Patterns and trends in cancer mortality in Colombia 1984–2008

BackgroundCancer has become increasingly acknowledged as a public health issue in Colombia. Rates of the most common malignancies have been generally increasing. We update an evaluation of mortality trends in the major cancers in Colombia one decade ago, discussing the trends in the context of cancer control.MethodsWe calculated the annual age-standardized mortality rates for the major cancer sites by sex between 1984 and 2008; we also present the estimated annual percentage change (EAPC) for the entire period and for the last decade.ResultsThere was an average of 32,000 cancer deaths annually in Colombia in the period studied. Overall cancer mortality rates decreased slightly in both men and women. The four most common sites of cancer death among men were stomach (17.6%), prostate (15.0%), lung (14.8%) and colorectum (6.5%). In women, the most common cancer sites were breast (12.3%), cervix (12.1%), stomach (11.5%) and lung (9.2%). Colorectal and CNS cancers exhibited the greatest increases (EAPC of 2.0% and 3.4% respectively) while the largest declines were seen for cancers of the larynx, stomach and oesophagus (EAPC between ?3% and ?4%). In the last decade, the greatest declines were seen in cervical cancer mortality rates (EAPC = ?3.2).ConclusionsThe slight decrease in mortality trends from all cancers combined is partially driven by the strong declines in mortality of stomach and cervical cancer. It may be still too early to properly evaluate trends in mortality due to other cancers and the relative impact of changing access to health care in Colombia.     

Rab11 Regulates Trafficking of Trans-sialidase to the Plasma Membrane through the Contractile Vacuole Complex of Trypanosoma cruzi

Trypanosoma cruzi is the etiologic agent of Chagas disease. Although this is not a free-living organism it has conserved a contractile vacuole complex (CVC) to regulate its osmolarity. This obligate intracellular pathogen is, in addition, dependent on surface proteins to invade its hosts. Here we used a combination of genetic and biochemical approaches to delineate the contribution of the CVC to the traffic of glycosylphosphatidylinositol (GPI)-anchored proteins to the plasma membrane of the parasite and promote host invasion. While T. cruzi Rab11 (GFP-TcRab11) localized to the CVC, a dominant negative (DN) mutant tagged with GFP (GFP-TcRab11DN) localized to the cytosol, and epimastigotes expressing this mutant were less responsive to hyposmotic and hyperosmotic stress. Mutant parasites were still able to differentiate into metacyclic forms and infect host cells. GPI-anchored trans-sialidase (TcTS), mucins of the 60–200 KDa family, and trypomastigote small surface antigen (TcTSSA II) co-localized with GFP-TcRab11 to the CVC during transformation of intracellular amastigotes into trypomastigotes. Mucins of the gp35/50 family also co-localized with the CVC during metacyclogenesis. Parasites expressing GFP-TcRab11DN prevented TcTS, but not other membrane proteins, from reaching the plasma membrane, and were less infective as compared to wild type cells. Incubation of these mutants in the presence of exogenous recombinant active, but not inactive, TcTS, and a sialic acid donor, before infecting host cells, partially rescued infectivity of trypomastigotes. Taking together these results reveal roles of TcRab11 in osmoregulation and trafficking of trans-sialidase to the plasma membrane, the role of trans-sialidase in promoting infection, and a novel unconventional mechanism of GPI-anchored protein secretion.     

Synchronized mammalian cell culture: Part II—population ensemble modeling and analysis for development of reproducible processes

The consideration of inherent population inhomogeneities of mammalian cell cultures becomes increasingly important for systems biology study and for developing more stable and efficient processes. However, variations of cellular properties belonging to different sub‐populations and their potential effects on cellular physiology and kinetics of culture productivity under bioproduction conditions have not yet been much in the focus of research. Culture heterogeneity is strongly determined by the advance of the cell cycle. The assignment of cell‐cycle specific cellular variations to large‐scale process conditions can be optimally determined based on the combination of (partially) synchronized cultivation under otherwise physiological conditions and subsequent population‐resolved model adaptation. The first step has been achieved using the physical selection method of countercurrent flow centrifugal elutriation, recently established in our group for different mammalian cell lines which is presented in Part I of this paper series. In this second part, we demonstrate the successful adaptation and application of a cell‐cycle dependent population balance ensemble model to describe and understand synchronized bioreactor cultivations performed with two model mammalian cell lines, AGE1.HN_AAT and CHO‐K1. Numerical adaptation of the model to experimental data allows for detection of phase‐specific parameters and for determination of significant variations between different phases and different cell lines. It shows that special care must be taken with regard to the sampling frequency in such oscillation cultures to minimize phase shift (jitter) artifacts. Based on predictions of long‐term oscillation behavior of a culture depending on its start conditions, optimal elutriation setup trade‐offs between high cell yields and high synchronization efficiency are proposed. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:175–185, 2015     

Brooding in the Chilean Oyster Ostrea chilensis: Unexpected Complexity in the Movements of Brooded Offspring within the Mantle Cavity

Brooding in invertebrates serves to protect embryos from stressful external conditions by retaining progeny inside the female body, effectively reducing the risk of pelagic stages being exposed to predation or other environmental stressors, but with accompanying changes in pallial fluid characteristics, including reduced oxygen availability. Brooded embryos are usually immobile and often encapsulated, but in some Ostrea species the embryos move freely inside the female pallial cavity in close association with the mother’s gills for as long as eight weeks. We used endoscopic techniques to characterize the circulation pattern of embryos brooded by females of the oyster, Ostrea chilensis. Progeny at embryonic and veliger stages typically circulated in established patterns that included the use of dorsal and ventral food grooves (DFG, VFG) to move anteriorly on the gills. Both embryos and veligers accumulated around the mother’s palps, and remained there until an active maternal countercurrent moved them to the gill inhalant area. Both food grooves were able to move embryos, veligers, and food-particle aggregates anteriorly, but the DFG was more important in progeny transport; early embryos were moved more rapidly than veligers in the DFG. A microcirculation pattern of embryos was apparent when they were moved by gill lamellae: when they were close to the VFG, most embryos lost gill contact and ´´fell´´ down to the DFG. Those that actually reached the DFG moved anteriorly, but others came into contact with the base of the lamellae and again moved towards the VFG. The circulation pattern of the progeny appears well-suited for both cleaning them and directing them posteriorly to an area where there is more oxygen and food than in the palp region. This process for actively circulating progeny involves the feeding structures (gill and palps) and appears to be energetically costly for the female. It also interferes with feeding, which could explain the poor energy balance previously documented for brooding females of this species.