Flesinoxan Dose-Dependently Reduces Extracellular 5-Hydroxytryptamine (5-HT) in Rat Median Raphe and Dorsal Hippocampus Through Activation of 5-HT1A Receptors

Abstract: The effects of systemic administration of the serotonin (5-hydroxytryptamine) 5-HT_1A receptor agonists flesinoxan and 8-hydroxy-2-(di- n -propylamino)tetralin on extracellular 5-HT were measured using microdialysis probes in both median raphe nucleus and dorsal hippocampus. Both 5-HT_1A agonists dose-dependently decreased dialysate 5-HT levels from both brain regions. The effects of flesinoxan in the median raphe (0.3 mg/kg) and dorsal hippocampus (1.0 mg/kg) could be blocked by the 5-HT_1A receptor antagonist N -[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]- N -(2-pyridyl)cyclohexane carboxamide trihydrochloride (WAY 100,635) at a dose of 0.05 mg/kg s.c. The antagonist itself had no effect at this dosage. Local perfusion of flesinoxan for 30 min through the dialysis probe into the median raphe region at concentrations of 20, 100, and 1,000 n M resulted in a significant decrease in dialysate 5-HT content from both regions. The effect of 100 n M flesinoxan could be blocked by coperfusion of 1,000 n M WAY 100,635. The data indicate that flesinoxan is a potent 5-HT_1A receptor agonist and also support the notion that somatodendritic 5-HT_1A autoreceptors regulate both terminal and somatodendritic 5-HT release.     

Seven New Mutations in hMSH2, an HNPCC Gene, Identified by Denaturing Gradient-Gel Electrophoresis

Hereditary nonpolyposis colorectal cancer (HNPCC) is a relatively common autosomal dominant cancer-susceptibility condition. The recent isolation of the DNA mismatch repair genes (hMSH2, hMLH1, hPMS1, and hPMS2) responsible for HNPCC has allowed the search for germ-line mutations in affected individuals. In this study we used denaturing gradient-gel electrophoresis to screen for mutations in the hMSH2 gene. Analysis of all the 16 exons of hMSH2, in 34 unrelated HNPCC kindreds, has revealed seven novel pathogenic germ-line mutations resulting in stop codons either directly or through frameshifts. Additionally, nucleotide substitutions giving rise to one missense, two silent, and one useful polymorphism have been identified. The proportion of families in which hMSH2 mutations were found is 21%. Although the spectrum of mutations spread at the hMSH2 gene among HNPCC patients appears extremely heterogeneous, we were not able to establish any correlation between the site of the individual mutations and the corresponding tumor spectrum. Our results indicate that, given the genomic size and organization of the hMSH2 gene and the heterogeneity of its mutation spectrum, a rapid and efficient mutation detection procedure is necessary for routine molecular diagnosis and presymptomatic detection of the disease in a clinical setup.     

Cardiac resynchronisation therapy: results from daily practice in Rijnstate Hospital, Arnhem

BackgroundCardiac resynchronisation therapy (CRT) is an effective treatment to improve the clinical outcome of selected patients with heart failure. Clinical trials have studied clinical outcome and reported clinical improvements, but clinical consequences and results in daily practice are less well known. We evaluated clinical outcome in all patients with CRT implantation in our centre. MethodsData of 119 consecutive patients who met the criteria for CRT implantation in Rijnstate Hospital, Arnhem in the period 28 November 2000 until 1 January 2006 were collected. We analysed implantation procedure, hospitalisation for heart failure or other causes, mortality and device-related events. ResultsIn total 119 patients (83 men, 36 women; mean age 69 years) were eligible for CRT. Before implantation they had received optimal pharmacological therapy. Implantation was successful in 97% of patients. Procedural-related complications were seen in eight patients. During follow-up, 22 patients (18.5%: 14 men, 8 women) died. Causes of death were heart failure (11 patients), sudden cardiac death (4 patients) and noncardiac death (7 patients). Hospitalisation occurred 81 times, of which 77 for cardiac reasons. In follow-up the estimated five-year cumulative survival was 70%. ConclusionThis retrospective study from a single centre showed a high procedural success rate, low prevalence of complications and low mortality in comparison to other studies. Despite better functional capacity, the hospitalisation rate due to heart failure was high. (Neth Heart J 2009;17:6-8.)     

Formation and Metabolism of Dopamine in Nine Areas of the Rat Brain: Modifications by Haloperidol

The rate of removal of 3,4-dihydroxyphenylacetic acid (DOPAC) in nine rat brain areas (striatum, nucleus accumbens, tuberculum olfactorium, hypothalamus, lateral hippocampus, occipital cortex, brain stem, cerebellum, and retina) was calculated from its exponential decline after monoamine oxidase inhibition by pargyline. The experiments were carried out with rats pretreated with either saline or haloperidol. It appeared that the efficiency with which DOPAC was removed from the brain (expressed by the fractional rate constant k) varied considerably throughout the brain. Haloperidol dramatically decreased the k values, and in addition these effects differed widely in the various brain areas. Similarly to DOPAC, haloperidol had a pronounced retarding effect on the efflux of homovanillic acid (HVA) from the brain. These findings strongly suggest that great care should be taken when drug-induced alterations in DOPAC and HVA concentrations are interpreted as changes in dopaminergic activity. The dopamine (DA) concentrations were measured in the same experiments, but it appeared that the pargyline-induced rise in DA was of limited use for the estimation of the synthesis rate of the amine. We calculated the rate of catecholamine synthesis in the nine brain areas from the rise of 3,4-dihydroxyphenylalanine (DOPA) during decarboxylase inhibition. In saline- as well as in haloperidol-pretreated rats it was found that the total catecholamine synthesis rate in the typical dopaminergic areas (striatum, nucleus accumbens, and tuberculum olfactorium) was of the same order of magnitude as the DOPAC rate of removal. This confirms that DOPAC formation is quantitatively the main route of degradation in these brain areas.(ABSTRACT TRUNCATED AT 250 WORDS)     

Application of enzymatic apple pomace hydrolysate to production of 2,3-butanediol by alkaliphilic <Emphasis Type="Italic">Bacillus licheniformis</Emphasis> NCIMB 8059

2,3-Butanediol (2,3-BD) synthesis by a nonpathogenic bacterium Bacillus licheniformis NCIMB 8059 from enzymatic hydrolysate of depectinized apple pomace and its blend with glucose was studied. In shake flasks, the maximum diol concentration in fed-batch fermentations was 113 g/L (in 163 h, from the hydrolysate, feedings with glucose) while in batch processes it was around 27 g/L (in 32 h, from the hydrolysate and glucose blend). Fed-batch fermentations in the 0.75 and 30 L fermenters yielded 87.71 g/L 2,3-BD in 160 h, and 72.39 g/L 2,3-BD in 94 h, respectively (from the hydrolysate and glucose blend, feedings with glucose). The hydrolysate of apple pomace, which was for the first time used for microbial 2,3-BD production is not only a source of sugars but also essential minerals.     

The fasting-induced adipose factor/angiopoietin-like protein 4 is physically associated with lipoproteins and governs plasma lipid levels and adiposity

Proteins secreted from adipose tissue are increasingly recognized to play an important role in the regulation of glucose metabolism. However, much less is known about their effect on lipid metabolism. The fasting-induced adipose factor (FIAF/angiopoietin-like protein 4/peroxisome proliferator-activated receptor gamma angiopoietin-related protein) was previously identified as a target of hypolipidemic fibrate drugs and insulin-sensitizing thiazolidinediones. Using transgenic mice that mildly overexpress FIAF in peripheral tissues we show that FIAF is an extremely powerful regulator of lipid metabolism and adiposity. FIAF overexpression caused a 50% reduction in adipose tissue weight, partly by stimulating fatty acid oxidation and uncoupling in fat. In addition, FIAF overexpression increased plasma levels of triglycerides, free fatty acids, glycerol, total cholesterol, and high density lipoprotein (HDL)-cholesterol. Functional tests indicated that FIAF overexpression severely impaired plasma triglyceride clearance but had no effect on very low density lipoprotein production. The effects of FIAF overexpression were amplified by a high fat diet, resulting in markedly elevated plasma and liver triglycerides, plasma free fatty acids, and plasma glycerol levels, and impaired glucose tolerance in FIAF transgenic mice fed a high fat diet. Remarkably, in mice the full-length form of FIAF was physically associated with HDL, whereas truncated FIAF was associated with low density lipoprotein. In human both full-length and truncated FIAF were associated with HDL. The composite data suggest that via physical association with plasma lipoproteins, FIAF acts as a powerful signal from fat and other tissues to prevent fat storage and stimulate fat mobilization. Our data indicate that disturbances in FIAF signaling might be involved in dyslipidemia.