Genetic characterization of an almond germplasm collection and volatilome profiling of raw and roasted kernels.

Almond is appreciated for its nutraceutical value and for the aromatic profile of the kernels. In this work, an almond collection composed of 96 Sicilian accessions complemented with 10 widely cultivated cultivars was phenotyped for the production of volatile organic compounds using a proton-transfer time-of-flight mass spectrometer and genotyped using the Illumina Infinium®18 K Peach SNP array. The profiling of the aroma was carried out on fresh and roasted kernels enabling the detection of 150 mass peaks. Sixty eight, for the most related with sulfur compounds, furan containing compounds, and aldehydes formed by Strecker degradation, significantly increased during roasting, while the concentration of fifty-four mass peaks, for the most belonging to alcohols and terpenes, significantly decreased. Four hundred and seventy-one robust SNPs were selected and employed for population genetic studies. Structure analysis detected three subpopulations with the Sicilian accessions characterized by a different genetic stratification compared to those collected in Apulia (South Italy) and the International cultivars. The linkage-disequilibrium (LD) decay across the genome was equal to r2 = 0.083. Furthermore, a high level of collinearity (r2 = 0.96) between almond and peach was registered confirming the high synteny between the two genomes. A preliminary application of a genome-wide association analysis allowed the detection of significant marker-trait associations for 31 fresh and 33 roasted almond mass peaks respectively. An accurate genetic and phenotypic characterization of novel germplasm can represent a valuable tool for the set-up of marker-assisted selection of novel cultivars with an enhanced aromatic profile.

Glassy Magnetic Behavior and Correlation Length in Nanogranular Fe-Oxide and Au/Fe-Oxide Samples.

In nanoscale magnetic systems, the possible coexistence of structural disorder and competing magnetic interactions may determine the appearance of a glassy magnetic behavior, implying the onset of a low-temperature disordered collective state of frozen magnetic moments. This phenomenology is the object of an intense research activity, stimulated by a fundamental scientific interest and by the need to clarify how disordered magnetism effects may affect the performance of magnetic devices (e.g., sensors and data storage media). We report the results of a magnetic study that aims to broaden the basic knowledge of glassy magnetic systems and concerns the comparison between two samples, prepared by a polyol method. The first can be described as a nanogranular spinel Fe-oxide phase composed of ultrafine nanocrystallites (size of the order of 1 nm); in the second, the Fe-oxide phase incorporated non-magnetic Au nanoparticles (10-20 nm in size). In both samples, the Fe-oxide phase exhibits a glassy magnetic behavior and the nanocrystallite moments undergo a very similar freezing process. However, in the frozen regime, the Au/Fe-oxide composite sample is magnetically softer. This effect is explained by considering that the Au nanoparticles constitute physical constraints that limit the length of magnetic correlation between the frozen Fe-oxide moments.

Mechanism of magnetic heating in Mn-doped magnetite nanoparticles and the role of intertwined structural and magnetic properties.

We study the mechanism of heat generation, induced by an alternating magnetic field, in magnetite nanoparticles doped with manganese, produced by thermal decomposition from organometallic precursors. We investigate a set of four samples obtained by varying the duration of the reflux treatment carried out at a temperature of 300 °C during the synthetic procedure. On increasing this parameter from 60 to 180 minutes, the mean size of the nanoparticles increases, though remaining below 10 nm, as well as the saturation magnetization, which in all the samples, thanks to the Mn doping, is higher than that in magnetite nanoparticles taken as a reference. The combination of these two events has two main consequences. First, it determines the intensity of dipolar interactions between the nanoparticles, thus influencing their magnetic relaxing behavior, which, in turn, is closely related to the heating efficiency. Secondly, in a heating test, it is possible to operate in the regime of non-linear magnetic response of the nanoparticles at values of amplitude and frequency of the alternating field usually employed for biomedical applications. We show that, in this regime, the Specific Absorption Rate (SAR) in each sample depends linearly on the fraction of nanoparticles that are not superparamagnetic. This opens the possibility of modulating the heating capacity of the produced nanoparticles, so as to match specific needs, changing only a single synthesis parameter and opportunely exploiting the strict connection between structural features, magnetic properties and measurement conditions.

Influence of Mn co-doping on the magnetic properties of planar arrays of GaxFe4-xN nanocrystals in a GaN matrix.

Magnetic nanocrystals embedded in a semiconducting matrix are gaining increasing attention for potential applications in spintronic devices. We report about the magnetic behavior of Fe and Mn doped GaN samples, fabricated by means of metal organic vapor phase epitaxy, featuring a planar array of γ'-GaxFe4-xN nanocrystals embedded in the GaN matrix. We consider a set of three samples grown with the same nominal Fe content and different Mn concentration, including one with no Mn. In the sample with the highest Mn content, we detect Mn in the γ'-GaxFe4-xN lattice and also the presence of ε-Fe3N nanocrystals. The samples exhibit a paramagnetic signal, ascribed to the GaN matrix, and a ferromagnetic one given by the nanocrystals: the former increases on increasing the Mn co-doping whereas the latter decreases. In the three samples, magnetically relaxing nanocrystals coexist with non-relaxing ones and dipolar magnetic interactions strongly affect the magnetothermal behavior. The analysis of these complex magnetic phenomena is correlated to the structural and compositional properties of the nanocrystals and to their arrangement into the GaN matrix, opening new perspectives for tuning on demand the magnetic response of this relevant system.

Interplay between magnetic anisotropies in CoAu and Co films and antidot arrays: effects on the spin configuration and hysteretic behavior.

We studied (i) a set of three Co : Au continuous films, grown by sputtering co-deposition (∼80 nm thick) with concentration ratios of 2 : 1, 1 : 1 and 1 : 0 (i.e., a pure Co film was also included), and (ii) a corresponding set of antidot arrays, produced by nanosphere lithography with the same hexagonal pattern (nominal lattice periodicity ∼520 nm). The samples were investigated by atomic and magnetic force microscopy and SQUID magnetometry. A twofold aim was fulfilled: to gain information on the magnetism of the CoAu compound (saturation magnetization, effective in-plane and out-of-plane anisotropy, exchange stiffness constant and magnetostrictive behavior) and to compare the magnetic behavior of the continuous and patterned samples. The continuous films exhibited a variety of hysteretic behaviours and magnetic configurations, ruled by the interplay between different magnetic anisotropy terms (magnetocrystalline, magnetoelastic and shape). The Co1Au1 film was anisotropic in the plane, whereas Co2Au1 and Co were isotropic and had an out-of-plane magnetization component; stripe domains were observed in Co2Au1, resulting in a transcritical hysteresis loop. A key role in determining these properties was ascribed to the magnetoelastic anisotropy term. Unlike the continuous films, the antidot arrays showed a similar hysteretic behavior and important similarities in the spin configuration were pointed out, despite the different compositions. We argue, also based on micromagnetic simulations, that this occurred because the nanopatterning enabled a local modification of the shape anisotropy, thus smoothing out the differences observed in the continuous films.

HaploSNP affinities and linkage map positions illuminate subgenome composition in the octoploid, cultivated strawberry (Fragaria×ananassa).

The cultivated strawberry, Fragaria×ananassa possesses a genetically complex allo-octoploid genome. Advances in genomics research in Fragaria, including the release of a genome sequence for F. vesca, have permitted the development of a high throughput whole genome genotyping array for strawberry, which promises to facilitate genetics and genomics research. In this investigation, we used the Axiom® IStraw90®)array for linkage map development, and produced a linkage map containing 8,407 SNP markers spanning 1,820cM. Whilst the linkage map provides good coverage of the genome of both parental genotypes, the map of 'Monterey' contained significantly fewer mapped markers than did that of 'Darselect'. The array contains a novel marker class known as haploSNPs, which exploit homoeologous sequence variants as probe destabilization sites to effectively reduce marker ploidy. We examined these sites as potential indicators of subgenomic identities by using comparisons to allele states in two ancestral diploids. On this basis, haploSNP loci could be inferred to be derived from F. vesca, F. iinumae, or from an unknown source. When the identity classifications of haploSNPs were considered in conjunction with their respective linkage map positions, it was possible to define two discrete subgenomes, while the remaining homoeologues of each chromosome could not be partitioned into two discrete subgenomic groupings. These findings suggested a novel hypothesis regarding octoploid strawberry subgenome structure and evolutionary origins.

Diurnal variations in brain iron concentrations in BXD RI mice.

Under normal and dietary iron deficiency conditions, the BXD recombinant inbred (RI) strains of mice show large variations in regional brain iron concentration, particularly in the ventral midbrain (VMB). In a study utilizing just one of the BXD strains, diurnal changes in subregional brain iron concentration were found, which were dependent on the brain region and sex of the mice. The focus of this study was to determine if diurnal changes in VMB can be found across other BXD RI strains and whether a diurnal effect would be common to all strains or variable across strains similar to the large strain variability in iron concentrations determined during the first part of the light phase. Eight RI (BXD type) strains of mice of both sexes were selected for this study. Mice were sacrificed at postnatal day 120: half in the light phase (LP) and half in the dark phase (DP) of the light-dark cycle. Iron concentrations were determined in VMB, which was the primary region of interest, and five other brain regions. Exploratory analysis was also done on liver and spleen iron concentrations to assess for diurnal changes. Three strains showed clear diurnal variation in iron in the VMB and the others strains showed diurnal variations in other regions. These changes were not equally apparent in both sexes. Exploratory analysis also found strain×sex-dependent diurnal differences in spleen and liver iron. In conclusion, significant brain-regional-specific diurnal changes in total iron concentrations were found in a selection of BXD RI mice. Sex and strain are functional determinates of which regions will be affected and in what direction the affect will be. The study provides an animal model for future work into determining the biological and genetic basis of circadian influences on VMB iron homeostasis.

First Report of Phytoplasmas Groups 16SrI and 16SrXV in Crotalaria juncea in Brazil.

Sunn hemp (Crotalaria juncea L., Fabaceae) is widely used as a cover crop in sugar cane and citrus plantations in Brazil. C. juncea has been reported in São Paulo State (SPS) by Wulff et al. (3) as a host of the phytoplasma associated with symptoms of huanglongbing (HLB) in citrus, a member of group 16SrIX, that induces witches'-broom in sunn hemp (3). In studying the distribution of group 16SrIX phytoplasma in C. juncea in SPS, we identified this species as a new host of two phytoplasmas. Sunn hemp fields were inspected for symptoms usually associated with phytoplasma infections, such as leaf yellowing, shoot proliferation, witches'-brooms, and virescence. Ninety-nine plant samples were collected and DNA was extracted with the CTAB protocol from stems. Nested PCR was carried out with primers P1/P7, followed by amplification with primers fU3/rU5 (2), both sets being universal for phytoplasma. Asymptomatic sunn hemp samples were used as negative controls and were negative in PCR reactions. PCR products were directly sequenced with primers P1/P7 and fU3/rU5 and phytoplasma identification was conducted with BLASTn and in silico RFLP analysis for delineation of subgroups (4). Plants showing leaf yellowing (three plants; Catanduva County), shoot proliferation (one plant; Ibirá County), or witches'-brooms (one plant; Promissão County) symptoms were found to be infected with the 16SrI phytoplasma group, subgroup S. The 16S rDNA sequence (GenBank Accession No. KF878383) showed 99% identity (E value 0.0) with Candidatus Phytoplasma asteris, Onion yellows phytoplasma OY-M (AP006628), Mulberry yellow dwarf phytoplasma (GQ249410), and Ash witches'-broom phytoplasma (AY566302), among other phytoplasmas from the same group. Sunn hemp plants with shoot proliferation (three plants) carried the 16SrXV phytoplasma group, subgroup A, found in Ibirá (two plants) and Catanduva (one plant) counties, SPS. This sequence (GenBank Accession No. KF878382) displayed 99% identity (E value 0.0) with Ca. P. brasiliense, Hibiscus witches'-broom phytoplasma (AF147708), Guazuma ulmifolia witches'-broom phytoplasma (HQ258882, HQ258883), and Cauliflower stunt phytoplasma (JN818845). Both phytoplasma groups described in this report, 16SrI and 16SrXV, were collected in May 2010 and both have limited geographic distribution and occurred at low incidence. Phytoplasma of group 16SrI (Ca. P. asteris) was identified in C. spectabilis in India (1). To our knowledge, this is the first report of phytoplasmas groups 16SrI and 16SrXV in sunn hemp. References: (1) S. Kumar et al. Plant Dis. 94:1265, 2010. (2) E. Seemüller et al. Int. J. Syst. Bacteriol. 44:440, 1994. (3) N. A. Wulff et al. Tropical Plant Pathol. 34:S7, 2009. (4) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.

Detection of the dynamic magnetic behavior of the antiferromagnet in exchange-coupled NiFe/IrMn bilayers.

The magnetothermal behavior of antiferromagnetic IrMn layers of different thickness (3, 6, 10 nm) has been studied by exploiting the exchange coupling with a ferromagnetic 5 nm-thick NiFe layer. A procedure has been devised for the measurement of the magnetization of the NiFe/IrMn bilayers as a function of temperature and time at different values of an external magnetic field, Hinv, antiparallel to the unidirectional exchange anisotropy. This analysis allows one to probe the effective distribution of anisotropy energy barriers of the antiferromagnetic phase, as sensed by the ferromagnetic layer. Two magnetic regimes have been distinguished. At temperature T < 100 K, the interfacial IrMn spins are frozen in a glassy state and are collectively involved in the exchange coupling with the NiFe spins. At T âˆ¼ 100 K the collective state breaks up; thus, above this temperature, only the interfacial IrMn spins which are tightly polarized by the IrMn nanograins, forming the bulk of the layer, are effectively involved in the exchange coupling mechanism. Due to that, for T > 100 K the exchange coupling is ruled by the anisotropy energy barriers of the bulk IrMn nanograins, namely by the layer thickness. The thermal evolution of the exchange field and of the coercivity in the three samples is coherently explained in the framework of this description of the dynamic magnetic behavior of the IrMn phase.

Interaction between catechol-O-methyltransferase (COMT) Val158Met genotype and genetic vulnerability to schizophrenia during explicit processing of aversive facial stimuli.

BACKGROUND: Emotion dysregulation is a key feature of schizophrenia, a brain disorder strongly associated with genetic risk and aberrant dopamine signalling. Dopamine is inactivated by catechol-O-methyltransferase (COMT), whose gene contains a functional polymorphism (COMT Val158Met) associated with differential activity of the enzyme and with brain physiology of emotion processing. The aim of the present study was to investigate whether genetic risk for schizophrenia and COMT Val158Met genotype interact on brain activity during implicit and explicit emotion processing. METHOD: A total of 25 patients with schizophrenia, 23 healthy siblings of patients and 24 comparison subjects genotyped for COMT Val158Met underwent functional magnetic resonance imaging during implicit and explicit processing of facial stimuli with negative emotional valence. RESULTS: We found a main effect of diagnosis in the right amygdala, with decreased activity in patients and siblings compared with control subjects. Furthermore, a genotype × diagnosis interaction was found in the left middle frontal gyrus, such that the effect of genetic risk for schizophrenia was evident in the context of the Val/Val genotype only, i.e. the phenotype of reduced activity was present especially in Val/Val patients and siblings. Finally, a complete inversion of the COMT effect between patients and healthy subjects was found in the left striatum during explicit processing. CONCLUSIONS: Overall, these results suggest complex interactions between genetically determined dopamine signalling and risk for schizophrenia on brain activity in the prefrontal cortex during emotion processing. On the other hand, the effects in the striatum may represent state-related epiphenomena of the disorder itself.

Evidence that hippocampal-parahippocampal dysfunction is related to genetic risk for schizophrenia.

BACKGROUND: Abnormalities in hippocampal-parahippocampal (H-PH) function are prominent features of schizophrenia and have been associated with deficits in episodic memory. However, it remains unclear whether these abnormalities represent a phenotype related to genetic risk for schizophrenia or whether they are related to disease state. METHOD: We investigated H-PH-mediated behavior and physiology, using blood oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI), during episodic memory in a sample of patients with schizophrenia, clinically unaffected siblings and healthy subjects. RESULTS: Patients with schizophrenia and unaffected siblings displayed abnormalities in episodic memory performance. During an fMRI memory encoding task, both patients and siblings demonstrated a similar pattern of reduced H-PH engagement compared with healthy subjects. CONCLUSIONS: Our findings suggest that the pathophysiological mechanism underlying the inability of patients with schizophrenia to properly engage the H-PH during episodic memory is related to genetic risk for the disorder. Therefore, H-PH dysfunction can be assumed as a schizophrenia susceptibility-related phenotype.

Study of the magnetic microstructure of Ni/NiO nanogranular samples above the electric percolation threshold by magnetoresistance measurements.

Magnetoresistance measurements have been exploited to gain information on the magnetic microstructure of two Ni/NiO nanogranular materials consisting of Ni nanocrystallites (mean size of the order of 10 nm) embedded in a NiO matrix and differing in the amount of metallic Ni, ~33 and ~61 vol%. The overall conductance of both samples is metallic in character, indicating that the Ni content is above the percolation threshold for electric conductivity; the electric resistivity is two orders of magnitude smaller in the sample with higher Ni fraction (10(-5) Ωm against 10(-3) Ωm). An isotropic, spin-dependent magnetoresistance has been measured in the sample with lower Ni content, whereas both isotropic and anisotropic magnetoresistance phenomena coexist in the other material. This study, associated with magnetization loop measurements and the comparison with the exchange bias effect, allows one to conclude that in the sample with lower Ni content neither the physical percolation of the Ni nanocrystallites nor the magnetic percolation (i.e., formation of a homogeneous ferromagnetic network) are achieved; in the other sample physical percolation is reached while magnetic percolation is still absent. In both behaviors, a key role is played by the NiO matrix, which brings about a magnetic nanocrystallite/matrix interface exchange energy term and rules both the direct exchange interaction among Ni nanocrystallites and the magnetotransport properties of these nanogranular materials.

Physical exercise in young patients with congenital heart disease.

The aim of this paper is to clarify two important aspects about patients affected by congenital heart disease. Their functional status plays a dominant role in the definition of quality of life related to health status, because of its implication in working and recreational activities. In the first part, we explain their cardiovascular adaptation on exercise, based on pathology (Tetralogy of Fallot, transposition of great arteries, univentricular heart). In the second part, we explain the risk of sudden death from congenital heart disease due to exercise, because of electrical cardiac instability and/or the structural abnormalities of the cardiovascular parietal walls.

Catechol-O-methyltransferase Val(158)Met association with parahippocampal physiology during memory encoding in schizophrenia.

BACKGROUND: Catechol-O-methyltransferase (COMT) Val158Met has been associated with activity of the mesial temporal lobe during episodic memory and it may weakly increase risk for schizophrenia. However, how this variant affects parahippocampal and hippocampal physiology when dopamine transmission is perturbed is unclear. The aim of the present study was to compare the effects of the COMT Val158Met genotype on parahippocampal and hippocampal physiology during encoding of recognition memory in patients with schizophrenia and in healthy subjects. METHOD: Using blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI), we studied 28 patients with schizophrenia and 33 healthy subjects matched for a series of sociodemographic and genetic variables while they performed a recognition memory task. RESULTS: We found that healthy subjects had greater parahippocampal and hippocampal activity during memory encoding compared to patients with schizophrenia. We also found different activity of the parahippocampal region between healthy subjects and patients with schizophrenia as a function of the COMT genotype, in that the predicted COMT Met allele dose effect had an opposite direction in controls and patients. CONCLUSIONS: Our results demonstrate a COMT Val158Met genotype by diagnosis interaction in parahippocampal activity during memory encoding and may suggest that modulation of dopamine signaling interacts with other disease-related processes in determining the phenotype of parahippocampal physiology in schizophrenia.

Epilepsy surgery of posterior quadrant dysplasia in the first year of life: experience of a single centre with long term follow-up.

Posterior quadrant dysplasia (PQD) is a rare variant of cortical dysplasia involving the posterior regions of a single hemisphere. It is always associated with early onset, refractory epilepsy often characterized by a "catastrophic" evolution. The experience on its surgical management during the first year of life is limited to sporadic, isolated cases. Between 2002 and 2005, four children less than one-year-old and affected by drug-resistant epilepsy associated with PQD were admitted to our Institution and underwent surgical treatment. One patient remained seizure-free during all the follow-up (Engel I). The remaining three children showed a recurrence of the seizures, requiring subsequent surgical procedures in two cases. In one case (Engel II), the seizure control has been obtained thanks to pharmacological treatment. The other two patients respectively had only a partial (Engel III) and a less relevant reduction of the number of seizures (Engel IV). Both the epileptic and the neuropsychological outcome of our series were significantly influenced by persistent contralateral interictal anomalies rather than by the timing of the surgical procedure. Unpredictable results should be expected in this kind of patients if there is the detection of contralateral independent epileptiform activities on the EEG at diagnosis. Parents and relatives should be aware of the results' variability, even though a reduction of seizures may be expected, enabling an easier handling of the child's condition.

Changing the magnetism of amorphous FeSiB by mechanical milling.

We have studied the magnetic properties of a sample obtained by high-energy mechanical milling from a ferromagnetic FeSiB amorphous ribbon. The milled material mainly consists of a Fe-based amorphous matrix embedding a minor fraction of α-Fe nanocrystallites (∼23%), and magnetization dynamics effects characterize the magnetic behavior. In particular, a magnetic transition occurs at T ∼ 50 K, from a low temperature disordered collective frozen state, similar to a spin-cluster-glass, to a high temperature regime where ferromagnetism predominates. The phenomenon has been ultimately ascribed to the local modification of the interatomic distance distribution in the amorphous matrix, induced by milling.

[Survey on sports practice and physical activity of primary school children living in the area of Bologna Local Health Unit in relation with some individual and environmental variables]. / Indagine sulla pratica sportiva e le abitudini motorie dei bambini della scuola primaria del territorio dell'Azienda USL di bologna in relazione ad alcune variabili individuali e ambientali.

A randomized stratified sample of 522 children attending the third class of primary schools within the area of Bologna Local Health Unit was analysed for physical activity and sports practice. Information about the children's habits and availability of facilities for physical and sports activities were collected by means of structured questionnaires completed by children (507 respondents), parents (491), reference teachers for physical education (26) and class teachers (46) during the school year 2006-07. At the same time, the children's heights and weights were measured in order to calculate BMI values. Regular sports activity is practised by 80.1% of children (males: 82.4%, females: 77.6%), with significant diferences between genders only in children with at least one non-Italian parent (M>F, p < 0.05); the practice of sports is influenced by the area of residence (metropolitan > plain and hills, p < 0.05) and nationality (Italians > non-Italians, p < 0.01). Children with at least one actively sports practising parent are involved more frequently in sports activities (p < 0.001). In free time, sedentary activities are prevalent for both sports-practising children and not. However children not involved in regular sports activities tend to practise outdoor physical activities with a frequency significantly higher than children involved in sports (17.3% vs 10.4% of respondents). The percentage of completely sedentary children, who stated that they practise neither sports nor physical activity in their free time, is 7.3% (metropolitan area: 4.5%, hills: 8.7%, plain: 10.6%). The prevalence of overweight is 24.4%, of obesity 9.7%, with a better distribution of BMI values in the metropolitan area where there is the highest occurrence of positive conditions and behaviours: availability of sports facilities, the highest prevalence of sports practice, and the lowest prevalence of completely sedentary children.

[Prospective observational study of pneumonia in an Italian hospital]. / Studio osservazionale prospettico delle polmoniti in un ospedale italiano.

A prospective observational study was conducted during a two-year period to evaluate the prevalence of hospitalized pneumonia in six hospital units of the Bologna S.Orsola-Malpighi hospital (Italy). The selected units were: general surgery, general medicine, internal medicine, geriatrics, respiratory physiopathology and pneumology, with a total of 205 beds and around 4,800 admissions per year. Data were collected from the clinical cards and cases of pneumonia were distinguished by origin (community-acquired or hospital-acquired according to CDC definition), individual and clinical characteristics, and aetiology. The study involved 486 cases of pneumonia: 75 hospital-acquired and 411 community-acquired (84.6%). Patients affected by hospital-acquired pneumonia were older (average age 77 years) compared to community-acquired cases (74 years) and show a more homogeneous gender distribution (males: 48.0% vs 59.4%). Hospital stays (42 vs 21 days) and mortality rates (24.0% vs 11.7%) were significantly higher in hospital-acquired pneumonia. The incidence rate of nosocomial pneumonia was 7.4 per 1000 hospitalized patients and increased to 17-23 per 1000 in the pneumology and respiratory physiopathology units. Only 16.9% of cases had an aetiological diagnosis (14.1% community-acquired; 31.8% hospital-acquired); the most common isolates were S. aureus and P. aeruginosa. The hospital-acquired cases were caused by Gram-negative bacilli more often than the community-acquired cases, and infections were more frequently polymicrobial (37.5% vs 3.4%). In order to reduce morbidity and mortality due to pneumonia it is important to implement prevention measures in the community (i.e. specific vaccination campaigns), improve clinical protocols for aetiological diagnosis in hospitalised patients and increase epidemiological surveillance of hospital-acquired infections.

Reduced brain-derived neurotrophic factor is associated with a loss of serotonergic innervation in the hippocampus of aging mice.

Brain-derived neurotrophic factor (BDNF) regulates monoamine neuronal growth, survival and function in development and throughout adulthood. At 18 months of age, mice with constitutive reductions in BDNF expression show decreased serotonin innervation in the hippocampus compared with age-matched wildtype mice. It is not known, however, whether age-accelerated loss of serotonergic innervation in BDNF(+/-) mice occurs in other brain regions, advances beyond 18 months or is associated with alterations in other neurotransmitter systems. In this study, immunocytochemistry was used to assess serotonergic and catecholaminergic innervation in 26-month-old BDNF(+/-) mice. Age-related loss of serotonin axons in the hippocampus was potentiated in BDNF(+/-) mice compared with wildtype mice at this late age, particularly in the CA1 subregion. By contrast, aging BDNF(+/-) mice showed increased serotonin innervation of the basomedial nucleus of the amygdala. In the noradrenergic system, BDNF(+/-) mice showed reduced numbers of cell bodies and fibers in the locus coeruleus compared with age-matched wildtype mice, whereas no changes were observed in dopaminergic innervation with respect to genotype. In vivo zero net flux microdialysis in awake mice showed a significant decrease in extracellular serotonin levels in the hippocampus in BDNF(+/-) mice at 20 months of age. Thus, reduced BDNF is associated with altered serotonergic and noradrenergic innervation in aging mice and, in particular, with accelerated loss of serotonergic innervation to the hippocampus that is manifest as a decrease in basal neurotransmission.