Radiochemical and radiobiological assessment of a pyridyl-S-cysteine functionalized bombesin derivative labeled with the 99mTc(CO)3+ core

Bombesin is a neuropeptide widely studied due to its ability to target various types of cancers. Technetium-99m on the other hand is ideal for diagnostic tumor targeting. The aim of the present study is the investigation of the coupling of the ligand (S)-(2-(2′-pyridyl)ethyl)-d,l-cysteine with the BN-peptide Gln-Arg-Leu-Gly-Asn-Gln-Trp-Ala-Val-Gly-His-Leu-Met(CONH₂) through the spacer aminohexanoic acidand the labeling of the resulting derivative MBN with the synthon [M(CO)₃(H₂O)₃]⁺ (M = ^99mTc, Re). The peptide was synthesized according to the SPPS method, purified and characterized by ESI-MS. The new ^99mTc-labeled biomolecule was stable in vitro, showed high affinity for the human GRP receptor expressed in PC3 cells and the rate of internalization was found to be time-dependent tissue distribution of the radiopeptide was evaluated in normal mice and in prostate cancer experimental models and significant radioactivity uptake was observed in the pancreas of normal mice as well as in PC3 tumors. Dynamic studies of the radiopeptide showed satisfactory tumor images.     

An Analysis of Pregnancy-Related Mortality in the KEMRI/CDC Health and Demographic Surveillance System in Western Kenya

Background

Pregnancy-related (PR) deaths are often a result of direct obstetric complications occurring at childbirth.

Methods and Findings

To estimate the burden of and characterize risk factors for PR mortality, we evaluated deaths that occurred between 2003 and 2008 among women of childbearing age (15 to 49 years) using Health and Demographic Surveillance System data in rural western Kenya. WHO ICD definition of PR mortality was used: “the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the cause of death”. In addition, symptoms and events at the time of death were examined using the WHO verbal autopsy methodology. Deaths were categorized as either (i) directly PR: main cause of death was ascribed as obstetric, or (ii) indirectly PR: main cause of death was non-obstetric. Of 3,223 deaths in women 15 to 49 years, 249 (7.7%) were PR. One-third (34%) of these were due to direct obstetric causes, predominantly postpartum hemorrhage, abortion complications and puerperal sepsis. Two-thirds were indirect; three-quarters were attributable to human immunodeficiency virus (HIV/AIDS), malaria and tuberculosis. Significantly more women who died in lower socio-economic groups sought care from traditional birth attendants (p = 0.034), while less impoverished women were more likely to seek hospital care (p = 0.001). The PR mortality ratio over the six years was 740 (95% CI 651–838) per 100,000 live births, with no evidence of reduction over time (χ² linear trend = 1.07; p = 0.3).

Conclusions

These data supplement current scanty information on the relationship between infectious diseases and poor maternal outcomes in Africa. They indicate low uptake of maternal health interventions in women dying during pregnancy and postpartum, suggesting improved access to and increased uptake of skilled obstetric care, as well as preventive measures against HIV/AIDS, malaria and tuberculosis among all women of childbearing age may help to reduce pregnancy-related mortality.     

Western myall groves (Acacia papyrocarpa) determine the fine‐scale distribution of soil Collembola in semi‐arid South Australia

Vegetation can exert a strong influence on the distribution and activity of biotic communities across a broad range of spatial scales, especially in arid and semi‐arid ecosystems. At fine spatial scales, patches created by individual plants can support different faunal and floral communities even at locations distant from the plant. These differences can have profound effects on a range of ecosystem processes, including seed dispersal, nutrient cycling and resource distribution. In semi‐arid Australia, areas surrounding groves of western myall (Acacia papyrocarpa) trees are largely devoid of vegetation, being referred to as ‘halos’. Here, we investigate the soil‐dwelling Collembola in groves of western myall trees, the surrounding halos and nearby chenopod shrubland. We also investigated whether the abundance of Collembola was influenced by soil depth (0–5 cm layer vs. 6–10 cm layer) in groves. We found that collembolan density was approximately nine times lower and taxonomic richness half that in a halo compared with the grove and chenopod vegetation. Furthermore, analyses at finer taxonomic levels indicate that vegetation patches differed in species composition, with some species restricted to or preferring particular patches. In the grove, we found a higher abundance of Collembola in the 0–5 cm soil layer compared with the 6–10 layer. Our results indicate vegetation patches strongly influence collembolan abundance and species composition in bare patches around western myall. As patches created by vegetation are a common feature of semi‐arid and arid regions, we suspect that these effects are widespread although seldom reported. Furthermore, as Collembola are involved in the decomposition process, Acacia papyrocarpa patches will be influencing nutrient cycling through their effects on the soil biota. Our results also emphasize that comprehensive fauna survey and management of woodland ecosystems need to consider fine‐scale processes.     

Inhibition of the dopamine D1 receptor signaling by PSD-95

Dopamine D1 receptors play an important role in movement, reward, and learning and are implicated in a number of neurological and psychiatric disorders. These receptors are concentrated in dendritic spines of neurons, including the spine head and the postsynaptic density. D1 within spines is thought to modulate the local channels and receptors to control the excitability and synaptic properties of spines. The molecular mechanisms mediating D1 trafficking, anchorage, and function in spines remain elusive. Here we show that the synaptic scaffolding protein PSD-95 thought to play a role in stabilizing glutamate receptors in the postsynaptic density, interacts with D1 and regulates its trafficking and function. Interestingly, the D1-PSD-95 interaction does not require the well characterized domains of PSD-95 but is mediated by the carboxyl-terminal tail of D1 and the NH(2) terminus of PSD-95, a region that is recognized only recently to participate in protein-protein interaction. Co-expression of PSD-95 with D1 in mammalian cells inhibits the D1-mediated cAMP accumulation without altering the total expression level or the agonist binding properties of the receptor. The diminished D1 signaling is mediated by reduced D1 expression at the cell surface as a consequence of an enhanced constitutive, dynamin-dependent endocytosis. In addition, genetically engineered mice lacking PSD-95 show a heightened behavioral response to either a D1 agonist or the psychostimulant amphetamine. These studies demonstrate a role for a glutamatergic scaffold in dopamine receptor signaling and trafficking and identify a new potential target for the modulation of abnormal dopaminergic function.     

Expression studies of the core+1 protein of the hepatitis C virus 1a in mammalian cells. The influence of the core protein and proteasomes on the intracellular levels of core+1

Recent studies have suggested the existence of a novel protein of hepatitis C virus (HCV) encoded by an ORF overlapping the core gene in the +1 frame (core+1 ORF). Two alternative translation mechanisms have been proposed for expression of the core+1 ORF of HCV-1a in cultured cells; a frameshift mechanism within codons 8-11, yielding a protein known as core+1/F, and/or translation initiation from internal codons in the core+1 ORF, yielding a shorter protein known as core+1/S. To date, the main evidence for the expression of this protein in vivo has been the specific humoral and cellular immune responses against the protein in HCV-infected patients, inasmuch as its detection in biopsies or the HCV infectious system remains elusive. In this study, we characterized the expression properties of the HCV-1a core+1 protein in mammalian cells in order to identify conditions that facilitate its detection. We showed that core+1/S is a very unstable protein, and that expression of the core protein in addition to proteosome activity can downregulate its intracellular levels. Also, we showed that in the Huh-7/T7 cytoplasmic expression system the core+1 ORF from the HCV-1 isolate supports the synthesis of both the core+1/S and core+1/F proteins. Finally, immunofluorescence and subcellular fractionation analyses indicated that core+1/S and core+1/F are cytoplasmic proteins with partial endoplasmic reticulum distribution in interphase cells, whereas in dividing cells they also localize to the microtubules of the mitotic spindle.     

Effect of various process parameters on morphology, rheology, and polygalacturonase production by Aspergillus sojae in a batch bioreactor

The effects of pH, agitation speed, and dissolved oxygen tension (DOT), significant in common fungal fermentations, on the production of polygalacturonase (PG) enzyme and their relation to morphology and broth rheology were investigated using Aspergillus sojae in a batch bioreactor. All three factors were effective on the response parameters under study. An uncontrolled pH increased biomass and PG activity by 27% and 38%, respectively, compared to controlled pH (pH 6) with an average pellet size of 1.69 +/- 0.48 mm. pH did not significantly affect the broth rheology but created an impact on the pellet morphology. Similarly, at constant agitation speed the maximum biomass obtained at 500 rpm and at 30 h was 3.27 and 3.67 times more than at 200 and 350 rpm, respectively, with an average pellet size of 1.08 +/- 0.42 mm. The maximum enzyme productivity of 0.149 U mL-1 h-1 was obtained at 200 rpm with an average pellet size of 0.71 +/- 0.35 mm. Non-Newtonian and pseudoplastic broth rheology was observed at 500 rpm agitation speed, broth rheology exhibited dilatant behavior at the lower agitation rate (200 rpm), and at the medium agitation speed (350 rpm) the broth was close to Newtonian. Furthermore, a DOT range of 30-50% was essential for maximum biomass formation, whereas only 10% DOT was required for maximum PG synthesis. Non-Newtonian shear thickening behavior (n > 1.0) was depicted at DOT levels of 10% and 30%, whereas non-Newtonian shear thinning behavior (n < 1.0) was dominant at 50% DOT. The overall fermentation duration (50-70 h) was considerably shorter compared to common fungal fermentations, revealing the economic feasibility of this particular process. As a result this study not only introduced a new strain with a potential of producing a highly commercially significant enzyme but also provided certain parameters significant in the design and mathematical modeling of fungal bioprocesses.     

Liquid serial dilution is inferior to solid media for isolation of cultures representative of the phylum-level diversity of soil bacteria

Representatives of only four well-characterized bacterial phyla were isolated from a pasture soil by using liquid serial dilution culture. In contrast, members of Acidobacteria, Verrucomicrobia, and Gemmatimonadetes and of other poorly represented bacterial lineages were isolated in earlier experiments with solidified versions of the same media. We conclude that, contrary to expectation, liquid serial dilution culture is inferior to culturing on solid media for isolating representatives of many bacterial phyla from soil.     

Human pregnancy: the role of chemokine networks at the fetal-maternal interface

Chemokines are multifunctional molecules initially described as having a role in leukocyte trafficking and later found to participate in developmental processes such as differentiation and directed migration. Similar events occur in pregnancy during development of the fetal-maternal interface, where there is extensive leukocyte trafficking and tissue morphogenesis, and this is accompanied by abundant chemokine expression. The relationship between chemokines, leukocytes and placental development is beginning to be delineated. During pregnancy a specialised population of maternal leukocytes infiltrates the implantation site. These leukocytes are thought to sustain the delicate balance between protecting the developing embryo/fetus and tolerating its hemiallogeneic tissues. A network of chemokine expression by both fetal and maternal components in the pregnant uterus functions in establishing this leukocyte population. Intriguingly, experiments investigating immune cell recruitment revealed the additional possibility that chemokines influence aspects of placental development. Specifically, cytotrophoblasts, the effector cells of the placenta, express chemokine receptors that can bind ligands found at key locations, implicating chemokines as regulators of cytotrophoblast differentiation and migration. Thus, as in other systems, at the fetal-maternal interface chemokines might regulate multiple functions.