A differential proteomics study of cerebrospinal fluid from individuals with Niemann-Pick disease,Type C1

Niemann-Pick, type C1 (NPC1) is a fatal, neurodegenerative disease, which belongs to the family of lysosomal diseases. In NPC1, endo/lysosomal accumulation of unesterified cholesterol and sphingolipids arise from improper intracellular trafficking resulting in multi-organ dysfunction. With the proximity between the brain and cerebrospinal fluid (CSF), performing differential proteomics provides a means to shed light to changes occurring in the brain. In this study, CSF samples obtained from NPC1 individuals and unaffected controls were used for protein biomarker identification. A subset of these individuals with NPC1 are being treated with miglustat, a glycosphingolipid synthesis inhibitor. Of the 300 identified proteins, 71 proteins were altered in individuals with NPC1 compared to controls including cathepsin D, and members of the complement family. Included are a report of 10 potential markers for monitoring therapeutic treatment. We observed that pro-neuropeptide Y (NPY) was significantly increased in NPC1 individuals relative to healthy controls; however, individuals treated with miglustat displayed levels comparable to healthy controls. In further investigation, NPY levels in a NPC1 mouse model corroborated our findings. We posit that NPY could be a potential therapeutic target for NPC1 due to its multiple roles in the central nervous system such as attenuating neuroinflammation and reducing excitotoxicity.     

Of Ducklings and Turing Machines: Interactive Playbacks Enhance Subsequent Responsiveness to Conspecific Calls

Distress calls of mallard ducklings consist of a highly stereotyped series of notes. When two ducklings are simultaneously separated from the brood, they characteristically call in alternation. Each bird inhibits its calls while the other is vocalizing, thus preventing masking and facilitating localization by the hen. I examined whether exposure of ducklings to calls presented in a naturalistic alternating pattern affected subsequent responsiveness to them. Individual ducklings were exposed to either 40 s or 80 s of computer-controlled distress call playbacks, using an algorithm that mimicked the behavior of another duckling. Calls were presented only when the subject was silent and ended as soon as it began to vocalize. Each of these ducklings was paired with a ‘yoked’ control. Birds in these control groups experienced exactly the same pattern of playbacks as the ‘interactive’ birds, but the stimuli had no consistent relationship to their own vocal behavior. When the same calls were played back 24 h later, in a fixed pattern that was independent of the ducklings' behavior, birds that had received 80 s of prior interactive exposure were significantly more responsive than both their yoked controls and birds receiving only 40 s of such playbacks. This result suggests that interactive vocal experience, characteristic of natural communication, affects the subsequent perceptual sensitivity of ducklings.     

Patterns of parasitism among conopid flies parasitizing bumblebees

The effects of host size and host species on the prevalence and fitness of conopid flies (Diptera: Conopidae) parasitizing bumblebees (Hymenoptera: Apidae) were investigated. Field data from nine sites across south‐western Alberta, Canada, showed that conopids parasitized, on average, 12.3% of workers and 3.5% of male bees. In general, bee mass was a better predictor of host use and conopid offspring size than bee species. Host mass could not, however, explain the very low prevalence of conopids in the long‐tongued bumblebee, Bombus californicus Smith, or in male bees in general. Conopids predominately infested bees of intermediate size, and as a result, occurred most commonly in the intermediately sized species, B. flavifrons Cresson. Host quality, in terms of conopid offspring size, increased as a non‐linear function of bee size. The results are discussed with respect to the impact of conopids on bumblebee populations, and the relation between host quality and patterns of host use.     

Apoptosis of circulating tumor cells in prostate cancer patients.

BACKGROUND: The prescence of circulating tumor cells (CTCs) in the peripheral blood of cancer patients and their frequency has been correlated with disease status. METHODS: In this study, CTCs were characterized by flow cytometry and fluorescence microscopy after immunomagnetic enrichment from 7.5-ml blood samples collected from patients with prostate cancer in evacuated blood-draw tubes that contained an anticoagulant and a preservative. Events were classified as tumor cell candidates if they expressed cytokeratin, lacked CD45, and stained with the nucleic acid dye 4,6-diamidino-2-phenylindole. RESULTS: In the blood of prostate cancer patients, only few of these events were intact cells. Other CTC events appeared as damaged cells or cell fragments by microscopy. By flow cytometry, these events stained variably with 4,6-diamidino-2-phenylindole and frequently expressed the apoptosis-induced, caspase-cleaved cytokeratin 18. Similar patterns of cell disintegration were observed when cells of the prostate line LNCaP were exposed to paclitaxel before spiking the cells into normal blood samples. CONCLUSIONS: The different observed stages of tumor cell degradation or apoptosis varied greatly between patients and were not found in blood of normal donors. Enumeration of CTCs and identification of CTCs undergoing apoptosis may provide relevant information to evaluate the response to therapy in cancer patients.     

A New Genus of Fossil Sand Crab (Anomura: Albuneidae) from the Oligocene of Italy

The recently described fossil albuneid Paralbunea galantensis De Angeli and Marangon differs from the type of the genus Paralbunea Serène and is herein made the type species of a new genus, Harryhausenia , which is closely related to Zygopa Serène and Umali. A discussion is given on the relationships between the new genus and Zygopa , as well as between Zygopa and other albuneid taxa.     

The Problematic Paralbunea Hu and Tao, 1996: Homonymy, Generic Nom. Nov., and Correct Taxonomic Placement

The fossil genus Paralbunea Hu and Tao, described as an anomuran albuneid, is a junior homonym of Paralbunea Serène and a possible synonym of either the brachyuran raninid Ranilia H. Milne Edwards, 1837, or Cosmonotus Adams and White, 1848. The type series of P. taipeiensis Hu and Tao is composed of at least two species belonging to two raninid genera and appears (in part) assignable to the genus Ranilia and (in part) to Cosmonotus grayi Adams and White, 1848. However, due to both limited availability and poor quality of the holotype of Paralbunea taipeiensis , and destruction of the paratypes, this taxon cannot be unequivocally synonymized with any particular raninid taxon and a new name is proposed to replace Hu and Tao's preoccupied generic name. Caution is urged when describing purported albuneid fossils, due to strong convergence with raninid crabs, which are far more common in the fossil record.     

Flow rate and vertical position influence ingestion rates of colonial zebra mussels (Dreissena polymorpha)

1. Zebra mussels aggregate to form dense colonies where, depending on the flow rate, individuals in different vertical locations within the colony may experience restricted food availability. 2. Using ³²P‐labelled Chlamydomonas angulosa, we found ingestion rates of individual mussels located at the surface to exceed those in the bottom of a 6 cm thick colony by up to 75%. 3. Higher velocities (10 and 20 cm s^?1) increased algal delivery to the colony's middle layer (2–4 cm depth), subsequently increasing ingestion rates to equal those in the surface layer, while increasing ingestion only for the smallest mussels in the bottom (4–6 cm). 4. At all vertical locations within the colonies, smaller mussels showed higher ingestion rates per unit mass than larger mussels, particularly at higher flow rates.     

Protein stabilization by compatible solutes. Effect of diglycerol phosphate on the dynamics of Desulfovibrio gigas rubredoxin studied by NMR.

Heteronuclear NMR relaxation measurements and hydrogen exchange data have been used to characterize protein dynamics in the presence or absence of stabilizing solutes from hyperthermophiles. Rubredoxin from Desulfovibrio gigas was selected as a model protein and the effect of diglycerol phosphate on its dynamic behaviour was studied. The presence of 100 mM diglycerol phosphate induces a fourfold increase in the half-life for thermal denaturation of D. gigas rubredoxin. A model-free analysis of the protein backbone relaxation parameters shows an average increase of generalized order parameters of 0.015 reflecting a small overall reduction in mobility of fast-scale motions. Hydrogen exchange data acquired over a temperature span of 20 degrees C yielded thermodynamic parameters for the structural opening reactions that allow for the exchange. This shows that the closed form of the protein is stabilized by an additional 1.6 kJ x mol(-1) in the presence of the solute. The results seem to indicate that the stabilizing effect is due mainly to a reduction in mobility of the slower, larger-scale motions within the protein structure with an associated increase in the enthalpy of interactions.     

Interleukin-6 release from human skeletal muscle during exercise: relation to AMPK activity.

We tested the hypothesis that IL-6 release from muscle during exercise may be related to muscle activity of 5'-AMP-activated protein kinase (AMPK). Eight healthy, well-trained young men completed two 60-min trials on a bicycle ergometer at 70% of their peak oxygen uptake in either a glycogen-depleted or a glycogen-loaded state. IL-6 was released from the leg already after 10 min of exercise in the glycogen-depleted state, whereas no significant release was observed at any time in the loaded state. Nevertheless, plasma IL-6 increased similarly in the two trials from approximately 0.8 pg/ml at rest to approximately 4.5 pg/ml after 60 min of exercise. Activity of alpha1-AMPK (160%) and alpha2-AMPK (145%) was increased at rest in the glycogen-depleted compared with the loaded situation. During exercise, alpha1-AMPK activity did not change from resting levels in both trials, whereas alpha2-AMPK activity increased only in the glycogen-depleted state. After 60 min of exercise in the glycogen-depleted state, individual values of alpha2-AMPK activity correlated significantly (r = 0.87, P < 0.006) with individual values of IL-6 release as well as with average IL-6 release over the entire 60 min (r = 0.86, P < 0.006). The present data are compatible with a role for AMPK in IL-6 release during exercise or a role for IL-6 in activating AMPK. Alternatively, both AMPK and IL-6 are independent sensors of a low muscle glycogen concentration during exercise. In addition, leg release of IL-6 cannot alone explain the increase in plasma IL-6 during exercise.     

Molecular characterization of the lysosomal acid phosphatase fromDrosophila melanogaster

InDrosophila, unlike humans, the lysosomal acid phosphatase (Acph-1) is a non-essential enzyme. It is also one of the most rapidly evolving gene-enzyme systems in the genus. In order to determine which parts of the enzyme are conserved and which parts are apparently under little functional constraint, we cloned the gene fromDrosophila melanogaster via a chromosomal walk. Fragments from the gene were used to recover an apparently full-length cDNA. The cDNA was subcloned into aDrosophila transformation vector where it was under the control of the 5′ promoter sequence of thehsp-70 gene. Three independent transformants were obtained; in each, Acph-1 expression from the cDNA was constitutive and not dependent on heat shock, as determined by densitometric analyses of the allozymic forms of the enzyme. The pattern of expression indicates thehsp-70 and endogenousAcph-1 promoters act together in some, but not all, tissues. The sequence of the cDNA was determined using deletions made with exonuclease III, and primers deduced from the cDNA sequence were used to sequence the genomic clone. Five introns were found, and putative 5′ up-stream regulatory sequences were identified. Amino acid sequence comparisons have revealed several highly conserved motifs betweenDrosophila Acph-1 and vertebrate lysosomal and prostatic acid phosphatases.