Atomic force microscopy imaging using a tip-on-chip: opening the door to integrated near field nanotools

We describe in detail how atomic force microscopy (AFM) images can be routinely achieved with macroscopic silicon-based chips integrating mesoscopic tips, paving the way for the development of new near field devices combining AFM imaging with any kind of functionality integrated on a chip. The chips have been glued at the end of the free prong of 100 kHz quartz tuning forks mounted in Qplus configuration. Numerical simulations by modal analysis have been carried out to clarify the nature of the vibration modes observed in the experimental spectra. It is shown that two low frequency modes can be used to drive the system and scan the surface with a great stability in amplitude modulation as well as in frequency modulation AFM under ultrahigh vacuum. The AFM capabilities are demonstrated through a series of examples including phase and dissipation contrast imaging, force spectroscopy measurements, and investigations of soft samples in weak interaction with the substrate. The lateral resolution with the tips grown by focused ion beam deposition already matches the one achieved in standard amplitude modulation mode AFM experiments.

Nuclear factor I regulates brain fatty acid-binding protein and glial fibrillary acidic protein gene expression in malignant glioma cell lines

Glial fibrillary acidic protein (GFAP), an intermediate filament protein normally found in astrocytes, and the radial glial marker brain fatty acid-binding protein (B-FABP; also known as FABP7) are co-expressed in malignant glioma cell lines and tumors. Nuclear factor I (NFI) recognition sites have been identified in the B-FABP and GFAP promoters, and transcription of both genes is believed to be regulated by NFI. Here, we study the role of the different members of the NFI family in regulating endogenous and ectopic B-FABP and GFAP gene transcription in human malignant glioma cells. We show by gel shifts that all four members of the NFI family (NFIA, NFIB, NFIC, and NFIX) bind to B-FABP and GFAP NFI consensus sites. Over-expression of NFIs, in conjunction with mutation analysis of NFI consensus sites using a reporter gene assay, supports a role for all four NFIs in the regulation of the GFAP and B-FABP genes. Knock-down of single or combined NFIs reveals promoter-dependent and promoter-context-dependent interaction patterns and suggests cross talk between the different members of the NFI family. Our data indicate that the NFI family of transcription factors plays a key role in the regulation of both the B-FABP and GFAP genes in malignant glioma cells.

Validity, reliability, and responsiveness of a new short Visual Simplified Respiratory Questionnaire (VSRQ) for health-related quality of life assessment in chronic obstructive pulmonary disease

The Visual Simplified Respiratory Questionnaire (VSRQ) was designed to assess health-related quality of life (HRQoL) in patients with chronic obstructive pulmonary disease (COPD). It contains eight items: dyspnea, anxiety, depressed mood, sleep, energy, daily activities, social activities and sexual life. Psychometric properties were assessed during a clinical trial that evaluated the impact of tiotropium on HRQoL of COPD patients. These included the determination of structure, internal consistency reliability, concurrent validity with the St George's Respiratory Questionnaire (SGRQ), test - retest reliability, clinical validity and responsiveness to change over two weeks. Minimal important difference (MID) was calculated; cumulative response curves (CRC) were based on the dyspnea item. Psychometric analyses showed that VSRQ structure was unidimensional. The questionnaire demonstrated good internal consistency reliability (Cronbach's alpha = 0.84), good concurrent validity with SGRQ (Spearman = -0.70) and clinical validity, good test-retest reproducibility (ICC = 0.77), and satisfactory responsiveness (standardized response mean = 0.57; Guyatt's statistic = 0.63). MID was 3.4; CRC median value of the 'minimally improved' patients was 3.5. In conclusion, VSRQ brevity and satisfactory psychometric properties make it a good candidate for large studies to assess HRQoL in COPD patients. Further validation is needed to extend its use in clinical practice.

Effect of tiotropium on health-related quality of life as a primary efficacy endpoint in COPD

Clinical manifestations of chronic obstructive pulmonary disease (COPD), including airflow limitation, dyspnea, and activity limitation, ultimately lead to impaired health-related quality of life (HRQoL). This 9-month, randomized, double-blind, multicenter study compared the effect of once-daily tiotropium 18 microg and placebo on HRQoL, spirometric parameters, and exacerbations in 554 patients with moderate-to-severe COPD. HRQoL was assessed using the St. George's Respiratory Questionnaire (SGRQ) and the new 8-item Visual Simplified Respiratory Questionnaire (VSRQ), which is currently being validated. The primary efficacy endpoint was the proportion of patients achieving a reduction of at least 4 units in the SGRQ total score at study end (Month 9). Mean +/- SD baseline SGRQ total score was 47.4 +/- 18.1. Significantly more tiotropium-treated patients achieved a reduction of at least 4 units in the SGRQ score vs placebo at study end (59.1% vs 48.2%, respectively; p = 0.029). Tiotropium significantly improved spirometric parameters (forced expiratory volume in 1 second [FEV1]: 0.11 +/- 0.02 L vs 0.01 +/- 0.02 L; between-group difference: 0.10 +/- 0.03 L, p = 0.0001) and reduced exacerbations vs placebo. Maintenance treatment with tiotropium provided significant and clinically relevant improvements in HRQoL, as measured by the SGRQ.

[Prognostic value of MR in term neonates with neonatal hypoxic-ischemic encephalopath: MRI score and spectroscopy. About 26 cases]

Neonatal hypoxic-ischemic encephalopathy remains a major cause of chronic disability in childhood. Early diagnosis and prognosis are necessary for the clinician to adapt the treatment. However, there is yet no reliable test to predict the patient's evolution.

OBJECTIVE

The aim of our study was to evaluate the predictive value of a personal magnetic resonance imaging (MRI) scoring system and of magnetic resonance spectroscopy (MRS).

MATERIAL AND METHODS

We included 26 term newborns in condition of neonatal brain suffering. MR examination was performed during the first week of life for all patients and MRI and MRS data were collected. Standardised follow-up visits were made for all patients. Finally, prognostic value of the different criteria was evaluated with statistical tests.

RESULTS

Our MRI scoring system proved to be linked to prognosis. A high MRI score, abnormal signal in the internal capsule, white matter or basal ganglia abnormalities with diffusion imaging were associated with unfavourable outcome. These results confirmed the data of the literature concerning the MRI predictive value. Our study also confirmed prognostic interest of MR: particularly, ratios using lactate were significantly linked to prognosis in our study. Specificity of the elevation of these ratios was interesting but sensibility was less optimal.

CONCLUSION

We suggest using our MRI scoring system which associates standard MRI and diffusion imaging, which is significantly related to outcome. We confirm the prognostic value of MRS in this pathological situation. MR with diffusion sequence and spectroscopy, performed three to four days after birth appears to be an essential tool to manage these patients.

Constitutive nitric oxide synthase gene polymorphisms and house dust mite respiratory allergy in an Algerian patient group

Genetic polymorphisms in neuronal nitric oxide synthase (NOS1) and calmodulin-dependent endothelial NOS (NOS3) genes are known to influence the course of allergic respiratory disorders. We investigated the role of NOS1 -84 G-->A and NOS3 -786 T-->C, 894 G-->T and 27 base pair (bp) repeat polymorphisms in 125 patients suffering from asthma and/or rhinitis and monosensitized against Dermatophagoides pteronyssinus (Dpter) and 111 controls from Algeria. We found a higher frequency of the -786 C NOS3 allele in patients than in controls [corrected P value (Pc) = 0.04], especially in female cases (Pc = 0.02) and that the 'ab' genotype of the 27-bp polymorphism was significantly associated with specific immunoglobulin E production against Dpter (P = 0.006). This study brings further support for the participation of NOS3 gene polymorphism in the pathogenesis of respiratory allergic disorders.

Anomalous resistance ridges along filling factor nu=4i

We report anomalous structure in the magnetoresistance of SiO(2)/Si(100)/SiO(2) quantum wells. When Landau levels of opposite valleys are driven through coincidence at the Fermi level, the longitudinal resistance displays elevations at filling factors that are integer multiples of 4 (nu=4i) accompanied by suppression on either side of nu=4i. This persists when either the magnetic field or the valley splitting is swept, leading to resistance ridges running along nu=4i. The range of field over which they are observed points to the role of spin degeneracy, which is directly confirmed by their disappearance with the addition of an in-plane magnetic field. The data suggest a new type of many-body effect arising from the combined degeneracy due to the valley and the spin degrees of freedom.

Surface plasmon mediated near-field imaging and optical addressing in nanoscience

We present an overview of recent progress in "plasmonics". We focus our study on the observation and excitation of surface plasmon polaritons (SPPs) with optical near-field microscopy. We discuss in particular recent applications of photon scanning tunnelling microscope (PSTM) for imaging of SPP propagating in metal and dielectric wave guides. We show how near-field scanning optical microscopy (NSOM) can be used to optically and actively address remote nano objects such as quantum dots. Additionally we compare results obtained with near-field microcopy to those obtained with other optical far-field methods of analysis such as leakage radiation microscopy (LRM).

Effects of hydroxyurea on malaria, parasite growth and adhesion in experimental models

We recently raised concern over using hydroxyurea (HU) in the treatment of sickle cell disease in areas endemic for malaria, becauseit up-regulates the endothelial surface expression of ICAM-1, a major receptor for Plasmodium falciparum-infected erythrocytes in the brain. Using human in vitro models of cerebral malaria, we evaluated the interaction of HU with parasites and demonstrated that HU pretreatment increased the number of infected red blood cells adhering to the endothelium, but did not increase endothelial apoptosis. Moreover, using an experimental cerebral malaria model, HU pretreatment was found to prevent significantly mice from developing neurological syndrome by inhibiting parasite growth, opening potential therapeutic avenues.

Differential diagnosis of fetal hyperechogenic cystic kidneys unrelated to renal tract anomalies: A multicenter study

OBJECTIVES

To identify important factors in the differential diagnosis of renal cysts associated with hyperechogenic kidneys.

METHODS

This was a retrospective multicenter study. We identified 93 fetuses presenting between 1990 and 2002 with hyperechogenic kidneys and which had a diagnosis of nephropathy confirmed later. We analyzed retrospectively the prenatal ultrasound findings of those fetuses which were found sonographically to have renal cysts.

RESULTS

Of the 93 fetuses presenting with hyperechogenic kidneys and with a later diagnosis of nephropathy, there were 28 with autosomal dominant polycystic kidney disease (ADPKD), 31 with autosomal recessive polycystic kidney disease (ARPKD), 11 with Bardet-Biedl syndrome, nine with Meckel-Gruber syndrome, six with Ivemark II syndrome, one with Jarcho-Levin syndrome, one with Beemer syndrome and one with Meckel-like syndrome. One third of the fetuses (30/93) had renal cysts. Cystic characteristics (size, location, number) were not very useful for diagnosis; more useful was diagnosis of an associated malformation. Three (11%) of the fetuses with ADPKD had cysts, as did nine (29%) of those with ARPKD, three (27%) of those with Bardet-Biedl syndrome, all (100%) of those with Meckel-Gruber syndrome, three (50%) of those with Ivemark II syndrome, and each of the three cases with other syndromes (Jarcho-Levin, Beemer and Meckel-like syndromes). None of the cases with trisomy 13 had cysts. There were no associated malformations in the 12 cases with renal cysts and polycystic kidney disease; the other 18 cases with renal cysts were associated with malformations that were often specific, such as polydactyly in Bardet-Biedl and Beemer syndromes, occipital defect and Dandy-Walker malformation in Meckel-Gruber or Meckel-Gruber-like syndromes, and thoracic and/or vertebral abnormalities in Jarcho-Levin and Beemer syndromes.

CONCLUSION

Renal cysts associated with hyperechogenic kidneys are not rare. The clue to diagnosis is the demonstration of an associated malformation. If no malformation is found, the main diagnosis remains polycystic kidney disease, i.e. ARPKD or ADPKD.

A variant chronic B-cell lymphoma characterized by villous cells with novel immunophenotypic and cytogenetic profiles

The less common chronic B-cell lymphomas include hairy cell leukemia, hairy cell leukemia variant and splenic lymphoma with villous lymphocytes. These disease entities can sometimes cause a diagnostic dilemma; however, immunophenotypic markers have been identified as disease specific and scoring systems have been proposed to assist the process. This study reports a case of a chronic B-cell lymphoma with long cytoplasmic projections which does not fit into any of the published disease categories based upon a combination of clinical and morphological features and immunophenotyping. Furthermore, this case featured a combination of cytogenetic abnormalities not previously described in the published literature in association with a B-cell lymphoproliferative disorder.

Prenatal sonographic patterns in autosomal dominant polycystic kidney disease: a multicenter study

OBJECTIVE

To determine whether a specific prenatal sonographic pattern can be identified for autosomal dominant polycystic kidney disease (ADPKD) and if so whether it would be helpful in orienting complementary analysis, properly counseling parents and adapting pregnancy management.

METHODS

A retrospective multicenter study was conducted in four prenatal diagnostic centers. The records of fetuses with a prenatal ultrasound examination revealing abnormal kidneys and with a final diagnosis of ADPKD were analyzed. Ultrasound analysis included: amount of amniotic fluid, bladder size, renal length, presence or absence of renal cysts and size of renal pelves, and was focused on parenchyma echogenicity and status of corticomedullary differentiation. Postnatal follow-up was reviewed.

RESULTS

Of the 27 patients included in the study, 25 had hyperechogenic renal cortex and 20 had hypoechogenic medulla resulting in increased corticomedullary differentiation (CMD). In six cases, the medulla was hyperechogenic leading to absent or decreased CMD. One patient had normal cortical echogenicity and CMD. Renal cysts were present during the prenatal period in four patients (at 22 weeks in one case and after 30 weeks in three cases). In 12 patients, the cysts appeared after birth (within the first 6 months of postnatal life in 10 cases and by the age of 1 year in two cases). Elevated blood pressure was observed in only two cases and moderate chronic renal failure in one case.

CONCLUSION

We have described the sonographic presentation in fetuses with ADPKD: moderately enlarged hyperechogenic kidneys with increased CMD. Although not specific to ADPKD, these findings should prompt familial screening. Other prenatal sonographic features (absent or decreased CMD and cortical cysts) are less frequent.

Mesure pratique de l’irradiation en radiopédiatrie : utilisation du produit dose surface en fluorographie numérique et pour les radiographies pulmonaires néonatales

PURPOSE

Control of radiation dose in pediatric radiology requires knowledge of the reference levels for all examinations. These data are useful for daily quality assessment, but are not perfectly known for some radiographic examinations. The purpose of our study was to evaluate the dose related to voiding cystourethrograms (VCUG), upper GI (UGI) and intravenous urography (IVU). Neonatal chest radiographs in the intensive care unit were also evaluated.

MATERIAL AND METHODS

For examinations with contrast material (478VCUG, 220UGI, 80IVU), the children were divided in groups based on their weight, from 5 to 30 Kg. Measurements were performed using an ionization chamber and expressed with the dose-area product (DAP). For chest radiographs, a direct measurement of the entrance-skin dose was performed, with secondary calculation of the DAP.

RESULTS

For VCUGs, the DAP ranged between 42.89cGy.cm2 and 125.41cGy.cm2. The range was between 76.43 and 150.62cGy.cm2 for UGIs and between 49.06 and 83.33cGy.cm2 for IVUs. For neonate chest radiographs, DAP calculations were between 0.29 and 0.99cGy.cm2.

CONCLUSION

These values represent our reference doses. They allow continuous monitoring of our radiographic technical parameters and radiographic equipment and help to correct and improve them if necessary.

Hydroxyurea downregulates endothelin-1 gene expression and upregulates ICAM-1 gene expression in cultured human endothelial cells

The clinical efficacy of oral hydroxyurea (HU) in adults and children with sickle cell anemia (SCA) cannot solely be explained by its ability to enhance fetal hemoglobin (HbF) expression. Since increased adherence of sickle red blood cells to vascular endothelium is a possible contributing factor to vaso-occlusive crisis (VOC), we explored the effect of HU on human endothelial cell (EC) lines (TrHBMEC and EA-hy 926). We demonstrated that HU, in a dose-dependent and reversible manner, significantly decreased (up to three-fold) the release of endothelin-1 (ET-1), a vasoconstrictor peptide through downregulation (up to three-fold) of ET-1 gene expression. This finding is of therapeutic relevance as SCA patients exhibit elevated serum levels of ET-1 during episodes of VOC and levels correlate with disease severity. Unexpectedly, HU upregulated (up to three-fold) the expression of membrane-bound intercellular cell adhesion molecule 1 (mbICAM-1) and its soluble form (sICAM-1) with a parallel increase in ICAM-1 mRNA expression. Although ICAM-1 does not appear to be involved in the sickle cell adhesion to vascular endothelium, it may exacerbate vaso-occlusion by promoting leukocyte adhesion. The HU-induced increase in mbICAM-1 may appear inconsistent with the clinical benefits confered by HU. However, both the increase in sICAM-1- and HU-induced leukocyte reduction in patients, may counteract the potentially detrimental effect of elevated mbICAM-1 expression. Also HU reduces the expression of vascular cell adhesion molecule (VCAM-1) on EC. Since HU reduces the very late antigen 4-positive reticulocytes in SCA patients, a ligand for VCAM-1, HU-induced downregulation of VCAM-1 on EC will very likely decrease the reticulocyte-endothelium adhesion. Thus, HU, apart from inducing HbF expression in the red cell, also affects the expression profile of EC compartment.

Intra-rachidian disorders: two unusual cases of recurrent abdominal pain in children

Recurrent abdominal pain (RAP) is generally thought to be of psychological origin but organic aetiologies are increasingly being identified. The cases of two children with vertebral disorders revealed by recurrent abdominal pain are reported. A 14-y-old girl presented with RAP associated with scoliosis, due to a T8-T9 intra-dural extra-medullary tumour. A 7-y-old girl who suffered from nocturnal RAP located in the right iliac fossa for 1 y had decreased muscular strength, pyramidal signs, and a 10 degree Lassègue sign in the right lower limb, revealing a vascular malformation extending from T12 to L2.

CONCLUSION

Atypical pain and associated neurological signs or scoliosis must raise the possibility of intra-rachidian disorders. Magnetic resonance examination will then precisely state the location and nature of the pathological process, avoiding excessive delay in therapeutic management.

Abdominal cystic lymphangiomas in children: presurgical evaluation with imaging

Cystic lymphangiomas are benign vascular tumors which are most often seen in young children. They are considered to be congenital malformations stemming from sequestration of lymphatic tissue. The authors report 15 cases of abdominal location and detail the findings of imaging in the etiologic and topographic diagnosis of these lesions. The initial incidents were essentially the discovery of a palpable abdominal mass, and more rarely, an acute gastrointestinal complication. There was also one case of prenatal diagnosis. Plain films provide only indirect signs related to the displacement of neighboring organs. Ultrasonography permits the etiologic diagnosis by showing an often voluminous, septated cyst. The intra- or retroperitoneal location of the lesion is sometimes difficult to determine by sonography, in which case CT scanning is usually adequate. For abdominal locations, percutaneous sclerosis is not available, and surgical removal is the only treatment for this disorder. The topography of the lesion and the involvement of retroperitoneal structures is important to determine.

Prenatal diagnosis of schizencephaly by fetal magnetic resonance imaging

Schizencephaly is a neuronal migration anomaly characterized by gray matter lined clefts extending from the ventricle to the cortical surface leading to specific lesions, well demonstrated by imaging. The lips of the clefts can be fused or separated. Prognosis is related to the extend of the involved cortex. Both genetic and acquired factors can be responsible for this pathology. Three cases of antenatal diagnosed open schizencephaly are reported. Two cases are unilateral and one is bilateral. A cerebral anomaly has been detected in all cases by routine ultrasonography (US) revealing a ventricular dilatation with cortical associated abnormalities. Prenatal magnetic resonance imaging (MRI) permitted the diagnosis in the 3 cases. All cases had led to abortion because of the importance of the cortical defect. The aim of this report is to point out the importance of fetal MRI in the diagnosis of migration disorder and to discuss the medical implications. Indeed, MRI is better suited than US for the prenatal diagnosis of schizencephaly, being able to detect normal and abnormal brain cellular migration, especially with fast imaging (HASTE sequences). With its multiplanar imaging capability, MRI demonstrates the cleft extending from the pial surface to the ventricular ependyma and thus provides characteristic diagnosis of this disorder. Moreover, ventricular dilatation, a frequent anomaly detected by US should be completed with MRI in order to research a neuronal migration disorder.

Low-temperature near-field spectroscopy of CdTe quantum dots

A near-field optical microscope has been developed for operation at low temperature. This microscope is used to study the photoluminescence of CdTe-based quantum dots. Spectra collected upon approaching the optical tip into the near-field region of the sample reveal the evolution from a broad far-field luminescence band - that is typical for a large ensemble of dots - to a near-field structure made up of a few sharp peaks originating from individual dots. Experiments carried out in the excitation-collection mode through the optical tip allow study of the effect of an increase in excitation power on the near-field spectra. It is found that upon increasing the excitation by two orders of magnitude, a spatially resolved spectrum progressively transforms back into a broad 'far-field-like' spectrum. Photoluminescence images taken by scanning the sample under the tip are used to discriminate various contributions coming from individual dots.

MRI and clinical differences between optic pathway tumours in children with and without neurofibromatosis

The purpose of this study was to evaluate the value of MRI in studying optic pathway tumours associated with neurofibromatosis, and to look for potentially helpful criteria for the management of such lesions. This retrospective study included 14 children with neurofibromatosis type 1 (NF-1) as well as a lesion of the optic pathway. Clinical data and MRI findings were analysed with regard to location, structure and course of the tumours, and were compared with 13 optic pathway tumours in patients without NF-1. The median age of onset was 4.1 years. 11 patients with NF-1 were asymptomatic. In the NF-1 group, the optic nerves were involved in 10 cases without a cystic component at the time of diagnosis. In the non-NF-1 group, the tumour was located in the chiasma in 11 cases; 12 cases had a cystic component. 10 of the NF-1 group had no tumour progression over an average follow-up of 3.2 years without treatment. These findings suggest that optic astrocytomas in association with NF-1 are distinct lesions from isolated optic gliomas. In NF-1, most such tumours show only slight progression, and may correspond to perineural gliomatosis rather than a true pilocytic astrocytoma. Among NF-1 patients, initial MRI provides no prognostic criteria in children who subsequently show tumour progression. Nevertheless, MRI can be useful in establishing the diagnosis of NF-1 and can serve as a baseline study.

Schizencephaly: clinical and imaging features in 30 infantile cases

Schizencephaly is an uncommon structural disorder of cerebral cortical development, characterized by congenital clefts spanning the cerebral hemispheres from the pial surface to the lateral ventricles and lined by cortical gray matter. Either an antenatal environmental incident or a genetic origin could be responsible for this lesion which occurs between the third and fourth month of gestation. We report the clinical and cranial imaging features of 30 children, of whom 15 had unilateral and 15 had bilateral lesions. Their ages at the time of the first presentation ranged from 1 month to 10 years. They were thoroughly studied from clinical, epileptical, imaging and electroencephalographic (EEG) viewpoints. Five patients were investigated by cranial computed tomography (CT), eight by cranial magnetic resonance (MR) imaging, and 17 by both methods. The clinical features consisted of mild hemiparesis in 17 cases (57%), 12/17 were related to a unilateral phenotype (80% of all unilateral forms) and 5/17 to a bilateral phenotype. A tetraparesis was present in nine cases, all of which were due to a bilateral cleft. Bilateral forms were significantly associated with tetraparesis, whereas unilateral forms were associated with hemiparesis. Mental retardation was observed in 17 cases (57%), and was observed significantly more often in bilateral clefts (80%). When both hemispheres are involved, an absence of reorganization of the brain function between the two hemispheres leads to severe mental deficits, in addition to the cerebral anomaly itself. Eleven patients had seizures (seven from unilateral and three from bilateral forms). The degree of malformation was not related to the severity of epilepsy. Migration disorders, such as dysplasia or heterotopia, were observed in 30% of cases and are also important etiopathogenetic factors. The septum pellucidum was absent in 13 cases (43%), with septo-optical dysplasia in two cases. Corpus callosum dysgenesis was noted in 30% of cases. Four cases of mega cisterna magna were noted. Although familial cases and environmental factors have been previously reported, schizencephaly appears to be, in the majority of cases, sporadic.

Capillary haemangioma of the greater omentum in a 5-month-old female infant: a case report

Capillary haemangiomas are frequent benign tumours in infancy. The authors report a case of capillary haemangioma of the greater omentum, discovered in a child of 5 months of age and studied with US, CT and MRI. The localization of such a lesion in the greater omentum is exceptional. Abdominal US revealed a heterogeneous, multinodular intraperitoneal mass. Doppler study demonstrated hypervascularity of the lesion. CT localized the mass to the greater omentum. The mass was hypodense on the unenhanced scan and enhanced massively after injection. The infant suffered a reaction to contrast medium during the CT. MRI demonstrated a mass which was hypointense on T1-weighted images and hyperintense on T2-weighted images. Laparotomy confirmed the location of the mass within the greater omentum and allowed resection of the tumour.

Acute basophilic leukemia presenting with abnormal liver function tests and the absence of blast cells in the peripheral blood

Acute basophilic leukemia is an uncommon form of acute leukemia, rarely occurring as a de novo disease. We describe a case of de novo acute basophilic leukemia occurring in a 47-year-old man who presented with abnormal liver function tests in the absence of leukemic infiltration of the liver. We postulate that this presentation occurred as a consequence of pathophysiological features of the malignant basophilic blast cells.

[Concomitant chemoradiotherapy and preoperative radiotherapy in exocrine pancreatic adenocarcinoma]

The prognosis of pancreatic adenocarcinoma remains poor, with a 5-year survival rate lower than 5%. Resection, the gold standard treatment, can be performed in less than 10% of patients. Following surgery, the median survival is 12 months. Concomitant chemoradiation, as an adjuvant treatment could be superior to surgery alone, in terms of survival; controlled trials are currently performed. Neoadjuvant chemoradiation is a new approach, potentially able to increase survival and resection rate. Finally, current data regarding intraoperative irradiation are exposed.

Abdominal ultrasound findings in children with hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis, a variant of histiocytosis, is characterized by an uncontrolled activation of the cellular immune system, including hepatic mononuclear phagocytic cells. Abdominal ultrasound findings in children are evaluated in this disease. We present six pediatric cases, two with familial and four with sporadic hemophagocytic lymphohistiocytosis, examined by abdominal sonography. Three signs were frequently observed: thickening of the gallbladder wall (all cases), increased periportal echogenicity (four cases), and enlarged lymph nodes in the porta hepatis (four cases). Hepatomegaly, splenomegaly, and ascitic fluid may also be found. These imaging findings are not specific and may be seen in viral hepatitis. However, once hepatitis is excluded, they may suggest the diagnosis of hemophagocytic lymphohistiocytosis in a critically ill child. A bone smear must be done to establish the diagnosis.

Localised proton magnetic resonance spectroscopy of the brain after perinatal hypoxia: a preliminary report

OBJECTIVES

Perinatal hypoxic ischaemic injury is a significant cause of neurodevelopmental impairment. The aim of this study was to evaluate localised proton magnetic resonance spectroscopy (1H-MRS) after birth asphyxia.

MATERIALS AND METHODS

Thirty newborn infants suspected of having perinatal asphyxia (Apgar score < 3) were studied. The mean gestational age was 37 weeks, mean age at the MR examination was 18 days and mean weight was 2.9 kg. A 1.5-T unit was used for imaging and spectroscopy. None of the babies had mechanically assisted ventilation. No sedation was used. Axial T1-weighted and T2-weighted images were obtained. 1H-MRS was recorded in a single voxel, localised in white matter, using a STEAM sequence.

RESULTS

Image quality was good in 25 of 30 babies. 1H-MRS was performed in 19 of 30 subjects, with adequate quality in 16. Choline, creatine/phosphocreatine and N-acetylaspartate peaks and peak-area ratios were analysed. Lactate was detected in four infants. The N-acetylaspartate/choline ratio was lower in infants with an impaired neurological outcome, but the difference was not statistically significant.

CONCLUSIONS

This study suggests that 1H-MRS may be useful for assessing cerebral metabolism in the neonate. A raised lactate level and decreased N-acetylaspartate/choline ratio may be predictive of a poor outcome. However, in our experience this method is limited by the difficulty in performing the examination during the first hours after birth in critically ill babies, the problems related to use of a monovoxel sequence, the dispersion of the ratios and the lack of determination of the absolute concentration of the metabolites.

[Diagnostic prenatal ultrasonography of malformations of the fetal anterior abdominal wall]

Abdominal wall defects include a broad spectrum of structural malformations with variable severity and prognosis. The purpose of prenatal ultrasound examination is to correctly diagnose and classify these malformations according to their localization (particularly their relation to the umbilical cord insertion), their contents, their size and associated malformations or karyotypic abnormalities. Based on this examination, two groups can be distinguished: gastroschisis or omphalocele (when the latter is isolated, in particular without karyotypic abnormalities) which can be surgically corrected at birth, and for which predictive criteria of outcome must be evaluated (vitality of herniated bowel, size and contents of omphalocele); severe malformations (ectopia cordis, cloacal exstrophy, Beckwith-Wiedemann syndrome, short umbilical cord, amniotic band syndrome) for which pregnancy termination could be proposed.

Breast metastases in adolescent girls: US findings

We report five adolescent girls with secondary breast tumours. All were imaged by US and the imaging findings have been analysed. Four girls had rhabdomyosarcoma as the primary malignant disease and one had leukaemia. US features were variable, but most of the cases showed heterogeneous nodules which were quite different from the usual benign lesions (fibroadenoma, abscess, cyst) encountered at this age. The metastases produced a variety of echo characteristics: masses with well-defined margins, hyperechoic foci and sonolucent or hypoechoic nodules with posterior attenuation or lacking posterior enhancement. One lesion was round and heterogeneous with a hyperechoic centre. These US findings in an adolescent girl suggest the need for fine-needle aspiration. Mammograms, when performed, never revealed microcalcifications and were quite difficult to analyse at this age, due to the dense glandular breast tissue.

[Temporal lobe epilepsy and ganglioglioma in children. Clinical aspects, imagery and neuropathology; nosological discussion of six cases]

BACKGROUND

Gangliogliomas belong to debated nosological entity. They are classified as neuronal or neuroglial tumors.

PATIENTS AND METHODS

Six children aged from 4 months to 15 years (mean age: 4 years and 6 months) were initially seen for partial seizures resistant to treatment. Tumoral resection was performed in all six. Diagnosis was made from immunohistological study of the tumor.

DISCUSSION

Gangliogliomas are non-malignant, with a good prognosis, even if inaugural clinical manifestations are severe. Neuroradiological diagnosis with astrocytomas and cortical dysplasia is not easy, and pathological distinction from cortical dysplasia is difficult.

CONCLUSION

The immunohistochemical confirmation of diagnosis permits a logical therapeutic attitude: complete resection of tumor is followed by an excellent outcome.

MDR1 and MRP expression in chronic B-cell lymphoproliferative disorders

The role of the MDR1 and MRP genes in drug resistance in patients with chronic lymphocytic leukaemia (CLL)/non-Hodgkin's lymphoma (NHL) is unclear. We hypothesized that any relationship between levels of expression and exposure to P-glycoprotein (P-gp) transportable drugs may become evident by using a measure of gene expression that combined the number of positive cells and the degree of positivity. 68 CLL/NHL patients were analysed using flow cytometry with MDR1 and MRP specific antibodies and were divided into subgroups, untreated (n = 31). treated with non P-gp transportable drugs (n = 26), those treated with low total doses of P-gp transportable drugs (n = 6) and patients treated with high total doses of P-gp transportable drugs (n = 5). The group exposed to high doses of P-gp transportable drugs had higher levels of MDR1 expression when compared to all other groups (P<0.05, ANOVA). A positive correlation between the level of MDR1 expression and the cumulative dose of P-gp transportable drugs was demonstrated (P=0.02). MRP expression was higher in those patients exposed to high doses of P-gp transportable drugs when compared to all other groups (P<0.05. ANOVA), although only a trend towards a linear dose correlation effect could be established (P=0.08). We concluded that MDR1 and MRP are involved in drug resistance but only in patients treated with P-gp transportable drugs.

Granulomatous hepatitis in pasteurella multocida infection

Numerous diseases can lead to multilocular lesions of the liver. The authors report a rare pediatric case of hepatic granulomas due to Pasteurella multocida: a 7-year-old girl with chronic fever was investigated by sonography and CT scan, demonstrating mesenteric lymph node enlargement and numerous small hepatic lesions. After surgical biopsy, histopathology of the liver specimens showed pyogenic granuloma, with serologic testing positive for Pasteurella multocida. Treatment with a tetracycline and corticosteroids was successful. Pasteurella multocida infection, despite its habitual benign course, should be suspected among differential diagnoses of lymphogranulomatous affections with hepatic involvement. No case of liver and lymph node foci in a child has been previously described.

Gastroschisis: are prenatal ultrasonographic findings useful for assessing the prognosis?

OBJECTIVE

The objective of this study was to assess various prenatal patterns in correlation with survival and the occurrence of complications of antenatally recognized gastroschisis (G).

MATERIALS AND METHODS

We retrospectively studied 34 cases of G. Mortality and morbidity in the postnatal period were assessed and correlated with the prenatal presence or absence of: (1) bowel and/or stomach dilatation, (2) thickening and/or hyperechogenicity of the intestinal wall, (3) meconium peritonitis (in the abdomen) before 20 weeks of gestation, (4) asymmetrical bowel dilatation, and (5) associated malformations. Morbidity took into account the length of hospitalization and the number of surgical procedures.

RESULTS

The overall survival rate was 94%. Neither bowel nor stomach dilatation was significantly correlated with mortality. However, evidence of intestinal dilatation greater than 17 mm had a positive predictive value of 67% for atresia, with a negative predictive value of 86%. Thickening and/or hyperechogenicity of the bowel wall were not significantly associated with mortality. Meconium peritonitis before 20 weeks and asymmetrical bowel dilatation were not statistically significant because of the small sample size. Twelve patients (35.3%) had postnatal complications, with a mean hospital stay of 127 days. Outcome was not modified by the mode of delivery. Associated extradigestive anomalies were present in 20.6% of cases. Chromosomal anomalies were not seen.

CONCLUSION

The prognosis of prenatally detected G is excellent despite the frequency of small bowel atresia (67%) in the group with postnatal complications. Meconium peritonitis before 20 weeks of gestation and/ or asymmetrical bowel dilatation also appear to be indicators of atresia (2/4, 50%) or high morbidity (3/4, 75%).

Infantile myofibromatosis

An unusual case of infantile myofibromatosis with foci of calcifications was presented, with atypical age of onset and location. The radiological features of this tumor are not always evocative, and histological examination is necessary for diagnosis.

[Propafenone and verapamil poisoning. Report of 2 clinical cases]

We described the self-poisoning of two young adolescents who took improper doses of two major cardiovascular drugs: propafenone and verapamil. The young girls developed markedly different clinical patterns: ECG abnormalities without clinical consequences were found in one case progressively ingravescent ECG abnormalities leading to cardiac arrest in the other. These differences are probably due to varying doses taken and metabolic states. Conventional detoxication and resuscitation techniques proved successful in both cases.

Identification of Salmonella somatic and flagellar antigens by modified serological methods

This report describes two modified methods for the identification of Salmonella somatic (O) and flagellar (H) antigens. Over a period of 2 years, both modified methods were found to be approximately three times less labor intensive than the standard methods while requiring no more technical skill. The modified methods were as accurate as the standard methods in identifying the O and H antigens of 350 Salmonella isolates. Furthermore, 43 O antisera reacted exclusively with organisms possessing homologous O antigens when the modified and two standard methods were used. At the antiserum dilutions used for H antigen identification, H antisera did not react with O antigens or heterologous H antigens by either the modified or the standard method. Compared with the standard method for H antigen identification, the modified method was approximately 20 times more economical with respect to antisera and usually generated a 1.5- to 4-fold higher titer. Since the antisera stored for use in the modified method for H antigen identification were usually 100-fold more dilute than the antisera stored for the standard method, an antibody-stabilizing buffer was incorporated in the diluted antisera, allowing these reagents to be used for at least 9 to 16 months.