Chronobiological Analysis of Sudden Death Observed in an Emergency Department

The objective of this study was to evaluate the epidemiological characteristics of sudden death (S.D.), with particular reference to the presence of chronobiological rhythms. One hundred eighty-five fatal events were observed during one solar year at the Emergency Department of a northern Italian town. Twenty-three cases were due to accidents or violence, while the remaining 162 corresponded to the operative definition of S.D. we adopted. Investigation by autopsy permitted to recognize that 36% of total deaths were due to cardiovascular diseases (in 2/3 of the cases secondary to ischemic heart diseases). A significant circadian periodicity was observed in S.D. (p=0.01, with two peaks, at 9.26 a.m. and 9.26 p.m.) and also a circannual rhythm, peaking in late autumnDearly winter (p=0.036). The latter was particularly evident in elderly people. A relationship with cardiovascular event rate (of which S.D. recalls the circadian periodicity) is a plausible explanation, while the frequent occurrence of respiratory distress during winter may be at least partly responsible for the high incidence of unexpected deaths seen in this period of the year.     

The proteome of neurofilament-containing protein aggregates in blood

Protein aggregation in biofluids is a poorly understood phenomenon. Under normal physiological conditions, fluid-borne aggregates may contain plasma or cell proteins prone to aggregation. Recent observations suggest that neurofilaments (Nf), the building blocks of neurons and a biomarker of neurodegeneration, are included in high molecular weight complexes in circulation. The composition of these Nf-containing hetero-aggregates (NCH) may change in systemic or organ-specific pathologies, providing the basis to develop novel disease biomarkers. We have tested ultracentrifugation (UC) and a commercially available protein aggregate binder, Seprion PAD-Beads (SEP), for the enrichment of NCH from plasma of healthy individuals, and then characterised the Nf content of the aggregate fractions using gel electrophoresis and their proteome by mass spectrometry (MS). Western blot analysis of fractions obtained by UC showed that among Nf isoforms, neurofilament heavy chain (NfH) was found within SDS-stable high molecular weight aggregates. Shotgun proteomics of aggregates obtained with both extraction techniques identified mostly cell structural and to a lesser extent extra-cellular matrix proteins, while functional analysis revealed pathways involved in inflammatory response, phagosome and prion-like protein behaviour. UC aggregates were specifically enriched with proteins involved in endocrine, metabolic and cell-signalling regulation. We describe the proteome of neurofilament-containing aggregates isolated from healthy individuals biofluids using different extraction methods.     

A dark shell hiding great variability: a molecular insight into the evolution and conservation of melanic Daphnia populations in the Alps

Zooplanktonic microcrustaceans of the Daphnia pulex group appear highly differentiated at high altitudes as a result of alternative colonizations and quick local adaptation to harsh environments. In particular, the occurrence of deeply differentiated mountain lineages of European Daphnia pulicaria (EuPC) is highly related to glacial advances and retreats during the Pleistocene. Nowadays, one single ancient EuPC lineage survives in the Pyrenees, with another inhabiting the High Tatra Mountains. Much less is known about populations inhabiting the Alps, where EuPC populations are extremely rare. Recently, four new melanic populations have been discovered in lakes in the Western Italian Alps, offering the opportunity to study their origin and adaptations. We inferred phylogenetic relationships of melanic high‐mountain populations in order to disentangle their history and clarify the colonization patterns of alpine populations. Molecular data suggest that dark populations originated from at least two ancestors, one genetically close to boreal haplotypes, the other apparently related to refugial populations that survived in southern Europe. Therefore, dark pigmentation and obligate parthenogenesis evolved independently within both lineages inhabiting the studied lakes as extreme local adaptations to the alpine environment. Finally, since impacts of human‐related activities and climate changes on mountain species are known to be dramatic, we pose strong issues for the conservation of these extremely localized endemisms. © 2014 The Linnean Society of London     

Behavioral changes induced by the thyrotropin-releasing hormone analogue, RGH 2202

The behavioral activity of the thyrotropin-releasing hormone (TRH) analogue, L-6-ketopiperidine-2-carbonyl-leucyl-L-prolinamide (RGH 2202), has been studied in the rat. The number of errors in a radial maze test was reduced after acute intraperitoneal (IP) injection of RGH 2202 at the dose of 5 or 10 mg/kg. Grooming activity was increased with a lower dose, 1 mg/kg. Hypoxia-induced amnesia, as assessed with active and passive avoidance behavior tests, was reversed in rats treated with 5 or 10 mg/kg of the drug. The loss of learning and memory capacity shown by aged rats in the same behavioral tests was also reduced after injection of RGH 2202. In a test for sexual activity of male rats, the higher dose of the drug induced a facilitation of mounting and ejaculations, while smaller doses were ineffective. The rotorod test revealed a decreased number of falls in animals treated with 5 or 10 mg/kg of RGH 2202. In all behavioral tests, the same doses of natural thyrotropin-releasing hormone (TRH) were less effective, indicating that this analogue may be qualified as a potentially active drug in human pathologies.     

Cloning and disruption of the gene encoding an extracellular metalloprotease of Aspergillus fumigatus

Aspergillus fumigatus secretes a serine alkaline protease (ALP) and a metalloprotease (MEP) when the fungus is cultivated in the presence of collagen as sole nitrogen and carbon source. The gene encoding ALP was isolated and characterized previously. We report here the cloning and the sequencing of the gene encoding MEP. Genomic and cDNA clones were isolated from A. fumigatus libraries using synthetic oligonucleotides as probes. Stretches of the deduced amino acid sequence were found to be in agreement with the N-terminal amino acid sequence of MEP and with internal peptide sequences. The amino acid sequence of the enzyme contains a putative active-site sequence HEYTH homologous to the active site of other bacterial and eukaryotic zinc metalloproteases. Sequence analysis reveals that MEP has a pre-proregion consisting of 245 amino acid residues preceding the 388 amino acid residues of the mature region (molecular mass of 42 kDa). An alp mep mutant, deficient in proteolytic activity at neutral pH in vitro, was constructed and tested for pathogenicity in a murine model. No difference in pathogenicity was observed between the wild-type strain and the alp mep double mutant, suggesting that ALP and MEP are not essential for the invasion of the lung tissues by A. fumigatus.