Ghrelin immunohistochemistry of gastric adenocarcinoma and mucoepidermoid carcinoma of salivary gland

Ghrelin (G-HH) synthesized in several tissues including salivary and stomach glands stimulates appetite in humans by modulating neuropeptide Y neurons in the hypothalamic arcuate nucleus. Loss of appetite is one of the most important symptoms of stomach cancer. We conducted a study using immunohistochemistry to determine whether salivary glands and stomach cancer tissues produce ghrelin. We determined that negative ghrelin immunohistochemistry discriminates tumors from normal tissues and may therefore further our understanding of the clinically important problem of reduced food intake and anorexia in cancer patients. Radioimmunoassay analyses confirmed that cancer cells do not produce a G-HH peptide, whereas normal cells yield this peptide.     

Specific glycanforms of type IX collagen accumulate in embryonic chick sterna after 17 days of development

Type IX collagen is a key component of the extracellular matrix of cartilage where it occurs at the surfaces of type II collagen fibrils as a glycanated molecule. The function of the glycosaminoglycan (GAG) side chain of the molecule is, however, unknown. We have shown that type IX collagen in chicken sternal cartilage is synthesized with a unimodal distribution of GAG chain size, but at post 17 days of development three predominant glycanforms of type IX collagen accumulate. Such accumulation did not occur in sterna from day 15 embryos. In day 17 embryos predominant glycanforms were found in the caudal region of the sternum. By day 19 of development the three predominant glycanforms are widespread throughout the caudal and cephalic regions. The results indicate that developmental and anatomical changes occur to type IX collagen that depend on the size of the GAG chain attached to the alpha2(IX) chain of the molecule.      

Insights into the structural nature of the transition state in the Kir channel gating pathway

In a previous study we identified an extensive gating network within the inwardly rectifying Kir1.1 (ROMK) channel by combining systematic scanning mutagenesis and functional analysis with structural models of the channel in the closed, pre-open and open states. This extensive network appeared to stabilize the open and pre-open states, but the network fragmented upon channel closure. In this study we have analyzed the gating kinetics of different mutations within key parts of this gating network. These results suggest that the structure of the transition state (TS), which connects the pre-open and closed states of the channel, more closely resembles the structure of the pre-open state. Furthermore, the G-loop, which occurs at the center of this extensive gating network, appears to become unstructured in the TS because mutations within this region have a ‘catalytic’ effect upon the channel gating kinetics.     

Human breast milk stimulates bile acid secretion by fetal rabbit liver in organ culture

Fetal livers from rabbits at 30 days of gestation were grown in organ culture and the effect of human milk added to the culture medium on the ability of liver to excrete bile acids (cholylglycine) was examined. Human breast milk promoted a concentration related increase in cholylglycine accumulation in the medium. The factor(s) present in milk responsible for this effect appear to be non-protein in nature and is associated with the floating lipid fraction. Furthermore, milk enhances the integrity of liver explants, as established by light microscopy.     

Antimicrobial activity of silymarin mediated zinc oxide and hydroxy apatite nanoparticles against oral pathogens

The nanoparticles such as hydroxyapatite, zinc oxide, titanium dioxide and zirconium nanoparticles have application in dentistry. Therefore, it is of interest to document the antimicrobial activity of silymarin mediated zinc oxide and hydroxy apatite nanoparticles against oral pathogens. Hence, we synthesized hydroxyapatie and zinc oxide nanoparticles with silymarin and characterized by UV-visible spectrophotometer. Data shows that silymarin mediated HAP and ZnO nanoparticles have antimicrobial activity against oral pathogens such as Pseudomonas sp, Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis and Candida albicans.     

Short-term effects of 7-ketocholesterol on human adipose tissue mesenchymal stem cells in vitro

Oxysterols comprise a very heterogeneous group derived from cholesterol through enzymatic and non-enzymatic oxidation. Among them, 7-ketocholesterol (7-KC) is one of the most important. It has potent effects in cell death processes, including cytoxicity and apoptosis induction. Mesenchymal stem cells (MSCs) are multipotent cells characterized by self-renewal and cellular differentiation capabilities. Very little is known about the effects of oxysterols in MSCs. Here, we describe the short-term cytotoxic effect of 7-ketocholesterol on MSCs derived from human adipose tissue. MSCs were isolated from adipose tissue obtained from two young, healthy women. After 24 h incubation with 7-KC, mitochondrial hyperpolarization was observed, followed by a slight increase in the level of apoptosis and changes in actin organization. Finally, the IC₅₀ of 7-KC was higher in these cells than has been observed or described in other normal or cancer cell lines.     

The Diversity of Flower Flies (Diptera: Syrphidae) in Colombia and Their Neotropical Distribution

In Colombia, like most Neotropical countries, faunistic studies on flower flies have been occasional and most of them have been primarily focused on taxonomy. Colombia is the second-most species-rich country in flower fly diversity in the Neotropics after Brazil, and has one of the highest numbers of species per unit area (2.49 per 10,000?km²), based on a review of literature and national collections. Including new data presented here, a total of 47 genera and 300 species are recorded in Colombia. The genera Scaeva Fabricius and Lycastrirhyncha Bigot, as well as 101 species are recorded here for the first time. The altitudinal range and the distribution of the flower fly genera in Colombia are presented. A preliminary comparison of the fauna of Colombia with that of other Neotropical countries is given. A historical perspective is also provided in order to illustrate how Colombian Syrphidae knowledge has progressed over the last 168?years. Information presented here will be useful for ongoing and future biodiversity research as well as conservation projects on Syrphidae in the Neotropical region.