Author Correction: Yolk sac macrophage progenitors traffic to the embryo during defined stages of development.

This article contains errors in Figs. 5 and 6, for which we apologize. In Fig. 5f, the image 'E12.5 tail' was inadvertently replaced with a duplicate of the image 'E12.5 trunk' from the same panel. In Figure 6d, the image 'E9.5/OH-TAM E8.5, embryo' was inadvertently replaced with a duplicate of the image 'E10.5/ OH-TAM E8.5, embryo' from Fig. 6b. The corrected versions of these figures appear in the Author Correction associated with this Article.

Yolk sac macrophage progenitors traffic to the embryo during defined stages of development.

Tissue macrophages in many adult organs originate from yolk sac (YS) progenitors, which invade the developing embryo and persist by means of local self-renewal. However, the route and characteristics of YS macrophage trafficking during embryogenesis are incompletely understood. Here we show the early migration dynamics of YS-derived macrophage progenitors in vivo using fate mapping and intravital microscopy. From embryonic day 8.5 (E8.5) CX3CR1+ pre-macrophages are present in the mouse YS where they rapidly proliferate and gain access to the bloodstream to migrate towards the embryo. Trafficking of pre-macrophages and their progenitors from the YS to tissues peaks around E10.5, dramatically decreases towards E12.5 and is no longer evident from E14.5 onwards. Thus, YS progenitors use the vascular system during a restricted time window of embryogenesis to invade the growing fetus. These findings close an important gap in our understanding of the development of the innate immune system.

N-Acetylaspartate reduction as a measure of injury severity and mitochondrial dysfunction following diffuse traumatic brain injury.

N-Acetylaspartate (NAA) is considered a neuron-specific metabolite and its reduction a marker of neuronal loss. The objective of this study was to evaluate the time course of NAA changes in varying grades of traumatic brain injury (TBI), in concert with the disturbance of energy metabolites (ATP). Since NAA is synthesized by the mitochondria, it was hypothesized that changes in NAA would follow ATP. The impact acceleration model was used to produce three grades of TBI. Sprague-Dawley rats were divided into the following four groups: sham control (n = 12); moderate TBI (n = 36); severe TBI (n = 36); and severe TBI coupled with hypoxia-hypotension (n = 16). Animals were sacrificed at different time points ranging from 1 min to 120 h postinjury, and the brain was processed for high-performance liquid chromatography (HPLC) analysis of NAA and ATP. After moderate TBI, NAA reduced gradually by 35% at 6 h and 46% at 15 h, accompanied by a 57% and 45% reduction in ATP. A spontaneous recovery of NAA to 86% of baseline at 120 h was paralleled by a restoration in ATP. In severe TBI, NAA fell suddenly and did not recover, showing critical reduction (60%) at 48 h. ATP was reduced by 70% and also did not recover. Maximum NAA and ATP decrease occurred with secondary insult (80% and 90%, respectively, at 48 h). These data show that, at 48 h post diffuse TBI, reduction of NAA is graded according to the severity of insult. NAA recovers if the degree of injury is moderate and not accompanied by secondary insult. The highly similar time course and correlation between NAA and ATP supports the notion that NAA reduction is related to energetic impairment.

Early onset of lipid peroxidation after human traumatic brain injury: a fatal limitation for the free radical scavenger pharmacological therapy?

BACKGROUND: On the basis of the contradiction between data on experimental head trauma showing oxidative stress-mediated cerebral tissue damage and failure of the majority of clinical trials using free radical scavenger drugs, we monitored the time-course changes of malondialdehyde (MDA, an index of cell lipid peroxidation), ascorbate, and dephosphorylated ATP catabolites in cerebrospinal fluid (CSF) of traumatic brain-injured patients. METHODS: CSF samples were obtained from 20 consecutive patients suffering from severe brain injury. All patients were comatose, with a Glasgow Coma Scale on admission of 6 +/- 1. The first CSF sample for each patient was collected within a mean value of 2.95 hours from trauma (SD=1.98), after the insertion of a ventriculostomy catheter for the continuous monitoring of intracranial pressure. During the next 48 hours, CSF was withdrawn from each patient once every 6 hours. All samples were analyzed by an ion-pairing high-performance liquid chromatographic method for the simultaneous determination of MDA, ascorbic acid, hypoxanthine, xanthine, uric acid, inosine, and adenosine. RESULTS: In comparison with values recorded in 10 herniated-lumbar-disk, noncerebral control patients, data showed that all CSF samples of brain-injured patients had high values (0.226 micromol/L; SD=0.196) of MDA (undetectable in samples of control patients) and decreased ascorbate levels (96.25 micromol/L; SD=31.74), already at the time of first withdrawal at the time of hospital admission. MDA was almost constant in the next two withdrawals and tended to decrease thereafter, although 48 hours after hospital admission, a mean level of 0.072 micromol/L CSF (SD=0.026) was still recorded. The ascorbate level was normalized 42 hours after hospital admission. Changes in the CSF values of ATP degradation products (oxypurines and nucleosides) suggested a dramatic alteration of neuronal energy metabolism after traumatic brain injury. CONCLUSIONS: On the whole, these data demonstrate the early onset of oxygen radical-mediated oxidative stress, proposing a valid explanation for the failure of clinical trials based on the administration of oxygen free radical scavenger drugs and suggesting a possible rationale for testing the efficacy of lipid peroxidation "chain breakers" in future clinical trials.

Comparison of NAA measures by MRS and HPLC.

This work investigates the accuracy of an in vivo estimation of absolute N-acetyl aspartate (NAA) concentrations by magnetic resonance spectroscopy (MRS) using cerebral water as an internal reference standard. Single-voxel, proton spectroscopy was carried out in two groups of rats (normal and diffuse head injury), using a PRESS sequence with TR = 3 s, TE = 135 ms. Fully relaxed water spectra and water-suppressed proton spectra were obtained from a 7 x 5 x 5 mm3 volume of tissue. MRI-based brain water content measurements were also performed. Following MRS, HPLC determinations of NAA were carried out. In the normal rats the MRS yielded 10.98 +/- 0.83 mmol/kg w.w. vs 10.76 +/- 0.76 for HPLC with a mean absolute difference of 0.8. In the injured rats the corresponding results were 9.41 +/- 1.78 (MRS) and 8.16 +/- 0.77 (HPLC) with a mean absolute difference of 1.66. The in vivo absolute method accurately documented the temporal NAA changes compared to the NAA/Cr approach.

Ion-pairing high-performance liquid chromatographic method for the detection of N-acetylaspartate and N-acetylglutamate in cerebral tissue extracts.

An ion-pairing high-performance liquid chromatographic method for the determination of N-acetylaspartate and N-acetylglutamate using a C-18 column and a UV detection at 210 nm wavelength, by means of a diode array detector, is presented. A buffer containing 2.8 mM tetrabutylammonium hydroxide, 25 mM KH(2)PO(4), 1.25% methanol, pH 7. 00, is utilized for the isocratic separation of these N-acetylated amino acids, at a flow rate of 1 ml/min and a column temperature of 23 degrees C. The suitability of this chromatographic separation (without additional chromatographic steps prior to HPLC assay) to monitor variations both of N-acetylaspartate and of N-acetylglutamate in perchloric acid brain extracts from rats subjected to the impact acceleration model of diffuse brain injury is also reported. According to the data presented, this HPLC method allows the separation of the two N-acetylated amino acids considered from the many possible interfering compounds, commonly present in extracts of cerebral tissue, which have high extinction coefficients at 210 nm wavelength. Values of N-acetylaspartate and N-acetylglutamate determined by this method showed that cerebral trauma negatively affects both compounds, according to the severity of trauma itself.

Changes of cerebral energy metabolism and lipid peroxidation in rats leading to mitochondrial dysfunction after diffuse brain injury.

The effect of mild closed head trauma, induced by the weight-drop method (450 g from a 1-m height), on lipid peroxidation and energy metabolism of brain tissue was determined at various times after cerebral injury in spontaneously breathing rats (1, 10, 30 minutes and 2, 6, 15, 24, 48, and 120 hours). Animals were continuously monitored for the evaluation of blood pressure, blood gases, heart rate, and intracranial pressure. Analysis of malondialdehyde (MDA) as an index of lipid peroxidation, ascorbic acid, high-energy phosphates, nicotinic coenzymes, oxypurines, and nucleosides was performed by high-performance liquid chromatography (HPLC) on neutralized perchloric acid extract of the whole brain. Data showed that MDA, undetectable in control, sham-operated rats, was already present within 1 minute of trauma (1.77 nmol/g wet weight; SD = 0.29) and reached maximal values by 2 hours (72.26 nmol/g w.w.; SD = 11.26), showing a progressive slow decrease thereafter. In contrast, ATP, GTP, and nicotinic coenzyme (NAD and NADP) concentrations showed significant reduction only by the second hour postinjury. Maximal decrease of the ATP and GTP concentrations were seen at 6 hours postinjury, whereas NAD and NADP concentrations showed maximum decline by 15 hours. Values recorded in mechanically ventilated rats did not differ significantly from those obtained in spontaneously breathing animals. These findings, supported by the absence of blood gas and blood pressure changes in the spontaneously breathing rats, strongly support the premise that biochemical changes (primarily lipid peroxidation) are not caused by secondary ischemic-hypoxic phenomena but rather are triggered by these forces acting on the brain at the time of impact. In addition, these results suggest that depression of energy metabolism might be caused by peroxidation of the mitochondrial membrane with a consequent alteration of the main mitochondrial function-that is, the energy supply.

Trans-sphenoidal treatment of postsurgical cerebrospinal fluid fistula: CT-guided closure.

Cerebrospinal fluid (CSF) leakage after trans-sphenoidal surgery is a troublesome complication with a risk of meningitis and pneumocephalus. We suggest CT-guided intrasphenoidal injection of fibrin sealant through a 12-gauge needle as a simple alternative to surgical management of CSF fistulae. We treated eight patients, operated via the trans-sphenoidal route (five pituitary adenomas, three craniopharyngiomas), for a postoperative CSF leak by CT-guided intrasphenoidal injection of fibrin sealant alone in three cases and fibrin sealant and autologous blood in 5. CT was obtained 10 days after the procedure in all cases. In four patients, the CSF leak was closed successfully at the first attempt. The procedure was repeated on the four remaining patients because only a reduction in leakage was obtained at the first attempt. This procedure preserves olfaction and avoids the risk of frontal lobe damage. It could therefore represent the treatment of choice in many cases of anterior cranial fossa postsurgical CSF leaks.

Computed tomography-guided transsphenoidal closure of postsurgical cerebrospinal fluid fistula: a transmucosal needle technique.

BACKGROUND: Cerebrospinal fluid (CSF) fistula represents a fearful complication of transsphenoidal surgery and, despite careful intraoperative repair and prolonged postoperative lumbar CSF drainage, need for a new surgical intrasphenoidal plasty is not uncommon. METHODS: These cases prompted us to develop a simple, minimally invasive, harmless repeatable technique consisting of a computed tomography (CT)-guided intrasphenoidal injection of fibrin glue through a 12-gauge spinal needle. RESULTS: Five patients presenting with rhinoliquorrhea following a transsphenoidal approach for the excision of pituitary adenomas (three cases) and craniopharyngiomas (two cases) were treated successfully with the presented technique. In two cases the first attempt attained only partial success and therefore the procedure was repeated. In the last two cases, the injection of fibrin glue was preceded by 2 cc of fresh autologous blood, with the aim of enhancing the mechanisms of healing, possibly inducing adhesions and fibrosis. CONCLUSIONS: The proposed method of treatment for CSF leakage following transsphenoidal surgery may represent a valid alternative to the surgical option.

Experimental model of asymmetric brain ischemia and reperfusion in the rat.

BACKGROUND: In this experimental study is illustrated an original model of cerebral asymmetric ischemia and reperfusion in the rat, induced by unilaterally elevating ICP and clamping the corresponding common carotid artery, that allows a direct comparison of the two brain hemispheres, one normal and the other ischemic, of the same animal. METHODS: The experimental procedure consisted in grafting two screws through the skull on the right side of the sagittal suture, one of them being connected to a Queckenstedt manometer for monitoring ICP variations. A nitroprusside solution (1 mg/ml administered through the femoral vein at a flow rate of 0.103 ml/min) was infused to achieve a significant drop of MABP. At this time point, animals were subjected to 5 min of ischemia and 10 min of reperfusion induced by clamping and declamping the right common carotid artery. During the whole period of ischemia and reperfusion ICP and MABP were constantly monitored. In order to provide an outlook on the metabolic alterations of brain tissue occurring during ischemia and reperfusion phenomena, several biochemical parameters of cellular energy metabolism and of oxygen radical-induced membrane damage were determined by a sensitive and reproducible HPLC method on perchloric acid tissue extracts. RESULTS AND CONCLUSIONS: The validity of the present model was supported by the finding of significant intrahemispheric differences in the concentration of several compounds considered as biochemical markers of tissue injury, such as adenosine 5'-triphosphate catabolites and malondialdehyde, this last indicating the damaging action of oxygen free radicals on cell membrane phospholipids.

Effects of increasing times of incomplete cerebral ischemia upon the energy state and lipid peroxidation in the rat.

Different times of incomplete cerebral ischemia (2, 4, 6, 8, 10 and 30 min) were induced by bilateral common carotid artery occlusion in anesthetized rats to evaluate the time course of changes in lipid peroxidation and energy metabolism. Analysis of malondialdehyde (used to assess the levels of lipid peroxidation), ascorbic acid, oxypurines, nucleosides, nicotinic coenzymes and high-energy phosphates, was carried out by high-performance liquid chromatography on neutralized perchloric acid extract of brain tissue. Under the present experimental conditions, malondialdehyde, nicotinic coenzymes and ATP catabolites (oxypurines and nucleosides) were affected by increasing times of ischemia, with respect to control sham-operated rats. In particular, the concentration of malondialdehyde, undetectable in control brains, increased from 1.26 nmol/g wet weight after 2 min of carotid clamping to 13.42 nmol/g wet weight at the end of 30 min of incomplete cerebral ischemia. The presence of oxidative stress was further supported by ascorbic acid depletion, which was particularly significant after 10 and 30 min of incomplete ischemia. Carotid clamping provoked an imbalance between energy production and consumption that was evidenced by a reduction in ATP and GTP concentrations and an increase in ATP degradation products such as AMP, oxypurines and nucleosides. A decrement in the sum of adenine nucleotides and the energy charge potential indicated a progressive malfunctioning of energy-producing metabolic cycles. A possible contribution to such a severe change in energy state might be related to depletion of NAD and NADP, particularly noticeable after the longest incomplete brain ischemia times, that should have provoked a consequent lessening of oxido-reductive reactions. Bilateral carotid clamping causes a significant reduction in brain oxygen and substrate supply that results in inhibition of energy metabolism and triggering of oxygen-radical-induced lipid peroxidation.

Incomplete cerebral ischemia in the rat provokes increase of tissue and plasma malondialdehyde.

Short-term incomplete cerebral ischemia was induced in the rat by bilaterally clamping for 5 min the common carotid arteries; subsequent reperfusion of 10 min was obtained by removing carotid occlusion. At the end of ischemia or reperfusion, animals were sacrificed by decapitation. A control group was represented by sham-operated rats. Peripheral venous blood samples were withdrawn from the femoral vein from rats subjected to cerebral reperfusion 5 min before ischemia, at the end of ischemia, and 10 min after reperfusion. A highly sensitive HPLC method for the direct determination of malondialdehyde, oxypurines, and nucleosides was used on 200 microL of brain tissue and plasma extracts. Incomplete cerebral ischemia induced the appearance of a significant amount of tissue malondialdehyde (undetectable in control animals) and a decrease of ascorbic acid. A further 6.6-fold increase of malondialdehyde and a 18.5% decrease of ascorbic acid occurred after 10 min of reperfusion. Plasma malondialdehyde, which was present in minimal amount before ischemia, significantly increased after 5 min of ischemia, being strikingly augmented after 10 min of reperfusion. A similar trend was observed for oxypurines and nucleosides. From these data, it can be affirmed that tissue concentrations of malondialdehyde and ascorbic acid, and plasma levels of malondialdehyde, oxypurines, and nucleotides, reflect both the oxygen radical-mediated tissue injury and the depression of energy metabolism, thus representing early biochemical markers of short-term incomplete brain ischemia and reperfusion in the rat.

The relevance of malondialdehyde as a biochemical index of lipid peroxidation of postischemic tissues in the rat and human beings.

By using a recently developed ion-pairing high-performance liquid chromatographic method for the direct determination of malondialdehyde (MDA) and several other acid-soluble low-mol-wt compounds (ascorbate, oxypurines, nucleosides, nicotinic coenzymes, high-energy phosphates), the variations of tissue and plasma MDA as a function of ischemia and reperfusion were determined in the rat (isolated Langendorff-perfused hearts and short-term incomplete cerebral ischemia) and in human beings (patients suffering from acute myocardial infarction subjected to fibrinolysis). In the rat, the data obtained indicate that, contrary to what had been previously reported in literature, MDA is not present either in control heart or in control brain. Oxygen deprivation induces the production of a low, but detectable amount of MDA in both heart and brain, whereas reperfusion causes a marked increase of MDA in both tissues. In human beings, plasma MDA was deeply affected only in patients suffering from acute myocardial infarction with successful thrombolysis, thus indicating the occurrence of oxygen radical-mediated tissue injury also in humans. On the whole, these results suggest that MDA is a valid biochemical marker of lipid peroxidation of postischemic tissues, which however needs a reliable analytical technique for its determination.

Time dependence of plasma malondialdehyde, oxypurines, and nucleosides during incomplete cerebral ischemia in the rat.

Incomplete cerebral ischemia (30 min) was induced in the rat by bilaterally clamping the common carotid arteries. Peripheral venous blood samples were withdrawn from the femoral vein four times (once every 5 min) before ischemia (0 time) and 5, 15, and 30 min after ischemia. Plasma extracts were analyzed by a highly sensitive high-performance liquid chromatographic method for the direct determination of malondialdehyde, oxypurines, and nucleosides. During ischemia, a time-dependent increase of plasma oxypurines and nucleosides was observed. Plasma malondialdehyde, which was present in minimal amount at zero time (0.058 mumol/liter plasma; SD 0.015), increased after 5 min of ischemia, resulting in a fivefold increase after 30 min of carotid occlusion (0.298 mumol/liter plasma; SD 0.078). Increased plasma malondialdehyde was also recorded in two other groups of animals subjected to the same experimental model, one receiving 20 mg/kg b.w. of the cyclooxygenase inhibitor acetylsalicylate intravenously immediately before ischemia, the other receiving 650 micrograms/kg b.w. of the hypotensive drug nitroprusside at a flow rate of 103 microliters/min intravenously during ischemia, although in this latter group malondialdehyde was significantly higher. The present data indicate that the determination of malondialdehyde, oxypurines, and nucleosides in peripheral blood, may be used to monitor the metabolic alterations of tissues occurring during ischemic phenomena.(ABSTRACT TRUNCATED AT 250 WORDS)

Antonio Pacchioni (1665-1726): early studies of the dura mater.

The clustering of arachnoid villi along the sagittal sinus forms what is known as "Pacchioni granulations." These structures were first described in 1705 by Antonio Pacchioni, an Italian scientist. Pacchioni was born in Reggio Emilia, Italy, in 1665, and there he received his degree in medicine. Later he moved to Rome where he built a successful career dedicated to medical practice, research, and teaching. He became a friend of some of the leading scientists of his age: Lancisi, Malpighi, and Morgagni, among others. He devoted himself to elucidating the structure and function of dura mater, and in his studies often used the new technique of maceration of anatomical specimens in various fluids. Among Pacchioni's written works, the Dissertatio Epistolaris de Glandulis Conglobatis Durae Meningis Humanae (1705) deserves the greatest consideration as it contains the first description of arachnoid granulations. He compared dura to cardiac muscle and attributed to its "glandulae" (glands) the faculty of secreting lymph for lubrication of the sliding movements between meninges and brain during contractions. Three centuries after Pacchioni's death in Rome in 1726, the fine structure of arachnoid villi has not been fully elucidated; moreover, many questions related to mechanisms underlying cerebrospinal fluid absorption remain unanswered.

MDA, oxypurines, and nucleosides relate to reperfusion in short-term incomplete cerebral ischemia in the rat.

Short-term incomplete cerebral ischemia (5 min) was induced in the rat by the bilateral clamping of the common carotid arteries. Reperfusion was obtained by removing carotid clamping and was carried out for the following 10 min. Animals were sacrificed either at the end of ischemia or reperfusion. Controls were represented by a group of sham-operated rats. Peripheral venous blood samples were withdrawn from the femoral vein from rats subjected to cerebral reperfusion 5 min before ischemia, at the end of ischemia, and 10 min after reperfusion. Neutralized perchloric acid extracts of brain tissue were analyzed by a highly sensitive high-performance liquid chromatography (HPLC) method for the direct determination of malondialdehyde, oxypurines, nucleosides, nicotinic coenzymes, and high-energy phosphates. In addition, plasma concentrations of malondialdehyde, hypoxanthine, xanthine, inosine, uric acid, and adenosine were determined by the same HPLC technique. Incomplete cerebral ischemia induced the appearance of a significant amount (8.05 nmol/g w.w.; SD = 2.82) of cerebral malondialdehyde (which was undetectable in control animals) and a decrease of ascorbic acid. A further 6.6-fold increase of malondialdehyde (53.30 nmol/g w.w.; SD = 17.77) and a 18.5% decrease of ascorbic acid occurred after 10 min of reperfusion. Plasma malondialdehyde, which was present in minimal amount before ischemia (0.050 mumol/L; SD = 0.015), significantly increased after 5 min of ischemia (0.277 mumol/L; SD = 0.056) and was strikingly augmented after 10 min of reperfusion (0.682 mumol/L; SD = 0.094). A similar trend was observed for xanthine, uric acid, inosine, and adenosine, while hypoxanthine reached its maximal concentration after 5 min of incomplete ischemia, being significantly decreased after reperfusion. From the data obtained, it can be concluded that tissue concentrations of malondialdehyde and ascorbic acid, and plasma levels of malondialdehyde, oxypurines, and nucleosides, reflect both the oxygen radical-mediated tissue injury and the depression of energy metabolism, thus representing early biochemical markers of short-term incomplete brain ischemia and reperfusion in the rat. In particular, these results suggest the possibility of using the variation of malondialdehyde, oxypurines, and nucleosides in peripheral blood as a potential biochemical indicator of reperfusion damage occurring to postischemic tissues.

[Antonio Pacchioni (1665-1726): pioneer studies on the dura mater]. / Antonio Pacchioni (1665-1726): studi pionieristici sulla dura madre.

Clustering of arachnoid villi along the sagittal sinus gives rise to the so-called "Pacchionian Granulations". These structures were originally described in 1705 by Antonio Pacchioni, an Italian scientist. Born in Reggio Emilia in 1665, he graduated in Medicine in his hometown and later moved to Rome were he built up a successful career by dedicating to medical practice as well as to research and teaching. He became friend and often collaborated with some of the leading scientists of his age: Lancisi, Malpighi and Morgagni among the others. Moreover he carefully followed research developments in Europe as testified by frequent quoting of foreign authors in his works. He devoted himself to the elucidation of structure and function of Dura Mater, often by using new techniques of maceration of anatomic specimens in various fluids. Among Pacchioni's works, the "Dissertatio epistolaris de glandulis conglobatis Durae Meningis humanae" (1705) is particularly well known and contains the first description of arachnoidal granulations. He compared Dura to cardiac muscle and attributed to its "glandulae" (glands) the faculty of secreting lymph for lubrification of the sliding movements between meninges and brain during contractions. He died in Rome in 1726. Three centuries after Pacchioni's death fine structure of arachnoid villi hasn't been fully elucidated; moreover many questions on mechanisms underlying CSF absorption remain unanswered.

Supracerebellar arachnoid cyst and reversible tonsillar herniation: magnetic resonance imaging and pathophysiological considerations.

A large supracerebellar arachnoid cyst was associated with herniation of the cerebellar tonsils and deformity of the cervicomedullary junction in an adult. Magnetic resonance imaging showed partial restoration of normal anatomy following surgery and clinical improvement, which helped in the formulation of a etiopathogenetic hypotheses.

Potential risk factors for brain tumors in children. An analysis of 200 cases.

Two hundred cases of verified brain tumors occurring in patients under 15 years of age were studied in relation to possible etiologic, genetic, and environmental risk factors. They were compared with 100 age-matched patients harboring solid neoplasms outside the nervous system, as well as with 100 normal children. In our study, first-degree relatives of a brain tumor child did not show a higher incidence of either tumors or of epilepsy and strokes as compared with controls. First-born children (46%) with higher birth weights showed a greater tendency to present brain tumors. Dystocia (18.5%), previous miscarriages (18%), and dietary restrictions during pregnancy (3%) were also noted in this study and compared with data in the literature. No evidence of a role of maternal chickenpox and toxoplasmosis could be found. The pharmacological risk also seemed to be minimal. The mother's hormonal profile is deduced from the age at menarche and delivery, as well as from a tendency to miscarriages and complicated pregnancies. With regard to the immunologic aspect, it is worth noting that 15% of the mothers complained of allergies. Live polio vaccine and zoonosis might suggest a possible role of virus-related factors in the oncogenesis of brain tumors in children. Radiation-related risk is possibly present in less than 5% of cases. Parental occupation is not relevant in this series.