Postinjury complement C4 activation is associated with adverse outcomes and is potentially influenced by plasma resuscitation

BACKGROUND

Complement activation after trauma promotes hemostasis but is associated with increased morbidity and mortality. However, the specific pathways and downstream mediators remain unclear. Recently, the anaphylatoxin C4a has been shown to bind to thrombin receptors. While plasma-based resuscitation has been shown to modify the endotheliopathy of trauma, it may provide complement zymogens that fuel ongoing inflammatory cascades. We sought to characterize the activation of complement after injury and the effect of fresh frozen plasma (FFP) on this inflammatory response. We hypothesized that trauma induces C4 activation, which is associated with worse outcomes and influenced by FFP resuscitation.

METHODS

Blood was collected from injured patients at a single level I trauma center enrolled in the Control of Major Bleeding after Trauma (COMBAT) randomized clinical trial. Proteomic analyses were performed through targeted liquid chromatography coupled with mass spectrometry. For the present observational study, concentrations of complement proteins were analyzed at multiple time points, compared between treatment groups, and correlated with outcomes.

RESULTS

C4 activation occurred over the first 6 hours postinjury with peak activation 6 to 24 hours. Tissue hypoperfusion, defined as base deficit >10 mEq/L, and requirement for massive transfusion were associated with greater C4 activation. C4 activation was associated with mortality, multiple organ failure, and longer ventilator requirement. In addition, temporal trends of C1q, factor B, and C3 by outcome groups support the prevailing theory of primary classical pathway activation with alternative pathway amplification. Resuscitation with FFP over the first 6 hours was associated with increased C4 activation at 12 and 24 hours.

CONCLUSION

C4 activation has an important inflammatory role postinjury, and FFP has the potential to augment this complement activation during resuscitation.

LEVEL OF EVIDENCE

Prognostic/epidemiological, level III.

Medication exposure and spontaneous abortion: a case-control study using a French medical database

PURPOSE OF INVESTIGATION

Few studies have been conducted to investigate drug effects on spontaneous abortion risk. The objective of the present study was to evaluate the potential association between first trimester drug exposure and spontaneous abortion occurrence.

MATERIALS AND METHODS

The authors performed a nested case-control study using data from TERAPPEL, a French medical database. Cases were the women who had a spontaneous abortion (before the 22nd week of amenorrhea) and controls were women who gave birth to a child. Analyzed variables were: maternal age, obstetric history, tobacco, and alcohol and drug consumption during the first trimester of pregnancy. For comparison of drug exposures between cases and controls, the authors calculated odds ratios (ORs) by means of multivariate logistic regressions adjusted on age and on other drug exposures.

RESULTS

The study included 838 cases and 4,508 controls that were identified in the database. In adjusted analyses, cases were more exposed than controls to "non-selective monoamine reuptake inhibitors" [OR=2.2 (CI 95% 1.5-3.3)], "antiprotozoals" [OR = 1.6 (CI 95% 1.1 - 2.5)] and "centrally acting antiobesity products" [OR = 3.4 (CI 95% 1.9 - 6.2)]. Conversely, controls were more exposed than cases to H1 antihistamines [OR = 0.6 (CI 95% 0.4 - 0.9)].

CONCLUSION

This exploratory study highlights some potential associations between first trimester drug exposure and risk of spontaneous abortion. Further studies have to be carried out to investigate these findings.

Safety of oseltamivir during pregnancy: a comparative study using the EFEMERIS database

OBJECTIVE

To compare pregnancy outcome between women exposed and unexposed to oseltamivir during pregnancy.

DESIGN

A comparative observational cohort study of women exposed to oseltamivir during pregnancy.

SETTING

A French prescription database (EFEMERIS) that includes data for pregnant women was used. EFEMERIS records prescribed and dispensed reimbursed drugs during pregnancy and pregnancy outcomes in Haute-Garonne, South West France.

POPULATION

Women who delivered from 1 July 2004 to 31 December 2010.

METHODS

The study compared exposed and unexposed pregnant women. Two women unexposed to oseltamivir were individually matched, by maternal age, month, and year of delivery, with one women exposed to oseltamivir. Multivariable conditional logistic regression and multivariable Cox proportional hazards regression were used to evaluate associations between each outcome and exposure to oseltamivir during pregnancy.

MAIN OUTCOME MEASURES

Pregnancy loss for any cause, preterm delivery, low birthweight, neonatal pathology, and congenital malformation.

RESULTS

A cohort of 337 (0.58% of women included in EFEMERIS) women exposed to oseltamivir were compared with 674 unexposed women. The risk for pregnancy loss (HR 1.52; 95% CI 0.80-2.91), for preterm birth (adjusted OR 0.64; 95% CI 0.31-1.27), and for neonatal pathology (adjusted OR 0.62; 95% CI 0.23-1.54) did not differ between exposed and unexposed groups. When exposure during organogenesis was considered, one case of congenital anomaly (2.0%) among 49 exposed women and one case (1.0%) among 99 unexposed women were observed (crude OR 2.00; 95% CI 0.13-32.00).

CONCLUSIONS

There was no significant association between adverse pregnancy outcomes and exposure to oseltamivir during pregnancy.

Pandemic A/H1N1 influenza vaccination during pregnancy: a comparative study using the EFEMERIS database

OBJECTIVE

To evaluate the risk of adverse pregnancy outcomes following A/H1N1 vaccination in pregnant women.

METHODS

This observational cohort study compared vaccinated and non-vaccinated pregnant women in EFEMERIS, a French prescription database including pregnant women. Women who ended their pregnancy in South Western France between October 21, 2009 and November 30, 2010 (the period of the French vaccination campaign) were included. Two non-vaccinated women were individually matched to each vaccinated woman by month and year of pregnancy onset. Conditional logistic regression and Cox proportional hazards regression were used to evaluate associations between each outcome (all-cause pregnancy loss, preterm delivery, small for gestational age (SGA) and neonatal pathology) and A/H1N1 vaccination during pregnancy.

RESULTS

1645 women of the 12,120 (13.6%) in the database who were administered A/H1N1 vaccine during pregnancy were compared to 3290 non-vaccinated women. Most were vaccinated in December 2009 (61%) with a non-adjuvanted vaccine (93%). The risks of pregnancy loss (adjusted HR=0.56; 95% CI=0.31-1.01), of preterm birth (adjusted HR=0.82; 95% CI=0.64-1.06), and of neonatal pathology (adjusted OR=0.70; 95% CI=0.49-1.02) did not differ between the vaccinated and the non-vaccinated groups. The rate of SGA was lower in the vaccinated group than in the non-vaccinated group (0.5% vs. 1.4%; adjusted OR=0.36; 95% CI=0.17-0.78).

CONCLUSION

There was no significant association between adverse pregnancy outcomes and vaccination with a non-adjuvanted A/H1N1 vaccine during pregnancy.

[First epidemiologic data about phloroglucinol exposure during first trimester of pregnancy]

OBJECTIVE

Phloroglucinol is used to prevent gastric, intestine or urogenital spasms. In France, many pregnant women are exposed to phloroglucinol for which no data are available about its use in pregnancy. The present study, using EFEMERIS database, investigates potential teratogenic risk of phloroglucinol in pregnancy.

MATERIALS AND METHODS

EFEMERIS is a database including prescribed and delivered drugs during pregnancy (data from Caisse Primaire d'Assurance Maladie of Haute-Garonne) and outcomes (data from Maternal and Infant Protection Service and from Antenatal diagnostic Centre). Women delivered from July 1st 2004 to June 30th 2008 in Haute-Garonne and registered in the French Health Insurance Service were included into EFEMERIS database. We compared pregnancy outcomes and newborn health between women exposed to phloroglucinol during organogenesis and non-exposed women. Malformations were classified according to Eurocat classification.

RESULTS

Five thousand one hundred and thirty-two newborns (12.7%) exposed during organogenesis to phloroglucinol were compared to 35,223 controls (non exposed newborns). The mean number of different drugs prescribed during the first trimester of pregnancy per woman was higher in women exposed to phloroglucinol than in non-exposed women (6.4 ± 4.3 versus 2.4 ± 3.3, P < 10(-4)). Among newborns, 126 (2.5%) had a malformation versus 804 (2.3%) in control newborns (OR=1.1, [0.9-1.3]). The present study was powered to find a 1.3 fold increase in the overall rate of major anomalies.

DISCUSSION AND CONCLUSION

This first epidemiologic study about phloroglucinol in pregnancy does not support evidence of a teratogenic risk for phloroglucinol in humans.

Dépistage de la trisomie 21 par le test combiné du premier trimestre suivi par l'échographie du second trimestre en population générale

BACKGROUND

Recent studies have reported the efficacy of first trimester combined screening for Down Syndrome based on maternal age, serum markers (human chorionic gonadotropin, pregnancy-associated plasma protein A), and ultrasound measurement of fetal nuchal translucency. However, those do not incorporate the value of the widely accepted routine 20-22 week anomaly scan.

STUDY DESIGN

We carried out a multi-centre, interventional study in the unselected population of a single health authority in order to assess the performance of first trimester combined screening, followed by routine second trimester ultrasound examination and/or screening by maternal serum markers (free beta-hCG and alpha-fetoprotein measurement or total hCG, alpha-fetoprotein and unconjugated estriol measurement) when incidentally performed. Detection and screen positive rates were estimated using a correction method for non verified issues. A cost analysis was also performed.

RESULTS

During the study period, 14,934 women were included. Fifty-one cases of Down Syndrome were observed, giving a prevalence of 3.4 per 1000 pregnancies. Of these, 46 were diagnosed through first (N=41) or second (N=5) trimester screening. Among the 5 screen-negative Down syndrome cases, all were diagnosed postnatally after an uneventful pregnancy. Detection and screen positive rates of first trimester combined screening were 79.6% and 2.7%, respectively. These features reached 89.7 and 4.2%, respectively when combined with second trimester ultrasound screening. The average cost of the full screening procedure was 108 euro (120 $) per woman and the cost per diagnosed Down syndrome pregnancy was 7,118 euro (7,909 $).

CONCLUSION

Our findings suggest that one pragmatic interventional two-step approach using first-trimester combined screening followed by second trimester detailed ultrasound examination is a suitable and acceptable option for Down syndrome screening in pregnancy.

[Myocardial infarction in a young female smoker taking oral contraception]

A 33 year old woman suffered a lateral myocardial infarction for the first time, and was treated by pre-hospital thrombolysis and secondary angioplasty on the diagonal artery. Fifteen days before the cardiac event she had undergone a left ovarian cyst excision and left salpingectomy for an ectopic pregnancy. She was a moderate smoker and had been taking a second-generation biphasic minidose oral contraceptive (ethinyl-estradiol 30-40mg and levonorgestrel 150-200 mg) for about ten years. Fifteen days before the myocardial infarction and due to the ectopic pregnancy she had changed to a combined monophasic minidose oral contraceptive pill containing ethinylestradiol (30 mg) and drospirenone (3 mg). The eventual outcome was favourable, with no complications. In this article we discuss the possible implications of the various factors (oral contraceptive, tobacco use, and surgical intervention) in this young woman with a myocardial infarction.

Nonsteroidal anti-inflammatory drug-induced liver injury: a case-control study in primary care

Several nonsteroidal anti-inflammatory drugs (NSAIDs) have been withdrawn from the market because of hepatic adverse drug reactions (ADRs). Moreover, some cases of liver diseases have been reported in patients taking NSAIDs (arylcarboxylic NSAIDs, piroxicam, sulindac, nimesulide, etc.). Pharmacoepidemiological studies have shown a risk of hepatic ADRs with NSAIDs used in association with other hepatotoxic drugs. In contrast, other studies performed in hospitalized patients did not found any association. The aim of this study was to assess the hepatic risk associated with the use of NSAID in the setting of primary care. The study design was a case-control study where cases and controls were all recruited among patients seen in the context of medical community care. Eighty-eight cases and 178 controls were included between January 1998 and December 2000. Cases used more drugs than controls in the 15 days before index day (2.9 +/- 2.2 vs. 1.8 +/- 1.8 different consumed drugs; P < 10(-4)). After adjustment, we found a significant association between liver injury and NSAID exposure in women [odds ratio (OR) = 6.49 (1.67-25.16)] but not in men [OR = 1.06 (0.36-3.12)]. A total of 22 cases were exposed to NSAIDs. Of them, seven patients were exposed to salicylates, five to diclofenac, four to ibuprofen, four to ketoprofen, two to niflumic acid, one to flurbiprofen and one to meloxicam (two patients were simultaneously exposed to two different NSAIDs: salicylate + niflumic acid and salicylate + diclofenac). These patients suffered from hepatocellular (53.3%), cholestatic (20%) or mixed (26.7%) injury. In 18 cases, liver enzymes returned to normal values after discontinuation of drug. No case had a fatal outcome. This study shows the existence of a significant association between liver disturbances and NSAID use in women.

Buprenorphine in pregnant opioid-dependent women: first results of a prospective study

AIM

To report results on the prospective follow-up of 34 pregnant women exposed to buprenorphine maintenance for opiate dependence.

DESIGN AND SETTING

Prospective multicentre study: all pregnant women receiving buprenorphine as maintenance therapy were included as early as possible during their pregnancy.

PARTICIPANTS

The pregnant women were recruited from opiate maintenance therapy centres, general practitioner-networks involved in addiction, maternity hospitals and centres for drug information during pregnancy.

MEASUREMENTS

Women: drugs and medications consumed, medical and obstetrical events; offspring: withdrawal syndrome, malformation, neonatal disease.

FINDINGS

The buprenorphine-exposed pregnancies resulted in 31 live births, one stillbirth, one spontaneous abortion and one voluntary termination. A neonatal withdrawal syndrome was observed in 13 cases (41.9%) and eight of these babies required opiate treatment. Two neonates had a malformation: a premature ductus arteriosus stricture and a tragus appendix.

CONCLUSION

Taken together with other prospective studies, no alarming results were observed concerning pregnancy outcomes. However, further data from the comparative prospective study are required to determine whether buprenorphine can be considered as a good alternative to methadone treatment in pregnant women.

Comparison of progesterone concentration determination by 12 non-isotopic immunoassays and gas chromatography/mass spectrometry in 99 human serum samples

A single serum progesterone determination may be highly predictive for early pregnancy and in vitro fertilisation and embryo-transfer outcomes. We therefore compared 12 direct non-isotopic progesterone immunoassays with gas-chromatography/mass spectrometry (GC/MS). For each assay, data from the analysis of 99 individual sera were compared with data obtained by GC/MS, using regression and bias plot analyses and the ratio method. We observed a larger difference in concentration between high and low values and a broader distribution of results for immunoassays than for GC/MS. All immunoassays displayed bias in the calibration process and a lack of specificity and/or sensitivity, to various degrees. We tried to identify the parameters of the assay procedure that might contribute to these discrepancies. None of the criteria investigated (antibodies, control and preparation of calibrators, blocking agents and choice of tracer) had a significant effect when studied alone.

[Follow-up of 'medications and pregnancy' at the Midi-Pyrenees Pharmacovigilance Center']

The follow-up of 283 gestations recorded by the Midi-Pyrénées Pharmacovigilance Centre concerned 544 medications, 17 solvents and 12 illicit drugs. Pregnancy outcomes were live births for 74.2 per cent of the women and voluntary (14.8 per cent), spontaneous (8.5 per cent) or therapeutic (1.8 per cent) abortions. Among the newborns, 11 had a malformation and 18 a neonatal disease. We observed an increased risk of neonatal disease for women exposed to illicit drugs during the third trimester of their pregnancy (OR = 14.28 [1.19-747.40] p = 0.0155) and for smokers (OR = 19.11 [2.11-445.00] p = 0.0011). Moreover, an increase of teratogenic risk was associated with a first trimester exposure to neurologic drugs (OR = 14.28 [2.08-100.00] p = 0.006). Women included in the present survey were more often exposed to potentially harmful drugs than the general population. However, the rates of obstetric and/or neonatal complications appear similar to those reported in France as a whole.

Prescription of drugs during pregnancy in France

A survey of the records of the French Health Insurance Service of drug prescriptions during pregnancy in 1000 women living in Haute-Garonne, southwest France, showed that 99% of the women received a prescription for at least one drug during pregnancy with a mean of 13.6 medications per woman. 1.6% of women received one or more prescriptions of drugs from the US Food and Drug Administration X category (fetal risk outweighs benefits). 59% of women had a prescription of drugs from the D category (fetal risk but benefits may be acceptable) and 79% of women were exposed to drugs for which information about safety in pregnancy was not available from animal or human studies.

Microbial models of drug metabolism: microbial transformations of Trimegestone (RU27987), a 3-keto-delta(4,9(10))-19-norsteroid drug

Screening microorganisms for the biotransformation of the 3-keto-delta(4,9(10))-19-norsteroid RU27987 (Trimegestone) resulted in the isolation of nine identified metabolites, some of them being selectively produced by different strains. Eight metabolites were found to be hydroxylated on various positions of the rings, and one was additionally epoxidized. These microbial metabolites could be used as chromatographic standards and two of them were found identical to the unknown major human metabolites. Moreover, most microbial metabolites were produced in sufficient amounts to be tested for their biological activities. All these features demonstrate the usefulness and versatility of microbial biotransformation systems as a tool for early identification and convenient production of potentially active mammalian and non-mammalian metabolites.

Differential signaling of human Mel1a and Mel1b melatonin receptors through the cyclic guanosine 3'-5'-monophosphate pathway

Cyclic guanosine 3'-5'-monophosphate (cGMP) has recently been shown to constitute a second messenger for Xenopus laevis melatonin Mel1c receptors. To verify whether cGMP levels are also modulated by mammalian melatonin receptors, we cloned the genes encoding the human Mel1a and Mel1b receptor subtypes and expressed them in human embryonic kidney cells. Pharmacological profiles and inhibition of forskolin-stimulated adenosine 3'-5'-cyclic monophosphate levels by melatonin confirmed functional expression of high-affinity melatonin receptors. Mel1b receptor-transfected cells modulated cGMP levels in a dose-dependent manner via the soluble guanylyl cyclase pathway. In contrast, Mel1a receptors had no effect on cGMP levels. These results demonstrate that mammalian melatonin receptors modulate cGMP levels and reveal for the first time differences in signaling between melatonin receptor subtypes, which may explain the necessity to express different receptor subtypes.

[Validity of immunochemical methods for bloody progesterone: a study performed in 1998]

The aim of this study was to compare, with manufacturer's agreement, twelve direct and non-isotopic commercial assays of progesterone. We have evaluated the analytical performances: low limit detection, imprecision, accuracy (recovery and dilution tests) and we have tested some patient samples. Results were compared to a reference method using isotope dilution Gas Chromatography and Mass Spectrometry combination (GC-MS). For each assay, analytical qualities and defaults are established. Large differences are found between progesterone concentration measured on the same sample with the different methods essentially for the low concentrations. Comparison with GC-MS raised questions about the accuracy of the different assays. This work will be aid laboratories to their choice and/or validation.

[Pregnancy and perinatality: biological follow-up]

Blood and urinary tests which are necessary for pregnancy diagnosis and follow-up, for newborn and mother medical supervision, during the month following birthday, are today described in reglementary texts, laws, and recommendations such as advised medical references (RMO). These documents specify the nature of obligatory tests, the checking rhythm and the list of useless tests. hCG research remains necessary for pregnancy diagnosis, but hCG dosage is essential only in case of programmed medical assistance or pathological pregnancy (extrauterine pregnancy, hydatiform mole, choriocarcinoma). The obligatory follow-up of a pregnant woman includes determination of blood groups, research of infectious agents responsible for diseases (toxoplasmosis, rubeola, hepatitis B, syphilis), proteinuria and glycosuria research and blood count according to a given calendar. When the mother's condition is bad and reminiscent of a pathological pregnancy, when a genetic risk exists for the fetus or when fetal growth is abnormal as indicated by echographic control (intra-uterine growth retardation), laboratory tests are used to follow the maternal pathological course (arterial hypertension, diabetes mellitus, anemia, bacterial, viral or parasitic disease), to verify the existence of a genetic disease, to know about the fetal functional state (by amniocentesis or cordocentesis), to identify an erythrocyte fetomaternal incompatibility. Since last trimester pregnancy accidents are able to endanger mother's and fetus lives, the feto-maternal follow-up must be adjusted to pathological diagnosis types and requires a particular supervision of the delivery. Finally mother and child must undergo a post-natal follow-up during the four weeks after birthday (perinatality control).

Novel isoforms of Mel1c melatonin receptors modulating intracellular cyclic guanosine 3',5'-monophosphate levels

Two cDNAs encoding novel isoforms of Xenopus laevis melatonin receptors were cloned using PCR primers specific for the X. laevis-melanophore Mel1c melatonin receptor described in a recent publication. The novel isoforms were highly homologous to the described frog Mel1c cDNA, although the C-terminal tail of both was shorter by 65 amino acid residues. Nucleotide sequences of these novel isoforms, called Mel1c(alpha) and Mel1c(beta), differed from each other by only 35 nucleotides and six amino acid residues. Studies on several animals of various Xenopus species indicate that Mel1c(alpha) and Mel1c(beta) receptors may correspond to allelic variants of the same locus. Studies on cells transfected with both receptor cDNAs showed the expression of high-affinity 2-[125I]iodomelatonin binding sites. Agonist stimulation of Mel1c(alpha) receptor was associated with the inhibition of cAMP accumulation stimulated by forskolin (IC50 approximately 10(-10) M) in HeLa, Ltk-, and human embryonic kidney 293 (HEK 293) cells. Mel1c(beta) receptor modulated cAMP in HeLa and HEK 293 cells but not in Ltk- cells. Both receptors inhibited, in a dose-dependent manner, cGMP accumulation in all three cell lines incubated with a phosphodiesterase inhibitor. This effect was localized upstream of soluble guanylyl cyclase and was blocked by pertussis toxin treatment. However, IC50 values (approximately 10(-10) M for Mel1c(beta) and 10(-9) to 10(-7) M for Mel1c(alpha)) and maximal inhibition levels showed that Mel1c(alpha) receptors are much less efficiently coupled to the cGMP pathway. Coupling differences may be explained by the fact that five of the six amino acid substitutions between Mel1c(alpha) and Mel1c(beta) receptors are located within cytoplasmic regions potentially involved in signal transduction. The existence of coupling differences is in agreement with the observation that expression of both receptors is evolutionally conserved in native tissue. In conclusion, two novel, potentially allelic, isoforms of Xenopus Mel1c melatonin receptors display identical ligand-binding characteristics, but different potencies in modulating cAMP and cGMP levels through G(i)/G(o)-dependent pathways. Furthermore, to our knowledge, this study provides the first data on the modulation of intracellular cGMP levels by cloned melatonin receptors.

Microbial biotransformations of a synthetic immunomodulating agent, HR325

The microbial biotransformation of HR325 [2-cyano-3-cyclopropyl-3-hydroxy-N-(4'-trifluoromethyl-3'-methylphenyl)- propenamide], a synthetic immunomodulating agent, has been investigated in order to be compared with animal metabolism and to prepare some metabolites which are difficult to obtain by chemical methods. Several fungal strains are able to completely metabolize this drug. Mortierella isabellina NRRL 1757 only achieves a benzylic hydroxylation on the aromatic methyl group, affording in high yield the corresponding hydroxymethyl derivative. In addition, other strains, such as Cunninghamella elegans ATCC 26269 or Beauveria bassiana ATCC 7159 can cleave both cyclopropyl and cyano groups in a new unknown oxidative biochemical reaction, which can be mimicked by m-chloroperbenzoate oxidation. The resulting cyanohydrin is hydrolyzed and reduced to a primary alcohol. In B. bassiana, the final incubation product is a beta-4-O-methylglucoside derivative of this alcohol, and has been fully characterized by independent synthesis. The different metabolic patterns of HR325 in the three fungal strains are discussed, and a mechanistic hypothesis about the oxidative cleavage of the right part of the molecule is proposed. The production of microbial metabolites is compared to animal metabolism in terms of structure and efficiency.

[Herpesvirus infection: from the primary oral lesion to recurrent herpes]

This paper presents an overview of the clinical conditions associated with a herpetic lesion at the time of the primary infection, as a true primary infection or a first herpetic accident, or during recurrences. The virus responsible, its anatomy and its functioning are detailed. The etiology and transmission of herpetic viral infection, its evolution and complications, as well as diagnostic aids are also discussed. To complete the discussion of this chronic disease which can cause acute annoyances treatment, particularly for children is reviewed, and suggestions are made to prevent it.

Use of monoclonal antibodies for identification of growth-controlling neuropeptides in the mussel Mytilus edulis (Mollusca:Bivalvia)

Monoclonal antibodies were developed against cerebral ganglia (CG) of the mussel Mytilus edulis by the immunization of mice with unpurified homogenates of these organs. The screening protocol of hybridoma was based upon immunohistological observations of cytocentrifugated ganglia cells. A panel of 29 monoclonal antibodies (MABs) specific of CG epitopes was harvested and subsequently used for the immunocytochemical study of CG cells. Several subpopulations of ganglia cells were specifically revealed by MABs. Identification of epitopes involved in growth control was approached via the application of a bioassay allowing the assessment of protein synthesis stimulation. MAB 42 and 46 affected amino acid incorporation induced by CG extract. These results lead to the conclusion that the epitopes recognised by these antibodies are involved in growth control. An immunoenzymatic assay was performed with CG extracts for quantitative analyses of epitopes.

Endothelins stimulate c-fos and nerve growth factor expression in astrocytes and astrocytoma

Endothelin receptors have been identified on astrocytes and astrocytoma, but their physiological significance has remained elusive. It is shown here that endothelins induce c-fos in primary cultures of mouse embryo astrocytes, as well as in two subclones of rat astrocytoma C6 cells, although with different kinetics. In addition, nerve growth factor expression is stimulated, as seen by mRNA accumulation and protein secretion, in primary astrocytes and one of the two C6 subclones, with an apparent correlation with the transience of c-fos induction. The activation of protein kinase C appears as an obligatory step during these processes, because (a) inhibition of protein kinase C by staurosporine blocks the induction by endothelin or phorbol esters of both c-fos and nerve growth factor, and (b) phorbol ester-evoked down-regulation of protein kinase C completely abolishes the c-fos induction by endothelin, but not that by the beta-adrenergic agonist isoproterenol, a known activator of the cyclic AMP-dependent pathway. Our results support the hypothesis that c-fos product might be implicated in nerve growth factor expression by astrocytes, and also suggest that endothelins may participate in vivo in the modulation of the glial neurotrophic activity during brain development or wound healing.