Glutamate receptors in striatum and substantia nigra: Effects of medial forebrain bundle lesions

We examined NMDA-sensitive [³H]glutamate, [³H]AMPA, [³H]kainate and metabotropic-sensitive [³H]glutamate binding sites in neostriatum and substantia nigra pars reticulata (SNr) in rats after unilateral 6-hydroxydopamine lesions of the medial forebrain bundle. One week after the lesion, NMDA, AMPA, kainate and metabotropic receptors were decreased in the ipsilateral neostriatum, whereas at three months NMDA receptors were increased while AMPA, kainate and metabotropic receptors were not changed. In the SNr at one week, only AMPA and metabotropic receptors were significantly decreased whereas three months after the lesion NMDA, AMPA and kainate binding sites were decreased. The early decrease of excitatory amino acid receptors in the striatum is likely to reflect degeneration of dopaminergic fibers, suggesting that specific subpopulations of excitatory amino acid binding sites are located on dopaminergic terminals.     

Muscarinic suppression of the evoked N-wave by oxotremorine-M recorded in the guinea-pig olfactory cortex slice

The effect of the muscarinic agonist oxotremorine-M has been studied on the surface-negative field potential (N-wave) evoked by orthodromic stimulation of the lateral olfactory tract in slices of guinea-pig olfactory cortex. Bath-application of oxotremorine-M (5-80 microM) or carbachol (10-300 microM) produced a reversible depression of the N-wave amplitude without affecting the lateral olfactory tract compound action potential. Oxotremorine-M was approximately 5 times more potent than carbachol in this respect, and the effects of both agonists were competitively blocked by telenzepine (5-100 nM), a selective M1-receptor antagonist. In contrast, methoctramine or AF-DX 116, two 'cardioselective' M2-receptor antagonists, had little or no blocking effect on the agonist responses. It is suggested that oxotremorine-M (like carbachol) inhibits the evoked field potential by activating presynaptic M1-type muscarinic receptors in the olfactory cortex slice.     

Plasminogen activator system modulates invasivecapacity and proliferation in prostatic tumor cells

The malignant phenotype of prostatic tumor cells correlates with the expression of both uPA and itscell-membrane receptor (uPAR); however, there is little information concerning the role of cell-bound uPAin matrix degradation and invasion. Our results suggest that cell-associated uPA plays a key role in regulat-ingthe amount of plasmin present at the surface of prostatic carcinoma (PRCA) cells and show that differ-entialproduction of uPA corresponds with the capacity to bind and activate plasminogen. In addition, weprovide direct evidence that both uPA secretion and the presence of uPA-uPAR complexes characterize theinvasive phenotype of PRCA cells and suggest the existence of several pathways by which tumor cells acquireplasmin activity. LNCaP cells (which do not produce uPA but express uPAR) may activate plasmin throughexogenous uPA. In vivo, the source of uPA may be infiltrating macrophages and/or fibroblasts as observedin several other systems. PAI-1 accumulation in the conditioned medium (CM) limits plasmin action to thepericellular microenvironment. Our results indicate that MMP-9 and MMP-2 are also activated by plasmingenerated by cell-bound but not by soluble, extracellular uPA. Plasmin activation and triggering of the pro-teolyticcascade involved in Matrigel invasion is blocked by antibodies against uPA (especially by anti- A-chainof uPA which interacts with uPAR) and by PA inhibitors such as p-aminobenzamidine which mayregulate levels of cell-bound uPA. uPA may also regulate growth in PRCA cells. Indeed, antibodies againstuPA A-chain (and also p-aminobenzamidine treatment) interfere with the ATF domain and inhibit cell growthin uPA-producing PC3 and DU145 prostate cancer cell lines, whereas exogenous uPA (HMW-uPA with ATF)induces growth of LNCaP prostate tumor cell line. These data support the hypothesis that in prostatic can-cerpatients at risk of progression, uPA/plasmin blockade may be of therapeutic value by blocking both growthof the primary tumor and dissemination of metastatic cells. ©Kluwer Academic Publishers     

Production of seizures and brain damage in rats by alpha-dendrotoxin, a selective K+ channel blocker.

alpha-Dendrotoxin (Dtx), a snake polypeptide, increases neuronal excitability by blocking certain fast-activating, voltage-dependent K+ channels. Thus, the behavioural, electrocortical (ECoG) and neuropathological effects of Dtx, injected into rat brain areas, were studied. A unilateral injection of 35 pmol of Dtx into the CA1 hippocampal area or the dendate gyrus (DG; upper blade) immediately produced motor and ECoG seizures, followed at 24 h by multi-focal brain damage and significant neuronal loss. Whilst brain damage was seen bilaterally, significant neuronal loss occurred only in regions (CA1, CA3, CA4 and DG) ipsilateral to the site of injection. A lower dose (3.5 pmol) of toxin elicited motor and ECoG seizures but failed to produce brain damage. Seizures were observed 50 min after injecting Dtx (35 pmol) into the amygdala, though significant neuronal loss was not evident. 4-Aminopyridine (100 nmol), given into the CA1 area elicited a similar motor and ECoG pattern to that of Dtx except no brain damage could be seen at 24 h. Systemic pretreatment with antagonists of N-methyl-D-aspartate receptors (MK-801 or CGP 37849) did not protect against the effects typically evoked by injecting Dtx into the CA1 area.     

Associations of Dietary Patterns with Incident Depression: The Maastricht Study

Our aim was to assess the association between a priori defined dietary patterns and incident depressive symptoms. We used data from The Maastricht Study, a population-based cohort study (n = 2646, mean (SD) age 59.9 (8.0) years, 49.5% women; 15,188 person-years of follow-up). Level of adherence to the Dutch Healthy Diet (DHD), Mediterranean Diet, and Dietary Approaches To Stop Hypertension (DASH) were derived from a validated Food Frequency Questionnaire. Depressive symptoms were assessed at baseline and annually over seven-year-follow-up (using the 9-item Patient Health Questionnaire). We used Cox proportional hazards regression analyses to assess the association between dietary patterns and depressive symptoms. One standard deviation (SD) higher adherence in the DHD and DASH was associated with a lower hazard ratio (HR) of depressive symptoms with HRs (95%CI) of 0.78 (0.69–0.89) and 0.87 (0.77–0.98), respectively, after adjustment for sociodemographic and cardiovascular risk factors. After further adjustment for lifestyle factors, the HR per one SD higher DHD was 0.83 (0.73–0.96), whereas adherence to Mediterranean and DASH diets was not associated with incident depressive symptoms. Higher adherence to the DHD lowered risk of incident depressive symptoms. Adherence to healthy diet could be an effective non-pharmacological preventive measure to reduce the incidence of depression.     

Glycosidic intermediates identified in 1H MR spectra of intact tumour cells may contribute to the clarification of aspects of glycosylation pathways

The glycosylation process, through the addition of carbohydrates, is a major post‐translational modification of proteins and glycolipids. Proteins may be glycosylated in either the secretory pathway leading to N‐linked or O‐linked glycoproteins or as nucleocytoplasmic glycosylation that targets only single proteins involving a single β‐linked N‐acetylglucosamine. In both cases, the key precursors are the uridine diphospho‐N‐acetylhexosamines synthesised by the hexosamine biosynthetic pathway. Furthermore, uridine diphospho‐N‐acetylglucosamine participates in the biosynthesis of sialic acid. In this work, we propose MRS for the detection of uridine diphospho‐N‐acetylhexosamines visible in high‐resolution MR spectra of intact cells from different human tumours. Signals from the nucleotide and amino sugar moieties, including amide signals observed for the first time in whole cells, are assigned, also taking advantage of spectral changes that follow cell treatment with ammonium chloride. Finally, parallel changes in uridine diphospho‐N‐acetylhexosamines and glutamine pools, observed after pH changes induced by ammonium chloride in the different tumour cell lines, may provide more details on the glycosylation processes. Copyright © 2010 John Wiley & Sons, Ltd.     

The effect of voluntary termination of pregnancy on female sexual and emotional well-being in different age groups

Introduction: To evaluate the impact of voluntary termination of pregnancy (VTOP) on the psycho-sexological well-being of females before/six months after the abortion.

Methods: A sample of 194 women was recruited from three obstetrics and gynaecological divisions. The women were evaluated for the variables “sexual functioning” with the Female Sexual Function Index (FSFI), “depression” with the Beck Depression Inventory (BDI-II), and “anxiety state” with the Self-Rating Anxiety Scale (SAS) at time 0 (the beginning of the abortion procedure) and time 1 (six months after the abortion). Since 24 women refused to fill out the questionnaires, the final sample was composed of 170 women.

Results: The women showed a slight although significant improvement in the mean FSFI score from time 0 (16.7?±?12.9) to time 1 (20.9?±?13.8) (p?p?=?0.0241). The sub-group of younger women (18–25) showed a lesser increase in FSFI score from time 0 to time 1. In addition, both depression (p?=?0.048) and anxiety (p?Discussion: Voluntary TOP may influence the sexuality of younger females differently from how it influences that of older women. Hence, the sexuality of younger female should be regularly supervised in follow-up examinations.     

Refining the Baveno VI elastography criteria for the definition of compensated advanced chronic liver disease

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