NMR-based metabonomics of bovine blood: an investigation into the effects of long term storage on plasma samples

Freezers in research institutions often contain a plethora of samples left over from studies performed years or even decades ago. Along with samples stored in biobanks, these could prove to be treasure troves for metabonomic research. Although the influence of sample handling and short to medium term storage on conventionally determined blood parameters has been reported, little is known about the effects of long term storage (years to decades) on plasma samples. The aim of this study was to investigate the influence of long term storage on the metabolite profile and to assess the value of archived samples for metabonomic studies. Heparinised plasma samples of 22 Holstein Friesian heifers that had been stored at -20°C for between 2 and 15 years were analysed using proton NMR spectroscopy and statistical analysis techniques. Lactate accounted for principal component one and explained 79.6% of variance between all spectra, but was not correlated with storage time. The highest correlation with storage time (R2 = 0.474) was found for betaine, with other metabolites (acetoacetate, histidines, glycerol, lipids and glucose) also showing moderate correlation (R2 values between 0.217 and 0.437). Our results indicate that samples stored for extended periods of time can potentially be used in metabolomics studies, if precautions are taken during data analysis

A comparison of nefazodone, the cognitive behavioral-analysis system of psychotherapy, and their combination for the treatment of chronic depression

Background Patients with chronic forms of major depression are difficult to treat, and the relative efficacy of medications and psychotherapy is uncertain. Methods We randomly assigned 681 adults with a chronic nonpsychotic major depressive disorder to 12 weeks of outpatient treatment with nefazodone (maximal dose, 600 mg per day), the cognitive behavioral-analysis system of psychotherapy (16 to 20 sessions), or both. At base line, all patients had scores of at least 20 on the 24-item Hamilton Rating Scale for Depression (indicating clinically significant depression). Remission was defined as a score of 8 or less at weeks 10 and 12. For patients who did not have remission, a satisfactory response was defined as a reduction in the score by at least 50 percent from base line and a score of 15 or less. Raters were unaware of the patients’ treatment assignments. Results Of the 681 patients, 662 attended at least one treatment session and were included in the analysis of response. The overall rate of response (both remission and satisfactory response) was 48 percent in both the nefazodone group and the psychotherapy group, as compared with 73 percent in the combined-treatment group (P Conclusions Although about half of patients with chronic forms of major depression have a response to short-term treatment with either nefazodone or a cognitive behavioral-analysis system of psychotherapy, the combination of the two is significantly more efficacious than either treatment alone

Multicentric case series of scuba diving fatalities: The role of intracardiac gaseous carbon dioxide in the forensic diagnosis.

Scuba diving fatalities post-mortem diagnosis presents a higher level of forensic complexity because of their occurrence in a non-natural human life environment. Scuba divers are equipped with diving gas to breathe underwater. It is essential for them to be fully trained in order to be able to manage their dive safely despite the varying increase of ambient pressure and temperature decrease. Throughout the dive, the inhaled diving gas is dissolved in the diver's tissues during the descent and if the decompression steps are not respected during the ascent, the balance between the dissolved gas and the tissues (including blood) is disrupted, leading to a gaseous release in the organism. Depending on the magnitude of this gaseous release, free gas can occur in blood and tissue. Venous or arterial gas embolism can also occur as a consequence of decompression sickness or barotraumatism. It can also induce drowsiness that consequently leads to drowning. As a result, the occurrence of gas in dead scuba divers is very complex to interpret, as is the difficulty to distinguish it from resuscitation maneuver artifacts or body decomposition. Although the literature is scarce in this domain, significant work has been done to provide a precise intracadaveric gas sampling method to enlighten the cause and circumstances of death during the dive. The aim of this study is to obtain higher statistical significance by collecting a number of cases to confirm the gas sampling protocol and analysis and gain more information about the cause of death and the events surrounding the fatality through the establishment of clear management guidelines

Association of different adverse life events with distinct patterns of depressive symptoms

Objective: The authors sought to determine whether, in a general population sample, different categories of adverse life events were associated with different patterns of depressive symptoms. Method: A total of 4,856 individuals (53% female) who experienced depressive symptoms in the previous year were assessed in up to four waves over a maximum of 12 years. At each wave, participants reported the severity of 12 symptoms disaggregated from the nine DSM-III-R criteria for major depression and the self-identified cause of these symptoms, which were classified into nine categories of adverse life events. Results: The patterns of de pressive symptoms associated with the nine categories of adverse life events differed significantly. Deaths of loved ones and romantic breakups were marked by high levels of sadness, anhedonia, appetite loss, and (for romantic breakups) guilt. Chronic stress and, to a lesser degree, failures were associated with fatigue and hypersomnia, but less so with sadness, anhedonia, and appetite loss. Those who reported that no adverse life events caused their dysphoric episodes reported fatigue, appetite gain, and thoughts of self-harm, but less sadness or trouble concentrating. These symptom patterns were found in a between-persons analysis of participants who had a single dysphoric episode, and they were replicated in an independent within-persons analysis of episode-specific symptom deviations among individuals with multiple episodes. Similar results were obtained when the sample was restricted to those meeting DSM-III-R diagnostic criteria for major depression. Conclusions: Depression is a pathoplastic syndrome. Different types of life events are related to different depressive symptom profiles. The results from the withinpersons analysis suggest that these relationships are causal. A central question in psychiatry has been whether variation in causal factors is related to variation in clinical presentation. While aspects of a syndrome may be central or core (pathogenic), other aspects may be pathoplastic, differing as a function of personal or precipitating factors (1). Much of the debate over the nosology of major depression-the "unitary" (2) versus "pluralistic" (3) viewpoints-can be seen as attempts to understand the pathogenic and pathoplastic nature of depression. What aspects of depression are invariant across individuals and across episodes within individuals, and what, if any, aspects depend on factors specific to the individual or episode? Attempts to understand this latter issue generally focus on differences in symptom profiles, precipitating causes, or both (4). The two most common subdivisions of major depression, melancholic (or endogenous) depression and atypical depression, are based on depressive symptom profiles that are thought to reflect stable interpersonal differences in how depression is manifested in different people. Similarly, diathesis-stress models suggest that distinct symptom profiles arise from interactions between specific cognitive styles and adverse life events (ALEs) to which people with the predisposing cognitive style are particularly vulnerable (5, 6). Both approaches predict that differences in depressive symptoms between episodes are due to stable interpersonal differences and that the symptom profiles of multiple episodes in an individual should be similar. However, several recent studies have found only modest stability in symptom profiles across episodes in the same individual (7-9), which raises the possibility that some of the differences in depressive symptoms across episodes are caused by situational factors. Research on college students (10, 11) has shown relationships between broad ALE categories and distinct depressive symptom patterns. Social losses, such as deaths of loved ones and romantic breakups, were associated with more emotional pain, crying, desire for social support, and appetite loss. Wintertime blues were associated with symptoms typical of seasonal affective disorder. Failures and chronic stress were associated with more guilt, hopelessness, and fatigue

Mechanical loading of stem cells for improvement of transplantation outcome in a model of acute myocardial infarction: the role of loading history

Stem cell therapy for tissue repair is a rapidly evolving field and the factors that dictate the physiological responsiveness of stem cells remain under intense investigation. In this study we hypothesized that the mechanical loading history of muscle-derived stem cells (MDSCs) would significantly impact MDSC survival, host tissue angiogenesis, and myocardial function after MDSC transplantation into acutely infarcted myocardium. Mice with acute myocardial infarction by permanent left coronary artery ligation were injected with either nonstimulated (NS) or mechanically stimulated (MS) MDSCs. Mechanical stimulation consisted of stretching the cells with equibiaxial stretch with a magnitude of 10% and frequency of 0.5 Hz. MS cell-transplanted hearts showed improved cardiac contractility, increased numbers of host CD31 + cells, and decreased fibrosis, in the peri-infarct region, compared to the hearts treated with NS MDSCs. MS MDSCs displayed higher vascular endothelial growth factor expression than NS cells in vitro. These findings highlight an important role for cyclic mechanical loading preconditioning of donor MDSCs in optimizing MDSC transplantation for myocardial repair

A quantitative theory-versus-experiment comparison for the intense laser dissociation of H2+

A detailed theory-versus-experiment comparison is worked out for H$_2^+$ intense laser dissociation, based on angularly resolved photodissociation spectra recently recorded in H.Figger's group. As opposite to other experimental setups, it is an electric discharge (and not an optical excitation) that prepares the molecular ion, with the advantage for the theoretical approach, to neglect without lost of accuracy, the otherwise important ionization-dissociation competition. Abel transformation relates the dissociation probability starting from a single ro-vibrational state, to the probability of observing a hydrogen atom at a given pixel of the detector plate. Some statistics on initial ro-vibrational distributions, together with a spatial averaging over laser focus area, lead to photofragments kinetic spectra, with well separated peaks attributed to single vibrational levels. An excellent theory-versus-experiment agreement is reached not only for the kinetic spectra, but also for the angular distributions of fragments originating from two different vibrational levels resulting into more or less alignment. Some characteristic features can be interpreted in terms of basic mechanisms such as bond softening or vibrational trapping.Comment: submitted to PRA on 21.05.200

Interventional low-dose azithromycin attenuates cigarette smoke-induced emphysema and lung inflammation in mice

Cigarette smoke (CS)-induced emphysema is an important contributor to chronic obstructive pulmonary disease (COPD). We have shown the efficacy of azithromycin in reducing airway inflammation in COPD and in reducing exacerbations in severe asthma; however, the effects of long-term azithromycin on emphysema development have not been shown. We employed live animal imaging to monitor emphysema-like development and the effects of interventional azithromycin treatment in CS-exposed mice. BALB/c mice (female, 10 weeks; n = 10) were exposed to CS for 1 hr twice daily, 5 days/week, and for 12 weeks (CS). Half were cotreated with low-dose azithromycin during weeks 7-12 (CS + Azi; 0.2 mg kg-1  day-1 ). Microcomputed tomography (CT) and magnetic resonance imaging (MRI) scans were acquired longitudinally. Histological examinations were performed post mortem (mean linear intercept (Lm) and leukocyte infiltration). CS increased median Lm (CS: 42.45 µm versus control: 34.7 µm; p = .0317), this was recovered in CS + Azi mice (33.03 µm). Average CT values were reduced in CS mice (CS: -399.5 Hounsfield units (HU) versus control: -384.9 HU; p = .0286) but not in CS + Azi mice (-377.3 HU). CT values negatively correlated with Lm (r = -.7972; p = .0029) and T2 -weighted MRI (r = -.6434; p = .0278). MRI also showed significant CS-induced inflammatory changes that were attenuated by azithromycin in the lungs, and positively correlated with Lm (r = .7622; p = .0055) and inflammatory foci counts (r = .6503; p = .0257). Monitoring of emphysema development is possible via micro-CT and MRI. Interventional azithromycin treatment in CS-exposed mice attenuated the development of pulmonary emphysema-like changes.Matthew G. Macowan, Hong Liu, Miranda Ween, Rhys Hamon, Hai B. Tran Sandra Hodge ... et al

Ultrafast carrier relaxation in GaN, In_(0.05)Ga_(0.95)N and an In_(0.05)Ga_(0.95)/In_(0.15)Ga_(0.85)N Multiple Quantum Well

Room temperature, wavelength non-degenerate ultrafast pump/probe measurements were performed on GaN and InGaN epilayers and an InGaN multiple quantum well structure. Carrier relaxation dynamics were investigated as a function of excitation wavelength and intensity. Spectrally-resolved sub-picosecond relaxation due to carrier redistribution and QW capture was found to depend sensitively on the wavelength of pump excitation. Moreover, for pump intensities above a threshold of 100 microJ/cm2, all samples demonstrated an additional emission feature arising from stimulated emission (SE). SE is evidenced as accelerated relaxation (< 10 ps) in the pump-probe data, fundamentally altering the re-distribution of carriers. Once SE and carrier redistribution is completed, a slower relaxation of up to 1 ns for GaN and InGaN epilayers, and 660 ps for the MQW sample, indicates carrier recombination through spontaneous emission.Comment: submitted to Phys. Rev.

Salt marsh shoreline geomorphology influences the success of restored oyster reefs and use by associated fauna

Restoration is increasingly implemented as a strategy to mitigate global declines in biogenic habitats, such as salt marshes and oyster reefs. Restoration efforts could be improved if we knew how site characteristics at landscape scales affect the ecological success of these foundation species. In this study, we determined how salt marsh shoreline geomorphologies (e.g. with variable hydrodynamic energy, fetch, erosion rates, and slopes) affect the success of restored intertidal oyster reefs, as well as how fauna utilize restored reefs and forage along marsh habitats. We constructed oyster reefs along three marsh shoreline geomorphologies in May 2012: 1) “creek” (small-fetch, gradual-sloped shoreline), “ramp” (large-fetch, gradual-sloped shoreline), and “scarp” (large-fetch, steep-sloped shoreline). Following recruitment, oyster spat density was greatest on ramp reefs; however, 2 years later, the highest adult oyster densities were found on creek reefs. Total nekton and blue crab catch rates in trawl nets were highest in the creek, while piscivore catch rates in gill nets were highest along the scarp shoreline. We found no difference in predation on snails in the salt marsh behind constructed reef and nonconstructed reference sites, but there were more snails consumed in the creek shoreline, which corresponded with the distribution of their major predator—blue crabs. We conclude that oyster reef construction was most successful for oysters in small-fetch, gradual-sloped, creek environments. However, nekton abundance did not always follow the same trends as oyster density, which could suggest constructed reefs may offer similar habitat-related functions (prey availability and refuge) already present along existing salt marsh borders