Atomic clock performance enabling geodesy below the centimetre level.

The passage of time is tracked by counting oscillations of a frequency reference, such as Earth's revolutions or swings of a pendulum. By referencing atomic transitions, frequency (and thus time) can be measured more precisely than any other physical quantity, with the current generation of optical atomic clocks reporting fractional performance below the 10-17 level1-5. However, the theory of relativity prescribes that the passage of time is not absolute, but is affected by an observer's reference frame. Consequently, clock measurements exhibit sensitivity to relative velocity, acceleration and gravity potential. Here we demonstrate local optical clock measurements that surpass the current ability to account for the gravitational distortion of space-time across the surface of Earth. In two independent ytterbium optical lattice clocks, we demonstrate unprecedented values of three fundamental benchmarks of clock performance. In units of the clock frequency, we report systematic uncertainty of 1.4 × 10-18, measurement instability of 3.2 × 10-19 and reproducibility characterized by ten blinded frequency comparisons, yielding a frequency difference of [-7 ± (5)stat ± (8)sys] × 10-19, where 'stat' and 'sys' indicate statistical and systematic uncertainty, respectively. Although sensitivity to differences in gravity potential could degrade the performance of the clocks as terrestrial standards of time, this same sensitivity can be used as a very sensitive probe of geopotential5-9. Near the surface of Earth, clock comparisons at the 1 × 10-18 level provide a resolution of one centimetre along the direction of gravity, so the performance of these clocks should enable geodesy beyond the state-of-the-art level. These optical clocks could further be used to explore geophysical phenomena10, detect gravitational waves11, test general relativity12 and search for dark matter13-17.

Hyperpolarizability and Operational Magic Wavelength in an Optical Lattice Clock.

Optical clocks benefit from tight atomic confinement enabling extended interrogation times as well as Doppler- and recoil-free operation. However, these benefits come at the cost of frequency shifts that, if not properly controlled, may degrade clock accuracy. Numerous theoretical studies have predicted optical lattice clock frequency shifts that scale nonlinearly with trap depth. To experimentally observe and constrain these shifts in an ^{171}Yb optical lattice clock, we construct a lattice enhancement cavity that exaggerates the light shifts. We observe an atomic temperature that is proportional to the optical trap depth, fundamentally altering the scaling of trap-induced light shifts and simplifying their parametrization. We identify an "operational" magic wavelength where frequency shifts are insensitive to changes in trap depth. These measurements and scaling analysis constitute an essential systematic characterization for clock operation at the 10^{-18} level and beyond.

Nutritional status, metabolic state and nutrient intake in children with bronchiolitis.

Nutrition has a coadjuvant role in the management of children with acute diseases. We aimed to examine nutritional status, macronutrient requirements and actual macronutrient delivery in bronchiolitis. The nutritional status was classified according to WHO criteria and resting energy expenditure (MREE) was measured using an indirect calorimeter. Bland-Altman analysis was used to examine the agreement between MREE and estimated energy expenditure (EEE) with standard equations. Based on the ratio MREE/EEE in relation to Schofield equation on admission, we defined the subjects' metabolic status. A total of 35 patients were enrolled and 46% were malnourished on admission, and 25.8% were hypermetabolic, 37.1% hypometabolic and 37.1% normometabolic. We performed a 24-h recall in 10 children and 80% were overfed (AEI: MREE >120%). Mean bias (limits of agreement) with MREE was 8.9 (-73.9 to 91.8%) for Schofield; 61.0 (-41 to 163%) for Harris-Benedict; and 9.9 (-74.4 to 94.2%) for FAO-WHO equation. Metabolism of infants with bronchiolitis is not accurately estimated by equations.

[Prenatal path of care following the diagnosis of a malformation for which a novel prenatal therapy is available]. / Parcours prénatal devant une malformation pour laquelle un traitement in utero émergent est disponible.

OBJECTIVES: Fetal therapy is part of the available care offer for several severe malformations. The place of these emergent prenatal interventions in the prenatal path of care is poorly known. The objective of this study is to describe the decision-making process of patients facing the option of an emergent in utero intervention. METHODS: We have conducted a retrospective monocentric descriptive study in the department of maternal-fetal medicine of Necker Hospital. We collected data regarding eligibility or not for fetal surgery and the pregnancy outcomes of patients referred for myelomeningocele, diaphragmatic hernia, aortic stenosis and low obstructive uropathies. RESULTS: All indications combined, 70% of patients opted for fetal surgery. This rate was lower in the case of myelomeningocele with 21% consent, than in the other pathologies: 69% for diaphragmatic hernias, 90% for aortic stenoses and 76% for uropathy. When fetal intervention was declined, the vast majority of patients opted for termination of pregnancy: 86%. In 14% of the considering fetal surgery, the patient was referred too far. CONCLUSION: The acceptance rate for fetal surgeries depends on condition. It offers an additional option and is an alternative for couples for which termination of pregnancy (TOP) is not an option. Timely referral to an expert center allows to discuss the place of a fetal intervention and not to deprive couples of this possibility.

CC ligand 2 levels are increased in LPS-stimulated peripheral monocytes of patients with non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) shows a particular aggressive behaviour. Tumour associated macrophages (TAMs) play an important role in tumour growth and progression and CC ligand 2 (CCL2)/CCR2 axis is markedly involved in their recruitment in the tumour mass from the circulation. The aim of this study was to determine the plasma levels of CCL2 and the expression of CCR2 in the peripheral blood mononuclear cells (PBMCs) of 18 smokers with NSCLC, eight healthy smokers and nine non-smokers. Then, we investigated CCL2 levels in the supernatants of unstimulated and LPS-stimulated PBMC cultures of the same groups of patients. CCL2 levels in plasma and supernatants of PBMC cultures were determined by ELISA. CCR2 expression in PBMC cytospins was assessed by immunocytochemistry. CCL2 plasma levels and CCR2 expression by PBMCs were similar in patients with NSCLC, healthy smokers and non-smokers. In the supernatants of unstimulated PBMC cultures, CCL2 content was not different between the three groups of subjects. Supernatants of LPS-stimulated PBMCs of NSCLC patients showed a higher content of CCL2 as compared to supernatants of non-smokers (p<0.005). CCL2 content increased 28.5-fold vs baseline production in the group of NSCLC patients, 15-fold in healthy smokers and 13-fold in the group of non-smokers. In conclusion, after LPS stimulation, PBMCs of patients with NSCLC release higher levels of CCL2 as compared to those of non-smokers, supporting the hypothesis of a CCL2 involvement in NSCLC biology.

Automatic pedigree reconstruction for genetic studies in isolated populations.

This paper describes a tool implemented to automatically reconstruct the pedigree of an isolated population of Northern Italy with the aim of supporting genetic studies. The goal of such studies is to analyze genealogic, clinical and genetic data for genetic dissection of complex diseases. In this context the reconstruction of the population pedigree is fundamental to verify that such population is a genetic isolate and obtain the parental relationships among the individuals participating to the study. The algorithm presented in the paper, from heterogeneous data sources (demographic municipal and parish archives and other data sources), derives the pedigree applying several heuristic rules in a predefined order. One of the main difficulties in performing such task stands in the "record linkage" process that requires the definition of a sufficiently general strategy for managing the ambiguities caused by missing or imprecise/erroneous input data. The paper, finally, presents and discusses the preliminary results obtained by reconstructing the pedigree of four villages from the data collected during the first eighteen months of project.

Follow-up of children exposed to ionising radiation from cardiac catheterisation: the Coccinelle study.

Cardiac catheterisation has become an essential tool in the diagnosis and treatment of children with a wide variety of congenital and acquired forms of cardiovascular disease. Despite the clear clinical benefit to the patient, radiation exposure from paediatric cardiac catheterisation procedures (CCPs) may be substantial. Given children's greater sensitivity to radiation and the longer life span during which radiation health effects can develop, an epidemiological cohort study, named Coccinelle or 'Ladybird' (French acronym for 'Cohorte sur le risque de cancer après cardiologie interventionnelle pédiatrique'), is carried out in France to evaluate the risks of leukaemia and solid cancers in this population. A total number of 8000 included children are expected. Individual CCP-related doses will be assessed for each child included in the cohort. For each CCP performed, dosimetric parameters (dose-area product, fluoroscopy time and total number of cine frames) are retrieved retrospectively. Organ doses, especially to the lung, the oesophagus and the thyroid, are calculated with PCXMC software. The cohort will be followed up through linkage with French paediatric cancer registries.

Growth hormone (GH) responses to GH-releasing hormone alone or combined with arginine in patients with adrenal incidentaloma: evidence for enhanced somatostatinergic tone.

Spontaneous and stimulated GH secretion is blunted in hypercortisolemic states due to increased hypothalamic somatostatinergic tone. However, no data are available on the characteristics of GH secretion in patients with incidentally discovered adrenal adenomas. They represent an interesting model for studying GH secretion, as a slight degree of cortisol excess may frequently be observed in such patients who do not present with any clear Cushingoid sign. In the present study, 10 patients (3 men and 7 women, aged 48-63 yr) with an adrenal mass discovered serendipitously underwent, on separate occasions, a GHRH injection alone or combined with an infusion of the functional somatostatin antagonist, arginine. Thirteen age-matched healthy volunteers served as controls. Briefly, arginine (30 g) was infused from -30 to 0 min, and GHRH (100 microg) was injected as a bolus at 0 min, with measurement of serum GH [immunoradiometric assay (IRMA)] every 15 min for 150 min. Plasma IGF-I (RIA after acid-ethanol extraction) was measured in a morning sample. The diagnosis of cortical adenoma was based on computed tomography features and pattern of uptake on adrenal scintigraphy. Patients with obesity and/or diabetes were excluded. The study design included also an endocrine work-up aimed to study the hypothalamic-pituitary-adrenal axis [urinary free cortisol (UFC) excretion, serum cortisol at 0800 h, plasma ACTH at 0800 h, morning cortisol after overnight 1 mg dexamethasone]. Five of 10 patients showed abnormalities of the hypothalamic-pituitary-adrenal axis, including borderline or increased UFC excretion in 4 of them accompanied by blunted ACTH in 2 cases and failure of cortisol to suppress after dexamethasone in 1; the fifth patient displayed low ACTH and resistance to dexamethasone suppression. However, all patients had a unilateral uptake of the tracer on the side of the mass with suppression of the contralateral normal adrenal gland. As a group, the patients displayed greater UFC excretion and lower ACTH concentrations than the controls. GH release after GHRH treatment was blunted in patients bearing adrenal incidentaloma compared with controls (GH peak, 5.7 +/- 5.2 vs. 18.0 +/- 7.0 microg/L; P < 0.0001), whereas GHRH plus arginine was able to elicit a comparable response in the 2 groups (GH peak, 33.5 +/- 20.3 vs. 33.7 +/- 17.5 microg/L; P = NS). The ratio between GH peaks after GHRH plus arginine and after GHRH plus saline was significantly greater in patients than in controls (751 +/- 531% vs. 81 +/- 45%; P = 0.0001). Similar data were obtained when comparing GH area under the curve after GHRH plus saline or GHRH plus arginine between the 2 groups. In summary, the present data suggest that in patients with incidental adrenal adenomas the GH response to GHRH is blunted due to increased somatostatinergic tone, as it can be restored to normal by pretreatment with the functional somatostatin antagonist arginine. The blunted GH release to GHRH may be an early and long lasting sign of autonomous cortisol secretion by the adrenal adenoma.

Ca(2+) transport into an intracellular acidic compartment of Candida parapsilosis.

In this report, we study Ca2+ transport in permeabilized Candida parapsilosis spheroplasts prepared by a new technique using lyticase. An intracellular non-mitochondrial Ca2+ uptake pathway, insensitive to orthovanadate and sensitive to the V-H(+)-ATPase inhibitor bafilomycin A(1), nigericin and carbonyl cyanide p-trifluoromethoxyphenylhydrazone was characterized. Acidification of the compartment in which Ca2+ accumulated was followed using the fluorescent dye acridine orange. Acidification was stimulated by the Ca2+ chelator EGTA and inhibited by Ca2+. These results, when added to the observation that Ca2+ induces alkalization of a cellular compartment, provide evidence for the presence of a Ca2+/nH(+) antiporter in the acid compartment membrane. Interestingly, like in acidocalcisomes of trypanosomatids, the antioxidant 3,5-dibutyl-4-hydroxytoluene inhibits the V-H(+)-ATPase. In addition, the antifungal agent ketoconazole promoted a fast alkalization of the acidic compartment. Ketoconazole effects were dose-dependent and occurred in a concentration range close to that attained in the plasma of patients treated with this drug.

First evidence and characterization of an uncoupling protein in fungi kingdom: CpUCP of Candida parapsilosis.

An uncoupling protein (UCP) was identified in mitochondria from Candida parapsilosis (CpUCP), a non-fermentative parasitic yeast. CpUCP was immunodetected using polyclonal antibodies raised against plant UCP. Activity of CpUCP, investigated in mitochondria depleted of free fatty acids, was stimulated by linoleic acid (LA) and inhibited by GTP. Activity of CpUCP enhanced state 4 respiration by decreasing DeltaPsi and lowered the ADP/O ratio. Thus, it was able to divert energy from oxidative phosphorylation. The voltage dependence of electron flux indicated that LA had a pure protonophoretic effect. The discovery of CpUCP proves that UCP-like proteins occur in the four eukaryotic kingdoms: animals, plants, fungi and protists.

Respiratory chain network in mitochondria of Candida parapsilosis: ADP/O appraisal of the multiple electron pathways.

In this study we demonstrated that mitochondria of Candida parapsilosis contain a constitutive ubiquinol alternative oxidase (AOX) in addition to a classical respiratory chain (CRC) and a parallel respiratory chain (PAR) both terminating by two different cytochrome c oxidases. The C. parapsilosis AOX is characterized by a fungi-type regulation by GMP (as a stimulator) and linoleic acid (as an inhibitor). Inhibitor screening of the respiratory network by the ADP/O ratio and state 3 respiration determinations showed that (i) oxygen can be reduced by the three terminal oxidases through four paths implying one bypass between CRC and PAR and (ii) the sum of CRC, AOX and PAR capacities is higher than the overall respiration (no additivity) and that their engagement could be progressive according to the redox state of ubiquinone, i.e. first cytochrome pathway, then AOX and finally PAR.

Leukotriene B4 and late asthmatic reactions induced by toluene diisocyanate.

We investigated whether leukotriene B4 (LTB4) is released from the lungs of sensitized subjects during asthmatic reactions induced by toluene diisocyanate (TDI). We examined three groups of TDI-sensitized subjects, one after no exposure to TDI, the second 8 h after an exposure to TDI that caused an early asthmatic reaction, and the third 8 h after an exposure to TDI that caused a late asthmatic reaction. We analyzed bronchoalveolar lavage (BAL) fluid by reverse-phase high-performance liquid chromatography and by specific radioimmunoassay. The mean concentration of LTB4 was higher [0.31 +/- 0.09 (SE) ng/ml, range 0.15-0.51] in BAL fluid of sensitized subjects who developed a late asthmatic reaction than in BAL fluid of subjects who developed an early asthmatic reaction (0.05 +/- 0.04 ng/ml, range 0-0.224), and no LTB4 was detectable in the control subjects. We also performed BAL 8 h after TDI exposure on four TDI-sensitized late-dual reactors who were on steroid treatment. In this group of subjects no LTB4 was detectable. These results suggest that LTB4 may be involved in late asthmatic reactions induced by TDI.

Inhibitory effect of galanin on growth hormone release from rat pituitary tumor cells (GH1) in culture.

The growth hormone (GH) releasing effect of GH-releasing hormone (GHRH) and galanin, a 29-amino acid peptide widely distributed in mammalian CNS, was investigated in cultured rat pituitary tumor cells (GH1) as compared to normal rat somatotrophs. GHRH stimulated dose-dependently GH secretion in normal somatotrophs but did not affect GH secretion in GH1 cells. Galanin (1-10 microM) stimulated GH release in a concentration-dependent manner, but with lower potency as compared to GHRH, in normal rat pituitaries but was inhibitory in rat GH1 cells. The results of this study indicate that while galanin has the ability to stimulate GH release from dispersed pituitary cells of normal rats it has potent direct inhibitory effects on GH release from tumor rat cells.

Theophylline serum levels unmodified by postprandial administration of a sustained-release preparation (Teonova).

The authors studied serum theophylline levels after administration of new single-dose capsules: Teonova. Special attention was paid to possible fluctuations of serum theophylline after administration of the drug following a standardized meal. For this purpose a test was carried out on eight male patients with intrinsic asthma. The patients were given a dose able to produce a serum concentration of theophylline of between 10 mcg and 20 mcg at the tenth hour after the administration. This dose was found to be 400 mg (2 tablets of 200 mg) for one patient and 600 mg (2 tablets of 300 mg) for the remaining seven. The capsules of Teonova were administered to each patient for two subsequent days at 07h00. On the first day the patients had their capsules after fasting, and on the second day after a standardized meal. The test proved that Teonova assured a satisfactory serum theophylline level throughout the 24 hours in all patients; food in no way affected the absorption kinetics of the drug. Such features make Teonova suitable for long-term theophylline therapy.

Identification of epithelial cells in bronchoalveolar lavage.

1. Damage to the bronchial epithelium occurs after the inhalation of toxic substances and allergens, and through virus infections and it may lead to increased desquamation of epithelial cells in bronchoalveolar lavage (BAL). 2. In this study we compared two methods of staining the epithelial cells of BAL, the conventional cytochemical May Grunwald-Giemsa stain (MGG) and an immunocytochemical technique using a monoclonal antibody anti-human cytokeratin (CK) detected with APAAP immuno-alkaline phosphatase. BAL was obtained from 13 subjects and the epithelial cells were cytocentrifuged either immediately after collection (fraction A) or after washing (fraction B). 3. Higher percentages of epithelial cells were identified in fraction A with CK (20.0 +/- 5.1%) than in fraction A with MGG (11.2 +/- 2.3%), which recognized only ciliated epithelial cells. In fact a proportion of CK-positive cells (34%) in fraction A were not ciliated. Underestimation of epithelial cells by MGG compared to CK was more pronounced in fraction B (8.0 +/- 2.9% and 22.9 +/- 3.0%, respectively) as there was a relative loss of ciliated CK+ cells after washings. 4. These results suggest that immunocytochemical staining with an anti-cytokeratin monoclonal antibody is more sensitive than using the MGG stain in detecting epithelial cells in BAL.