Anharmonicity due to electron-phonon coupling in magnetite.

We present the results of inelastic x-ray scattering for magnetite and analyze the energies and widths of the phonon modes with different symmetries in a broad range of temperature 125 < T < 293 K. The phonon modes with X(4) and Δ(5) symmetries broaden in a nonlinear way with decreasing T when the Verwey transition is approached. It is found that the maxima of phonon widths occur away from high-symmetry points, which suggests the incommensurate character of critical fluctuations. Strong phonon anharmonicity induced by electron-phonon coupling is discovered by a combination of these experimental results with ab initio calculations which take into account local Coulomb interactions at Fe ions. It (i) explains observed anomalous phonon broadening and (ii) demonstrates that the Verwey transition is a cooperative phenomenon which involves a wide spectrum of phonons coupled to the electron charge fluctuations condensing in the low-symmetry phase.

Influence of Doping on the Topological Surface States of Crystalline Bi2Se3 Topological Insulators.

We present STM/STS, ARPES and magnetotransport studies of the surface topography and electronic structure of pristine Bi2Se3 in comparison to Bi1.96Mg0.04Se3 and Bi1.98Fe0.02Se3. The topography images reveal a large number of complex, triangle-shaped defects at the surface. The local electronic structure of both the defected and non-defected regions is examined by STS. The defect-related states shift together with the Dirac point observed in the undefected area, suggesting that the local electronic structure at the defects is influenced by doping in the same way as the electronic structure of the undefected surface. Additional information about the electronic structure of the samples is provided by ARPES, which reveals the dependence of the bulk and surface electronic bands on doping, including such parameters as the Fermi wave vector. The subtle changes of the surface electronic structure by doping are verified with magneto-transport measurements at low temperatures (200 mK) allowing the detection of Shubnikov-de Haas (SdH) quantum oscillations.

The effects of venous hemodynamics on angiogenesis in morbid obese.

BACKGROUND: It is known that obesity is associated with alterations in blood rheology and venous hemodynamics. Another recent study has confirmed that adipose tissue is actively involved in angiogenesis through secretion of biologically active substances. OBJECTIVE: The aim of this study was to investigate the impact on the venous haemodynamics of the femoral vein on angiogenesis status in morbidly obese patients. METHODS: We studied venous haemodynamics and angiogenesis in a prospective study of obese and non-obese individuals. The venous wall shear stress (WSS) was calculated from the blood viscosity and the shear rate was calculated assuming Newton's law. Angiogenesis was detected using Bio-Plex Pro Human Angiogenesis Multiplex Assays (Bio-Plex 200 Systems). RESULTS: The shear rate (P < 0.000005) and the wall shear stress (P < 0.01) were significantly lower in the obese patients compared with the control subjects. All angiogenesis biomarkers were significantly higher in obese patients compared to the control group. Multivariate analyses identified waist circumference as an independent predictor for PECAM-1 (ß = - 0.69, P < 0.0001) and for VEGF (ß = - 0.60, P < 0.001); analyses identified WSS as an independent predictor for follistatin (ß = - 0.59, P < 0.001), for PECAM-1 (ß = - 036, P < 0.05) and for VEGF (ß = - 0.42, P < 0.05). For angiopoietin 2 (ß = - 0.35, P = 0.064) and HGF (ß = - 0.31, P = 0.074), WSS tended to be a significant predictor. CONCLUSIONS: The results indicated that obesity-associated decreases in shear stress of the venous system lead to upregulation of angiogenesis, expressed by increased levels of endogenous positive regulators of angiogenesis.

[Iliac vessels malformations as a cause of gluteal varices]. / Malformacje naczyn biodrowych jako przyczyna zylaków posladków.

Gluteal varices are caused by different malformations (congenital or other disorders) within pelvic vessels. They are usually congenital, rarely acquired disorders. The rarity of incidence, diagnostic difficulties and sometimes ineffective methods of treatment made the authors of this article to present a case of 51-year-old patient with hemorrhoids with concomitant left gluteal varices caused by internal iliac artery-vein fistula.

[Metastasis to brain from rectal cancer as the first manifestation of neoplasmatic disease]. / Przerzut raka odbytnicy do osrodkowego ukladu nerwowego jako pierwszy objaw choroby nowotworowej.

Cerebral metastases from colorectal cancer are uncommon. They are usually a late manifestation of the neoplasmatic disease. The symptoms aren't always typical. We report the case of 52-year-old woman in whom the first manifestation of the disease was metastasis to brain.

[Concentration of glutathione (GSH), ascorbic acid (vitamin C) and substances reacting with thiobarbituric acid (TBA-rs) in single human brain metastases]. / Stezenie glutationu (GSH), kwasu askorbowego (witamina C) oraz substancji reagujacych z kwasem tiobarbiturowym (TBA-rs) w pojedynczych przerzutach nowotworowych do mózgu.

The aim of the study was to estimate the concentration of glutathione (GSH), ascorbic acid (vitamin C) and thiobarbituric acid (TBA-rs) in single human brain metastases and histologically unchanged nerve tissue. The research was conducted on fragments of neoplasmatic tissue collected from 45 patients undergoing surgery in the Department of Neurosurgery, Medical University of Bialystok in years 1996-2002. Concentration of GSH was evaluated using the GSH-400 method, vitamin C using the method of Kyaw and TBA-rs using the method of Salaris and Babs. It has been found that there is a decrease of concentration of GSH and vitamin C and a considerable increase (p < 0.05) of concentration of TBA-rs in investigated single brain human metastasis in correlation to the concentration of the mentioned above substances in unchanged nerve tissue.

Circadian rhythm of melatonin in patients with colorectal carcinoma.

OBJECTIVE: The aim of the study was pineal gland function assessment on the base of daily rhythm study and mean daily melatonin (MEL) concentrations in serum in patients with colorectal carcinoma. MATERIAL AND METHODS: Studies were performed in 12 women at the age of 63.17+/-5.90 years and 21 men aged 58.95+/-11.32 years with large intestine adenocarcinoma. The control group consisted of 28 healthy volunteers at comparable age. During the circadian study blood samples for the measurement of melatonin (MEL) were collected every 4 hours during 12 h. MEL concentrations were assessed with the use of RIA methods. Statistical analysis of circadian rhythms of MEL was carried out with the use of cosinor method according to Halberg. RESULTS: Existence of daily rhythm of MEL secretion was shown in all studied groups. A significant decrease of amplitude of rhythm and secretion of MEL at nocturnal hours in comparison with the control group was shown in the group of women with large intestine carcinoma. A significant decrease of mesor value and amplitude of MEL rhythm as a consequence of decrease of MEL secretion at nocturnal and morning hours was observed in the group of ill men. CONCLUSIONS: Decrease in melatonin circadian rhythm amplitude as a consequence of its lowered nocturnal secretion occurred in all patients with colorectal carcinoma. Abnormalities in daily rhythm of melatonin secretion were more intensified in men with large intestine carcinoma, which leads to suppression of mean daily hormone concentration.

[Evaluation of surgical treatment results in extreme lateral lumbar disc prolapsed after 12 months of follow-up]. / Ocena wyników chirurgicznego leczenia krancowobocznie wypadnietego jadra miazdzystego w ledzwiowej czesci kregoslupa po dwunastomiesiecznym okresie obserwacji pooperacyjnej.

In 1988-1997, patients with extreme lateral disc prolaps (KBWJM) were operated on the Department of Neurosurgery Medical Academy of Bialystok. Females accounted for 4.9% (2 cases) and 95.1% were males (39 cases) with age range 41-60 years. During a study of clinical state 12 months after the operation, we found in 75.6% of patients good and very good results of the surgical treatment of KBWJM. During that period of time, two patients (4.9%) were reoperated out of 41 all patients.

[Activity of glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R) and superoxide dismutase (SOD-1) in single brain metastasis]. / Aktywnosc peroksydazy glutationowej (GSH-Px), reduktazy glutationowej (GSSG-R) i dysmutazy nadtlenkowej (SOD-1) w pojedynczych przerzutach nowotworowych do mózgu.

The aim of the study was to evaluate the activity of glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R) and superoxide dysmutase (SOD-1) in the single brain metastases. The activity of the GSH-Px was evaluated with the use of spectrophotometry, GSSG-R was evaluated basing on the method of Mize and Langdon and SOD-1 with Sykes et al. method. The examinations were carried out in 36 specimens (10 specimens of healthy brain tissue, 12 specimens of brain metastases, 14 specimens of glioma multiforme). The statistical analysis revealed significant increase (p < 0.001) of GSH-Px and GSSG-R activity within the single brain metastases in comparison with the healthy brain tissue.

Evaluation of antioxidant enzymes activity and concentration of non-enzymatic antioxidants in human brain tumours.

UNLABELLED: The purpose of our research was to assess the activity of GSH-Px, GSSG-R, SOD-1 and concentration of GSH, Vit.C and reactive substances with thiobarbituric acid, in brain tumours with Ist, IInd, IIIrd and IVth levels of biological malignancy. The research was conducted in 105 samples obtained from patients undergoing surgery in the Department of Neurosurgery of the Medical University of Bialystok between the years 1996-2001. The obtained values of the above enzyme activities and the concentration of the examined substances in brain tumours were compared to the control values determined in 15 samples of histopathology unchanged nerve tissue. THE RESULTS: The increase in all enzymes activities in brain tumours is statistically significant (p < 0.05) as compared to the control level in normal nerve tissue alto a significant decrease (p < 0.05) of the GSH and ascorbate concentration and a significant increase (p < 0.05) in the level of thiobarbituric acid-reactive substances in the examined brain tumours was found in comparison to the concentration of the above substances in normal nerve tissue.

The decrease in antioxidant potential in human brain tumours.

UNLABELLED: The objective of our research was to estimate the activity of superoxide dismutase (SOD-1), glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-R), as well as the concentrations of free oxygen radicals "sweepers" (GSH, Vit.C) and the concentrations of the substances reacting with thiobarbituric acid in brain tumours with II, III and IV level of biological malignancy. The research was conducted on 61 samples obtained from the patients operated in the Department of Neurosurgery of the Medical Academy of Bialystok between the years 1996 and 2000. The obtained values of the above enzyme activities and of the concentrations of the examined substances in brain tumours were compared to the adequate values determined in 10 samples of histopathologically unchanged nerve tissue. THE RESULTS: the increase of all enzymes activities in brain tumours is statistically significant (p < 0.05) as compared to the adequate activity level in normal nerve tissue. The significant decrease (p < 0.05) of the GSH and ascorbate concentration and the significant increase (p < 0.05) of the level of the thiobarbituric acid--reactive substances in the examined brain tumours was found in comparison to the adequate concentration of the above substances in normal nerve tissue.