Pericardial adipose tissue and the metabolic syndrome is increased in patients with chronic major depressive disorder compared to acute depression and controls

OBJECTIVE

Major depressive disorder (MDD) is associated with an estimated fourfold risk for premature death, largely attributed to cardiovascular disorders. Pericardial adipose tissue (PAT), a fat compartment surrounding the heart, has been implicated in the development of coronary artery disease. An unanswered question is whether people with chronic MDD are more likely to have elevated PAT volumes versus acute MDD and controls (CTRL).

METHODS

The study group consists of sixteen patients with chronic MDD, thirty-four patients with acute MDD, and twenty-five CTRL. PAT and adrenal gland volume were measured by magnetic resonance tomography. Additional measures comprised factors of the metabolic syndrome, cortisol, relative insulin resistance, and pro-inflammatory cytokines (interleukin-6; IL-6 and tumor necrosis factor-α, TNF-α).

RESULTS

PAT volumes were significantly increased in patients with chronic MDD>patients with acute MDD>CTRL. Adrenal gland volume was slightly enlarged in patients with chronic MDD>acute MDD>CTRL, although this difference failed to reach significance. The PAT volume was correlated with adrenal gland volume, and cortisol concentrations were correlated with depression severity, measured by BDI-2 and MADRS. Group differences were found concerning the rate of the metabolic syndrome, being most frequent in chronic MDD>acute MDD>CTRL. Further findings comprised increased fasting cortisol, increased TNF-α concentration, and decreased physical activity level in MDD compared to CTRL.

CONCLUSION

Our results extend the existing literature in demonstrating that patients with chronic MDD have the highest risk for developing cardiovascular disorders, indicated by the highest PAT volume and prevalence of metabolic syndrome. The correlation of PAT with adrenal gland volume underscores the role of the hypothalamus-pituitary-adrenal system as mediator for body-composition changes. Metabolic monitoring, health advices and motivation for the improvement of physical fitness may be recommended in depressed patients, in particular in chronic depression.

In vivo and in vitro characterization of a Plasmodium liver stage-specific promoter

Little is known about stage-specific gene regulation in Plasmodium parasites, in particular the liver stage of development. We have previously described in the Plasmodium berghei rodent model, a liver stage-specific (lisp2) gene promoter region, in vitro. Using a dual luminescence system, we now confirm the stage specificity of this promoter region also in vivo. Furthermore, by substitution and deletion analyses we have extended our in vitro characterization of important elements within the promoter region. Importantly, the dual luminescence system allows analyzing promoter constructs avoiding mouse-consuming cloning procedures of transgenic parasites. This makes extensive mutation and deletion studies a reasonable approach also in the malaria mouse model. Stage-specific expression constructs and parasite lines are extremely valuable tools for research on Plasmodium liver stage biology. Such reporter lines offer a promising opportunity for assessment of liver stage drugs, characterization of genetically attenuated parasites and liver stage-specific vaccines both in vivo and in vitro, and may be key for the generation of inducible systems.

Meteorological influences on swarm emergence in honey bees (Hymenoptera: Apidae) as detected by crowdsourcing

A crowdsourced dataset of 1,335 honey bee (Apis mellifera L.) swarm events in Germany in 2011 was created by beekeepers, public institutions, and members of the public and analyzed with respect to prevailing weather. The emergence of swarms appeared to be influenced by temperature and rainfall. On successive warm days in May the number of swarming events increased noticeably, but during a mid-month frost event the number of swarming events dropped markedly. Swarming events also occurred only rarely on rainy days. This study showed how crowdsourcing can be used to generate large, useful, phenological datasets.

Nematode-induced interference with the anti-Plasmodium CD8+ T-cell response can be overcome by optimizing antigen administration

Malaria is still responsible for up to 1 million deaths per year worldwide, highlighting the need for protective malaria vaccines. Helminth infections that are prevalent in malaria endemic areas can modulate immune responses of the host. Here we show that Strongy-Ioides ratti, a gut-dwelling nematode that causes transient infections, did not change the efficacy of vaccination against Plasmodium berghei. An ongoing infection with Litomosoides sigmodontis, a tissue-dwelling filaria that induces chronic infections in BALB/c mice, significantly interfered with vaccination efficacy. The induction of P. berghei circumspor-ozoite protein (CSP)-specific CD8(+) T cells, achieved by a single immunization with a CSP fusion protein, was diminished in L. sigmodontis-infected mice. This modulation was reflected by reduced frequencies of CSP-specific CD8(+) T cells, reduced CSP-specific IFN-y and TNF-a production, reduced CSP-specific cytotoxicity, and reduced protection against P. berghei challenge infection. Implementation of a more potent vaccine regime, by first priming with CSP-expressing recombinant live Salmonella prior to CSP fusion protein immunization, restored induction of CSP-specific CD8(+) T cells and conferred almost sterile immunity to P. berghei challenge infection also in L. sigmodontis-infected mice. In summary, we show that appropriate vaccination regimes can overcome helminth-induced interference with vaccination efficacy.

Autophagy gene variant IRGM -261T contributes to protection from tuberculosis caused by Mycobacterium tuberculosis but not by M. africanum strains

The human immunity-related GTPase M (IRGM) has been shown to be critically involved in regulating autophagy as a means of disposing cytosolic cellular structures and of reducing the growth of intracellular pathogens in vitro. This includes Mycobacterium tuberculosis, which is in agreement with findings indicating that M. tuberculosis translocates from the phagolysosome into the cytosol of infected cells, where it becomes exposed to autophagy. To test whether IRGM plays a role in human infection, we studied IRGM gene variants in 2010 patients with pulmonary tuberculosis (TB) and 2346 unaffected controls. Mycobacterial clades were classified by spoligotyping, IS6110 fingerprinting and genotyping of the pks1/15 deletion. The IRGM genotype −261TT was negatively associated with TB caused by M. tuberculosis (OR 0.66, CI 0.52–0.84, P_nominal 0.0009, P_corrected 0.0045) and not with TB caused by M. africanum or M. bovis (OR 0.95, CI 0.70–1.30. P 0.8). Further stratification for mycobacterial clades revealed that the protective effect applied only to M. tuberculosis strains with a damaged pks1/15 gene which is characteristic for the Euro-American (EUAM) subgroup of M. tuberculosis (OR 0.63, CI 0.49–0.81, P_nominal 0.0004, P_corrected 0.0019). Our results, including those of luciferase reporter gene assays with the IRGM variants −261C and −261T, suggest a role for IRGM and autophagy in protection of humans against natural infection with M. tuberculosis EUAM clades. Moreover, they support in vitro findings indicating that TB lineages capable of producing a distinct mycobacterial phenolic glycolipid that occurs exclusively in strains with an intact pks1/15 gene inhibit innate immune responses in which IRGM contributes to the control of autophagy. Finally, they raise the possibility that the increased frequency of the IRGM −261TT genotype may have contributed to the establishment of M. africanum as a pathogen in the West African population.

Autophagy is a process in which cell components are degraded by the lysosomal machinery. It has recently been described that activation of autophagy reduces the viability of M. tuberculosis in phagosomes due to an intimate autophagy-phagocytosis interaction. M. tuberculosis may also be directly accessible to autophagy, as M. tuberculosis was found to translocate into the cytoplasm. The immunity-related GTPase IRGM is a mediator of innate immune responses and induces autophagy. We have studied genetic variants of the human IRGM gene in a Ghanaian tuberculosis case-control group and found that the IRGM variant −261T provides relative protection against disease when the infection is caused by the Euro-American lineage of M. tuberculosis. This lineage is characterized by the pks1/15 seven base-pair (bp) deletion. The product of an intact pks1/15 gene, phenolic glycolipid-tb, might contribute to mycobacterial virulence by suppressing innate immune responses. It is, therefore, conceivable that only the Euro-American lineage is exposed to IRGM-triggered innate defence mechanisms. Our observations suggest that the increased frequency of the IRGM −261TT genotype may have allowed the establishment of M. africanum as a pathogen in West Africa.

Highly efficient subcloning of rodent malaria parasites by injection of single merosomes or detached cells

This protocol describes a method for obtaining rodent Plasmodium parasite clones with high efficiency, which takes advantage of the normal course of Plasmodium in vitro exoerythrocytic development. At the completion of development, detached cells/merosomes form, which contain hundreds to thousands of merozoites. As all parasites within a single detached cell/merosome derive from the same sporozoite, we predicted them to be genetically identical. To prove this, hepatoma cells were infected simultaneously with a mixture of Plasmodium berghei sporozoites expressing either GFP or mCherry. Subsequently, individual detached cells/merosomes from this mixed population were selected and injected into mice, resulting in clonal blood stage parasite infections. Importantly, as a large majority of mice become successfully infected using this protocol, significantly less mice are necessary than for the widely used technique of limiting dilution cloning. To produce a clonal P. berghei blood stage infection from a non-clonal infection using this procedure requires between 4 and 5 weeks.

Synthesis, photochemistry and application of (7-methoxycoumarin-4-yl)methyl-caged 8-bromoadenosine cyclic 3',5'-monophosphate and 8-bromoguanosine cyclic 3',5'-monophosphate photolyzed in the nanosecond time region

New caged derivatives of hydrolysis-resistant 8-bromoadenosine cyclic 3',5'-monophosphate (8-Br-cAMP) and 8-bromoguanosine cyclic 3',5'-monophosphate (8-Br-cGMP) are described. The compounds are the axial and equatorial isomers of the (7-methoxycoumarin-4-yl)methyl (MCM) esters of cyclic nucleotides. Synthesis is accomplished by treatment of 4-bromomethyl-7-methoxycoumarin with the tetra-n-butylammonium salts of the 8-bromo-substituted cyclic nucleotides or with the free acids of 8-Br-cAMP and 8-Br-cGMP in the presence of silver(I) oxide. MCM-caged 8-Br-cAMP and MCM-caged 8-Br-cGMP liberate 8-Br-cAMP and 8-Br-cGMP during irradiation with ultraviolet light within a few nanoseconds. They show favorable absorption properties and quantum yields and are resistant to hydrolysis in aqueous buffer solutions. The moderate fluorescence properties of the caged compounds in comparison with the strongly fluorescent 4-hydroxymethyl-7-methoxycoumarin (MCM-OH) photoproduct allow the indirect estimation of the amount of photolytically released cyclic nucleotides in aqueous buffer solutions using fluorescence measurements. Their usefulness for physiological studies has been examined in a mammalian cell line expressing the cyclic nucleotide-gated ion channel of bovine olfactory sensory neurons using the patch-clamp technique and confocal laser scanning microscopy. The caged compounds serve as efficient and rapid intracellular sources of 8-Br-cAMP and 8-Br-cGMP. However, at least in HEK 293 cells, fluorescence signals cannot be used to monitor the photolysis of MCM-caged 8-Br-cAMP and 8-Br-cGMP, due to quenching of the fluorescence of MCM-OH.

Follicular dendritic cells and presentation of antigen and costimulatory signals to B cells

This review focuses on how immunogens trapped by FDC in the form of Ag-Ab complexes productively signal B cells. In vitro. Ag-Ab complexes are poorly immunogenic but in vivo immune complexes elicit potent recall responses. FDC trap Ag-Ab complexes and make immune complex coated bodies or "iccosomes". B cells endocytose iccosomes, the Ag is processed, and T-cell help is elicited. In vitro, addition of FDC bearing appropriate Ag-Ab complex to memory T and B cells provoke potent recall responses (IgG and IgE). FDC also provide nonspecific costimulatory signals which augment B-cell proliferation and Ab production. B cell-FDC contact is important and interference with ICAM-1-LFA-1 interactions reduces FDC-mediated costimulation. Preliminary data suggest that a costimulatory signal may be delivered via CR2L on FDC binding CR2 on B cells. FDC can also stimulate B cells to become chemotactically active and can protect lymphocytes from apoptosis. FDC also appear to be rich in thiol groups and may replace reducing compounds such as 2 mercaptoethanol in cultures. In short, FDC-Ag specifically signals B cells through BCR, and FDC provide B cells with iccosomal-Ag necessary for processing to elicit T-cell help. In addition, FDC provide nonspecific signals that are important to promote B-cell proliferation, maintain viability, and induce chemotactic responsiveness.

24,25-(OH)2D3 regulates protein kinase C through two distinct phospholipid-dependent mechanisms

We have previously shown that 24,25-(OH)2D3 plays a major role in resting zone (RC) chondrocyte differentiation and that this vitamin D metabolite regulates protein kinase C (PKC). The aim of the present study was to identify the signal transduction pathway used by 24,25-(OH)2D3 to stimulate PKC activation. Confluent, fourth passage RC cells from rat costochondral cartilage were used to evaluate the mechanism of PKC activation. Treatment of RC cultures with 24,25-(OH)2D3 for 90 min produced a dose-dependent increase in diacylglycerol (DAG). Addition of R59022, a diacylglycerol kinase inhibitor, significantly increased PKC activity in cultures treated with 24,25-(OH)2D3. Addition of dioctanoylglycerol (DOG) to plasma membranes isolated from RC increased PKC activity 447-fold. Addition of pertussis toxin or cholera toxin to control cultures elevated basal PKC activity. When added together with 10(-9) M 24,25-(OH)2D3, there was an additive effect on PKC activity but in cultures treated with 10(-8) M 24,25-(OH)2D3, only the hormone-dependent stimulation of PKC was observed. The phospholipase C inhibitor, U73-122, had no effect on PKC activity, indicating that the DAG produced in response to 24,25-(OH)2D3 is not derived from phosphatidylinositol. Addition of the tyrosine kinase inhibitor, genistein, also had no effect on 24,25-(OH)2D3-stimulated PKC, further supporting the hypothesis that phospholipase C is not involved in the mechanism and that phospholipase D is responsible for the increase in DAG production. Phospholipase A2 inhibitors, quinacrine and AACOCF3, and the cyclooxygenase inhibitor indomethacin increased PKC activity in the RC cultures. Exogenous PGE2, one of the downstream products of phospholipase A2 action, inhibited PKC activity. These results suggest that 24,25-(OH)2D3 regulates PKC activity by two distinct phospholipid-dependent mechanisms: production of DAG via phospholipase D and inhibition of the production of PGE2 via inhibition of phospholipase A2 and cyclooxygenase.

Relationship between dental and skeletal maturation in Danish schoolchildren

Spearman correlation coefficients between the number of emerged permanent teeth and RUS (TW2 method) skeletal maturity scores were calculated among 1412 boys and 1332 girls, aged 7-14 yr, divided into 3-month age groups. "Moving averages" are presented of the correlation coefficients for every four 3-month age groups at a time. The pattern of the correlations differed between the sexes. However, in general, weak associations were found (mean r = 0.15-0.16), but correlations were significant at the 1% level in 8.5-9.5-yr-old girls and around 12 yr in both sexes. It is argued that skeletal, rather than dental, maturity should be assessed in adopted non-European children of unknown chronologic age.

Correlation between caries experience in primary and permanent dentition in birth-cohorts 1950-70

Caries experience in the primary molars and canines at 8 yr of age and in the permanent dentition at 16 was correlated in every fourth birth-cohort between 1950 and 1970 in a Danish community. Correlations between 0.44 and 0.55 were found. Cross-tabulation of the data also revealed close association, but prediction of individual high caries risk children based solely on screening for caries experience in the primary dentition is hardly cost-effective.