Influence of preoperative life satisfaction on recovery and outcomes after colorectal cancer surgery - a prospective pilot study.

BACKGROUND: Colorectal surgery has an important impact on a patient's quality of life, and postoperative rehabilitation shows large variations. To enhance the understanding of recovery after colorectal cancer, health-related quality of life has become a standard outcome measurement for clinical care and research. Therefore, we aimed to correlate the influence of preoperative global life satisfaction on subjective feelings of well-being with clinical outcomes after colorectal surgery. METHODS: In this pilot study of consecutive colorectal surgery patients, various dimensions of feelings of preoperative life satisfaction were assessed using a self-rated scale, which was validated in French. Both objective (length of stay and complications) and subjective (pain, subjective well-being and quality of sleep) indicators of recovery were evaluated daily during each patient's hospital stay. RESULTS: A total of 112 patients were included. The results showed a negative relationship between life satisfaction and postoperative complications and a significant negative correlation with the length of stay. Moreover, a significant positive correlation between life satisfaction and the combined subjective indicators of recovery was observed. CONCLUSION: We have shown the importance of positive preoperative mental states and global life satisfaction as characteristics that are associated with an improved recovery after colorectal surgery. Therefore, patients with a good level of life satisfaction may be better able to face the consequences of colorectal surgery, which is a relevant parameter in supportive cancer care.

Limitations in ionization-induced compression of femtosecond laser pulses due to spatio-temporal couplings.

It was recently proposed that ionization-induced self-compression could be used as an effective method to further compress femtosecond laser pulses propagating freely in a gas jet [He et al., Phys. Rev. Lett. 113, 263904 2014]. Here, we address the question of the homogeneity of the self-compression process and show experimentally that homogeneous self-compression down to 12fs can be obtained by finding the appropriate focusing geometry for the laser pulse. Simulations are used to reproduce the experimental results and give insight into the self-compression process and its limitations. Simulations suggest that the ionization process induces spatio-temporal couplings which lengthen the pulse duration at focus, possibly making this method ineffective for increasing the laser peak intensity.

Spectral phase measurement of a Fano resonance using tunable attosecond pulses.

Electron dynamics induced by resonant absorption of light is of fundamental importance in nature and has been the subject of countless studies in many scientific areas. Above the ionization threshold of atomic or molecular systems, the presence of discrete states leads to autoionization, which is an interference between two quantum paths: direct ionization and excitation of the discrete state coupled to the continuum. Traditionally studied with synchrotron radiation, the probability for autoionization exhibits a universal Fano intensity profile as a function of excitation energy. However, without additional phase information, the full temporal dynamics cannot be recovered. Here we use tunable attosecond pulses combined with weak infrared radiation in an interferometric setup to measure not only the intensity but also the phase variation of the photoionization amplitude across an autoionization resonance in argon. The phase variation can be used as a fingerprint of the interactions between the discrete state and the ionization continua, indicating a new route towards monitoring electron correlations in time.

KRAS and BRAF mutations are prognostic biomarkers in patients undergoing lung metastasectomy of colorectal cancer.

BACKGROUND: We evaluated KRAS (mKRAS (mutant KRAS)) and BRAF (mBRAF (mutant BRAF)) mutations to determine their prognostic potential in assessing patients with colorectal cancer (CRC) for lung metastasectomy. METHODS: Data were reviewed from 180 patients with a diagnosis of CRC who underwent a lung metastasectomy between January 1998 and December 2011. RESULTS: Molecular analysis revealed mKRAS in 93 patients (51.7%), mBRAF in 19 patients (10.6%). In univariate analyses, overall survival (OS) was influenced by thoracic nodal status (median OS: 98 months for pN-, 27 months for pN+, P<0.0001), multiple thoracic metastases (75 months vs 101 months, P=0.008) or a history of liver metastases (94 months vs 101 months, P=0.04). mBRAF had a significantly worse OS than mKRAS and wild type (WT) (P<0.0001). The 5-year OS was 0% for mBRAF, 44% for mKRAS and 100% for WT, with corresponding median OS of 15, 55 and 98 months, respectively (P<0.0001). In multivariate analysis, WT BRAF (HR: 0.005 (95% CI: 0.001-0.02), P<0.0001) and WT KRAS (HR: 0.04 (95% CI: 0.02-0.1), P<0.0001) had a significant impact on OS. CONCLUSIONS: mKRAS and mBRAF seem to be prognostic factors in patients with CRC who undergo lung metastasectomy. Further studies are necessary.

Attosecond pulse walk-off in high-order harmonic generation.

We study the influence of the generation conditions on the group delay of attosecond pulses in high-order harmonic generation in gases. The group delay relative to the fundamental field is found to decrease with increasing gas pressure in the generation cell, reflecting a temporal walk-off due to the dispersive properties of the nonlinear medium. This effect is well reproduced using an on-axis phase-matching model of high-order harmonic generation in an absorbing gas.

Probing single-photon ionization on the attosecond time scale.

We study photoionization of argon atoms excited by attosecond pulses using an interferometric measurement technique. We measure the difference in time delays between electrons emitted from the 3s(2) and from the 3p(6) shell, at different excitation energies ranging from 32 to 42 eV. The determination of photoemission time delays requires taking into account the measurement process, involving the interaction with a probing infrared field. This contribution can be estimated using a universal formula and is found to account for a substantial fraction of the measured delay.

Control of the attosecond synchronization of XUV radiation with phase-optimized mirrors.

We report on the advanced amplitude and phase control of attosecond radiation allowed by specifically-designed multilayer XUV mirrors. We first demonstrate that such mirrors can compensate for the intrinsic chirp of the attosecond emission over a large bandwidth of more than 20 eV. We then show that their combination with metallic foils introduces a third-order dispersion that is adjustable through the mirror's incidence angle. This results in a controllable beating allowing the radiation to be shaped from a single to a series of sub-100 as pulses.

Noninvasive vibrational mode spectroscopy of ion Coulomb crystals through resonant collective coupling to an optical cavity field.

We report on a novel noninvasive method to determine the normal mode frequencies of ion Coulomb crystals in traps based on the resonance enhanced collective coupling between the electronic states of the ions and an optical cavity field at the single photon level. Excitations of the normal modes are observed through a Doppler broadening of the resonance. An excellent agreement with the predictions of a zero-temperature uniformly charged liquid plasma model is found. The technique opens up for investigations of the heating and damping of cold plasma modes, as well as the coupling between them.

Primary tumour genetic alterations and intra-tumoral heterogeneity are maintained in xenografts of human colon cancers showing chromosome instability.

Evaluation of the role of clonal heterogeneity in colon tumour sensitivity/resistance to drugs and/or in conferring metastatic potential requires an adequate experimental model in which the tumour cells maintain the initial genetic alterations and intra-tumoral heterogeneity through maintenance of the genetic clones present in the initial tumour. Therefore, we xenografted subcutaneously into nude mice seven human colonic tumours (from stages B1 to D) that showed chromosome instability and transplanted them sequentially for up to 14 passages. Maintenance after xenografting of the genetic alterations present in the initial tumours was scored by allelotype studies targeting 45 loci localized on 18 chromosomes. We show that xenografting does not alter the genetic or the histological profiles of the tumours even after 14 passages. Screening of the entire genome of one tumour by comparative genome hybridization also showed overall stability of the alterations between the initial and the xenografted tumour. In addition, intra-tumoral heterogeneity was maintained over time, suggesting that no clonal selection occurred in the nude mice. The observation that some loci showed partial allelic imbalance in the initial tumour but loss of heterozygosity after the first passage in nude mice when all the normal cells were lost may allow identification of interesting genetic defects that could be involved in tumour expansion. Thus, sequential xenografts of colon tumours will provide a powerful model for further study of tumour clonality and for the identification of genetic profiles responsible for differential resistance to therapeutic treatments. Our data also suggest that tumour expansion can result from alterations in several distinct genetic pathways.

Oxytocin receptor gene expression in rat mammary gland: structural characterization and regulation.

The differential, tissue-specific regulation of oxytocin (OT) binding sites allows the neurohypophysial nonapeptide OT to fulfill a dual role: to induce uterine contractions at parturition and to mediate milk ejection during lactation. Whereas uterine OT binding sites are up-regulated prior to parturition and are rapidly down-regulated thereafter, mammary gland OT binding sites gradually increase throughout gestation and remain up-regulated during the ensuing lactation period. Here, we structurally characterized OT receptor (OTR) mRNA in mammary gland and analyzed its expression during gestation and lactation and in response to steroid treatment. In mammary gland tissues, we found a 6.7 and a 5.4 kb OTR mRNA species, and both species were further analyzed by RACE (rapid amplification of cDNA ends). The 6.7 kb mRNA was found to be common to mammary gland and uterus and to extend 618 nucleotides beyond the published sequence of the rat OTR gene. The 5.4 kb mRNA species is unique to the mammary gland and terminates at a mammary gland-specific polyadenylation site that is not preceded by a classical polyadenylation signal. RT-PCR analysis did not provide any evidence for differences in the coding regions, suggesting that both uterine and mammary gland OTR mRNAs encode the same receptor protein. Furthermore, primer extension experiments showed that no differences exist in the specific transcriptional initiation sites of the OTR gene in the two tissues. During pregnancy, OTR mRNA per mammary gland increased approximately 150-fold and remained high during lactation, consistent with the previously identified regulation of OT binding sites and the role of OT during lactation. Whereas estrogen administration strongly induced the uterine OTR mRNA levels (>5-fold), mammary gland remained unaffected by steroid treatment. Moreover, tamoxifen had no effect on the mammary gland OTR mRNA level. In summary, our data demonstrate a differential control of OTR expression in uterus versus mammary gland and a mammary gland-specific OTR mRNA polyadenylation site. However, this differential control apparently does not involve the expression of different receptor genes nor the utilization of tissue-specific transcriptional initiation sites.

Pharmacological characterization of oxytocin-binding sites in rat spinal cord membranes: comparison with embryonic cultured spinal cord neurones and astrocytes.

Detection and pharmacological characterization of OT-binding sites were performed on 12-day-old rat spinal cord membranes and on embryonic cultured spinal neurones and astrocytes after 12 days in culture. In neurone-enriched cultures, OT-binding sites were detected by autoradiography on cells morphologically comparable to neurone-specific enolase immunoreactive cells. In astrocyte cultures, as shown by combination of autoradiography and immunocytochemistry, OT-binding sites were detected on cells expressing the glial fibrillary acidic protein (a specific astrocytic marker). The pharmacological characterization was assessed by binding studies performed with a highly specific radioiodinated OT antagonist on postnatal rat spinal cord membranes and on embryonic cultured spinal cord neurones and astrocytes. The saturation studies suggested the presence of a single class of binding sites of high affinity for the OT antagonist on spinal membranes and cultured cells, as already described in the rat for central and peripheric OT receptors. The competition studies indicated that on spinal membranes, OT and AVP had the same high affinity, as classically described, whereas on cultured cells, AVP had a lower affinity, suggesting that culture conditions may influence the pharmacology of the spinal OT-binding sites. Involvement of NEM- and Gpp[NH]p-insensitive G-proteins in the coupling of the spinal OT-binding sites with the effector system was evidenced on 12-day-old rat spinal membrane preparations and on neurone and astrocyte cultures.

Downregulation of the oxytocin receptor on cultured astroglial cells.

Cultured astroglial cells obtained from rat fetal hypothalamus express oxytocin (OT) receptors, which have been previously characterized (Di Scala-Guenot and Strosser. Biochem. J. 284: 491-497, 1992), with a radioiodinated OT antagonist. In these cells, at steady-state binding at 37 degrees C, ice-cold acidic treatment released 10% of the bound ligand; with pronase treatment, 52% of the tracer was released. Because the binding was performed with an antagonist, one could assume that the radiolabeled ligand remains locked into the membrane in a state insensitive to the stripping agents rather than being internalized. Receptor downregulation induced by OT was concentration- and time-dependent, leading to a 72% loss of maximal binding capacity without changing the affinity of the receptor. On removal of OT the binding capacity recovered partially and the restoration process was blocked by monensin (20 microM) but not by cycloheximide (20 micrograms/ml), suggesting involvement of receptor recycling. Concerning the early mechanisms involved in the downregulation processes, uncoupling of the receptor from the G protein and the receptor phosphorylation by protein kinase C could be demonstrated. Treatment of the cells with the OT antagonist d(CH2)5OVT was shown to facilitate radioligand binding and to protect the receptor against OT-induced downregulation.

Increase of intracellular calcium induced by oxytocin in hypothalamic cultured astrocytes.

A recent study demonstrated oxytocin (OT) receptors on hypothalamic cultured astrocytes (Di Scala-Guenot and Strosser, 1992). The attempt in the present paper was to determine a possible intracellular calcium mobilization induced by OT receptor activation in these cells. Using the microspectrofluorimetric technique with fura-2, as calcium indicator, brief applications of OT on single astrocytes induced a transient and reversible dose-dependent increase of intracellular calcium concentration ([Ca2+]i) in most of the cells tested. In a few cells, OT application triggered intracellular calcium oscillations. Repetitive applications of OT generally produced a decreasing calcium signal, suggesting a desensitization of the receptor. OT-induced calcium release was prevented by a prior or simultaneous application of an OT antagonist. The origin of the calcium mobilization was assessed during conditions where no extracellular calcium was available. Neither removal of extracellular calcium nor addition of a calcium channel blocker, cadmium 100 microM, in the bathing solution, did affect the calcium response to OT, demonstrating that release of intracellular calcium is solely involved in the OT-induced [Ca2+]i increase. The OT-induced calcium mobilization was abolished after thapsigargin application (100 nM). This indicates that the calcium response to OT application was principally associated with activation of the IP3-sensitive calcium stores. Taken together these results demonstrate that OT receptors previously detected on hypothalamic cultured astrocytes are functional receptors which transduction pathways involve calcium mobilization from IP3-sensitive stores.

Oxytocin receptors on cultured astroglial cells. Kinetic and pharmacological characterization of oxytocin-binding sites on intact hypothalamic and hippocampic cells from foetal rat brain.

The ability of astroglial cells to exhibit oxytocin (OT)-binding sites has been investigated in embryonic hypothalamic and hippocampic astroglial cell cultures. The differential characteristics of binding of OT and [Arg8]vasopressin (AVP) agonists and antagonists to the OT-binding sites using the highly selective iodinated OT antagonist d(CH2)5-[Tyr(Me)2,Thr4,Tyr-NH2(9)]OVT ([125I]OTA) have been evaluated using intact cells maintained for 12 days in culture. The specific binding displayed features of reversibility. Computer analysis of the saturation studies using the LIGAND program indicated that, at 4 degrees C, the antagonist binds to a homogeneous population of sites with a Kd value of 0.02 nM and a low binding-site density of around 2 fmol/dish for hypothalamic cells and 6 fmol/dish for hippocampic cells. For hypothalamic cells, competition curves using unlabelled OT, AVP or V2 AVP agonist were characterized by a pseudo-Hill coefficient below unity (0.7), indicating possible heterogeneity among the binding sites. On the other hand, the dose-inhibition curves resulting from competition studies with hippocampic cells had a pseudo-Hill coefficient close to unity, except for OT. Computer analysis (LIGAND) indicated that the OT dose-inhibition curve was significantly better fitted to a two-site model, and this can be explained by two apparent forms of the receptor having high and low affinities for the displacing drug. The relative potencies of the peptides tested for binding to the high-affinity site were: AVP greater than OT greater than V1 AVP antagonist ([d(CH2)5-Tyr(Me)2]AVP) = V2 AVP agonist greater than AVP-Sar ([d(CH2)5-Sar7,Arg8]VP) in hypothalamic cultures, and OT = AVP greater than V1 AVP antagonist greater than V2 AVP agonist in hippocampic cultures. In addition, autoradiography allowed visualization of OT-binding sites, which are located on both soma and processes of astrocyte-like type of cells. In conclusion, these data provide evidence that glial cell cultures contain specific OT-binding sites which display pharmacological characteristics different from those already reported in neuronal cultures and in the adult rat brain.

Oxytocin receptors on cultured astroglial cells. Regulation by a guanine-nucleotide-binding protein and effect of Mg2+.

Specific binding sites for the radio-iodinated oxytocin (OT) antagonist d(CH2)5-[Tyr(Me)2,Thr4, Tyr-NH2(9)]OVT ([125I]OTA) have been characterized on cultured hypothalamic astroglial cell membranes. The rate of association of the ligand to OT-binding sites was identical in the presence and the absence of the non-hydrolysable GTP analogue guanosine 5'-[beta gamma-imido]triphosphate (Gpp[NH]p, 0.1 mM), whereas the monophasic dissociation reaction became biphasic in the presence of Gpp[NH]p. Scatchard analysis of equilibrium binding of [125I]OTA resulted in a linear plot with a single class of binding sites (Kd 0.06 nM) which were insensitive to the addition of Gpp[NH]p. Unlabelled OT and [Arg8]vasopressin (AVP) bound to high- (H) and low- (L) affinity states with a dissociation constant ratio (KL/KH) of 100 for both hormones. Binding with both high and low affinity required the presence of Mg2+ in the incubation buffer, and the addition of Gpp[NH]p decreased the KL/KH ratio to 10 and increased the percentage of low-affinity binding sites. On the other hand, neither omission of Mg2+ from the buffer nor the addition of Gpp[NH]p altered the binding of either OT or V1 AVP antagonists to OT receptors. In the presence of a G-protein inactivator (N-ethylmaleimide; 3 mM) during OT competition studies the affinities of the two OT-binding sites were unchanged, but 90% of the high-affinity binding sites were converted into the low-affinity state. These results obtained with cultured hypothalamic astroglial cells provide further evidence for a coupling of OT receptors with a guanine-nucleotide-binding protein, with a requirement for Mg2+.

Evidence for the presence of guanylate cyclase-coupled receptors for atrial natriuretic peptide on pituicytes of the neurohypophysis.

The aims of the present study were to determine whether natriuretic peptide receptors coupled to guanylate cyclase are present in the neural lobe (NL) of the pituitary and eventually localized on pituicytes and/or on nerve fibers and whether cyclic GMP may be involved in the regulation of vasopressin secretion. Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) enhanced cyclic GMP content of NLs in a dose-related fashion, with ED(50) values of about 5 x 10(-8)M, while CNP failed to significantly elevate guanylate cyclase activity. ANP stimulated cyclic GMP accumulation in NLs lacking functional nerve fibers, while it was without significant effect on isolated nerve terminals. In the brain, ANP-enhanced cyclic GMP production was similarly expressed in glial and not in neuronal cultures, although intracellular guanylate cyclase activity (stimulated by sodium nitroprusside) was present in both cell types. Finally, the cell permeant S-bromoguanosine 3':5'-monophosphate GMP failed to change either basal or isoproterenol-stimulated vasopressin secretion from incubated NLs. We conclude that in the NL, as well as in brain tissue cultures, the guanylate cyclase-NP receptor complex (most probably the ANP-A subtype) is localized on pituicytes/filial cells rather than on nerve fibers/cells and that cyclic GMP may not be directly involved in the regulation of vasopressin output from the NL.

Expression of vasopressin and opiates but not of oxytocin genes studied by in situ hybridization in embryonic rat brain primary cultures.

Expression of arginine-vasopressin (AVP), oxytocin (OT), dynorphin and enkephalin genes was studied with the in situ hybridization technique in embryonic rat brain serum-free cultures. Neurones were prepared from hypothalamus and extrahypothalamic structures of 16-day-old rat embryos. After 7 days in culture, AVP gene expression occurred in hypothalamic cultures only, whereas ProOT mRNAs were undetectable. By contrast, prodynorphin and proenkephalin mRNAs could be detected in both hypothalamic and extrahypothalamic cultures, however, with a higher number of cells containing proenkephalin mRNAs. These observations demonstrated that AVP, dynorphin and enkephalin, but not OT genes, can be expressed in cultures prepared from embryonic rat brain as young as 16 days old. This is the first report of an early expression of opioid peptide genes within the central nervous system suggesting that opioids could be involved in the early phases of nervous system development.

Characterization of oxytocin-binding sites in primary rat brain cell cultures.

Detection and characterization of oxytocin-binding sites in dissociated brain cell cultures were performed, using a highly selective iodinated oxytocin antagonist [( 125I]OTA). Dissociated cells derived from hypothalamus and extrahypothalamic forebrain of 16-day-old fetal rats were maintained in chemically defined medium in order to enrich the cultures in neuronal cells. Specific binding of [125I]OTA, demonstrated in both hypothalamic and forebrain cell cultures, was temperature- and time-dependent; maximal binding was obtained by incubating the iodinated ligand for 60 min at 37 degrees C. The binding parameter were shown to be identical in both cell type cultures. The Scatchard plot analysis suggested the presence of a single class of binding sites of high affinity (Kd about 0.06 nM) and low binding capacity (Bmax about 4 fmol/dish). The specificity of these binding sites tested in competition experiments revealed that the unlabelled OT antagonist was the most potent in inhibiting specific [125I]OTA binding (Ki = 0.1 nM). A lower affinity, of the nM range was demonstrated for oxytocin (OT), arginine-vasopressin (AVP) and the V1 antagonist, whereas the V2 AVP agonist poorly competed for [125I]OTA binding sites (Ki about 250 nM). In conclusion, the [125I]OTA binding characteristics, identical in both hypothalamic and forebrain cultures, fulfil the classical conditions required for the existence of receptor sites since the binding was reversible, saturable and specific. As these characteristics were similar to those already described in the adult rat, at the central level in hippocampus, and at the periphery in the mammary gland, it could be postulated that [125I]OTA binds to an OT receptor site.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of neurophysin-containing neurons in primary cultures of rat hypothalami is related to the age of the embryo: morphological study and comparison of in vivo and in vitro neurophysins, oxytocin, and vasopressin content.

The morphological development of immunocytochemically identified neurophysin neurons and the evolution of neuropeptide content (neurophysins, vasopressin, and oxytocin) were studied in primary cultures of hypothalami obtained from 15- to 19-day-old embryos. According to their perikaryal surface, two populations of neurons were distinguished: large and small cells. Full development (defined by the perikaryal surface) of these neurons was reached at day 21 only in cultures from 15- or 16-day-old embryos. These two types of neurons may correspond to the magnocellular and parvocellular neurons described in vivo. Total neurophysins, vasopressin, and oxytocin content were measured by specific radioimmunoassays. Ontogeny of neurophysins and vasopressin showed a good correlation between cells cultured from 15- to 16-day-old embryos and hypothalami from age-matched rats. However, oxytocin was never detected in any of the cultures whatever the age of the embryos. Under our experimental conditions, hypothalamic primary cultures from 15- to 16-day-old embryos therefore appeared to be suitable for studying the differentiation and regulation of neurophysin- and vasopressin-containing neurons.