Subchronic methionine load induces oxidative stress and provokes biochemical and histological changes in the rat liver tissue.

The aim of this study was to assess the effects of L-cysteine (Cys) (7 mg/kg) and N-acetyl-L-cysteine (NAC) (50 mg/kg) in the rat liver caused by subchronic i.p. application of methionine (Met) (0.8 mmol/kg) during 21 days. Malondialdehyde (MDA) concentration, glutathione content (GSH), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and acetylcholinesterase (AchE) activities were determined in the liver tissue and activities of liver enzymes (AST, ALT, ALP, and GGT) and concentrations of total proteins and albumin were determinated in plasma/serum. Catalase, superoxide dismutase, and acetylcholinesterase activities were increased by Cys and NAC. Met caused periportal mononuclear infiltration and rare focal necrosis of hepatocytes. In Cys- and NAC-supplemented groups, intracellular edema and microvesicular fatty changes without necrosis were noticed. We observed decrease of AST, ALT, and ALP activity in the methionine-treated group. Our results indicate that Cys and NAC application can increase activity of antioxidative enzymes and prevent intensive histological changes in liver in condition of subchronic methionine exposure.

The effect of subchronic supplementation with folic acid and l-arginine on homocysteine-induced seizures.

The aim of the present study was to examine the effect of subchronic co-administration of folic acid (F) and l-arginine (A) on behavioural and electroencephalographic (EEG) characteristics of dl homocysteine thiolactone (H) induced seizures in adult rats. The activity of membrane ATPases in different brain regions were also investigated. Rats were treated with F, A, or vehicle for 15 days (regimen: F 5 mg/kg + A 500 mg/kg (F5A500); F 10 mg/kg + A 300 mg/kg (F10A300)). Seizures were elicited by convulsive dose of H (H, F5A500H, F10A300H) Subchronic supplementation with F and A did not affect seizure incidence, number of seizure episodes, and severity in F5A500H and F10A300H groups vs. H group. However, a tendency to increase latency and decrease the number of seizure episodes was noticed in the F10A300H group. EEG mean spectral power densities during ictal periods were significantly lower in F10A300H vs. H group. The activity of Na+/K+-ATPase and Mg2+-ATPase was significantly increased in almost all examined structures in rats treated with F and A. We can conclude that subchronic supplementation with folic acid and l-arginine has an antiepileptic effect in dl homocysteine thiolactone induced epilepsy.

Electrolytes based on alkoxysilyl-functionalized ionic liquids: viscoelastic properties and conductivity.

Ionic liquids can be successfully used as electrolytes in electrochemical devices when they are in their quasi-solid state. Among several methods of solidification, a sol-gel process was chosen and a set of alkoxysilyl-functionalized iodide imidazolium-based ionic liquids were synthesized. The electrolytes were prepared by mixing these ionic liquids with a non-polymerisable ionic liquid (1-methyl-3-propylimidazolium iodide (MPIm(+)I(-))). Iodine was dissolved in an electrolyte matrix in order to form an I3(-)/I(-) redox couple. The change of the structure from sol to gel was followed by rheological tests in order to show the effect of different rheological parameters on the gelation process. The solvolysis with glacial acetic acid and condensation were followed by rheological experiments on the samples taken from a batch, and in situ on the rheometer. The formed three-dimensional sol-gel networks of various alkoxysilyl-functionalized ionic liquids differed in their microstructures and viscoelastic properties that were correlated with conductivity. The results show that the conductivity of approximately 10(-3) S cm(-1) at room temperature was achieved for the gels with relatively high values of elastic modulus and noticeable viscous contribution. It is shown that not only the viscosity but also the viscoelastic behavior and especially the relationship between viscous and elastic moduli (phase shift) together with the time of gelation are essential for the high conductivity of electrolytes.

Exercise decreases susceptibility to homocysteine seizures: the role of oxidative stress.

The aim of the study was to examine the effects of chronic exercise training on seizures induced by homocysteine thiolactone (HCT) in adult rats. Rats were assigned to: sedentary control; exercise control; sedentary+HCT; exercise+HCT group. Animals in the exercise groups ran 30 min daily on a treadmill for 30 consecutive days (belt speed 20 m/min), while sedentary rats spent the same time on the treadmill (speed 0 m/min). On the 31st day, the HCT groups received HCT (8.0 mmol/kg), while the control groups received vehicle. Afterwards, convulsive behavior and EEG activity were registered. Lipid peroxidation, superoxide dismutase (SOD) and catalase (CAT) activity were ascertained in the rat hippocampus. No signs of seizures were registered in sedentary and exercise control rats. Seizure latency was increased, while number of seizure episodes and spike-and-wave discharges (SWD) in EEG were decreased in the exercise+HCT compared to the sedentary+HCT group. Seizure incidence, the severity thereof and duration of SWDs were not significantly different between these groups. Exercise partly prevented increase of lipid peroxidation and decrease of the SOD and CAT activity after HCT administration. These results indicate beneficial effects of exercise in model of HCT-induced seizures in rats, what could be, at least in part, a consequence of improved antioxidant enzymes activity.

Clinical efficacy, safety and pharmacokinetic properties of the plasma-derived factor IX concentrate Haemonine in previously treated patients with severe haemophilia B.

Plasma-derived factor IX (FIX) concentrate remains an important choice for replacement therapy in haemophilia B patients. Haemonine is a high purity double-virus inactivated human plasma-derived coagulation FIX concentrate (pdFIX). Aim was to evaluate the clinical efficacy, safety and pharmacokinetic properties of Haemonine in three prospective, open-label uncontrolled studies and a compassionate use program in previously treated patients with severe haemophilia B. Long-term efficacy and safety were investigated in 29 patients treated prophylactically and, in addition, treatment on-demand (TOD) in the case of acute haemorrhage. Pharmacokinetic properties were assessed in 14 patients at baseline and after 3 months of regular treatment. Pharmacokinetic parameters were in accordance with published data and remained nearly unchanged over time, notably recovery and half-life. Mean terminal elimination half-life was 27.6 h and 25.0 h, mean incremental recovery (IU dL(-1) /IU kg(-1)) was 1.55 and 1.60, at baseline and 3 months, respectively. Haemonine was shown to be effective in preventing and controlling bleeds. 55.2% (16/29) of patients were free of bleeds under prophylaxis. 38 haemorrhages occurred, 42% (16/38) required treatment and 87.5% (14/16) resolved after a single infusion, 12.5% after 2 infusions. All responses reported on haemorrhages were rated as 'excellent' or 'good'. Moreover, 'excellent' haemostatic efficacy was demonstrated in 12 surgeries with no complications. Few adverse events (AEs) and no thrombogenic complication, nor induction of FIX inhibitory antibodies were observed. Haemonine is effective, safe and well tolerated in long-term prophylaxis, TOD and when applied after minor and major surgeries.

Mycophenolate mophetil therapy for chronic immune thrombocytopenic purpura resistant to steroids, immunosuppressants, and/or splenectomy in adults.

Treatment options are limited in patients with chronic immune thrombocytopenic purpura (ITP) which has been unresponsive to corticosteroids and/or splenectomy. Mycophenolate mophetil (MMF) is effective in many autoimmune disorders including severe and refractory ITP through its targeting of T-cell and B-cell lymphocytes. We report on the efficacy of MMF (1.5-2 g/day) in 16 adults with severe steroid-resistant ITP. MMF was administered for at least 12 weeks (median 37 weeks, range 14-64 weeks). Patients comprised of 10 females and six males, with median pre-treatment platelet counts of 8 × 10(9)/L, median age of 55 years, median ITP duration of 58 months and a median of four prior treatments (range 3-8); nine had been previously splenectomized. Eleven patients (69%) responded after 12 weeks of MMF: 6 (55%) achieving complete remission (CR) and five (45%) achieved partial remission (PR). MMF therapeutic responses were better in those patients who had had fewer prior treatments (p<0.05), and were independent of patient age, sex, disease duration, and splenectomy status (p>0.05). Five of the 11 responders (45%; 3CR/2PR) had sustained remissions; however, six responders (55%; 3CR/3PR) relapsed after median of 14 weeks (range 9-20). Three of the six relapsing patients responded to MMF reinstitution achieving stabile PRs; three were left untreated as none had further bleeding and their platelets remained at "safe" levels (median 30 × 10(9)/L). The MMF treatment was well tolerated; one heavily pretreated patient developed a bronchopneumonia and a second had an episode of diarrhea. MMF used as a second-line agent can produce a sustained response in severe ITP which has been unresponsive to steroid and/or splenectomy without major toxicity.

Expression of VEGF and microvessel density in patients with multiple myeloma: clinical and prognostic significance.

The conflicting data are reported on the clinical significance of VEGF deregulation and intensity of angiogenesis in multiple myeloma. The aim of this study was to evaluate the incidence and prognostic significance of VEGF expression and microvessel density (MVD) in multiple myeloma, as well as the relationship of their expression with selected clinical data, histological features, and proliferative activity of myeloma cells. We analyzed bone marrow biopsy specimens obtained from 59 patients with newly diagnosed multiple myeloma. Expression of VEGF and MVD was analyzed using standard immunohistochemical method (antibodies against VEGF and CD34, respectively) on B5-fixed and routinely processed paraffin-embedded bone marrow specimens. MVD was estimated by counting the number of microvessels in three "hot spots" at 400x magnification. VEGF immunoreactivity was estimated on the basis of intensity and percentage of positive plasma cells. VEGF was expressed in 47/59 (79.7%) specimens. There was no significant correlation between VEGF overexpression and age, clinical stage, the extent of osteolytic lesions, type of monoclonal protein, hemoglobin concentration, platelet count, serum concentration of creatinine, calcium, and albumins, the extent of bone marrow infiltration, histological grade, and proliferative activity index (measured with Ki-67 immunoreactivity). No significant difference was observed regarding the overall survival between VEGF-positive and VEGF-negative patients (29 vs. 34 months, P = 0.8). Median MVD was 15, ranging from 1 to 89 microvessels per three "hot spots". There was significant correlation between MVD and histological grade, the extent of bone marrow infiltration, and proliferative activity. Significant difference was observed regarding the overall survival between patients with low MVD (<15) and patients with high MVD (> or = 15) (46 vs. 22 months, P = 0.009; univariate analysis). The results of this study did not reveal clinical significance of VEGF overexpression in multiple myeloma. On the contrary, the extent of bone marrow angiogenesis is an indicator of biological potency of malignant clone and a predictor of poor survival in newly diagnosed myeloma.

Triple-way therapeutic approach for paraganglioma-dependent erythrocytosis: drugs and surgery plus "multi-manner" apheresis.

Paragangliomas are tumors arising from the extra-adrenal paragangliar neural crest cells. The sympathoadrenal neuroendocrine system consists of extra-adrenal paragangliar cellular layer along the paravertebral and para-aortic axis, and the adrenal medullae. Paraganglioma should be included in the differential diagnosis of secondary erythrocytosis due to its possible ectopic erythropoietin (EPO) secretion. Thus, in this report we present a 24-year-old female patient with onset of unregulated ectopic EPO secretion, and consecutive erythrocytosis followed by hypertension, secondary to paraganglioma of multifocal retroperitoneal localization. Clinical, laboratory, and radiological investigations confirmed both an elevated EPO level and the presence of multiple paraganglioma. This paraneoplastic-mediated medical condition with high risk of cellular hyperviscosity syndrome (CHVS) requires prompt diagnosis and rapid therapeutic interventions. Initially, simple phlebotomy procedures were used; following that, tumors were surgically removed. In the course of the disease, this tumor relapsed, and urgent apheresis, as a treatment of life-threatening state, was used. The therapy performed resulted in a rapid blood viscosity depletion and a significant (P < 0.01) serum EPO reduction, as well as the general clinical benefit. Therefore, we conclude that the use of our own "multi-manner" apheresis (erythrocythapheresis plus plasma exchange), for long-time interval (until further causative therapy), effectively cross-bridged the possible hazards of EPO-dependent CHVS.

Molecular characteristics and prognostic significance of Bcl-2/IgH gene rearrangement in Serbian follicular lymphoma patients.

Follicular lymphoma (FL) is characterized by the presence of a t(14;18) chromosomal translocation that results in overexpression of bcl-2 protein. Bcl-2/IgH gene rearrangement is detected in 80-90% of follicular lymphomas in Western countries. The aim of this study was to analyze the bcl-2/IgH rearrangement in FL lymphoma patients in Serbia, by PCR technique, correlate molecular findings with clinical characteristics and outcome and assess the prognostic significance of these rearrangements. One hundred-seven patients (median age, 54 years; male/female ratio:60/47) diagnosed with FL were included in the study. DNA samples were obtained from paraffin embedded lymphoid tissue of patients. Bcl-2/IgH rearrangement was assessed for the major breakpoint region (MBR), 5' MBR and the minor cluster region (mcr) breakpoints by PCR technique. We detected a t(14;18) in 81.3% (87/107) of patients. The distribution of bcl-2-IgH rearrangement was as follows: 88,5% (77/87) in MBR breakpoint, 10,35% (9/87) in 5' MBR, whereas mcr bcl-2-IgH rearrangement was observed in one patient (1.15%). No rearrangements were detected in remaining 20 patients (18.7%). This is the first analyses of the frequency of the bcl-2/IgH gene rearrangement in Serbian FL patients, as well as in Eastern European countries. There was no correlation between presence of bcl-2/IgH gene rearrangement and clinical outcome of disease. Incidence of bcl-2/IgH gene rearrangement in Serbian FL patients is relatively high, and similar to frequency in Western countries. Presence of this rearrangement in tumor tissue is not of prognostic significance.

Systemic lupus Erythematosus and IgA multiple myeloma: a rare association?

The coexistence of systemic lupus Erythematosus (SLE) and multiple myeloma (MM) is uncommon and the pathogenetic mechanisms underlying this association remain unclear. We report the case of a woman who was diagnosed with SLE in 1993 aged 57, then developing IgA lambda type MM in the IIB clinical stage 7 years later. The SLE was treated successfully with methylprednisolone and chloroquine, and low dose maintenance steroid was continued with bisphosphonate protection until December 1994 when she suffered multiple vertebral fractures. She continued to receive 4 mg alternate day methylprednisolone and calcitonin until she decided to discontinue her own treatment 2 years later. In 2000, while still in stable SLE remission, she was diagnosed with MM. Protein electrophoresis revealed the IgA lambda paraprotein (40.5 g/l) and she had a Bence Jones (BJ) proteinuria of the lambda light chain type. Bone marrow trephine biopsy revealed a massive patchy infiltrate of abnormal plasmocytes (70%), while an extensive x-ray skeletal survey did not show any new fractures or osteolysis. The patient was treated according to the VMCP protocol without attaining a plateau phase. There was a similar poor clinical response to second and third line treatments (VAD, Thalidomide, Melphalan, and high dose dexamethasone). After 4 years of refractory disease the patient died from severe bilateral pneumonia. This case is discussed with reference to the literature.

Immunophenotypic profile and clinical characteristics in patients with advanced stage mantle cell lymphoma.

The objective of this study was to evaluate immunophenotypic profile along with clinical follow-up in patients with advanced stage mantle cell lymphoma (MCL), and their possible influence on overall survival (OS). Bone marrow (BM) cell and/or peripheral blood mononuclear cell flow cytometric analyses of the following antigens were performed: HLA-DR, CD19, CD20, CD22, CD23, CD25, CD10, SmIg, kappa, lambda, CD79b, CD38, FMC7, CD3, CD2, and CD5. There were 14 patients in IV CS, and 26 patients in CS V. All patients were treated with CHOP. Immunological markers showed a typical phenotype (CD5+ CD23-, Cyclin D1) in all cases. Pathohistological type of BM infiltration was predominantly diffuse (72.5%), and in remainder of patients, nodular. Comparison of patients with leukemic phase of MCL with CSIV (BM), has shown significantly higher expression of CD19, CD20, and CD23, followed by permanently negative expression of CD23. Patients with blastic variant of MCL had higher expression of CD23, compared to typical MCL (P < 0.001). Median OS was 20 months, and there were no significant OS-differences between CS IV and leukemic phase patients. Survival analyses showed that negative prognostic influence had high IPI (P < 0.01), presence of extranodal localization (P < 0.01), and diffuse type of BM involvement (P < 0.01). Using Cox regression according to OS, IPI had independent prognostic value (P < 0.001). Our results demonstrated that in the advanced MCL patients the most powerful prognostic factor was IPI, while extranodal localization and type of BM infiltration were of a limited value.

Inhibition of AChE by single and simultaneous exposure to malathion and its degradation products.

In vitro inhibition of bovine erythrocytes acetylcholinesterase (AchE) by separate and simultaneous exposure to organophosphorous insecticide malathion and the transformation products, which are generally formed during the storage or natural as well as photochemical degradation pathways of malathion, was investigated. The increasing concentration of malathion, its oxidation product - malaoxon and isomerisation product - isomalathion inhibited AChE activity in a concentration-dependent manner. The half-maximum inhibitory concentrations (IC(50) values): (3.2 +/- 0.1) x 10(-5) mol/l, (4.7 +/- 0.8) x 10(-7) mol/l and (6.0 +/- 0.5) x 10(-7)mol/l were obtained from the inhibition curves induced by malathion, malaoxon and isomalathion, respectively. However, the products formed due to photoinduced degradation, phosphorodithioic O,O,S-trimethyl phosphorodithioic ester (OOS(S)) and O,O-dimethyl thiophosphate did not noticeably affect the enzyme activity at all investigated concentrations, while diethyl maleate inhibited the AChE activity at concentrations >10 mmol/l. By simultaneous exposure of the enzyme to malaoxon and isomalathion in various concentration combinations the additive effect was achieved by low concentration of inhibitors, while the antagonistic effect was obtained at high concentration (>or= 3 x 10(-7) mol/l) of inhibitors. Inhibitory power of irradiated samples of 1 +/- 10(-5) mol/l malathion can be attributed to the formation of malaoxon and isomalathion, organophosphates about 100 times more toxic than their parent compound, while the presence of non-inhibiting degradation product OOS(S) did not affect the inhibitor efficiency of inhibiting malathion by-products, malaoxon and isomalathion.

Malignant histiocytosis with central nervous system involvement and hepatic mucinous cystadenoma in a single patient with review of the literature.

Malignant histiocytosis is a rare neoplasm of the reticuloendothelial system characterized by neoplastic proliferation of tissue histiocytes. We report a case of malignant histiocytosis in a 64-year-old female initially operated on for a mucinous cystadenoma of her liver. Four months after the operation, skin induration on the neck and anterior thoracic wall and systemic lymphadenopathy were noted. Histology and immunohistochemistry of the lymph node and bone marrow specimens showed extensive infiltration with atypical cells, resembling malignant histiocytes (CD45, CD45RO, CD11c, CD68, lysozyme, antitrypsin and alpha1-antichymotrypsin positive; CD1, CD35, B-cell and T-cells markers negative). She was treated with vinblastine, methotrexate and dexamethasone (3 cycles) without response. The therapy was switched to CHOP (cyclophosphamide, vincristine, doxorubicin, and prednisone) with disappearance of lymphadenopathy. Bone marrow infiltration by histiocytes was reduced to 20%. Two months after completion of 8 cycles of CHOP she experienced severe headaches, vomiting, loss of consciousness, and developed paraparesis. A CT scan of the brain was normal but the cerebrospinal fluid cytology showed presence of histiocytes. The patient was then treated with intrathecal methotrexate, prednisolone and cytosine-arabinoside and systemic chemotherapy with etoposide and cyclophosphamide. Her condition improved, she became conscious, her headache diminished, she became mobile but skin and nodal lesions reappeared along with extensive marrow histiocytic infiltration. She finally died 22 months after diagnosis.

Interferon alpha sensitisation induced fatal renal insufficiency in a patient with chronic myeloid leukaemia: case report and review of literature.

Renal dysfunction as a sequel to extended interferon alfa (IFNalpha) treatment in chronic myeloid leukaemia (CML) has been reported previously in six patients. An additional patient is presented with Philadelphia chromosome positive (Ph+) CML and nephrotic syndrome in whom initial renal insufficiency developed after only one month of low dose IFNalpha therapy. The renal biopsy showed a focal segmental mononuclear cell infiltration, basal membrane thickening, and deposits of immunoglobulins (IgG; IgAGM IC3). In spite of discontinuation of IFNalpha, renal function deteriorated and the patient died six months later. This case represents an instance of fatal kidney insufficiency as an untoward effect of sensitisation to the IFNalpha, confirmed by modified Coombs assay.

Predictive value of prognostic indices in patients with follicular lymphomas.

PURPOSE: The aim of this study was to compare which of three indices--International Prognostic Index (IPI), Italian Lymphoma Intergroup (ILI) index, Follicular Lymphoma adapted International Prognostic Index (FLIPI)--is the most useful in predicting outcome in follicular lymphoma (FL) patients and to identify other clinical and laboratory prognostic factors that influence survival. PATIENTS AND METHODS: Clinical and prognostic studies were carried out in 99 patients with FL. RESULTS: The distribution of patients in IPI risk groups was 44.4%, 19.2%, and 36.4% of cases classified as low, intermediate, and high risk. According to ILI, low-, intermediate-, and high-risk scores were present in 34.3%; 27.3%, and 38.4% of FL patients. After applying the FLIPI index, the patients were divided into three risk groups: low (21.2% of cases), intermediate (39.4%), and high (39.4%) of FL patients. Survival curves demonstrated a high significant difference for the low- and high-risk group according to IPI and FLIPI (log rank=91.13 and 82.17 respectively; p < 0.0001). Difference in overall survival (OS) and failure-free survival (FFS) among low-, intermediate-, and high-risk groups according to ILI was statistically significant (log rank test p < 0.0001). CONCLUSION: All three indices are important tools for prognostic evaluation of FL patients, as well as useful in identifying FL patients with poor outcome. IPI and FLIPI classify patients into two risk groups (low/intermediate- and high-risk groups) with significance difference in OS and FFS, but ILI is more reliable in stratifying patients in low-, intermediate-, and high-risk groups.

Ki-67 proliferative marker in lymph node aspirates of patients with non-Hodgkin's lymphoma.

Proliferative activity of lymphoma cells was tested by immunocytochemical staining with Ki-67 monoclonal antibody in 63 aspirates of peripheral lymph nodes sampled from patients suffering from non-Hodgkin's lymphoma. Referring to the dominant cell population in nodal aspirates, a rising trend of Ki-67 proliferative marker was noted from the small cells (X = 13.20) and small cells with notched nucleus (X = 43.52) and large cells (X = 79.47) with histopathologic equivalents corresponding to aggressive lymphoma. Statistical testing of the difference in the Ki-67 proliferative marker against demographic and clinical-laboratory characteristics of the studied patients revealed the levels of significance for the performance status, bone marrow infiltration, and albumin serum value. Correlation of cytomorphological and immunocytochemical results was tested against International Prognostic Index (IPI). Statistically significant correlation of Ki-67 with cytomorphology and REAL-immunocytochemical classification of lymphoma was confirmed, but not with the IPI index. In order to determine the prognostic importance of Ki-67 marker, the patients were classified into those with low Ki-67 (<20% of proliferating cells), mean proliferation index Ki-67 (range 20-59%), and high proliferative index Ki-67 (positive in over 60% of lymphoma cells). Testing Ki-67 with survival we have found that the low proliferative index was associated with the longest survival, median about 36 mo; for proliferative marker values ranging between 20 and 59%, the median survival was 30.4 mo; and survival of patients with the high proliferative index was only 12.9 mo.

Evaluation of Levothyroxine Bioavailability after Oral Administration of a Fixed Combination of Soy Isoflavones in Post-menopausal Female Volunteers.

BACKGROUND: Post-menopausal women under treatment with levothyroxine for their medical conditions may take concomitantly dietary supplements containing soy isoflavones in combination to treat their post-menopausal symptoms. The aim of this study was to investigate the effect of a fixed combination of soy isoflavones on the oral bioavailability of levothyroxine in post-menopausal female volunteers. METHODS: 12 healthy post-menopausal female, who were on stable oral levothyroxine as replacement/supplementation therapy for hypothyroidism, received a single recommended oral dose of a food supplement containing 60 mg of soy isoflavones (>19% genistin and daidzin) concomitantly with (test) and 6 h later (reference) the administration of levothyroxine in a randomized, open label, crossover fashion. Plasma concentrations of levothyroxine and soy isoflavones (daidzin, daidzein, genistin, genistein, S-equol) were determined by LC-MS/MS. Pharmacokinetic (PK) parameters were determined by non-compartmental analysis. No effect of soy isoflavones was assumed if the 90% confidence intervals (CIs) for the estimated ratio test/reference was included in the acceptance limits 0.80-1.25 for PK parameters Cmax and AUCt. RESULTS: The test/reference ratios Cmax and AUCt of levothyroxine were very close to unity (1.02 and 0.99, respectively) and the corresponding 90% CIs (0.99-1.04 and 0.88-1.12, respectively) fell entirely within the acceptance bioequivalence limits. CONCLUSION: The combination of soy isoflavones used in the present investigation does not affect the rate and extent of levothyroxine absorption when administered concomitantly in post-menopausal women.

Incidence and role of apoptosis in myelodysplastic syndrome: morphological and ultrastructural assessment.

By application of morphological and ultrastructural methods for identification of apoptosis, we analyzed the incidence of morphologically evident apoptosis in the bone marrow of 30 patients with myelodysplastic syndrome (MDS), and in the bone marrow of 12 healthy individuals. According to FAB classification, out of 30 patients, eight (26.6%) had refractory anemia, three (10%) had refractory anemia with ringed sideroblasts, 14 (46.6%) had refractory anemia with excess of blasts and two (6.8%) had refractory anemia with excess of blasts in transformation. Three patients (10%) had chronic myelomonocytic leukemia. Cells in apoptosis were examined on semithin slides and expressed as the apoptotic index (AI) (percent counted on at least 1000 cells). An overall increase in apoptosis in patients with MDS was found (median AI in patients vs controls, 3.13% vs 1.05%, P < 0.01 by Mann-Whitney U test). Also, negative correlation between AI and white blood cell count was found (linear r= -0.53, or Spearman rank R= -0.52, both P < 0.01). In patients with evident karyotype changes AI was not higher than in patients with normal karyotype. This suggests that discrete alterations in apoptosis are present even in karyotypically 'normal' clones. Our results strongly support the hypothesis that apoptosis has a role in ineffective hematopoiesis and may be a mechanism responsible for the paradox of hypercellular bone marrow and peripheral blood pancytopenia in MDS.

The effect of subchronic supplementation with folic acid on homocysteine induced seizures.

Influence of folic acid on the CNS is still unclear. Folate has a neuroprotective effect, while on the other hand excess folate can exacerbate seizures in epileptics. The aim of the present study was to examine the effect of subchronic administration of folic acid on behavioural and electroencephalographic (EEG) characteristics of DL homocysteine thiolactone induced seizures in adult rats. The activity of Na⁺/K⁺-ATPase and Mg²âº-ATPase in different brain regions was investigated. Adult male Wistar rats were divided into groups: 1. Controls (C, 0.9% NaCl); 2. DL homocysteine-thiolactone 8.0 mmol/kg (H); 3. Subchronic supplementation with folic acid 5 mg/kg for 7 days (F) and 4. Subchronic supplementation with F + single dose of H (FH). Seizure behaviour was assessed by incidence, latency, number and intensity of seizure episodes. Seizure severity was described by a descriptive scale with grades 0-4. For EEG recordings, three gold-plated recording electrodes were implanted into the skull. Subchronic supplementation with folic acid did not affect seizure incidence, median number of seizure episodes and severity in FH, comparison with H (p > 0.05). The majority of seizure episodes in all groups were of grade 2. There were no significant differences in lethal outcomes at 24 h upon H injection in the FH vs. H group. The activity of Na⁺/K⁺-ATPase and Mg²âº-ATPase was significantly increased in almost all examined structures in the FH vs. H group. Subchronic folic acid administration did not exacerbate H induced seizures and completely recovered the activity of ATPases.

Effects of chronic treatment with escitalopram or citalopram on extracellular 5-HT in the prefrontal cortex of rats: role of 5-HT1A receptors.

1 Microdialysis was used to study the acute and chronic effects of escitalopram (S-citalopram; ESCIT) and chronic citalopram (CIT), together with the 5-HT1A receptor antagonist WAY100,635 (N-[2-[methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexane carboxamide trihydrochloride) and the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), on extracellular 5-hydroxytryptamine (5-HT) levels in the rat prefrontal cortex. 2 Extracellular 5-HT rose to 234 and 298% of basal values after subcutaneous (s.c.) acute doses of 0.15 and 0.63 mg kg(-1) ESCIT. No further increase was observed at 2.5 mg kg(-1) ESCIT (290%). 3 The effect of 13-day s.c. infusion of 10 mg kg(-1) day(-1) ESCIT on extracellular 5-HT (422% of baseline) was greater than after 2 days (257% of baseline), whereas exposure to ESCIT was similar. In contrast, the increase in extracellular 5-HT induced by the infusion of CIT for 2 (306%) and 13 days (302%) was similar. However, brain and plasma levels of S-citalopram in rats infused with CIT for 13 days were lower than after 2 days. 4 Acute treatment with 2.5 mg kg(-1) ESCIT or 5 mg kg(-1) CIT raised extracellular 5-HT by 243 and 276%, respectively, in rats given chronic vehicle but had no effect in rats given ESCIT (10 mg kg(-1) day(-1)) or CIT (20 mg kg(-1) day(-1)) for 2 or 13 days, suggesting that the infused doses had maximally increased extracellular 5-HT. WAY100,635 (0.1 mg kg(-1) s.c.) increased extracellular 5-HT levels by 168, 174 and 169% of prechallenge values in rats infused with vehicle or ESCIT for 2 or 13 days, respectively. WAY100,635 enhanced extracellular 5-HT levels to 226, 153 and 164% of prechallenge values in rats infused with vehicle or CIT for 2 and 13 days, respectively. 5 8-OH-DPAT (0.025 mg kg(-1)) reduced extracellular 5-HT by 54% in control rats, but had no effect in those given ESCIT and CIT for 13 days. 6 This series of experiments led to the conclusion that chronic treatment with ESCIT desensitizes the 5-HT1A receptors, regulating the release of 5-HT in the prefrontal cortex and enhances the effect of the drug on extracellular 5-HT. They also indicate that chronic treatment with ESCIT and CIT did not prevent WAY100,635 from raising extracellular 5-HT.