The abundance of an invasive freshwater snail Tarebia granifera (Lamarck, 1822) in the Nseleni River,South Africa

The invasive freshwater snail Tarebia granifera (Lamarck, 1822) was first reported in South Africa in 1999 and it has become widespread across the country, with some evidence to suggest that it reduces benthic macroinvertebrate biodiversity. The current study aimed to identify the primary abiotic drivers behind abundance patterns of T. granifera, by comparing the current abundance of the snail in three different regions, and at three depths, of the highly modified Nseleni River in KwaZulu-Natal, South Africa. Tarebia granifera was well established throughout the Nseleni River system, with an overall preference for shallow waters and seasonal temporal patterns of abundance. Although it is uncertain what the ecological impacts of the snail in this system are, its high abundances suggest that it should be controlled where possible and prevented from invading other systems in the region.     

Tauroursodeoxycholic acid increases neural stem cell pool and neuronal conversion by regulating mitochondria-cell cycle retrograde signaling

The low survival and differentiation rates of stem cells after either transplantation or neural injury have been a major concern of stem cell-based therapy. Thus, further understanding long-term survival and differentiation of stem cells may uncover new targets for discovery and development of novel therapeutic approaches. We have previously described the impact of mitochondrial apoptosis-related events in modulating neural stem cell (NSC) fate. In addition, the endogenous bile acid, tauroursodeoxycholic acid (TUDCA) was shown to be neuroprotective in several animal models of neurodegenerative disorders by acting as an anti-apoptotic and anti-oxidant molecule at the mitochondrial level. Here, we hypothesize that TUDCA might also play a role on NSC fate decision. We found that TUDCA prevents mitochondrial apoptotic events typical of early-stage mouse NSC differentiation, preserves mitochondrial integrity and function, while enhancing self-renewal potential and accelerating cell cycle exit of NSCs. Interestingly, TUDCA prevention of mitochondrial alterations interfered with NSC differentiation potential by favoring neuronal rather than astroglial conversion. Finally, inhibition of mitochondrial reactive oxygen species (mtROS) scavenger and adenosine triphosphate (ATP) synthase revealed that the effect of TUDCA is dependent on mtROS and ATP regulation levels. Collectively, these data underline the importance of mitochondrial stress control of NSC fate decision and support a new role for TUDCA in this process.     

A novel activity of microsomal epoxide hydrolase: metabolism of the endocannabinoid 2-arachidonoylglycerol

Microsomal epoxide hydrolase (EPHX1, EC 3.3.2.9) is a highly abundant α/β-hydrolase enzyme that is known for its catalytical epoxide hydrolase activity. A wide range of EPHX1 functions have been demonstrated including xenobiotic metabolism; however, characterization of its endogenous substrates is limited. In this study, we present evidence that EPHX1 metabolizes the abundant endocannabinoid 2-arachidonoylglycerol (2-AG) to free arachidonic acid (AA) and glycerol. The EPHX1 metabolism of 2-AG was demonstrated using commercially available EPHX1 microsomes as well as PC-3 cells overexpressing EPHX1. Conversely, EPHX1 siRNA markedly reduced the EPHX1 expression and 2-AG metabolism in HepG2 cells and LNCaP cells. A selective EPHX1 inhibitor, 10-hydroxystearamide, inhibited 2-AG metabolism and hydrolysis of a well-known EPHX1 substrate, cis-stilbene oxide. Among the inhibitors studied, a serine hydrolase inhibitor, methoxy-arachidonyl fluorophosphate, was the most potent inhibitor of 2-AG metabolism by EPHX1 microsomes. These results demonstrate that 2-AG is an endogenous substrate for EPHX1, a potential role of EPHX1 in the endocannabinoid signaling and a new AA biosynthetic pathway.     

Differential responsiveness to immunoablative therapy in refractory rheumatoid arthritis is associated with level and avidity of anti-cyclic citrullinated protein autoantibodies: a case study

In order to identify pathogenic correlates of refractory rheumatoid arthritis (RA), antibodies against anti-cyclic citrullinated protein (ACPAs) were investigated in RA patients in whom the dysregulated immune system had been ablated by high-dose chemotherapy (HDC) and autologous haematopoietic stem cell transplantation (HSCT). Six patients with refractory RA were extensively characterized in terms of levels of total immunoglobulins, RA-specific autoantibodies (ACPAs and rheumatoid factor) and antibodies against rubella, tetanus toxoid (TT) and phosphorylcholine before and after HDC plus HSCT. Additionally, the avidity of ACPAs was measured before and after treatment and compared with the avidity of TT antibodies following repeated immunizations. Synovial biopsies were obtained by arthroscopy before HDC plus HSCT, and analyzed by immunohistochemistry. In the three patients with clinically long-lasting responses to HDC plus HSCT (median 423 days), significant reductions in ACPA-IgG levels after therapy were observed (median level dropped from 215 to 34 arbitrary units/ml; P = 0.05). In contrast, stable ACPA-IgG levels were observed in three patients who relapsed shortly after HDC plus HSCT (median of 67 days). Clinical responders had ACPA-IgG of lower avidity (r = 0.75; P = 0.08) and higher degree of inflammation histologically (r = 0.73; P = 0.09). Relapse (after 38 to 530 days) in all patients was preceded by rising levels of low avidity ACPA-IgG (after 30 to 388 days), in contrast to the stable titres of high avidity TT antibodies. In conclusion, humoral autoimmune responses were differentially modulated by immunoablative therapy in patients with synovial inflammation and low avidity ACPA-IgG autoantibodies as compared with patients with high levels of high avidity ACPA-IgG. The distinct clinical disease course after immunoablative therapy based on levels and avidity of ACPA-IgG indicates that refractory RA is not a single disease entity.     

Adrenomedullin 2/intermedin regulates HLA-G in human trophoblasts

Adrenomedullin 2 (ADM2), also referred to as intermedin (IMD), is expressed in trophoblast cells in human placenta and enhances the invasion and migration of first-trimester HTR-8SV/neo cells. Further infusion of ADM2 antagonist in pregnant rat causes fetoplacental growth restriction, suggesting a role for ADM2 in maintaining a successful pregnancy. This study was undertaken to assess whether ADM2 protein is present in decidual tissue and colocalized with HLA-G-positive cytotrophoblast cells and natural killer cells; to assess whether ADM2 regulates expression of HLA-G in trophoblast cells; and to identify whether mitogen-activated protein kinase (MAPK) signaling pathway is involved in ADM2-induced trophoblast cell invasion and migration. Using immunohistochemical methods and RT-PCR, this study shows that ADM2 protein is colocalized with HLA-G-expressing cytotrophoblast cells as well as with NCAM1 (CD56) immunoreactivity in human first-trimester decidual tissue, and that ADM2 mRNA is expressed in peripheral blood natural killer cells. Further, ADM2 dose dependently increases the expression of HLA-G antigen in HTR-8SV/neo cells as well as in term placental villi explants, suggesting involvement of ADM2 in the regulation of HLA-G in trophoblast cells. In addition, interference with the activity of RAF and MAPK3/1 by their inhibitors, manumycin and U0126, respectively, reduces ADM2-induced HTR-8SV/neo cell invasion and migration. In summary, this study suggests a potential involvement for ADM2 in regulating HLA-G antigen at the maternal-fetal interface in human pregnancy and facilitating trophoblast invasion and migration via MAPK3/1 phosphorylation.     

Polarized light based scheme to monitor column performance in a continuous foam fractionation column

Background  

A polarized light scattering technique was used to monitor the performance of a continuously operated foam fractionation process. The S ₁₁ and S ₁₂ parameters, elements of the light scattering matrix, combined together (S ₁₁ +S ₁₂) have been correlated with the bubble size and liquid content for the case of a freely draining foam. The performance of a foam fractionation column is known to have a strong dependence on the bubble size distribution and liquid hold up in foam. In this study the enrichment is used as a metric, representative of foam properties and column performance, and correlated to the S ₁₁ +S ₁₂ parameter.     

Microsatellite diversities and gene flow in the tsetse fly,Glossina morsitans s.l

Tsetse flies occupy discontinuous habitats and gene flow among them needs to be investigated in anticipation of area-wide control programs. Genetic diversities were estimated at six microsatellite loci in seven Glossina morsitans submorsitans Newstead (Diptera: Glossinidae) populations and five microsatellite loci in six G. m. morsitans Westwood populations. Nei's unbiased diversities were 0.808 and 76 alleles in G. m. submorsitans and 0.727 and 55 alleles in G. m. morsitans. Diversities were less in three laboratory cultures. Matings were random within populations. Populations were highly differentiated genetically. Populations were strongly subdivided, as indicated by fixation indices (F(ST)) of 0.18 in G. m. morsitans and 0.17 in G. m. submorsitans. 35% of the genetic variance in G. m. submorsitans was attributed to differences between populations from The Gambia and Ethiopia. All available genetic evidence suggests that genetic drift is much greater than gene flow among G. morsitans s.l. populations.     

Assessment of post extraction complications in Indians

Extraction is one of the commonest procedures in dentistry. Therefore, it is of interest to evaluate the post extraction complications in patients undergoing extractions of permanent teeth. A total of 70 adult patients who had undergone dental extractions and presented with post -operative complications were included in the study and evaluated. Data collected was statistically analyzed using SPSS software and results obtained. Most of the patients with post extraction complications were in the age group of 31-40 years (21.6%), followed by 21-30 (20.2%) and 61-70 years (20.2%). Dry socket (39.19%) was the common post extraction complication in our study especially in the age group of 31-40 years. There was a statistically significant association between age of the patients and the post extraction complications (p<0.001). In our study, post extraction complications were commonly observed in age group of 31-40 years with a predilection for males. Dry socket was the most common post extraction complication. Age of the patient has a significant effect on post extraction complications. However, gender, smoking habits and systemic diseases have no influence on post extraction complications.