NMR analysis of Caenorhabditis elegans FLP-18 neuropeptides: implications for NPR-1 activation

Phe-Met-Arg-Phe-NH2 (FMRFamide)-like peptides (FLPs) are the largest neuropeptide family in animals, particularly invertebrates. FLPs are characterized by a C-N-terminal gradient of decreasing amino acid conservation. Neuropeptide receptor 1 (NPR-1) is a G-protein coupled receptor (GPCR), which has been shown to be a strong regulator of foraging behavior and aggregation responses in Caenorhabditis elegans. Recently, ligands for NPR-1 were identified as neuropeptides coded by the precursor genes flp-18 and flp-21 in C. elegans. The flp-18 gene encodes eight FLPs including DFDGAMPGVLRF-NH2 and EMPGVLRF-NH2. These peptides exhibit considerably different activities on NPR-1, with the longer one showing a lower potency. We have used nuclear magnetic resonance and biological activity to investigate structural features that may explain these activity differences. Our data demonstrate that long-range electrostatic interactions exist between N-terminal aspartates and the C-terminal penultimate arginine as well as N-terminal hydrogen-bonding interactions that form transient loops within DFDGAMPGVLRF-NH2. We hypothesize that these loops, along with peptide charge, diminish the activity of this peptide on NPR-1 relative to that of EMPGVLRF-NH2. These results provide some insight into the large amino acid diversity in FLPs.     

Past and present role of the Indian-fig prickly-pear (Opuntia ficus-indica (L.) Miller,Cactaceae) in the agriculture of sicily

Of prickly-pear cacti occurring in Sicily, the most widespread and economically important isOpuntia ficus-indica (L.) Miller. In Sicily it has, since its introduction, played an important role in the exploitation of marginal areas. The Sicilian experience is described with reference to the historical outlines and the present intensive production of late fruit. Information on historical and actual uses of the plant and its products (flowers, cladodes, fruits) is given.     

Outdoor cultivation ofArthrospira platensis during autumn and winter in temperate climates

Arthrospira (Spirulina) platensis M2 was grown outdoors in 50-mm diameter tubular reactors under the climatic conditions of central Italy (Florence) from September to December 1995 and in March 1996. Except for September, the cultures temperature was regulated. Mean productivities of 0.83, 0.44 and 0.61 g dry wt L^–1 d^–1 were achieved in autumn (September–October), winter (November–December) and March, respectively. In autumn and winter, the photosynthetic efficiency of the cultures and the degree of correlation between productivity and solar irradiance were significantly greater than in summer. The effect of cell density and aeration rate on productivity was evaluated in September. The productivity of cultures operated at high supra-optimal population density was about 30% less at high aeration rate (1.0 LL^–1 min^–1), and 50% less at standard aeration rate (0.17 LL^–1 min^–1), than that of control cultures kept at optimal population density and standard aeration rate. The reduction of productivity in high-density cultures was due to lower daylight output rates and higher night biomass losses (the latter were particularly relevant under standard aeration conditions). The main factor limiting productivity in closed reactors during autumn was the night temperature. Heating the cultures during daylight hours on sunny days did not cause any significant increase of the yields, since under sunlight the unheated cultures also reached the optimal temperature for growth early in the morning. On cloudy days, the day-time temperature of the unheated cultures remained well below the optimum, however this had only a limited effect on productivity since algal growth was mainly light-limited.     

An evaluation of head position and craniofacial reference line variation

Natural head position (NHP) is the usual, balanced position of the head which is adopted for viewing the horizon or an object at eye level. Determination of NHP is useful when reconstructing facial form in art, forensics, orthodontic diagnosis and treatment planning for surgical management of craniofacial dysmorphic conditions. When NHP is uncertain, correction such as orientation to Frankfurt horizontal (FH) has been advocated. However, FH angulation varies between individuals and is subject to landmark identification error. Previous studies have measured FH and other craniofacial planes in relation to the true horizontal (HOR) with subjects in NHP and have found similar variation to that found with FH. This study measured craniofacial planes in 40 Aboriginal Australians (20 male, 20 female, aged 17 years or greater) from lateral cephalographs and compared its results with classical previous studies. Four planes, the neutral horizontal axis (NHA), FH, Krogman-Walker line (KW line), and palatal plane (P plane) demonstrated near parallelism and averaged between −1° and −2° from HOR. The combined use of NHA, FH, KW line, and P plane enables more effective corrected head position (CHP).     

Synthesis and biological evaluation of 1,7,8,8a-tetrahydro-3H-oxazolo[3,4-a]pyrazin-6(5H)-ones as antitumoral agents

A series of 1,7,8,8a-tetrahydro-3H-oxazolo[3,4-a]pyrazin-6(5H)-ones has been synthesized by an intramolecular, palladium(II) catalyzed, aminooxygenation of alkenyl ureas, readily available from glycine allylamides as starting materials. Biological tests showed that the obtained compounds are endowed with an interesting antitumoral activity against two human thyroid cancer cell lines, namely FTC-133 and 8305C, by promoting the apoptotic pathway and DNA fragmentation.     

Species accumulation over space and time in European Plio-Holocene mammals

The rate of increase in species number with sampled area is one issue of major interest in ecology. Species number increases with sampled time as well, though this kind of analysis is much rarer in literature. Species-area and species-time relationships have been recently integrated in a single model, which allows studying how time and area interact with each other in determining the cumulative increase in species richness. Here we studied species-area, species-time, and species-time-area relationships in Plio-Holocene large mammals of Western Eurasia, by using an extensive database including 184 species distributed in 685 fossil sites. We found that the increase of species number with time is much higher than with area. When sampling inequality of fossil localities in time and space is accounted for, time and area interact with each other in a negative, though non-linear fashion. The intense climatic changes that characterized the Plio-Holocene period apparently affected both species-area and species-time relationships in large mammals, by increasing the slope of the former during the Pliocene and middle Pleistocene, and of the latter during younger, climatically harsher, late Pleistocene times. This study emphasizes the importance of accounting for time and space in tracing paleodiversity curves.     

Thyroid hormone profiles in goitrous and non-goitrous subjects seen in an endemic goiter area of the Central African Republic]

In the present study T3, T4, TSH serum concentrations were measured in 166 subjects whose goiter grading was ascertained according to WHO classification; 39 of them had no goiter (grading 0), 127 were goitrous with a grading comprised between 1a and 4. The two samples were composed by Males and Females of various ages whose choice was strictly predetermined by random numbers. The median ages of 127 goitrous and 39 non goitrous subjects were respectively 23.5 years and 33.5 years; 30 Males and 5 Females were in the first group; 58 Males and 69 Females in the second. They lived in the Ouham region of Centro African Republic where some of the Authors ascertained a severe goiter endemia due to iodine deficiency and manioc consumption as staple food. All the values of T4 and TSH of the two group of subjects, were significantly different from the control values (p less than 0.01) excepting T3. Goitrous subjects had T4 value lower than non goitrous subjects (p less than 0.05). The subjects of each group were distributed in the four subsequent subgroups: A) with T3, T4, TSH in the normal range; B) with elevated TSH and T3 and T4 in normal range; C) with elevated TSH, subnormal T4, and T3 in normal range; D) with elevated TSH and subnormal T3 and T4. From fig. 1 it can be seen that the 79.5% of goitrous subjects had a supranormal TSH (subgroups B + C + D) and 40.7% of them had a subnormal T4 (subgroups C + D).(ABSTRACT TRUNCATED AT 250 WORDS)