Thermal and morphological properties of human erythrocytes from patients afflicted with type 1 diabetes mellitus.

Red blood cells (RBC), are the most unique and abundant cell types. The diameter of RBCs is 7-8 μm. They have an essential role in transporting circulatory oxygen.

Exploring the Role of Neuropeptide PACAP in Cytoskeletal Function Using Spectroscopic Methods.

The behavior and presence of actin-regulating proteins are characteristic of various clinical diseases. Changes in these proteins significantly impact the cytoskeletal and regenerative processes underlying pathological changes. Pituitary adenylate cyclase-activating polypeptide (PACAP), a cytoprotective neuropeptide abundant in the nervous system and endocrine organs, plays a key role in neuron differentiation and migration by influencing actin.

Thermodynamic Sensitivity of Blood Plasma Components in Patients Afflicted with Skin, Breast and Pancreatic Forms of Cancer.

According to the World Health Organization's 2018 Global Cancer Survey, cancer is the second leading cause of death. From this survey, the third most common is breast cancer, the fifth is melanoma malignum and pancreatic adenocarcinoma ranks twentieth. Undoubtedly, the early diagnosis and monitoring of these tumors and related research is important for aspects of patient care.

Efficacy of microbiological culturing in the diagnostics of joint and periprosthetic infections.

Objectives: To evaluate the efficacy of conventional microbiological examinations in the diagnostics of septic joint and periprosthetic inflammations.

Design And Setting: Evidence Level IV, retrospective clinical study of case series. Patients treated with small and large joint septic inflammations or with periprosthetic joint infections (PJI) were entered into the study.

Spectroscopic characterization of the effect of mouse twinfilin-1 on actin filaments at different pH values.

The effect of mammalian twinfilin-1 on the structure and dynamics of actin filaments were studied with steady state fluorescence spectroscopy, total internal reflection fluorescence microscopy and differential scanning calorimetry techniques. It was proved before that the eukaryotic budding yeast twinfilin-1 can efficiently bind and severe actin filaments in vitro at low pH values. In the present work steady-state anisotropy measurements revealed that twinfilin can bind efficiently to F-actin.

The effect of toxofilin on the structure and dynamics of monomeric actin.

The effects of toxofilin (an actin binding protein of Toxoplasma gondii) on G-actin was studied with spectroscopy techniques. Fluorescence anisotropy measurements proved that G-actin and toxofilin interact with 2:1 stoichiometry. The affinity of toxofilin to actin was also determined with a fluorescence anisotropy assay.

EFFECT OF PHALLOIDIN ON FILAMENTS POLYMERIZED FROM HEART MUSCLE ADP-ACTIN MONOMERS.

The effect of phalloidin on filaments polymerized from ADP-actin monomers of the heart muscle was investigated with differential scanning calorimetry. Heart muscle contains alpha-skeletal and alpha-cardiac actin isoforms. In the absence of phalloidin the melting temperature was 55 degrees C for the alpha-cardiac actin isoform and 58 degrees C for the alpha-skeletal one when the filaments were generated from ADP-actin monomers.

Noncooperative stabilization effect of phalloidin on ADP.BeFx- and ADP.AlF4-actin filaments.

Actin plays important roles in eukaryotic cell motility. During actin polymerization, the actin-bound ATP is hydrolyzed to ADP and P i. We carried out differential scanning calorimetry experiments to characterize the cooperativity of the stabilizing effect of phalloidin on actin filaments in their ADP.

Nucleotide dependent differences between the alpha-skeletal and alpha-cardiac actin isoforms.

The thermodynamic properties of the actin filaments prepared from cardiomyocytes were investigated with differential scanning calorimetry. This method could distinguish between the alpha-cardiac and alpha-skeletal components of the actin filaments polymerised from ADP-actin monomers by their different melting temperatures (T(m)). Similar separation was not possible with filaments polymerised from ATP-actin monomers.

The effect of jasplakinolide on the thermodynamic properties of ADP.BeF(x) bound actin filaments.

The effect of BeF(x) and a natural toxin (jasplakinolide) was examined on the thermal stability of actin filaments by using differential scanning calorimetry. The phosphate analogue beryllium fluoride shifted the melting temperature of actin filaments (67.4 degrees C) to 83.

Differential scanning calorimetry study of glycerinated rabbit psoas muscle fibres in intermediate state of ATP hydrolysis.

Background: Thermal denaturation experiments were extended to study the thermal behaviour of the main motor proteins (actin and myosin) in their native environment in striated muscle fibres. The interaction of actin with myosin in the highly organized muscle structure is affected by internal forces; therefore their altered conformation and interaction may differ from those obtained in solution. The energetics of long functioning intermediate states of ATP hydrolysis cycle was studied in muscle fibres by differential scanning calorimetry (DSC).

Formins regulate actin filament flexibility through long range allosteric interactions.

The members of the formin family nucleate actin polymerization and play essential roles in the regulation of the actin cytoskeleton during a wide range of cellular and developmental processes. In the present work, we describe the effects of mDia1-FH2 on the conformation of actin filaments by using a temperature-dependent fluorescence resonance energy transfer method. Our results revealed that actin filaments were more flexible in the presence than in the absence of formin.

A simple model for the cooperative stabilisation of actin filaments by phalloidin and jasplakinolide.

The stabilisation of magnesium actin filaments by phalloidin and jasplakinolide was studied using the method of differential scanning calorimetry. The results showed that actin could adapt three conformations in the presence of drugs. One conformation was adapted in direct interaction with the drug, while another conformation was identical to that observed in the absence of drugs.

The effect of phalloidin and jasplakinolide on the flexibility and thermal stability of actin filaments.

In this work the effect of phalloidin and jasplakinolide on the dynamic properties and thermal stability of actin filaments was studied. Temperature dependent fluorescence resonance energy transfer measurements showed that filaments of Ca-actin became more rigid in the presence of phalloidin or jasplakinolide. Differential scanning calorimetric data implied that the stiffer filaments also had greater thermal stability in the presence of phalloidin or jasplakinolide.

Effect of polycyclic aromatic hydrocarbons on erythrocyte membranes by DSC and EPR.

Differential scanning calorimetry (DSC) and electron paramagnetic resonance spectroscopy (EPR) experiments were performed on human erythrocyte membranes and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) model systems in order to study the effect the polycyclic aromatic hydrocarbons on lipid structure and dynamics. Eight different compounds among others naphthalene and pyrene were compared, which occur in significant concentrations in dust collected from the air in large cities. Experiments using spin label technique showed that the compounds induced mobility changes in the lipid region in the environment of the fatty acid probe molecules incorporated into the membranes.

Analysis of nucleotide myosin complexes in skeletal muscle fibres by DSC and EPR.

The internal dynamics and thermal unfolding of fibre bundles prepared from rabbit psoas muscle has been studied in the presence of nucleotides by differential scanning calorimetry (DSC) and electron paramagnetic resonance (EPR) spectroscopy. Using ADP, adenosine 5'-triphosphate (ATP), AMP.PNP and inorganic phosphate analogue orthovanadate (V(i)), AlF(4)(-) and BeF(3)(-), three intermediate states of the ATP hydrolysis cycle were simulated in glycerinated muscle fibres.

Effect of nucleotides and their analogues on essential light chains in myosin head.

The domain movement in myosin head plays a decisive role in the energy transduction process of the muscle contraction. During hydrolysis of ATP, the specific formation of strong binding of myosin head for actin causes conformational changes. As a consequence, the light chain-binding motif generates the powerstroke.

Effect of adenosine 5'-[beta,gamma-imido]triphosphate on myosin head domain movements.

Conventional and saturation transfer electron paramagnetic resonance spectroscopy (EPR and ST EPR) was used to study the orientation of probe molecules in muscle fibers in different intermediate states of the ATP hydrolysis cycle. A separate procedure was used to obtain ST EPR spectra with precise phase settings even in the case of samples with low spectral intensity. Fibers prepared from rabbit psoas muscle were labeled with isothiocyanate spin labels at the reactive thiol sites of the catalytic domain of myosin.

Nucleotide binding induces global and local structural changes of myosin head in muscle fibres.

Thermal stability and internal dynamics of myosin heads in fiber bundles from rabbit psoas muscle has been studied by electron paramagnetic resonance (EPR) spectroscopy and differential scanning calorimetry (DSC). Using ADP, ATP and orthovanadate (V(i)), three intermediate states of the ATP hydrolysis cycle were simulated in glycerinated muscle fibers. DSC transitions contained three overlapping endotherms in each state.

Effect of oxygen free radicals on myosin in muscle fibres.

Experiments were performed on glycerol-extracted muscle fibres prepared from psoas muscle of rabbit in the presence of hydroxyl free radical generating system. Short irradiation of spin-labelled muscle fibres by UV light showed the interaction of probe molecules with oxygen free radicals. The intensity of the EPR signal from maleimide or isothiocyanate spin labels attached to the essential thiol groups decreased following irradiation.

Internal motions in myosin head: effect of ADP and ATP.

Internal flexibility of myosin heads in glycerinated muscle fibres in the presence of MgADP plus orthovanadate and after addition of Ca-ATP was studied using an isothiocyanate-based spin label attached to the reactive sulfhydryl sites of myosin. The spin labels were immobilized on the microsecond time scale and exhibited significant orientational order in rigor. In AM+.

Effects of nucleotide on skeletal muscle myosin unfolding in myofibrils by DSC.

The thermal unfolding of myosin in skeletal muscle myofibrils was studied by differential scanning calorimetry (DSC). In the absence of nucleotide two major transitions with Tm of 52 degrees C and 58 degrees C, and a minor transition with Tm of 19 degrees C were detected. The unfolding can be characterized with a total enthalpy of -90 +/- 6.

Segmental flexibility of cardiac myosins.

Conventional and saturation transfer electron paramagnetic resonance spectroscopy (EPR and ST EPR) and differential scanning calorimetry (DSC) were used to study the motional dynamics and structural stability of cardiac myosins. Cardiac myosins isolated from bovine and human heart muscle were spin-labelled with a maleimide- or an iodoacetamide-based probe molecule at the reactive sulhydryl sites (Cys-697 and Cys-707). The probe molecules rotated with an effective rotational correlation time of 0.

Spontaneous rupture of the kidney: a report on 5 cases.

Five cases of spontaneous rupture of the renal parenchyma are reported. Two patients had renal cell cancer, one sustained acute purulent pyelonephritis secondary to stone related ureteral obstruction, one suffered from aposthematous pyelonephritis without obstruction, while one had chronic pyelonephritis and a cortical cyst as probable predisposing factors. Aetiology and important points concerning diagnosis and therapy are discussed.