Ischemic preconditioning (IP) of the liver as a safe and protective technique against ischemia/reperfusion injury (IRI)

The aim of the study was to evaluate safety and efficacy of IP in LT, particularly in marginal grafts. From 2007 to 2008, 75 LT donors were randomized to receive IP (IP+) or not (IP-). Considering the graft quality, we divided the main groups in two subgroups (marg+/marg-). IP was performed by 10-min inflow occlusion (Pringle maneuver utilizing a toruniquet). Donor variables considered were gender, age, AST/ALT, ischemia time and steatosis. Recipient variables were gender, age, indication to LT and MELD/CHILD/UNOS score. AST/ALT levels, INR, bilirubin, lactic acid, bile output on postoperative days 1, 3 and 7 were evaluated. Histological analysis was performed evaluating necrosis/steatosis, hepatocyte swelling, PMN infiltration and councilman bodies. Thirty patients received IP+ liver. No differences were seen between groups considering recipient and donor variables. Liver function and AST/ALT levels showed no significant differences between the main two groups. Marginal IP+ showed lower AST levels on day1 compared with untreated marginal livers (936.35 vs. 1268.23; p = 0.026). IP+ livers showed a significant reduction of moderate-severe hepatocyte swelling (33.3% vs. 65.9%; p = 0.043). IP+ patients had a significant reduction of positive early microbiological investigations (36.7% vs. 57.1%; p = 0.042). In our experience IP was safe also in marginal donors, showing a protective role against IRI.

Peroxiredoxin 6 gene: a new physiological and genetic indicator of multiple environmental stress response in Pacific oyster Crassostrea gigas

Peroxiredoxin 6 is a 1-cysteine peroxiredoxin involved in antioxidant processes. We characterised the full-length cDNA and genomic sequence of the gene encoding peroxiredoxin 6 (CgPrx6) in the Pacific oyster, Crassostrea gigas. A phylogenetic analysis of Prx6 sequences showed that the CgPrx6 segregates between vertebrate and invertebrate groups. We analysed the expression of mRNA coding for CgPrx6 using RT-PCR in gills and digestive gland of oysters sampled in different contaminated and reference estuaries of the Atlantic French coast. We also studied CgPrx6 exon 6 polymorphism by PCR-SSCP in the same populations. Our results showed that CgPrx6 gene expression was highly regulated in the estuaries showing differential contamination levels, as expression increased with pollution level. Polymorphism analysis revealed no significant allelic frequency variations between populations. However, heterozygote deficiency seems to occur in the most contaminated estuaries, suggesting a potential selective effect of environmental stress on heterozygote frequency. Finally, the use of CgPrx6 as a possible marker to monitor stress exposure in disturbed ecosystems is discussed.

A French randomized controlled trial of ST-segment analysis in a population with abnormal cardiotocograms during labor

OBJECTIVE

The purpose of this study was to assess whether knowledge of ST-segment analysis was associated with a reduction in operative deliveries for nonreassuring fetal status (NRFS) or with a need for at least 1 scalp pH during labor.

STUDY DESIGN

Seven hundred ninety-nine women at term with abnormal cardiotocography or meconium-stained amniotic fluid (7%) were assigned randomly to the intervention group (cardiotocography + STAN) or the control group (cardiotocography) in 2 university hospitals in Strasbourg, France. Scalp pH testing was optional in both groups. Abnormal neonatal outcome was pH <7.05 or umbilical cord blood artery base deficit of >12 or a 5-min Apgar score of <7 or neonatal intensive care unit admission or convulsions or neonatal death. Study power was 80% for the detection of a prespecified reduction from 50%-40% in operative delivery for NRFS.

RESULTS

The operative delivery (cesarean or instrumental) rate for NRFS did not differ between the 2 groups: 33.6% (134/399) in the cardiotocography + STAN analysis group vs 37% (148/400) in the cardiotocography group (relative risk, 0.91; 95% CI, 0.75-1.10). The rate of operative delivery for dystocia was also similar in both groups. The percentage of women whose fetus had at least 1 scalp pH measurement during labor was substantially lower in the group with ST-segment analysis: 27% compared with 62% (relative risk, 0.44; 95% CI, 0.36-0.52). Neonatal outcomes did not differ significantly between groups.

CONCLUSION

In a population with abnormal cardiotocography in labor, cardiotocography combined with ST-segment analysis was not associated with a reduction in operative deliveries for NRFS. The proportion of infants without scalp pH sampling during labor increased substantially, however.

Microparticles from preeclamptic women induce vascular hyporeactivity in vessels from pregnant mice through an overproduction of NO

Preeclampsia is associated with an increase of circulating levels of microparticles (MPs), but their role in vascular dysfunction during the course of preeclampsia is not understood. Inasmuch as preeclampsia is a gestational disease, we tested the effect of MPs from preeclamptic women (PrMPs) and MPs from normal pregnant women (CMPs) on vessels from pregnant mice. We exposed aortic rings from pregnant mice to circulating levels of PrMPs or CMPs for 24 h and evaluated their response to serotonin (5-HT). PrMPs, but not CMPs, were able to induce hyporeactivity in response to 5-HT in aortas from pregnant mice. The nitric oxide (NO) synthase inhibitor NG-nitro-l-arginine strongly enhanced the response to 5-HT in PrMP-treated vessels but had no significant effect on CMP-treated vessels. The 5-HT-induced contraction in PrMP-treated vessels was completely abolished by the selective cyclooxygenase-2 (COX-2) inhibitor NS-398 but was only reduced in CMP-treated vessels, suggesting an increased participation of COX-2 vasoconstrictor products in the effect of PrMPs. Consistent with this hypothesis, PrMPs enhanced levels of 8-isoprostane and PGE2in vessels, despite reduction of thromboxane B2. These results strengthen the main concept that MPs in preeclampsia could act as vectors to stimulate intracellular cascades in vascular cells, leading to an enhanced NO production to counteract increased COX-2 vasoconstrictor metabolites by taking into account pregnancy.

Fetal electrocardiogram ST-segment analysis and prediction of neonatal acidosis

OBJECTIVE

To determine the diagnostic value of fetal ST-segment analysis (STAN) in predicting neonatal acidosis.

METHODS

The STAN S21 was used to monitor singleton fetuses in labor with abnormal FHR. Physicians later reviewed tracings to identify any ST events dictating intervention. Outcome measures were umbilical artery pH< or =7.15 and pH< or =7.05 at birth. The sensitivity, specificity, PPV, and NPV of a significant ST event to predict both outcomes were calculated.

RESULTS

Analysis included 411 women. Sensitivity of a significant ST event for screening pH< or =7.15 (21.9%) was 38% (41/108), specificity 83% (252/303), PPV 45% (41/92) and NPV 79% (252/319), and for pH< or =7.05, it was (3.4%), 62.5% (10/16), 79% (313/395), 11% (10/92), and 98% (313/319), respectively.

CONCLUSION

In a population with abnormal FHR in labor, STAN sensitivity is moderate (almost 40%) for predicting pH< or =7.15 and better (almost 60%) for more severe acidosis (pH< or =7.05).

Shed membrane particles from preeclamptic women generate vascular wall inflammation and blunt vascular contractility

We investigated the role of microparticles in vascular dysfunction of the multisystemic disorder of preeclampsia in women's omental arteries or mouse arteries. Preeclamptic women displayed increased circulating levels of leukocyte- and platelet-derived microparticles compared with healthy pregnant individuals. Microparticles from preeclamptic, but not healthy, pregnant women induced ex vivo vascular hyporeactivity to serotonin in human omental arteries and mouse aortas. Hyporeactivity was reversed by a nitric-oxide (NO) synthase inhibitor and associated with increased NO production. In the presence of a cyclooxygenase (COX)-2 inhibitor, serotonin-mediated contraction was partially reduced in arteries treated with healthy microparticles but was abolished after treatment with preeclamptic microparticles. This was associated with increased 8-isoprostane production. Preeclamptic microparticles induced up-regulation of inducible nitric-oxide synthase and COX-2 expression, evoked nuclear factor-kappaB activation, and enhanced oxidative and nitrosative stress. Interestingly, the microparticles originating most probably from leukocytes were responsible for the COX-2 vasoconstrictor component of preeclamptic microparticles, whereas those of platelet origin were mainly involved in NO release. Moreover, vascular hyporeactivity was observed in arteries taken from mice treated in vivo with preeclamptic microparticles. This study demonstrates pathophysiological relevance and provides a paradoxical effect of preeclamptic microparticles associated with proinflammatory properties on vessels, leading to enhanced NO and superoxide anion levels and counteraction of increased COX-2 metabolites.

Hepatic involvement in larva migrans of Toxocara canis: report of a case with pathological and radiological findings

Patients with the clinical syndrome of visceral larva migrans as a result of Toxocara species, have typical lesions in the liver consisting of granulomas that contain numerous eosinophils and often Charcot-Leyden crystals. This syndrome is rarely taken into account in patients with cholestatic syndrome, especially when hypereosinophilic reaction is absent. We report the case of a 47-year-old immunocompetent woman who presented with abdominal pain, in whom multiple focal liver lesions were discovered. She had come in contact with dogs. Diagnosis of toxocariasi was done. A good clinical response has been obtained by treating with thiabendazole. We present the findings of various imaging studies of the patient. This report shows that visceral larva migrans may be the cause of a chronic liver disease and should be suspected also in patients without fever and hypereosinophilia with cryptogenic cholestatic and focal liver lesions.

Cutaneous Microcirculation is not altered by a Weak 50 Hz Magnetic Field / Die Mikrozirkulation der Haut in schwachen 50-Hz-Magnetfeldern

Electromagnetic hypersensitivity (EH) is an increasing problem in modern industrial societies. As crawling sensations are frequently mentioned by EH patients alterations in cutaneous microcirculation possibly linked to exposure to magnetic fields might be involved in the development of such sensations and further dysesthesias. In seven healthy volunteers and in three persons convinced to suffer from EH the microcirculation of the right thumb was determined by laser-Doppler-flowmetry (LDF) during exposure to circularly polarized 50 Hz magnetic flux densities of 96 mT. During field exposure the LDF values remained constant. The LDF ratio "field on/field off" was found to be 1.03 +/- 0.03. In contrast, reactive hyperemia and hyperventilation caused significant changes in the LDF values of volunteers as well as of EH patients. Following arterial congestion of the forearm microcirculation of the thumb was clearly increased during reperfusion, and the LDF values were elevated up to 2.02 +/- 0.36. 10 deep breaths caused a significant decrease in the LDF values up to 0.63 +/- 0.18. In conclusion, reactive hyperemia and hyperventilation caused clear alterations of cutaneous microcirculation, whereas, 50 Hz magnetic fields had no influence on cutaneous microcirculation.

Second and third medical termination of pregnancy with misoprostol without mifepristone

BACKGROUND

Advances in prenatal diagnosis make it possible to detect many fetal pathologies for which a termination of pregnancy (TOP) is possible in France. In pregnancies which go beyond 3 months, the use of prostaglandins combined with mifepristone has simplified this procedure. Since mifepristone must be taken 48 h before using prostaglandins, we have used only misoprostol intravaginally.

METHODS

Our report deals with a continuous series of terminated pregnancies in the second and third trimesters. The time period in question is January 1, 1996 through July 31, 2001. When this treatment was used within the first 30 weeks of gestation, four tablets (800 microg) of misoprostol were administered intravaginally. When there were no contractions, two additional tablets (400 microg) of misoprostol were given orally every 3 h, not exceeding 3 times. Beyond 30 weeks of amenorrhoea, because of the risk of uterine rupture, the initial dose was lower: 1/4 tablet (50 microg) of misoprostol intravaginally was increased to 100 microg (1/2 tablet) every 3 h until expulsion.

RESULTS

In the second and third trimesters, 55 pregnancies were terminated medically; only 1 case was not successful. In the other 54 cases, the average time interval between administering misoprostol intravaginally and expulsion was 12.7 +/- 8 h. Side effects included nausea or vomiting for 12 patients (22%) and hyperthermia for 11 patients (20%). Thirty-three patients (60%) had no side effects at all. In 10 cases (18%), the fetus and the placenta were removed in one movement. In 11 cases (20%), the placenta had to be removed by artificial means. In 7 cases (13%), a curettage with a curette foam was done. In the long run perspective, only 1 patient needed a curettage to remove placental residue.

CONCLUSION

Treatment by misoprostol without mifepristone during the second and third trimesters makes it possible to terminate a pregnancy easily and quickly without significant complications.

Utilisation en routine de l’analyse du segment ST de l’électrocardiogramme fœtal pour la surveillance du travail. Une année d’expérience (résultats préliminaires)

OBJECTIVES

Two randomized trials found that monitoring labor by analyzing the fetal electrocardiogram (STAN) appears to offer better sensitivity and specificity in screening for metabolic acidosis than cardiotocography (CTG) does. We report here the results of a descriptive study of 173 cases between 1 June 2001 and 31 May 2002, the objectives of which were twofold: to determine the number of possible false negatives (defined by neonatal metabolic acidosis with a pH less than 7.05 and base deficit (BD) greater than 12 mmol/l, in the absence of a STAN decisions event more than 30 min before birth), and to assess whether STAN indicated the need for operative intervention too late in cases of fetal distress.

PATIENTS AND METHODS

Our study was conducted on an at-risk population with CTG changes. STAN was used with a scalp electrode to monitor labor according to a protocol based upon the FIGO CTG classification and the clinical instructions used in the Swedish trial. Accordingly, we compared two groups: in group 1, a STAN decision event required a rapid conclusion to labor, while in group 2, the absence of any STAN decision event meant that labor continued, despite the changes in the tracing.

RESULTS

We found seven cases with a neonatal pH less than 7.05, but only one may involve a false negative by this method. The mean arterial pH and the number of fetuses born with an arterial pH less than 7.10 did not differ significantly between the two groups, nor were there any significant differences in the mean BD at birth, or the number of children with a BD greater than 12 mmol/l.

CONCLUSION

The results appear to indicate that use of STAN with the usual CTG enables an appropriate response to cases of fetal distress, but it remains difficult to determine the real benefits that can be expected from this method in France. Longer assessment in our population is required before we can assess its actual advantages.

[Mathematical-technical model of passive and active vibrations of the basilar membrane]

On the basis of the physiological measurements made by v. Békésy and Johnstone, we developed a mathematical model to describe passive and active displacement patterns of the basilar membrane. Approximation of the model functions to the measured values is achieved with the aid of the linear least squares method. Using frequency mapping, the distribution of the basilar membrane displacement is presented in three-dimensional graphic form. The resulting application possibilities of this approach, for example, to electronic simulation of inner ear functions and speech processing systems, are discussed.

Sensitivity and positive predictive values of presurgical clinical diagnosis of excised benign and malignant skin tumors: a prospective study of 835 lesions in 778 patients

This article reports on the sensitivity and positive predictive value of clinical diagnosis of benign and malignant skin tumors by expert plastic surgeons in an Israeli clinic. Most published reports have focused on the sensitivity of clinicians' diagnoses, a general measure of the physician's skill that does not predict the rate of accuracy of a physician's diagnoses. Our study of 835 lesions in 778 patients, one of the largest Israeli series, assesses the clinical diagnosis of malignant and benign skin tumors and is one of the few that provide information on the positive predictive value, the measure that is of interest to both physicians and patients. The majority of tumors were benign (56.8 percent), 31.6 percent were malignant, and 11.6 percent were premalignant. Among the 474 benign lesions, 46 percent were nevi. The most common nevi subclass was compound nevi (53 percent), 9 percent of the nevi were dysplastic, and 5 percent were blue nevi. The most common malignant tumor was basal cell carcinoma, accounting for 78 percent of malignant tumors. Although sensitivity for clinical diagnosis of malignancy was 91.3 percent, the positive predictive value for clinical diagnosis of malignancy was 71.3 percent. The sensitivity rate for clinically diagnosing premalignant tumors was 42.3 percent, whereas the positive predictive value for these diagnoses was higher (64.1 percent). The sensitivity rate for diagnosis of all benign lesions was 85.9 percent, and the positive predictive value was 94.2 percent. The sensitivity rate for diagnosis of all nevi was 87.6 percent, and the positive predictive value was 85.7 percent: i.e., only seven of the 218 pathologically proven diagnoses of nevi (3.2 percent) were falsely diagnosed as malignant lesions. Even more interestingly, five of the 223 clinical diagnoses of nevi (2.2 percent) were pathologically proven to be malignant melanomas, and seven were found to be premalignant lesions (3.1 percent). It was concluded that publications which report only on the sensitivity neglect to provide information of interest regarding the positive predictive value. Often, positive predictive value is qualitatively different from the sensitivity, and thus relying only on the sensitivity may lead to incorrect evaluation of a clinical judgment, which may result in erroneous surgical decisions.

SHP1 protein-tyrosine phosphatase inhibits gp91PHOX and p67PHOX expression by inhibiting interaction of PU.1, IRF1, interferon consensus sequence-binding protein, and CREB-binding protein with homologous Cis elements in the CYBB and NCF2 genes

The CYBB and NCF2 genes encode the phagocyte respiratory burst oxidase proteins, gp91PHOX and p67PHOX. Previously, we identified homologous CYBB and NCF2 cis elements that are necessary for lineage-specific transcription during late myeloid differentiation. We determined that these homologous cis elements are activated by PU.1, IRF1, interferon consensus sequence-binding protein (ICSBP), and the CREB-binding protein (CBP). Since expression of PU.1 and ICSBP is lineage-restricted, our investigations identified a mechanism of lineage-specific CYBB and NCF2 transcription. Since PU.1, IRF1, ICSBP, and CBP are expressed in undifferentiated myeloid cells, our investigations did not determine the mechanism of differentiation stage-specific CYBB and NCF2 transcription. In the current investigations, we determine that SHP1 protein-tyrosine phosphatase (SHP1-PTP) inhibits gp91PHOX and p67PHOX expression, in undifferentiated myeloid cell lines, by decreasing interaction of PU.1, IRF1, ICSBP, and CBP with the CYBB and NCF2 genes. We also determine that IRF1 and ICSBP are tyrosine-phosphorylated during interferon gamma differentiation of myeloid cell lines, and we identify IRF1 and ICSBP tyrosine residues that are necessary for CYBB and NCF2 transcription. Therefore, these investigations identify a novel mechanism by which SHP1-PTP antagonizes myeloid differentiation and determine that tyrosine phosphorylation of IRF1 and ICSPB mediates stage-specific transcriptional activation in differentiating myeloid cells.