Raman spectroscopy of K x Co2-y Se2 single crystals near the ferromagnet-paramagnet transition.

Polarized Raman scattering spectra of the K x Co2-y Se2 single crystals reveal the presence of two phonon modes, assigned as of the A 1g and B 1g symmetry. The absence of additional modes excludes the possibility of vacancy ordering, unlike in K x Fe2-y Se2. The ferromagnetic (FM) phase transition at [Formula: see text] K leaves a clear fingerprint on the temperature dependence of the Raman mode energy and linewidth. For [Formula: see text] the temperature dependence looks conventional, driven by the thermal expansion and anharmonicity. The Raman modes are rather broad due to the electron-phonon coupling increased by the disorder and spin fluctuation effects. In the FM phase the phonon frequency of both modes increases, while an opposite trend is seen in their linewidth: the A 1g mode narrows in the FM phase, whereas the B 1g mode broadens. We argue that the large asymmetry and anomalous frequency shift of the B 1g mode is due to the coupling of spin fluctuations and vibration. Our density functional theory (DFT) calculations for the phonon frequencies agree rather well with the Raman measurements, with some discrepancy being expected since the DFT calculations neglect the spin fluctuations.

Evidence of superconductivity-induced phonon spectra renormalization in alkali-doped iron selenides.

Polarized Raman scattering spectra of superconducting K(x)Fe(2-y)Se2 and non-superconducting K0.8Fe1.8Co0.2Se2 single crystals were measured in the temperature range from 10 K up to 300 K. Two Raman active modes from the I4/mmm phase and seven from the I4/m phase are observed in the frequency range from 150 to 325 cm(-1) in both compounds, suggesting that the K0.8Fe1.8Co0.2Se2 single crystal also has a two-phase nature. The temperature dependence of the Raman mode energy is analyzed in terms of lattice thermal expansion and phonon-phonon interaction. The temperature dependence of the Raman mode linewidth is dominated by temperature-induced anharmonic effects. It is shown that the change in Raman mode energy with temperature is dominantly driven by thermal expansion of the crystal lattice. An abrupt change of the A1g mode energy near T(C) was observed in K(x)Fe(2-y) Se2, whereas it is absent in non-superconducting K0.8Fe1.8Co0.2Se2. Phonon energy hardening at low temperatures in the superconducting sample is a consequence of superconductivity-induced redistribution of the electronic states below the critical temperature.

Comparison of elastography methods in patients with pancreatic masses.

INTRODUCTION: Endoscopic ultrasonography (EUS) quantitative elastography methods are developed for non-invasive differentiation of pancreatic masses. AIMS: First: To evaluate the diagnostic value of strain ratio (SR) and hue histogram (HH) in patients with pancreatic masses and to determine the cut-off value between pancreatic cancer and focal pancreatitis using a pancreatic tissue close to the mass as a reference area. Second: To calculate new variable HH ratio (HHR) in an attempt to improve sensitivity, specificity and accuracy of the method. METHODS: In a prospective single center study, 149 patients were examined: 105 with the pancreatic masses and 44 controls using Pentax EUS linear probes in combination with Hitachi platforms. SR and HH were automatically calculated by machine software. Finally, two groups were formed: Pancreatic cancer group (58 patients) and focal pancreatitis group (47 patients). All statistical analysis has been made in SPSS 14.0 (SPSS Inc., Chicago, USA). CONCLUSION: Statistical analysis in our study showed that SR with a cut-off value of 7.59 reaches 100% sensitivity and 95% specificity with overall accuracy of 97% (confidence intervals [CI]: 92-97%) in detection of pancreatic cancer. Statistical analysis also showed that HH with a cut-off value of ≥86 reaches 100% sensitivity and just 45% specificity with overall accuracy of 66% (CI: 61-66%) in detection of pancreatic cancer. New variable HHR with cut-off ≥1.153 was slightly better with 98% sensitivity and 50% specificity, with overall accuracy of 69% (CI: 63-70%). SR showed significantly higher specificity compared with HH and HHR. More HH studies on Hitachi platforms are needed.

Lactobacillus acidophilus as a cause of liver abscess in a NOD2/CARD15-positive patient with Crohn's disease.

INTRODUCTION: The development of a fistula and/or an abscess are major complications in patients with Crohn's disease. An abscess can involve any of the major viscera, including the liver and spleen. CASE REPORT: A 27-year-old male patient with a 6-month history of NOD2/CARD15-positive Crohn's disease with stenosis of the terminal ileum, previously treated with corticosteroids, was admitted with fever, chills, diarrhea, fatigue and cachexia. Diagnostic work-up revealed sepsis, an abscess in the right hepatic lobe, multiple abdominal collections and right-sided pleural effusion. It was felt that his poor general condition prevented surgical intervention and complex conservative treatment was initiated. It consisted of total parenteral nutrition, antibiotics, percutaneous drainage of the liver abscess, and thoracocentesis. Pus and blood cultures showed Lactobacillus acidophilus. There was a gradual improvement in the patient's condition and the liver abscess decreased in diameter from 14 to 2 cm. Aminosalicylates and enteral nutrition were gradually introduced. The patient was discharged after 9 weeks in good general condition. CONCLUSION: Although extremely rarely, L. acidophilus can cause hepatic abscess and sepsis. This can be explained by immunologic incompetence due to corticosteroid treatment of Crohn's disease.

Byproducts of oxidative protein damage and antioxidant enzyme activities in plasma of patients with different degrees of essential hypertension.

Despite evidence that essential hypertension (EH) is a state of increased oxidative stress, the data on oxidative protein modifications is lacking. Besides, the role of extracellular antioxidant enzymes in EH has not been systematically studied. Study was performed in 45 subjects with EH and 25 normotensive controls. Patients were divided into three groups according to the 2003 ESH/ESC guidelines (grade 1-3). Plasma protein reactive carbonyl derivatives (RCD) and SH-groups (as byproducts of oxidative protein damage) as well as antioxidant enzyme activities superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase were studied spectrophotometrically and correlated with blood pressure (BP). RCD levels were increased in EH patients compared to controls and correlated significantly with both systolic blood pressure (SBP) (r = 0.495, P<0.01) and diastolic blood pressure (DBP) (r = 0.534, P<0.01). Plasma SH-groups content was significantly lower in all patients with EH, with no correlation with BP. SOD and catalase activity in patients with grade 1 EH were similar to that of controls. Patients with grade 2 and 3 of EH had lower SOD and catalase activity. However, significant correlation with SBP and DBP was observed for catalase only (r = -0.331; P<0.05 and r = -0.365; P<0.05, respectively). EH patients exhibited higher plasma GPX activity compared to those in controls, and it correlated with SBP (r = 0.328; P<0.05). The results presented show that increased oxidative protein damage is present in all grades of EH. In mild hypertension extracellular antioxidant enzyme activities are not decreased, suggesting they are probably not critical in early EH, but could be important in moderate to severe EH.

Evaluation of oxidative stress after repeated intravenous iron supplementation.

Parenteral iron has been recommended for the treatment of iron deficiency in the majority of maintenance hemodialyzed (HD) patients. However, iron supplementation and consequent over saturation of transferrin and high iron levels, may aggravate oxidative stress already present in these patients. This study aimed to further clarify the role of repeated intravenous iron therapy as a supplementary cause of oxidative stress in HD patients. Markers of free radical activities (carbonyl reactive derivatives, CRD, thiol groups, SH, malondialdehyde, MDA) and antioxidant enzyme activities (superoxide dismutase, SOD and glutathione peroxidase, GPX) were determined in plasma and red blood cells (RBC) of 19 hemodialysis patients given a total iron dose of 625 mg (ferrogluconat, Ferrlecit, 62.5 mg). Blood samples were taken before the first and after the last dose of iron. Twenty apparently normal subjects served as healthy controls. Before iron treatment, HD patients exhibited increased concentrations of MDA and CRD in plasma and red blood cells, accompanied with impaired antioxidant capacity. All patients responded to iron therapy with a significant increase in their serum ferritin, serum iron, hemoglobin, and red blood cells levels. However, iron treatment resulted in enhanced oxidative stress in plasma of HD patients, since significant increase in plasma MDA and CRD concentrations, together with a decrease in nonprotein SH groups levels were detected. Supplementation with iron did not significantly influence plasma SOD and GPX activities, nor did any of the red blood cell parameters tested. Our data show that, despite improvement in hematological parameters, an increase in iron stores due to supplementation could also contribute to increased free radical production in HD patients.

Glutathione S-transferase T1-1 activity upregulated in transitional cell carcinoma of urinary bladder.

OBJECTIVES: To perform a systematic functional investigation of different glutathione S-transferase (GST) classes, including GST class Theta (GSTT) member GSTT1-1, in transitional cell carcinoma (TCC) and the surrounding normal uroepithelium of the same individuals. Recently, it was suggested that GSTT1-1 might be an important risk modulator for TCC. METHODS: Tumor samples and surrounding normal uroepithelium were obtained from 24 patients with TCC of urinary bladder. The following substrates with differential specificities were used: 1-chloro-2,4-dinitrobenzene for overall GST activity; 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole for GST Alpha; 1,2-dichloro-4-nitro-benzene for GST Mu; 4-vinylpyridine for GST Pi 1-1(GSTP1-1); and 1,2-epoxy-3-(p-nitrophenoxy)propane for GSTT1-1. RESULTS: GSTP1-1 and GSTT1-1 activities were demonstrated in all uroepithelial and TCC samples, and GST Mu activity was detectable in 11 of 24 patients. In the tumor specimens, significant upregulation of all expressed GST subtypes was observed. The mean GSTP1-1 and GSTT1-1 level in TCC was increased 2-fold and 3.6-fold, respectively, compared with the mean level in the normal uroepithelium (P <0.001). Tumor GSTT1-1 activities correlated statistically significantly with the tumor stage (P <0.05). CONCLUSIONS: In tumors and adjacent normal uroepithelium of patients with TCC, three major cytosolic GST classes, Mu, Pi, and Theta, were expressed. Although the GST isoenzyme pattern in TCC was similar to that of the corresponding normal uroepithelium, during cancer progression a clear tendency toward an increase in all the GST subtypes expressed was noted. For the first time, distinct GSTT1-1 activity levels were demonstrated in human uroepithelium, as well as its pronounced upregulation in TCC.

Comparison of colonoscopies performed under sedation with propofol or with midazolam or without sedation.

BACKGROUND: Previous studies have shown that some patients are not able to tolerate colonoscopy without sedation because of low pain threshold, anxiety, colonic sensitivity and anatomical variations. Benzodiazepines are most commonly used, often in combination with pethidine. Our study compares sedation with propofol to midazolam and colonoscopy without sedation. METHODS: In this study 147 patients were examined. The patients were divided into three groups: The first group included patients in whom propofol was used for sedation, the second group included patients sedated with midazolam, and the third group was comprised of patients who received no sedation. Oxygen saturation and heart rate were recorded continuously by pulse oxymetry. Arterial blood pressure (BP) was monitored at 3-min intervals. RESULTS: A decrease in blood pressure and heart rate was documented in the first two groups (P < 0.001), whereas in group 3 we found an increase in both BP and heart rate (P < 0.001). Oxygen saturation dropped below 90 % in 11/102 patients sedated with propofol and in 9/23 sedated with midazolam. Two of 22 patients in whom no sedation was used were found to have oxygen saturation below 90 %. The recovery time was shorter (7 min) in group 1 (propofol) than in group 2 (midazolam), in which it was found to be 20 min. CONCLUSIONS: Our results showed that propofol provided good sedation with excellent pain control, a short recovery time and no significant haemodynamic side effects.

[Palliative treatment of malignant esophageal obstruction with a new endoscopically administered self-expanding nitinol stent: case report]. / Palijativni pristup malignoj opstrukciji jednjaka endoskopskom primjenom novog samosireceg (self-expanding) nitinolskog stenta; prikaz bolesnice.

The endoscopic methods of palliative treatment in malignant esophageal stenoses caused by neoplasm which have been performed so far unfortunately do not provide permanently satisfying results. The implantation of self-expanding stents with the purpose of removing malignant esophageal obstructions has recently become the most acceptable method of treatment. By using that method it is possible to reduce or even completely remove difficulties in swallowing. In that way a significant improvement in life quality of patients with inoperable esophageal cancer is possible. The various types of metal endoprostheses used for the palliative treatment of esophageal malignant stenoses are described in this paper. Here is also presented a case of nitinol stent implantation in a 50 year old woman suffering from esophageal cancer. This type of therapeutic treatment has been applied in Croatia for first time.

[Treatment of malignant bile duct obstruction with a metal stent. Case report]. / Rjesenje maligne opstrukcije zucovoda metalnim stentom. Prikaz slucaja.

In the case report we describe endoscopic implantation of endoprosthesis in the periampullar area in a 87 year old female patient with obstructive jaundice and cholangitis caused by pancreatic tumour. This is the first time that this procedure was successfully performed in Croatia.

Primary malignant melanoma of the rectum: a case report.

The aim of the study was to describe the diagnostic procedure, indications for operation and operative result in a patient with primary malignant melanoma of the rectum. In the patient, hospitalized at the Department of Surgery, School of Medicine in Zagreb, a malignant melanoma of the rectum was diagnosed by rectoscopy and histology. Tumor staging was determined by endorectal ultrasonography. Operation was indicated for malignant disease with partial obstruction of the rectum. Since the tumor was locally inoperable, with liver metastases a palliative operative procedure (sigmoidal colostoma) was performed. The operative finding confirmed the tumor stage obtained by ultrasonography. The patient died 5 months after the operation due to widespread dissemination of the malignant disease. Thereby, the accuracy of preoperative tumor staging by ultrasonography was confirmed. We believe that, in view of its accuracy, endorectal ultrasonography can be used for tumor staging in patients with primary melanoma of the rectum. Therefore, expensive diagnostic imaging methods like CT and MRI are no longer necessary.

Percutaneous pancreatography under ultrasonographic guidance.

PURPOSE: The aim of the study was to evaluate percutaneous pancreatography as an alternative method for pancreatic duct visualisation in patients with pancreatic disease. MATERIAL AND METHODS: In 21 patients with pancreatic disease and previously unsuccessful ERCP, puncture of the pancreatic duct was carried out under ultrasonographic guidance with an 0.7-mm Chiba needle, and contrast injection was made under fluoroscopic control in the pancreatic duct. RESULTS: The procedure was successful in 18 patients (86%). In 10 patients, chronic pancreatitis was found, and in 8 patients, pancreatic carcinoma. CONCLUSION: Percutaneous pancreatography is a good alternative method for visualisation of the pancreatic duct in patients with pancreatic disease and previously unsuccessful ERCP.

Comparison of injection sclerotherapy and laser photocoagulation for bleeding peptic ulcers.

BACKGROUND AND STUDY AIMS: The most widely used endoscopic procedures in the management of patients with bleeding peptic ulcer are at present sclerotherapy and thermal methods. In an attempt to assess the most effective method of achieving hemostasis, we compared injection sclerotherapy and laser photocoagulation in terms of the efficacy of initial hemostasis, rebleeding, need for surgery, mortality, and the appearance of the ulcer after the hemostatic procedure. PATIENTS AND METHODS: In this prospective, randomized trial, 160 patients were treated with injection sclerotherapy (1% polidocanol), and 155 patients with laser photocoagulation (Nd:YAG laser) in cases of Forrest I, Forrest IIa, and Forrest IIb hemorrhage. The bleeding activity was classified according to the modified Forrest criteria. Polidocanol injection and Nd:YAG laser photocoagulation were not preceded by epinephrine administration. RESULTS: There were no significant overall differences between the groups in the outcome in terms of definitive hemostasis, rebleeding, urgent surgery, and death (p = 0.487). In the case of the subgroup with Forrest I lesions, laser photocoagulation was more efficacious than sclerotherapy (p = 0.0078). In the Forrest IIa and Forrest IIb subgroups, the two methods were equally effective (p = 0.202 and 0.513 respectively). In the sclerotherapy patients, definitive initial hemostasis in Forrest IIa was achieved in 100%, whereas in the laser group this rate was 92%, with 28% of patients initially developing hemorrhage after one or two laser pulses. Ulcer healing was slower following sclerotherapy than after photocoagulation. CONCLUSION: Injection sclerotherapy and laser photocoagulation are equally effective in achieving definitive hemostasis in bleeding peptic ulcers. Laser photocoagulation is more efficacious in patients with active bleeding, whereas injection sclerotherapy is more effective in patients with a nonbleeding visible vessel.

[The effect of atmospheric conditions on the occurrence of peptic ulcer hemorrhage]. / Utjecaj atmosferskih uvjeta na ucestalost krvarenja iz peptickog ulkusa.

The influence of atmospheric factors on the frequency of bleeding from the peptic ulcer was studied within the period from April 1, 1984, to March 31, 1989, consequently through 1826 days. The average daily atmospheric pressure, the average daily temperature and the relative humidity have been examined. There were 1102 cases of bleeding peptic ulcer, 537 bleeding gastric ulcers and 565 bleeding duodenal ulcers. During the study period there were 454 days with bleeding form ventricular ulcer and 465 days with bleeding from duodenal ulcer. There was 793 days with bleeding form either lesion. The discriminatory analysis demonstrated that the atmospheric pressure is the variable that discriminates the days with bleeding and the days prior to bleeding from the days without bleeding. The relative humidity occurs as the relevant discriminatory variable in the days prior to bleeding for the duodenal ulcer group and for the entire group. The centroids of the discriminatory function demonstrate that the days with ulcer bleeding are characterized by the fall of atmospheric pressure. The factor analysis of meterological variables clearly shows the correlation of the atmospheric pressure and the bleeding regardless to the localisation of bleeding ulcer, where the greatest number of bleedings is correlated with lower atmospheric pressure. We conclude that the incidence of bleeding form the peptic ulcer of the stomach and duodenum correlates in great measure with low atmospheric pressure in the days prior to bleeding and in the days of bleeding, as well as with fall of atmospheric pressure in the days of bleeding with respect to previous day.(ABSTRACT TRUNCATED AT 250 WORDS)

Prophylactic administration of ranitidine after sclerotherapy of esophageal varices.

The present trial was carried out to determine the usefulness of H2-receptor antagonist drug therapy for the prevention of esophageal bleeding and esophageal varices in patients who underwent sclerotherapy. According to randomization, out of the 58 patients, 28 received, along with the usual standard therapy, ranitidine and 30 received placebo. Ranitidine, 50 mg, was administered intravenously over a period of 3 days every 8 hours, and then 150 mg of ranitidine was given per os in the evening for one month. For improvement of hemostasis and during the elective sclerotherapies, 1% polidocanol was used as the sclerosant. During each puncture, 2 ml was injected. Injections were paravasal and intravasal. After sclerotherapy, endoscopic examinations were carried out on the third day and one month later. Necrosis was noted in 42% of the patients and esophageal mucosal inflammation in 26%. Esophageal ulcers did not occur. There was no statistically significant difference between the two groups in terms of age, sex ratio, cause of liver cirrhosis, and the Child's classification. The size of the esophageal varices had no effect on the development of esophageal mucosal changes in correlation with the quantity of sclerosant. The comparison of the two groups of patients, sclerosed for hemorrhage and sclerosed electively, showed no statistically significant difference regarding esophageal mucosal changes. No differences between the ranitidine and placebo groups of patients were observed in this indication. It can be concluded that esophageal mucosal changes probably arise as a consequence of the sclerosant, its concentration, quantity and mode of application.(ABSTRACT TRUNCATED AT 250 WORDS)