Localized surface plasmon resonance of Au/TiO2(110): substrate and size influence from in situ optical and structural investigation

Localized Surface Plasmon Resonance (LSPR) of noble metal nanoparticles has attracted a lot of attention in recent years as enhancer of the photocatalytic activity in the visible light domain. Rare are the experimental in situ studies, coupling structural and optical responses, but they are mandatory for a deep understanding of the mechanisms underlying LSPR. Herein we present an in situ investigation during the growth of gold nanoparticles (NPs) on TiO₂(110) in the 2-6 nm size range. We probed the structural and morphological properties of the supported nanoparticles by performing GIXRD and GISAXS simultaneously with their optical response in p and s polarizations recorded by SDRS. The rutile surface state turns out to have a major effect on the Au NPs growth and on their plasmonic response, both in frequency and vibration modes. The roughening of the TiO₂(110) surface weakens the interaction strength between the NPs and the substrate, favoring the growth of textured in-plane randomly orientated NPs. Compared to the epitaxial clusters growing on the flat TiO₂ surface, these textured NPs are characterized by a LSPR blue shift and by the presence of LSPR vibration modes perpendicular to the surface for sizes smaller than about 4 nm.

Psychiatry and Primary Care: A Global Medical Care

Patients suffering from psychiatric disorders have a decrease in life expectancy of 15 years compared to the general population. This excess mortality is not related predominantly to suicide but mostly to a higher frequency of somatic diseases, such as cardiovascular, neoplastic, metabolic diseases. Their high prevalence and their low diagnoses are related to a poorer access to screening, prevention and somatic care than in the general population. Indeed, we estimated that more than 60% of patients treated in public psychiatry do not have a general practitioner (GP) in France. The GP has a role in the coordination, prevention and management of patient health care circuit. To allow a better access to general practitioner, a consultation and a somatic network have been created in Lyon. The purpose is to bring the user back into the primary care system, to ensure a durable monitoring, and a better prevention of avoidable diseases. Patients without GP are oriented to the consultation by their referent psychiatry team. During three consultations with a doctor and a nurse, an assessment of the patient's overall health is realized as well as a synthesis and a redirection to the city network. This reinstatement also allows a better communication between somatic and psychiatric care, to insure a more global view of the patient. A work around the re-empowerment and social rehabilitation is carried out to re-anchor the person in the city and in the care, which every citizen is entitled.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Therapeutic patient education: A solution to the treatment of obesity and metabolic syndrome in psychiatry

Introduction/objectives

Obesity and overweight are major public health issues. Obesity is a risk factor associated with many non-communicable diseases such as diabetes, certain types of cancers, musculoskeletal disorders and cardiovascular, dermatological or gastroenterological diseases. Patients with severe psychiatric disorders have a higher risk of developing overweight or obesity than the general population. The risk of obesity in schizophrenics patients can be multiplied by a factor ranging from 2.8 to 3.5. Patients suffering from mood disorder have sightly lower risk of obesity, however we still consider a factor ranging from 1.2 to 1.5. This significant weight gain can be partly explained by medication.

Methods

The hospital centre Le Vinatier, in France, has developed a therapeutic patient education program in helping patients to self-manage their preventable disease. In order to tackle the multifaceted nature of obesity, the program used the expertise of many different professionals: general practitioners, dieticians, dentists, physical adapted education teachers, pharmacists, nurses and so on. This programme is provided for patients suffering from obesity or an overweight complicated by diabetes, or/and metabolic syndrome, and/or history of cardiovascular diseases or/and a failure of a dietary monitoring. The program includes individual care and collective workshops in nutrition, oral heath, body image, adapted physical education, and roundtable.

Results/conclusions

A retrospective study has already shown that this therapeutic patient education program, like others before, presented better results than dietary consultations. A prospective study is currently being carried out to validate these results in the long term and to demonstrate the benefit associated to this program.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

The NEDD8 inhibitor MLN4924 increases the size of the nucleolus and activates p53 through the ribosomal-Mdm2 pathway

The ubiquitin-like molecule NEDD8 is essential for viability, growth and development, and is a potential target for therapeutic intervention. We found that the small molecule inhibitor of NEDDylation, MLN4924, alters the morphology and increases the surface size of the nucleolus in human and germline cells of Caenorhabditis elegans in the absence of nucleolar fragmentation. SILAC proteomics and monitoring of rRNA production, processing and ribosome profiling shows that MLN4924 changes the composition of the nucleolar proteome but does not inhibit RNA Pol I transcription. Further analysis demonstrates that MLN4924 activates the p53 tumour suppressor through the RPL11/RPL5-Mdm2 pathway, with characteristics of nucleolar stress. The study identifies the nucleolus as a target of inhibitors of NEDDylation and provides a mechanism for p53 activation upon NEDD8 inhibition. It also indicates that targeting the nucleolar proteome without affecting nucleolar transcription initiates the required signalling events for the control of cell cycle regulators.

Catalytic properties of supported gold nanoparticles: new insights into the size-activity relationship gained from in operando measurements

The relationship between the catalytic activity and the size was studied in operando in the case of gold nanoparticles on TiO2(110) model catalyst during carbon monoxide oxidation. The geometrical parameters, the shape and the dispersion of the particles on the oxide support were examined in detail. The catalytic activity was found optimum for a nanoparticle diameter of about 2 nm and a height of six atomic monolayers. Above the maximum, it fits a power law of the diameter D(-24 +/- 0.3). This indicates that the low-coordinated sites play a major role in the catalytic activity, however such a model still fails to explain the activity maximum. The nanoparticle sintering was also investigated since it is suspected of being responsible for the decrease of the catalyst activity in the course of time. It was clearly observed for particles with a size around the maximum of activity and smaller. At the very beginning of the CO conversion into CO2, the sintering is strongly activated. The nanoparticles mobility is dependent upon the TiO2(110) surface direction under consideration: it is higher along the [001]TiO2 than along the [1-10]TiO2. Then, the sintering greatly slows down. This could be explained by a nanoparticles' pinning at the step edges. The thermal energy released by the exothermic CO oxidation reaction was evaluated and it suggests that the sintering results from a more complex process than from a reaction-induced local heating.

[Impact of intrathecal morphine on the tolerance of early feeding after cesarean section]

INTRODUCTION

Early feeding is well tolerated in patients undergoing caesarean section under general or regional anaesthesia. Intrathecal morphine is effective for postoperative analgesia but can induce nausea and vomiting which may hamper feeding. This study assessed prospectively the effects of intrathecal morphine on early feeding in patients undergoing caesarean section.

METHODOLOGY

After ethical committee approval, 66 consenting women scheduled for caesarean section were randomized to receive intrathecal morphine 0.1 mg (group M, n=32) or not ("control group", group C, n=34) at the time of intrathecal anaesthesia performed with a 3 ml mixture containing 8.6 mg bupivacaine, 64 microg clonidine and 4.3 microg sufentanil. Standard antiemetic prophylaxis (5 mg dexamethasone + 2 mg tropisetron) was administered intravenously in all patients after umbilical cord clamping. Standardized multimodal analgesia was initiated postoperatively with 1 g of paracetamol and 30 mg of ketorolac given every 6 hours. Analgesia was evaluated by a numeric rating scale (NRS) at 4 hours intervals and 10 mg of oral morphine was administered if the NRS score exceeded 3. All patients received a protein enriched solution, 8 hours after caesarean section and were allowed to eat solid food on postoperative day 1. Nausea and vomiting episodes, gas and/or stools emission, itching, NRS score and morphine consumption were recorded on the first, second and fourth postoperative hour and then every 4 hours during 48 hours.

RESULTS

Nausea was significantly more frequent and persisted longer in group M. Vomiting occurred equally in both groups and stopped after feeding. Gas and/or stools emission appeared within 48 hours postoperatively in 72 and 77 % of patients in group M and group C respectively. Oral morphine consumption was significantly lower in group M (1.9+/-4 vs 6.5+/-7.3mg, p=0.006). When compared to group C, NRS were also lower in group M from the second to the 20th postoperative hour. Itching was observed more frequently and persisted longer in group M.

DISCUSSION AND CONCLUSION

A small dose of intrathecal morphine provided adequate and prolonged pain relief after caesarean section but increased the incidence of nausea and vomiting despite anti-emetic prophylaxis. Oral food intake was not hampered by intrathecal morphine.

Spatially resolved, energy-filtered imaging of core level and valence band photoemission of highly p and n doped silicon patterns

An accurate description of spatial variations in the energy levels of patterned semiconductor substrates on the micron and sub-micron scale as a function of local doping is an important technological challenge for the microelectronics industry. Spatially resolved surface analysis by photoelectron spectromicroscopy can provide an invaluable contribution thanks to the relatively non-destructive, quantitative analysis. We present results on highly doped n and p type patterns on, respectively, p and n type silicon substrates. Using synchrotron radiation and spherical aberration-corrected energy filtering, we have obtained a spectroscopic image series at the Si 2p core level and across the valence band. Local band alignments are extracted, accounting for doping, band bending and surface photovoltage.

Aspects of lateral resolution in energy-filtered core level photoelectron emission microscopy

Lateral resolution is a major issue in photoelectron emission microscopy (PEEM) and received much attention in the past; however a reliable practical methodology allowing for inter-laboratory comparisons is still lacking. In modern, energy-filtered instruments, core level or valence electrons give much lower signal levels than secondary electrons used in still most of the present experiments. A quantitative measurement of the practical resolution obtained with core level electrons is needed. Here, we report on critical measurements of the practical lateral resolution measured for certified semiconducting test patterns using core level photoelectrons imaged with synchrotron radiation and an x-ray PEEM instrument with an aberration-corrected energy filter. The resolution is 250 ± 20 nm and the sensitivity, 38 nm. The different contributions to the effective lateral resolution (electron optics, sample surface imperfections, counting statistics) are presented and quantitatively discussed.

Orientation-dependent work function of in situ annealed strontium titanate

We have used energy-filtered x-ray photoelectron emission microscopy (XPEEM) and synchrotron radiation to measure the grain orientation dependence of the work function of a sintered niobium-doped strontium titanate ceramic. A significant spread in work function values is found. Grain orientation and surface reducing/oxidizing conditions are the main factors in determining the work function. Energy-filtered XPEEM looks ideally suited for analysis of other technologically interesting polycrystalline samples.

Direct quantification of gold along a single Si nanowire

The presence of gold on the sidewall of a tapered, single silicon nanowire is directly quantified from core-level nanospectra using energy-filtered photoelectron emission microscopy. The uniform island-type partial coverage of gold determined as 0.42+/-0.06 (approximately 1.8 ML) is in quantitative agreement with the diameter reduction of the gold catalyst observed by scanning electron microscopy and is confirmed by a splitting of the photothresholds collected from the sidewall, from which characteristic local work functions are extracted using a model of the full secondary electron distributions.

New reactor dedicated to in operando studies of model catalysts by means of surface x-ray diffraction and grazing incidence small angle x-ray scattering

A new experimental setup has been developed to enable in situ studies of catalyst surfaces during chemical reactions by means of surface x-ray diffraction (SXRD) and grazing incidence small angle x-ray scattering. The x-ray reactor chamber was designed for both ultrahigh-vacuum (UHV) and reactive gas environments. A laser beam heating of the sample was implemented; the sample temperature reaches 1100 K in UHV and 600 K in the presence of reactive gases. The reactor equipment allows dynamical observations of the surface with various, perfectly mixed gases at controlled partial pressures. It can run in two modes: as a bath reactor in the pressure range of 1-1000 mbars and as a continuous flow cell for pressure lower than 10(-3) mbar. The reactor is connected to an UHV preparation chamber also equipped with low energy electron diffraction and Auger spectroscopy. This setup is thus perfectly well suited to extend in situ studies to more complex surfaces, such as epitaxial films or supported nanoparticles. It offers the possibility to follow the chemically induced changes of the morphology, the structure, the composition, and growth processes of the model catalyst surface during exposure to reactive gases. As an example the Pd(8)Ni(92)(110) surface structure was followed by SXRD under a few millibars of hydrogen and during butadiene hydrogenation while the reaction was monitored by quadrupole mass spectrometry. This experiment evidenced the great sensitivity of the diffracted intensity to the subtle interaction between the surface atoms and the gas molecules.

Double dissociation in neural correlates of visual working memory: A PET study

Using positron emission tomography (PET), we investigated the organisation of spatial versus object-based visual working memory in 11 normal human subjects. The paradigm involved a conditional colour-response association task embedded within two visual working memory tasks. The subject had to remember a position (spatial) or shape (object-based) and then use this to recover the colour of the matching element for the conditional association. Activation of the nucleus accumbens and the anterior cingulate cortex was observed during the conditional associative task, indicating a possible role of these limbic structures in associative memory. When the 2 memory tasks were contrasted, we observed activation of 2 distinct cortical networks: (1) The spatial task activated a dorsal stream network distributed in the right hemisphere in the parieto-occipital cortex and the dorsal prefrontal cortex, and (2) The non spatial task activated a ventral stream network distributed in the left hemisphere in the temporo- occipital cortex, the ventral prefrontal cortex and the striatum. These results support the existence of a domain-specific dissociation with dorsal and ventral cortical systems involved respectively in spatial and non spatial working memory functions.

Parenteral nutrition practices in hospital pharmacies in Switzerland, France, and Belgium

OBJECTIVE

Important changes in administering total parenteral nutrition (PN) admixtures have occurred over the past decade. This study describes hospital pharmacists' practices in France (F), Switzerland (CH), and Belgium (B).

METHODS

From the responses received using a standardized questionnaire, (n = 378) we determined the origin, types of container used, and choice of PN formula (standard versus tailor-made) and the type of quality control and the existence of nutrition support teams.

RESULTS

The mean response rates were 55.6% (CH), 30.5% (F), and 24.5% (B). Standard formulas were used mainly for adult patients (CH, 86%; F, 79%; B, 86%), whereas approximately 50% of tailor-made PN bags were used for children. Single-compartment or multicompartment bags or glass bottles contained standard formulas. Most standard formulas were provided by industry, apart from (B), where 50% of PN solutions were compounded by hospital pharmacies. Single-compartment bags contained generally tailor-made formulas produced exclusively by hospital pharmacies in (CH) and (B), whereas 33% were provided by industry in (F). Quality controls were mostly visual and occurred in 75% to 95% of hospitals. Nutrition support teams were present in 32% to 45% of hospitals.

CONCLUSION

The choice, origin, and type of container used for PN formulas were highly variable among countries. However, the use of standard formulas in bags was predominant in (CH) and (B). The function of nutrition support teams was similar in (F), (CH), and (B).

An enhancer element 6 kb upstream of the mouse HNF4alpha1 promoter is activated by glucocorticoids and liver-enriched transcription factors

We have characterized a 700 bp enhancer element around -6 kb relative to the HNF4alpha1 transcription start. This element increases activity and confers glucocorticoid induction to a heterologous as well as the homologous promoters in differentiated hepatoma cells and is transactivated by HNF4alpha1, HNF4alpha7, HNF1alpha and HNF1beta in dedifferentiated hepatoma cells. A 240 bp sub-region conserves basal and hormone-induced enhancer activity. It contains HNF1, HNF4, HNF3 and C/EBP binding sites as shown by DNase I footprinting and electrophoretic mobility shift assays using nuclear extracts and/or recombinant HNF1alpha and HNF4alpha1. Mutation analyses showed that the HNF1 site is essential for HNF1alpha transactivation and is required for full basal enhancer activity, as is the C/EBP site. Glucocorticoid response element consensus sites which overlap the C/EBP, HNF4 and HNF3 sites are crucial for optimal hormonal induction. We present a model that accounts for weak expression of HNF4alpha1 in the embryonic liver and strong expression in the newborn/adult liver via the binding sites identified in the enhancer.

Discrimination and identification of coastal Douglas-fir clones using needle flavonoid fingerprints

This paper describes a method for discriminating and identifying 10 successful Douglas-fir (Pseudotsuga menziesii var. menziesii) clones using foliar flavonoids. All the 101 individuals analyzed by high performance liquid chromatography contained two proanthocyanidins: prodelphinidin and procyanidin and six flavonols: myricetin, quercetin, larycitrin, kaempferol, isorhamnetin and syringetin, but in different proportions. The experimental protocol used was very reproducible since the variation coefficients for each flavonoid did not exceed 9%. Submission of the flavonoid data to multivariate discriminant analysis allowed excellent discrimination of the 10 clones with 89% of the individuals being well-grouped. Then a clonal bank was established in which the fingerprint of each clone is defined by its position in the multidimensional space of the discriminant analysis. The clonal identity of several unknown individuals was determined with success by projecting their flavonoid data in a subsequent discriminant analysis.

Phenotypic effects of the forced expression of HNF4 and HNF1alpha are conditioned by properties of the recipient cell

Tagged versions of HNF4 or HNF1alpha cDNAs in expression vectors have been introduced by transient and stable transfection into three cell lines of hepatic origin that all fail to express these two liver-enriched transcription factors and hepatic functions. C2 and H5 cells are dedifferentiated rat hepatoma variants and WIF12-E cells are human fibroblast-rat hepatoma hybrids with a reduced complement of human chromosomes. Transfectants were analyzed for the expression state of the endogenous genes coding for these transcription factors and for hepatic functions. Each cell line showed a different response to the forced expression of the transcription factors. In C2 cells, no measurable effect was observed, either upon transitory or stable expression. H5 cells reexpressed the endogenous HNF4 gene only upon transient HNF1alpha transfection, and the endogenous HNF1alpha gene only in stable HNF4 transfectants. WIF12-E cells responded to the forced transient or stable expression of either HNF1alpha or HNF4 by cross-activation of the corresponding endogenous gene. In addition, the stable transfectants reexpress HNF3alpha and C/EBPalpha, as well as all of the hepatic functions examined. Hybrid cells similar to WIF12-E had previously been observed to show pleiotropic reexpression of the hepatic phenotype in parallel with loss of human chromosome 2. For the stable WIF12-E transfectants, it was verified that reexpression of the hepatic phenotype was not due to loss of human chromosome 2. The demonstration of reciprocal cross-regulation between HNF4 and HNF1alpha in transient as well as stable transfectants implies that direct effects are involved.

[The cardiological progression under scrutiny of medicometrics. The case for cardiovascular prevention]

The utility of a new global approach to public health planning, "medicometry", is demonstrated using the example of cardiovascular prevention with its costs and benefits. Although cost-benefit analyses have become plethoric in recent years, they do not give the answers to the right questions asked by a society concerned by the explosion of investments in health care. Medicometry illustrates the complexity of the choices in cardiology and proposes alternative solutions different from simplistic proposals for short term budget cuts. For this demonstration several examples are used: the monetary gains of secondary and primary prevention; the impact of the geographical distribution of physicians on medical utilization; self-control of quality; and the impact of scientific and technologic developments on future costs. The impact of health care choices on the whole of society is stressed. The global feed-back of all medical branches, such as cardiology, is explained taking into account quality-of-life targets and economic, demographic and social constraints.

Phosphorylation sites in ligand-induced and ligand-independent activation of the progesterone receptor

Steroid hormone receptors are phosphoproteins that undergo hyperphosphorylation upon binding of hormone. The mechanism and the role of this reaction remain poorly understood. Two-dimensional analysis of ligand-free progesterone receptor (PR) tryptic digests showed the existence of seven main phosphopeptides. Incubation of the cells with the progestin R5020 led to a global increase in the levels of PR phosphorylation. However, the same phosphopeptides were seen, and their levels of labeling relative to each other were unchanged. A similar result was observed after incubation of cells with the antiprogestin RU486. The antiprogestin ZK98299 demonstrated only half of the activity of RU486 in terms of receptor hyperphosphorylation, but the same phosphopeptides, proportionally labeled to the same extent, were observed by chromatography electrophoresis. Ligand-induced DNA binding did not play a role in receptor hyperphosphorylation since the mutant delta 547-592, which is devoid of the first zinc finger region, exhibited the same phosphopeptides, labeled to the same extent, as did wild-type receptor after incubation of cells with hormone. These results suggest that the same kinase(s) act in vivo on ligand-free and on agonist or antagonist-bound progesterone receptor. Binding of different ligands produces different conformational changes in the ligand binding domain of the receptor which enhance, to varying extents, affinity of the receptor for the kinase(s). The DNA binding region also plays a role in the interaction with the kinase(s), although binding to DNA per se is not necessary for the hyperphosphorylation of the receptor to take place.(ABSTRACT TRUNCATED AT 250 WORDS)

The progesterone receptor. Biological effects of progestins and antiprogestins

The progesterone receptor displays the typical three-domains structure of the steroid-thyroid receptor family. The central domain contains two 'zinc finger' structures responsible for the specific recognition of the cognate DNA sequences. The carboxy-terminal domain contains the hormone and anti-hormone binding site. Progesterone and synthetic progestins (R5020, Org 2058) activate the receptor, provoke its phosphorylation and DNA-binding ability and induce its regulatory activities. The antagonist RU38486 elicits the same sequence of events but leads to an abortive conclusion without specific gene transactivation. The progesterone receptor is down-regulated by its own ligand at the transcriptional level through inhibition of oestrogen receptor-mediated induction through protein-protein interactions. This mechanism is also inhibited by RU38486.

Specific binding of progesterone receptor to progesterone-responsive elements does not require prior dimerization

Steroid-hormone receptors undergo, prior to binding to DNA, a hormone-dependent dimerization. It is generally accepted that this dimerization is indispensable for the high-affinity binding of hormone receptor to hormone-responsive elements. Using a progesterone-receptor mutant with the complete steroid-binding domain deleted (positions 663-930), with or without the epitope required for binding the monoclonal antibody Let 126, we have shown that this receptor species was unable to undergo dimerization in solution. However, this mutant retained a high affinity (60-70% of the affinity of the wild-type receptor) for the progesterone-responsive elements of the mouse-mammary-tumor-virus long-terminal-repeat promoter and for a consensus palindromic progesterone-responsive element, as measured by both DNase-I protection experiments and gel-shift experiments. This mutant also increased gene transcription. Thus, at least in the case of the progesterone receptor, prior dimerization is dispensable for receptor binding to regulatory DNA elements and for subsequent transcription activation.

Failure of thiamphenicol in a penicillin-allergic patient with Listeria meningoencephalitis--delayed cure following penicillin desensitization

A 27-year-old woman, without compromised immunodefenses, experienced a Listeria meningoencephalitis, with brainstem symptoms. The identified agent exhibited poor susceptibility to usual effective antibiotics, except for penicillins. Knowledge of past history of an allergic reaction to beta-lactam antibiotics lead to appropriate therapy after acute intravenous desensitization of the patient to amoxicillin. Treatment resulted in therapeutic administration rate over 24 h, and in rapid regression of clinical and biological disorders.

In two genes, synergism of steroid hormone action is not mediated by cooperative binding of receptors to adjacent sites

Synergistic action of multiple steroid hormone response elements (HREs) has been proposed to be due to cooperative binding of receptors. We have studied the cooperativity of steroid hormone receptor binding to synergistic HREs in two natural genes. In the mouse mammary tumor virus long terminal repeat that contains four progesterone receptor binding sites, no cooperativity in receptor binding was observed between the single distal and the three proximal sites whereas a low level of cooperativity in receptor binding (about 2-fold) was found between the three proximal sites. This contrasted with the very strong synergism of these four HREs in stimulation of transcription. In the chicken vitellogenin II gene upstream sequences, an estrogen and a progestin response elements act synergistically. In this case again, no cooperativity of binding of the estrogen and progesterone receptors to their respective binding sites was observed. We therefore conclude that cooperative receptor binding may not always be required for synergistic action of multiple HREs.

Characterization of the hormone responsive element involved in the regulation of the progesterone receptor gene

The transcription of the progesterone receptor gene is induced by estrogens and decreased by progestins. Studies were performed to define the regions of the gene and the molecular mechanisms involved. No hormonal regulation could be observed using 5' flanking regions of the gene up to -2762 in front of a heterologous gene. Estrogen and progestin regulation could be observed only when using fragments of the gene extending down to +788. Progressive deletions from the 5' and 3' ends, site-directed mutagenesis and DNase protection experiments with purified estrogen receptor suggested that the biologically active estrogen responsive element (ERE) is present at +698/+723, overlapping the initiation of translation. An oligonucleotide was synthesized bearing this ERE and shown to impart estrogen inducibility to a heterologous gene. Its regulation by anti-estrogens corresponded to that of the in situ progesterone receptor gene since tamoxifen was a partial agonist whereas ICI 164384 was a full antagonist. This ERE also mediated down-regulation by progestins in the presence of the progesterone receptor, even though it has no progesterone receptor binding ability. DNase footprinting showed that this effect was not due to a decrease of estrogen receptor affinity for the ERE in the presence of progesterone receptor. Finally, use of deletion mutants of the progesterone receptor showed that the steroid binding and the DNA binding domains were necessary for down-regulation whereas deletions of various parts of the N-terminal domain were without effect.

Post-transcriptional analysis of rat mitochondrial D-3-hydroxybutyrate dehydrogenase control through development and physiological stages

The nuclear encoded mitochondrial D-3-hydroxybutyrate dehydrogenase (BDH) is synthesized in the cytosal as a larger precursor. This membrane enzyme which requires lecithin for activity plays an essential role in energy metabolism as a ketone bodies-converting enzyme. A cDNA clone of the rat liver enzyme encompassing an antigenic determinant peptide has been isolated after immunoscreening of a lambda gt11 expression library. The nucleotide sequence of this 279-base cDNA insert contains a single open reading frame of 93 amino-acids, which represents about a third of the mature enzyme. Amino-acid sequence analysis predicts a hydrophobic stretch of 29 amino-acids long which probably functions as membrane anchor domain, or as an important region for the enzyme activation by phospholipid. By using this cDNA probe the BDH gene has been investigated at the mRNA level. There is only one mRNA (2-kb size) for BDH whatever the studied tissue. The rat gene is differently expressed since its mRNA is already present in the foetus liver while the BDH polypeptide amount is low and its enzymatic activity is not detectable even in the late stage of foetal development. The mRNA content is higher in the liver than in extrahepatic tissues. Adrenalectomy and ovariectomy increase liver mRNA content and polypeptide level, as well as activity of BDH. These effects are totally or partially abolished by corticosterone and estradiol treatments respectively. In addition, a 15-day hyperlipidic diet stimulates BDH gene expression. Present results show that the gene expression of this mitochondrial enzyme is modulated through development and hormonal and metabolic conditions mentioned above.

Variations of specific mRNA and polypeptide contents of rat liver D-beta-hydroxybutyrate dehydrogenase during an experimental diabetes mellitus

The expression of the rat liver D-beta-hydroxybutyrate dehydrogenase (BDH) gene was investigated at different levels: the level of its specific mRNA, the protein content and the enzymatic activity. By using a cDNA probe, we found that the BDH mRNA was about 2 kb and we report here that the decrease of BDH activity in diabetic rats is due to a reduction in the content of the enzyme, which is proportional to a diminution in the amount of the BDH mRNA. We also show that insulin is able to reverse this diabetes effect by restoring the level of BDH mRNA, the BDH content and thus its activity. This result indicates that in vivo the control of the expression of the BDH gene by insulin is mainly transcriptional and/or post-transcriptional (mRNA stability).

Structural and functional studies of mammalian progesterone receptors

During the past years there has been an improvement in our understanding of the molecular mechanism of action of the progesterone receptor (PR). This was due to the obtention of monoclonal antibodies against PR which allowed the first structural analyses and led to the cloning of the genes.

Immunoreactive somatomedin C in children from Morocco: a biological marker of nutritional growth retardation?

Somatomedin C (Sm-C) is supposed to be a sensitive marker of malnutrition. Its relationship to growth and protein intake was investigated in 47 Moroccan children. The children (mean age: 7.5 +/- 2 yr) had no endocrine abnormality. Anthropometric parameters were measured, together with blood levels of Sm-C and growth hormone (GH). Lower values of Sm-C were found in the following situations: (a) growth retardation (more than -2 Sd, N = 23; Sm-C = 3.61 +/- 0.42 nmol/l vs. 13.38 +/- 1.52, P less than 0.02); (b) body weight less than 80% of expected weight for height (N = 8; Sm-C = 4.84 +/- 0.97 vs. 10.33 +/- 1.19, P less than 0.02); (c) boys with meat consumption less than 3 times per wk (N = 15; Sm-C = 4.03 +/- 0.71 vs. 12.35 +/- 2.01, P less than 0.002). Thus, lower values of Sm-C are found in association with weight insufficiency and lower protein intake. As has previously been assumed, serum Sm-C, which is regulated by nutrition, may be a sensitive tool in the assessment of nutritional status in developing countries such as Morocco. Furthermore, it could explain some cases of growth retardation in states of malnutrition.

[Results of weight-loss treatment at a hospital. Significance of the administration of triiodothyronine in small doses during a protein diet]

We report the short-term effects of very-low-calorie liquid formula diet (n = 51) and of 600 Kcalories diet (n = 13) in patients who were hospitalized during 3 weeks. Weight loss averaged 278 +/- 14 g/day (m +/- SEM). It was slightly higher with the very-low-calorie liquid formula diet (293 +/- 21 g vs 242 +/- 25 g, N.S.). Individual weight-loss was unpredictable and highly variable; it ranged from 62 to 636 g/day. During the very-low-calorie formula diet, the expected low T3 syndrome was observed and 12 patients were given T3 (25 micrograms during the second week and 50 micrograms during the third week). These rather small doses corrected T3 values, but lowered total and free T4 levels. T3 administration did not modify the magnitude of weight loss in our patients.

Receptors bound to antiprogestin from abortive complexes with hormone responsive elements

The mechanism of action of antisteroids is not understood and explanations of their antagonistic activity have been sought at all levels of hormone action. It has been proposed that antisteroids, after binding to receptor, trap it into a non-activated (non DNA-binding) form possibly through interaction with a heat-shock protein of relative molecular mass (Mr) 90,000 (90 K), or that the antisteroids provoke binding of receptor to nonspecific DNA sites but not to hormone responsive elements (HREs), or that the antisteroid-receptor complexes can bind to HREs but form abortive complexes that fail to regulate transcription. We have constructed a deleted cDNA encoding a mutant form of rabbit progesterone receptor which exhibits constitutive activity, that is, binds to HREs in the absence of hormone and thus bypasses the first two steps discussed above. Co-transfection experiments allowed the expression of both constitutive and wild-type receptors in the same recipient cells. Antiprogestin RU486-wild-type receptor complexes completely suppressed the activity of the constitutive receptor on a reporter gene, showing that the inhibition is at the level of their common responsive elements.

Estrogen and progesterone receptor-binding sites on the chicken vitellogenin II gene: synergism of steroid hormone action

The chicken vitellogenin II gene is transcriptionally activated by estrogens. In transient transfection experiments in human T47D cells that contain receptors for various steroids, we showed estradiol, progestin, and androgen responses of a chimeric chicken vitellogenin II construct. This construct consists of DNA sequences from -626 to -590 upstream of the start of transcription of the chicken vitellogenin gene linked to the herpes simplex virus thymidine kinase promoter driving the transcription of the bacterial chloramphenicol acetyltransferase gene. Treatment of the transfected T47D cells with a combination of estradiol and the progestin R5020 led to a superinduction of chloramphenicol acetyltransferase activity, showing a synergistic action of these two steroids. This synergism was not observed upon treatment of the transfected cells with estradiol and the androgen dihydrotestosterone. Using point mutations in the vitellogenin gene fragment, we showed in functional and in in vitro DNase I footprinting assays with a purified progesterone receptor that, for the synergistic action of estradiol and R5020 to occur, the progesterone receptor must be bound to the vitellogenin gene fragment. The progesterone receptor-binding site was localized at -610 to -590, close to the consensus sequence (-626 to -613) for estrogen receptor binding and function. We therefore demonstrate here that two different steroid hormones can be functionally synergistic through the interaction of their corresponding receptors with two different binding sites adjacent to one another.

Fatty acid composition and kinetic behaviour of liver retinyl esters in vitamin A sufficient and deficient rats

Weanling rats were fed vitamin A deficient diets (-A) or diets supplemented with vitamin A (+A) (4.4 mg retinol equivalents/kg diet) for a period of 7 or 6 wk, respectively. In liver tissues of these two groups of animals both the subcellular localization as well as the fatty acid composition of the retinyl esters was studied. During vitamin A supplementation or deprivation, the kinetics of the different ester forms were investigated. Results indicate that the subcellular localization of all retinyl esters is similar and dependent on age. Two pools exist, ie one consisting of the nuclear/cell debris and mitochondrial-lysosomal fractions and the other containing the microsomal and cytosol fractions. HPLC analysis showed retinyl palmitate as the predominating (80%) form of the various retinyl esters. By supplementation clearly two kinetic behaviours can be demonstrated: one being a relatively stable storage of the palmitate and stearate, increasing with time and the second one being a more labile pattern for the ester forms with other saturated and unsaturated fatty acids. By vitamin A depletion all retinyl esters are affected indicating that the ester forms other than palmitate and stearate are also storage forms of vitamin A.

Association of DNA-bound progesterone receptors

Steroid hormone-receptor complexes regulate the transcription of specific genes. Recent studies of high-affinity interactions between the receptors and discrete regions of DNA, together with gene-transfer experiments, have led to the precise mapping of hormone regulatory elements. Nothing is known, however, about the mechanisms whereby DNA-bound receptors modulate gene transcription. At the start of transcription in prokaryotes two oligomeric molecules of several regulatory proteins must bind to two specific DNA sites and interact with one another to regulate the binding of RNA polymerase to DNA. Using electron microscopy to observe progesterone receptor binding to regulatory regions of uteroglobin and mouse mammary tumour virus genes, we demonstrate a similar binding between receptor oligomers at two DNA sites. DNA loops are formed when the hormone regulatory elements are at a distance from one another. Thus, in common with certain prokaryotic systems, protein-protein interactions may be important in steroid hormone regulation of gene transcription.

The usefulness of fructosamine determination in diabetic patients and its relation to metabolic control

In 116 diabetics and 101 control subjects, we measured both HbA1 and fructosamine values, neither could definitely separate the 2 populations. We observed an excellent correlation between both variables and between each of them and various other parameters of metabolic control. It appeared that the correlation with recent (4 weeks) diabetes control was better with fructosamine than with HbA1 levels. The opposite was true when a 8 week period was considered. The presence of diabetic complications did not modify the fructosamine levels. These results confirm the value of fructosamine measurement in the evaluation of recent diabetes control, but clearly, HbA1 determination remains the best parameter of long-term glycemic control.

Sequence-specific DNA binding of the progesterone receptor to the uteroglobin gene: effects of hormone, antihormone and receptor phosphorylation

The effects of ligand binding and receptor phosphorylation on the interaction of progesterone receptor with specific DNA sequences in the uteroglobin gene were studied by nitro-cellulose filter binding and DNase I footprinting. High affinity sites were mapped upstream from the transcription start and in the first intron. They contained a common TGTTCACT sequence. These sites were occupied with similar affinity by the receptor, either in its free state, or complexed with the hormone or an antagonist (RU486); and also by receptor which had been phosphorylated in vivo in a hormone-dependent manner. In all cases identical footprints were observed. These experiments led to the following conclusions. The hormone-dependency of receptor binding to DNA or chromatin is observed in intact cells and in crude cellular extracts but not with purified receptor. Thus in situ, the unliganded receptor probably interacts with some nuclear component(s) which stabilizes it in a 'non-activated' form (non-chromatin and non-DNA binding form). When isolated, the receptor may undergo activation, even in the absence of the hormone. Binding by receptor of an antihormone (and possibly receptor phosphorylation) exerts an effect on gene transcription through a mechanism which is different from (and probably follows) receptor interaction with the gene.

Zinc deficiency and lymphocyte subpopulations. A study by flow cytometry

Zinc deficiency is well known to alter immunity. We report the case of a 18-yr-old female with relapsing Crohn's disease who experienced acrodermatitis enteropathica due to zinc deficiency during total parenteral nutrition (TPN). Blood lymphocytes have been studied by flow cytometry: before zinc treatment an important decrease of T-helper lymphocytes with high level of OKM-5+ lymphocytes had been observed. Zinc-supplemented diet induced within a few days, a rise of T-helper lymphocytes and a proportional reduction of OKM5+ cells. Increased values of high metabolism surface marker (OKT-9) were also observed, as well as cytoplasmic modifications. The authors suggest that lymphocyte surface markers could be useful to monitor TPN in patients at high risk for zinc deficiency.