'Would I risk it again?' The long-term impacts of a traumatic birth, as experienced by fathers

BACKGROUND

Extensive research has explored the impact of traumatic births on mothers, capturing enduring adverse outcomes as well as post-traumatic growth. The literature on fathers' experiences of birth trauma is more limited and little is known of the ongoing impact. The present study aimed to investigate the long-term effects of attending a traumatic birth.

METHOD

Semi-structured interviews were completed with fathers who identified as having a traumatic birth experience two or more years ago. Thematic analysis was conducted on eight interview transcripts.

RESULTS

Despite the time since the birth trauma, fathers described ongoing impact, which is captured in five themes. Four of these focus on the negative impacts: their attempts to cope by boxing away emotions, which they thought they should not feel; anxieties over having further children; negative effects on parenting; and ongoing distress or negative impact on their wellbeing. The final theme highlighted some positives from the experience, primarily a strengthened relationship with their partner.

CONCLUSIONS

Traumatic birth can result in fathers experiencing difficulties beyond the perinatal period, whilst thinking that they should not feel or discuss their distress. As a result of a traumatic birth fathers can experience ongoing guilt and poor mental health, which may lead them to delay subsequent pregnancies. Most participants had not accessed support regarding the traumatic birth, instead coping by trying to avoid their memories and emotional reaction. These findings highlight the need for increased acknowledgement of the impact of birth trauma and intervention for fathers, during and after the perinatal period.

Women's experience of post-traumatic growth following a traumatic birth: an interpretive phenomenological analysis

BACKGROUND

Approximately 3-5% of women experience post-traumatic stress disorder following birth; positive experiences that can follow traumatic birth are under-researched.

AIMS AND OBJECTIVES

To explore how women experience post-traumatic growth following a traumatic birth.

METHODS

Interpretative Phenomenological Analysis was used to explore experiences of women who self-identified as having found positive benefits through coping with a traumatic birth. Eight women who had birthed in the past five years in the UK were recruited online and interviewed face-to-face.

RESULTS

Three superordinate themes were developed: 'The total opposite to what I'd expected' (participants' struggle to understand and integrate their birth experience in the postnatal period); 'I see it a bit differently now' (processes experienced in coming to a place of growth); and 'A much better place' (experienced growth 'outcomes').

DISCUSSION

Faced with shattered assumptions whereby their birth experiences contrasted with their expectations, participants felt their identities as women and mothers were challenged. In overcoming these challenges, participants described actively striving to cope and make sense of their experience. Multiple factors facilitated this, notably partner support, telling their birth story, acknowledging the impact and developing a compassionate narrative. Although growth was experienced in ways commonly reported by survivors of challenging life events, some aspects appeared pertinent to birth trauma.

CONCLUSIONS

Widening our understanding of the range of experiences following traumatic birth and making these narratives public may offer hope for some women and families and inform health professionals' education and practice. Further research would be needed before advocating interventions to foster post-traumatic growth.

'A more human approach … I haven't found that really': experiences of hoarding difficulties and seeking help

BACKGROUND AND AIMS

People with hoarding behaviours often struggle to engage in treatment. This study aimed to explore the experiences of a sample of people who identify as engaging in hoarding behaviours and who are seeking support. Exploring motivation to seek help, the barriers those who hoard face in accessing support and what facilitates accepting help, can aid understanding of how best to intervene.

METHOD

Eight individuals who self-identified as seeking help in relation to hoarding behaviours were recruited via social media and support groups. Interviews were conducted by telephone or video call, before being transcribed and analysed using interpretative phenomenological analysis.

RESULTS

Participants described complex help-seeking narratives and reported continued ambivalence about addressing their hoarding behaviours. The four group experiential themes identified were Wrestling with identity; Who can I trust?; Services don't fit; and Being overlooked: 'they're too busy looking at the thing, not the person'. Difficulties trusting others and services were identified; services were experienced as rejecting and many participants sought help for problems other than their hoarding. Problems accessing appropriate help for hoarding were predominant in the narratives, although participants who had accessed peer support described this as valuable.

CONCLUSIONS

There are both internal (e.g. fear of judgement; feeling overwhelmed) and external (e.g. service gaps) barriers that make finding useful help for hoarding behaviours very difficult. Services may facilitate those seeking help by taking a compassionate and person-centred approach to hoarding problems.

Non-birthing mothers' experiences of perinatal anxiety and depression: Understanding the perspectives of the non-birthing mothers in female same-sex parented families

OBJECTIVE

Partners of birthing mothers can themselves experience perinatal mental health (PMH) difficulties. Despite birth rates increasing amongst LGBTQIA+ communities and the significant impact of PMH difficulties, this area is under-researched. This study aimed to examine the experiences of perinatal depression and anxiety of non-birthing mothers in female same-sex parented families.

DESIGN

Interpretative Phenomenological Analysis (IPA) was used to explore the experiences of non-birthing mothers who self-identified as having experienced perinatal anxiety and/or depression.

SETTING AND PARTICIPANTS

Sevenparticipants were recruited from online and local voluntary and support networks for LGBTQIA+ communities and for PMH. Interviews were in-person, online or via telephone.

MEASUREMENTS AND FINDINGS

Six themes were generated. Distress was characterised by feelings of "Failure and Inadequacy in Role" (i.e., parent, partner and individual) and "Powerlessness and Intolerable Uncertainty" in their parenting journey. These feelings were reciprocally influenced by perceptions of the "Legitimacy of (Di)stress as a Non-birthing Parent", which impacted help-seeking. Stressors that contributed to these experiences were: "Parenting Without" a parental role template, social recognition and safety, and parental connectedness; and "Changed Relationship Dynamics" with their partner. Finally,participants spoke about "Moving Forward" in their lives.

KEY CONCLUSIONS

Some findings are consistent with the literature on paternal mental health, including parents' emphasis on protecting their family and experiencing services as focusing on the birthing parent. Others appeared distinct or amplified for LGBTQIA+ parents, including the lack of a defined and socially recognised role; stigma concerning both mental health and homophobia; exclusion from heteronormative healthcare systems; and the importance placed on biological connectedness.

IMPLICATIONS FOR PRACTICE

Culturally competent care is needed to tackle minority stress and recognise diverse family forms.

Digital Intervention for Problematic Smartphone Use

Smartphones have become the primary devices for accessing the online world. The potential for smartphone use to become problematic has come into increasing focus. Students and young adults have been shown to use their smartphones at high rates and may be at risk for problematic use. There is limited research evaluating interventions for problematic smartphone use. The present research aimed to develop and evaluate a digital intervention for problematic smartphone use in a student population. A mixed-method case series design was used. The participants were 10 students with mild–moderate dependency on the online world (measured via a self-report questionnaire). An intervention comprising goal setting, personalised feedback, mindfulness, and behavioural suggestions was delivered via a smartphone application. Time spent on smartphones was measured objectively through the same application. Changes in problematic technology use, wellbeing, mindfulness, and sleep were also evaluated. The findings indicate that the intervention resulted in a reduction in self-reported problematic smartphone use, but not screen time. The findings also indicate that over the course of participation, there was a positive influence on wellbeing, online dependency, mindfulness, and sleep. However, the mechanisms of change could not be determined. The study provides preliminary evidence that a light-touch, smartphone-delivered package is an acceptable and effective intervention for students wishing to better manage their problematic smartphone use.

Meta-analysis and Meta-regression of Cognitive Behavioral Therapy for Psychosis (CBTp) Across Time: The Effectiveness of CBTp has Improved for Delusions

Published research shows small-to-medium effects of Cognitive Behavioral Therapy for Psychosis (CBTp) on reducing psychotic symptoms. Given the on-going development of CBTp interventions, the aim of this systematic review is to examine whether the effectiveness of CBTp has changed across time. MEDLINE, EMBASE, PsycINFO, and CENTRAL were searched for randomized controlled trials examining CBTp interventions targeting positive and/or negative symptoms vs treatment as usual. Four meta-analyses were carried out to examine the effectiveness of CBTp for: positive symptoms; delusions; hallucinations; and negative symptoms. Four meta-regressions examined whether the effectiveness of CBTp changed across time for these groups of symptoms. A total of 28 studies (n = 2698) yielded a pooled g of −0.24 (95% confidence interval [CI] −0.32, −0.16, P < .001) favoring CBTp for positive symptoms, with nonsignificant heterogeneity (Q = 26.87, P = .47; I2 =0%); 13 studies (n = 890) yielded a pooled g of −0.36 (95% CI −0.59, −0.13, P = .002) for delusions, with substantial heterogeneity (Q = 31.99, P = .001; I2 =62%); 16 studies (n = 849) yielded a pooled g of −0.26 (95% CI −0.42, −0.11, P < .001) for hallucinations, with nonsignificant heterogeneity (Q = 18.10, P = .26; I2 =17%); 19 studies (n = 1761) yielded a pooled g of −0.22 (95% CI −0.33, −0.12, P < .001) for negative symptoms, with nonsignificant heterogeneity (Q = 20.32, P = .32, I2 =11%). Meta-regressions indicated a significant effect of year on the effectiveness of CBTp only for delusions (F[1, 11] = 5.99, P = .032; R2 = 0.594); methodological quality did not effect this finding. Findings indicate small-to-medium effects of CBTp for psychotic symptoms, with increasing effectiveness across time for delusions.

The Impact of Therapists' Responses to Resistance to Change: A Sequential Analysis of Therapist Client Interactions in Motivational Interviewing

AIMS

The study aims to examine how therapists trained in motivational interviewing (MI) respond to resistance and whether this has an impact on subsequent client speech.

METHODS

Fifty recorded Motivational Enhancement Therapy sessions were examined using a sequential behavioural coding method for speech. Client counter-change talk formed the baseline for coding and categorizing subsequent therapist speech and the following client speech. Transitional analysis identified the probable occurrence of specific therapist and client utterances at each stage.

RESULTS

Following client expressed resistance or counter-change talk, MI consistent therapist utterances were most commonly observed. A moderate to strong predictive relationship was found between MI-consistent therapist speech and subsequent client change talk. A moderate predictive relationship was found between therapist MI-consistent behaviours and client ambivalence. A moderate to strong predictive relationship was found between MI-inconsistent therapist speech and subsequent client counter-change talk and a weak negative predictive relationship was found between MI-inconsistent therapist speech and client expressed ambivalence.

CONCLUSIONS

In the face of initial expressed resistance to change, MI-consistent therapist speech appears to increase subsequent client utterances regarding intentions to change drinking behaviour.

Clients' experience of change: An exploration of the influence of reformulation tools in cognitive analytic therapy

Case formulation is considered important in both the development of the therapeutic relationship and in starting the process of therapeutic change. Cognitive analytic therapy (CAT) describes the developmental origins and maintenance of a client's problems in both written (reformulation letter) and diagrammatic form (sequential diagrammatic reformulation). This study aimed to investigate the effects of these reformulation tools on insight and symptom change. A small-N repeated measures design was employed with quantitative and qualitative measures collected from six therapist/client dyads. Participating therapists kept a record of their delivery of CAT reformulation tools. Participating clients completed the insight subscale of the Self-Reflection and Insight Scale every fourth session and the Clinical Outcomes in Routine Evaluation-10 every session. Qualitative data from client change interviews regarding their experiences of CAT and attributions of change was explored using template analysis. Participants demonstrated improvements (symptom reduction and insight increases) over the course of the intervention. Administration of reformulation tools did not consistently result in significant changes on insight and symptom measures. However, the tools were identified by participants as leading to insight and emotional change within the context of a good therapeutic relationship. These findings suggest that a genuine therapeutic relationship is an important change mechanism operating through, and strengthened by, CAT-specific tools.

Mesenchymal stromal cell therapies: potential and pitfalls for ARDS

Mesenchymal stem/stromal cells (MSCs) offer considerable promise as a novel therapeutic strategy for acute respiratory distress syndrome (ARDS). MSCs may be able to "reprogramme" the immune response to reduce destructive inflammatory elements while preserving the host response to pathogens. In addition, MSCs may be able to enhance the repair and resolution of lung injury. Resolution of ARDS is impeded by destruction of the integrity of the epithelial barrier, which inhibits alveolar fluid clearance and depletes surfactant. MSCs appear to restore epithelial and endothelial function, via both paracrine and cell contact dependent effects. ARDS is frequently a component of a generalized process resulting in dysfunction and failure of multiple organs. MSCs have been demonstrated to decrease injury and/or restore function in other organs, including the kidney, liver and heart. MSCs may directly attenuate bacterial sepsis, the commonest and most severe cause of ALI/ARDS. The fact that MSCs are in clinical studies for a wide range of disease processes is a clear advantage for translating MSCs to clinical testing in patients with ARDS. However, some important knowledge gaps exist that may impede clinical translation. The ultimate success of MSCs as a therapy for patients with ARDS will likely be dependent on a greater knowledge of their mechanisms of action and the determination of the optimal strategies for their use in the clinical setting.

Pulmonary overexpression of inhibitor κBα decreases the severity of ventilator-induced lung injury in a rat model

BACKGROUND

Activation of the nuclear factor-κB (NF-κB) pathway is central to the pathogenesis of lung injury and inflammation. We determined whether targeted overexpression of inhibitor-κBα (IκBα) in the lung could decrease the severity of ventilator-induced lung injury (VILI).

METHODS

Anaesthetized adult male Sprague-Dawley rats were randomly allocated to undergo intratracheal instillation of: (i) vehicle alone (surfactant, n=10); (ii) 1×10(10) adeno-associated virus encoding IκBα (AAV-IκBα, n=10); (iii) 5×10(10) AAV-IκBα (n=10); and (iv) 1×10(10) AAV-Null (n=5). This was followed by 4 h of injurious mechanical ventilation. Subsequent experiments examined the effect of IκBα overexpression in animals undergoing 'protective' mechanical ventilation.

RESULTS

IκBα overexpression increased survival duration at both the lower [3.8 h (0.4)] and higher [3.6 h (0.7)] doses compared with vehicle [2.7 h (1.0)] or the null transgene [2.2 h (0.8)]. IκBα overexpression reduced the alveolar-arterial oxygen gradient (kPa) at both the lower [53 (21)] and higher [52 (19)] doses compared with vehicle [75 (8.5)] or the null transgene [70 (15)], decreased alveolar neutrophil infiltration, and reduced alveolar concentrations of interleukin (IL)-1β and IL-10. The lower IκBα dose was as effective as the higher dose. IκBα overexpression had no effect in the setting of protective lung ventilation.

CONCLUSIONS

Inhibition of pulmonary NF-κB activity by IκBα overexpression reduced the severity of VILI in a rat model.

Fast Variability of Tera–Electron Volt γ Rays from the Radio Galaxy M87

The detection of fast variations of the tera-electron volt (TeV) (10(12) eV) gamma-ray flux, on time scales of days, from the nearby radio galaxy M87 is reported. These variations are about 10 times as fast as those observed in any other wave band and imply a very compact emission region with a dimension similar to the Schwarzschild radius of the central black hole. We thus can exclude several other sites and processes of the gamma-ray production. The observations confirm that TeV gamma rays are emitted by extragalactic sources other than blazars, where jets are not relativistically beamed toward the observer.

HESS observations of the galactic center region and their possible dark matter interpretation

The detection of gamma rays from the source HESS J1745-290 in the Galactic Center (GC) region with the High Energy Spectroscopic System (HESS) array of Cherenkov telescopes in 2004 is presented. After subtraction of the diffuse gamma-ray emission from the GC ridge, the source is compatible with a point source with spatial extent less than 1.2;{'}(stat) (95% C.L.). The measured energy spectrum above 160 GeV is compatible with a power law with photon index of 2.25+/-0.04(stat)+/-0.10(syst) and no significant flux variation is detected. It is finally found that the bulk of the very high energy emission must have non-dark-matter origin.

A low level of extragalactic background light as revealed by γ-rays from blazars

The diffuse extragalactic background light consists of the sum of the starlight emitted by galaxies through the history of the Universe, and it could also have an important contribution from the 'first stars', which may have formed before galaxy formation began. Direct measurements are difficult and not yet conclusive, owing to the large uncertainties caused by the bright foreground emission associated with zodiacal light. An alternative approach is to study the absorption features imprinted on the gamma-ray spectra of distant extragalactic objects by interactions of those photons with the background light photons. Here we report the discovery of gamma-ray emission from the blazars H 2356 - 309 and 1ES 1101 - 232, at redshifts z = 0.165 and z = 0.186, respectively. Their unexpectedly hard spectra provide an upper limit on the background light at optical/near-infrared wavelengths that appears to be very close to the lower limit given by the integrated light of resolved galaxies. The background flux at these wavelengths accordingly seems to be strongly dominated by the direct starlight from galaxies, thus excluding a large contribution from other sources-in particular from the first stars formed. This result also indicates that intergalactic space is more transparent to gamma-rays than previously thought.

Discovery of very-high-energy γ-rays from the Galactic Centre ridge

The source of Galactic cosmic rays (with energies up to 10(15) eV) remains unclear, although it is widely believed that they originate in the shock waves of expanding supernova remnants. At present the best way to investigate their acceleration and propagation is by observing the gamma-rays produced when cosmic rays interact with interstellar gas. Here we report observations of an extended region of very-high-energy (> 10(11) eV) gamma-ray emission correlated spatially with a complex of giant molecular clouds in the central 200 parsecs of the Milky Way. The hardness of the gamma-ray spectrum and the conditions in those molecular clouds indicate that the cosmic rays giving rise to the gamma-rays are likely to be protons and nuclei rather than electrons. The energy associated with the cosmic rays could have come from a single supernova explosion around 10(4) years ago.

Discovery of Very High Energy Gamma Rays Associated with an X-ray Binary

X-ray binaries are composed of a normal star in orbit around a neutron star or stellar-mass black hole. Radio and x-ray observations have led to the presumption that some x-ray binaries called microquasars behave as scaled-down active galactic nuclei. Microquasars have resolved radio emission that is thought to arise from a relativistic outflow akin to active galactic nuclei jets, in which particles can be accelerated to large energies. Very high energy gamma-rays produced by the interactions of these particles have been observed from several active galactic nuclei. Using the High Energy Stereoscopic System, we find evidence for gamma-ray emission of >100 gigaelectron volts from a candidate microquasar, LS 5039, showing that particles are also accelerated to very high energies in these systems.

A new population of very high energy gamma-ray sources in the Milky Way

Very high energy gamma-rays probe the long-standing mystery of the origin of cosmic rays. Produced in the interactions of accelerated particles in astrophysical objects, they can be used to image cosmic particle accelerators. A first sensitive survey of the inner part of the Milky Way with the High Energy Stereoscopic System (HESS) reveals a population of eight previously unknown firmly detected sources of very high energy gamma-rays. At least two have no known radio or x-ray counterpart and may be representative of a new class of "dark" nucleonic cosmic ray sources.

High-energy particle acceleration in the shell of a supernova remnant

A significant fraction of the energy density of the interstellar medium is in the form of high-energy charged particles (cosmic rays). The origin of these particles remains uncertain. Although it is generally accepted that the only sources capable of supplying the energy required to accelerate the bulk of Galactic cosmic rays are supernova explosions, and even though the mechanism of particle acceleration in expanding supernova remnant (SNR) shocks is thought to be well understood theoretically, unequivocal evidence for the production of high-energy particles in supernova shells has proven remarkably hard to find. Here we report on observations of the SNR RX J1713.7 - 3946 (G347.3 - 0.5), which was discovered by ROSAT in the X-ray spectrum and later claimed as a source of high-energy gamma-rays of TeV energies (1 TeV = 10(12) eV). We present a TeV gamma-ray image of the SNR: the spatially resolved remnant has a shell morphology similar to that seen in X-rays, which demonstrates that very-high-energy particles are accelerated there. The energy spectrum indicates efficient acceleration of charged particles to energies beyond 100 TeV, consistent with current ideas of particle acceleration in young SNR shocks.

Effects on lung function, symptoms, and bronchial hyperreactivity of low-dose inhaled beclomethasone dipropionate given with HFA-134a or CFC propellant

The aim of this study was to compare the efficacy of BDP 200 microg bid via metered dose inhaler, using HFA-134a (Chiesi Farmaceutici S.p.A., Parma, Italy) versus CFC (Becotide, Allen & Hanburys, U.K.) as a propellant. 172 adult patients (86 in each group) with stable mild persistent asthma who completed a 7-day run-in period were randomized to receive a 6-week treatment in a double-blind, double dummy, parallel-group design; 164 patients completed the study. Morning and evening PEFR, use of rescue salbutamol, number of day-time and night-time asthma attacks, number of night-time awakenings and clinical symptoms were recorded daily on a diary card. Pulmonary function tests (FEV(1), FVC, PEFR, and MEF(50)) were measured at the clinic before and after the 1-week run-in period, and after 3 and 6 weeks of treatment. A challenge test with inhaled methacholine was completed at baseline and at the end of the treatment period to assess potential bronchial hyper-reactivity in a subgroup of subjects (n = 65; 34 HFA, 31 CFC). In accordance with asthma of mild severity (FEV(1) predicted over 90% in both groups), a small improvement in lung function compared to baseline was seen for both treatments, significantly for FEV(1) in BDP HFA and MEF(50) in both groups. The two formulations of BDP had similar efficacy for the primary outcome variable morning PEFR (ITT population mean difference 5.8 L/min; C.I. -4.9 to +16.5) as well as for the secondary outcomes of evening PEFR and clinic FEV(1). There were small improvements in methacholine PD(20) and PC20 in both groups, with no significant difference between treatments. A total of 22 and 19 drug-related adverse events were reported in the BDP HFA and CFC groups, respectively; most events were of seasonal nature or were local effects due to the use of inhaled corticosteroids. It can be concluded that the newly developed formulation of BDP given via HFA-134a seems to provide similar asthma control, compared with the same low daily dose of the active drug delivered via CFC. Further studies are needed using higher doses in moderate to severe asthma to confirm these preliminary findings.

Mitochondrial and peroxisomal beta-oxidation capacities of organs from a non-oilseed plant

Until recently, beta-oxidation was believed to be exclusively located in the peroxisomes of all higher plants. Whilst this is true for germinating oilseeds undergoing gluconeogenesis, evidence demonstrating mitochondrial beta-oxidation in other plant systems has refuted this central dogma of plant lipid metabolism. This report describes a comparative study of the dual mitochondrial and peroxisomal beta-oxidation capacities of plant organs. Oxidation of [1-(14)C] palmitate was measured in the cotyledons, plumules and radicles of Pisum sativum L., which is a starchy seed, over a 14 day period from the commencement of imbibition. Respiratory chain inhibitors were used for differentiating between mitochondrial and peroxisomal beta-oxidation. Peroxisomal beta-oxidation gave a steady, baseline rate and, in the early stages of seedling development, accounted for 70-100% of the beta-oxidation observed. Mitochondrial beta-oxidation gave peaks of activity at days 7 and 10-11, accounting for up to 82% of the total beta-oxidation activity at these times. These peaks coincide with key stages of seedling development and were not observed when normal development was disrupted by growth in the dark. Peroxisomal beta-oxidation was unaffected by etiolation. Since mitochondrial beta-oxidation was overt only during times of intense biosynthetic activity it might be switched on or off during seedling development. In contrast, peroxisomes maintained a continuous, low beta-oxidation activity that could be essential in removing harmful free fatty acids, e.g. those produced by protein and lipid turnover.

Accumulation of atmospheric and sedimentary PCBs and toxaphene in a Lake Michigan food web

Seston, sediment, settling organic matter, and food web members were collected from Grand Traverse Bay, Lake Michigan, between April 1997 and September 1998 to examine PCB and toxaphene biomagnification. Stable isotopes of nitrogen and carbon were analyzed in samples and used to establish trophic structure of the food web and to determine the importance of atmospheric versus sedimentary sources in delivering PCBs to the food web. Nitrogen isotopes were confounded by multiple variables in this system, particularly seasonal variation, and did not display a simple pattern of enrichment among trophic levels. However, delta13C displayed little seasonal variation and was positively correlated with PCB concentrations among food web members (r2 = 0.69). Plots of delta13C vs PCBs separate food web members into three distinct groupings comprised of invertebrates, primary forage fish, and predatory fish. Stable isotope values of the primary organic sources indicate that the atmosphere, and not the sediment, is the most likely source of PCBs to the food web of Lake Michigan. Additionally, we suggest that seston may be important in delivering PCBs to pelagic food web members and species that receive a majority of their nutrition through pelagic sources. In contrast, settling particles are implicated in delivering PCBs to benthic organisms and Mysis relicta.

Acyl-CoA dehydrogenase activity in pea cotyledon tissue during germination and initial growth

Acyl-CoA dehydrogenase activity has been measured in homogenates of post-imbibition to 14-day-old hydroponically grown pea seeds at daily intervals, using C(4), C(12) and C(16) acyl-CoA substrates. The activity peaks of the different chain-length acyl-CoA dehydrogenases did not transpose at all points and the ratios of the chain-length activities were not constant. It therefore has to be concluded that more than one dehydrogenase is present in pea mitochondria. There was a post-imbibition initial surge of activity with short- and mid-chain-length substrates. The C(16)-handling enzyme first peaked at 3-4 days, which coincided with the onset of plumule unfurling and greening. Further peaks were observed with all three substrates, coinciding with secondary root formation and leaf enlargement and later with cotyledon degeneration. Overall activity showed that the long-chain acyl-CoA dehydrogenase was much more active than the short-chain acyl-CoA dehydrogenase.

Contribution of mitochondria and peroxisomes to palmitate oxidation in pea tissues

Total, mitochondrial and peroxisomal palmitate oxidation capacities were compared in pea, from the dry seed to 14 days after imbibition. Total beta-oxidation varied over the measured time period and showed four peaks of activity at day 2, days 5-6, day 10 and days 12-13. The contribution of peroxisomal and mitochondrial beta-oxidation to this overall beta-oxidation varied. Over the first 48 h of seed germination, peroxisomal beta-oxidation accounted for 80-100% of the total observed beta-oxidation. The larger peaks of beta-oxidation at days 5-6, day 10 and days 12-13 were due primarily to mitochondrial beta-oxidation activity, which accounted for 70-90% of the observed total beta-oxidation at these times. The peaks of activity are related to observed stages in seedling development.

Pea chloroplast carnitine acetyltransferase

The purpose of this study was to resolve the controversy as to whether or not chloroplasts possess the enzyme carnitine acetyltransferase (CAT) and whether the activity of this enzyme is sufficient to support previously reported rates of fatty acid synthesis from acetylcarnitine. CAT catalyses the freely reversible reaction: carnitine + short-chain acylCoA <--> short-chain acylcarnitine + CoASH. CAT activity was detected in thc chloroplasts of Pisum sativum L. With membrane-impermeable acetyl CoA as a substrate. activity was only detected in ruptured chloroplasts and not with intact chloroplasts, indicating that the enzyme was located on the stromal side of the envelope. In crude preparations, CAT could only be detected using a sensitive radioenzymatic assay due to competing reactions from other enzymes using acetyl CoA and large amounts of ultraviolet-absorbing materials. After partial purification of the enzyme, CAT was detected in both the forward and reverse directions using spectrophotometric assays. Rates of 100 nmol of product formed per minute per milligram of protein were obtained, which is sufficient to support reported fatty acid synthesis rates from acetylcarnitine. Chloroplastic CAT showed optimal activity at pH 8.5 and had a high substrate specificity, handling C2-C4 acyl CoAs only. We believe that CAT has been satisfactorily demonstrated in pea chloroplasts.

Simultaneous X-Ray and TeV Observations of a Rapid Flare from Markarian 421

Mrk 421 was observed for about 2 days with BeppoSAX in 1998 April as part of a worldwide multiwavelength campaign. A large, well-defined flare was observed in X-rays. The same flare was observed simultaneously at TeV energies by the Whipple Observatory gamma-ray telescope. These data provide (1) the first evidence that the X-ray and TeV intensities are well correlated on timescales of hours and (2) the first exactly simultaneous X-ray and TeV spectra. The results imply that the X-ray and TeV photons derive from the same region and from the same population of relativistic electrons. The physical parameters deduced from a homogeneous synchrotron self-Compton model for the spectral energy distribution yield electron cooling times close to the observed variability timescales.

Synthetic phospho-oligosaccharide fragments of lipophosphoglycan as acceptors for Leishmania major alpha-D-mannosylphosphate transferase

Protozoan parasites of the genus Leishmania synthesise lipophosphoglycans, phosphoglycans and proteophosphoglycans that contain phosphosaccharide-repeat units of [-6Gal beta 1-4Man alpha 1-P-]. In this study, a GDP-Man-dependent alpha-mannosylphosphate-transferase activity was detected in washed Leishmania major membranes using synthetic phospho-oligosaccharide fragments of lipophosphoglycan as acceptor substrates. The divalent-cation-dependent alpha-mannosylphosphate-transferase activity had an apparent K(m) for GDP-Man of about 15-20 microM and a pH optimum of 7.0. The activity showed a requirement for a non-reducing terminal beta Gal residue and for one or more phosphodiester units preceding the acceptor site. Based on these results, the activity may be defined as a GDP-Man: Gal beta 1-4Man alpha 1-P-R alpha-mannosylphosphate-transferase. This acceptor specificity is consistent with a role for the alpha-mannosylphosphate transferase in the elongation of phosphosaccharide-repeat domains of Leishmania glycoconjugates rather than in the priming of these domains. An identical or similar activity must exist in the amastigote forms of the Leishmania that produce and secrete proteophosphoglycan material and the activity therefore represents a feasible target for the development of chemotherapeutics.

The developmental regulation and biosynthesis of GPI-related structures in Leishmania parasites

Most macromolecules on the surface of Leishmania parasites, including the major surface proteins and a complex lipophosphoglycan (LPG) are anchored to the plasma membrane via GPI glycolipids. Free glycoinositol-phospholipids (GIPLs) which are not linked to protein or phosphoglycan are also abundant in the plasma membrane. From structural and metabolic labeling studies it is proposed that most Leishmania species express three distinct pathways of GPI biosynthesis. Some of these pathways (i.e. those involved in the protein and LPG anchor biosynthesis) are down-regulated during the differentiation of the insect (promastigote) stage to the mammalian (amastigote) stage. In contrast, the GIPLs are expressed in high copy number in both developmental stages. Based on analysis of the lipid moieties of the different GPI species it is possible that the pathways of GPI anchor and GIPL biosynthesis are located in different subcellular compartments. The relative flux through the GIPL and LPG biosynthetic pathways has been examined in L. major promastigotes. These studies showed that while the rate of synthesis of the GIPLs and LPG is similar, LPG is shed more rapidly from the plasma membrane and has a higher turnover. The possible metabolic relationship between the GIPL and LPG biosynthetic pathways is discussed.

Reconstitution of the activities of the RecBCD holoenzyme of Escherichia coli from the purified subunits

The Escherichia coli RecBCD holoenzyme and the individual constituent subunits have been purified from overproducing strains. The purified RecBCD holoenzyme has a native molecular mass of approximately 330 kDa, indicative of a heterotrimer subunit assembly. The RecB, RecC, and RecD subunits can associate in vitro to give nuclease, helicase, ATPase, and Chi-specific endonuclease activities which are indistinguishable from those of the RecBCD holoenzyme. At concentrations at which the reconstituted RecB + C + D enzyme is very active, none of the individual RecB, RecC, or RecD subunits have readily detectable activities of the holoenzyme, except RecB protein which had previously been shown to exhibit DNA-dependent ATPase activity (Hickson, I. D., Robson, C. N., Atkinson, K. E., Hutton, L., and Emmerson, P. T. (1985) J. Biol. Chem. 260, 1224-1229). At higher concentrations and with shorter DNA substrates reconstituted RecBC protein exhibits low levels of helicase and exonuclease activity.

β-Oxidation enzymes in the mitochondria of Arum and oilseed rape

β-Oxidation enzymes were detected both in the mitochondria and microbodies of Arum maculatum L. spadices and Brassica napus L. seeds. It is apparent that the mitochondrial membrane barrier, which remains intact after sucrose-density-gradient centrifugation, prevents rapid access of acyl-GoA substrates to matrix βoxidation tes. Thus intact mitochondria showed little β-oxidation enzyme activity. Rupturing of the mitochondrial membrane allowed rapid access of acyl CoAs to matrix sites. Consequently, in ruptured mitochondria, high β-oxidation enzyme activities were measured.

Long-chain acyl CoA synthetase, carnitine and β-oxidation in the pea-seed mitochondrion

Mitochondria from pea (Pisum sativum L.) seeds were separated into two fractions, mitoplasts (intact inner membrane) and the outer-membrane fraction. The mitoplasts only oxidised palmitate in the presence of carnitine and added outermembrane fraction. Mitoplasts were able to oxidise palmitoylCoA in the presence of carnitine and added outer-membrane fraction had no effect on this oxidation. It was concluded that a long-chain acylCoA synthetase (EC 6.2.1.3) was located on the outer membrane and that the activity of this enzyme in assays was more than sufficient to account for any observed rate of O2 uptake during palmitate oxidation by pea mitochondria. The location of carnitine long-chain acyltransferase (carnitine palmitoyl transferase EC 2.3.1.21) would appear to be the mitoplast i.e. the inner mitochondrial membrane, and confirms the previous work at Newcastle.

A study of the reliability of reported premorbid adjustment in schizophrenic patients

A study was conducted to determine the interrater reliability and the inter-informant reliability of two rating scales commonly used with schizophrenic patients. Both scales were completed by two informants for each of 45 schizophrenics. The Levels of Functioning Scale, which measures current social functioning, gave consistent results both between raters and between informants. The Premorbid Asocial Adjustment Scale, which measures social functioning during childhood and adolescence, produced very high reliability between raters but very poor reliability between informants. This suggests that much of the data collected about premorbid adjustment of schizophrenic patients are not accurate and that attempts to correlate reported premorbid adjustment with biological measures may be invalid. Ways of increasing the reliability and validity of premorbid adjustment measures are discussed.