947 resultados para Serum.


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Serum-free aggregating brain cell cultures are free-floating three-dimensional primary cell cultures able to reconstitute spontaneously a histotypic brain architecture to reproduce critical steps of brain development and to reach a high level of structural and functional maturity. This culture system offers, therefore, a unique model for neurotoxicity testing both during the development and at advanced cellular differentiation, and the high number of aggregates available combined with the excellent reproducibility of the cultures facilitates routine test procedures. This chapter presents a detailed description of the preparation, maintenance, and use of these cultures for neurotoxicity studies and a comparison of the developmental characteristics between cultures derived from the telencephalon and cultures derived from the whole brain. For culture preparation, mechanically dissociated embryonic brain tissue is used. The initial cell suspension, composed of neural stem cells, neural progenitor cells, immature postmitotic neurons, glioblasts, and microglial cells, is kept in a serum-free, chemically defined medium under continuous gyratory agitation. Spherical aggregates form spontaneously and are maintained in suspension culture for several weeks. Within the aggregates, the cells rearrange and mature, reproducing critical morphogenic events, such as migration, proliferation, differentiation, synaptogenesis, and myelination. For experimentation, replicate cultures are prepared by the randomization of aggregates from several original flasks. The high yield and reproducibility of the cultures enable multiparametric endpoint analyses, including "omics" approaches.

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OBJECTIVE: Glycodelin (PP14) is produced by the epithelium of the endometrium and its determination in the serum is used for functional evaluation of this tissue. Given the complex regulation and the combined contraceptive and immunosuppressive roles of glycodelin, the current lack of normal values for its serum concentration in the physiological menstrual cycle, derived from a large sample number, is a problem. We have therefore established reference values from over 600 sera. DESIGN: Retrospective study using banked serum samples. SETTING: University hospital. METHODS: Measurement of blood samples daily or every second day during one full cycle. MAIN OUTCOME MEASURES: Serum concentrations of glycodelin and normal values for every such one- or two-day interval were calculated. Late luteal phase glycodelin levels were compared with ovarian hormones. Follicular phase levels were compared with stimulated cycles from patients undergoing in vitro fertilization. RESULTS: Glycodelin concentrations were low around ovulation. Highest levels were observed at the end of the luteal phase; the glycodelin serum peak was reached 6-8 days after the one for progesterone. Late luteal glycodelin levels correlated negatively with the body mass index and positively with the progesterone level earlier in the secretory (mid-luteal) phase in the same woman. No associations with other ovarian hormones were observed. Follicular phase glycodelin levels were higher in the spontaneous than in the in vitro fertilization cycles. CONCLUSIONS: Normal values taken at two- or one-day intervals demonstrate the very late appearance of high serum glycodelin levels during the physiological menstrual cycle and their correlation with progesterone occurring earlier in the cycle.

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Aggregate cultures of mixed glial cells, as well as of enriched astrocytes and oligodendrocytes were prepared, and maintained in serum-free medium for up to 25 days. Biochemical measurements of both neuron-specific and glia-specific enzyme activities showed that these three types of aggregate cultures were virtually devoid of neurons. Astrocyte-enriched cultures were greater than 95% pure, with oligodendrocytes as the only apparent contaminant, whereas oligodendrocyte-enriched cultures still contained a considerable proportion of astrocytes. In all these neuron-free aggregate cultures both astrocytes and oligodendrocytes attained a high degree of maturation. These findings were confirmed by morphological examinations, and by immunofluorescence studies. Furthermore, ultrastructural as well as immunocytochemical investigations using antibodies to myelin basic protein revealed that all three types of glial cell aggregate cultures contained myelin membranes, indicating that the presence of axons is not a prerequisite for the formation of myelin.

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We explored the washout period of creatine (Cr) after repeated ingestions of high doses of exogenous Cr. Ten athletes ingested daily, in a randomized double-blind study design, 30 g of exoge- nous Cr (n = 5, Cr-group) or a placebo (n = 5, Pl-group). Serum and urine samples were collected 1) before supplementation (BEFO- RE), 2) after one week Cr supplementation (AFTER), and 3) one week later without supplementation (LATER). The Cr and crea- tinine (Crn) concentrations in serum (sCr, sCrn) and in multiple spots urine (uCr, uCrn) were measured. We observed a significant rise (p < 0.01) in sCr, uCr and sCrn between BEFORE and AFTER supplementation in Cr-group, as well as a significant difference between Cr-group and Pl-group. Body weight increased signifi- cantly (+1.5 kg), but relative body fat (%fat) was unchanged. After the washout period in LATER Cr-group, sCr and uCr decreased to low residual values. No loss of body weight occurred during thisperiod. In contrast, sCrn and uCrn returned to baseline values. In conclusion, regular uptake of high doses of exogenous Cr affects both Cr and Crn concentrations in serum (sCr: 14 folds; sCrn: 1.2 folds) and urine (uCr: 140 folds; uCrn: 1.5 folds). An abuse of Cr is therefore mostly spilled over in urine. Surprise drug tests, such as doping controls, happening during the period of Cr supplementa- tion can reveal an important increase in Cr and Crn concentrations, although subjects stopped suddenly Cr loading. The discernible effect of Cr supplementation on these values disappeared within one week.

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Introduction: Small for gestational age (SGA) is an important problem affecting 10% of pregnancies and is associated with significant perinatal morbidity. In about 80% of cases, a probable etiology or a major risk factor can be identified. But almost 20% of SGA cases are considered unexplained. The 60-kDa heat shock protein (HSP60) is a highly immunogenic protein whose synthesis is greatly upregulated under nonphysiological conditions. Bacterial and human HSP60 share a high degree of sequence homology, and immunity to conserved epitopes may result in development of autoimmunity following a bacterial infection. We hypothesized that unexplained SGA could be the consequence of immune sensitization to human HSP60. Methods: Unexplained SGA fetuses were identified by ultrasound biometry with normal Doppler velocimetry and with no detectable maternal or fetal abnormalities. Fetal sera were obtained by cordocentesis performed for a karyotype analysis in cases of unexplained SGA (study group) or for screening of Rhesus incompatibility (control group). Fetal sera were tested for HSP60 antigen and for IgG and IgM anti-HSP60 by ELISA as well as for other immune and hematological parameters. Results: Maternal parameters were similar between the 12 study cases and the 23 control cases. The mean gestational age at cordocentesis was 29 weeks. IgM anti-HSP60 was detected in 12 cases (100%) and in no controls (p < 0.00017), while IgG anti-HSP60 was detected in 7 cases (58%) and only 1 control (p < 0.001). Three of the 4 cases with the highest IgM antibody levels died. There were no differences in fetal serum levels of HSP60 antigen or other immune and hematological markers between the two groups. Conclusion: Fetuses with unexplained SGA are positive for IgM and IgG antibody to human HSP60 and the specific IgM antibody level is predictive of fetal mortality. Detection of these antibodies indicates that a placental perturbation and a fetal autoimmune reaction to HSP60 are associated with this developmental delay.

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Purpose: Plasma adiponectin and serum uric acid (SUA) levels are negatively correlated. To better understand the possible mechanisms linking adiponectin and uric acid, we analyzed whether the association between adiponectin and SUA differed by hypertension status (or blood pressure level) and by sex. Methods and materials: We analyzed data from the populationbased CoLaus study (Switzerland). Fasting plasma adiponectin levels were assessed by ELISA and SUA by uricase-PAP. Blood pressure (BP) was measured using a validated automated device and hypertension was defined as having office BP 140/90 mm Hg or being on current antihypertensive treatment. Results: In the 2897 men and 3181 women, aged 35-74, BMI (mean ± SD) was 26.6 ± 4.0 and 25.1 ± 4.8 Kg/m2, systolic blood pressure (SBP) was 132.2 ± 16.6 and 124.8 ± 18.3 mm Hg, median (interquartile range) plasma adiponectin was 6.2 (4.1-9.2) and 10.6 (6.9-15.4) mg/dL, and hypertension prevalence was 42.0% and 30.2%, respectively. The age- and BMI- adjusted partial correlation coefficients between log-adiponectin and SUA were 0.09 and 0.06 in normotensive men and women (P <0.01), and 0.004 (P = 0.88) and 0.15 (P <0.001) in hypertensive men and women, respectively. In median regression adjusted for BMI, insulin, smoking, alcohol consumption, menopausal status and HDL-cholesterol, there was a significant three-way interaction between SUA, SBP and sex for their effect on adiponectin (dependent variable, P = 0.005), as well as interactions between SBP and sex (P = 0.014) and between SUA and sex (P = 0.033). Conclusion: Plasma adiponectin and SUA are negatively associated, independently of BMI and insulin, in a population-based study in Caucasians. However, BP modifies this inverse relationship, as it was significant mainly in women with elevated BP. This observation suggests that the link between adiponectin and SUA may be mediated by sex hormones and the hypertension status.

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Background: Limited information exists regarding the association between serum uric acid (SUA) and psychiatric disorders. We explored the relationship between SUA and subtypes of major depressive disorder (MDD) and specific anxiety disorders. Additionally, we examined the association of SLC2A9 rs6855911 variant with anxiety disorders. Methods: We conducted a cross-sectional analysis on 3,716 individuals aged 35-66 years previously selected for the population-based CoLaus survey and who agreed to undergo further psychiatric evaluation. SUA was measured using uricase-PAP method. The French translation of the semi-structured Diagnostic Interview for Genetic Studies was used to establish lifetime and current diagnoses of depression and anxiety disorders according to the DSM-IV criteria. Results: Men reported significantly higher levels of SUA compared to women (357}74 μmol/L vs. 263}64 μmol/L). The prevalence of lifetime and current MDD was 44% and 18% respectively while the corresponding estimates for any anxiety disorders were 18% and 10% respectively. A quadratic hockey-stick shaped curve explained the relationship between SUA and social phobia better than a linear trend. However, with regards to the other specific anxiety disorders and other subtypes of MDD, there was no consistent pattern of association. Further analyses using SLC2A9 rs6855911 variant, known to be strongly associated with SUA, supported the quadratic relationship observed between SUA phenotype and social phobia. Conclusions: A quadratic relationship between SUA and social phobia was observed consistent with a protective effect of moderately elevated SUA on social phobia, which disappears at higher concentrations. Further studies are needed to confirm our observations.

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Mast cells are well known for their role in hypersensitivity reactions. However, there is increasing evidence that they might also participate in both developing and weakening atherosclerotic plaques, potentially causing plaque instability. Some clinical studies have therefore postulated the existence of relationships between blood β-tryptase levels and acute coronary syndromes. In this study, we investigated postmortem serum β-tryptase levels in a series of 90 autopsy cases with various degrees of coronary atherosclerosisthat had undergone medico-legal investigations. β-tryptase concentrations in these cases were compared to levels observed in 6 fatal anaphylaxis cases following contrast material administration. Postmortem serum β-tryptase concentrations in the anaphylactic deaths ranged from 146 to 979 ng/ml. In 9 out of 90 cases of cardiac deaths, β-tryptase levels were higher than clinical reference values of 11.4 ng/ml and ranged from 21 to 65 ng/ml. These results indicate that increased postmortem serum β-tryptase levels can be observed, though not systematically, in cardiac deaths with varying degrees of coronary atherosclerosis disease, thereby suggesting that mast cell activation in this disease cannot be ascertained by postmortem serum β-tryptase measurements.

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Leishmania promastigotes polypeptides are analyzed by immunoblotting with sera from patients infected with different Leishmania species and presenting visceral or cutaneous infections. These sera recognize Leishmania polypeptides in several molecular masses. The major findings of this study are as follow. 1) The Leishmania 94 kDa antigen, which is specifically recognized by all sera from L. infantum-infected patients with visceral infection, is recognized by some sera from L. infantum-infected patients presenting cutaneous infection. 2) All patients with cutaneous infections due to L. tropica, L. amazonensis, or L. guyanensis do not develop anti-94 kDa antibodies, whatever the Leishmania species used as antigens. 3) Difference in electrophoretic mobilities is seen between the 94 kDa antigen identified by sera from Leishmania infantum-infected patients, and the antigen both recognized by the Concavalin A lectin and a rabbit antiserum raised against deglycosylated Promastigote Surface Protease.

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OBJECTIVE: Resistin is associated with inflammation and insulin resistance and exerts direct effects on myocardial cells including hypertrophy and altered contraction. We investigated the association of serum resistin concentrations with risk for incident heart failure (HF) in humans. METHODS AND RESULTS: We studied 2902 older persons without prevalent HF (age, 73.6+/-2.9 years; 48.1% men; 58.8% white) enrolled in the Health, Aging, and Body Composition (Health ABC) Study. Correlation between baseline serum resistin concentrations (20.3+/-10.0 ng/mL) and clinical variables, biochemistry panel, markers of inflammation and insulin resistance, adipocytokines, and measures of adiposity was weak (all rho <0.25). During a median follow-up of 9.4 years, 341 participants (11.8%) developed HF. Resistin was strongly associated with risk for incident HF in Cox proportional hazards models controlling for clinical variables, biomarkers, and measures of adiposity (HR, 1.15 per 10.0 ng/mL in adjusted model; 95% CI, 1.05 to 1.27; P=0.003). Results were comparable across sex, race, diabetes mellitus, and prevalent and incident coronary heart disease subgroups. In participants with available left ventricular ejection fraction at HF diagnosis (265 of 341; 77.7%), association of resistin with HF risk was comparable for cases with reduced versus preserved ejection fraction. CONCLUSIONS: Serum resistin concentrations are independently associated with risk for incident HF in older persons.

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Rapport de synthèse : Objectif de l'étude : étudier si l'administration orale ou vaginale d'hormones contraceptives influence les concentrations sériques d'hormone antimüllérienne (AMH). Design : essai prospectif chez des femmes recrutées par annonce. Les femmes désireuses d'avoir une contraception ont été randomisées entre une contraception orale et une contraception vaginale. Celles qui ne souhaitaient pas de contraception ont été incluses dans le groupe témoin. Cadre de l'étude : unité de médecine de la reproduction d'un hôpital universitaire. Patientes : vingt-quatre jeunes femmes en bonne santé avec des cycles menstruels réguliers qui n'avaient pas utilisé de contraception hormonale pendant les trois mois précédant l'étude. Intervention : contraception orale ou vaginale du 5ème au 25ème jour du cycle menstruel dans les groupes contraception versus pas de contraception dans le groupe témoin. Mesure d'issue : variations inter et intra-cycle des concentrations sériques d'AMH dans les trois groupes: groupe témoin en cycle spontané et groupes sous contraception oestroprogestative orale ou vaginale. Résultats : les fluctuations d'AMH observées pendant le cycle menstruel (variations intra-cycle) restent dans les valeurs des variations entre deux cycles (variations inter-cycles) tant chez les femmes en cycle spontané que chez les femmes sous contraception orale ou vaginale. Conclusions : nos résultats confirment que les concentrations sériques d'AMH restent stables pendant le cycle menstruel et indiquent qu'elles ne sont pas influencées par l'administration exogène de stéroïdes sexuels contraceptifs, que ce soit par voie orale ou vaginale.

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The aim of the study was to explore the effect of an acute dose of creatine (Cr) ingestion on serum Cr and serum creatinine (Crn) concentrations. Sixteen healthy subjects ingested a single dose of Cr (20 g) followed by the measurement of serum Cr and Crn concentration for 3 h up to a maximum of 6 h (n=6). In response to Cr ingestion a large rise in serum Cr concentration was observed (by 50 folds) occurring approximately 2 1/2h after the ingestion (peak value of 2.17 +/- 0.66 mmol x l(-1)). We also found a moderate but significant rise in serum Crn concentration averaging 13 % after 3 h (peak value at 99.5 +/- 10.5 micromol x l(-1)). A dose response curve obtained in two case studies, in whom different doses of Cr were ingested (0, 2.5, 5, 10, 15, 20 g and 0, 10, 20, 30 g), showed that serum Cr concentration as well as the peak time increased linearly with Cr ingestion. In addition, acute Crn ingestion (5 g) resulted in a substantial increase in serum Crn concentration (by 10 folds) but led to a minor rise in serum Cr concentration (by 2 folds). These results suggest that when acute doses of Cr are ingested in humans, the degree of conversion of exogenous Cr to Crn in the stomach and the gut can be considered as negligible following the first 6 h of ingestion. However, further studies are required to explore the prolonged effect of Cr on Crn metabolism.

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First trimester biochemical trisomy screening is based on serum concentrations of pregnancy-associated plasma protein A (PAPP-A) and human chorionic gonadotrophin (hCG). Our aim was to confirm previously suggested modifications in serum marker concentrations after in vitro fertilisation (IVF) and embryo transfer (ET), and to assess the need of establishing normal medians for trisomy screening in these. We compared 56 singleton pregnancies obtained after ET (of which 40 in gonadotrophin stimulation cycles) with 120 gestation-matched spontaneous controls. For multiple pregnancies, 17 treated cycles were compared with 25 controls. The levels of PAPP-A, hCG, and pregnancy-specific β1-glycoprotein were determined and compared between treated and spontaneous pregnancies. Serum PAPP-A levels were reduced in pregnancies achieved after gonadotrophin-stimulated IVF and ET, and this was more pronounced in earlier gestational stages. SP1 followed the same trend, while hCG tended to be increased, and this not only in pregnancies obtained from gonadotrophin-stimulated but also from oestrogen supported cycles, and with a more pronounced effect in the later gestational ages examined here. Decreased PAPP-A together with increased hCG concentrations produce falsely elevated results in first trimester Down syndrome screening, but we do not recommend the establishment of normal medians for IVF pregnancies due to the variations in stimulation protocols.