Differences in intrinsic properties of dorsally and ventrally located lateral amygdala neurons of the rat

During Pavlovian auditory fear conditioning a previously neutral auditory stimulus (CS) gains emotional significance through pairing with a noxious unconditioned stimulus (US). These associations are believed to be formed by way of plasticity at auditory input synapses on principal neurons of the lateral nucleus of the amygdala (LA). While the LA has been implicated as a key brain structure for fear learning, how its network of cellular components performs these operations is not yet known...

Acute restraint stress alters subsequent auditory fear conditioning in the rat

The neural basis of Pavlovian fear conditioning is well understood and depends upon neural processes within the amygdala. Stress is known to play a role in the modulation of fear-related behavior, including Pavlovian fear conditioning. Chronic restraint stress has been shown to enhance fear conditioning to discrete and contextual stimuli; however, the time course and extent of restraint that is essential for this modulation of fear learning remains unclear. Thus, we tested the extent to which a single exposure to 1 hr of restraint would alter subsequent auditory fear conditioning in rats.

Quantification of the total neuronal structure of the fear conditioning circuit of the lateral amygdala of the rat

During Pavlovian auditory fear conditioning a previously neutral auditory stimulus (CS) gains emotional significance through pairing with a noxious unconditioned stimulus (US). These associations are believed to be formed by way of plasticity at auditory input synapses on principal neurons in the lateral nucleus of the amygdala (LA). In order to begin to understand how fear memories are stored and processed by synaptic changes in the LA, we have quantified both the entire neural number and the sub-cellular structure of LA principal neurons.We first used stereological cell counting methods on Gimsa or GABA immunostained rat brain. We identified 60,322+/-1408 neurons in the LA unilaterally (n=7). Of these 16,917+/-471 were GABA positive. The intercalated nuclei were excluded from the counts and thus GABA cells are believed to represent GABAergic interneurons. The sub-nuclei of the LA were also independently counted. We then quantified the morphometric properties of in vitro electrophysiologically identified principal neurons of the LA, corrected for shrinkage in xyz planes. The total dendritic length was 9.97+/-2.57mm, with 21+/-4 nodes (n=6). Dendritic spine density was 0.19+/-0.03 spines/um (n=6). Intra-LA axon collaterals had a bouton density of 0.1+/-0.02 boutons/um (n=5). These data begin to reveal the finite cellular and sub-cellular processing capacity of the lateral amygdala, and should facilitate efforts to understand mechanisms of plasticity in LA.

Different correlation of Sphingosine-1-Phosphate receptor 1 with receptor activator of nuclear factor kappa B ligand and regulatory T cells in rat periapical lesions

Introduction Sphingosine-1-phosphate receptor 1 (S1P1) is crucial for regulation of immunity and bone metabolism. This study aimed to investigate the expression of S1P1 in rat periapical lesions and its relationship with receptor activator of nuclear factor kappa B ligand (RANKL) and regulatory T (Treg) cells. Methods Periapical lesions were induced by pulp exposure in the first lower molars of 55 Wistar rats. Thirty rats were killed on days 0, 7, 14, 21, 28, and 35, and their mandibles were harvested for x-ray imaging, micro–computed tomography scanning, histologic observation, immunohistochemistry, enzyme histochemistry, and double immunofluorescence analysis. The remaining 25 rats were killed on days 0, 14, 21, 28, and 35, and mandibles were harvested for flow cytometry. Results The volume and area of the periapical lesions increased from day 0 to day 21 and then remained comparably stable after day 28. S1P1-positive cells were observed in the inflammatory periapical regions; the number of S1P1-positive cells peaked at day 14 and then decreased from day 21 to day 35. The distribution of S1P1-positive cells was positively correlated with the dynamics of RANKL-positive cells but was negatively correlated with that of Treg cells. Conclusions S1P1 expression was differentially correlated with RANKL and Treg cell infiltration in the periapical lesions and is therefore a contributing factor to the pathogenesis of such lesions.

The characterisation of Ureaplasma species isolated from the Chorioamnion of women who deliver late Preterm

This thesis investigated, for the first time, the prevalence of Ureaplasma species infection within the placentae of women who delivered in the late preterm stages of pregnancy. The presence of these microorganisms was associated with either severe inflammation within the placenta or, for some women, there were no pregnancy complications and these women delivered at term. Ureaplasmas are able to vary their surface exposed lipoproteins and we demonstrated that different host immune responses were generated in vivo to different sized surface lipoproteins. This may explain why ureaplasma infections do not always result in adverse pregnancy and neonatal outcomes.

The transition from isolated, rural contexts to boarding school: Can school physical education play a part?

This study considers the transition of children from rurally isolated schooling environments to boarding school contexts. There is an assumption that these transitions are often carried out with little fuss. Moreover; there is some evidence to show this transition is beneficial to both child and school. However, contrary data suggest that parents of such children are deeply concerned about this transition from a sport and physical education perspective (Wright et al., 1998). This study attempts to address this under-researched area. Data were gathered using semi-structured interviews with teachers, children and parents in an isolated schooling context, and with teachers and children from a boarding school in a regional Queensland centre. Some videotape data of children in physical education and sporting contexts were also collected. The data indicate that the transition from rural contexts to highly competitive boarding school environments is relatively smooth, with physical education and sport being significant contributors to this process.

Comparative analysis of genome maintenance genes in naked mole rat, mouse, and human

Genome maintenance (GM) is an essential defense system against aging and cancer, as both are characterized by increased genome instability. Here, we compared the copy number variation and mutation rate of 518 GM-associated genes in the naked mole rat (NMR), mouse, and human genomes. GM genes appeared to be strongly conserved, with copy number variation in only four genes. Interestingly, we found NMR to have a higher copy number of CEBPG, a regulator of DNA repair, and TINF2, a protector of telomere integrity. NMR, as well as human, was also found to have a lower rate of germline nucleotide substitution than the mouse. Together, the data suggest that the long-lived NMR, as well as human, has more robust GM than mouse and identifies new targets for the analysis of the exceptional longevity of the NMR.

Genome sequence of marine bacterium idiomarina sp. strain 28-8, isolated from Korean ark shells

Idiomarina sp. strain 28-8 is an aerobic, Gram-negative, flagellar bacterium isolated from the bodies of ark shells (Scapharca broughtonii) collected from underwater sediments in Gangjin Bay, South Korea. Here, we present the draft genome sequence of Idiomarina sp. 28-8 (2,971,606 bp, with a G+C content of 46.9%), containing 2,795 putative coding sequences.

The transcriptome of the bowhead whale Balaena mysticetus reveals adaptations of the longest‐lived mammal

Mammals vary dramatically in lifespan, by at least two-orders of magnitude, but the molecular basis for this difference remains largely unknown. The bowhead whale Balaena mysticetus is the longest-lived mammal known, with an estimated maximal lifespan in excess of two hundred years. It is also one of the two largest animals and the most cold-adapted baleen whale species. Here, we report the first genome-wide gene expression analyses of the bowhead whale, based on the de novo assembly of its transcriptome. Bowhead whale or cetacean-specific changes in gene expression were identified in the liver, kidney and heart, and complemented with analyses of positively selected genes. Changes associated with altered insulin signaling and other gene expression patterns could help explain the remarkable longevity of bowhead whales as well as their adaptation to a lipid-rich diet. The data also reveal parallels in candidate longevity adaptations of the bowhead whale, naked mole rat and Brandt's bat. The bowhead whale transcriptome is a valuable resource for the study of this remarkable animal, including the evolution of longevity and its important correlates such as resistance to cancer and other diseases.

The effects of osteoporosis on osseointegration in the rat maxilla

The study investigated the effects of oestrogen deficiency on dental implant in a rat model. An osteoporosis rat model was successfully established for dental implant research and it was noted that bone cells functioned differently in osteoporotic condition during the healing of dental implant. The study further demonstrated that implant surface roughness could stimulate bone formation, therefore, improve the bone healing in osteoporotic condition.

Spectrum of ankylosing spondylitis in Portugal. Development of BASDAI, BASFI, BASMI and mSASSS reference centile charts

The availability of population-specific normative data regarding disease severity measures is essential for patient assessment. The goals of the current study were to characterize the pattern of ankylosing spondylitis (AS) in Portuguese patients and to develop reference centile charts for BASDAI, BASFI, BASMI and mSASSS, the most widely used assessment tools in AS. AS cases were recruited from hospital outpatient clinics, with AS defined according to the modified New York criteria. Demographic and clinical data were recorded. All radiographs were evaluated by two independent experienced readers. Centile charts for BASDAI, BASFI, BASMI and mSASSS were constructed for both genders, using generalized linear models and regression models with duration of disease as independent variable. A total of 369 patients (62.3% male, mean ± (SD) age 45.4 ± 13.2 years, mean ± (SD) disease duration 11.4 ± 10.5 years, 70.7% B27-positive) were included. Family history of AS in a first-degree relative was reported in 17.6% of the cases. Regarding clinical disease pattern, at the time of assessment 42.3% had axial disease, 2.4% peripheral disease, 40.9% mixed disease and 7.1% isolated enthesopatic disease. Anterior uveitis (33.6%) was the most common extra-articular manifestation. The centile charts suggest that females reported greater disease activity and more functional impairment than males but had lower BASMI and mSASSS scores. Data collected through this study provided a demographic and clinical profile of patients with AS in Portugal. The development of centile charts constitutes a useful tool to assess the change of disease pattern over time and in response to therapeutic interventions.

Characterisation of lignins isolated from sugarcane bagasse pretreated with acidified ethylene glycol and ionic liquids

Sugarcane bagasse pretreatment processes using acidified aqueous ethylene glycol (EG) and ionic liquids (ILs) have been reported recently. In this study, recovery of lignins from these processes was conducted, as well as determination of their physico-chemical properties. The amount of lignins recovered from 1-butyl-3-methylimidazolium chloride ([bmim]Cl) with HCl as a catalyst and [bmim][CH3SO3] was ∼42%, and ∼35%–36% by EG with HCl or H2SO4 as a catalyst, respectively. The isolated lignins were characterised using wet chemistry, spectroscopy and thermogravimetry analysis (TGA), and the results compared to soda lignin from NaOH pretreatment of bagasse. The IL and EG lignins contained no or trace amounts of carbohydrates, slightly lower hydrogen content but slightly higher oxygen contents than soda lignin. The IL and EG lignins contained more C-3 and C-5 reactive sites for Mannich reaction and had more p-hydroxypheny propane unit structures than soda lignin. Two-dimensional heteronuclear single quantum coherence (2D HSQC) nuclear magnetic resonance (NMR) identified the major substructural units in the lignins, and allowed differences among them to be studied. As EG lignins were extracted in very reactive environment, intermediate enol ethers were formed and led to cleavage reactions which were not apparent in the other lignins. 31P NMR and infra-red spectroscopy results showed that IL and EG lignins had lower total hydroxyl content than soda lignin, probably indicating that a higher degree of self-polymerisation occurred during bagasse pretreatment, despite the use of lower temperature and shorter reaction time. On the basis of the salient features of these lignins, potential applications were proposed.

Adjustable stiffness, external fixator for the rat femur osteotomy and segmental bone defect models

The mechanical environment around the healing of broken bone is very important as it determines the way the fracture will heal. Over the past decade there has been great clinical interest in improving bone healing by altering the mechanical environment through the fixation stability around the lesion. One constraint of preclinical animal research in this area is the lack of experimental control over the local mechanical environment within a large segmental defect as well as osteotomies as they heal. In this paper we report on the design and use of an external fixator to study the healing of large segmental bone defects or osteotomies. This device not only allows for controlled axial stiffness on the bone lesion as it heals, but it also enables the change of stiffness during the healing process in vivo. The conducted experiments have shown that the fixators were able to maintain a 5 mm femoral defect gap in rats in vivo during unrestricted cage activity for at least 8 weeks. Likewise, we observed no distortion or infections, including pin infections during the entire healing period. These results demonstrate that our newly developed external fixator was able to achieve reproducible and standardized stabilization, and the alteration of the mechanical environment of in vivo rat large bone defects and various size osteotomies. This confirms that the external fixation device is well suited for preclinical research investigations using a rat model in the field of bone regeneration and repair.