Isolation of material displaying insulin-like immunological biological activity from the brain of the blowfly Calliphora vomitoria.

An insulin-like material from the brain of the blowfly Calliphora vomitoria was partially purified by acid alcohol extraction, gel filtration and ion-exchange cellulose chromatography. In addition, the RF value on polyacrylamide-gel electrophoresis was determined. The material was characterized by its ability to cross-react with bovine insulin antibody and by displaying diminished immunoreactivity on dilution. It displaced specifically bound 125I-labelled insulin from rat liver plasma membrane insulin receptors and displayed insulin-like biological activity on the isolated rat fat-cell. Within 30 min of injection into Calliphora, made hypertrehalocaemic and hyperglucaemic as a result of median neurosecretory cell removal, it caused the concentrations of both sugars to return to normal. The hypothesis is put forward that the median neurosecretory cells are the source of the material.     

Conformational Preferences of the CalliFMRFamides and their Free-Acid Analogues

Abstract

A molecular dynamics study was undertaken to determine the conformational basis for the differing activities of the insect neuropeptide hormones calliFMRFamide 3 (SPSQDFMRF-NH₂), calliFMRFamide 5 (APGQDFMRF-NH₂) and their corresponding free-acid analogues (SPSQDFM- RF-OH and APGQDFMRF-OH) in two insect bioassays. A simulated annealing protocol was used to determine the range of conformers available to the linear peptides. Analysis of the conformers obtained indicated that all the peptides exhibited distinct secondary structure preferences. These, when correlated with their biological activities, enabled the formulation of putative conformation- activity relationships for the peptides.     

TAT-BH4 counteracts Abeta toxicity on capillary endothelium

Oxidative stress is one of the factor contributing to blood brain barrier degeneration. This phenomenon is observed during pathological conditions such as Alzheimer's disease or cerebral amyloid angiopathy in which brain haemorrhages are very frequent. Both diseases are characterized by beta amyloid peptide deposition either in neurons or in vessels. Oxidative stress leads to impairment of mitochondrial functions and apoptotic cell death subsequent to caspases activation. In this paper we demonstrate that BH4 domain of Bcl-xl administrated to endothelial cells as the conjugated form with TAT peptide, reverts Abeta-induced apoptotic cell death by activating a survival programme which is Akt/endothelial nitric oxide synthase dependent.     

Epidemiological Panel Studies of Older Adults: New Frontiers in the Research on Human– Animal Interaction

ABSTRACT

This paper discusses epidemiological studies of older adults and human–animal interaction (HAI), and potential relevance to future research on HAI and animal-assisted interventions (AAI) in aging populations. Key issues in epidemiological work are discussed, including target populations, treatment/exposures, follow up, and endpoint measures as they relate to interacting with or owning companion animals. In outlining the limits in our current state of knowledge, we also make recommendations for the design and analysis of epidemiological studies to advance research on HAI and aging.     

Effect of various bud induction treatments on elongation and rooting of adventitious shoots of Canary Island pine (Pinus canariensis)

Three-day-old cotyledonary explants of Pinus canariensis were subjected to 30 induction treatments using half-strength Bornman's medium containing various combinations of N⁶- benzyladenine, zeatin, kinetin and 2-isopentenyl-adenine. The highest numbers of buds were obtained with 10 M 6-benzyladenine, but both kinetin and zeatin influenced shoot elongation. Shoots were maintained on half-strength Schenk and Hildebrandt medium with 2% sucrose and 0.05% activated charcoal. For rooting, shoots were pulsed for 4 h in a 100 M indole-3-butyric acid aqueous solution (pH 4.2–4.5), and planted in peat:vermiculite:perlite (1:1:1). After 8 weeks, the numbers of rooted shoots were similar for most treatments. Therefore, the bud induction treatments did not significantly influence rooting of adventitious shoots of Canary Island pine.     

Cytokinin-induced switch in development in excised cotyledons of radiata pine cultured in vitro

Cotyledons of Pinus radiata D. Don were cultured under shoot-forming (plus cytokinin) and elongating (minus cytokinin) conditions. Using. autoradiographic and precursor incorporation techniques, the sites and rate of macromolecular synthesis were examined during the first five days in culture. Active incorporation of ³H-thymidine, ³ H-uridine and ³H-leucine occurred. In shoot-forming cotyledons the incorporation became preferentially located in the epidermal and sub-epidermal cell layers in contact with the medium. In elongating cotyledons, in contrast, incorporation was randomly distributed, and the amount of incorporation declined with time. Biochemically, differences in DNA, RNA and total protein synthetic patterns were observed. In elongating cotyledons the rates of RNA and protein synthesis were higher during the first 48 h than in shoot-forming tissues, after which the synthetic rates were similar. Two peaks of newly formed DNA were observed in both tissues. These findings indicate that the cytokinin-induced changes in developmental pathways began within 24 h in culture.     

Novel tricyclic indeno[2,1-d]pyrimidines with dual antiangiogenic and cytotoxic activities as potent antitumor agents

We designed, synthesized and evaluated 13 novel tricyclic indeno[2,1-d]pyrimidines as RTK inhibitors. These analogues were synthesized via a Dieckmann condensation of 1,2-phenylenediacetonitrile followed by cyclocondensation with guanidine carbonate to afford the 2-amino-3,9-dihydro-indeno[2,1-d]pyrimidin-4-one. Sulfonation of the 4-position followed by displacement with appropriately substituted anilines afforded the target compounds. These compounds were potent inhibitors of platelet-derived growth factor receptor β (PDGFRβ) and inhibited angiogenesis in the chicken embryo chorioallantonic membrane (CAM) assay compared to standards. In addition, compound 7 had a two digit nanomolar GI(50) against nine tumor cell lines, a submicromolar GI(50) against 29 of other tumor cell lines in the preclinical NCI 60 tumor cell line panel. Compound 7 also demonstrated significant in vivo inhibition of tumor growth and angiogenesis in a B16-F10 syngeneic mouse melanoma model.     

Molecular clocks and geological dates: cytochrome b of Anolis extremus substantially contradicts dating of Barbados emergence

Even though molecular clocks vary in rate to some extent, they are widely used and very important in a range of evolutionary studies, not least in interpreting cause and colonization in phylogeography. Evolutionists may use island age and emergence to give the earliest possible date for colonization by a species and hence give the lower limit in a molecular clock calibration. The geology of the Lesser Antilles is well studied and Barbados, although composed of some ancient rocks, is thought to have emerged only about 1 million years ago (Ma). The cytochrome b mitochondrial gene is the most widely used gene in vertebrate phylogeography, and generally evolves at a rate of 1-2% per million years (Myr) for poikilothermic vertebrates. Divergence measured across almost all of this gene in the endemic anole (Anolis extremus) reveals a mean patristic distance of approximately 8.3% between this clade and its sister, together with distinct divergence and phylogeographical structure within Barbados. The divergence time, estimated by a range of procedures using four calibration points, is not in the least compatible with the proposed geological time of emergence of Barbados. Hence, either the molecular clock rate does not apply to the Barbadian anole population, or the geological dating of the emergence of Barbados is erroneous. The compatibility of geological times and molecular divergence of this complex on Martinique, together with relative rates tests comparing the rates on Barbados and Martinique, do not suggest atypical clock rates. The question of whether Barbados emerged much earlier than is currently thought, or whether the molecular clock assumptions are inappropriate, remains open.