Non-Gaussian Correlations in the Steady State of Driven-Dissipative Clouds of Two-Level Atoms

We report experimental measurements of the second-order coherence function g^{(2)}(τ) of the light emitted by a laser-driven dense ensemble of ^{87}Rb atoms. We observe a clear departure from the Siegert relation valid for Gaussian chaotic light. Measuring intensity and first-order coherence, we conclude that the violation is not due to the emergence of a coherent field. This indicates that the light obeys non-Gaussian statistics, stemming from non-Gaussian correlations in the atomic medium. More specifically, the steady state of this driven-dissipative many-body system sustains high-order correlations in the absence of first-order coherence. These findings call for new theoretical and experimental explorations to uncover their origin, and they open new perspectives for the realization of non-Gaussian states of light.

Fermionic Correlation Functions from Randomized Measurements in Programmable Atomic Quantum Devices

We provide an efficient randomized measurement protocol to estimate two- and four-point fermionic correlations in ultracold atom experiments. Our approach is based on combining random atomic beam splitter operations, which can be realized with programmable optical landscapes, with high-resolution imaging systems such as quantum gas microscopes. We illustrate our results in the context of the variational quantum eigensolver algorithm for solving quantum chemistry problems.

Erratum: Momentum-Resolved Observation of Thermal and Quantum Depletion in a Bose Gas [Phys. Rev. Lett. 117, 235303 (2016)]

This corrects the article DOI: 10.1103/PhysRevLett.117.235303.

Observation of 1/k^{4}-Tails after Expansion of Bose-Einstein Condensates with Impurities

We measure the momentum density in a Bose-Einstein condensate (BEC) with dilute spin impurities after an expansion in the presence of interactions. We observe tails decaying as 1/k^{4} at large momentum k in the condensate and in the impurity cloud. These algebraic tails originate from the impurity-BEC interaction, but their amplitudes greatly exceed those expected from two-body contact interactions at equilibrium in the trap. Furthermore, in the absence of impurities, such algebraic tails are not found in the BEC density measured after the interaction-driven expansion. These results highlight the key role played by impurities when present, a possibility that had not been considered in our previous work [Chang et al., Phys. Rev. Lett. 117, 235303 (2016)PRLTAO0031-900710.1103/PhysRevLett.117.235303]. Our measurements suggest that these unexpected algebraic tails originate from the nontrivial dynamics of the expansion in the presence of impurity-bath interactions.

Certifying the Adiabatic Preparation of Ultracold Lattice Bosons in the Vicinity of the Mott Transition

We present a joint experimental and theoretical analysis to assess the adiabatic experimental preparation of ultracold bosons in optical lattices aimed at simulating the three-dimensional Bose-Hubbard model. Thermometry of lattice gases is realized from the superfluid to the Mott regime by combining the measurement of three-dimensional momentum-space densities with ab initio quantum Monte Carlo (QMC) calculations of the same quantity. The measured temperatures are in agreement with isentropic lines reconstructed via QMC for the experimental parameters of interest, with a conserved entropy per particle of S/N=0.8(1)k_{B}. In addition, the Fisher information associated with this thermometry method shows that the latter is most accurate in the critical regime close to the Mott transition, as confirmed in the experiment. These results prove that equilibrium states of the Bose-Hubbard model-including those in the quantum-critical regime above the Mott transition-can be adiabatically prepared in cold-atom apparatus.

Hanbury Brown and Twiss Bunching of Phonons and of the Quantum Depletion in an Interacting Bose Gas

We report the realization of a Hanbury Brown and Twiss (HBT)-like experiment with a gas of interacting bosons at low temperatures. The low-temperature regime is reached in a three-dimensional optical lattice and atom-atom correlations are extracted from the detection of individual metastable helium atoms after a long free fall. We observe, in the noncondensed fraction of the gas, a HBT bunching whose properties strongly deviate from the HBT signals expected for noninteracting bosons. In addition, we show that the measured correlations reflect the peculiar quantum statistics of atoms belonging to the quantum depletion and of the Bogoliubov phonons, i.e., of collective excitations of the many-body quantum state. Our results demonstrate that atom-atom correlations provide information about the quantum state of interacting particles, extending the interest of HBT-like experiments beyond the case of noninteracting particles.

From Substrate to Fragments to Inhibitor Active In Vivo against Staphylococcus aureus

Antibiotic resistance is a worldwide threat due to the decreasing supply of new antimicrobials. Novel targets and innovative strategies are urgently needed to generate pathbreaking drug compounds. NAD kinase (NADK) is essential for growth in most bacteria, as it supports critical metabolic pathways. Here, we report the discovery of a new class of antibacterials that targets bacterial NADK. We generated a series of small synthetic adenine derivatives to screen those harboring promising substituents in order to guide efficient fragment linking. This led to NKI1, a new lead compound inhibiting NADK that showed in vitro bactericidal activity against Staphylococcus aureus. In a murine model of infection, NKI1 restricted survival of the bacteria, including methicillin-resistant S. aureus. Collectively, these findings identify bacterial NADK as a potential drug target and NKI1 as a lead compound in the treatment of staphylococcal infections.

Tan's Contact for Trapped Lieb-Liniger Bosons at Finite Temperature

The universal Tan relations connect a variety of microscopic features of many-body quantum systems with two-body contact interactions to a single quantity, called the contact. The latter has become pivotal in the description of quantum gases. We provide a complete characterization of the Tan contact of the harmonically trapped Lieb-Liniger gas for arbitrary interactions and temperature. Combining thermal Bethe ansatz, local-density approximation, and exact quantum Monte Carlo calculations, we show that the contact is a universal function of only two scaling parameters, and determine the scaling function. We find that the temperature dependence of the contact, or equivalently the interaction dependence of the entropy, displays a maximum. The presence of this maximum provides an unequivocal signature of the crossover to the fermionized regime and it is accessible in current experiments.

High intensity focused ultrasound cyclocoagulation in dogs with primary glaucoma: a preliminary study

The objective was to assess the effect of high intensity focused ultrasound (HIFU) on intraocular pressure (IOP) in dogs with primary glaucoma (PG). Seven dogs (13 eyes) presenting with PG as diagnosed by a raised IOP (> 20 mm Hg) associated with consistent gonioscopy and ultrasound biomicroscopy of the ciliary cleft, with no other ocular disease. Patients were divided into 3 groups, corresponding to their pre-operative IOP (group 1 ranging from 21 to 30 mm Hg, group 2 from 31 to 40 and group 3 for 40 and above). Ciliary process sonication was achieved with a probe containing one high-frequency transducer operating at 21 MHz during 5 seconds. Six sites were treated in patients from group 1, 8 in group 2, 10 in group 3, under general anesthesia. Post-operative treatment consisted of systemic meloxicam and topical carbonic anhydrase inhibitors, beta-blockers and prostaglandins analogues. No intraoperative complications were observed. Conjunctival hyperaemia occurred in eyes from group 2 (66%) and 3 (100%). Conjunctival burns were visible in 2 patients from group 3. One patient from group 3 experienced a hypertensive spike during the first hours post-op with associated pain. The hypotensive effect of HIFU was observed in all groups. Normotensive IOP (≤20 mm Hg) was reached in all patients until the last recheck at 6 months post op. Despite the small number of patients included in the study, HIFU appears to be a promising option for the management of PG in dogs.

Quantum Depletion of a Homogeneous Bose-Einstein Condensate

We measure the quantum depletion of an interacting homogeneous Bose-Einstein condensate and confirm the 70-year-old theory of Bogoliubov. The observed condensate depletion is reversibly tunable by changing the strength of the interparticle interactions. Our atomic homogeneous condensate is produced in an optical-box trap, the interactions are tuned via a magnetic Feshbach resonance, and the condensed fraction is determined by momentum-selective two-photon Bragg scattering.

Momentum-Resolved Observation of Thermal and Quantum Depletion in a Bose Gas

We report on the single-atom-resolved measurement of the distribution of momenta ℏk in a weakly interacting Bose gas after a 330 ms time of flight. We investigate it for various temperatures and clearly separate two contributions to the depletion of the condensate by their k dependence. The first one is the thermal depletion. The second contribution falls off as k^{-4}, and its magnitude increases with the in-trap condensate density as predicted by the Bogoliubov theory at zero temperature. These observations suggest associating it with the quantum depletion. How this contribution can survive the expansion of the released interacting condensate is an intriguing open question.

Characterization of a detector chain using a FPGA-based time-to-digital converter to reconstruct the three-dimensional coordinates of single particles at high flux

We report on the development of a novel FPGA-based time-to-digital converter and its implementation in a detection chain that records the coordinates of single particles along three dimensions. The detector is composed of micro-channel plates mounted on top of a cross delay line and connected to fast electronics. We demonstrate continuous recording of the timing signals from the cross delay line at rates up to 4.1 × 10(6) s(-1) and three-dimensional reconstruction of the coordinates up to 3.2 × 10(6) particles per second. From the imaging of a calibrated structure we measure the in-plane resolution of the detector to be 140(20) μm at a flux of 3 × 10(5) particles per second. In addition, we analyze a method to estimate the resolution without placing any structure under vacuum, a significant practical improvement. While we use UV photons here, the results of this work apply to the detection of other kinds of particles.

Influence of gold coating and interplate voltage on the performance of chevron micro-channel plates for temporally and spatially resolved single particle detection

We present a study of two different sets of Micro-Channel Plates used for time and space resolved single particle detection. We investigate the effects of the gold coating and that of introducing an interplate voltage between the spatially separated plates. We find that the gold coating increases the count rate of the detector and the pulse amplitude as previously reported for non-spatially resolved setups. The interplate voltage also increases count rates. In addition, we find that a non-zero interplate voltage improves the spatial accuracy in determining the arrival position of incoming single particles (by ~20%) while the gold coating has a negative effect (by ~30%).

Quasiparticle dynamics in a bose insulator probed by interband bragg spectroscopy

We investigate experimentally and theoretically the dynamical properties of a Mott insulator in decoupled one-dimensional chains. Using a theoretical analysis of the Bragg excitation scheme, we show that the spectrum of interband transitions holds information on the single-particle Green's function of the insulator. In particular, the existence of particle-hole coherence due to quantum fluctuations in the Mott state is clearly seen in the Bragg spectra and quantified. Finally, we propose a scheme to directly measure the full, momentum-resolved spectral function as obtained in the angle-resolved photoemission spectroscopy of solids.

An oscillator circuit to produce a radio-frequency discharge and application to metastable helium saturated absorption spectroscopy

We present a rf gas discharge apparatus which provides an atomic frequency reference for laser manipulation of metastable helium. We discuss the biasing and operation of a Colpitts oscillator in which the discharge coil is part of the oscillator circuit. Radiofrequency radiation is reduced by placing the entire oscillator in a metal enclosure.

Exploring correlated 1D bose gases from the superfluid to the mott-insulator state by inelastic light scattering

We report the Bragg spectroscopy of interacting one-dimensional Bose gases loaded in an optical lattice across the superfluid to the Mott-insulator phase transition. Elementary excitations are created with a nonzero momentum and the response of the correlated 1D gases is in the linear regime. The complexity of the strongly correlated quantum phases is directly displayed in the spectra which exhibit novel features. This work paves the way for a precise characterization of the state of correlated gases in optical lattices.

Anderson localization of Bogolyubov quasiparticles in interacting Bose-Einstein condensates

We study the Anderson localization of Bogolyubov quasiparticles in an interacting Bose-Einstein condensate (with a healing [corrected] length xi) subjected to a random potential (with a finite correlation length sigma(R)). We derive analytically the Lyapunov exponent as a function of the quasiparticle momentum k, and we study the localization maximum k(max). For 1D speckle potentials, we find that k(max) proportional variant 1/xi when xi>>sigma(R) while k(max) proportional variant 1/sigma(R) when xi<<sigma(R), and that the localization is strongest when xi approximately sigma(R). Numerical calculations support our analysis, and our estimates indicate that the localization of the Bogolyubov quasiparticles is accessible in experiments with ultracold atoms.

La myomectomie par cœlioscopie en 2007: état des lieux

With fifteen years of development, laparoscopy for myomectomy has proven its advantages. However, this technique remains controversial concerning its feasibility and the quality of uterine scar obtained. Laparoscopic myomectomy (LM) is usually indicated when number of myomas is less than 3 to 4 with a 8 to 9 cm maximal size. Surgical technique is standardized and intervention time becomes acceptable. Risk of conversion ranges between 1 to 3% when technique is realized by trained surgeon. Bleeding is less important compared with laparotomy and immediate postoperative complications are exceptional. Results concerning fertility are positive with more than 50% of infertile patient conceiving after surgery, this rate rising up to 61 to 76% for myomas isolated cause for infertility; these values can be compared with myomectomy realized by laparotomy. Postoperative adhesions seem to be less important after laparoscopy when compared with laparotomy but this point needs to be confirmed. Risk of uterine rupture is estimated between 0 to 1%, but this point needs for larger series evaluation and needs to be compared with pregnancies after laparotomy. Laparoscopic myomectomy is a feasible technique, safe for patients waiting for conception and has proven its interest in case of infertility.

Anderson localization of expanding Bose-Einstein condensates in random potentials

We show that the expansion of an initially confined interacting 1D Bose-Einstein condensate can exhibit Anderson localization in a weak random potential with correlation length sigma(R). For speckle potentials the Fourier transform of the correlation function vanishes for momenta k>2/sigma(R) so that the Lyapunov exponent vanishes in the Born approximation for k>1/sigma(R). Then, for the initial healing length of the condensate xi(in)>sigma(R) the localization is exponential, and for xi(in)<sigma(R) it changes to algebraic.

Performance of laparoscopy in identifying malignant ovarian cysts

BACKGROUND

Peroperative identification of malignancy is crucial to management planning for ovarian cysts. The aim of this study was to evaluate the performance of laparoscopy in identifying malignant ovarian cysts.

METHODS

Patients undergoing laparoscopy for ovarian cysts from 1998 to 2001 were enrolled prospectively. Physical findings, Doppler ultrasonography, and serum CA 125 served to compute two risk-of-malignancy indexes (RMI-1 and RMI-2), and laparoscopy findings served to categorize lesions as benign, possibly malignant, or malignant. Frozen sections were examined as needed. Final histology was the reference.

RESULTS

Of 313 patients, 294 had benign cysts, six borderline lesions, and 13 malignancies. Sensitivity and specificity were respectively 84 and 93% for RMI-1, 92 and 80% for RMI-2, 100 and 99% for laparoscopy, 91 and 100% for frozen sections, and 100 and 100% for laparoscopy plus frozen sections, which had 100% negative predictive value. Six (1.8%) adverse events occurred.

CONCLUSIONS

Laparoscopy reliably identifies ovarian cancer and borderline disease. Morbidity is low compared to oncologic surgery.

[Is sentinel node biopsy feasible in endometrial cancer? Results in 26 patients]

OBJECTIVES

To evaluate detection rate, topography and false negatives of sentinel lymph node in endometrial cancer.

MATERIAL AND METHODS

Twenty-six patients were included. Lymphoscintigraphy was performed the day before surgery. Preoperative detection of the sentinel lymph node was performed with cervical blue dye injection and a gamma probe. Separate pathology examinations were performed for sentinel and non-sentinel lymph nodes. Sentinel lymph nodes were examined with hematoxylin-eosin-safran stain, and immunohistochemistry if negative.

RESULTS

Twenty-six patients had a positive lymphoscintigraphy. Preoperative detection was successful in 21 patients (80.8%): the detection rate with isotopic method, 19 cases (73.1%), was superior to the dye detection, 15 cases (57.7%). No isolated lombo-aortic sentinel lymph nodes were observed, and all sentinel lymph nodes were in the ilio-obturator region. Seven patients presented lymphatic spread, and 4 of them had at least one sentinel node. There was one micrometastasis in sentinel node, associated with isolated tumoral cells in pelvic lymphadenectomy. There was no false negative of sentinel node.

CONCLUSION

The biopsy of sentinel lymph node is a feasible procedure in endometrial cancer. There was one micrometastatic sentinel node. However there was no isolated lomboaortic sentinel lymph node in this study.

Sentinel node biopsy helps to diagnose spread of endometrial cancer. A case report

BACKGROUND

The sentinel lymph node (SLN) could improve the staging of endometrial cancer.

CASE

In a patient with endometrial cancer, preoperative lymphoscintigraphy showed a highly radioactive SLN in the left external iliac chain and a radioactive SLN in the right external iliac chain and at the promontory. Intraoperative lymphatic mapping using blue dye and a hand-held gamma probe showed the same nodes, as well as a blue node near the vena cava. Selective removal of these nodes allowed detection of a micrometastasis in the left external iliac node. Pelvic node dissection was performed, and a micrometastasis was found in a left non sentinel iliac node.

CONCLUSION

The presence in our patient of micrometastases in a SLN and in a non-SLN belonging to the same chain confirms the value of SLN detection for diagnosing tumor spread.

Suppression of transport of an interacting elongated Bose-Einstein condensate in a random potential

We observe the suppression of the 1D transport of an interacting elongated Bose-Einstein condensate in a random potential with an amplitude that is small compared to the typical energy per atom, dominated by the interaction energy. Numerical calculations reproduce our observations well. We propose a scenario for disorder-induced trapping of the condensate in agreement with our findings.

Creation of BAC genomic resources for cocoa ( Theobroma cacao L.) for physical mapping of RGA containing BAC clones

We have constructed and validated the first cocoa ( Theobroma cacao L.) BAC library, with the aim of developing molecular resources to study the structure and evolution of the genome of this perennial crop. This library contains 36,864 clones with an average insert size of 120 kb, representing approximately ten haploid genome equivalents. It was constructed from the genotype Scavina-6 (Sca-6), a Forastero clone highly resistant to cocoa pathogens and a parent of existing mapping populations. Validation of the BAC library was carried out with a set of 13 genetically-anchored single copy and one duplicated markers. An average of nine BAC clones per probe was identified, giving an initial experimental estimation of the genome coverage represented in the library. Screening of the library with a set of resistance gene analogues (RGAs), previously mapped in cocoa and co-localizing with QTL for resistance to Phytophthora traits, confirmed at the physical level the tight clustering of RGAs in the cocoa genome and provided the first insights into the relationships between genetic and physical distances in the cocoa genome. This library represents an available BAC resource for structural genomic studies or map-based cloning of genes corresponding to important QTLs for agronomic traits such as resistance genes to major cocoa pathogens like Phytophthora spp ( palmivora and megakarya), Crinipellis perniciosa and Moniliophthora roreri.

Chemical peritonitis: a rare complication of an iatrogenic ovarian dermoid cyst rupture

Laparoscopy is the standard method for the diagnosis and treatment of ovarian dermoid cysts, which represent 10% to 15% of all ovarian tumors. This procedure offers many advantages including less postoperative pain, lower risk of wound complication, early ambulation, and more rapid convalescence. The risk of adhesion formation also is reduced. However, in the case of an ovarian dermoid cyst, the laparoscopic approach could result in chemical peritonitis caused by the spilled contents of a ruptured dermoid cyst. We report a case of chemical peritonitis after rupture of an ovarian dermoid cyst during laparoscopy. Two operations were required, and medical treatment was not beneficial. We discuss a possible new medication for the treatment of this complication and compare this case with other recent reports.

Findings of the Naftidrofuryl in Quality of Life (NIQOL) European study program

BACKGROUND

We report in this paper the findings of a pooled analysis of 3 previously published studies undertaken in Germany, France and Belgium to assess the effects of naftidrofuryl on the quality of life of patients with intermittent claudication.

METHODS

A total of 754 patients were randomised in the 3 studies, 709 of whom (358 naftidrofuryl, 351 placebo) were available for the primary intention-to-treat analysis. The primary outcome variable was the change in the disease-related limitation of the quality of life as measured by the CLAU-S questionnaire. This instrument which has been validated in an international study, comprises 47 questions covering 5 dimensions: "daily living", "pain", "social life", "disease specific anxiety" and "mood".

RESULTS

A multivariate analysis of covariance adjusted for baseline values, study effect and first order study treatment interaction, demonstrated the global superiority of naftidrofuryl over placebo (p<0.001). A separate covariance analysis for the 5 dimensions showed highly significant differences for "daily living", "pain", "social life" and "mood" (all p<0.01).

CONCLUSIONS

In conclusion, this pooled analysis has shown that naftidrofuryl can significantly improve the quality of life of patients with intermittent claudication. These findings, taken together with evidence from previous studies that it improves treadmill walking distances, suggest that naftidrofuryl can play a useful role in the treatment of this condition.

Genetic mapping of resistance factors to Phytophthora palmivora in cocoa

Phytophthora palmivora causes pod rot, a serious disease on cocoa widespread throughout the producing regions. In order to ascertain the genetic determination of cocoa resistance to P. palmivora, a study was carried out on two progenies derived from crosses between a heterozygous, moderately resistant Forastero clone, T60/887, and two closely related and highly susceptible Forastero clones, one completely homozygous, IFC2, and one partially heterozygous, IFC5. The cumulative size of both progenies was 112 individuals. Plants were subjected to natural and artificial inoculation of P. palmivora in Côte d'Ivoire. The genetic maps of T60/887 and of IFC5 were constructed using amplified fragment length polymorphism (AFLP) markers and microsatellites. The map of T60/887 comprised 198 markers assembled in 11 linkage groups and representing a total length of 793 cM. The map of IFC5 comprised 55 AFLP markers that were assembled into six linkage groups for a total length of 244 cM. Ratio of rotten over total number of fruit under natural infection was measured for each tree over two harvests. Artificial inoculations were performed on leaves and pods. These tests were weakly correlated with the pod rot rate in the field. Five quantitative trait loci (QTLs) of resistance were detected for T60/887 but none were common between the three traits measured. Stability and reliability of the experimental procedures are discussed and revealed the difficult use of these artificial tests on adult trees for a good prediction of field resistance.Key words: Theobroma cacao, Phytophthora palmivora, cocoa black pod disease, genetic map, quantitative trait locus (QTL).

Genetic mapping of resistance factors to Phytophthora palmivora in cocoa

Phytophthora palmivora causes pod rot, a serious disease on cocoa widespread throughout the producing regions. In order to ascertain the genetic determination of cocoa resistance to P. palmivora, a study was carried out on two progenies derived from crosses between a heterozygous, moderately resistant Forastero clone, T60/887, and two closely related and highly susceptible Forastero clones, one completely homozygous, IFC2, and one partially heterozygous, IFC5. The cumulative size of both progenies was 112 individuals. Plants were subjected to natural and artificial inoculation of P. palmivora in C te d'Ivoire. The genetic maps of T60/887 and of IFC5 were constructed using amplified fragment length polymorphism (AFLP) markers and microsatellites. The map of T60/887 comprised 198 markers assembled in 11 linkage groups and representing a total length of 793 cM. The map of IFC5 comprised 55 AFLP markers that were assembled into six linkage groups for a total length of 244 cM. Ratio of rotten over total number of fruit under natural infection was measured for each tree over two harvests. Artificial inoculations were performed on leaves and pods. These tests were weakly correlated with the pod rot rate in the field. Five quantitative trait loci (QTLs) of resistance were detected for T60/887 but none were common between the three traits measured. Stability and reliability of the experimental procedures are discussed and revealed the difficult use of these artificial tests on adult trees for a good prediction of field resistance.

Cellular biocompatibility and resistance to compression of macroporous beta-tricalcium phosphate ceramics

The main problem for macroporous structures used as bone substitutes is their lower resistances when compared to that of cancellous bone. The present investigation aimed to improve the strength of ceramics with 65% porosities based on beta-TCP. The initial mixtures were rendered plastic by addition of non-ionic carbohydrate binders. Macropores were created using substances which were eliminated by heat. Mechanical tests indicated that the resistance of the ceramics depended more on the quantity than the nature of the binders. Porosity measurements were done with a mercury porosimeter, and cellular biocompatibility was evaluated by performing cellular attachment tests and observing the proliferation of differentiated cells.

Evolution of the local calcium content around irradiated beta-tricalcium phosphate ceramic implants: in vivo study in the rabbit

To evaluate whether dissolved calcium from tricalcium phosphate implants contributes to osseous wound healing in bone defects, the authors used nuclear radioactivated materials. Six months after irradiation, the calcium was still radioactive. Samples of the material were prepared and placed in rabbit condyles for 1, 3 and 9 months. Over time the condyles were retrieved and treated for histology or radiocounting. Measurements of the radioactivity of the slices and histomorphometry of the implants and surrounding tissues were performed. The authors observed that the radioactivity decreased regularly. Connective tissue had penetrated the pores and totally invaded the implants, first at the periphery of the implants, then inside the pores. Comparison of the results of radioactivity and histomorphometry suggest that part of the calcium from the implants was re-used specifically in the new osseous tissue.

Anti-human cytomegalovirus activity of cytokines produced by CD4+ T-cell clones specifically activated by IE1 peptides in vitro

The control of latent cytomegalovirus (CMV) infections by the immune system is poorly understood. We have previously shown that CD4+ T cells specific for the human CMV major regulatory protein IE1 are frequent in latently infected healthy blood donors. In order to learn about the possible role of these cells, we have developed IE1-specific CD4+ T-cell clones and, in this study, analyzed their epitope specificity and function in vitro. We measured their cytokine production when stimulated with specific IE1 peptides or whole recombinant IE1 protein. Their cytokine profiles, as deduced from gamma interferon (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), and interleukin-4 (IL-4) and IL-6 production, were of the Th0- and Th1-like phenotypes. Supernatants from IE1-specific clones producing IFN-gamma and TNF-alpha were shown to inhibit CMV replication in U373 MG cells. This effect was due, as found by using cytokine-specific neutralizing antibodies, mostly to IFN-gamma, which was secreted at higher levels than TNF-alpha. To better assess the anti-CMV activity of cytokines, recombinant IFN-gamma and TNF-alpha were used and shown to have a synergistic effect on the inhibition of CMV replication and protein expression. Thus, IE1-specific CD4+ T cells display in vitro anti-CMV activity through cytokine secretion and may play a role in the control of in vivo latent infections.

Analysis of the proliferative T cell response to human cytomegalovirus major immediate-early protein (IE1): phenotype, frequency and variability

Cellular immune responses are important in the recovery from human cytomegalovirus (HCMV) infection. However, little is known about the CD4+ T cell response and the target antigens (Ag) recognized. In this paper, we have analysed the proliferative T cell response of healthy HCMV seropositive (HCMV+) blood donors to recombinant immediate-early proteins expressed in transfected astrocytoma cells and to total HCMV Ags expressed in infected astrocytoma cells. We found that CD4+ T cells were the major cell population that proliferated in the presence of IE or total HCMV Ags. Among healthy HCMV seropositive blood donors with anti-HCMV specific proliferative response, 33-44% also responded to IE Ags. Moreover, in high responders, the precursor frequencies of cells which proliferated in the presence of total HCMV, IE, or IE1 Ags were high (1/103 to 1/255, 1/2785 to 1/7744 and 1/5190 to 1/13531, respectively). In some donors, the anti-IE response was variable over time, whereas the anti-total HCMV Ags response remained constant, which suggests regulation of the anti-IE response in immunocompetent subjects. Our results suggest that the CD4+ anti-IE1 response represents a significant part of the anti-HCMV proliferative response, both at the population level, and within individual immune systems.

Expression of human cytomegalovirus immediate early protein IE1 in insect cells: splicing of RNA and recognition by CD4+ T-cell clones

Recombinant baculoviruses containing the unspliced gene (Bac-IE1) and a truncated cDNA (Bac-EX4) of the immediate early protein 1 (IE1) of human cytomegalovirus (HCMV) were constructed. The recombinant proteins IE1 and EX4 were expressed in Sf 9 insect cells. Immunoblot analyses using a specific monoclonal antibody or human sera from HCMV seropositive subjects revealed that the IE1 protein had an apparent molecular mass of 71 kDa which was similar to that observed in both HCMV infected human fibroblasts and infected or transfected human astrocytoma cells. Furthermore, HCMV-specific CD4+ T cell clones proliferated in the presence of IE1 or of EX4 used as a control, and appropriate antigen presenting cells. Our data on the IE1 gene provide evidence that two introns can be properly spliced out in baculovirus infected insect cells. The expressed proteins should be useful in further studies on the immune response to the virus.

Prognostic significance of karyotype in a twelve-year follow-up in childhood acute lymphoblastic leukemia

We report a follow-up of 49 children with acute lymphoblastic leukemia (ALL) diagnosed between 1972 and 1978 (follow-up 12-18 years). This series allowed us to analyze the predictive value of karyotype in a long-term follow-up. Karyotypes were abnormal in 33 cases (67.3%): pseudodiploidy in 11 (22.4%), hyperdiploidy > 50 chromosomes in 8 (16.3%), hyperdiploidy 47-50 chromosomes in 11 (22.4%), and hypodiploidy in 3 cases (6.1%). Event-free survival (EFS) and survival studies showed that the outcome of patients was determined only by treatment and karyotype. Eleven patients have survived, nine in first remission (6 years 5 months to 15 years 2 months), and two are in second remission (3 years 8 months and 8 years 2 months). All ploidy groups are represented in these patients. Late relapses can occur in the hyperdiploid > 50 group, thus accounting for shorter EFS than expected, but because of the unusually long second remission of one patient, the rate of surviving patients was higher for this ploidy group than for all other ploidy groups together. Conversely, patients with only numerical abnormalities (no matter which ploidy group they belonged to), had a better outcome than did patients with structural changes or normal karyotypes and no discrepancy between EFS and survival curves was observed in this chromosomal group. Thus, our results suggest that numerical changes only should be considered an indicator of low risk factor, but our results, based on partially banded karyotypes, need to be verified by a current method and therapy.

Syst-Eur. A multicentre trial on the treatment of isolated systolic hypertension in the elderly: objectives, protocol, and organization

The Syst-Eur Trial is a concerted action of the European Community's Medical and Health Research Programme. The trial is carried out in consultation with the World Health Organization, the International Society of Hypertension, the European Society of Hypertension and the World Hypertension League. This article describes the objectives and the protocol of Syst-Eur, a multicentre trial designed by the European Working Party on High Blood Pressure in the Elderly (EWPHE), to test the hypothesis that antihypertensive treatment of elderly patients with isolated systolic hypertension results in a significant change in stroke morbidity and mortality. Secondary endpoints include cardiovascular events, such as myocardial infarction and congestive heart failure. To be eligible patients must be at least 60 years old and have a systolic blood pressure averaging 160-219 mmHg with a diastolic pressure less than 95 mmHg. Patients must give their informed consent and be free of major cardiovascular and non-cardiovascular diseases at entry. The patients are randomized to active treatment or placebo. Active treatment consists of nitrendipine (10-40 mg/day), combined with enalapril (5-20 mg/day) and hydrochlorothiazide (12.5-25 mg/day), as necessary. The patients of the control group receive matching placebos. The drugs (or matching placebos) are stepwise titrated and combined in order to reduce systolic blood pressure by 20 mmHg at least to a level below 150 mmHg. Morbidity and mortality are monitored to enable an intention-to-treat and per-protocol comparison of the outcome in the 2 treatment groups. A one-year pilot trial (1989) showed that the protocol is practicable. The Ethics Committee therefore decided to start the definite study (1990), in which randomized patients will be followed for 5 years. Recruitment of new centres and of the required 3,000 patients will last 3 years (until 1993).