[Toxoplasmosis in pregnancy: Practical Management]. / Toxoplasmose pendant la grossesse : proposition actuelle de prise en charge pratique.

The burden of congenital toxoplasmosis has become small in France today, in particular as a result of timely therapy for pregnant women, fetuses and newborns. Thus, the French screening and prevention program has been evaluated and recently confirmed despite a decline over time in the incidence of toxoplasmosis. Serological diagnosis of maternal seroconversion is usually simple but can be difficult when the first trimester test shows the presence of IgM, requiring referral to an expert laboratory. Woman with confirmed seroconversion should be referred quickly to an expert center, which will decide with her on treatment and antenatal diagnosis. Although the level of proof is moderate, there is a body of evidence in favor of active prophylactic prenatal treatment started as early as possible (ideally within 3 weeks of seroconversion) to reduce the risk of maternal-fetal transmission, as well as symptoms in children. The recommended therapies to prevent maternal-fetal transmission are: (1) spiramycin in case of maternal infection before 14 gestational weeks; (2) pyrimethamine and sulfadiazine (P-S) with folinic acid in case of maternal infection at 14 WG or more. Amniocentesis is recommended to guide prenatal and neonatal care. If fetal infection is diagnosed by PCR on amniotic fluid, therapy with P-S should be initiated as early as possible or continued in order reduce the risk of damage to the brain or eyes. Further research is required to validate new approaches to preventing congenital toxoplasmosis.

[Effects of deformational plagiocephaly during the first 12 months on the psychomotor development of prematurely born infants]. / Effets de la plagiocéphalie posturale au cours des 12 premiers mois sur le développement psychomoteur à 4 ans des enfants nés très prématurément.

AIMS: The link between deformational plagiocephaly and psychomotor development is a recurrent question in medical publications. Main publications concentrate on term infants, but there is a lack of data on the impact of deformational plagiocephaly on the long-term neurodevelopment of premature infants. We attempted to establish a possible relation between deformational plagiocephaly during the 1st year of life and the psychomotor score at 4 years in prematurely born infants. Other risk factors potentially impacting the psychomotor score were also studied. MATERIAL AND METHODS: A retrospective study of the files of the children followed by the "Naître et Devenir Région PACA Ouest Corse Sud" healthcare network and included in the database allowed us to select a cohort of 594 infants born prematurely at under 33 weeks of gestational age. These children were developmentally evaluated during the 1st year of life and at 4 years or age using the "EVAL Mater" test. The "Naître et Devenir" network is following up infants born prematurely at under 33 weeks of gestation in the West Provence Alpes Côte d'Azur and South Corsica region, from discharge to 7 years. A group of 170 specially trained pediatricians follow these infants developmentally at term, 3, 6, 9, 12, 18, and 24 months of corrected age and 3, 4 5, 6, and 7 years. Data are collected in a specially designed database. RESULTS: There was no significant link between deformational plagiocephaly during the 1st year of life and a pathological psychomotor score at age 4, but some risk factors were demonstrated: male gender, birth at under 28 weeks of gestational age, weight at birth under 1000g, having a Latal and Ferriero neuromotor score equal to or greater than 2 at 3 months of corrected age, and to a lesser extent having a prescription for physiotherapy during the 1st year. CONCLUSION: The research on deformational plagiocephaly in the full-term infant suggests a relation between deformational plagiocephaly and developmental delay predominantly on the motor side, with an increased rate of special needs services at school age. The question is raised of whether deformational plagiocephaly is the cause of the delay or an early sign of cerebral anomaly with an early motor delay in full-term infants. The results suggest that deformational plagiocephaly in the prematurely born infant may not be related to neurodevelopmental delay but simply to the extended time spent in the supine position because of the early birth associated with physiological hypotonia and axial extension. Other risk factors such as male gender, birth before 28 weeks of gestation, weight less than 1000g, a Latal and Ferriero neuromotor score greater than 2 at 3 months of corrected age, and having a prescription for physiotherapy during the 1st year of life are strongly related to delayed psychomotor development at age 4.

Spatial and temporal MRI profile of ischemic tissue after the acute stages of a permanent mouse model of stroke.

OBJECT: To characterize the progression of injured tissue resulting from a permanent focal cerebral ischemia after the acute phase, Magnetic Resonance Imaging (MRI) monitoring was performed on adult male C57BL/6J mice in the subacute stages, and correlated to histological analyses. MATERIAL AND METHODS: Lesions were induced by electrocoagulation of the middle cerebral artery. Serial MRI measurements and weighted-images (T2, T1, T2* and Diffusion Tensor Imaging) were performed on a 9.4T scanner. Histological data (Cresyl-Violet staining and laminin-, Iba1- and GFAP-immunostainings) were obtained 1 and 2 weeks after the stroke. RESULTS: Two days after stroke, tissues assumed to correspond to the infarct core, were detected as a hyperintensity signal area in T2-weighted images. One week later, low-intensity signal areas appeared. Longitudinal MRI study showed that these areas remained present over the following week, and was mainly linked to a drop of the T2 relaxation time value in the corresponding tissues. Correlation with histological data and immuno-histochemistry showed that these areas corresponded to microglial cells. CONCLUSION: The present data provide, for the first time detailed MRI parameters of microglial cells dynamics, allowing its non-invasive monitoring during the chronic stages of a stroke. This could be particularly interesting in regards to emerging anti-inflammatory stroke therapies.

Do early MRI signals predict lesion size in a neonatal stroke rat model?

SUMMARY: In this study, we compared lesion size by using VADC and VT2 at 0, 2, 5, 24, and 48 hours and histologic lesions at 48 hours in a P7 rat stroke model. The best correlation between VHISTO and VADC was at H0, and between VHISTO and VT2, at H2-H5. Early MR imaging signals allowed excluding "no-lesion" and "no-reflow" animals to help standardize this neonatal stroke model and predict lesion size.

Long-term ocular outcome in congenital toxoplasmosis: a prospective cohort of treated children.

OBJECTIVES: Congenital toxoplasmosis remains a public health problem throughout the world. Long-term longitudinal studies are still needed to argument controversial screening and treatment strategies and to enable to accurately counsel parents. METHODS: We conducted a prospective cohort study over 16 years in Marseilles, France. Seronegative pregnant women underwent monthly serological testing. Children were treated antenatally with rovamycine as soon as maternal infection was detected and with pyrimethamine and sulfadoxine in case of positive Toxoplasma PCR on amniotic fluid. Postnatal treatment with pyrimethamine and sulfadoxine was systematically prescribed for one year and possibly continued at the physician discretion. RESULTS: 127 children were included. 24 children (18.9%) presented ocular lesions causing visual impairment in eight cases. Eleven children (8.7%) presented with ocular lesions at birth, mostly macular. Sixteen children (12.6%) developed ocular lesions during follow-up, mostly peripheral. The first ocular lesion could occur as late as 12 years after birth. No significant risk factor of chorioretinitis was identified including gestational age at infection, type of antenatal treatment and shorter postnatal treatment. CONCLUSIONS: These results confirm the overall good prognosis of congenital toxoplasmosis in Europe but highlight though a low risk of late ocular manifestation. Chorioretinitis affected 18.9% of children suffering from congenital toxoplasmosis despite antenatal and neonatal screening associated with early treatment. Long-standing follow-up is needed because first lesion can occur as late as 12 years after birth. Late lesions were less often macular but nevertheless caused sometimes visual impairment.

[Fetomaternal anti-RH3, -4 (anti-E and anti-c) rhesus isoimmunization: a case report]. / Allo-immunisation fœto-maternelle rhésus anti-RH3, 4 (anti-E et anti-c) : à propos d'un cas.

Hemolytic disease of the newborn caused by maternal isoimmunization has been decreasing over the past 10 years because of prophylactic treatment with anti-RH1 (anti-D) immunoglobulin. Nevertheless, there is an increase in the incidence of both relative and absolute numbers of non-RH1 red-cell maternofetal isoimmunizations, essentially anti-RH4 (anti-c), anti-RH3 (anti-E), and anti-Kell. In 8 to 14% of cases, multispecificity antibodies are present, the most common combination being the association of anti-RH3 and -4. Despite absence of specific prophylactic therapy, anti-RH4 isoimmunization could be as severe as anti-RH1 ; as for anti-RH3, it is usually associated with mild to moderate clinical manifestations. Nevertheless, there are few publications on anti-RH3, -4 maternofetal isoimmunization with a bias toward the most severe cases being reported. We report here a case of nonsevere maternofetal anti-RH3, -4 isoimmunization complicated with severe hyperbilirubinemia and delayed profound anemia. Hyperbilirubinemia was controlled using intensive phototherapy. Although anemia was absent at birth, it appeared progressively with a nadir at 7.8 g/dL at 1-month postnatal age. Blood counts were monitored for 3 months but the patient did not require red blood cell transfusion. This report underlines the need for a prolonged and rigorous pediatric follow-up of children born in the context of maternofetal isoimmunization after the acute neonatal period. Furthermore, it stresses the necessity of DAT testing in all pregnant women, even those who are RH1-positive.

In vivo 2D magnetic resonance spectroscopy of small animals.

Localized in vivo NMR spectroscopy, chemical shift imaging or multi-voxel spectroscopy are potentially useful tools in small animals that are complementary to MRI, adding biochemical information to the mainly anatomical data provided by imaging of water protons. However the contribution of such methods remains hampered by the low spectral resolution of the in vivo 1D spectra. Two-dimensional methods widely developed for in vitro studies have been proposed as suitable approaches to overcome these limitations in resolution. The different homonuclear and heteronuclear sequences adapted to in vivo studies are reviewed. Their specific contributions to the spectral resolution of spectroscopic data and their limitations for in vivo investigations are discussed. The applications to experimental models of pathological processes or pharmacological treatment in mainly brain and muscle are presented. According to their combined sensitivity, acquisition duration and spatial resolution, the heteronuclear 2D experiments, which are mainly used for 1H detected-13C spectroscopy after administration of 13C-labeled compounds, appear to be less efficient than 1H detected-13C 1D methods at high field. However, the applications of 2D proton homonuclear methods show that they remain the best tools for in vivo studies when an improved resolution is required.

Dynamic in vivo measurement of erythrocyte velocity and flow in capillaries and of microvessel diameter in the rat brain by confocal laser microscopy.

A new method for studying brain microcirculation is described. Both fluorescently labeled erythrocytes and plasma were visualized on-line through a closed cranial window in anesthetized rats, using laser-scanning two-dimension confocal microscopy. Video images of capillaries, arterioles, and venules were digitized off-line to measure microvessel diameter and labeled erythrocyte flow and velocity in parenchymal capillaries up to 200 microm beneath the brain surface. The method was used to analyze the rapid adaptation of microcirculation to a brief decrease in perfusion pressure. Twenty-second periods of forebrain ischemia were induced using the tour-vessel occlusion model in eight rats. EEG, arterial blood pressure, and body temperature were continuously controlled. In all conditions, labeled erythrocyte flow and velocity were both very heterogeneous in capillaries. During ischemia, capillary perfusion was close to 0, but a low blood flow persisted in arterioles and venules, while EEG was flattening. The arteriole and venule diameter did not significantly change. At the unclamping of carotid arteries, there was an instantaneous increase (by about 150%) of arteriole diameter. Capillary erythrocyte flow and velocity increased within 5 seconds, up to, respectively, 346 +/- 229% and 233 +/- 156% of their basal value. No capillary recruitment of erythrocytes was detected. All variables returned to their basal levels within less than 100 seconds after declamping. The data are discussed in terms of a possible involvement of shear stress in the reperfusion period.

Quantitative, scalable discrete-event simulation of metabolic pathways.

DMSS (Discrete Metabolic Simulation System) is a framework for modelling and simulating metabolic pathways. Quantitative simulation of metabolic pathways is achieved using discrete-event techniques. The approach differs from most quantitative simulators of metabolism which employ either time-differentiated functions or mathematical modelling techniques. Instead, models are constructed from biochemical data and biological knowledge, with accessibility and relevance to biologists serving as key features of the system.

Antenatal rupture of a diverticular rectal duplication with neonatal perineal fistulization.

A cystic pelvic malformation was found in a fetus on antenatal sonography (US) at 26 weeks of gestational age that was no longer present 3 weeks later on control US. The male child presented at birth with a right-sided perineal mass that fistulized with meconial drainage. A radiopaque enema showed a low posterior rectal fistula filling a poorly delineated pouch. Surgery performed through a posterior sagittal approach allowed identification and closure of the fistula and pouch drainage. The diagnosis of a diverticular rectal duplication was considered, although no intestinal lining was observed macroscopically or histologically. The child's anorectal function was normal after a 20-month follow-up. Labeling of the malformation and embryological hypotheses are discussed since the case does not fulfill all the criteria of an intestinal duplication. Surgical techniques are discussed, with an emphasis on the sagittal posterior approach.

Spreading of vasogenic edema and cytotoxic edema assessed by quantitative diffusion and T2 magnetic resonance imaging.

BACKGROUND AND PURPOSE: The apparent diffusion coefficient (ADC) of water should be sensitive to the cytotoxic edema triggered by energy failure during ischemia. Elevated values of T2. the nuclear MR transverse relaxation time of water, seen on T2 nuclear MR images detect vasogenic edema and infarcted areas. The temporal and spatial changes in ADC and T2 abnormalities after occlusion of the middle cerebral artery (MCAO) were therefore estimated by these two quantitative techniques. METHODS: Permanent MCAO was performed on rats. Quantitative ADC and T2 maps of brain water were obtained, from which the ischemic volumes were calculated at various times up to 48 hours after MCAO. RESULTS: The areas of decreased ADC represented 36 +/- 7% of the final infarct volume (24 hours) at 0.5 hours and 64 +/- 4% at 5 hours after MCAO, suggesting that there is recruitment of peripheral areas with disturbed energy metabolism and cytotoxic edema. The ADC and T2 contours closely matched at 3.5, 24, and 48 hours after MCAO. CONCLUSIONS: T2 imaging can assess ischemic insults as well as ADC imaging, but only 3.5 hours after the onset of ischemia. Assessment of edematous swelling (approximately 24.5% of total infarcted volume) demonstrates that ADC and therefore T2 imaging detect all the tissue that will become infarcted approximately 7 hours after occlusion. The spread of ADC and T2 abnormalities would therefore stop at approximately 7 hours, and any further increase in volume observed on the images would be mainly due to edematous swelling.

The effects of a butanediol treatment on acute focal cerebral ischemia assessed by quantitative diffusion and T2 MR imaging.

Increased water T2 values indicates the presence of vasogenic edema. Decreased apparent diffusion coefficient (ADC) maps reveal ischemic areas displaying cytotoxic edema. ADC and T2 abnormalities spread through the middle cerebral artery (MCA) territory up to 24 h after middle cerebral artery occlusion (MCAO). Also, it was found that ADC and T2 contours closely match at 3.5 and 24 h. Since butanediol reduces vasogenic edema and improves energy status in various models of ischemia, we used these two techniques to investigate putative improvements in cytotoxic and vasogenic edema after permanent MCAO performed on rats. Rats were given no treatment (n = 8), or a treatment with 25 mmol/kg intraperitoneal (i.p.) butanediol (n = 5), 30 min before and 2.5 h after MCAO. Quantitative ADC and T2 maps of brain water were obtained, from which the volumes presenting abnormalities were calculated at various time points up to 24 h. Effects of butanediol on the ADC and T2 values in these areas were determined. Butanediol reduced neither the ADC volume nor the initial ADC decline. However, it reduced T2 volumes by 32% at 3.5 h and 15% at 24 h (p < 0.05), and reduced T2 increase in the striatum at 3.5 h post-MCAO. Therefore, our results show for the first time that a pharmacological agent such as butanediol can delay the development of vasogenic edema but does not limit the development of vasogenic edema but does not limit the development of cytotoxic edema. ADC imaging detects areas of severe metabolic disturbance but not moderately ischemic peripheral areas where butanediol is presumed to be more efficacious.

Delayed progression of cytotoxic oedema in focal cerebral ischemia after treatment with a torasemide derivative: a diffusion-weighted magnetic resonance imaging study.

Diffusion-weighted magnetic resonance imaging (MRI) was used to assess the effect of an astrocytic Na+2Cl-K+ cotransporter inhibitor, a novel torasemide derivative, on the time course and spatial evolution of a focal cerebral ischemia in the rat. The drug (1 mg/ kg, i.p.) was injected 30 min before middle cerebral artery occlusion and diffusion-weighted images were acquired at various times thereafter. The results showed that the drug reduced the size of the hyperintensity during the first hours, but did not affect the time constant of growth or the final size. The temporary reduction of the cytotoxic oedema induced by the torasemide derivative, demonstrates an antioedematous activity.

A one-dimensional (proton and phosphorus) and two-dimensional (proton) in vivo NMR spectroscopic study of reversible global cerebral ischemia.

The suitability of two-dimensional (2D) proton spectroscopy for monitoring, in vivo, the changes in levels of brain metabolites induced by cerebral ischemia was investigated in an experimental model of 30-min reversible ischemia induced by four-vessel occlusion in the rat. The resulting data were compared with those obtained by one-dimensional (1D) proton and phosphorus spectroscopy. Phosphorus spectra obtained during ischemia showed significant drops in levels of phosphocreatine (-73%), beta-ATP (-60%), and intracellular pH (to 6.30) and an increase in inorganic phosphate level (905%). 1D and 2D proton spectra showed decreases in the N-acetylaspartate/creatine-phosphocreatine ratio that were not significantly different [-21% (1D) and -32% (2D)]. Similarly, the increases in lactate/creatine-phosphocreatine ratio were not significantly different [2,546% (1D) and 3,020% (2D)]. 2D spectroscopy also indicated a decrease in aspartate (-66%) and an increase in the inositol-choline derivative (+124%) pools during ischemia and an increase in alanine pool (+516%) during reperfusion. The glutamate-glutamine pool and taurine content did not change significantly during ischemia but decreased during reperfusion. The glucose level transiently decreased (-67%) during ischemia and increased immediately after (+261%). The levels of all the metabolites investigated returned to control values within 175 min after ischemia. 2D spectroscopy seems to be a reliable method of monitoring the changes in levels of cerebral compounds known to be involved in ischemia.

Cerebral metabolic changes induced by MK-801: a 1D (phosphorus and proton) and 2D (proton) in vivo NMR spectroscopy study.

The dynamic effects of the non-competitive NMDA receptor antagonist, MK-801 on brain metabolism were investigated over 105 minutes in unanesthetized rats by proton and phosphorus NMR spectroscopy. MK-801 (0.5 and 5 mg/kg, i.p) induced no changes in intracellular pH, and in phosphocreatine, ATP, and inorganic phosphate levels, indicating that the drug preserved energy and intracellular pH homeostasis. There were transient increases in lactate after both doses of MK-801, suggesting early activation of glycolysis, which was not immediately matched by enhanced oxidative metabolism or by enhanced blood flow. Thereafter, lactate control level was not restored after 0.5 mg/kg whereas it was restored after 5 mg/kg in spite of a sustained metabolic activation. The low dose of MK-801 also caused a continuous decrease in cerebral aspartate level (-38%) which is thought to match the enhanced energy demand, whereas the high dose caused shorter and smaller changes. The intracerebral glucose level rose after MK-801 injection, indicating that brain tissue had an adequate or even excessive supply of glucose. Glucose time course seemed to closely match the changes in blood flow elicited by MK-801. This is the first study giving the metabolic pattern of a pharmacological activation. We demonstrate an excess of glycolysis over oxidative metabolism in the early time similar to that following physiological and pathophysiological states such as photic stimulation and seizures. The difference between the effects of the two doses of MK-801 suggests that the adjustment of cerebral metabolism to MK-801 activation is faster and greater with the high dose than with the low dose.

Effects of kainate-induced seizures on cerebral metabolism: a combined 1H and 31P NMR study in rat.

The cerebral metabolic changes elicited by kainate-induced seizures in the rat were investigated by in vivo combined NMR spectroscopy of 31P and 1H. Systemic injection of kainate induced no significant changes in cerebral ATP or PCr levels during up to 90 min of continuous, generalised seizures, and the cerebral 31P spectra showed only a transient mild cerebral acidosis 30 min after kainate administration. In parallel with the changes in intracellular cerebral pH, the 1H spectra showed a significant increase in lactate, which remained elevated throughout the seizures. These findings indicate that oxidative metabolism does not completely match the increased glycolysis during seizures though the energy homeostasis is maintained. This suggests that oxidative metabolism has a limited capacity to satisfy the brain's energy needs during the kainate-induced seizures, but that the different pathways of energy production in the brain cells can overcome this limitation. Thus the brain damage associated with this experimental model of epilepsy is not due to extended major failure of the energy supply.

Metabolic effects of kynurenate during reversible forebrain ischemia studied by in vivo 31P-nuclear magnetic resonance spectroscopy.

The metabolic effects of kynurenate, an endogenous excitatory amino acid antagonist, were studied by in vivo 31P-NMR spectroscopy before, during and after reversible forebrain ischemia in the rat. Kynurenate had no effect on cerebral metabolism before ischemia. During a 30-min ischemia, kynurenate protected against the decrease in phosphocreatine (up to -55 +/- 3% vs -73 +/- 3% in the reference group) and the increase in inorganic phosphate (up to +479 +/- 39% vs +805 +/- 66%), whereas there was no statistical difference in the decrease in intracellular pH (up to 6.37 +/- 0.05 vs 6.30 +/- 0.03) and ATP (up to -60 +/- 3% vs -60 +/- 7%). The recovery of PCr, Pi, and pHi to control levels during recirculation was faster in the treated group than in the reference group, whereas the time course of ATP recovery was similar in both groups. We conclude that kynurenate protects against neuronal loss, as previously reported, by mechanisms other than metabolic protection.

Metabolic effects of R-phenylisopropyladenosine during reversible forebrain ischemia studied by in vivo 31P nuclear magnetic resonance spectroscopy.

The metabolic effects of R-phenylisopropyladenosine (R-PIA), an agonist of adenosine A1 receptors, were studied by in vivo 31P NMR spectroscopy before, during, and after 30 min of reversible forebrain ischemia in the rat. R-PIA had no effect on cerebral metabolism before ischemia. During a 30-min ischemia, R-PIA reduced the decrease in phosphocreatine (43 +/- 11% of the control level at the end of ischemia vs. 27 +/- 9% in the reference group) and ATP (58 +/- 12% vs. 40 +/- 23%) and the increase in inorganic phosphate (672 +/- 210% vs. 905 +/- 229%). The intracellular acidosis elicited by ischemia was also less in the treated group (pH of 6.40 +/- 0.10 vs. 6.30 +/- 0.10). Recirculation was associated with a faster recovery of PCr, ATP, Pi, and pHi to control levels in the treated group than in the reference group. It is concluded that adenosine protects against ischemic injury by mechanisms that include metabolic protection.

[Value of in vivo NMR spectroscopy in the study of cerebral metabolism under inhalation anesthesia]. / Intérêt de la spectroscopie RMN in vivo pour l'exploration du métabolisme cérébral sous anesthésie volatile.

NMR in vivo spectroscopy is one of the few methods available for non-invasive investigations of cerebral metabolism in animals and humans. 31P and 1H spectroscopy are particularly suitable for monitoring the cerebral energy metabolism by determining the cerebral levels of ATP, ADP, phosphocreatine (PCr), inorganic phosphate (Pi), lactate and intracellular pH (pHi). These techniques also seem to be suitable for studying the effects of anesthetics by directly comparing the anesthetized and unanesthetized states in the same subject. The effects of halothane and isoflurane on the changes elicited in the cerebral energy metabolism by experimental hypercapnia were investigated by in vivo NMR spectroscopy. Halothane was found to aggravate the decrease in PCr attributed to the shift in creatine kinase equilibrium induced by the cerebral acidosis associated to hypercapnia, while the level of cerebral ADP was decreased to a lesser extent than in unanesthetized animals. In contrast isoflurane did not modify the changes in cerebral energy metabolism elicited by hypercapnia except that the decrease in PCr was significantly slowed, suggesting a lower creatine kinase activity. These data indicate that isoflurane and halothane act by two different mechanisms to produce a decrease in oxygen consumption. Halothane could interfere with oxidative metabolism by disturbing ATP metabolism, while isoflurane could decrease oxygen consumption by a general sedative action, slowing both cerebral functional activity and cerebral energy homeostasis.