Ab Initio Phase Diagram of Gold in Extreme Conditions

A phase diagram of gold is proposed in the [0; 1000] GPa and [0; 10 000] K ranges of pressure and temperature, respectively, topologically modified with respect to previous predictions. Using finite-temperature ab initio simulations and nonequilibirum thermodynamic integration, both accelerated by machine learning, we evaluate the Gibbs free energies of three solid phases previously proposed. At room temperature, the face-centered cubic (fcc) phase is stable up to ∼500  GPa whereas the body-centered cubic (bcc) phase only appears above 1 TPa. At higher temperature, we do not highlight any fcc-bcc transition line between 200 and 400 GPa, in agreement with ramp-compressed experiments. The present results only disclose a bcc domain around 140-235 GPa and 6000-8000 K, consistent with the triple point recently found in shock experiments. We demonstrate that this re-stabilization of the bcc phase at high temperature is due to anharmonic effects.

P14.03.B Glutamate excitotoxicity in brain metastases from lung, breast, and melanoma treated with stereotactic radiosurgery

Background

Brain metastases (BM) are the most frequent neoplasm in the central nervous system (CNS) and primary tumors frequently involved are melanoma, lung cancer and breast cancer. CNS localisation is associated with poor prognosis, and stereotactic radiosurgery (SRS) represents a treatment option for patients with a good performance status. Glutamate (Glu) is a neurotransmitter which plays a facilitating role in carcinogenesis and progression of malignant tumors, as well as in excitotoxicity. Glu efflux from the brain is regulated by scavengers glutamic oxaloacetic transaminase (GOT), glutamate-pyruvate transaminase (GPT) and lactate dehydrogenase (LDH), with aspartate and lactate as catabolites. Glu efflux from the brain seems to be impaired in advanced-stage cancers, resulting in increased blood Glu levels where scavengers exert a protective role. Our hypothesis is that serum Glu and scavengers’ levels are related to neuroinvasion and treatment response in patients with BM and may represent potential biomarkers for BM course and prognosis.

Material and Methods

Serum Glu scavengers (GOT1, GPT and LDH), serum Glu, aspartate and lactate levels are collected in included patients treated and grouped in A) BM group of patients affected by BM from lung or breast cancer or melanoma, treated with SRS; B) Control-1 group of patients affected by lung cancer, breast cancer or melanoma but without BM and C) Control-2 group of patients with benign intracranial lesions (meningiomas, acoustic schwannomas) treated with SRS.In A) and C) serum metabolites and scavengers will be analyzed before and after SRS treatment (at 3, 6, 9 months) while in B) analyzed once. Blood levels in A) and C) help in identifying differences related to malignancy, the role of SRS and the association with disease control, while blood levels in A) and B) help in detecting differences related to BMs. Exclusion criteria are surgical or previous radiosurgical treatment for BM. This study has received Institutional Ethical Committee approval on 3rd August 2020 (Project NCH04-2020, Clinicaltrials.gov identifier: NCT04785521).

Preliminary results

Comparison between BM group (n = 32) and Control-1 (n=18) revealed a significant difference in LDH (271.93 vs 217.56 U/L; p 0.041) and lactate (1.86 vs 1.34 mmol/L, p = 0.022) and a trend towards significance in glutamate (103.43 vs 73.74 µmol/L, p = 0.07). Comparison between BM group (n=32) and Control-2 (n = 37) revealed a difference in LDH (271.93 vs 210.89 U/L; p < 0.001), lactate (1.86 vs 1.24 mmol/L; p < 0.001), aspartate (16.36 vs 10.22 µmol/L, p 0.006) and glutamate levels (123 vs 103 µmol/L, p = 0.052).

Conclusion

The present study is the first one addressing serum glutamate and scavenger levels in patients with BM. If the hypothesis will be confirmed, new targets in glutamate signalling pathway could be identified to define new therapeutic strategies in this challenging disease.

P15.02.B Spatial habitat analysis in high-grade gliomas combining perfusion, diffusion, and hypoxia features derived from multiparametric MRI and 18F-FAZA PET

Background

Heterogeneity represents one of the main issues in high-grade gliomas (HGGs) management and presumably is the key to understanding treatment failure. Spatial habitat imaging embodies a novel, non-invasive method to cluster different tumor biological microenvironments and characterize intratumoral heterogeneity through a quantitative radiomic approach. So far, habitat imaging has been chiefly explored on morphological magnetic resonance imaging (MRI): the aim of our study was to evaluate this technique on advanced imaging techniques as perfusion (PWI) and diffusion (dMRI) MRI, as well as 18F-FAZA PET, to subdivide the tumor into different biological compartments.

Materials and Methods

A preoperative PWI, dMRI, and 18F-FAZA PET acquisition was obtained in 17 HGG patients to assess intratumoral vascularization, cellularity, and hypoxia, respectively. A tumor mask was created including contrast-enhancing/necrotic regions on T1 imaging and surrounding FLAIR hyperintensity, and each parametric map (plasma volume from dynamic contrast-enhanced PWI, mean diffusivity from diffusion tensor imaging, and standardized uptake value from 18F-FAZA PET) underwent OTSU’s binary clustering by grouping together voxels with high and low-intensity values. Cluster intersections were then generated by combining all possible high and low-intensity regions of each map, and the final habitat map was composed. Habitats’ quantitative features, spatial distribution, and histopathological characteristics were analyzed.

Results

The eight habitats generated were carefully inspected, and their distribution pattern, in relation to morphological landmarks (as contrast-enhancing, necrotic, infiltrative and edematous areas), showed an excellent reproducibility among different HGGs, offering complementary data to conventional imaging. A consistent correlation was noted between each habitat’s awaited microenvironment and the corresponding histopathological characteristics among the ten patients for whom precise coordinates of stereotactic biopsies were available. Clusters considered more aggressive were more represented in WHO grade IV (vs. grade III) tumors. The habitat possibly representing edematous areas was significantly larger in IDH-1 wild-type (vs. IDH-1 mutated) tumors.

Conclusions: PET and MRI hypoxia, perfusion, and tissue diffusion habitat maps proved an excellent reproducibility among HGGs and correlation with expected histopathological features, making it a way to characterize intratumoral heterogeneity. However, further study is needed to elucidate clinical implications and confirm the spatio-temporal evolution of the identified habitats.

Funding

Italian Ministry of Health, grant number GR-2018-12365670; Italian Association for Cancer Research (grant IG 2014 Id.1524).

Repurposing of Anticancer Stem Cell Drugs in Brain Tumors

Brain tumors in adults may be infrequent when compared with other cancer etiologies, but they remain one of the deadliest with bleak survival rates. Current treatment modalities encompass surgical resection, chemotherapy, and radiotherapy. However, increasing resistance rates are being witnessed, and this has been attributed, in part, to cancer stem cells (CSCs). CSCs are a subpopulation of cancer cells that reside within the tumor bulk and have the capacity for self-renewal and can differentiate and proliferate into multiple cell lineages. Studying those CSCs enables an increasing understanding of carcinogenesis, and targeting CSCs may overcome existing treatment resistance. One approach to weaponize new drugs is to target these CSCs through drug repurposing which entails using drugs, which are Food and Drug Administration-approved and safe for one defined disease, for a new indication. This approach serves to save both time and money that would otherwise be spent in designing a totally new therapy. In this review, we will illustrate drug repurposing strategies that have been used in brain tumors and then further elaborate on how these approaches, specifically those that target the resident CSCs, can help take the field of drug repurposing to a new level.

Comparison of T1 mapping and fixed T1 method for dynamic contrast-enhanced MRI perfusion in brain gliomas

OBJECTIVES

To compare dynamic contrast-enhanced MRI (DCE-MRI) data obtained using different prebolus T1 values in glioma grading and molecular profiling.

METHODS

We retrospectively reviewed 83 cases of gliomas: 46 lower-grade gliomas (LGG; grades II and III) and 37 high-grade gliomas (HGG; grade IV). DCE-MRI maps of plasma volume fraction (Vp), extravascular-extracellular volume fraction (Ve), and tracer transfer constant from plasma to tissue (K^trans) were obtained using a fixed T1 value of 1400 ms and a measured T1 obtained with variable flip angle (VFA). Tumour segmentations were performed and first-order histogram parameters were extracted from volumes of interest (VOIs) after co-registration with the perfusion maps. The two methods were compared using Wilcoxon matched-pairs signed-rank test and Bland-Altman analysis. Diagnostic accuracy was obtained and compared using ROC curve analysis and DeLong's test.

RESULTS

Perfusion parameters obtained with the fixed T1 value were significantly higher than those obtained with the VFA. As regards diagnostic accuracy, there were no significant differences between the two methods both for glioma grading and molecular classification, except for few parameters of both methods.

CONCLUSIONS

DCE-MRI data obtained with different prebolus T1 are not comparable and the definition of a prebolus T1 by T1 mapping is not mandatory since it does not improve the diagnostic accuracy of DCE-MRI.

KEY POINTS

• DCE-MRI data obtained with different prebolus T1 are significantly different, thus not comparable. • The definition of a prebolus T1 by T1 mapping is not mandatory since it does not improve the diagnostic accuracy of DCE-MRI for glioma grading. • The use of a fixed T1 value represents a valid alternative to T1 mapping for DCE-MRI analysis.

Dexamethasone-induced upregulation of CaV3.2 T-type Ca2+ channels in rat cardiac myocytes

Glucocorticoids are widely used to treat acute and chronic diseases. Unfortunately, their therapeutic use is associated with severe side effects. Glucocorticoids are known to regulate several ion channels in cardiac myocytes, including voltage-dependent Ca²⁺ channels. Low-voltage-activated T-type Ca²⁺ channels are expressed in ventricular myocytes during the fetal and perinatal period, but are practically absent in the adult. However, these channels can be re-expressed in adult cardiomyocytes under some pathological conditions. We have investigated the glucocorticoid regulation of T-type Ca²⁺ channels in rat cardiomyocytes. Molecular studies revealed that dexamethasone induces the upregulation of Ca_V3.2 mRNA in neonatal rat ventricular myocytes, whereas Ca_V3.1 mRNA is only slightly affected. Patch-clamp recordings confirmed that T-type Ca²⁺ channel currents were upregulated in dexamethasone treated cardiomyocytes, and the addition of 50 μmol/L NiCl₂ demonstrated that the Ca_V3.2 channel is responsible for this upregulation. The effect of dexamethasone on Ca_V3.2 is mediated by the activation and translocation to the cell nucleus of the glucocorticoid receptor (GR). We have isolated the upstream promoter of the Cacna1h gene and tested its activity in transfected ventricular myocytes. The initial in silico analysis of Cacna1h promoter revealed putative glucocorticoid response elements (GREs). Transcriptional activity assays combined with deletion analyses and chromatin immunoprecipitation assays demonstrated that GR binds to a region a GRE located in -1006/-985 bp of Cacna1h promoter. Importantly, upregulation of the Ca_V3.2 channel is also observed in vitro in adult rat ventricular myocytes, and in vivo in a rat model of excess of glucocorticoids.

Hypoxic induction of T-type Ca(2+) channels in rat cardiac myocytes: role of HIF-1α and RhoA/ROCK signalling

T-type Ca(2+) channels are expressed in the ventricular myocytes of the fetal and perinatal heart, but are normally downregulated as development progresses. Interestingly, however, these channels are re-expressed in adult cardiomyocytes under pathological conditions. We investigated low voltage-activated T-type Ca(2+) channel regulation in hypoxia in rat cardiomyocytes. Molecular studies revealed that hypoxia induces the upregulation of Cav 3.2 mRNA, whereas Cav 3.1 mRNA is not significantly altered. The effect of hypoxia on Cav 3.2 mRNA was time- and dose-dependent, and required hypoxia inducible factor-1α (HIF-1α) stabilization. Patch-clamp recordings confirmed that T-type Ca(2+) channel currents were upregulated in hypoxic conditions, and the addition of 50 μm NiCl2 (a T-type channel blocker) demonstrated that the Cav 3.2 channel is responsible for this upregulation. This increase in current density was not accompanied by significant changes in the Cav 3.2 channel electrophysiological properties. The small monomeric G-protein RhoA and its effector Rho-associated kinase I (ROCKI), which are known to play important roles in cardiovascular physiology, were also upregulated in neonatal rat ventricular myocytes subjected to hypoxia. Pharmacological experiments indicated that both proteins were involved in the observed upregulation of the Cav 3.2 channel and the stabilization of HIF-1α that occurred in response to hypoxia. These results suggest a possible role for Cav 3.2 channels in the increased probability of developing arrhythmias observed in ischaemic situations, and in the pathogenesis of diseases associated with hypoxic Ca(2+) overload.

Non-alcoholic fatty liver disease and hepatocellular carcinoma in a 7-year-old obese boy: coincidence or comorbidity?

BACKGROUND

Hepatocellular carcinoma (HCC) may develop from non-alcoholic fatty liver disease (NAFLD) either in the presence or in the absence of established cirrhosis. Non-cirrhotic patients with NAFLD-related HCC are usually adult, male and obese. However, this association has not been reported yet in younger age groups. Objectives In the present study, the clinical case of a 7-yaer-old obese boy with steatosis and HCC is presented.

METHODS

A 7-year-old boy, with no evidence of chronic liver disease, was admitted for assessment of a liver mass. Preliminary assessment was suggestive of a combined and severe liver steatosis together with a malignant disease.

RESULTS

A biopsy confirmed the suspected diagnosis of HCC; interestingly, the non-neoplastic liver was surrounded and characterized by the presence of steatosis and ballooning, and being absent of lobular inflammation and fibrosis. Chemotherapy and diet changes were conducted successfully with ultrasound characteristics suggesting improvements on both aspects: conventional liver mass resection could take place.

CONCLUSIONS

This case report suggests that HCC might develop in paediatric age patients with obesity-related NAFLD, even in the absence of fibrosis.

Galectin-3 is a marker of favorable prognosis and a biologically relevant molecule in neuroblastic tumors

Childhood neuroblastic tumors are characterized by heterogeneous clinical courses, ranging from benign ganglioneuroma (GN) to highly lethal neuroblastoma (NB). Although a refined prognostic evaluation and risk stratification of each tumor patient is becoming increasingly essential to personalize treatment options, currently only few biomolecular markers (essentially MYCN amplification, chromosome 11q status and DNA ploidy) are validated for this purpose in neuroblastic tumors. Here we report that Galectin-3 (Gal-3), a β-galactoside-binding lectin involved in multiple biological functions that has already acquired diagnostic relevance in specific clinical settings, is variably expressed in most differentiated and less aggressive neuroblastic tumors, such as GN and ganglioneuroblastoma, as well as in a subset of NB cases. Gal-3 expression is associated with the INPC histopathological categorization (P<0.001) and Shimada favorable phenotype (P=0.001), but not with other prognostically relevant features. Importantly, Gal-3 expression was associated with a better 5-year overall survival (P=0.003), and with improved cumulative survival in patient subsets at worse prognosis, such as older age at diagnosis, advanced stages or NB histopathological classification. In vitro, Gal-3 expression and nuclear accumulation accompanied retinoic acid-induced cell differentiation in NB cell lines. Forced Gal-3 overexpression increased phenotypic differentiation and substrate adherence, while inhibiting proliferation. Altogether, these findings suggest that Gal-3 is a biologically relevant player for neuroblastic tumors, whose determination by conventional immunohistochemistry might be used for outcome assessment and patient's risk stratification in the clinical setting.

Wettability control by laser texturing process generating localized gold nanoparticles on polymeric thin films

In this work a new approach is introduced for surface properties control by laser texturing process. By UV laser irradiation, we are able to control the surface wettability of a chitosan polymeric film in which is introduced a chloroauric acid salt by immersion. Specifically the UV irradiation is responsible for the creation of gold nanoparticles at the irradiated surface of the polymeric film. This photolytic process allows us to localize and design accurately surface patterns and moreover to tune metallic particle size in the range of nanoscale. After the characterization of our gold textured surfaces by atomic force and scanning electron microscopies, we demonstrate the link between wettability surface properties and gold nanoparticles size. The experimental results indicate the influence of the laser intensity, the irradiation time and the polymer film thickness (by increasing the gold concentration) on the gold nanoparticle density and size.

Predictive value of inferior fronto-occipital fasciculus (IFO) DTI-fiber tracking for determining the extent of resection for surgery of frontal and temporal gliomas preoperatively

AIM

This work reports the analysis of the relationship between inferior fronto-occipital fasciculus (IFO), neoplastic lesions and surgical resection, in patients operated for gliomas located in the frontal, temporal and insular lobes of the dominant hemisphere. Aim of the study is evaluating the predictive value of inferior fronto-occipital fasciculus DTI-fiber tracking (FT) for determining the extent of resection preoperatively.

METHODS

We selected 38 cases affected by lesions located in the frontal, temporal and insular lobes of the dominant hemisphere, which were related to the trajectory of the IFO. For each patient preoperative and postoperative MR images and DTI-FT were loaded into the neuronavigation system and merged; volumetric scan analysis was used for establishing tumor location and topography, as well as the volume of the lesion and of the residual tumor. All preoperative fiber tracking datasets were evaluated and the position of the tract (IFO) compared to the tumor was recorded. Postoperative MR scans were then compared with DTI-FT, in order to evaluate the correspondence between the resection boundaries and the trajectory of the fiber tract.

RESULTS

Amongst the cases in which the IFO was inside the lesion, we found only incomplete resections (5 subtotal and 6 partial resections), while considering the cases in which the IFO was located outside the tumor, it was possible to perform a relevant (total/subtotal) resection in 18 of them (78%).

CONCLUSION

FT of the inferior frontal-occipital fasciculus predicts the possibility and the extent of the resection for a frontal, temporal and/or insular lesion of the dominant hemisphere.

Effects of multiple courses of oral gefitinib, topotecan, and cyclophosphamide in poor risk neuroblastoma

20009

Background: Gefitinib (G) has shown potent inhibitory activity on neuroblastoma (NB) cell proliferation in in vitro models. Experimental data have also reported that the addition of G to cytotoxic drugs can increase in vitro and in vivo antitumor activity in several tumor models, but if this will translate in significant clinical benefits, with respect to survival, is still unclear. We evaluated the feasibility of administering an oral regimen including G combined with topotecan (TPT) and cyclophosphamide (CPA) in heavily pretreated pts with relapsed/resistant metastatic NB. Methods: Patients received oral CPA (50 mg/m2/day) followed by TPT (0.8 mg/m2/day) plus G (at the fixed dose of 250 mg/day) for 14 consecutive days in an outpatient setting. Courses were repeated every 28 days until progression, and response was evaluated every second course. Expression of EGFR mRNA in primary tumors was assessed by real-time RT-PCR. Results: Six pts (1M/5F), median age 5.4 years (range 4.1–8.2), were enrolled between October 2004 and October 2006. All pts were relapsed after high-dose chemotherapy and hemopoietic rescue with PBSCs. At the time of inclusion, 3 pts were in PR after 8 courses of second-line therapy, whilst 2 pts had achieved SD after 1 and 8 courses of second-line therapy, resp; 1 pt had PD right after PBSC rescue. Significant levels of EGFR mRNA were detected in 4/6 tumors. A median of 7.5 courses (range 1–24) per pt were administered. In 4 pts, the dose of TPT and CPA was reduced by 25% after the first course. After a median follow-up of 12 months (range 1–26), 1 pt is DOD at 15 months since the inclusion and 5 pts are alive, 1 in VGPR (26+ months) and 5 with SD (26+, 1+, 4+, 9+ and 18+ months). Median PFS is 7.5 months (range 1–26). Neutropenia grade 4 was observed in 4/6 pts; rash grade 2 in 2 pts, and hepatic (LFT increase) grade 3 toxicity in 1. Conclusions: The regimen was feasible and well tolerated in this series of heavily pretreated pts. PFS is encouraging, but deserves further evaluation and longer follow-up. Additional molecular studies are ongoing aimed at identifying the subset of NB pts most likely to benefit from the synergy between G and cytotoxic drugs observed in preclinical models.

No significant financial relationships to disclose.

Temozolomide in resistant or relapsed pediatric solid tumors

PURPOSE

We report the off-label study aimed at investigating the use of temozolomide (TMZ) as single agent in relapsed or resistant pediatric solid tumors. The drug was administered at the dose of 215 mg/m2/day x 5 days or 180 mg/m2/day x 5 days in patients with prior craniospinal irradiation (CSI) or autologous bone marrow transplantation (ABMT).

PATIENTS AND METHODS

Fifty two patients, median age 127.6 months, with resistant or relapsed solid tumors were enrolled. Tumor types were: neuroblastoma (NB; n = 17), medulloblastoma (MB; 8), brain stem glioma (BSG; 8), extraosseous Ewing's sarcoma/peripheral neuroectodermal tumor (EOES; 4), Ewing's sarcoma (ES; 4), anaplastic astrocytoma (AA; 3), rhabdomyosarcoma (RMS; 2), ependymoma (EP; 2), cerebral primitive neuroectodermal tumor (cPNET; 2), hepatocarcinoma (HC; 1), and osteosarcoma (OS; 1). All patients were pre-treated. Two outpatient courses were administered, with a median of 4.8 courses/pt.

RESULTS

Objective response-rate (CR + PR + MR) in our series was 13.4% (1.9% CR, 3.8% PR, and 7.7% MR), SD occurred in 38.4% of patients and 48% had PD. The median survival was 7.8 months (range 1-37) and median time to progression was 3.4 months (range 1-20); these data were significantly correlated with histology and previous nitrosureas administration in multivariate analysis. Haematological toxicity grade 3-4 (mainly thrombocytopenia) was observed in 21.4% of administered courses, nausea was reported in 3.1% and respiratory distress in 0.7%.

CONCLUSION

Oral TMZ was well tolerated in children with resistant or relapsed solid tumors and showed activity in NB and CNS tumours refractory to standard chemotherapy.

[Diarrhoea in the traveller]

Diarrhoeic diseases caused by water and food contaminated by enteropathogens continue to be an important cause of morbidity in countries with a low level of development. Some 50,000 cases of diarrhoea in travellers are estimated in the world every day, and this is the main cause of consultation by travellers who return from undeveloped zones. The principal determinant of risk is the place of destination; there are significant differences between different regions with respect to risk and to the aetiology of the diarrhoea. The most frequent cause of diarrhoeas is of bacterial origin, which represents between 60 and 85% of the cases, while parasites represent 10% and some 5% are produced by viruses. Although it normally follows a benign course, complications can arise, with mortality being only exceptionally associated to this disease. Prevention is essentially based on strictly following elemental hygienic measures and avoiding the ingestion of foodstuffs and drinks with a risk of contamination. Prophylaxis with antibiotics is only advisable in journeys of short duration, in which the risk and/or seriousness of diarrhoeas, above all in immunosuppressed patients, are higher than the possible collateral effects. The treatment of diarrhoea in the traveller is based on adequate hydration, and the use of microbians is reserved for moderate and serious situations, with quinolones being the drug of choice. Rifaximine is a new drug approved for the treatment of diarrhoeas in the traveller, above all in areas with enteropathogens that are resistant to quinolones.

The inflammatory reaction in human traumatic oedematous cerebral cortex

The inflammatory reaction surrounding hemorrhagic and perihematomal brain parenchyma has been studied by means of light and transmission electron microscopy in 12 patients with severe traumatic head injuries complicated with subdural or extradural hematoma or hygroma. Perivascular cells, ameboid phagocytic microglial cells, and infiltrated macrophage/monocyte system were observed surrounding perivascular and intraparenchymal hemorrhagic foci. They showed phagocytic activity of degenerated nerve cell processes, and organized proteinaceous edema fluid present in the enlarged extracellular space. Endocytosis by means of clathrin coated vesicles also was observed. Facultative and professional phagocytes exhibited a full repertoire of lysosomes, phagosomes containing nerve cell debris, lipid droplets, and lipofucsin granules. Phagocytic pericytes remaining within the capillary basement membrane were also observed around perivascular hemorrhages. The inflammatory reaction was examined in young and old patients with an evolution time of brain injury ranging from 1 day to 2 years. The inflammatory process developed according to the intensity of traumatic insult, patient age, associated hematoma or hygroma, severity of vasogenic and cytotoxic oedema, and anoxic-ischemic conditions of brain parenchyma.

Ifosfamide/carboplatin/etoposide (ICE) as front-line, topotecan/cyclophosphamide as second-line and oral temozolomide as third-line treatment for advanced neuroblastoma over one year of age

Children affected by advanced neuroblastoma have a discouraging prognosis, but intensive induction chemotherapy may increase the complete response rate. The combination of ifosfamide, carboplatin and etoposide (ICE) was used for the first time as front-line regimen in patients with stage 4 neuroblastoma over the age of 1 y. Similarly, second-line treatment for children with relapsed neuroblastoma, particularly after high-dose chemotherapy, has been unsatisfactory. The combination of topotecan and cyclophosphamide was studied in resistant or relapsed solid tumors. Furthermore, there is a need for effective palliative treatment in patients failing therapy. Temozolomide, a new dacarbazine analog with optimal oral bioavailability, is being used in an ongoing phase II study as an alternative to oral etoposide. Seventeen patients with stage 4 neuroblastoma have entered the ICE study; 15/16 (94%) major responses after induction were observed and 6/16 (37%) evaluable patients are disease free after a median of 51 mo. Twenty-one patients with relapsed/refractory disease (of whom 13 neuroblastomas) entered the topotecan/cyclophosphamide study: 7/21 (33%) patients responded. Forty-one patients entered the temozolomide study (of whom 16 had neuroblastomas): stable disease and symptom relief were obtained in 15/30 (50%) evaluable patients. Intensive induction with ICE resulted in a faster response with high response rate; a larger study with longer follow-up is needed to confirm a survival advantage. Second-line treatment was effective in obtaining remissions, some of them long lasting. Third-line treatment did not elicit measurable responses in neuroblastoma, but achieved prolonged freedom from disease progression and excellent palliation in several patients.

Transmission electron microscopy of cortical dendritic spines in the human oedematous cerebral cortex

The cortical biopsies of 31 patients with clinical diagnosis of congenital hydrocephalus, vascular anomalies, brain tumours and brain trauma were examined with the transmission electron microscope. A variety of swollen spine shapes were found: mushroom shaped, filopodic, lanceolated spines, and megaspines. The spines appeared axonless or making asymmetric synaptic contacts with swollen presynaptic axons. They exhibited a disrupted actin-like network, dilated endoplasmic reticulum profiles, oedematous clear or dense mitochondria, and clusters of free ribosomes. Some spines contained a hypertrophic cytoskeleton. The spine apparatus appeared generally swollen with clear and dilated cisterns. In severe brain trauma and tumours some spine apparatus appeared disorganised or atrophic. In complicated brain trauma with subdural haematoma or hygroma some degenerated spines displayed a high electron density. The ultrastructural findings suggest that alterations of the spines are responsible for the neurological symptoms exhibited by some patients, which imply a disturbance of cortical nerve circuits. The presence of axonless spines is symptomatic of a loss of nerve connectivity, and are expected to have a significant input on neurological and mental functions.

Correlative microscopy of Purkinje dendritic spines: a field emission scanning and transmission electron microscopic study

Purkinje dendritic spines (Pds) of mouse cerebellar cortex were examined by field emission scanning electron microscopy (FESEM) and by transmission electron microscopy (TEM) using ultrathin sections and freeze-etching replicas, to study their three-dimensional features and intramembrane morphology. FESEM showed unattached mushroom-type, elongated and lanceolate Pds separated by 100-500 nm on the dendritic shaft surface. High resolution FESEM showed 25-50 nm globular subunits at the spine postsynaptic density corresponding to the localization of postsynaptic proteins and/or postsynaptic receptors. TEM images of ultrathin sections showed gem-like, mushroom-shaped, lanceolate and neckless or stubby spines. Freeze etching replicas exposed postsynaptic intramembrane particles that can be correlated with the globular subunits observed at high resolution FESEM. Parallel and climbing fiber endings were observed making asymmetric synaptic contacts with the Pds heads. Simultaneous contacts with the necks and heads were also found. The variety of Pds shapes were interpreted as spine conformational changes related with spine dynamic, and spine plasticity.

Electron microscopy of umbilical cord endothelial cells in preeclampsia

We have studied by means of transmission electron microscopy the umbilical cord endothelial cells in 11 preeclamptic women. Endothelial cells exhibited oval, round, elongated, flattened, triangular or polygonal shapes. The nuclei displayed shallow and deep invaginations of nuclear envelope. The endoplasmic reticulum appeared highly dilated and vacuolated. The swollen mitochondria showed cristae fragmentation. Areas of focal necrosis were appreciated throughout the cytoplasm. A marked enlargement of subendothelial space and the presence of an electron dense granular material were also found. The findings reveal activation and injury of endothelial cells and disruption of endothelial cell layer.

Consecutive light microscopy, scanning-transmission electron microscopy and transmission electron microscopy of traumatic human brain oedema and ischaemic brain damage

Cortical biopsies of 11 patients with traumatic brain oedema were consecutively studied by light microscopy (LM) using thick plastic sections, scanning-transmission electron microscopy ((S)TEM) using semithin plastic sections and transmission electron microscopy (TEM) using ultrathin sections. Samples were glutaraldehyde-osmium fixed and embedded in Araldite or Epon. Thick sections were stained with toluidine-blue for light microscopy. Semithin sections were examined unstained and uncoated for (S)TEM. Ultrathin sections were stained with uranyl and lead. Perivascular haemorrhages and perivascular extravasation of proteinaceous oedema fluid were observed in both moderate and severe oedema. Ischaemic pyramidal and non-pyramidal nerve cells appeared shrunken, electron dense and with enlargement of intracytoplasmic membrane compartment. Notably swollen astrocytes were observed in all samples examined. Glycogen-rich and glycogen-depleted astrocytes were identified in anoxic-ischaemic regions. Dark and hydropic satellite, interfascicular and perivascular oligodendrocytes were also found. The status spongiosus of severely oedematous brain parenchyma observed by LM and (S)TEM was correlated with the enlarged extracellular space and disrupted neuropil observed by TEM. The (S)TEM is recommended as a suitable technique for studying pathological processes in the central nervous system and as an informative adjunct to LM and TEM.

[Abdominal pain in childhood: multidisciplinary approach. A clinical case]

The Authors describe a case of mature cystic teratoma found in a little girl 9 + 8/12 years old and removed in laparoscopic way. Various specialists' contribution shows up for the resolution of the case.

Oligodendroglial cell damage and demyelination in infant hydrocephalus. An electron microscopic study

The hydropic changes of oligodendroglial cells have been examined by means of transmission electron microscopy in seventeen cases of human, mostly infant hydrocephalus and associated pathology. Hydropic oligodendrocytes exhibited dilated endoplasmic reticulum and nuclear envelope, edematous mitochondria, enlarged and fragmented Golgi complexes, dense bodies and nuclear chromatin homogenization. A process of nuclear pore disassembly, extrusion of nuclear heterochromatin and an apoptotic-like process were observed in some swollen oligodendrocytes. Some resting or quiescent oligodendrocytes were also observed in the edematous neuropil. Oligodendrocyte cell processes appeared atrophic, degenerated and isolated in the enlarged extracellular spaces. They did not show any association with neighbouring axons, and myelinated axons were not observed in the neuropil. These observations suggest demyelination in infant hydrocephalus.

[Morbidity of childhood bronchial asthma in the emergency room]

BACKGROUND

An allergic etiology could be found in more than the 80% of the patients with bronchial asthma. Specific immunotherapy is the only known etiologic treatment, reducing clinical symptoms and requirement of medication. However only a few patients are controlled by an allergist. The aim of the present study was to verify the influence of control and treatment carried out by patients in childhood asthma recruitment that came to the emergency room of our hospital (Hospital Clínico San Carlos) between December 95 and June 96.

MATERIAL AND METHOD

Children to 15 years old were included in the study. We analysed: age, sex, clinical record, previous treatment (pharmacological and etiological), basal symptoms, necessity to be admitted to hospital, medical previous control.

RESULTS

163 patients came to emergency room because of asthma exacerbation. They were divided in two groups: less than 3 years (average 17.45 months) and more than 3 years (average 8 years) (Sd: 3.4). Sex: 65% male sex and 35% female sex. 44.17% came during the greater pollinization period in our field, with a statistical significance compared with other periods (p: 0.0023). 81 patients (49.7%) had been previously diagnosed of bronchial asthma. 15% of the patients were controlled by an allergist, with a stable situation in 92% of them. 68.4% of patients who were controlled by a paediatrician and 40% who were controlled in a officially approved centre (p: 0.015) were stable. 55 patients had continuous treatment and 21.8% of them were been treated with immunotherapy. 17.7% of patients without immunotherapy were admitted to hospital. None of the patients on immunotherapy were hospitalised.

CONCLUSIONS

It is essential to do an early diagnosis and a combined follow-up by an allergist and a paediatrician to succeed in a good control of the disease from its beginning. In our experience, the children who were controlled by an allergist had a more stable situation and were also more easily controlled. The specific treatment should be initiated in the early stage of the disease being the only factor that modify the immune response and prevents against the development of asthma in children with rhinitis.

Predicting the result of noninvasive ventilation in severe acute exacerbations of patients with chronic airflow limitation

OBJECTIVE

To analyze prospectively the factors related to the success of noninvasive ventilation (NIV) in the treatment of acute exacerbations of chronic airflow limitation (CAFL) and to generate a multiple regression model in order to detect which patients can be successfully treated by this method.

SETTING

A respiratory medicine ward of a referral hospital.

METHODS AND PRINCIPAL RESULTS

Initially, we examined 44 episodes of acute respiratory failure in 36 patients with CAFL in whom mechanical ventilation was advisable. In 34 of 44 episodes (77%), NIV was used successfully. Patients in whom NIV succeeded had a lower FEV(1) prior to admission, a higher level of consciousness (LC), and significant improvements in PaCO(2), pH, and LC after 1 h of NIV. A logistic regression model consisting of baseline FEV(1) and PaCO(2) values, initial PaCO(2), pH, and LC values on admission, and PaCO(2) values after 1 h of NIV allowed us to correctly classify > 95% of the 44 episodes in which the outcome was successful. In the second part of the study, we prospectively validated the equation in another 15 consecutive CAFL patients with acute hypercapnic respiratory failure. NIV successfully treated 12 patients (80%), and the model correctly classified 14 patients (93%).

CONCLUSION

Good LC at the beginning of NIV and improvements in pH, PaCO(2), and LC values after 1 h of NIV are associated with successful responses to NIV in COPD patients with acute hypercapnic respiratory failure. Our validated multiple regression model confirms that these variables predict the result of NIV in acute hypercapnic failure in CAFL patients.

A small domain in the N terminus of the regulatory alpha-subunit Kv2. 3 modulates Kv2.1 potassium channel gating

Recent work has demonstrated the existence of regulatory K(+) channel alpha-subunits that are electrically silent but capable of forming heterotetramers with other pore-forming subunits to modify their function. We have investigated the molecular determinant of the modulatory effects of Kv2.3, a silent K(+) channel alpha-subunit specific of brain. This subunit induces on Kv2.1 channels a marked deceleration of activation, inactivation, and closing kinetics. We constructed chimeras of the Kv2.1 and Kv2.3 proteins and analyzed the K(+) currents resulting from the coexpression of the chimeras with Kv2.1. The data indicate that a region of 59 amino acids in the N terminus, adjacent to the first transmembrane segment, is the major structural element responsible for the regulatory function of Kv2.3. The sequence of this domain of Kv2.3 is highly divergent compared with the same region in the other channels of the Kv2 family. Replacement of the regulatory fragment of Kv2.3 by the equivalent of Kv2.1 leads to loss of modulatory function, whereas gain of modulatory function is observed when the Kv2.3 fragment is transferred to Kv2.1. Thus, this study identifies a N-terminus domain involved in Kv2.1 channel gating and in the modulation of this channel by a regulatory alpha-subunit.

Transient muteness followed by dysarthria in patients with pontomesencephalic stroke. Report of two cases

Dysarthria is the principal motor abnormality following vascular damage to pontine paramedian structures, owing to the involvement of corticobulbar fibres. Here we describe 2 cases of adults affected by dysarthria following transient muteness as the result of a stroke in pontomesencephalic structures. Their clinical outcome was very similar to that of young patients who have undergone surgery of the 4th ventricle. Recently the importance of pons involvement has also been underlined in these cases. This case report suggests the existence of a functional network for speech, in which the pontomesencephalon is an important station for the triggering and the efficacy of verbal production.

Proximal and distal gastric distension in normal subjects and H. pylori-positive and -negative dyspeptic patients and correlation with symptoms

Aim of the study was to analyze gastric distension with water in H. pylori-positive and -negative dyspeptic patients and normal subjects and the correlation with symptoms. Twenty dyspeptic patients and 19 normal subjects were studied. H. pylori was determined in each dyspeptic patient with the rapid urea test at endoscopy. Gastric distension was evaluated by real-time ultrasonography with the ingestion of stepwise-increasing amounts of water up to a total of 600 ml. During distension, the symptom score was evaluated as well. The proximal stomach was significantly smaller in dyspeptic patients than in healthy controls, at 100-600 ml water (P<0.01). A larger distal stomach was observed at 500 and 600 ml of water (P<0.01). The score of bloating and fullness was greater in dyspeptics than in controls at 300 and 600 ml of water distension. The symptoms score was linearly correlated with proximal and distal gastric measurements in dyspeptic patients and in controls. No significant difference was found in dyspeptic patients regarding the H. pylori status. In conclusion, dyspeptic patients show a defective adaptation of the whole stomach to water distension and an increased symptom perception score as compared to controls. H. pylori infection does not seem to be a determining factor in these observed findings.

[The laparoscopic surgical therapy of gastroesophageal reflux disease]

Between January 1995 and February 1997 we performed 30 laparoscopic Nissen-Rossetti fundoplications and 3 laparotomic Nissen fundoplications. All patients were suffering from gastro-esophageal reflux disease (GERD) resistant to medical therapy, 19 patients were suffering also from hiatal hernia and 2 pz. were suffering from a para esophageal hernia. 1 patient had been previously treated with laparotomic Nissen fundoplication for GERD and hiatal hernia. Preoperative assessment included: oesophagogastroduodenoscopy (EGDS) with biopsies: 24-h pH-monitoring; 24-h manometry; barium swallow and DeMeester symptoms scoring. Mean operation time was 110 min. 1 pz. required conversion to laparotomy. 35% of pz. experienced mild grade dysphagia that resolved spontaneously in 4-8 weeks. Postoperative evaluation was performed in all patients 6 months after surgery. Overall results were characterised by a significant reduction of the symptoms score: mean score was reduced from 5.6/9 to 0/9. No signs of oesophagitis were seen at control EGDS. 24-h pH monitoring demonstrated a significant reduction of the total time at ph < 4 from a mean value of 28.2% preoperatively to 1.9% postoperatively. 24 h oesophageal manometry revealed a rise in lower oesophageal sphincter pressure from a mean of 11 mmHg preoperatively to a mean of 27 mmHg postoperatively. Our preliminary results demonstrate that laparoscopic Nissen-Rossetti fundoplication is a safe and effective procedure for gastro-oesophageal reflux disease but, sometimes, laparotomic technique can be considered in selected cases.

Shortened time to recovery from chemotherapy induced neutropenia in pediatric patients with high dose combined cytokines

Granulocyte colony stimulating factor (G-CSF) and granulocyte macrophage colony stimulating factor (GM-CSF) are cytokines which have been extensively administered as monotherapy to patients with a variety of hematopoietic disorders at dosages of 5 mcg/kg/day. Because their spectrum of activity is both singular and simultaneously overlapping, we postulated that combined therapy would be more advantageous than monotherapy. Since 1992 we have carried out a study of G-CSF and GM-CSF as monotherapy or in combination in pediatric patients with solid tumors following chemotherapy induced nadirs of 0-800 WBC/mm3. When combined, the cytokines were given twice per day at 2.5 or 5.0 mcg/kg. For the monotherapy groups, either cytokine at 5 mcg/kg or 10 mcg/kg was given once daily. The mean time to recovery from neutropenia nadir ranged from 6.6-8.2 days in patients receiving a total of 10 mcg/kg/day compared to 10.4-10.6 days in patients treated with 5 mcg/kg/day. Side effects were ephemeral eosinophilia. The dosage of 10 mcg/kg/day appears to be a better dosage for pediatric patients with a slight advantage in the combined twice a day schedule (6.6 days).

Identification and functional characterization of a K+ channel alpha-subunit with regulatory properties specific to brain

The physiological diversity of K+ channels mainly depends on the expression of several genes encoding different alpha-subunits. We have cloned a new K+ channel alpha-subunit (Kv2.3r) that is unable to form functional channels on its own but that has a major regulatory function. Kv2.3r can coassemble selectively with other alpha-subunits to form functional heteromultimeric K+ channels with kinetic properties that differ from those of the parent channels. Kv2.3r is expressed exclusively in the brain, being concentrated particularly in neocortical neurons. The functional expression of this regulatory alpha-subunit represents a novel mechanism without precedents in voltage-gated channels, which might contribute to further increase the functional diversity of K+ channels necessary to specify the intrinsic electrical properties of individual neurons.