Long-term cultured human skin mast cells are suitable for pharmacological studies of anti-allergic drugs due to high responsiveness to FcεRI cross-linking

Human skin mast cells proliferated in the presence of interleukin (IL)-4+SCF (expanding 18-fold in 8 weeks) and acquired profound responsiveness towards high affinity IgE receptor (FcεRI) cross-linking, liberating about 75% of their histamine. In a proof-of-concept, we found that these cells are useful for pharmacological testing. Even a subtle inhibition of degranulation can be visualized. This model might prove valuable in tests of novel anti-allergic drugs.     

Increased p wave dispersion in elite athletes

Background

Few studies have been performed on P wave indices in athletes. The aim of this study was to determine the behaviour of maximum P wave duration (Pmax), minimum P wave duration (Pmin) and P wave dispersion (PWD) in young high performance athletes, as well as the relationship of PWD with training history, heart rate (HR) and echocardiographic parameters.

Methods

We performed a cross-sectional observational study in 38 athletes of high performance in sports: water polo, distance running and weight lifting compared with 34 sedentary controls.

Results

The average age in both groups was 20.6 years. Note that PWD was increased in athletes (57 ± 14 ms vs. 40 ± 12 ms, p <0.001) while Pmin was significantly lower (57 ± 13 ms vs. 72 ± 13 ms, p <0.001), and there was no difference when comparing Pmax (114 ± 9 ms vs. 117 ± 14 ms, p> 0.05). The correlation between the duration of training (r = 0.511) and resting HR (r = 0.461) with PWD was significant (p <0.01).

Conclusions

PWD is increased in young athletes of high performance and was positively correlated with duration of training and baseline HR. The increase in PWD was secondary to a significant decrease in Pmin.     

Extraction of the climatic signal for moisture from tree-ring chronologies of Altai-Sayan mountain forest-steppes

Studies in Central Asia (Altai-Sayan region, northwest and central Mongolia) have shown that trees growing in arid conditions of mountain forest-steppes have a mixed and unstable climatic response. It is obvious that this nature of the climatic response of trees prevents the use of tree-ring chronologies for climate reconstruction. In this connection, it is necessary to separate the climatic signal of tree-ring chronologies, i.e., extract the signal for moisture. This paper proposes a method for separating the climatic signal of tree-ring chronologies of mountain forest-steppes, and reports estimates of its reliability by two independent methods. Analysis of the chronologies obtained after separation of the signal, based on meteorological and hydrological data, has shown that these chronologies can be used for climate reconstructions.     

Correlation of clinical trachoma and infection in Aboriginal communities

Background

Trachoma is the leading infectious cause of blindness due to conjunctival infection with Chlamydia trachomatis. The presence of active trachoma and evidence of infection are poorly correlated and a strong immunologically-mediated inflammatory response means that clinical signs last much longer than infection. This population-based study in five Aboriginal communities endemic for trachoma in northern Australia compared a fine grading of clinical trachoma with diagnostic positivity and organism load.

Methods

A consensus fine grading of trachoma, based on clinical assessment and photograding, was compared to PCR, a lipopolysacharide (LPS)-based point-of-care (POC) and a 16S RNA-based nucleic acid amplification test (NAAT). Organism load was measured in PCR positive samples.

Results

A total of 1282 residents, or 85.2% of the study population, was examined. Taking the findings of both eyes, the prevalence of trachomatous inflammation-follicular (TF) in children aged 1–9 years was 25.1% (96/383) of whom 13 (13.7%) were PCR positive on the left eye. When clinical data were limited to the left eye as this was tested for PCR, the prevalence of TF decreased to 21.4% (82/383). The 301 TF negative children, 13 (4.3%) were PCR positive. The fine grading of active trachoma strongly correlated with organism load and disease severity (rs = 0.498, P = 0.0004). Overall, 53% of clinical activity (TF₁ or TF₂) and 59% of PCR positivity was found in those with disease scores less than the WHO simplified grade of TF.

Conclusion

Detailed studies of the pathogenesis, distribution and natural history of trachoma should use finer grading schemes for the more precise identification of clinical status. In low prevalence areas, the LPS-based POC test lacks the sensitivity to detect active ocular infection and nucleic acid amplification tests such as PCR or the 16S-RNA based NAAT performed better. Trachoma in the Aboriginal communities requires specific control measures.     

Host response to the presence of Helicobacter spp. DNA in the liver of patients with chronic liver diseases

Literature data indicate an association between the presence of Helicobacter spp. in the liver and the development of hepatocellular carcinoma (HCC). However, the role of H. pylori infections in chronic liver diseases (CLD) remains controversial. The aim of this study was to detect Helicobacter spp. DNA in patients with CLD, and to investigate the host response to the presence of the bacterium in the liver. Helicobacter spp. DNA was detected in 59% samples. H.pylori was the most prevalent species (94%). We estimated the expression level of IL-1 and IL-8 genes. The presence of Helicobacter spp. did not have a significant effect on the gene expression of IL-8 and IL-1.     

Plasma biomarkers of brain atrophy in Alzheimer's disease

Peripheral biomarkers of Alzheimer''s disease (AD) reflecting early neuropathological change are critical to the development of treatments for this condition. The most widely used indicator of AD pathology in life at present is neuroimaging evidence of brain atrophy. We therefore performed a proteomic analysis of plasma to derive biomarkers associated with brain atrophy in AD. Using gel based proteomics we previously identified seven plasma proteins that were significantly associated with hippocampal volume in a combined cohort of subjects with AD (N = 27) and MCI (N = 17). In the current report, we validated this finding in a large independent cohort of AD (N = 79), MCI (N = 88) and control (N = 95) subjects using alternative complementary methods—quantitative immunoassays for protein concentrations and estimation of pathology by whole brain volume. We confirmed that plasma concentrations of five proteins, together with age and sex, explained more than 35% of variance in whole brain volume in AD patients. These proteins are complement components C3 and C3a, complement factor-I, γ-fibrinogen and alpha-1-microglobulin. Our findings suggest that these plasma proteins are strong predictors of in vivo AD pathology. Moreover, these proteins are involved in complement activation and coagulation, providing further evidence for an intrinsic role of these pathways in AD pathogenesis.     

Cellular renewal and improvement of local cell effector activity in peritoneal cavity in response to infectious stimuli

The peritoneal cavity (PerC) is a singular compartment where many cell populations reside and interact. Despite the widely adopted experimental approach of intraperitoneal (i.p.) inoculation, little is known about the behavior of the different cell populations within the PerC. To evaluate the dynamics of peritoneal macrophage (MØ) subsets, namely small peritoneal MØ (SPM) and large peritoneal MØ (LPM), in response to infectious stimuli, C57BL/6 mice were injected i.p. with zymosan or Trypanosoma cruzi. These conditions resulted in the marked modification of the PerC myelo-monocytic compartment characterized by the disappearance of LPM and the accumulation of SPM and monocytes. In parallel, adherent cells isolated from stimulated PerC displayed reduced staining for β-galactosidase, a biomarker for senescence. Further, the adherent cells showed increased nitric oxide (NO) and higher frequency of IL-12-producing cells in response to subsequent LPS and IFN-γ stimulation. Among myelo-monocytic cells, SPM rather than LPM or monocytes, appear to be the central effectors of the activated PerC; they display higher phagocytic activity and are the main source of IL-12. Thus, our data provide a first demonstration of the consequences of the dynamics between peritoneal MØ subpopulations by showing that substitution of LPM by a robust SPM and monocytes in response to infectious stimuli greatly improves PerC effector activity.     

New insights into how adipocytes sense their triglyceride stores. Is cholesterol a signal?

In recent years, our view of adipose tissue has evolved from a passive sink for energy storage to an active tissue producing multiple molecules acting on various tissues in different aspects of energy homeostasis. The production of adipose-derived secretory products is tightly regulated as a function of adipocyte lipid accumulation, but the mechanisms by which fat cells are able to sense the levels of their triglyceride stores still remains largely unknown. This paper reviews new insights into this question taking cholesterol as a potential intracellular signaling molecule.     

High-level expression and immunogenic properties of the recombinant rabbit hemorrhagic disease virus VP60 capsid protein obtained in Pichia pastoris

The VP60 capsid protein from rabbit hemorrhagic disease virus (RHDV) (Spanish isolate AST/89) was cloned and expressed in Pichia pastoris. The transformed yeast was grown at high cell density and an expression level of about 1.5 g VP60L(-1) culture was obtained. The protein was detected associated with the cell debris fraction of the recombinant yeast after mechanical disruption. It was purified by a simple method and was obtained N-glycosylated with purity of approximately 70% as deduced from densitometry scan analysis. The recombinant product was antigenically similar to the native capsid protein as determined with polyclonal antibodies obtained from rabbits vaccinated with VP60 protein purified from native virus. The immunogenicity of VP60 protein purified from P. pastoris was demonstrated by ELISA in a vaccination experiment conducted with two groups of rabbits subcutaneously immunized. Animals vaccinated with VP60 in Freund's incomplete adjuvant developed a significant (p<0.01) virus-specific antibody response while the group injected with placebo remained seronegative. Preliminary results showed that the antigen administered within the cell debris fraction of the transformed yeast protected rabbits immunized by the oral route against an intramuscular challenge with 100 LD50 (16,000 hemagglutination units) of homologous virus.