Proteoglycan Synthesis and Golgi Organization in Polarized Epithelial Cells

A large number of complex glycosylation mechanisms take place in the Golgi apparatus. In epithelial cells, glycosylated protein molecules are transported to both the apical and the basolateral surface domains. Although the prevailing view is that the Golgi apparatus provides the same lumenal environment for glycosylation of apical and basolateral cargo proteins, there are indications that proteoglycans destined for the two opposite epithelial surfaces are exposed to different conditions in transit through the Golgi apparatus. We will here review data relating proteoglycan and glycoprotein synthesis to characteristics of the apical and basolateral secretory pathways in epithelial cells.     

Congenital deformity of the paw in a captive tiger: case report

Background

Although Morbillivirus and Toxoplasma gondii have emerged as important pathogens for several cetaceans populations over the last 20 years, they have never been identified together in a Mysticete. In particular, morbilliviral infection has been never described in the Mediterranean fin whale population.

Case presentation

On January 2011 an adult male of fin whale (Balaenoptera physalus) stranded along the Tyrrhenian coastline of Italy. During necropsy, tissue samples from heart, skeletal muscle, mesenteric lymph nodes, liver, spleen, lung, and kidney were collected and subsequently analyzed for Morbillivirus and Toxoplasma gondii by microscopic and molecular methods. Following the detailed necropsy carried out on this whale, molecular analysis revealed, for the first time, the simultaneous presence of a Dolphin Morbillivirus (DMV) and T. gondii infection coexisting with each other, along with high organochlorine pollutant concentrations, with special reference to DDT.

Conclusion

This report, besides confirming the possibility for Mysticetes to be infected with DMV, highlights the risk of toxoplasmosis in sea water for mammals, already immunodepressed by concurrent factors as infections and environmental contaminants.     

Convergent evolution of gigantism in damselflies of Africa and South America? Evidence from nuclear and mitochondrial sequence data

Extreme large body size is rare in modern Zygoptera (damselflies). Only the South and Central American damselfly family Pseudostigmatidae and one African species, Coryphagrion grandis, share the morphological trait of gigantism. By means of phylogenetic analyses using two mitochondrial markers (16S rDNA and ND1) and one nuclear marker (EF1) in combination with an existing morphological data set, we trace the evolution of gigantism in damselflies. Individual and combined data sets were analyzed using the maximum parsimony, minimum evolution and maximum likelihood algorithms. Regardless of the algorithm used and the data set analyzed all principal tree topologies support a monophyly of the damselfly taxa displaying giant body size. This supports the view that the evolution of gigantism in damselflies from Africa and South America is not the result of convergent evolution due to strikingly similar habitat preferences, but rather the result of close genealogical relationship. Because modern odonates evolved before the split of Africa from Gondwanaland, the proposed phylogeny suggests that C. grandis represents a Gondwana relict.     

The acute effects of mechanical vibration on power output in the bench press

This study was designed to investigate the effect of mechanical vibration on acute power output in the bench press exercise. Ten male subjects who were experienced in resistance training participated in this study. Each subject performed 3 sets of 3 repetitions in the bench press exercise using a load equal to 70% of 1 repetition maximum in each of 2 sessions separated by 3 days. One session served as the experimental (vibration) condition, whereas the other session served as the control (no vibration) condition. The intervention (vibration or control) was applied between sets 2 and 3. The vibration was applied by a vibrating barbell apparatus held by the subjects while lying supine on a bench. The only difference between the 2 conditions was the vibration of the barbell apparatus during the vibration condition. Peak and average power were calculated during each bench press set to determine whether power output differed following vibration compared to control. Average power was significantly higher for the vibration condition compared to the control (525 +/- 74 vs. 499 +/- 71 W; p = 0.01). There was also a trend toward an increase in peak power in the vibration condition (846 +/- 168 by vs. 799 +/- 149 W; p = 0.06). In general, peak and average power output were higher following the vibration intervention compared to control. However, the sets prior to vibration application during the vibration condition also demonstrated higher power outputs compared with the control condition, which contributed to the main effect for the vibration condition. These results suggest that factors other than the vibration intervention influenced task performance during the vibration condition. We suggest that psychological factors related to the novelty of the vibration intervention were involved. These factors may partially explain the conflicting results of previous investigations that examined vibration as an exercise intervention.     

Climatically driven synchrony of gerbil populations allows large-scale plague outbreaks

In central Asia, the great gerbil (Rhombomys opimus) is the main host for the bacterium Yersinia pestis, the cause of bubonic plague. In order to prevent plague outbreaks, monitoring of the great gerbil has been carried out in Kazakhstan since the late 1940s. We use the resulting data to demonstrate that climate forcing synchronizes the dynamics of gerbils over large geographical areas. As it is known that gerbil densities need to exceed a threshold level for plague to persist, synchrony in gerbil abundance across large geographical areas is likely to be a condition for plague outbreaks at similar large scales. Here, we substantiate this proposition through autoregressive modelling involving the normalized differentiated vegetation index as a forcing covariate. Based upon predicted climate changes, our study suggests that during the next century, plague epizootics may become more frequent in central Asia.     

Interferon alpha induces cell death through interference with interleukin 6 signaling and inhibition of STAT3 activity

In multiple myeloma, which commonly depends on interleukin 6, IL-6, survival signaling induced by this cytokine is largely mediated by activation of STAT3. Interferon alpha (IFNalpha) treatment of cell lines derived from multiple myeloma or of myeloma tumor cells ex vivo leads to apoptosis. In this study we demonstrate that IFNalpha treatment of the two myeloma cell lines, U266-1984 and U-1958, results in the decrease of STAT3 activity as demonstrated by a diminished STAT3/3 DNA-binding activity and the shift from STAT3/3 towards STAT1/1 and STAT3/1 complexes in EMSA, leading to the down-regulation of known STAT3 target genes such as Bcl-X(L), Mcl-1 and survivin. Ectopic expression of a form of STAT3, STAT3C, rescued U266-1984 cells from IFNalpha-induced apoptosis. IFNalpha promoted sustained accumulation of tyrosine phosphorylated STAT3C in the nucleus and a prolonged DNA binding of the STAT3/3 homodimers in EMSA. The shift towards a sustained STAT3 response in IFNalpha-treated STAT3C-transfected cells led to a hyper-induction of Bcl-2 and Mcl-1 proteins. Thus our data demonstrated that IFNalpha is able to interfere with IL-6 signaling by inhibiting STAT3 activity and that the abrogation of STAT3 activity accounts for the ability of IFNalpha to induce apoptosis in myeloma cells.     

To strike or not to strike? House-staff attitudes and behaviors during a hospital work action.

Work actions by house staff are an infrequent response to sometimes difficult working conditions, but they can have a notable effect on institutional cohesiveness and represent a challenge to traditional notions of medical ethics. To determine the extent of participation in a hospital-wide doctors'' strike and factors associated with participation, we surveyed 432 house officers at a university-affiliated public hospital where a contract dispute had recently led to a 4-day work action. Of 257 respondents, 69% approved of the strike and 50% participated in it. Both strikers and nonstrikers agreed that quality of care and specific contract issues were important precipitants of the event. By logistic regression, factors independently associated with strike participation (P less than .05) included being unmarried, training in internal medicine or psychiatry, being in earlier stages of training, being assigned to an outpatient service at the time of the strike, holding a favorable view of physician activism, and perceiving nurses, faculty, peers, and the public to have favored the strike. These associations may provide a basis for understanding the individual and social determinants of house-staff strike activity.     

Consistent differences in protein distribution along the longitudinal axis in symptomatic carotid atherosclerotic plaques

Identifying proteins associated with a complicated atherosclerotic plaque phenotype would provide potential biomarkers for detection of patients at elevated risk for clinically overt disease. We hypothesized that the protein content of carotid atherosclerotic tissue differs between complicated segments located in the internal carotid artery (ICA) and more stable segments in the common carotid artery (CCA). Using differential proteomics, we aimed to identify proteins differentially expressed between these segments of symptomatic carotid plaques. Ten snap-frozen human endarterectomies were divided into ICA and CCA segments and compared using two-dimensional differential gel electrophoresis and liquid chromatography-mass spectrometry. This study setup allowed pair-wise comparison of complicated and more stable atherosclerotic tissue from the same individual. We identified 19 proteins with differential distribution between ICA and CCA segments. Among the proteins more abundant in ICA were S100A10, ferritin light chain and fibrinogen. Among the proteins more abundant in CCA were ApoE, actin and l-lactate dehydrogenase B. Immunohistochemical staining revealed that S100A10 was expressed in endothelial cells, in clusters of macrophages and foam cells, and co-localized with the urokinase-type plasminogen activator receptor, uPAR. In conclusion, the results support the concept of comparing segments within plaques. The identified proteins constitute potential markers of complicated atherosclerotic lesions. The previously reported function of S100A10 to regulate plasmin activity affecting both angiogenesis and macrophage invasion, together with our observation of its accumulation in complicated plaque segments, warrants further studies of its potential role as a drug target for treatment of advanced atherosclerosis.