The Influence of Nd and Sm on the Structure and Properties of Sol-Gel-Derived TiO2 Powders.

TiO2 nanopowders modified by Nd and Sm were prepared using the sol-gel technique. It was found by XRD analysis that the samples containing Sm are amorphous up to 300 °C, while those with Nd preserve a mixed organic-inorganic amorphous structure at higher temperatures (400 °C). The TiO2 (rutile) was not detected up to 700 °C in the presence of both modified oxides. TiO2 (anatase) crystals found at about 400 °C in the Sm-modified sample exhibited an average crystallite size of about 25-30 nm, while doping with Nd resulted in particles of a lower size-5-10 nm. It was established by DTA that organic decomposition is accompanied by significant weight loss occurring in the temperature range 240-350 °C. Photocatalytic tests showed that the samples heated at 500 °C possess photocatalytic activity under UV irradiation toward Malachite green organic dye. Selected compositions exhibited good antimicrobial activity against E. coli K12 and B. subtilis.

Treatment of Childhood Acute Myeloid Leukemia in Bulgaria.

BACKGROUND: During the last four decades the prognosis of childhood acute myeloid leukemia (AML) has been substantially improved due to an increase in complete remission (CR) rates, event-free survival (EFS) and reduced early mortality. The relapsed AML still remains a therapeutic challenge. AIM: To report the AML treatment results of the Bulgarian pediatric oncohematological centers. MATERIALS AND METHODS: Retrospective analysis of the treatment results of children and adolescents (age from 0 to 20 years) with primary AML. Unified AML BFM- backbone type treatment protocol is used. RESULTS: This study included 97 newly diagnosed patients (44 girls and 53 boys) with AML in Bulgaria between 2003 and 2016. The median age at diagnosis was 10.2 years. The most frequent FAB-morphologic subtype was M2 followed by M4. First complete remission (CR1) was achieved in 83 patients (85.6%). The 13-year EFS was 49%, while the overall survival (OS) was 54.6%. Twenty seven (27.8%) patients relapsed, with only 5 of them being still alive towards the end of the study period. CONCLUSION: The EFS and OS for the children with AML in Bulgaria are comparable with those reported by other European groups. The prognosis of relapsed AML remains still unfavorable for the past 13 years.

Immunophenotypic Modulation of the Blast Cells in Childhood Acute Lymphoblastic Leukemia Minimal Residual Disease Detection.

UNLABELLED: Early clearance of leukemic cells during induction therapy of childhood acute lymphoblastic leukemia (ALL) is a basis for treatment optimization. Currently, the most widely used methods for the detection of minute residual malignant cells in the bone marrow and/or peripheral blood, minimal residual disease (MRD), are PCR and flow cytometry (FCM). Immunophenotypic modulation (IM) is a well known factor that can hamper the accurate FCM analysis. AIM: To report the IM detected by 8-color FCM during the BFM-type remission induction in 24 consecutive MRD-positive samples of children with B-cell precursor ALL and the possible implications for MRD detection. PATIENTS AND METHODS: Between 2010 and 2012 we prospectively followed up the MRD on days 15 and 33 of induction treatment in bone marrow (BM) samples and on day 8 in peripheral blood (PB). The IM was assessed by comparative analyses of the changes in the mean fluorescence intensity of 7 highly relevant antigens expressed by the leukemic cells and normal B-lymphocytes. RESULTS: IM occurred, to different extents, in all analyzed day 15 BM and in most day 33 BM samples. Statistically significant changes in the MFI-levels of four CDs expressed by the leukemic blasts were observed: downmodulation of CD10, CD19 and CD34 and upmodulation of CD20. No changes in the expression of CD38, CD58 and CD45 were noticed. CONCLUSIONS: Measuring the MRD by standardized 8-color flow cytometry helps improve the monitoring of the disease, leading to better therapeutic results. However, the IM of the different antigens expressed by the leukemic blasts should be taken into consideration and cautiously analyzed.

Effect of B2O3 on the Structure, Properties and Antibacterial Abilities of Sol-Gel-Derived TiO2/TeO2/B2O3 Powders.

This paper studies the influence of B2O3 on the structure, properties and antibacterial abilities of sol-gel-derived TiO2/TeO2/B2O3 powders. Titanium(IV) butoxide, telluric(VI) acid and boric acid were used as precursors. Differences were observed in the degree of decomposition of Ti butoxide in the presence of H3BO3 and H6TeO6 acids. The phase transformations of the obtained gels in the temperature range of 200-700 °C were investigated by XRD. Composite materials containing an amorphous phase and different crystalline phases (metallic Te, α-TeO2, anatase, rutile and TiTe3O8) were prepared. Heating at 400 °C indicated a crystalline-to-amorphous-phase ratio of approximately 3:1. The scanning electron microscopy (SEM) analysis showed the preparation of plate-like TiO2 nanoparticles. The IR results showed that the short-range order of the amorphous phases that are part of the composite materials consists of TiO6, BO3, BO4 and TeO4 structural units. Free B2O3 was not detected in the investigated compositions which could be related to the better connectivity between the building units as compared to binary TiO2/B2O3 compositions. The UV-Vis spectra of the investigated gels exhibited a red shift of the cut-off due to the presence of boron and tellurium units. The binary sample achieved the maximum photodegradation efficiency (94%) toward Malachite green dye under UV irradiation, whereas the ternary sample photoactivity was very low. The compositions exhibited promising antibacterial activity against E. coli NBIMCC K12 407.

Protective effects of a superoxide dismutase/catalase mimetic compound against paraquat pneumotoxicity in rat lung.

BACKGROUND AND OBJECTIVE: EUK-134 is one of the most promising of the superoxide dismutase (SOD)/catalase mimetic compounds. The antioxidant effects of EUK-134 were tested in a rat model of paraquat pneumotoxicity. METHODS: Male Wistar rats (n = 72) were divided into three groups: group 1, controls; group 2, paraquat alone; group 3, paraquat + EUK-134. Paraquat dichloride was administered per os at a dose of 80 mg/kg. EUK-134 was injected intraperitoneally at 10 mg/kg 2 h before the paraquat and again 4 h later at 5 mg/kg. RESULTS: On days 1, 3 and 5 after treatment with paraquat alone the LDH activity increased (P = 0.0001, P = 0.00001 and P = 0.03, respectively), and the total protein content increased (P = 0.00002, P = 0.001 and P = 0.01, respectively). The levels of acid phosphatase (AcP) in BAL fluid increased on days 1 and 3 (P = 0.006 and P = 0.04). In lung homogenates paraquat alone increased SOD activity on day 1 and decreased it on days 3 and 5. Combined treatment with paraquat and EUK-134 elevated LDH activity on day 3 (significantly less than paraquat alone) and day 5, elevated the total protein content on day 5 only, and did not change AcP activity. The combination of both agents did not alter SOD activity and decreased catalase activity on day 5 significantly less than treatment with paraquat alone (P = 0.05). CONCLUSIONS: EUK-134, a superoxide dismutase/catalase mimetic compound decreased the pneumotoxic effect of paraquat in rats.

Childhood acute lymphoblastic leukemia presenting with osteoarticular syndrome--characteristics and prognosis.

UNLABELLED: Children with leukemia often present with osteoarticular syndrome as a first complaint thus mimicking juvenile idiopathic arthritis. The objective of the present study was to determine the frequency of osteoarticular syndrome at the onset of acute lymphoblastic leukemia in childhood, the clinical and laboratory specificity of such patients and the prognostic value of osteoarticular syndrome as an initial symptom. PATIENTS AND METHODS: We studied 60 children with acute lymphoblastic leukemia at a mean age of 5 +/- 0.5 years between February 2002 and October 2007. RESULTS: Osteoarticular syndrome was present as an initial symptom of leukemia in 18 (30.5%) patients. The oligoarticular involvement was prevalent--in 8 children (44%). Middle-sized joints were affected more commonly--in 10 patients (55.6%), followed by large joints and spine. Laboratory results in patients with osteoarticular syndrome show more often normal or slightly decreased platelet count, higher values of lactate dehydrogenase and rarely--leukocytosis (> 20 x 10(9)/l). Parablasts in the blood film were detected in 13 children (72.2%) with osteoarticular syndrome. Event-free survival in patients with osteoarticular syndrome is comparable to that of the remaining group of acute lymphoblastic leukemia patients. In conclusion we point out that there should be frequent blood tests in children with osteoarticular syndrome and timely bone marrow biopsy in cases with atypical signs of juvenile arthritis.

Spectrophotometric determination of trace iron by using its catalytic effect on the N-phenylanthranilic acid-potassium periodate reaction.

The analytical features of the reaction between N-phenylanthranilic acid (PAA) and potassium periodate in acidic medium are explored with the aim of improving the catalytic kinetic determination of iron in water samples. In the presence of Fe(II, III), PAA is oxidized by potassium periodate in a formic acid medium to form a violet-colored compound. The reaction is followed spectrophotometrically by measuring the increase in the absorbance of the oxidation product at 525 nm. The variables that affected the reaction rate were investigated and the reaction conditions were established. Calibration graphs are linear in the range of concentrations 2 - 500 ng mL(-1). As low as 10(-8) mol L(-1) Fe(II, III) can be easily determined by the fixed time method. The established catalytic method was successfully applied to the determination of iron in tap water and in pharmaceutical samples.

Protective effect of U-74389G on paraquat induced pneumotoxicity in rats.

Paraquat is a very toxic herbicide and a dangerous pollutant of the environment. It forms reactive oxygen species and increases the lipid peroxidation in the pulmonary cells. Our aim in this study was to estimate the protective effects of the lazaroid U-74389G possessing antilipidperoxidation activity and membrane-stabilizing effect. The experiment was carried out with 96 male Wistar rats. Paraquat dichloride was administered orally at 80mg/kg. The lazaroid U-74389G was injected intraperitoneally twice - 2h before receiving the paraquat with 10mg/kg and four hours later with 5mg/kg. Isolated application of paraquat increased enzyme activities of lactate dehydrogenase (LDH) and acid phosphatase (AcP) and the total protein content in bronchoalveolar lavage fluid (BALF). In the same experimental group the number of polymorphonuclear cells (PMNs) in BALF is elevated significantly on days 1 and 3. The combined treatment with paraquat and U-74389G did not increase the total protein content and the number of PMNs and it elevated the enzyme activities of LDH and AcP significantly less than the alone application of paraquat. It is concluded that the lazaroid U-74389G reduces the pneumotoxic effects of paraquat, estimated by sensitive cytologic and biochemical markers in BALF. The protective effect of U-74389G is well-expressed until day 3 after the treatment.

Central Nervous System Involvement in Henoch-Schonlein Purpura in Children and Adolescents.

Central nervous system (CNS) involvement in Henoch-Schonlein purpura (HSP) is rare but poses diagnostic difficulties. The aim of the study was to establish the frequency of CNS involvement in HSP, to analyze its clinical characteristics and do a literature review. Medical files of patients with HSP admitted at the Department of Pediatrics, Plovdiv, were studied retrospectively for a five-year period (2009-2013). Diagnosis was based on the American College of Rheumatology criteria. Out of 112 children with HSP 1 case (0.9%) had CNS involvement presenting as Posterior Reversible Encephalopathy Syndrome (PRES), which may be a result of CNS vasculitis or arterial hypertension. It was an 8-year-old girl with atypical HSP which started with abdominal pain requiring surgery. On the third day after the operation a transient macular rash and arterial hypertension appeared, followed by visual disturbances, hemiconvulsive epileptic seizures, postictal hemiparesis, and confusion. Head CT showed occipital hypodense lesions and MRT-T2 hyperintense lesion in the left occipital lobe. The patient experienced a second similar episode after 2 weeks when palpable purpura had also appeared. Neurological symptoms and MRI resolved completely. HSP can be an etiological factor for PRES in childhood. Although PRES is a rare complication of HSP, clinicians must be aware of it and avoid diagnostic and therapeutic delays.

Pseudomembranous necrotizing tracheobronchitis caused by Aspergillus spp--contribution of one case with acute myeloid leukemia.

Acute tracheobronchitis is a rare clinical manifestation of respiratory tract invasive aspergillosis, sporadically reported in patients with hematological malignancies against the background of conventional chemotherapy. The authors report on a case of pseudomembranous necrotizing form of histologically proven tracheobronchitis, caused by Aspergillus spp in the time of induction chemotherapy in a patient with acute myeloid leukemia. The clinical evolution is gradual: from mild non-specific manifestations of acute tracheobronchitis against the background of a prolonged fever unaffected by antibiotic therapy to the onset of severe acute respiratory insufficiency and unilateral bronchial obstruction syndrome. Multiple spontaneous expectoration of a part of the bronchial wall was observed in which Aspergillus spp hyphae were histologically proven. Tracheobronchoscopy verified nearly complete obturation of the left main bronchus with thick mucous plugs. Lethal outcome from the infection occurred at the stage of hematological remission because of a massive hemoptysis. The diagnostic methods, therapeutic possibilities and differential diagnosis of this rare infectious complication in immunocompromised patients are discussed.

Effect of Aronia melanocarpa fruit juice on amiodarone-induced pneumotoxicity in rats.

BACKGROUND: The fruits of Aronia melanocarpa (Michx.) Elliot is extremely rich in biologically active polyphenols. OBJECTIVE: We studied the protective effect of A. melanocarpa fruit juice (AMFJ) in a model of amiodarone (AD)-induced pneumotoxicity in rats. MATERIALS AND METHODS: AD was instilled intratracheally on days 0 and 2 (6.25 mg/kg). AMFJ (5 mL/kg and 10 mL/kg) was given orally from day 1 to days 2, 4, 9, and 10 to rats, which were sacrificed respectively on days 3, 5, 10, and 28 when biochemical, cytological, and immunological assays were performed. RESULTS: AMFJ antagonized AD-induced increase of the lung weight coefficient. In bronchoalveolar lavage fluid, AD increased significantly the protein content, total cell count, polymorphonuclear cells, lymphocytes and the activity of lactate dehydrogenase, acid phosphatase and alkaline phosphatase on days 3 and 5. In AMFJ-treated rats these indices of direct toxic damage did not differ significantly from the control values. In lung tissue, AD induced oxidative stress measured by malondialdehyde content and fibrosis assessed by the hydroxyproline level. AMFJ prevented these effects of AD. In rat serum, AD caused a significant elevation of interleukin IL-6 on days 3 and 5, and a decrease of IL-10 on day 3. In AMFJ-treated rats, these indices of inflammation had values that did not differ significantly from the control ones. CONCLUSION: AMFJ could have a protective effect against AD-induced pulmonary toxicity as evidenced by the reduced signs of AD-induced direct toxic damage, oxidative stress, inflammation, and fibrosis.

Impact of thrombophilic genetic factors on pulmonary embolism: early onset and recurrent incidences.

The importance of genetic thrombophilic factors in the development of venous thromboembolism has been increasingly recognized. Factor V Leiden (FVL), prothrombin gene mutation G20210A (FII G20210), genetic variant C677T of the methylentetrahydrofolate reductase (MTHFR), as well as the polymorphism A2 (PlA2) in platelet glycoprotein IIb/IIIa were recently discussed. We analyzed the contribution of genetic thrombophilic factors to the pathogenesis of pulmonary embolism (PE) and their association with the early onset and recurrence of PE using DNA analysis methods. In this case control trial we found thrombophilic genetic variants in 58.8% of 51 patients with PE. FVL was found in 23.5% of the patients versus 7.1% of the 98 controls (p=0.01), PlA2 IIb/IIIa was found in 35.3% vs. 14.3% (p=0.03), and FII G20210A was found in 5.9% vs. 2.0% (NS). Patients with recurrent PE had a very high prevalence of genetic factors, 70.4%. High prevalence of FVL was found in patients under 45 years of age: 39.3% (OR=14.23, 95% CI=1.58-330.03, p=0.01) as well as in patients with recurrent incidence (37%, OR=7.647, 95% CI=2.27-26.44, p=0.001). FVL was also significantly higher in the subgroup of patients with PE combined with deep venous thrombosis (OR=6.500, 95% CI=1.81-23.76, p=0.002) in comparison with patients with isolated PE (OR=2.261, 95% CI=0.50-9.69). The carriers of FVL are at higher risk for early and recurrent PE events. High prevalence of PlA2 in PE patients evidently shows the impact of this polymorphism in PE development. A different treatment should be considered in carriers of thrombophilic defects.