A comprehensive functional analysis of tissue specificity of human gene expression

Background

Periodic patterning of iterative structures is a fundamental process during embryonic organization and development. Studies have shown how gene networks are employed to pattern butterfly eyespots, fly bristles and vertebrate epithelial appendages such as teeth, feathers, hair and mammary glands. Despite knowledge of how these features are organized, little is known about how diversity in periodic patterning is generated in nature. We address this problem through the molecular analysis of oral jaw dental diversity in Lake Malawi cichlids, where closely related species exhibit from 1 to 20 rows of teeth, with total teeth counts ranging from around 10 to 700.

Results

We investigate the expression of conserved gene networks (involving bmp2, bmp4, eda, edar, fgf8, pax9, pitx2, runx2, shh and wnt7b) known to pattern iterative structures and teeth in other vertebrates. We show that spatiotemporal variation in expression pattern reflects adult morphological diversity among three closely related Malawi cichlid species. Combinatorial epithelial expression of pitx2 and shh appears to govern the competence both of initial tooth sites and future tooth rows. Epithelial wnt7b and mesenchymal eda are expressed in the inter-germ and inter-row regions, and likely regulate the spacing of these shh-positive units. Finally, we used chemical knockdown to demonstrate the fundamental role of hedgehog signalling and initial placode formation in the organization of the periodically patterned cichlid dental programme.

Conclusion

Coordinated patterns of gene expression differ among Malawi species and prefigure the future-ordered distribution of functional teeth of specific size and spacing. This variation in gene expression among species occurs early in the developmental programme for dental patterning. These data show how a complex multi-rowed vertebrate dentition is organized and how developmental tinkering of conserved gene networks during iterative pattern formation can impact upon the evolution of trophic novelty.     

Cytokinesis is blocked in mammalian cells transfected with Chlamydia trachomatis gene CT223

Background  

The chlamydiae alter many aspects of host cell biology, including the division process, but the molecular biology of these alterations remains poorly characterized. Chlamydial inclusion membrane proteins (Incs) are likely candidates for direct interactions with host cell cytosolic proteins, as they are secreted to the inclusion membrane and exposed to the cytosol. The inc gene CT223 is one of a sequential set of orfs that encode or are predicted to encode Inc proteins. CT223p is localized to the inclusion membrane in all tested C. trachomatis serovars.     

Short-term temperature effects on the anaerobic metabolism of glycogen accumulating organisms

Proliferation of glycogen accumulating organisms (GAO) has been identified as a potential cause of enhanced biological phosphorus removal (EBPR) failure in wastewater treatment plants (WWTP). GAO compete for substrate with polyphosphate accumulating organisms (PAO) that are the microorganisms responsible for the phosphorus removal process. In the present article, the effects of temperature on the anaerobic metabolism of GAO were studied in a broad temperature range (from 10 to 40 degrees C). Additionally, maximum acetate uptake rate of PAO, between 20 and 40 degrees C, was also evaluated. It was found that GAO had clear advantages over PAO for substrate uptake at temperatures higher than 20 degrees C. Below 20 degrees C, maximum acetate uptake rates of both microorganisms were similar. However, lower maintenance requirements at temperature lower than 30 degrees C give PAO metabolic advantages in the PAO-GAO competition. Consequently, PAO could be considered to be psychrophilic microorganisms while GAO appear to be mesophilic. These findings contribute to understand the observed stability of the EBPR process in WWTP operated under cold weather conditions. They may also explain the proliferation of GAO in WWTP and thus, EBPR instability, observed in hot climate regions or when treating warm industrial effluents. It is suggested to take into account the observed temperature dependencies of PAO and GAO in order to extend the applicability of current activated sludge models to a wider temperature range.     

Consequences of Repeated Blood-Brain Barrier Disruption in Football Players

The acknowledgement of risks for traumatic brain injury in American football players has prompted studies for sideline concussion diagnosis and testing for neurological deficits. While concussions are recognized etiological factors for a spectrum of neurological sequelae, the consequences of sub-concussive events are unclear. We tested the hypothesis that blood-brain barrier disruption (BBBD) and the accompanying surge of the astrocytic protein S100B in blood may cause an immune response associated with production of auto-antibodies. We also wished to determine whether these events result in disrupted white matter on diffusion tensor imaging (DT) scans. Players from three college football teams were enrolled (total of 67 volunteers). None of the players experienced a concussion. Blood samples were collected before and after games (n = 57); the number of head hits in all players was monitored by movie review and post-game interviews. S100B serum levels and auto-antibodies against S100B were measured and correlated by direct and reverse immunoassays (n = 15 players; 5 games). A subset of players underwent DTI scans pre- and post-season and after a 6-month interval (n = 10). Cognitive and functional assessments were also performed. After a game, transient BBB damage measured by serum S100B was detected only in players experiencing the greatest number of sub-concussive head hits. Elevated levels of auto-antibodies against S100B were elevated only after repeated sub-concussive events characterized by BBBD. Serum levels of S100B auto-antibodies also predicted persistence of MRI-DTI abnormalities which in turn correlated with cognitive changes. Even in the absence of concussion, football players may experience repeated BBBD and serum surges of the potential auto-antigen S100B. The correlation of serum S100B, auto-antibodies and DTI changes support a link between repeated BBBD and future risk for cognitive changes.     

Phytoplankton population density and volume as indicators of eutrophication in the eastern part of the Adriatic Sea

Population density and volume-biomass of microplankton, nanoplankton and total phytoplankton were analyzed at 14 stations along the eastern part of the Adriatic Sea. Based upon data frequency distribution, four categories of ecosystems were established in the investigated area. Criteria for ecosystem categorization and biological evaluation of eutrophication are proposed.     

Oxidized Low-Density Lipoprotein Contributes to Atherogenesis via Co-activation of Macrophages and Mast Cells

Oxidized low-density lipoprotein (OxLDL) is a risk factor for atherosclerosis, due to its role in endothelial dysfunction and foam cell formation. Tissue-resident cells such as macrophages and mast cells release inflammatory mediators upon activation that in turn cause endothelial activation and monocyte adhesion. Two of these mediators are tumor necrosis factor (TNF)-α, produced by macrophages, and histamine, produced by mast cells. Static and microfluidic flow experiments were conducted to determine the number of adherent monocytes on vascular endothelium activated by supernatants of oxLDL-treated macrophages and mast cells or directly by oxLDL. The expression of adhesion molecules on activated endothelial cells and the concentration of TNF-α and histamine in the supernatants were measured by flow cytometry and enzyme-linked immunosorbent assay, respectively. A low dose of oxLDL (8 μg/ml), below the threshold for the clinical presentation of coronary artery disease, was sufficient to activate both macrophages and mast cells and synergistically increase monocyte-endothelium adhesion via released TNF-α and histamine. The direct exposure of endothelial cells to a much higher dose of oxLDL (80 μg/ml) had less effect on monocyte adhesion than the indirect activation via oxLDL-treated macrophages and mast cells. The results of this work indicate that the co-activation of macrophages and mast cells by oxLDL is an important mechanism for the endothelial dysfunction and atherogenesis. The observed synergistic effect suggests that both macrophages and mast cells play a significant role in early stages of atherosclerosis. Allergic patients with a lipid-rich diet may be at high risk for cardiovascular events due to high concentration of low-density lipoprotein and histamine in arterial vessel walls.     

Polytrauma in elderly

The aim of this study is to present certain particularities in treating polytraumatized patients age of 65 and above. All of the patients were treated in our hospital. 413 patients were included in this 4 year study (2006-2010). Injury severity score was 17 and above (ISS > 17). Patients aged above 65 were sub grouped. In this 4-year period, we treated 52 or 13% elderly patients. In this subgroup there were 30 (58%) males and 22 (42%) females, with mean age of 74 (max age 95 years old). Demographic factors, injury mechanisms, patients resuscitation protocols, imaging used, etc. were also included as variables. Mortality rate in elderly patients was 31%, while in patients below 65 years of age as 12%. Taking relevant data into consideration, a special emphasis was given to certain circumstances of intensive and surgical treatment of elderly patients. A large portion of polytraumatized patients are consisted of elderly. Patients aged 65 and above have higher mortality rate with lower ISS in the mortal group and falls are the most frequent mechanism of trauma. In this study, we tried to emphasize some clinical implications when treating those patients, as well as importance in continuous medical staff education in trauma principles to minimize mortality rates.     

Differences in conative characteristics and perceived group cohesion of the basketball players playing in different positions in the team

Identification of differences in individual conative characteristics and in perceived group cohesion of the basketball players playing in different positions in the team could provide guidelines for a better selection of basketball players and better coaching work. The aim of our study was to determine the differences in relation to the positions of guards and forwards/centres, and the four major positions in the team. The final sample of subjects (74 basketball players) is selected from the initial sample of 107 subjects, selected from nine men's senior basketball teams that played in A-1 Croatian men's basketball league championship in 2006/2007. The results showed no statistically significant difference between basketball players who play in different positions in the team, neither in relation to two basic positions in the team (guards as opposed to forwards/centres), nor in relation to the four positions in the team (point guard, shooting guard, small forward, power forward/centre).     

Aggressive intestinal schwannoma malignum mimicking gynecological pathology - A case report

Primary malignant schwannoma of the small and large intestine is an extremely rare disease. Therefore, we are going to report an aggressive multifocal malignant intestinal schwannoma in a 66-year old female patient, that was primarily diagnosed as the gynecological tumor that, even after the surgical treatment, had a very quickly recurrence. Small intestine tumors may show images similar to an adnexal tumor, so it is difficult to differentiate one from another prior to the surgery. The patient did not suffer from neurofibromatosis type 1 (NF-1), disease that increases occurrence of malignant schwannoma in comparison with general population. These tumors are often diagnosed late, and radical surgical intervention does not guarantee longer survival. After surgical removal of macroscopically visible tumor masses from this patient, tumor formation within one month after the operation had reached the sizes of 83x66 mm and 85x75 mm respectively, with the occurrence of metastases in the liver, and thereafter the patient died. In differential diagnosis of adnexal tumor small intestine tumor has to be considered, especially if nonspecific symptoms are present.