Vibrational spectroscopy and chemometrics to characterize and quantitate trehalose crystallization

Investigating the phase behavior of sugars in ice and lyophilized solids is of significant interest in the pharmaceutical industry. In this study, Raman and near infrared (NIR) spectroscopy are used to characterize and quantitate trehalose crystallization using several chemometric models. The predictive behaviors of partial least squares (PLS), principal component analysis (PCA), and multiple linear regression (MLR) models are compared. In general, PLS and PCA outperform linear and MLR models. Changes in specific vibrational modes associated with several coupled motions are described and assigned as a function of crystal content. In addition to characterization and quantitation, our method may be used to localize gradients of amorphous and/or crystallized trehalose within a sample.     

1-Arylpiperazinyl-4-cyclohexylamine derived isoindole-1,3-diones as potent and selective alpha-1a/1d adrenergic receptor ligands

Subtype-selective alpha-1a and/or alpha-1d adrenergic receptor antagonists may be useful for the treatment of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) with fewer adverse effects than non-selective drugs. A series of 1-arylpiperazinyl-4-cyclohexylamine derived isoindole-1,3-diones has been synthesized, displaying in vitro alpha(1a) and alpha(1d) binding affinity K(i) values in the range of 0.09-38nM with K(i)(alpha1b)/K(i)(alpha1a) and K(i)(alpha1b)/K(i)(alpha1d) selectivity ratios up to 3607-fold.     

Influence of landscape structure on endemic cicadas in New Zealand kiwifruit orchards

• 1 The endemic cicada species Amphipsalta cingulata (Fabricius) and Amphipsalta zelandica (Boisduval) are pests of New Zealand kiwifruit.
• 2 We determined the abundance of A. cingulata and A. zelandica by counting final‐instar exuviae in a block of ‘Hayward’ kiwifruit, the dominant cultivar, on each of 70 blocks on separate orchards in the Bay of Plenty, New Zealand.
• 3 We used a geographic information system and fragstats to generate predictive variables describing landscape structure in four nested landscapes ranging in size between 6.25 and 400 ha for each site. Other variables described the physical characteristics of the site and management practices. Data were analyzed by boosted regression trees, a method that combines the advantages of regression trees and machine learning.
• 4 The most influential variables differed for each species. Modified coastal landscapes with high densities of ‘Hayward’ kiwifruit were most favourable for A. cingulata. For A. zelandica, favourable landscapes contained significant areas of native forest. The 12 most influential variables accounted for 51% and 46% of the total influence of all variables measured for A. cingulata and A. zelandica, respectively.
• 5 Landscape structure was more influential than insecticide use and local site factors. Despite the apparent low vagility of cicadas, landscape structure at relatively large scales of ≥25 ha was influential for both A. cingulata and A. zelandica. The ability to use a wide range of hosts within the production landscape may account for this pattern. Key variables need to be confirmed by identifying the same patterns in other landscapes.

     

1-(3,4-Dihydroxy-5-Methoxyphenyl-3-Methylbut-2-Ene from The Liverworth Plagiochila Rutilans

Extraction of the liverwort Plagiochila rutilans afforded 1-(3,4-dihydroxy-5-methoxyphenyl)3-methylbut-2-ene, the structure of which was confirmed by synthesis.     

An investigation into the role of Bcl-2 in neuroendocrine differentiation

INTRODUCTION: In addition to its role in apoptosis suppression, Bcl-2 has been reported to be co-expressed with neuroendocrine markers in several tissues, leading to speculation that this oncoprotein may promote neuroendocrine differentiation. AIM: This study investigated whether Bcl-2 modulated neuroendocrine biopeptide expression. METHODS: Levels of chromogranin A, neurone specific enolase, protein gene peptide 9.5, pancreatic polypeptide, and the chromogranin-derived peptides, intervening peptide and vasostatin-1 were examined by immunocytochemistry in rat phaeochromocytoma (PC12) cell lines genetically engineered to over-express Bcl-2 and their mock-transfected controls. Intensity of fluorescence was graded using a semi-quantitative scale from (-) indicating negative expression to (+++) indicating intense positivity. RESULTS: Mann-Whitney U analysis indicated that no significant differences in expression existed between control and Bcl2 over-expressing cell lines for any of the six peptides examined. CONCLUSIONS: The results of this study do not support the hypothesis that Bcl-2 promotes the acquisition of a neuroendocrine phenotype.     

Purification of normal cellular prion protein from human platelets and the formation of a high molecular weight prion protein complex following platelet activation

A method for the extraction and purification of PrP(C), in its native monomeric form, from outdated human platelet concentrates is described. Both calcium ionophore platelet activation and lysis in Triton X-100 were evaluated as methods for the extraction of soluble platelet PrP(C) in its monomeric form. Following platelet activation, the majority of released PrP(C) was detected as a disulphide linked high molecular weight complex, which under reducing conditions could be separated into what appear to be stable non-disulphide linked PrP dimers or PrP covalently linked to another as yet unidentified protein. This phenomenon appears to be unique to activation since only monomeric PrP(C) was detected following lysis of resting platelets. Subsequently, PrP(C) was purified from the Triton X-100 lysate by sequential cation ion exchange and Cu2+ affinity chromatography. From 10 L of outdated platelet concentrate, we were able to recover 1.29 mg PrP(C) at a purity of 92%.     

Membrane localization of v-ErbB is required but not sufficient for ligand-independent transformation

The v-ErbB retroviral oncogene is a transduced, mutated copy of the avian EGF receptor gene, and its expression is sufficient to induce tumor formation in vivo. The structural alterations that release the oncogenic potential of the v-ErbB oncogene are similar to EGFR gene mutations described in human tumors. Thus, the study of v-ErbB tumor biology offers a useful model through which we can gain insight into the mechanism of EGFR-induced malignancies. Despite years of study, however, questions remain regarding the domains of v-ErbB required for oncogenicity. We sought to clarify the role of the transmembrane domain of v-ErbB during transformation using S3-v-ErbB, an acutely transforming retroviral oncogene isolated from avian sarcomas. Infection of primary fibroblasts with a retroviral vector containing S3-v-ErbB results in the formation of a transformation-associated phosphoprotein signaling complex, soft agar colony formation, and the rapid induction of highly vascularized sarcomas in vivo. To address contribution of the transmembrane domain of S3-v-ErbB during these processes, we constructed a mutant version of this oncogene with a precise deletion in this domain. Specifically, the S3-v-ErbB-TM- mutant was created through an in-frame deletion of the entire transmembrane domain. Primary fibroblasts expressing this S3-v-ErbB-TM- mutant fail to form a characteristic transformation-associated phosphoprotein complex and do not grow in an anchorage-independent manner. In addition, day-old chicks injected with a helper-independent retrovirus expressing the S3-v-ErbB-TM- mutant exhibit only limited tumor formation in vivo. These results demonstrate that the transmembrane domain and, consequently membrane localization, are essential for S3-v-ErbB-mediated transformation.     

Genetic inactivation of prohormone convertase (PC1) causes a reduction in cholecystokinin (CCK) levels in the hippocampus, amygdala, pons and medulla in mouse brain that correlates with the degree of colocalization of PC1 and CCK mRNA in these structures in rat brain

Prohormone convertase (PC1) is found in endocrine cell lines that express cholecystokinin (CCK) mRNA and process pro CCK to biologically active products. Other studies have demonstrated that PC1 may be a one of the enzymes responsible for the endoproteolytic cleavages that occur in pro CCK during its biosynthesis and processing. Prohormone convertase 1 (PC1) has a distribution that is similar to cholecystokinin (CCK) in rat brain. A moderate to high percentage of CCK mRNA-positive neurons express PC1 mRNA. CCK levels were measured in PC1 knockout and control mice to assess the degree to which loss of PC1 changed CCK content. CCK levels were decreased 62% in hippocampus, 53% in amygdala and 57% in pons-medulla in PC1 knockout mice as compared to controls. These results are highly correlated with the colocalization of CCK and PC1. The majority of CCK mRNA-positive neurons in the pyramidal cell layer of the hippocampus express PC1 mRNA and greater than 50% of CCK mRNA-positive neurons in several nuclei of the amygdala also express PC1. These results demonstrate that PC1 is important for CCK processing. PC2 and PC5 are also widely colocalized with CCK. It may be that PC2, PC5 or another non-PC enzyme are able to substitute for PC1 and sustain production of some amidated CCK. Together these enzymes may represent a redundant system to insure the production of CCK.     

Sulfur stable isotopes separate producers in marine food-web analysis

Ecological applications of stable isotope analysis rely on different producers having distinct isotopic ratios to trace energy and nutrient transfer to consumers. Carbon (C) and nitrogen (N) are the usual elements analysed. We tested the hypothesis that producers unable to be separated using C and N would be separated by sulphur (S), by reviewing estuarine and marine food web studies using all three elements (total of 836 pairwise comparisons between producers). S had a wider range of values across all producers than C and N (S: 34.4, C: 23.3, N: 18.7), and a higher mean difference among producers (S: 9.3, C: 6.5, N: 3.3). We varied from 1 to 10 the distance producers must be apart to be considered separate. For each of these gap distances, S-separated producers tied on C and N in 40% or more of cases. Comparing the three elements individually, S had fewer tied pairs of producers for any gap distance than C or N. However, S also has higher within-producer variability. Statistical tests on simulated data showed that this higher variability caused S to be less effective than C for analysing differences among mean producer values, yet mixing models showed that S had the smallest confidence intervals around mean estimates of source contributions to consumers. We also examined the spatial and temporal scales over which S isotope signatures of the saltmarsh plant Spartina alterniflora varied. Differences between samples taken within tens of metres were smallest, but between samples hundreds of metres apart were as different as samples thousands of kilometres apart. The time between samples being taken did not influence S signatures. Overall, the use of S is recommended because it has a high probability of distinguishing the contribution of different producers to aquatic food webs. When two elements are employed, the combination of S and C separates more producers than any other combination.