the least vigorous at 50 and 60ºC. The highest recorded values for the screened strains have been obtained at 30 and 40ºC in the medium with skimmed milk.

PL

Celem podjętych badań była ocena aktywności proteolitycznej szczepów Bacillus cereus w zależności od źródła białka zawartego w podłożu oraz temperatury. Do badań wykorzystano 2 szczepy Bacillus cereus G10 oraz A96 wyizolowane odpowiednio z gleby i wody. Źródłem węgla w pożywkach były substraty białkowe: albumina, kazeina oraz odtłuszczone mleko. Aktywność proteolityczną oznaczono w zakresie temperatur od 30 do 60ºC. Oznaczenia aktywności proteolitycznej przeprowadzono metodą spektrofotometryczną, używając jako substratu 2% kazeiny po 10-minutowej inkubacji, przy długości fali λ = 560 nm. W przeprowadzonym doświadczeniu aktywność proteolityczna uzależniona była od rodzaju substancji białkowej zawartej w podłożu oraz temperatury. I tak, badany szczep B. cereus G10 w temperaturze 30ºC największą aktywność proteolityczną wykazywał w obecności albuminy, a najniższą w obecności odtłuszczonego mleka. W temperaturach 40 i 50ºC najkorzystniejszym podłożem okazało się podłoże zawierające odtłuszczone mleko, a najmniej korzystne zawierające albuminę. W najwyższej temperaturze nie stwierdzono aktywności proteolitycznej w obecności odtłuszczonego mleka, zaś najniższą aktywność odnotowano ponownie w środowisku albuminy. Z kolei drugi z badanych szczepów, Bacillus cereus A96, charakteryzował się odmienną aktywnością. W temperaturach 30 i 50ºC najwyższą aktywność proteolityczną odnotowano w podłożu zawierającym odtłuszczone mleko, a najniższą w środowisku kazeiny. Natomiast w temperaturze 40ºC zaobserwowano odwrotną sytuację, gdyż nie stwierdzono aktywności proteolitycznej w obecności odtłuszczonego mleka, a najwyższą aktywność uzyskano w obecności kazeiny. Analizując wpływ temperatury na aktywność proteolityczną, stwierdzono, iż największą aktywność badane szczepy Bacillus cereus wykazują w temperaturach 30 i 40ºC, a najmniejszą w 50 i 60ºC. Najwyższe wartości dla badanych szczepów uzyskano w temperaturach 30 i 40ºC na podłożu z dodatkiem odtłuszczonego mleka.

20

Glin i albumina

63%

Kopyść E. , Bulska E. , Szafrańska K.

Analityka : nauka i praktyka

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2003

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tom nr 1

36--38