Exercise-associated generation of PPARγ ligands activates PPARγ signaling events and upregulates genes related to lipid metabolism

The aim of the present study was to test the hypotheses that exercise is associated with generation of peroxisome proliferator-activated receptor-γ (PPARγ) ligands in the plasma and that this may activate PPARγ signaling within circulating monocytes, thus providing a mechanism to underpin the exercise-induced antiatherogenic benefits observed in previous studies. A cohort of healthy individuals undertook an 8-wk exercise-training program; samples were obtained before (Pre) and after (Post) standardized submaximal exercise bouts (45 min of cycling at 70% of maximal O2 uptake, determined at baseline) at weeks 0, 4, and 8. Addition of plasma samples to PPARγ response element (PPRE)-luciferase reporter gene assays showed increased PPARγ activity following standardized exercise bouts (Post/Pre = 1.23 ± 0.10 at week 0, P < 0.05), suggesting that PPARγ ligands were generated during exercise. However, increases in PPARγ/PPRE-luciferase activity in response to the same standardized exercise bout were blunted during the training program (Post/Pre = 1.18 ± 0.14 and 1.10 ± 0.10 at weeks 4 and 8, respectively, P > 0.05 for both), suggesting that the relative intensity of the exercise may affect PPARγ ligand generation. In untrained individuals, specific transient increases in monocyte expression of PPARγ-regulated genes were observed within 1.5–3 h of exercise (1.7 ± 0.4, 2.6 ± 0.4, and 1.4 ± 0.1 fold for CD36, liver X receptor-α, and ATP-binding cassette subfamily A member 1, respectively, P < 0.05), with expression returning to basal levels within 24 h. In contrast, by the end of the exercise program, expression at the protein level of PPARγ target genes had undergone sustained increases that were not associated with an individual exercise bout (e.g., week 8 Pre/ week 0 Pre = 2.79 ± 0.61 for CD36, P < 0.05). Exercise is known to upregulate PPARγ-controlled genes to induce beneficial effects in skeletal muscle (e.g., mitochondrial biogenesis and aerobic respiration). We suggest that parallel exercise-induced benefits may occur in monocytes, as monocyte PPARγ activation has been linked to beneficial antidiabetic effects (e.g., exercise-induced upregulation of monocytic PPARγ-controlled genes is associated with reverse cholesterol transport and anti-inflammatory effects). Thus, exercise-triggered monocyte PPARγ activation may constitute an additional rationale for prescribing exercise to type 2 diabetes patients.

The epidemiology of red cell transfusion

BACKGROUND AND OBJECTIVES

Understanding of the clinical usage of red cells is limited despite its importance in transfusion practice improvement and planning for blood supply requirements. Previous studies have described red cell use based upon ICD and hospital discharge codes; however, such approaches are open to misclassification. This study addresses this limitation by undertaking an epidemiological analysis of red cell use using case note review.

MATERIALS AND METHODS

Patient, disease and contextual factors were extracted from the medical records of a randomly selected sample of hospital patients in Northern Ireland who received a red cell transfusion during 2005 (n=1474).

RESULTS

Transfused patients received a total of 3804 units (median of two units per transfusion episode). Most transfusions occurred in a medical setting (71%). Patients undergoing treatment for gastrointestinal conditions were responsible for the majority of the demand (29% of transfusion episodes; 34% of red cell units). The presence of bleeding and abnormal tests of coagulation were associated with receiving larger transfusions (≥ 3 units), while patients undergoing orthopaedic surgery and those with a haemoglobin level over 7 g/dl had the lowest risk of receiving ≥ 3 units in any one transfusion episode.

CONCLUSION

The majority of red cells are now prescribed in a medical setting. With an ageing population and increasing therapeutic interventions, the demand for blood is likely to increase despite efforts to reduce usage by eliminating inappropriate transfusions through education and behaviour change. The post-transfusion target (and therefore the number of units to transfuse) for any given clinical situation as well as guidance on a 'safe' transfusion threshold should be considered in future guidelines.

Development of a spatially resolving x-ray crystal spectrometer for measurement of ion-temperature (T(i)) and rotation-velocity (v) profiles in ITER

Imaging x-ray crystal spectrometer (XCS) arrays are being developed as a US-ITER activity for Doppler measurement of T(i) and v profiles of impurities (W, Kr, and Fe) with ∼7 cm (a/30) and 10-100 ms resolution in ITER. The imaging XCS, modeled after a prototype instrument on Alcator C-Mod, uses a spherically bent crystal and 2D x-ray detectors to achieve high spectral resolving power (E/dE>6000) horizontally and spatial imaging vertically. Two arrays will measure T(i) and both poloidal and toroidal rotation velocity profiles. The measurement of many spatial chords permits tomographic inversion for the inference of local parameters. The instrument design, predictions of performance, and results from C-Mod are presented.

The ITER core imaging x-ray spectrometer: x-ray calorimeter performance

We describe the anticipated performance of an x-ray microcalorimeter instrument on ITER. As part of the core imaging x-ray spectrometer, the instrument will augment the imaging crystal spectrometers by providing a survey of the concentration of heavy ion plasma impurities in the core and possibly ion temperature values from the emission lines of different elemental ions located at various radial positions.

Low-intensity exercise enhances expression of markers of alternative activation in circulating leukocytes: roles of PPARγ and Th2 cytokines

OBJECTIVE

Pharmacological activation of the nuclear receptor PPARγ is linked to numerous beneficial effects in the contexts of inflammation, lipid homeostasis, Type-2 Diabetes (T2D) and atherosclerosis. These beneficial effects include priming of circulating monocytes for differentiation towards an 'alternative' anti-inflammatory M2 macrophage phenotype. As we have recently shown that participation in low-intensity exercise increases PPARγ expression and activity in leukocytes from previously sedentary individuals, we aimed to elucidate whether low-intensity exercise elicited a pattern of gene expression similar to that reported for M2 monocyte-macrophage differentiation.

METHODS

17 sedentary individuals undertook an 8-week low-intensity exercise programme (walking 10,000steps/day, three times/week). Changes in expression of PPARs and the PPARγ co-activators PGC-1α and PGC-1β; Th2 (IL-4; IL-10) and Th1 (IL-6) cytokines; and markers for the M2 (AMAC1, CD14, MR, IL-4) and the 'classical' pro-inflammatory M1 (MCP-1, TNFα, IL-6) phenotypes, were determined using RT-PCR (to assess leukocyte mRNA expression) and ELISA (to assess plasma cytokine levels).

RESULTS

Exercise was associated with upregulation of M2 markers, PGC-1α and PGC-1β, and with downregulation of M1 markers. Moreover, plasma levels of Th2 cytokines increased after exercise, while those of Th1 cytokines decreased. However, other PPARs (PPARα; PPARβ/δ) did not undergo marked exercise-induced activation or upregulation. Thus, participation in low-intensity exercise may prime monocytes for differentiation towards an M2 macrophage phenotype via PPARγ/PGC-1α/β.

CONCLUSION

Given the similarities between these effects and pharmacologically induced M2 polarisation, we propose that exercise-induced PPARγ/PGC-1α/β-mediated M2 polarisation may constitute a novel anti-inflammatory benefit of low-intensity exercise.

Dopaminergic challenges in social anxiety disorder: evidence for dopamine D3 desensitisation following successful treatment with serotonergic antidepressants

Serotonergic antidepressants (SSRIs) are first-line treatments for social anxiety disorder [SAnD], though there is evidence of dopaminergic system dysfunction. Twenty subjects with DSM-IV SAnD, untreated (n = 10) and SSRI-remitted DSM-IV SAnD (n = 10), were administered a single dose of 1) a dopamine agonist (pramipexole 0.5 mg) and 2) a dopamine antagonist (sulpiride 400 mg), followed by anxiogenic challenges (verbal tasks and autobiographical scripts) in a double-blind crossover design, the two test days being one week apart. Anxiety symptoms were measured by self-reported changes in Visual Analogue Scales, specific SAnD scales and anxiety questionnaires. Plasma levels of prolactin were obtained. Untreated SAnD subjects experienced significant increases in anxiety symptoms following behavioural challenges after either sulpiride or pramipexole. Following remission with SSRIs, the socially anxiogenic effect of behavioural provocation was significantly attenuated under pramipexole, whereas under sulpiride effects remained significantly elevated. There appears to be instability of the dopamine system under behavioural stress in social anxiety subjects that is only partly rectified by successful treatment with an SSRI, which may induce a desensitisation of postsynaptic dopamine D(3) receptors.

Nitrite directly vasodilates hypoxic vasculature via nitric oxide-dependent and -independent pathways

BACKGROUND AND PURPOSE

It is postulated that nitrite requires reduction to nitric oxide in order to exert its relaxant effect upon isolated hypoxic vessels. Herein, we evaluate the relative contribution of nitric oxide and characterize the downstream mechanisms of nitrite-induced vasorelaxation.

EXPERIMENTAL APPROACH

Aortic rings were treated with pharmacological agents and exposed to hypoxia (<1% O(2)). Following pre-constriction, nitrite (10 microM final) was added to appropriate baths; isometric tension was recorded throughout.

KEY RESULTS

Nitrite (under hypoxic conditions at physiological pH) is capable of exerting physiological effects that cannot be completely inhibited by the inhibitor of soluble guanylate cyclase (sGC), 1H [1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one or a nitric oxide scavenger (carboxy-2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide). Simultaneous blockade of both sGC and cyclooxygenase (COX) completely inhibited the response to nitrite. With regard to the nitric oxide-dependent component, we confirm that aldehyde oxidase, but not xanthine oxidase or endothelial nitric oxide synthase, was important for the actions of nitrite in our model.

CONCLUSIONS AND IMPLICATIONS

Nitric oxide generated from nitrite is not exclusively responsible for the physiological actions observed in isolated hypoxic vessels. Nitrite operates via different pathways dependent on the presence or absence of endothelium to produce vasorelaxation. In intact vessels, both sGC and COX enzymes appear to be important. Irrespective of this difference in relaxation mechanism, nitrite is capable of producing the same maximum relaxation, regardless of the presence of endothelium. Having investigated possible nitrite reduction sites, we confirm that aldehyde oxidase is important for the actions of nitrite.

Optimization of the optical design of the ITER MSE diagnostic

The motional Stark effect (MSE) diagnostic will be essential for the study of advanced scenarios on ITER and its design is currently underway with initial emphasis on the optical design. Optical performance, as measured by photon throughput and minimization of polarization aberrations, will be critical to the success of the diagnostic. Consequently, the initial design work has been focused heavily on this area. In order meet the ITER MSE diagnostic design requirements, two approaches for the measurement are under consideration. The first is based on standard polarimeter techniques to measure the polarization of the emitted light, whereas the second measures the Stark splitting from which absolute value(B) can be inferred, where absolute value(B) is the magnitude of the total magnetic field. The base line design of the optical system is centered on the first approach. Emphasis in this case is placed on minimizing the polarization aberrations of the optical relay system. Motivation for the second method results from concern that the optical properties of the plasma-facing mirror, particularly its diattenuation and retardance, will degrade with plasma exposure. The second approach, while less sensitive to aberrations induced by plasma exposure effects, requires greater optical throughput in order to measure the complete Stark spectrum. We have developed an optimized optical design applicable to both measurement techniques. A summary of the design is presented and design issues are discussed.

The presenting complaints of low income adults for emergency dental care: an analysis of 35,000 episodes in Victoria, Australia

OBJECTIVE

This study examined the mix of presenting problems faced by a large diverse dental service treating low-income Australian adults and provides a basis for communities to understand and manage demand for dental services.

DESIGN

A retrospective analysis in a state-wide multi-centre dental health service. Data for all patients (in all public adult dental clinics in the state of Victoria during May-Aug 2005) who used the emergency services in a 12 week period were recorded and analysed. A triage question tree was developed and embedded into a neural network based computer triage tool.

RESULTS

Approximately 52% of low income adults presenting for emergency treatment required treatment on the day of triage. The main problem was with natural teeth (89.6%). Of those with natural teeth problems, 41.3% had pain disturbing their sleep patterns and 14.7% had experienced a swelling. Metropolitan patients accessed the services 2.3 times more than rural patients.

CONCLUSION

These data clearly highlight that there is significant opportunity to reduce nearly 48% of on-day demand for emergency dental care through the application of appropriately clinical based triage.

Robust, routine haematology reference ranges for healthy adults

Accurate, reliable laboratory reference ranges are essential for effective clinical evaluation and monitoring. We present robust reference ranges established for haematology, coagulation and haematinic parameters using the Sysmex XE 2100, CA 1500 and Beckman-Coulter Access analysers. Blood samples were taken from 250 healthy laboratory personnel and routine haematology, coagulation and haematinic parameter analysis performed. Our data represent findings from an extensive study to establish reference ranges in healthy adults.

What would encourage blood donation in Ireland?

BACKGROUND

Recent changes have resulted in the loss of 4% of the donor panel in the Republic of Ireland and 3% in Northern Ireland. In order to increase the number of donors in these two regions, it is important that transfusion service providers explore and understand the reasons, which prevent individuals from donating. The aim of this study was to explore these issues particularly in non-donors and those who had lapsed.

METHODS

This 7-month all-Ireland study was conducted by computer-assisted telephone interview. Data collected included sociodemographic history, donation status, as well as barriers/deterrents to donation.

RESULTS

There were 4166 completed questionnaires (44% donors; 56% non-donors). Of the donors, 13% had donated blood within the last 2 years. Current donors cited 'awareness of patients needs' (88%), 'trust in the blood transfusion service' (70%), and 'an advertising campaign' (70%) as reasons encouraging them to donate blood. Lapsed donors and non-donors cited 'more frequent mobile clinics/sessions' (30% lapsed donors; 53% non-donors), 'if I was asked' (28% lapsed donors; 53% non-donors), and 'more flexible opening hours' (23% lapsed donors; 44% non-donors) as reasons that would encourage them to donate. The main reasons cited by non-donors for never having donated included 'medical reasons' (41% Republic of Ireland; 43% Northern Ireland), 'lack of information' (20% Republic of Ireland; 22% Northern Ireland), 'fear of needles' (15% Republic of Ireland; 17% Northern Ireland), and 'time constraints' (12% Republic of Ireland; 13% Northern Ireland). Among the non-donor group, 10% (Republic of Ireland) and 6% (Northern Ireland) claimed that they are not permitted to donate.

CONCLUSION

Replacing regular donors is a major challenge for the transfusion service providers. This study shows that by facilitating the general public by introducing more mobile clinics/sessions, more flexible opening hours and having a better level of knowledge in the community about blood donation may encourage lapsed donors and new donors to become regular donors.

Acute effects of caffeine and tobacco on arterial function and wave travel

BACKGROUND

Caffeine and tobacco consumption are risk factors for heart failure, but their effects remain controversial. It has been hypothesized that they cause alterations in arterial stiffness and arterial wave travel which may increase ventricular loading. In this study the authors examined the influence of these widely used stimulants on wave intensity and arterial stiffness parameters using carotid wave intensity analysis.

MATERIALS AND METHODS

A new Doppler-based ultrasound method was used to measure the acute effects of caffeine and tobacco on wave intensity in the right common carotid artery. The measurements enabled changes in arterial stiffness parameters to be recorded.

RESULTS

In 17 subjects compared with 10 controls, caffeine increased blood pressure, early systolic wave intensity and wave speed, but late-systolic wave intensity and mid-systolic reflections were unchanged. In 11 smokers studied before and after smoking one cigarette, blood pressure and arterial stiffness increased but wave intensity was unchanged. No changes were observed in the controls.

CONCLUSIONS

Increased wave intensity during ejection after caffeine suggested sympathomimetic effects on the left ventricular function. Increased wave speed in the common carotid artery implied augmented central loading after caffeine, but the absence of measurable changes in local arterial stiffness in the carotid artery suggested more complex and regional effects. Cigarette smoking acutely increased local arterial stiffness in the common carotid artery. These changes can be detected using wave intensity analysis.

Hypothermia pediatric head injury trial: the value of a pretrial clinical evaluation phase

BACKGROUND

The utility of a pretrial clinical evaluation or run-in phase prior to conducting trials of complex interventions such as hypothermia therapy following severe traumatic brain injury in children and adolescents has not been established.

METHODS

The primary objective of this study was to prospectively evaluate the ability of investigators to adhere to the clinical protocols of care including the cooling and rewarming procedures as well as management guidelines in patients with severe traumatic brain injury (Glasgow Coma Scale<or=8) treated with 24 h of hypothermia therapy. A secondary objective was to evaluate the ability of study research assistants to complete the study case report form using a procedures manual. The study was conducted at 18 sites in Canada, the United Kingdom and France prior to proceeding to a randomized controlled trial (RCT). After 2 patients were enrolled at each center, an independent clinical evaluation committee examined the process of care and the completeness of data collection. Centers were permitted to enroll patients in the RCT once they met pre-established adherence criteria.

RESULTS

Seventeen of the 18 centers completed the pretrial clinical evaluation phase demonstrating compliance with study procedures and proceeded to an RCT of hypothermia therapy. One center enrolled only 1 patient in the pretrial clinical evaluation phase due to small numbers of patients with traumatic brain injury, and therefore, did not proceed to the RCT. Three centers were required to enroll more than 2 patients in the pretrial clinical evaluation phase prior to proceeding to the RCT because of problems with adherence to the clinical protocols at two centers and the training of new study personnel at another center. Of the 39 patients enrolled during the pretrial clinical evaluation phase, 8 (20.5%) died and 22 (62.9%) had a good outcome defined as normal, mild or moderate disability assessed using the Pediatric Cerebral Performance Category score at 6 months following injury.

DISCUSSION

The pretrial clinical evaluation phase was useful to ensure compliance with complex hypothermia therapy and consensus-based clinical management guidelines of care successfully implemented across 17 of 18 centers. This study maneuver allowed us to complete a subsequent RCT in 225 children following severe traumatic brain injury.

Direct characterization of Blastocystis from faeces by PCR and evidence of zoonotic potential

In vitro propagation followed by PCR, and a PCR-based method capable of the direct detection of Blastocystis in faeces were utilized to detect Blastocystis from various hosts in Australia, including primates and their handlers from the Perth Zoo. In addition, Blastocystis isolates from dogs and humans living in a localized endemic community in Thailand were also characterized genetically. PCR-based detection directly from faeces was shown to be more sensitive compared with in vitro culture for the detection of Blastocystis. Moreover, phylogenetic analysis of Blastocystis isolates amplified utilizing in vitro techniques prior to PCR revealed that this method favoured the preferential amplification of Blastocystis subtype 5 over subtype 1. This study is the first to provide molecular-based evidence supporting the zoonotic potential of Blastocystis in dogs, possums and primates in a natural setting.

Mice deficient in galectin-1 exhibit attenuated physiological responses to chronic hypoxia-induced pulmonary hypertension

Pulmonary hypertension (PH) is characterized by sustained vasoconstriction, with subsequent extracellular matrix (ECM) production and smooth muscle cell (SMC) proliferation. Changes in the ECM can modulate vasoreactivity and SMC contraction. Galectin-1 (Gal-1) is a hypoxia-inducible beta-galactoside-binding lectin produced by vascular, interstitial, epithelial, and immune cells. Gal-1 regulates SMC differentiation, proliferation, and apoptosis via interactions with the ECM, as well as immune system function, and, therefore, likely plays a role in the pathogenesis of PH. We investigated the effects of Gal-1 during hypoxic PH by quantifying 1) Gal-1 expression in response to hypoxia in vitro and in vivo and 2) the effect of Gal-1 gene deletion on the magnitude of the PH response to chronic hypoxia in vivo. By constructing and screening a subtractive library, we found that acute hypoxia increases expression of Gal-1 mRNA in isolated pulmonary mesenchymal cells. In wild-type (WT) mice, Gal-1 immunoreactivity increased after 6 wk of hypoxia. Increased expression of Gal-1 protein was confirmed by quantitative Western analysis. Gal-1 knockout (Gal-1(-/-)) mice showed a decreased PH response, as measured by right ventricular pressure and the ratio of right ventricular to left ventricular + septum wet weight compared with their WT counterparts. However, the number and degree of muscularized vessels increased similarly in WT and Gal-1(-/-) mice. In response to chronic hypoxia, the decrease in factor 8-positive microvessel density was similar in both groups. Vasoreactivity of WT and Gal-1(-/-) mice was tested in vivo and with use of isolated perfused lungs exposed to acute hypoxia. Acute hypoxia caused a significant increase in RV pressure in wild-type and Gal-1(-/-) mice; however, the response of the Gal-1(-/-) mice was greater. These results suggest that Gal-1 influences the contractile response to hypoxia and subsequent remodeling during hypoxia-induced PH, which influences disease progression.

Impaired vasoreactivity in bodybuilders using androgenic anabolic steroids

BACKGROUND

Anabolic androgenic steroids are used by some bodybuilders to enhance performance. While the cardiovascular implications of supraphysiological androgen levels requires further clarification, use is associated with sudden death, left ventricular hypertrophy, thrombo-embolism and cerebro-vascular events.

MATERIALS AND METHODS

To further understand the effect of androgenic anabolic steroid abuse on vascular function, this study assessed vascular stiffness (pulse-wave analysis) and cardiovascular risk factors in 28 male, bodybuilding subjects, of whom ten were actively receiving anabolic agents (group A; 26.4 +/- 7.2 years) and eight had undergone a 3-month "wash-out" period (group B; 32.1 +/- 7.1 years). The remaining ten bodybuilding subjects (group C; 24.4 +/- 4.4 years) denied any past use of anabolic steroids or other performance enhancing drugs. Comparisons were made with ten sedentary male controls (group D, 29.3 +/- 4.7 years).

RESULTS

Endothelial independent dilatation in response to glycerol trinitrate was significantly impaired in the group currently using anabolic steroids (group A) compared with the other three groups [A (5.63 +/- 3.24%) versus; B (11.10 +/- 4.91%), C (17.88 +/- 9.2%) and D (14.46 +/- 3.9%), P < 0.0005, respectively], whereas no significant differences in endothelial-dependent dilatation were detected between the groups [A (5.0 +/- 3.0%), B (7.4 +/- 3.4%), C (9.6 +/- 4.5%) and D (8.2 +/- 3.3%), P < 0.059, respectively].

CONCLUSIONS

Previous studies described a decline in vascular reactivity occurring in bodybuilding subjects which is independent of anabolic steroid use and may result from smooth muscle hypertrophy with increased vascular stiffness. This study revealed impaired vascular reactivity associated with anabolic agents and that improvement in vascular function may occur following their discontinuation.

Prolonged deterioration of endothelial dysfunction in response to postprandial lipaemia is attenuated by vitamin C in Type 2 diabetes

BACKGROUND

Endothelial dysfunction (ED) has been described in Type 2 diabetes (T2DM). We have described previously a diminution of flow-mediated arterial dilatation and, by implication, further ED in T2DM in response to postprandial lipaemia (PPL) at 4 h. This is possibly mediated by oxidative stress/alteration of the nitric oxide (NO) pathway. T2DM subjects tend to exhibit both exaggerated and prolonged PPL. We therefore studied the relationship of PPL to the duration of ED in T2DM subjects and oxidative stress with or without the antioxidant, vitamin C.

METHODS

Twenty subjects with T2DM with moderate glycaemic control (mean HbA1c 8.4%) were studied. After an overnight fast, all subjects consumed a standard fat meal. Endothelial function (EF), lipid profiles, and venous free radicals were measured in the fasting, peak lipaemic phase (4 h) and postprandially to 8 h. The study was repeated in a double-blinded manner with placebo, vitamin C (1 g) therapy for 2 days prior to re-testing and with the fat meal. Oxidative stress was assessed by lipid-derived free radicals in plasma, ex vivo by electron paramagnetic resonance spectroscopy (EPR) and by markers of lipid peroxidation (TBARS). Endothelial function was assessed by flow-mediated vasodilatation (FMD) of the brachial artery.

RESULTS

There was a significant decrease in endothelial function in response to PPL from baseline (B) 1.3 +/- 1.3% to 4 h 0.22 +/- 1.1% (P < 0.05) and 8 h 0.7 +/- 0.9% (P < 0.05) (mean +/- sem). The endothelial dysfunction seen was attenuated at each time point with vitamin C. Baseline EF with vitamin C changed from (fasting) 3.8 +/- 0.9-2.8 +/- 0.8 (at 4 h) and 2.9 +/- 1.3 (at 8 h) in response to PPL. Vitamin C attenuated postprandial (PP) oxidative stress significantly only at the 4-h time point [301.1 +/- 118 (B) to 224.7 +/- 72 P < 0.05] and not at 8 h 301.1 +/- 118 (B) to 260 +/- 183 (P = NS). There were no changes with placebo treatment in any variable. PPL was associated with a PP rise in TG levels (in mmol/l) from (B) 1.8 +/- 1 to 2.7 +/- 1 at 4 h and 1.95 +/- 1.2 at 8 h (P = 0.0002 and 0.33, respectively).

CONCLUSION

PPL is associated with prolonged endothelial dysfunction for at least 8 h after a fatty meal. Vitamin C treatment improves endothelial dysfunction at all time points and attenuates PPL-induced oxidative stress. This highlights the importance of low-fat meals in T2DM and suggests a role for vitamin C therapy to improve endothelial function during meal ingestion.

Smaller inner ear sensory epithelia in Neurog 1 null mice are related to earlier hair cell cycle exit

We investigated whether co-expression of Neurog 1 and Atoh 1 in common neurosensory precursors could explain the loss of hair cells in Neurog 1 null mice. Analysis of terminal mitosis, using BrdU, supports previous findings regarding timing of exit from cell cycle. Specifically, we show that cell cycle exit occurs in spiral sensory neurons in a base-to-apex progression followed by cell cycle exit of hair cells in the organ of Corti in an apex-to-base progression, with some overlap of cell cycle exit in the apex for both hair cells and spiral sensory neurons. Hair cells in Neurog 1 null mice show cell cycle exit in an apex-to-base progression about 1-2 days earlier. Atoh 1 is expressed in an apex-to-base progression rather then a base-to-apex progression as in wildtype littermates. We tested the possible expression of Atoh1 in neurosensory precursors using two Atoh 1-Cre lines. We show Atoh 1-Cre mediated beta-galactosidase expression in delaminating sensory neuron precursors as well as undifferentiated epithelial cells at E11 and E12.5. PCR analysis shows expression of Atoh 1 in the otocyst as early as E10.5, prior to any histology-based detection techniques. Combined, these data suggest that low levels of Atoh 1 exist much earlier in precursors of hair cells and sensory neurons, possibly including neurosensory precursors. Analysis of Atoh 1-Cre expression in E18.5 embryos and P31 mice reveal beta-galactosidase stain in all hair cells but also in vestibular and cochlear sensory neurons and some supporting cells. A similar expression of Atoh 1-LacZ exists in postnatal and adult vestibular and cochlear sensory neurons, and Atoh 1 expression in vestibular sensory neurons is confirmed with RT-PCR. We propose that the absence of NEUROG 1 protein leads to loss of sensory neuron formation through a phenotypic switch of cycling neurosensory precursors from sensory neuron to hair cell fate. Neurog 1 null mice show a truncation of clonal expansion of hair cell precursors through temporally altered terminal mitosis, thereby resulting in smaller sensory epithelia.

Detection of HCV and HIV-1 antibody negative infections in Scottish and Northern Ireland blood donations by nucleic acid amplification testing

BACKGROUND AND OBJECTIVES

To reduce the risk of transfusion-transmissible viruses entering the blood supply, the nucleic acid amplification testing (NAT) was implemented to screen Scottish and Northern Irish blood donations in minipools. After 5 years of NAT for hepatitis C virus (HCV) and 2 years for human immunodeficiency virus-1 (HIV-1), the yield of serologically negative, nucleic acid positive 'window donations' and cost-benefit of NAT is under review.

MATERIALS AND METHODS

When the Scottish National Blood Transfusion Service (SNBTS) implemented NAT in 1999, a fully automated 'black box' system was not available. Therefore, an 'in-house' assimilated NAT assay was developed, validated and implemented. The system is flexible and allows testing for additional viral markers to be introduced with relative ease.

RESULTS

The HCV and HIV NAT assays have 95% detection levels of 7.25 IU/ml and 39.8 IU/ml, respectively, as determined by probit analysis. One HCV (1 in 1.9 million) and one HIV (1 in 0.77 million) window donation have been detected in 5 and 2 years, respectively, of NAT.

CONCLUSION

The SNBTS NAT assays are robust and have performed consistently over the last 5 years. The design of the in-house system allowed HIV NAT to be added in 2003 at a relatively small additional cost per sample, although for both assays, the royalty fee far exceeds the cost of the test itself. Clearly NAT has a benefit in improving the safety of the blood supply although the risks of transfusion-transmitted viral infections, as reported in the Serious Hazards of Transfusion (SHOT) report, are extremely low. Also, in UK the yield of HCV antibody negative, NAT positive donations is far lower than predicted although the early detection of an HIV window period donation and the increase of HIV in the blood donor and general populations may provide a stronger case for HIV NAT. SUMMARY SENTENCE: The yield of HCV and HIV NAT in UK is significantly less than that anticipated from statistical models.

The transcriptional landscape of the mammalian genome

This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.

Intérêt de la télépathologie dans le diagnostic rapide des spécimens neurochirurgicaux

To determine whether still digital images of neurosurgical specimens sent by e-mail are an effective and safe way of obtaining an emergency pathological diagnosis, representative images from 48 neurosurgical smear specimens were digitized, compressed and sent by electronic mail to our consultant neuropathologist with relevant clinical and radiological information. The time to select, digitize, compress and send the images for each case was recorded. Comparison was made between diagnosis made from digital images (DI) and historical smear (HS) using the original permanent section (PS) diagnosis as the gold standard. A diagnosis of normal vs. abnormal, neoplastic vs. non-neoplastic, primary vs. secondary and tumor grade was made in each case. The mean time for selection and digitalization of each case was 9.51 minutes. The number of correct pathological diagnosis was 41/48 using DI and 48/48 using HS, giving an accuracy rate of 85.4% and 100% respectively. DI was 100% sensitive in recognizing neoplastic tissue but only 98% specific. Most inaccuracies were in grading and caused by problems with field selection and familiarity with the technique. We conclude that static digital images are reliable and safe method of interpreting tissue during neurosurgical procedures. This corresponds with the findings of previous studies.

Total Synthesis of Cytotoxic Anhydrophytosphingosine Pachastrissamine (Jaspine B)

Starting from L-serine, a stereoselective synthesis of pachastrissamine, a structurally novel anhydrosphingosine derivative, is reported in this Letter. [structure: see text]

Prevalence and clonality of Burkholderia cepacia complex genomovars in UK patients with cystic fibrosis referred for lung transplantation

BACKGROUND

It has previously been reported that patients infected with Burkholderia cenocepacia (genomovar III) before lung transplantation have a poorer outcome than those with other B. cepacia complex infections.

METHODS

An extensive study was conducted to determine the prevalence and clonality of B. cepacia complex genomovars isolated from patients referred for transplant assessment between 1989 to the present and, where appropriate, whether strain type was related to transplant outcome.

RESULTS

Isolates from 29 patients were identified as B. cepacia complex organisms by molecular analysis. Thirteen patients (45%) were infected with the highly transmissible ET-12 strain of B. cenocepacia recA lineage III-A, while all remaining patients were infected with genetically unique B. cenocepacia, B. multivorans, and B. vietnamiensis strains. All previously reported deaths following transplantation were associated with ET-12 infection.

CONCLUSIONS

The ET-12 strain is the predominant cause of B. cenocepacia infections in patients with cystic fibrosis referred to our pulmonary transplant centre and is associated with poor transplant outcomes using standard treatment regimens.

False positive Kleihauer tests and unnecessary administration of anti-D immunoglobulin

This obstetric case shows two false negative Kleihauer tests and two persistently positive Kleihauer tests leading to unnecessary administration of anti-D immunoglobulin. A diagnosis of hereditary persistence foetal haemoglobin (HPFH) was only confirmed by access to flow cytometry making use of both anti-HbF and anti-D labels. The case highlights the importance of a high index of clinical suspicion for HPFH and the importance of access to flow cytometry estimation of minor RhD red cell populations postnatally in RhD-negative mothers.

Amygdala volumetry in "imaging-negative" temporal lobe epilepsy

OBJECTIVE

Although amygdala abnormalities are sometimes suspected in "imaging-negative" patients with video EEG confirmed unilateral focal epilepsy suggestive of temporal lobe epilepsy (TLE), amygdala asymmetry is difficult to assess visually. This study examined a group of "imaging-negative" TLE patients, estimating amygdala volumes, to determine whether cryptic amygdala lesions might be detected.

METHODS

Review of video EEG monitoring data yielded 11 patients with EEG lateralised TLE and normal structural imaging. Amygdala volumes were estimated in this group, in 77 patients with pathologically verified hippocampal sclerosis (HS), and in 77 controls.

RESULTS

Seven of 11 "imaging-negative" cases had both significant amygdala asymmetry and amygdala enlargement, concordant with seizure lateralisation. Although significant amygdala asymmetry occurred in 35 of 77 HS patients, it was never attributable to an abnormally large ipsilateral amygdala. Compared with patients with HS, patients with amygdala enlargement were less likely to have suffered secondarily generalised seizures (p<0.05), and had an older age of seizure onset (p<0.01).

CONCLUSION

Abnormal amygdala enlargement is reported in seven cases of "imaging-negative" TLE. Such abnormalities are not observed in patients with HS. It is postulated that amygdala enlargement may be attributable to a developmental abnormality or low grade tumour. It is suggested that amygdala volumetry is indicated in the investigation and diagnosis of "imaging-negative" TLE.

Gas-phase detection of trinitrotoluene utilizing a solid-phase antibody immobilized on a gold film by means of surface plasmon resonance spectroscopy

A multilayered biosensor was constructed and found to detect trinitrotoluene (TNT) in ppb concentrations in air both prior to and after detonation of TNT without use of a liquid phosphate buffered saline (PBS) superstrate. The biosensor surface was fabricated from a monoclonal antibody for TNT covalently bound to an 11,11'-dithio-bis(succinimidoylundecanoate) (DSU) self-assembled monolayer immobilized on a thin gold film bonded to a BK7 glass slide. The binding between the immobilized antibody and TNT antigen was detected using surface plasmon resonance spectroscopy (SPRS). Biosensor specificity for TNT was demonstrated with chemical homologues as well as against an unrelated explosive, RDX.

Evolution of Parasitism in Insect-transmitted Plant Nematodes

Nematode-insect associations have evolved many times in the phylum Nematoda, but these lineages involve plant parasitism only in the Secernentean orders Aphelenchida and Tylenchida. In the Aphelenchida (Aphelenchoidoidea), Bursaphelenchus xylophilus (Pine wood nematode), B. cocophilus (Red ring or Coconut palm nematode) (Parasitaphelenchidae), and the many potential host-specific species of Schistonchus (fig nematodes) (Aphelenchoididae) nematode-insect interactions probably evolved independently from dauer-forming, mycophagous ancestors that were phoretically transmitted to breeding sites of their insect hosts in plants. Mycophagy probably gave rise to facultative or obligate plant-parasitism because of opportunities due to insect host switches or peculiarities in host behavior. In the Tylenchida, there is one significant radiation of insect-associated plant parasites involving Fergusobia nematodes (Fergusobiinae: Neotylenchidae) and Fergusonina (Fergusoninidae) flies as mutualists that gall myrtaceous plant buds or leaves. These dicyclic nematodes have different phases that are parasitic in either the insect or the plant hosts. The evolutionary origin of this association is unclear.

Distribution and habitat features associated with remnant populations of New England cottontails in Maine

We investigated the distribution and habitat associations of New England cottontails (Sylvilagus transitionalis; NEC) at the northern edge of their historic range (state of Maine) during the winters of 1999–2000 and 2000–2001. We compared features of regions ([Formula: see text]100 km2), landscapes (multiple home ranges of NEC within 1 km of suitable habitat), and patches (usually <0.1 km2) among sites that were occupied by NEC, occupied by a potential competitor (snowshoe hares, Lepus americanus), or vacant. The current range of NEC in Maine is approximately 1600 km2 versus a recent historic range of 9400 km2 (83% decline). Loss of early-successional forests may explain the decline in abundance but does not explain the pattern of range contraction. Patches occupied by NEC were larger, had a greater density of understory vegetation, and were more frequently associated with idle agricultural lands than vacant patches. Habitats occupied by snowshoe hares were characterized by a greater proportion of forest and a lower density of roads in the surrounding landscape, were more often associated with recent clearcuts, and had a lower density of understory vegetation than sites occupied by NEC. Based on current land-use patterns, remaining populations of NEC in Maine are vulnerable to extirpation.

Effects of insulin lispro and chronic vitamin C therapy on postprandial lipaemia, oxidative stress and endothelial function in patients with type 2 diabetes mellitus

BACKGROUND

Insulin therapy may influence cardiovascular disease (CVD) and lipid metabolism in type 2 diabetes (T2D). Exaggerated postprandial lipaemia (PPL) is a feature of diabetic dyslipidaemia affecting CVD via enhanced oxidative stress (OS) and endothelial dysfunction. We assessed endothelial function and OS during PPL following insulin and vitamin C. Twenty (17 M) T2D patients were studied (mean Hba1c 8.4%) at baseline, following 6 weeks of insulin lispro (0.2 Iu kg-1) and vitamin C 1-g daily. Eight-h lipid and glucose profiles were measured following a fatty meal. Endothelial function (flow-mediated vasodilatation: FMD) and OS were measured at fasting, 4 h and 8 h.

MATERIALS AND METHODS

Glucose, body mass index, and total and LDL cholesterol remained unchanged. FMD improved. Placebo group: fasting, 1.1 +/- 1.2 to 4.2 +/- 1.1% (P < 0.001); 4-h, 0.3 +/- 1.2 to 3.1 +/- 0.9% (P < 0.01); 8-h, 0.7 +/- 1.1 to 3.76 +/- 1.1% (P < 0.001). Vitamin C group: fasting, 0.9 +/- 1.1 to 6.1 +/- 1.3% (P < 0.001); 4-h, 0.7 +/- 1.5 to 4.9 +/- 2.1% (P < 0.001); 8-h, 0.8 +/- 0.9 to 5.8 +/- 0.6% (P < 0.01). Post-prandial lipaemia was attenuated: TG area-under-curve (mmol L-1 8 h-1), 52.6 +/- 11 to 39.1 +/- 12.5 (placebo group), P < 0.02; and 56.9 +/- 8 to 40.1 +/- 10.3 (vitamin C group), P < 0.02. Oxidative stress was reduced, with greater changes in the vitamin C group.

CONCLUSION

Insulin may thus exert vascular benefits in T2D, by modifying fasting and postprandial lipid metabolism resulting in reduced OS and improved EF. Vitamin C therapy may augment the vascular benefits of insulin in T2D through additional effects on OS and EF.