Long-lasting effects of chronic chlorimipramine treatment of rats on exploratory activity on a hole-board, and on immobility in the forced swimming test

The study concerned the effects of acute and chronic clomipramine administration to male rats on exploratory activity in a novel environment (hole-board) and on immobility in the forced swimming test. Acute clomipramine administration did not alter either exploratory activity on a hole-board as measured 3 or 20 h after drug administration, or immobility in the forced swimming test as measured 20 h after drug administration. Approximately 20 h after the last injection of clomipramine, the rats chronically treated with the drug showed reduced exploratory activity on the hole-board. In contrast, chronic clomipramine treatment significantly increased the activity in the forced swimming test. The effects of the drug on exploratory and forced swimming activities persisted for 14 days after the cessation of clomipramine administration. These data indicate that chronic clomipramine administration exerted profound and long-lasting effects on central nervous system function. The long-lasting action of the drug on behaviour in the forced swimming test might explain the long-term beneficial effect of antidepressant drugs in counteracting behavioral depression.     

Exercise-induced metallothionein expression in human skeletal muscle fibres

Exercise induces free oxygen radicals that cause oxidative stress, and metallothioneins (MTs) are increased in states of oxidative stress and possess anti-apoptotic effects. We therefore studied expression of the antioxidant factors metallothionein I and II (MT-I + II) in muscle biopsies obtained in response to 3 h of bicycle exercise performed by healthy men and in resting controls. Both MT-I + II proteins and MT-II mRNA expression increased significantly in both type I and II muscle fibres after exercise. Moreover, 24 h after exercise the levels of MT-II mRNA and MT-I + II proteins were still highly increased and the MT-II mRNA expression reached a 15-fold increase. As expected, immunohistochemical detection of malondialdehyde (MDA) and nitrotyrosine (NITT) showed that formation of free radicals and oxidative stress were clearly increased in exercising muscle peaking shortly after the end of exercise in both type I and II muscle fibres. This is the first report demonstrating that MT-I + II are significantly induced in human skeletal muscle fibres following exercise. As MT-I + II are antioxidant factors that protect various tissues during pathological conditions, the MT-I + II increases post exercise may represent a mechanism whereby contracting muscle fibres are protected against cellular stress and injury.     

Drosophila dSAP18 is a nuclear protein that associates with chromosomes and the nuclear matrix, and interacts with pinin, a protein factor involved in RNA splicing

SAP18 is a highly conserved protein that was proposed to be involved in multiple cellular processes from autophagy to gene regulation and mRNA processing. In this paper we show that, in Drosophila, dSAP18 is a predominantly nuclear protein that associates to both chromosomes and the nuclear matrix. dSAP18 becomes nuclear early during development, at the onset of cellularization, and remains so all through embryo development. dSAP18 is also nuclear in salivary glands, ovaries and cultured S2 cells. Here we also show that dSAP18 forms a complex with the Drosophila homolog of pinin (dPnn), a protein factor involved in mRNA splicing. dSAP18-dPnn interaction was confirmed in vivo, through co-immunoprecipitation experiments, as well as in vitro, through GST pull-down assays. These results are discussed in the context of the possible functions played by SAP18.     

Blood and Marrow Transplant Clinical Trials Network State of the Science Symposium 2007.

Outcomes of hematopoietic cell transplantation are steadily improving. New techniques have reduced transplant toxicities, and there are new sources of hematopoietic stem cells from unrelated donors. In June 2007 the Blood and Marrow Transplant Clinical Trials Network convened a State of the Science Symposium of more than 200 participants in Ann Arbor to identify the most compelling clinical research opportunities in the field. This report summarizes the symposium's discussions and identifies eleven high priority clinical trials that the network plans to pursue over the course of the next several years.     

Metallothionein (MT)-III: generation of polyclonal antibodies, comparison with MT-I+II in the freeze lesioned rat brain and in a bioassay with astrocytes, and analysis of Alzheimer's disease brains

Metallothionein-III is a low molecular weight, heavy-metal binding protein expressed mainly in the central nervous system. First identified as a growth inhibitory factor (GIF) of rat cortical neurons in vitro, it has subsequently been shown to be a member of the metallothionein (MT) gene family and renamed as MT-III. In this study we have raised polyclonal antibodies in rabbits against recombinant rat MT-III (rMT-III). The sera obtained reacted specifically against recombinant zinc-and cadmium-saturated rMT-III, and did not cross-react with native rat MT-I and MT-II purified from the liver of zinc injected rats. The specificity of the antibody was also demonstrated in immunocytochemical studies by the elimination of the immunostaining by preincubation of the antibody with brain (but not liver) extracts, and by the results obtained in MT-III null mice. The antibody was used to characterize the putative differences between the rat brain MT isoforms, namely MT-I+II and MT-III, in the freeze lesion model of brain damage, and for developing an ELISA for MT-III suitable for brain samples. In the normal rat brain, MT-III was mostly present primarily in astrocytes. However, lectin staining indicated that MT-III immunoreactivity was also present in microglia, monocytes and/or macrophages in the leptomeninges and lying adjacent to major vessels. In freeze lesioned rats, both MT-I+II and MT-III immunoreactivities increased in the ipsilateral cortex. The pattern of MT-III immunoreactivity significantly differed from that of MT-I+II, since the latter was evident in both the vicinity of the lesioned tissue and deeper cortical layers, whereas that of the former was located only in the deeper cortical layers. This suggests different roles for these MT isoforms, and indeed in a new bioassay measuring astrocyte migration in vitro, rMT-III promoted migration to a higher extent than MT-I+II. Thus, MT-III could not only affect neuronal sprouting as previously suggested, but also astrocyte function. Finally, MT-III protein levels of patients with Alzheimer's disease (AD) were, if anything, increased when compared with similarly aged control brains, which was in agreement with the significantly increased MT-III mRNA levels of AD brains.     

Factor-XII congenital deficiency. A new family study

This report describes two people in a family with Hageman trait (homozygotes) (Factor XII = 0.06%). In addition eight family members were studied to evaluate the inheritance of this congenital deficiency. A study of the Kallikrein-Kininogen system induced by the fragments of Factor XII was carried out. It is concluded that the inheritance is as described by Veltkamp and that the Kallikrein release from the prekallikreinogen (Fletcher factor) "in vitro" is related to the amount of Factor XII procoagulant protein.     

Inhibition of β‐amyloid toxicity by short peptides containing N‐methyl amino acids

Abstract: Single N‐methyl amino acid‐containing peptides related to the central hydrophobic region β_16–20 (Lys‐Leu‐Val‐Phe‐Phe) of the β‐amyloid protein are able to reduce the cytotoxicity of natural β_1–42 in PC12 cell cultures. N‐methyl phenylalanine analogs yield statistically significant increments in cell viability (Student's t‐test < 0.01%) and are nontoxic in the same assay. These promising results indicate that these peptide molecules could be a starting point for the development of potential therapeutic compounds for the treatment of Alzheimer's disease.     

Aberrant expression of tetraspanin molecules in B-cell chronic lymphoproliferative disorders and its correlation with normal B-cell maturation.

Tetraspanin proteins form signaling complexes between them and with other membrane proteins and modulate cell adhesion and migration properties. The surface expression of several tetraspanin antigens (CD9, CD37, CD53, CD63, and CD81), and their interacting proteins (CD19, CD21, and HLA-DR) were analyzed during normal B-cell maturation and compared to a group of 67 B-cell neoplasias. Three patterns of tetraspanin expression were identified in normal B cells. The first corresponded to bone marrow CD10(+) B-cell precursors (BCP) which showed high expression of CD81 and CD9, low reactivity for CD53 and negativity for CD37. CD10(-) B-lymphocytes showed downregulation of CD9/CD81 and upregulation of CD53/CD37. Plasma cells showed re-expressed CD9 and downregulated CD37. Hierarchical clustering analysis of flow cytometry immunophenotypic data showed a good correlation between the tumor differentiation stage and the pattern of tetraspanin expression, with all analyzed individual samples classified into three major groups, independently of their normal or neoplastic origin. Despite this, neoplastic B-cells frequently showed aberrantly high/low expression of the different markers analyzed. Interestingly, in B-cell chronic lymphocytic leukemia, abnormal expression of CD53 and CD9 were associated with different patterns of disease infiltration, which would support the role of these molecules on modulating adhesion and migration of neoplastic B cells.