Population size and breeding performance of the Lanner Falcon Falco biarmicus in Sicily: conservation implications

Capsule: We report a significant reduction in population size and breeding success for the Lanner Falcon Falco biarmicus in Sicily, its biggest stronghold in Europe, since the latest coordinated survey.

Aims: To provide updated information on current population size of Lanner Falcon in Sicily and to compare breeding parameters with those obtained in previous studies.

Methods: We performed an intensive coordinated field survey and literature review of breeding success parameters across the species range.

Results: Overall, we monitored 126 territories throughout Sicily where the species had been reported in the last 15 years. Lanner Falcons were present only in 60 of them. Mean nest productivity (± standard deviation) was 1.09?±?1.18 fledged young/checked pairs, flight rate was 2.22?±?0.52 fledged young/successful pairs and breeding success was 49.0%.

Conclusions: Indirect measures aimed at preventing abandonment of occupied territories should be applied, for instance by developing a network of priority areas and slowing down degradation of the pseudo-steppe habitats by agri-environmental schemes. Additionally, direct measures aimed at preventing nest robbery, including the organization of nest guarding activities, and reduction of anthropogenic disturbance and illegal shooting, must be encouraged in order to avoid territory abandonment.     

Variation in heat shock proteins within tropical and desert species of poeciliid fishes

The 70-kilodalton heat shock protein (hsp70) family of molecular chaperones, which contains both stress-inducible and normally abundant constitutive members, is highly conserved across distantly related taxa. Analysis of this protein family in individuals from an outbred population of tropical topminnows, Poeciliopsis gracilis, showed that while constitutive hsp70 family members showed no variation in protein isoforms, inducibly synthesized hsp70 was polymorphic. Several species of Poeciliopsis adapted to desert environments exhibited lower levels of inducible hsp70 polymorphism than the tropical species, but constitutive forms were identical to those in P. gracilis, as they were in the confamilial species Gambusia affinis. These differences suggest that inducible and constitutive members of this family are under different evolutionary constraints and may indicate differences in their function within the cell. Also, northern desert species of Poeciliopsis synthesize a subset of the inducible hsp70 isoforms seen in tropical species. This distribution supports the theory that ancestral tropical fish migrated northward and colonized desert streams; the subsequent decrease in variation of inducible hsp70 may have been due to genetic drift or a consequence of adaptation to the desert environment. Higher levels of variability were found when the 30- kilodalton heat shock protein (hsp30) family was analyzed within different strains of two desert species of Poeciliopsis and also in wild-caught individuals of Gambusia affinis. In both cases the distribution of hsp30 isoform diversity was similar to that seen previously with allozyme polymorphisms.      

柠檬酸合酶的分子生物学研究进展

柠檬酸合酶（citrate synthase,CS）是细胞内多种重要代谢途径的关键酶。CS可催化草酰乙酸和乙酰辅酶A之间的缩合反应生成柠檬酸和辅酶A。通常革兰氏阳性细菌、古菌以及真核细胞的CS为同源二聚体,而革兰氏阴性细菌的CS为同源六聚体。根据其在细胞内的定位不同,CS可分为线粒体CS、乙醛酸循环体CS、过氧化物酶体CS。这些同工酶在能量代谢、植物脂肪的代谢、脂肪酸的氧化及细胞解毒过程中起着重要作用。不同来源的CS空间结构、催化机制和动力学性质十分相似。针对其生化特性、空间结构特点、催化机制以及分子进化等研究进展进行综述。     

Optimising the clinical strategy for autoimmune liver diseases: Principles of value-based medicine

Background

Autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis represent the three major autoimmune liver diseases (AILDs). Their management is highly specialized, requires a multidisciplinary approach and often relies on expensive, orphan drugs. Unfortunately, their treatment is often unsatisfactory, and the care pathway heterogeneous across different centers. Disease-specific clinical outcome indicators (COIs) able to evaluate the whole cycle of care are needed to assist both clinicians and administrators in improving quality and value of care. Aim of our study was to generate a set of COIs for the three AILDs. We then prospectively validated these indicators based on a series of consecutive patients recruited at three tertiary clinical centers in Lombardy, Italy.

The truncated hemoglobin from Mycobacterium leprae

Truncated hemoglobins (trHb's) form a family of low molecular weight O2 binding hemoproteins distributed in eubacteria, protozoa, and plants. TrHb's branch in a distinct clade within the hemoglobin (Hb) superfamily. A unique globin gene has recently been identified from the complete genome sequence of Mycobacterium leprae that is predicted to encode a trHb (M. leprae trHbO). Sequence comparison and modelling considerations indicate that monomeric M. leprae trHbO has structural features typical of trHb's, such as 20-40 fewer residues than conventional globin chains, Gly-based sequence consensus motifs, likely assembling into a 2-on-2 alpha-helical sandwich fold, and hydrophobic residues recognized to build up the protein matrix ligand diffusion tunnel. The ferrous heme iron atom of deoxygenated M. leprae trHbO appears to be hexacoordinated, like in Arabidopsis thaliana trHbO-3 (A. thaliana trHbO-3). Accordingly, the value of the second-order rate constant for M. leprae trHbO carbonylation (7.3 x 10(3) M(-1) s(-1)) is similar to that observed for A. thaliana trHbO-3 (1.4 x 10(4) M(-1) s(-1)) and turns out to be lower than that reported for carbon monoxide binding to pentacoordinated Mycobacterium tuberculosis trHbN (6.7 x 10(6) M(-1) s(-1)). The lower reactivity of M. leprae trHbO as compared to M. tuberculosis trHbN might be related to the higher susceptibility of the leprosy bacillus to toxic nitrogen and oxygen species produced by phagocytic cells.     

Validation of an in vitro screen for phospholipidosis using a high-content biology platform

Several cationic amphiphilic drugs cause local or systemic phospholipidosis (PLD) after chronic exposure in preclinical species. PLD is characterized by the accumulation of drug, phospholipid, and concentric lamellar bodies in cellular lysosomes. We have developed a fluorescence-based in vitro screen that is predictive of PLD using the Cellomics ArrayScan high-content screening platform, which captures and analyzes images from 96-well cell culture microtiter plates using multichannel fluorescence microscopy. I-13.35 adherent mouse spleen macrophage cells were cultured with drug and a fluorescently tagged phospholipid, N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (NBD-PE). Drug concentrations were used in a range from 1 to $100 μmol/L. After 24 h incubations, the cells were fixed with formalin. NBD-PE uptake was quantified in controls and treated cells. Nuclei were identified by Hoechst 33258 staining and dead cells were identified using ethidium homodimer-2 incorporation. Thus, confounding accumulation of NBD-PE due to cytotoxicity that produces false-positive results at high concentrations was eliminated from quantitation by ethidium staining and employing cell gating (dead cell rejection). The assay was found to be both sensitive and selective in that 26 of 28 positive, phospholipidogenic controls and 8 of 8 negative, nonphospholipidogenic controls were correctly called.     

Ligand- and proton-linked conformational changes of the ferrous 2/2 hemoglobin of Pseudoalteromonas haloplanktis TAC125

The spectroscopic and ligand-binding properties of a 2/2 globin from the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125 have been studied in the ferrous state. It displays two major conformations characterized by CO-association rates that differ by a factor of 20, with relative fractions that depend on pH. A dynamic equilibrium is found between the two conformations, as indicated by an enhanced slower phase when lower CO levels were used to allow a longer time to facilitate the transition. The deoxy form, in the absence of external ligands, is a mixture of a predominant six-coordinate low spin form and a five-coordinate high-spin state; the proportion of low spin increasing at alkaline pH. In addition, at temperatures above the physiological temperature of 1 °C, an enhanced tendency of the protein to oxidize is observed.