Zinc unbound concentration as an anchor to drive individualize repletion.

BACKGROUND AND AIMS: Zinc (Zn) quantification is of particular interest in many clinical condition (e.g. inflammatory disease, critical care). Currently, Zn status is assessed by measuring plasma/serum concentration. This concentration corresponds to the sum of unbound Zn (Zn-Cu) and Zn highly bound to albumin (Zn-Cb). METHODS: Using a pharmacokinetic approach to the interpretation of total Zn concentration (Zn-Ct), taking into account Zn-Cu and the influence of hypoalbuminemia on Zn-Cb, it is possible to improve the individualization of Zn repletion. RESULTS: Therefore, during pregnancy and in certain inflammatory disease situations, repletion may not be necessary. However, as in critical care, it would be more appropriate to perform Zn-Cu assays to improve Zn repletion. CONCLUSION: Coupled total and unbound Zn should be monitored in order to individualize Zn repletion.

Identification of the ectoenzyme CD38 as a marker of committed preadipocytes.

BACKGROUND/OBJECTIVES: Characterisation of the adipocyte cellular lineage is required for a better understanding of white adipose tissue homoeostasis and expansion. Although several studies have focused on the phenotype of the most immature adipocyte progenitors, very few tools exist to identify committed cells. In haematopoiesis, the CD38 ectoenzyme is largely used to delineate various stages of stem cell lineage commitment. We hypothesise that this marker could be used to identify committed preadipocytes. METHODS: Complementary strategies including flow cytometry, cell-sorting approaches, immunohistochemistry and primary cultures of murine adipose progenitors isolated from different fat pads of control or high-fat diet exposed C57BL/6 J mice were used to determine the molecular expression profile, proliferative and differentiation potentials of adipose progenitors expressing the CD38 molecule. RESULTS: We demonstrate here that a subpopulation of CD45- CD31- CD34+ adipose progenitors express the cell surface protein CD38. Using a cell-sorting approach, we found that native CD45- CD31- CD34+ CD38+ (CD38+) adipose cells expressed lower CD34 mRNA and protein levels and higher levels of adipogenic genes such as Pparg, aP2, Lpl and Cd36 than did the CD45- CD31- CD34+ CD38- (CD38-) population. When cultivated, CD38+ cells displayed reduced proliferative potential, assessed by BrdU incorporation and colony-forming unit assays, and greater adipogenic potential. In vitro, both CD38 mRNA and protein levels were increased during adipogenesis and CD38- cells converted into CD38+ cells when committed to the adipogenic differentiation programme. We also found that obesity development was associated with an increase in the number of CD38+ adipose progenitors, this effect being more pronounced in intra-abdominal than in subcutaneous fat, suggesting a higher rate of adipocyte commitment in visceral depots. CONCLUSIONS: Together, these data demonstrate that CD38 represents a new marker that identifies committed preadipocytes as CD45- CD31- CD34low CD38+ cells.

Pro-inflammatory phospholipid arachidonic acid/eicosapentaenoic acid ratio of dysmetabolic severely obese women.

BACKGROUND: Fatty acids (FAs) and adipokines such as adiponectin or interleukin-6 (IL-6) are known to modulate inflammation and the development of metabolic syndrome. Whether FA composition assessed in plasma triacylglycerols (TAGs), phospholipids (PLs) and non-esterified fatty acids (NEFAs) and adipose tissue (AT) PLs differed between dysmetabolic and non-dysmetabolic severely obese women remains to be established. Whether the plasma and/or AT arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio in the PL sub-fraction may be associated with adipokine AT gene expression needs to be examined. METHODS: FA composition was measured in plasma lipid classes and in the TAG and PL sub-fractions of subcutaneous abdominal and omental ATs of severely obese women paired for age and adiposity but showing a dysmetabolic profile (n = 13) or not (n = 14). FA profile was assessed by gas chromatography. Plasma and AT mRNA concentrations of adiponectin and IL-6 were measured by ELISA and real-time polymerase chain reaction, respectively. RESULTS: Plasma adiponectin and FA concentrations in the NEFA sub-fraction were, respectively, lower and higher in dysmetabolic than in non-dysmetabolic women (p < 0.05). Despite similar FA levels in the PL sub-fraction, the AA/EPA ratio was higher in plasma and ATs (p < 0.005), because of an EPA decrease in plasma and subcutaneous abdominal fat vs. an AA increase in the omental depot. The AA/EPA ratio was negatively associated with adiponectin concentrations in plasma and subcutaneous abdominal AT (0.01 < p < 0.05). CONCLUSIONS: Metabolic dysfunction is associated with a pro-inflammatory phospholipid AA/EPA ratio in plasma and ATs, and an altered adiponectin secretion that could contribute to developing metabolic syndrome.

French hospital nurses' opinion about euthanasia and physician-assisted suicide: a national phone survey.

BACKGROUND: Hospital nurses are frequently the first care givers to receive a patient's request for euthanasia or physician-assisted suicide (PAS). In France, there is no consensus over which medical practices should be considered euthanasia, and this lack of consensus blurred the debate about euthanasia and PAS legalisation. This study aimed to investigate French hospital nurses' opinions towards both legalisations, including personal conceptions of euthanasia and working conditions and organisation. METHODS: A phone survey conducted among a random national sample of 1502 French hospital nurses. We studied factors associated with opinions towards euthanasia and PAS, including contextual factors related to hospital units with random-effects logistic models. RESULTS: Overall, 48% of nurses supported legalisation of euthanasia and 29%, of PAS. Religiosity, training in pallative care/pain management and feeling competent in end-of-life care were negatively correlated with support for legalisation of both euthanasia and PAS, while nurses working at night were more prone to support legalisation of both. The support for legalisation of euthanasia and PAS was also weaker in pain treatment/palliative care and intensive care units, and it was stronger in units not benefiting from interventions of charity/religious workers and in units with more nurses. CONCLUSIONS: Many French hospital nurses uphold the legalisation of euthanasia and PAS, but these nurses may be the least likely to perform what proponents of legalisation call "good" euthanasia. Improving professional knowledge of palliative care could improve the management of end-of-life situations and help to clarify the debate over euthanasia.

Coadministration of coenzyme Q prevents rosiglitazone-induced adipogenesis in ob/ob mice.

OBJECTIVE: The aim of this study is to determine the effect of coenzyme Q (Q) on ob/ob mice treated or not with thiazolidinedione (TZD). DESIGN AND MEASUREMENTS: Ob/ob mice were treated with Q, Rosiglitazone or a combination of both molecules for 13 days; physical and metabolic parameters as well as oral glucose tolerance test were assessed. mRNA expression of genes of energy dissipation and storage were measured by real-time PCR. RESULTS: Q treatment improved some metabolic parameters in ob/ob mice. Surprisingly, cotreatment with Rosiglitazone and Q improved metabolic parameters and prevented TZD increase in body weight and adiposity, mainly by increasing lipid oxidation in adipose tissue, reducing lipid synthesis and balancing adipokine gene expression. CONCLUSIONS: Our finding suggests that Rosiglitazone and coenzyme Q bitherapy could prevent the body weight gain associated with adipogenesis and could improve the clinical use of these compounds.

Functional dynamic compartmentalization of respiratory chain intermediate substrates: implications for the control of energy production and mitochondrial diseases.

Activity defects in respiratory chain complexes are responsible for a large variety of pathological situations, including neuromuscular diseases and multisystemic disorders. Their impact on energy production is highly variable and disproportional. The same biochemical or genetic defect can lead to large differences in clinical symptoms and severity between tissues and patients, making the pathophysiological analysis of mitochondrial diseases difficult. The existence of compensatory mechanisms operating at the level of the respiratory chain might be an explanation for the biochemical complexity observed for respiratory defects. Here, we analyzed the role of cytochrome c and coenzyme Q in the attenuation of complex III and complex IV pharmacological inhibition on the respiratory flux. Spectrophotometry, HPLC-EC, polarography and enzymology permitted the calculation of molar ratios between respiratory chain components, giving values of 0.8:61:3:12:6.8 in muscle and 1:131:3:9:6.5 in liver, for CII:CoQ:CIII:Cyt c:CIV. The results demonstrate the dynamic functional compartmentalization of respiratory chain substrates, with the existence of a substrate pool that can be recruited to maintain energy production at normal levels when respiratory chain complexes are inhibited. The size of this reserve was different between muscle and liver, and in proportion to the magnitude of attenuation of each respiratory defect. Such functional compartmentalization could result from the recently observed physical compartmentalization of respiratory chain substrates. The dynamic nature of the mitochondrial network may modulate this compartmentalization and could play a new role in the control of mitochondrial respiration as well as apoptosis.

French district nurses' opinions towards euthanasia, involvement in end-of-life care and nurse patient relationship: a national phone survey.

OBJECTIVES: To assess French district nurses' opinions towards euthanasia and to study factors associated with these opinions, with emphasis on attitudes towards terminal patients. DESIGN AND SETTING: An anonymous telephone survey carried out in 2005 among a national random sample of French district nurses. PARTICIPANTS: District nurses currently delivering home care who have at least 1 year of professional experience. Of 803 district nurses contacted, 602 agreed to participate (response rate 75%). MAIN OUTCOME MEASURES: Opinion towards the legalisation of euthanasia (on a five-point Likert scale from "strongly agree" to "strongly disagree"), attitudes towards terminal patients (discussing end-of-life issues with them, considering they should be told their prognosis, valuing the role of advance directives and surrogates). RESULTS: Overall, 65% of the 602 nurses favoured legalising euthanasia. Regarding associated factors, this proportion was higher among those who discuss end-of-life issues with terminal patients (70%), who consider competent patients should always be told their prognosis (81%) and who value the role of advance directives and surrogates in end-of-life decision-making for incompetent patients (68% and 77% respectively). Women and older nurses were less likely to favour legalising euthanasia, as were those who believed in a god who masters their destiny. CONCLUSIONS: French nurses are more in favour of legalising euthanasia than French physicians; these two populations contrast greatly in the factors associated with this support. Further research is needed to investigate how and to what extent such attitudes may affect nursing practice and emotional well-being in the specific context of end-of-life home care.

Physiological diversity of mitochondrial oxidative phosphorylation.

To investigate the physiological diversity in the regulation and control of mitochondrial oxidative phosphorylation, we determined the composition and functional features of the respiratory chain in muscle, heart, liver, kidney, and brain. First, we observed important variations in mitochondrial content and infrastructure via electron micrographs of the different tissue sections. Analyses of respiratory chain enzyme content by Western blot also showed large differences between tissues, in good correlation with the expression level of mitochondrial transcription factor A and the activity of citrate synthase. On the isolated mitochondria, we observed a conserved molar ratio between the respiratory chain complexes and a variable stoichiometry for coenzyme Q and cytochrome c, with typical values of [1-1.5]:[30-135]:[3]:[9-35]:[6.5-7.5] for complex II:coenzyme Q:complex III:cytochrome c:complex IV in the different tissues. The functional analysis revealed important differences in maximal velocities of respiratory chain complexes, with higher values in heart. However, calculation of the catalytic constants showed that brain contained the more active enzyme complexes. Hence, our study demonstrates that, in tissues, oxidative phosphorylation capacity is highly variable and diverse, as determined by different combinations of 1) the mitochondrial content, 2) the amount of respiratory chain complexes, and 3) their intrinsic activity. In all tissues, there was a large excess of enzyme capacity and intermediate substrate concentration, compared with what is required for state 3 respiration. To conclude, we submitted our data to a principal component analysis that revealed three groups of tissues: muscle and heart, brain, and liver and kidney.

Weight-dependent changes of immune system in adipose tissue: importance of leptin.

Ancestral lymphoid cells reside in adipose tissues, and their numbers are highly altered in obesity. Leptin, production of which is correlated to fat mass, is strongly involved in the relationships between adipose tissues and immune system. We investigated in epididymal (EPI) and inguinal (ING) fat pads to determine whether 1) lymphocyte phenotypes were correlated to the tissue weight and 2) leptin was involved in such relationships. Immunohistological analyses revealed a tight relationship between the T and NK lymphocytes of the stromal vascular fraction and adipocytes. We identified a significant negative and positive correlation between EPI weight and the percentage of NK and total T cells respectively by cytofluorometric analyses. The NK and ancestral gammadelta T cell contents were directly dependent of leptin since they increased significantly in high-fat (HF) diet mice but not in leptin-deficient (ob/ob) mice as compared to control. By contrast, the alphabeta T cell content seemed independent of leptin because their percentages increased significantly with the EPI weight whatever the type of mice (control, HF, ob/ob). The present study suggests that adipose tissues present, according to their localization, different immunological mechanisms that might be involved in the regulation of adipose cells functions and proliferations.

Individual and combined effects of low oral doses of deoxynivalenol and nivalenol in mice.

Deoxynivalenol (DON) and nivalenol (NIV) are toxic Fusarium secondary trichothecene metabolites that often co-occur regularly in cereal grains. These compounds were compared for their toxicity towards C57BL/6 mice on several parameters including alteration in plasma biochemistry, immune system reactivity and hepatic drug metabolism capacity. Mice received individual or combined oral doses of each toxin: 0.071 or 0.355 mg/kg of body weight, administrated three days a week for 4 weeks. Food consumption was altered by the single administration of 0.355 mg/kg of NIV, although no noticeable change of body and organ weights or liver protein contents was detected. NIV administration did cause also significant changes in total CO2 and uric acid concentrations in plasma. Individual toxin exposures led to increases in plasma IgA without no detectable change in the ex vivo production of cytokine by splenocytes. The liver ethoxyresorufin O-deealkylase, pentoxyresorufin O-depenthylase and glutathione S-transferase activities were increased in concert with cytochrome P4501a and P4502b subfamily expression. Administration of combinations of DON and NIV resulted in responses similar to that observed using individual doses of each toxin. However, depending on the ratio of toxin doses and biochemical parameters, some responses could be also additive (plasma IgA and hepatic DCNB conjugation) or synergistic (plasma uric acid).

Adipose tissues as an ancestral immune organ: site-specific change in obesity.

Close relationships have been demonstrated between adipose tissue and the inflammatory/immune system. Furthermore, obesity is increasingly considered as a state of chronic inflammation. Cytofluorometric analysis reveals the presence of significant levels of lymphocytes in the stroma-vascular fraction of white adipose tissues. In epididymal (EPI) fat, lymphocytes display an "ancestral" immune system phenotype (up to 70% of natural killer (NK), gammadelta+ T and NKT cells among all lymphocytes) whereas the inguinal (ING) immune system presents more adaptive characteristics (high levels of alphabeta+ T and B cells). The percentage of NK cells in EPI fat was decreased in obese mice fed with a high-fat diet, whereas gammadelta positive cells were significantly increased in ING fat. These data support the notion that adipose tissue may elaborate immunological mechanisms to regulate its functions which might be altered in obesity.

Disclosure of prognosis to terminally ill patients: attitudes and practices among French physicians.

BACKGROUND: Disclosure of the prognosis to terminally ill patients is a strong prerequisite for integrating the physical, psychological, spiritual, and social aspects of end-of-life care. OBJECTIVE: This study aimed to assess French physicians' general attitudes and effective practices (with patients followed up to death recently) toward such disclosure. DESIGN/SUBJECTS: We used data from a cross-sectional survey conducted among a national sample of 917 French general practitioners, oncologists, and neurologists. RESULTS: A majority of respondents opted for prognosis disclosure only at patients' request, very few opted for systematic disclosure without patient's request, and a significant minority opted for systematic concealment. Concerning deceased patients described by respondents, 44.5% of competent patients were informed of prognosis by their physician, 27.3% were informed by someone else, 9.0% refused to be informed, and 19.2% were simply not informed. Concealment was more frequent for older patients, and physicians involved in a nongovernmental organization (NGO) for patients' support were more likely to disclose the prognosis, even without patient's request. CONCLUSIONS: Disclosure of the prognosis to terminally ill patients is still far from systematic in France. Further research is needed to better understand the motivations of French physicians' disclosure practices, which are probably culturally shaped.

[Doctors' opinions on palliative care: results from a French survey on physicians attitudes and practices]. / Deux points de vue des médecins sur les soins palliatifs.

OBJECTIVE: To examine practitioners' opinions on palliative care. METHOD: Statistical analyses were carried out on data collected from 1000 physicians recruited to participate in a study on knowledge, attitudes and practices with respect to palliative care ("Palliative Care 2002"). A cluster analysis (CAH) was conducted based on responses to nine questions in order to identify homogeneous and contrasting profiles of opinions on palliative care. RESULTS: Two distinctly different categories of profiles emerged. The first one had a restrictive approach to palliative care (n = 387; 38.7%), while the second one supported its expansion (n = 613; 61.3%). CONCLUSION: A newly revised communication campaign which favoured and recognised palliative care could assist in the dissemination of related practices among physicians.

Biological validation of coenzyme Q redox state by HPLC-EC measurement: relationship between coenzyme Q redox state and coenzyme Q content in rat tissues.

The properties of coenzymes Q (CoQ9 and CoQ10) are closely linked to their redox state (CoQox/total CoQ) x 100. In this work, CoQ redox state was biologically validated by high performance liquid chromatography-electrochemical measurement after modulation of mitochondrial electron flow of cultured cells by molecules increasing (rotenone, carbonyl cyanide chlorophenylhydrazone) or decreasing (antimycin) CoQ oxidation. The tissue specificity of CoQ redox state and content were investigated in control and hypoxic rats. In control rats, there was a strong negative linear regression between tissular CoQ redox state and CoQ content. Hypoxia increased CoQ9 redox state and decreased CoQ9 content in a negative linear relationship in the different tissues, except the heart and lung. This result demonstrates that, under conditions of mitochondrial impairment, CoQ redox control is tissue-specific.

Opinions toward pain management and palliative care: comparison between HIV specialists and oncologists.

Despite the introduction of HAART, pain is still a common symptom in people living with HIV/AIDS. For these persons, pain management supplied by palliative care teams may support standard HIV care. This study compares opinions toward palliative care of 83 HIV specialists and 217 oncologists (French national survey: Palliative Care 2002). Data were collected by phone questionnaire. A cluster analysis was carried out in order to identify contrasted profiles of opinions toward palliative care. A logistic regression was performed to test the relationships between identified clusters and physicians' characteristics. With a two-cluster partition, we observed a profile corresponding to a restrictive conception of palliative care. Within this profile, physicians were more prone to consider that palliative care should be used only for terminally-ill patients, and only after all curative treatments have failed, with a restrained prescriptive power for physicians providing palliative care. This conception was associated with reluctance toward morphine analgesia. Once controlled for other physicians' characteristics, HIV specialists were more likely than oncologists to endorse this restrictive conception (OR=1.9, CI 95% [1.1; 3.3]). Thus French HIV specialists should be more informed about the utility of providing palliative care, even for patients who are not in terminal stage.

[Terminal care of patients by the general practitioner and the specialist. Results of a French survey "Attitudes and practices in palliative treatment--2002"]. / Prise en charge des malades en fin de vie en médecine générale et spécialisée. Résultats de l'enquête française "Attitudes et pratiques face aux soins palliatifs-2002".

OBJECTIVE: Assess the attitude of the practitioners with regard to the management of patients at the end of their lives, depending on the physician/patient communication and treatment of pain. Method Statistical analysis of the data collected among 1,000 practitioners recruited for a survey on knowledge, attitudes and practices regarding palliative care in 2002. RESULTS: The practitioners who felt "ill at ease" in the management of patients at the end of their life often had a poor opinion regarding morphine and did not systematically their patients of the therapeutic aims. CONCLUSION: Greater awareness by the practitioners of palliative care would help to improve the quality of care supplied to terminally ill patients.

X-ray structure of HPr kinase: a bacterial protein kinase with a P-loop nucleotide-binding domain.

HPr kinase/phosphatase (HprK/P) is a key regulatory enzyme controlling carbon metabolism in Gram- positive bacteria. It catalyses the ATP-dependent phosphorylation of Ser46 in HPr, a protein of the phosphotransferase system, and also its dephosphorylation. HprK/P is unrelated to eukaryotic protein kinases, but contains the Walker motif A characteristic of nucleotide-binding proteins. We report here the X-ray structure of an active fragment of Lactobacillus casei HprK/P at 2.8 A resolution, solved by the multiwavelength anomalous dispersion method on a seleniated protein (PDB code 1jb1). The protein is a hexamer, with each subunit containing an ATP-binding domain similar to nucleoside/nucleotide kinases, and a putative HPr-binding domain unrelated to the substrate-binding domains of other kinases. The Walker motif A forms a typical P-loop which binds inorganic phosphate in the crystal. We modelled ATP binding by comparison with adenylate kinase, and designed a tentative model of the complex with HPr based on a docking simulation. The results confirm that HprK/P represents a new family of protein kinases, first identified in bacteria, but which may also have members in eukaryotes.