Metabolic transformation plays a primary role in the psychostimulant-like discriminative-stimulus effects of selegiline [(R)-(-)-deprenyl

l-Deprenyl [selegiline, (R)-(-)-deprenyl] is a selective inhibitor of monoamine oxidase B (MAO-B) used in the treatment of Parkinson's disease and proposed as an antidepressant and an aid for cigarette-smoking cessation and treatment of psychostimulant abuse. Beneficial therapeutic effects of (R)-(-)-deprenyl may also result from indirect actions. Brain levels of dopamine and beta-phenylethylamine (beta-PEA), a behaviorally active endogenous trace amine, increase after (R)-(-)-deprenyl treatment due to MAO-B blockade and (R)-(-)-deprenyl is metabolized to (R)-(-)-methamphetamine and (R)-(-)-amphetamine, suggesting that (R)-(-)-deprenyl may have psychostimulant-like behavioral effects. Indeed, (R)-(-)-deprenyl produces psychostimulant-like discriminative-stimulus effects in experimental animals. Here, we tested the hypothesis that psychostimulant-like behavioral effects of (R)-(-)-deprenyl are mainly mediated by its metabolites. Male Fisher F344 rats were trained to discriminate i.p. injection of 1.0 mg/kg (S)-(+)-methamphetamine or 10.0 mg/kg cocaine from injection of saline using two-lever choice schedules of food delivery or stimulus shock termination. When (R)-(-)-deprenyl was tested by substitution, it had (S)-(+)-methamphetamine- and cocaine-like discriminative-stimulus effects, but only at doses of 10 to 30 mg/kg, doses 10 to 20 times higher than those selective for MAO-B inhibition. Ro 16-6491 [N-(2-aminoethyl)-4-chlorobenzamide hydrochloride], a selective inhibitor of MAO-B enzyme activity without psychoactive metabolites, had no psychostimulant-like discriminative effects. In addition, blockade of (R)-(-)-deprenyl's metabolism with SKF 525A (beta-DEAE-diphenylpropylacetate hydrochloride; 50 mg/kg i.p.) reduced or eliminated (R)-(-)-deprenyl's psychostimulant-like discriminative effects. When beta-PEA synthesis was blocked by NSD 1015 (m-hydroxy-benzyl-hydrazine; 30 mg/kg i.p.), there was a modest reversal of (R)-(-)-deprenyl's psychostimulant-like discriminative effects under some conditions, indicating a facilitatory modulation of the psychostimulant-like discriminative effects of (R)-(-)-deprenyl metabolites by elevated levels of beta-PEA under certain conditions.     

Pegylated interferon-alpha plus taurine in treatment of rat liver fibrosis

AIM: To investigate the antif ibrotic effects of peginterferon- alpha 2b and taurine on oxidative stress markers and hepatocellular apoptosis. METHODS: Sixty rats with CCl4-induced liver fibrosis were divided into 4 groups (n = 15). Group 1 was left for spontaneous recovery (SR). Groups 2-4 received peginterferon-alpha 2b, taurine, and their combination, respectively, for four weeks. Histological f ibrosis scores, histomorphometric analysis, tissue hydroxyproline, tissue MDA, GPx and SOD activities were determined. Activated stellate cells and hepatocellular apoptosis were also evaluated. RESULTS: The degree of f ibrosis decreased in all treatment groups compared to spontaneous recovery group. Taurine alone and in combination with peginterferon-alpha 2b reduced oxidative stress markers, but peginterferon-alpha 2b alone did not. Apoptotic hepatocytes and activated stellate cells were higher in groups 2-4 than in group 1. Combined taurine and peginterferon-alpha 2b further reduced fibrosis and increased activated stellate cell apoptosis, but could not improve oxidative stress more than taurine alone.CONCLUSION: Peginterferon-alpha 2b exerts anti- f ibrotic effects on rat liver fibrosis. It seems ineffective against oxidative stress in vivo. Peginterferon-alpha 2b in combination with taurine seems to be an antif ibrotic strategy.     

Differential modulation of a 40 kDa catecholamine regulated protein in the core and shell subcompartments of the nucleus accumbens following chronic quinpirole and haloperidol administration in the rat

Past reports have shown dopamine (DA) D2/D3 receptor agonist quinpirole (QNP) and the DA D2 receptor antagonist, haloperidol (HAL) display a significant increase in expression of catecholamine regulated protein (CRP40) in the nucleus accumbens (NAcc) and the striatum, respectively. The present study investigated the in vivo effects of QNP and HAL on CRP40 protein levels within the core and shell subcompartments of the NAcc. As significant homology exists between CRP40 and Hsp70/Hsc70, parallel studies with inducible Hsp70 and constitutive Hsc70 were conducted to establish the specificity with respect to QNP on Hsp70 and CRP40. Results demonstrated that CRP40 protein was significantly expressed in the shell relative to the core region of NAcc following chronic QNP (+16.28%+/-0.42%, P<0.05) and CRP40 protein was significantly expressed in the core vs. the shell following chronic HAL (+36.02%+/-0.75%, P<0.05). There was no significant change in Hsp70 protein levels following chronic QNP or HAL administration. The results demonstrated selective modulation of CRP40 within NAcc by QNP and HAL treatment, without affecting Hsp70.     

The eye lens chaperone α-crystallin forms defined globular assemblies

α-Crystallins are molecular chaperones that protect vertebrate eye lens proteins from detrimental protein aggregation. αB-Crystallin, 1 of the 2 α-crystallin isoforms, is also associated with myopathies and neuropathological diseases. Despite the importance of α-crystallins in protein homeostasis, only little is known about their quaternary structures because of their seemingly polydisperse nature. Here, we analyzed the structures of recombinant α-crystallins using biophysical methods. In contrast to previous reports, we show that αB-crystallin assembles into defined oligomers consisting of 24 subunits. The 3-dimensional (3D) reconstruction of αB-crystallin by electron microscopy reveals a sphere-like structure with large openings to the interior of the protein. αA-Crystallin forms, in addition to complexes of 24 subunits, also smaller oligomers and large clusters consisting of individual oligomers. This propensity might explain the previously reported polydisperse nature of α-crystallin.     

Novel TSHR mutations in consanguineous families with congenital nongoitrous hypothyroidism

Objective Nonsyndromic autosomal recessively inherited nongoitrous congenital hypothyroidism (CHNG) can be caused by mutations in TSHR, PAX8, TSHB and NKX2‐5. We aimed to investigate mutational frequencies of these genes and genotype/phenotype correlations in consanguineous families with CHNG. Design Because consanguinity in individuals with a presumptive genetic condition is often an indicator of an autosomal recessive inheritance and allows firmer correlations to be established between genotype and phenotype, we planned to execute our study in consanguineous families. Patients Hundred and thirty‐nine children with CHNG phenotype born to consanguineous families. Measurements First, we investigated cases for evidence of linkage to the four known CHNG genes by microsatellite marker analysis. Mutation analysis by direct sequencing was then performed in those cases in whom linkage to the relevant candidate gene could not be excluded. In addition, in silico analysis of the predicted structural effects of TSHR mutations was performed and related to the mutation‐specific disease phenotype. Results Homozygous germline TSHR mutations were detected in six families (5%), but no mutations were detected in PAX8, TSHB and NKX2‐5. Four of TSHR mutations had not previously been described. Genotype–phenotype correlations were established and found to be related to the predicted structural effects of the mutations. Conclusions Known causative genes account for the development of CHNG only in a minority of cases, and our cohort should provide a powerful resource to identify novel causative genes and to delineate the extent of locus heterogeneity in autosomal recessively inherited CHNG.     

DNA analysis as a tool for breast cancer malpractice determination: an interdisciplinary approach

Malpractice in breast cancer can be seen as false-negative or false-positive findings which may result in either late or incorrect therapies. Biopsy material can be unintentionally interchanged, leading to incorrect treatment, and psychological damage to the patient. There is an obvious need for individualization of the tissue samples in such cases. In this study we used a multidisciplinary approach to integrate DNA technology that has been standardized and used in forensic science for other purposes, mainly to prove malpractice that has been the result of interchanging tissue samples in breast cancer. The main focus of the study was to evaluate the applicability of the technique, therefore we studied the samples of a 58-year-old female for whom the result of pathological analysis was reported as 'invasive ductal carcinoma'. The patient was surgically treated by a modified mastectomy technique and referred for chemotherapy. Prior to chemotherapy we found that the tissue samples analyzed did not belong to the patient in question. We used a battery of 15 polymorphic STR loci to identify the sample and we had strong evidence for exclusion of the patient. The analysis was done on both blood and buccal swab of the patient and on the tissue sample. We concluded that the technique is applicable and useful; however care should be taken in the interpretation of the results because the mutations in the tumoral tissues are very well known. Therefore, the maximum of informative loci should be studied and loss of heterozygosity should always be considered. We should also have in mind the possibility of intentional interchange which gives the results value in medico-legal investigations.     

Ewing's sarcoma of the axial system in patients older than 15 years: dismal prognosis despite intensive multiagent chemotherapy and aggressive local treatment

BACKGROUND: Older age and axial location of Ewing's sarcoma have been reported as unfavorable prognostic factors. METHODS: The records of patients older than 15 years with the Ewing's family of tumors were reviewed retrospectively. After the induction chemotherapy consisting of alternating vincristine, adriablastin, cyclophosphamide (VAC) and etoposide, ifosfamide with mesna protection (IE), a local treatment modality was chosen based on tumor and patient characteristics. RESULTS: Twenty-five patients with a median age of 19 years were evaluated. Median follow-up was 26 months (range 4-58). Seventeen patients (68%) had died. In univariate analysis, factors predictive of shorter survival were the patients presenting with metastatic disease, with the primary tumor located at the pelvis, those who never achieved complete response to chemotherapy and those who had chemotherapy for <12 months. Only a negative link with pelvic location was observed in multivariate analysis [risk ratio 7.5; 95% confidence interval (CI) 1.52-37.06; P = 0.0134]. Median progression-free survival (PFS) and overall survival (OS) were 10 months (95% CI 6.2-13.8) and 14 months (95% CI 9.3-18.7), respectively. Cumulative 2-year PFS and OS were 19.0% (95% CI, SD +/-8.4) and 32.7% (95% CI, SD +/-9.8), respectively. CONCLUSIONS: The prognosis of patients with axial Ewing's sarcoma is dismal despite an intensive, multimodality approach including multiagent, alternating chemotherapy, surgery and/or radiotherapy. A more aggressive approach should be considered for this group of Ewing's sarcoma patients.     

Protective effects of erythropoietin against ethanol-induced apoptotic neurodegenaration and oxidative stress in the developing C57BL/6 mouse brain

The developing central nervous system is extremely sensitive to ethanol, with well-defined temporal periods of vulnerability. Recent studies have shown that administration of ethanol to infant rats during the synaptogenesis period triggers extensive apoptotic neurodegeneration throughout many regions of the developing brain. Furthermore, acute ethanol administration produces lipid peroxidation in the brain as an indicator of oxidative stress. In recent years, it has been shown that erythropoietin (EPO) has a critical role in the development, maintenance, protection, and repair of the nervous system. In the present study, we investigated the effect of EPO against ethanol-induced neurodegeneration and oxidative stress in the developing C57BL/6 mouse brain. Seven-day-old C57BL/6 mice were divided into three groups: control group, saline-treated group, EPO-treated group. Ethanol was administered to mice at a dosage of 2.5 g/kg for two times with a 2-h interval. Recombinant human EPO (rhEPO) was given 1000 U/kg. Twenty-four hours after the first dose of ethanol, all the animals were killed. Neuronal cell death, apoptosis, thiobarbituric acid substance (TBARS) levels, superoxide dismutase (SOD), and glutathione peroxidase (Gpx) enzymes activities were evaluated. Histopathological evaluation demonstrated that EPO significantly diminished apoptosis in the cerebellum, prefrontal cortex, and hippocampus and also spared hippocampal CA1, CA2, and CA3 neurons. Simultaneous administration of EPO along with ethanol attenuated the lipid peroxidation process and restored the levels of antioxidants. Regarding the wide use of erythropoietin in premature newborns, this agent may be potentially beneficial in treating ethanol-induced brain injury in the perinatal period.