P5385Development and preclinical testing of upscaled engineered heart tissue for use in translational studies

Introduction

The lack of efficacy of stem cell therapy for the treatment of heart failure may be related to the poor retention rates offered by existing delivery methods (intra-coronary/ intramyocardial). Tissue engineering strategies improve cell retention in small animal models but data regarding engineered heart tissue (EHT) patches large enough for human studies are lacking.

Purpose

To upscale EHT to a clinically relevant size and mature the patch in-vitro. Once matured to undergo preclinical testing in a rabbit model of myocardial infarction.

Methods

We developed an upscaled EHT patch (3cm x 2cm x 1.5mm) able to contain up to 50 million human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CM; Fig A/B). Myocardial infarction model was performed by permanent ligation.

Results

The patches began to beat spontaneously within 3 days of fabrication and after 28 days of dynamic culture (Late EHTs) showed the development of several mature characteristics when compared to early patches (<14 days from fabrication). For example, late EHTs contained hiPSC-CMs which were more aligned (hiPSC-CM accumulative angle change: early 2702±778 degrees [n=4] vs late 922±186 [n=5], p=0.042); showed better contraction kinetics (early peak contraction amplitude 87.9±5.8a.u. versus late 952±304a.u.; p<0.001) and faster calcium transients (time to peak: early 200.8±8.8ms [n=5] vs late 147.7±10.2ms [n=6], p=0.004; time to 75% decay: early 274±9.7ms vs late 219.9±2.7ms, p=0.0003).

We then tested the EHT patch in-vivo using a rabbit model (Fig C). Patches were applied to normal (n=5) or infarcted hearts (n=8). Sham operations used non-cellular fibrin patches (n=5). The mean fraction of troponin positive cells in the graft was 27.8±10.3% at 25.2±1.7 days relative to day 0 [n=5] and KU80 (human specific marker) staining confirmed that this was of human origin. CD31 (Fig D) and KU80 staining revealed that the grafts were well vascularized and that the vasculature was not human in origin (therefore were originating from the host). Ex-vivo optical mapping revealed evidence of electrical coupling between the graft and host at 2 weeks and preliminary experiments indicated that the patch improved left ventricular function when grafted onto infarcted hearts. Telemetry recordings in vivo and arrhythmia provocation protocols (ex vivo) indicated that the patch was not proarrhythmic.

Figure 1. A/B) EHT Images; C) 20x troponin T (brown) of rabbit myocardium/EHT (2 weeks after grafting), blue counterstain = haematoxylin, red lines = EHT borders; D) 63x CD31 staining (brown) rabbit/EHT border zone (2 weeks after grafting), blue stain = haematoxylin, red lines = graft/host border zones.

Conclusion

We successfully upscaled hiPSC-CM derived EHT to a clinically relevant size and demonstrated feasibility and integration using a rabbit model of myocardial infarction. Tissue engineering strategies may be the preferred modality of cell delivery for future cardiac regenerative medicine studies.

Does the frequency of routine follow-up after curative treatment for head-and-neck cancer affect survival?

Background

Routine follow-up is a cornerstone of oncology practice, but evidence to support most aspects of follow-up is lacking. Our objective was to investigate the relationship between frequency of routine follow-up and survival.

Methods

This population-based study used electronic health care data relating to 5310 patients from Ontario diagnosed with squamous-cell head-and-neck cancer during 2007-2012. Treatments included surgery (24.6%), radiotherapy with or without chemotherapy (52.4%), and combined surgery and radiotherapy (23%). We determined the oncologist who was following each patient after treatment; calculated the average follow-up visits to the oncologist during the subsequent 2.5 years for all patients who were doing well; and used Kaplan-Meier and multiple variable regression analysis to compare, by treatment, overall survival for patients in the high, typical, and low follow-up oncologist groups.

Results

Many oncologists saw patients 40%-80% more often than other oncologists did. No relationship of appointment frequency with survival was observed for patients in any treatment group.

Conclusions

The practice of routine follow-up varies and is costly both to a health care system and to patients. Without evidence about the effectiveness of current policies, further research is required to investigate new or optimal practices.

A-68 Yoga Therapy in Pediatric Epilepsy

Objective

This pilot study examines the effects of yoga therapy on anxiety, depression symptoms, inattention, and seizure frequency in children diagnosed with Epilepsy.

Data Selection

The sample consisted of 5 participants (4 male, 1 female), ages 7-12 years old, with diagnoses of generalized epilepsy, absence epilepsy, and complex partial epilepsy. Participants all had average cognitive abilities (IQ SS = 100.7; VCI SS = 106.3; PRI SS = 108.3), a diagnosis of Attention Deficit Hyperactivity Disorder (ADHD), and clinically significant levels of anxiety and depression. Participants participated in 30-45-minute-long yoga sessions over a 6-week period with 2-3 home sessions each week. Differences in hyperactivity, anxiety, depression, and inattention were measured via parent rating Likert scales (0-poor, 10-best) at 1 month, 3 months, and 6 months. Participants also completed weekly self-report measures to assess anxiety and depression (Revised Children’s Manifest Anxiety, Second Edition (RCMAS-2) and Children’s Depression Inventory, Second Edition (CDI-2)).

Data Synthesis

No significant reliable change differences were found between sessions; however, a downward trend was visible in reduction of anxiety (RCMAS-2; first session M = 16.4, last session M = 9.4) and depression symptoms (CDI-2; first session M = 52.8, last session M = 49.2). Further, parents reported a decrease in anxiety (first session M = 4.8, last session M = 6.4). No seizures were reported during the study.

Conclusions

There is no previous research using pediatric populations and yoga therapy effects on reducing seizure frequency, anxiety, depression, and attention problems. This pilot study showed promising results in reducing anxiety, and depression symptoms. Limitations of study include small sample size and attrition, which are both important to consider when conducting another study.

Jupiter's interior and deep atmosphere: The initial pole-to-pole passes with the Juno spacecraft

On 27 August 2016, the Juno spacecraft acquired science observations of Jupiter, passing less than 5000 kilometers above the equatorial cloud tops. Images of Jupiter's poles show a chaotic scene, unlike Saturn's poles. Microwave sounding reveals weather features at pressures deeper than 100 bars, dominated by an ammonia-rich, narrow low-latitude plume resembling a deeper, wider version of Earth's Hadley cell. Near-infrared mapping reveals the relative humidity within prominent downwelling regions. Juno's measured gravity field differs substantially from the last available estimate and is one order of magnitude more precise. This has implications for the distribution of heavy elements in the interior, including the existence and mass of Jupiter's core. The observed magnetic field exhibits smaller spatial variations than expected, indicative of a rich harmonic content.

Direct analysis of volatile organic compounds in foods by headspace extraction atmospheric pressure chemical ionisation mass spectrometry

RATIONALE

The rapid screening of volatile organic compounds (VOCs) by direct analysis has potential applications in the areas of food and flavour science. Currently, the technique of choice for VOC analysis is gas chromatography/mass spectrometry (GC/MS). However, the long chromatographic run times and elaborate sample preparation associated with this technique have led a movement towards direct analysis techniques, such as selected ion flow tube mass spectrometry (SIFT-MS), proton transfer reaction mass spectrometry (PTR-MS) and electronic noses. The work presented here describes the design and construction of a Venturi jet-pump-based modification for a compact mass spectrometer which enables the direct introduction of volatiles for qualitative and quantitative analysis.

METHODS

Volatile organic compounds were extracted from the headspace of heated vials into the atmospheric pressure chemical ionization source of a quadrupole mass spectrometer using a Venturi pump. Samples were analysed directly with no prior sample preparation. Principal component analysis (PCA) was used to differentiate between different classes of samples.

RESULTS

The interface is shown to be able to routinely detect problem analytes such as fatty acids and biogenic amines without the requirement of a derivatisation step, and is shown to be able to discriminate between four different varieties of cheese with good intra and inter-day reproducibility using an unsupervised PCA model. Quantitative analysis is demonstrated using indole standards with limits of detection and quantification of 0.395 μg/mL and 1.316 μg/mL, respectively.

CONCLUSIONS

The described methodology can routinely detect highly reactive analytes such as volatile fatty acids and diamines without the need for a derivatisation step or lengthy chromatographic separations. The capability of the system was demonstrated by discriminating between different varieties of cheese and monitoring the spoilage of meats.

D2O and HDS in the coma of 67P/Churyumov-Gerasimenko

The European Rosetta mission has been following comet 67P/Churyumov-Gerasimenko for 2 years, studying the nucleus and coma in great detail. For most of these 2 years the Rosetta Orbiter Sensor for Ion and Neutral Analysis (ROSINA) has analysed the volatile part of the coma. With its high mass resolution and sensitivity it was able to not only detect deuterated water HDO, but also doubly deuterated water, D₂O and deuterated hydrogen sulfide HDS. The ratios for [HDO]/[H₂O], [D₂O]/[HDO] and [HDS]/[H₂S] derived from our measurements are (1.05 ± 0.14) × 10^-3, (1.80 ± 0.9) × 10^-2 and (1.2 ± 0.3) × 10^-3, respectively. These results yield a very high ratio of 17 for [D₂O]/[HDO] relative to [HDO]/[H₂O]. Statistically one would expect just 1/4. Such a high value can be explained by cometary water coming unprocessed from the presolar cloud, where water is formed on grains, leading to high deuterium fractionation. The high [HDS]/[H₂S] ratio is compatible with upper limits determined in low-mass star-forming regions and also points to a direct correlation of cometary H₂S with presolar grain surface chemistry.This article is part of the themed issue 'Cometary science after Rosetta'.

Reasons for palliative treatments in stage III non-small-cell lung cancer: what contribution is made by time-dependent changes in tumour or patient status?

INTRODUCTION

Stage iii lung cancer is the most advanced stage of lung cancer for which the potential of curative treatment is often discussed. However, a large proportion of patients are treated with palliative intent. An understanding of the time-dependent and -independent factors contributing to the choice of palliative-intent treatment is needed to help optimize patient outcomes.

METHODS

This retrospective cohort study of patients with stage iii non-small-cell lung cancer (nsclc) newly diagnosed between 1 January 2008 and 31 December 2012 at the Cancer Centre of Southeastern Ontario collected data including patient demographics, clinical characteristics, tumour characteristics, treatment, and outcomes.

RESULTS

Of 237 patients with stage iii nsclc included in the study, 130 were not treated with radical or curative intent (55%). Major time-independent variables cited for palliative-intent treatment included extreme age (5%), comorbidity (27%), patient choice (5%), and poor lung function (5%). Time-dependent variables included tumour progression on imaging (15%), weight loss (33%), performance status (32%), and the occurrence of a major complication such as hemoptysis, lung collapse, or pulmonary embolism (7%). A significant number of patients (20%) experienced a decline in performance status-to 2, 3, or 4 from 0 or 1-over the course of the diagnostic journey, and 12% experienced a transition from no weight loss to more than 10% weight loss.

CONCLUSIONS

A significant proportion of patients receive palliative therapy for stage iii nsclc because of changes that occur during the diagnostic journey. Shortening or altering that pathway to avoid tumour growth or patient deterioration during care could allow for more patients to be treated with curative intent.

Causes of death and subsequent treatment after initial radical or palliative therapy of stage III non-small-cell lung cancer

INTRODUCTION

Stage iii lung cancer is the most advanced stage of lung cancer for which radical (potentially curative) treatment is often discussed. Understanding the reasons for mortality and subsequent treatments in patients with stage iii non-small-cell lung cancer (nsclc) is important.

METHODS

This retrospective cohort study extracted demographic, clinical, treatment, and outcomes data for patients with newly diagnosed stage iii nsclc diagnosed between 1 January 2008 and 31 December 2012 at a single institution.

RESULTS

The study included 237 patients with stage iii nsclc, 130 of whom were not treated with radical or curative intent (55%). Median survival in the entire cohort was 14 months from diagnosis. For patients treated with radical-intent therapy, causes of death varied with the time period. The hazard rate for death was approximately 2.8 per 100 person-months of follow-up over the entire disease course and was highest between 6 months and 24 months. Over the entire time period, local causes accounted for 29% of deaths; systemic non-central nervous system metastases, for 25%; and brain metastases, for 14%. For patients treated with palliative intent, the overwhelming cause of death was local disease complications or progression (56% of deaths). Only 12% of patients in the palliative treatment group who progressed received subsequent chemotherapy; 23% of patients in the radical group who progressed received palliative chemotherapy. The most frequent subsequent treatment in both groups was radiation therapy.

CONCLUSIONS

The eventual life-ending event in stage iii nsclc varied for the patients who qualified for, and were treated with, radical or curative intent and for the patients who received palliative-intent therapy. Utilization of systemic chemotherapy in patients not fit for radical therapy is low.

Perioperative myocardial injury in patients receiving cardiac output-guided haemodynamic therapy: a substudy of the OPTIMISE Trial

BACKGROUND

Evidence suggests that cardiac output-guided haemodynamic therapy algorithms improve outcomes after high-risk surgery, but there is some concern that this could promote acute myocardial injury. We evaluated the incidence of myocardial injury in a perioperative goal-directed therapy trial.

METHODS

Patients undergoing major gastrointestinal surgery (n=723) were randomly assigned to cardiac output-guided haemodynamic therapy (intervention group) or usual care as part of the OPTIMISE trial. At four participating sites, 288 patients were enrolled in a biomarker substudy. Serum high-sensitivity cardiac troponin I (TnI) concentration and N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration were measured before and at 24 and 72 h after surgery.

RESULTS

Median preoperative TnI and NT-ProBNP concentrations were 4.3 ng litre(-1) and 144 pg ml(-1), respectively. After surgery, 67 (46%) patients in the intervention group and 68 (48%) patients receiving usual care had TnI concentrations above the 99th centile upper reference limit (P=0.82). Peak serum TnI concentration was similar in the intervention and usual care groups (median [interquartile range]: 10.0 [5.3-21.5] vs 7.8 [5.0-21.8] ng litre(-1); P=0.85), and no differences were observed in serum TnI concentrations over 72 h (repeated-measures anova, P=0.51). Likewise, there were no differences in peak NT-proBNP concentration between intervention and usual care groups (645 [362-1169] vs 659 [381-1028] pg ml(-1); P=0.86) or in serial NT-proBNP concentrations over 72 h (P=0.20).

CONCLUSIONS

Myocardial injury is common among patients undergoing major gastrointestinal surgery. In this study, the frequency was not affected by cardiac output-guided fluid and low-dose inotropic therapy.

Molecular nitrogen in comet 67P/Churyumov-Gerasimenko indicates a low formation temperature

Molecular nitrogen (N2) is thought to have been the most abundant form of nitrogen in the protosolar nebula. It is the main N-bearing molecule in the atmospheres of Pluto and Triton and probably the main nitrogen reservoir from which the giant planets formed. Yet in comets, often considered the most primitive bodies in the solar system, N2 has not been detected. Here we report the direct in situ measurement of N2 in the Jupiter family comet 67P/Churyumov-Gerasimenko, made by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis mass spectrometer aboard the Rosetta spacecraft. A N2/CO ratio of (5.70 ± 0.66) × 10(-3) (2σ standard deviation of the sampled mean) corresponds to depletion by a factor of ~25.4 ± 8.9 as compared to the protosolar value. This depletion suggests that cometary grains formed at low-temperature conditions below ~30 kelvin.

Cometary science. Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko

Comets contain the best-preserved material from the beginning of our planetary system. Their nuclei and comae composition reveal clues about physical and chemical conditions during the early solar system when comets formed. ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) onboard the Rosetta spacecraft has measured the coma composition of comet 67P/Churyumov-Gerasimenko with well-sampled time resolution per rotation. Measurements were made over many comet rotation periods and a wide range of latitudes. These measurements show large fluctuations in composition in a heterogeneous coma that has diurnal and possibly seasonal variations in the major outgassing species: water, carbon monoxide, and carbon dioxide. These results indicate a complex coma-nucleus relationship where seasonal variations may be driven by temperature differences just below the comet surface.

Voyager 2 in the uranian system: imaging science results

Voyager 2 images of the southern hemisphere of Uranus indicate that submicrometersize haze particles and particles of a methane condensation cloud produce faint patterns in the atmosphere. The alignment of the cloud bands is similar to that of bands on Jupiter and Saturn, but the zonal winds are nearly opposite. At mid-latitudes (-70 degrees to -27 degrees ), where winds were measured, the atmosphere rotates faster than the magnetic field; however, the rotation rate of the atmosphere decreases toward the equator, so that the two probably corotate at about -20 degrees . Voyager images confirm the extremely low albedo of the ring particles. High phase angle images reveal on the order of 10(2) new ringlike features of very low optical depth and relatively high dust abundance interspersed within the main rings, as well as a broad, diffuse, low optical depth ring just inside the main rings system. Nine of the newly discovered small satellites (40 to 165 kilometers in diameter) orbit between the rings and Miranda; the tenth is within the ring system. Two of these small objects may gravitationally confine the e ring. Oberon and Umbriel have heavily cratered surfaces resembling the ancient cratered highlands of Earth's moon, although Umbriel is almost completely covered with uniform dark material, which perhaps indicates some ongoing process. Titania and Ariel show crater populations different from those on Oberon and Umbriel; these were probably generated by collisions with debris confined to their orbits. Titania and Ariel also show many extensional fault systems; Ariel shows strong evidence for the presence of extrusive material. About halfof Miranda's surface is relatively bland, old, cratered terrain. The remainder comprises three large regions of younger terrain, each rectangular to ovoid in plan, that display complex sets of parallel and intersecting scarps and ridges as well as numerous outcrops of bright and dark materials, perhaps suggesting some exotic composition.

Offering a prognosis in lung cancer: when is a team of experts an expert team?

The outlook for patients with lung cancer is poor, so an accurate estimation of prognosis will underpin treatment decisions and allow patients to make personal plans for the future. However, evidence suggests that there is a variation between doctors in their predictions of outcomes and also they tend to be over-optimistic. Two main questions are addressed in this study: whether multidisciplinary team discussion changes prognostic accuracy of individual clinicians; and whether team discussion improves the accuracy of the team's aggregated prediction. A real-time study of 50 newly diagnosed patients discussed by a regional lung cancer team was undertaken. A case pro-forma informed the completion of a pre-discussion questionnaire by each team member, seeking prognostic predictions at specific time points. This was repeated after team discussion. Medical notes were reviewed at 6 months to establish actual survival status. Group discussion did not significantly change the accuracy of survival predictions for any one clinician, but the team as a whole performed better after case discussion. Predictions which the clinicians were more confident about were found to be no more accurate than those where they were less confident. There is a wide variation in the range and accuracy of prognostic predictions made by individual clinicians, with no consistent improvement after team discussion. As such predictions are integral to decision making, further research on decision-making processes of clinical teams is required.

Complex organic matter in Titan's atmospheric aerosols from in situ pyrolysis and analysis

Aerosols in Titan's atmosphere play an important role in determining its thermal structure. They also serve as sinks for organic vapours and can act as condensation nuclei for the formation of clouds, where the condensation efficiency will depend on the chemical composition of the aerosols. So far, however, no direct information has been available on the chemical composition of these particles. Here we report an in situ chemical analysis of Titan's aerosols by pyrolysis at 600 degrees C. Ammonia (NH3) and hydrogen cyanide (HCN) have been identified as the main pyrolysis products. This clearly shows that the aerosol particles include a solid organic refractory core. NH3 and HCN are gaseous chemical fingerprints of the complex organics that constitute this core, and their presence demonstrates that carbon and nitrogen are in the aerosols.

Knowledge, attitudes and behaviour in the sun: the barriers to behavioural change in Northern Ireland

To inform future health promotion programmes, we studied the knowledge, attitudes and behaviour of the Northern Ireland population to sun care. An interviewer-administered questionnaire was applied to one adult per household from a random sample of 1242 addresses. Lower levels of knowledge were found among respondents who were male, aged under 25 years or over 65 years, in a manual occupation or living in the west where health promotion activity on this topic was less active than in the east. Younger adults, females and professional groups were more likely to indicate that a suntan was important, healthy or attractive. Use of high factor sunscreen was inversely proportional to perceived importance of a suntan. Sunburn was more common in younger adults but more men reported multiple episodes of burning. Regular skin checks were uncommon and self-assessment of skin type was unrealistic indicating that sun care advice based on self assessment should be avoided in this population. Future campaigns should target appropriate messages at specific population subgroups. The study highlights the importance of collecting baseline information before implementing health promotion programmes and suggests that repeat monitoring is essential to ensure that key messages remain relevant. This study also indicates that Care in the Sun campaigns here impacted on general awareness in the population even with limited resources. There is, therefore, potential for greater impact with high funding levels.

Life as a planetary phenomenon

The success of recent spacecraft from the U.S.A. and the U.S.S.R. has given us a wealth of new data about the planets in our solar system. We can now develop a much better rationale for the reasons that abundant life is only found on our planet. Mars, smaller and more distant from the Sun, may nevertheless hold clues to the early development of Earth's atmosphere. The origin of life on Mars early in that planet's history cannot be ruled out. Titan offers a contemporary example of extremely primitive conditions, where chemical reactions resembling those that preceded the development of life on Earth may be occurring today. Venus and Jupiter illustrate the need for a planet to be the right size and the right distance from the sun if chemical evolution leading to the origin of life is to occur.

The origin of inner planet atmospheres

In a series of laboratory experiments, A. Bar-Nun and colleagues (Bar-Nun et al . 1985, 1988; Owen et al . 1991) have succeeded in analysing the amounts of gases trapped in amorphous ice forming at low temperatures (16-190 K). They found that a temperature-dependent fractionation of noble gases occurs. The relative abundances of argon, krypton and xenon trapped by ice formed at 50 K fit an extrapolated mixing line that passes through points for the abundances of these same gases in the atmospheres of Mars and Earth on a three-isotope plot. The noble gases in the Shergottites, one of the three types of meteorites originating on Mars, also fall on this line (figure 1). A study of the xenon isotopes in the Shergottites and Nakhlites (a second type of Martian meteorite) suggest that these meteorites contain gases from the Martian interior and atmosphere, and the Shergottites may also include a component from the impactor that expelled them from the planet (Owen & Bar-Nun 1993). Taken together, these data provide a good indication that icy planetesimals (comets) that formed in the Uranus-Neptune region (T ~ 50 K) played a major role in delivering the noble gases to Mars and the Earth. Venus could have obtained its noble gases from the impact(s) of one or more comets formed at the lower temperatures (T ~ 30 K) prevailing in the Kuiper Belt (Owen et al . 1992; Owen Bar-Nun 1993). Given that ice is the carrier, one naturally expects that comets could have brought in all the volatiles. This idea is buttressed by a study of nitrogen. The same laboratory experiments referenced above demonstrate that CO is trapped twenty times more efficiently than N 2 in ice forming at 50 K. Since N 2 is expected to be the dominant carrier of nitrogen in the solar nebula, whereas CO is likely to contain no more that 15-30% of the total carbon, this would lead to a severe depletion of nitrogen in icy planetesimals. In evaluating C/N in Halley’s comet, the atmospheres of Venus and Mars, and the volatile inventory of the Earth, one sees exactly this effect. In all four inventories C/N = 20 ± 10, whereas the solar value is 3.2. Thus we again discover support for the cometary delivery hypothesis (Owen & Bar-Nun 1994).

Fractionated martian atmosphere in the nakhlites?

Considerable evidence points to a martian origin of the SNC meteorites. Noble gas isotopic compositions have been measured in most SNC meteorites. The 129Xe/132Xe vs, 84Kr/132Xe ratios in Chassigny, most shergottites, and lithology C of EETA 79001 define a linear array. This array is thought to be a mixing line between martian mantle and martian atmosphere. One of the SNC meteorites, Nakhla, contains a leachable component that has an elevated 129Xe/132Xe ratio relative to its 84Kr/132Xe ratio when compared to this approximately linear array. The leachable component probably consists in part of iddingsite, an alteration product produced by interaction of olivine with aqueous fluid at temperatures lower than 150 degrees C. The elevated Xe isotopic ratio may represent a distinct reservoir in the martian crust or mantle. More plausibly, it is elementally fractionated martian atmosphere. Formation of sediments fractionates the noble gases in the correct direction. The range of sediment/atmosphere fractionation factors is consistent with the elevated 129Xe/132Xe component in Nakhla being contained in iddingsite, a low temperature weathering product. The crystallization age of Nakhla is 1.3 Ga. Its low-shock state suggests that it was ejected from near the surface of Mars. As liquid water is required for the formation of iddingsite, these observations provide further evidence for the near surface existence of aqueous fluids on Mars more recently than 1.3 Ga.

A low-temperature origin for the planetesimals that formed Jupiter

The four giant planets in the Solar System have abundances of 'metals' (elements heavier than helium), relative to hydrogen, that are much higher than observed in the Sun. In order to explain this, all models for the formation of these planets rely on an influx of solid planetesimals. It is generally assumed that these planetesimals were similar, if not identical, to the comets from the Oort cloud that we see today. Comets that formed in the region of the giant planets should not have contained much neon, argon and nitrogen, because the temperatures were too high for these volatile gases to be trapped effectively in ice. This means that the abundances of those elements on the giant planets should be approximately solar. Here we show that argon, krypton and xenon in Jupiter's atmosphere are enriched to the same extent as the other heavy elements, which suggests that the planetesimals carrying these elements must have formed at temperatures lower than predicted by present models of giant-planet formation.

An experimental study of the isotopic enrichment in Ar, Kr, and Xe when trapped in water ice

The isotopic enrichment of argon, krypton, and xenon, when trapped in water ice, was studied experimentally. The isotopes were found to be enriched according to their (m1/m2)1/2 ratio. These enrichment factors could be useful for comparison among the uncertain cosmic or solar isotopic ratios, the hopeful in situ cometary ratio, and those in Earth's atmosphere, in the context of cometary delivery of volatiles to Earth.

Transient clouds in Titan's lower atmosphere

The 1980 encounter by the Voyager 1 spacecraft with Titan, Saturn's largest moon, revealed the presence of a thick atmosphere containing nitrogen and methane (1.4 and approximately 0.05 bar, respectively). Methane was found to be nearly saturated at Titan's tropopause, which, with other considerations, led to the hypothesis that Titan might experience a methane analogue of Earth's vigorous hydrological cycle, with clouds, rain and seas. Yet recent analyses of Voyager data indicate large areas of super-saturated methane, more indicative of dry and stagnant conditions. A resolution to this apparent contradiction requires observations of Titan's lower atmosphere, which was hidden from the Voyager cameras by the photochemical haze (or smog) in Titan's stratosphere. Here we report near-infrared spectroscopic observations of Titan within four narrow spectral windows where the moon's atmosphere is ostensibly transparent. We detect pronounced flux enhancements that indicate the presence of reflective methane condensation clouds in the troposphere. These clouds occur at a relatively low altitude (15+/-10 km), at low latitudes, and appear to cover approximately 9 per cent of Titan's disk.

Estrogen Receptor-α Is Developmentally Regulated during Osteoblast Differentiation and Contributes to Selective Responsiveness of Gene Expression

Estrogen responsiveness of bone is a fundamental regulatory mechanism operative in skeletal homeostasis. We examined the expression of estrogen receptor-alpha (ER) messenger RNA (mRNA) in cultured rat calvarial-derived osteoblasts during progressive development of the osteoblast phenotype. Levels of ER message were compared with the expression of traditional osteoblastic markers that have been mapped throughout the differentiation process of these cells. ER transcripts, measured using semiquantitative RT-PCR analysis, were expressed at low levels in early stage proliferating osteoblasts and increased at confluence upon initial expression of bone cell phenotypic genes. A 23-fold up-regulation of ER mRNA expression coincided with the initiation of alkaline phosphatase activity (day 8). ER mRNA levels progressively increased 70-fold, reaching a maximum level on days 22-25 in fully differentiated osteoblasts when osteocalcin expression peaked, but declined precipitously by day 32 in osteocytic cells. Analysis of RNA isolated directly from rat calvaria confirmed these in vitro results and demonstrated that ER message levels become more abundant postnatally as bone becomes more mineralized. We also examined the responsiveness of osteoblasts to 17beta-estradiol (17beta-E2) at two periods of maturation: the nodule-forming stage (day 14) and the late mineralization stage (day 30). Estradiol suppressed the levels of alkaline phosphatase, osteocalcin, osteonectin, and ER mRNAs on day 14, but up-regulated these messages on day 30. In contrast, 17beta-E2 treatment regulated the steady state levels of transforming growth factor-beta1 and type I procollagen mRNAs only in the late mineralization stage, whereas histone H4 message was unaffected by the steroid at either stage of differentiation. Thus, the observed developmental expression of ER mRNA correlates with progressive osteoblast differentiation and may be a contributing factor to differential regulation of bone cell gene expression by 17beta-E2.

Titan and the origin of life on Earth

The relevance of Titan to the study of pre-biotic chemistry and the origin of life on Earth will be addressed by an interdisciplinary group of Cassini/Huygens scientists using the different, but synergistic data sets obtained by NASA's Cassini Orbiter and ESA's Huygens Probe. Titan's special importance lies in the primitive chemically-reducing nature of its atmosphere Cassini/ Huygens instruments will determine what compounds form in this environment, and the results will be compared with models for pre-biological chemical evolution on Earth.

Measurements of 12C/13C, 14N/15N, and 32S/34S ratios in comet Hale-Bopp (C/1995 O1)

The 12C/13C, 14N/15N, and 32S/34S isotope ratios in comet Hale-Bopp (C/1995 O1) were determined through observations taken with the James Clerk Maxwell Telescope. Measurements of rare isotopes in HCN and CS revealed isotope ratios of H12CN/H13CN = 111 +/- 12, HC14N/HC15N = 323 +/- 46, and C32S/C34S = 27 +/- 3. Within the measurement uncertainties, the isotopic ratios are consistent with solar system values. The cometary volatiles thus have an origin in the solar system and show no evidence for an interstellar component.

The impact of heart health promotion on coronary heart disease lifestyle risk factors in schoolchildren: lessons learnt from a community-based project

A community health promotion project called Action Heart was undertaken in two electoral wards in Rotherham to try to change lifestyles of people. Schools were included within the project. Coronary heart disease lifestyle risk factors were measured at baseline and after a three year period in the intervention area and a similar control area. Lifestyle factors in schoolchildren were measured separately from adults using a different instrument. The post intervention survey of adults and economic evaluation demonstrated that Action Heart had achieved cost-effective estimated health gains. In the schoolchildren however, a mixture of positive and negative risk factor changes in both areas was demonstrated. Significant changes in lifestyle risk factors in schoolchildren were not elicited using this approach. The possible reasons for the lack of impact on lifestyle risk factors in schoolchildren are examined and the implications for further work explored.

Comets, meteorites and atmospheres

The relatively low value of Xe/Kr in the atmospheres of Earth and Mars seems to rule out meteorites as the major carriers of noble gases to the inner planets. Laboratory experiments on the trapping of gases in ice forming at low temperatures suggest that comets may be a better choice. It is then possible to develop a model for the origin of inner planet atmospheres based on volatiles delivered by comets added to volatiles originally trapped in planetary rocks. The model will be tested by results from the Galileo Entry Probe.

Who should give lifestyle advice in general practice and what factors influence attendance at health promotion clinics? Survey of patients' views

BACKGROUND

Health promotion activity in general practice has increased greatly since 1990. A large proportion of this work is undertaken by practice nurses. Little is known about patients' views about the providers of health promotion or their views about general practice health promotion clinics.

AIM

A study was carried out in 1992 to determine patients' views about the provision of health promotion advice by general practitioners and practice nurses and their views about attending health promotion clinics.

METHOD

A postal questionnaire was sent to a random sample of 1750 patients aged 16 years and over from five general practices in south Tyneside. The questionnaire explored patients' preferences regarding health promotion advice from the general practitioner or practice nurse in relation to four areas of lifestyle advice and factors that might encourage patients to attend a health promotion clinic.

RESULTS

A response rate of 75% was obtained from 1639 eligible patients. Receiving health promotion advice from either the general practitioner or the practice nurse was the most commonly preferred option expressed by patients overall. The ability of health promotion clinic staff to deal with patients' concerns about their illness and short waiting times were more likely to influence patients' attendance at health promotion clinics than the presence of a general practitioner or practice nurse.

CONCLUSION

In the present study, many patients found health advice received from practice nurses and general practitioners equally acceptable. However, it was the ability of health professionals to respond to patients' health concerns in the health promotion clinic rather than the type of health professional running the clinic that was important for patients.