Characterization of fibroblast-like cells from the rat olfactory bulb

The isolation and characterization of stem cells from an alternative tissue is a subject of intensive investigation. In the present study, we have focused on the characterization of fibroblastic cells in olfactory bulb tissue of the rat. To this end, 4-6 week old rats were killed and their olfactory bulb tissue was dissected out. Olfactory bulb derived fibroblast-like cells were recovered by adhesion to cell culture plastic. The plastic adherent cultivated cells were induced to differentiate along osteoblastic, adipogenic and chondrogenic lineages. Furthermore, the expression of some surface antigens was investigated. We obtained purified cells with spindle shaped morphology in primary culture, which differentiated into mesenchymal lineages. These cells expressed CD29 and CD90 (Thy1.1) surface antigens, but not CD31, CD34 and CD45. Our results indicate that fibroblast-like cells from the olfactory bulb are mesenchymal stem cells in nature. Taken together, our data suggest that olfactory bulb tissue may constitute a new source of mesenchymal stem cells and could be used for the treatment of injury.     

Antifungal activity of the local complement system in cerebral aspergillosis

Dissemination of aspergillosis into the central nervous system is associated with nearly 100% mortality. To study the reasons for the antifungal immune failure we analyzed the efficacy of cerebral complement to combat the fungus Aspergillus. Incubation of Aspergillus in non-inflammatory cerebrospinal fluid (CSF) revealed that complement levels were sufficient to obtain a deposition on the surface, but opsonization was much weaker than in serum. Consequently complement deposition from normal CSF on fungal surface stimulated a very low phagocytic activity of microglia, granulocytes, monocytes and macrophages compared to stimulation by conidia opsonized in serum. Similarly, opsonization of Aspergillus by CSF was not sufficient to induce an oxidative burst in infiltrating granulocytes, whereas conidia opsonized in serum induced a clear respiratory signal. Thus, granulocytes were capable of considerably reducing the viability of serum-opsonized Aspergillus conidia, but not of conidia opsonized in CSF. The limited efficacy of antifungal attack by cerebral complement can be partly compensated by enhanced synthesis, leading to elevated complement concentrations in CSF derived from a patient with cerebral aspergillosis. This inflammatory CSF was able to induce (i) a higher complement deposition on the Aspergillus surface than non-inflammatory CSF, (ii) an accumulation of complement activation products and (iii) an increase in phagocytic and killing activity of infiltrating granulocytes. However, levels and efficacy of the serum-derived complement were not reached. These data indicate that low local complement synthesis and activation may represent a central reason for the insufficient antifungal defense in the brain and the high mortality rate of cerebral aspergillosis.     

Sex differences in ischemic heart disease and heart failure biomarkers

Since 1984, each year, more women than men die of ischemic heart disease (IHD) and heart failure (HF), yet more men are diagnosed. Because biomarker assessment is often the first diagnostic employed in such patients, understanding biomarker differences in men vs. women may improve female morbidity and mortality rates.Some key examples of cardiac biomarker utility based on sex include contemporary use of “unisex” troponin reference intervals under-diagnosing myocardial necrosis in women; greater use of hsCRP in the setting of acute coronary syndrome (ACS) could lead to better stratification in women; and greater use of BNP with sex-specific thresholds in ACS could also lead to more timely risk stratification in women.Accurate diagnosis, appropriate risk management, and monitoring are key in the prevention and treatment of cardiovascular diseases; however, the assessment tools used must also be useful or at least assessed for utility in both sexes. In other words, going forward, we need to evaluate sex-specific reference intervals or cutoffs for laboratory tests used to assess cardiovascular disease to help close the diagnostic gap between men and women.     

Autosomal recessive mental retardation: homozygosity mapping identifies 27 single linkage intervals, at least 14 novel loci and several mutation hotspots

Mental retardation (MR) has a worldwide prevalence of around 2% and is a frequent cause of severe disability. Significant excess of MR in the progeny of consanguineous matings as well as functional considerations suggest that autosomal recessive forms of MR (ARMR) must be relatively common. To shed more light on the causes of autosomal recessive MR (ARMR), we have set out in 2003 to perform systematic clinical studies and autozygosity mapping in large consanguineous Iranian families with non-syndromic ARMR (NS-ARMR). As previously reported (Najmabadi et al. in Hum Genet 121:43-48, 2007), this led us to the identification of 12 novel ARMR loci, 8 of which had a significant LOD score (OMIM: MRT5-12). In the meantime, we and others have found causative gene defects in two of these intervals. Moreover, as reported here, tripling the size of our cohort has enabled us to identify 27 additional unrelated families with NS-ARMR and single-linkage intervals; 14 of these define novel loci for non-syndromic ARMR. Altogether, 13 out of 39 single linkage intervals observed in our cohort were found to cluster at 6 different loci on chromosomes, i.e., 1p34, 4q27, 5p15, 9q34, 11p11-q13 and 19q13, respectively. Five of these clusters consist of two significantly overlapping linkage intervals, and on chr 1p34, three single linkage intervals coincide, including the previously described MRT12 locus. The probability for this distribution to be due to chance is only 1.14 × 10(-5), as shown by Monte Carlo simulation. Thus, in contrast to our previous conclusions, these novel data indicate that common molecular causes of NS-ARMR do exist, and in the Iranian population, the most frequent ones may well account for several percent of the patients. These findings will be instrumental in the identification of the underlying genes.     

Advances in quantifying apolipoproteins using LC-MS/MS technology: implications for the clinic

Introduction: Apolipoproteins play a key role in pre-, pro-, and anti-atherosclerotic processes and have become important circulating biomarkers for the prediction of cardiovascular disease (CVD) risk. Whereas currently clinical immunoassays are not available for most apolipoproteins and lack the capacity for multiplexing, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) allows simultaneous, highly-specific, and precise quantification of multiple apolipoproteins.

Areas covered: We discuss LC-MS/MS methods for quantification of apolipoproteins reported in the literature and highlight key requirements for clinical use. Besides the advances in sample preparation and LC-MS/MS technologies, this overview also discusses advances in proteoform analysis and applications of dried blood/plasma collection.

Expert commentary: Standardized quantification using LC-MS/MS technology has been demonstrated for apolipoprotein A-I and B. However, for implementation in clinical CVD risk assessment, LC-MS/MS must bring significant added clinical value in comparison to fast, standardized, and straightforward clinical (immuno)assays. Ongoing advances in accuracy and multiplexing capacity of LC-MS/MS, nonetheless, bear potential to enable standardized and interpretable personalized profiling of a patient’s CVD risk by simultaneous quantification of multiple apolipoproteins and -variants. We, moreover, anticipate further personalization of CVD risk assessment by the potential of LC-MS/MS to enable simultaneous genotyping and remote monitoring using dried blood/plasma collection devices.     

Complement induction and complement evasion in patients with cerebral aspergillosis

Cerebral aspergillosis is a mostly lethal infection of the central nervous system. Former results identified low cerebral complement levels as one cause for insufficient immune reaction. Therefore we studied cerebral complement expression after fungal invasion and investigated putative mechanisms of Aspergillus spp to cope with the complement-induced selection pressure. Brain tissue derived from patients with cerebral aspergillosis or non-infected individuals was analyzed immunohistochemically for complement synthesis. Correlations between expression levels were determined statistically. Increased complement synthesis, a prerequisite for strengthened antifungal potency, was visible in resident astrocytes, neurons, oligodendrocytes as well as in infiltrating macrophages after fungal infection. Surprisingly, microglia, although regarded as major immune cells, only marginally participated in synthesis of most complement proteins. Several evasion mechanisms were found that help the fungus to establish a cerebral infection even in the presence of complement: Fungal hyphae limit the surface deposition of C3 and thus interfere with complement-dependent phagocytosis. Furthermore, the "sealing off" in brain abscesses not only inhibits fungal spreading but also forms protection shields against complement attack. Complement indeed seems to represent an important selection pressure and evokes the development of fungal evasion mechanisms. Counteractions for these evasion processes might represent interesting therapeutic approaches.     

The H3 receptor is involved in cholecystokinin inhibition of food intake in rats.

We investigated the peripheral effects of an H3-receptor agonist and an H3-receptor antagonist (R)alpha-methylhistamine (Ralpha-MeHA) and thioperamide, respectively, on basal feeding and the CCK8-induced inhibition of food intake in rat. Intraperitoneal injection of thioperamide reduced food intake in a dose-dependent manner with maximal inhibition (35%, P<0.01 vs saline) at 3 mg/kg. (R)alpha-MeHA (0.3-3 mg/kg i.p.), an H3-receptor agonist alone had no effect on feeding but reversed the thioperamide-induced inhibition of food intake in a dose-dependent manner. The maximal feeding inhibitory dose of thioperamide (3 mg.kg i.p) increased by 40% and 22 % (P<0.01 vs saline) brain and stomach histamine contents, respectively. Histamine (0.3 - 6 mg/kg i.p.) and CCK-8 (3 - 30 microg/kg i.p) also inhibited food intake in a dose-dependent manner. Inhibition was 20% to 40% for histamine and 40% to 80% (P<0.01 vs saline) for CCK8. CCK-8 inhibition of feeding was increased by thioperamide and prevented by (R)alpha-MeHA in a dose-dependent way. In addition, CCK-8 did not reduce food intake if rats were pretreated with pyrilamine or ranitidine postsynaptic H1- and H2-receptor antagonists respectively. Our data suggest that the H3-receptor is involved in basal feeding. They also suggest that CCK satiety depends upon the release of histamine which acts on the H2- and H1-receptors, the final mediators of this effect.     

Molecular characterization of WFS1 in an Iranian family with Wolfram syndrome reveals a novel frameshift mutation associated with early symptoms

Wolfram syndrome (WS) is a rare autosomal recessive neurodegenerative disorder that represents a likely source of childhood diabetes especially among countries in the consanguinity belt. The main responsible gene is WFS1 for which over one hundred mutations have been reported from different ethnic groups. The aim of this study was to identify the molecular etiology of WS and to perform a possible genotype–phenotype correlation in Iranian kindred.