MR imaging of the brain in pediatric patients: diagnostic value of HASTE sequences

OBJECTIVE: The objective of this study was to determine the diagnostic value of half-Fourier single-shot turbo spin-echo (HASTE) sequences in MR imaging of the brain in pediatric patients. SUBJECTS AND METHODS: HASTE sequences were performed in 80 infants and children. Two radiologists who were unaware of the patients' medical histories independently reviewed the images for the presence of nine findings: defects of the parenchyma, hypoplasia or agenesis of the corpus callosum, edema, signs of increased intracranial pressure, myelination disorders, migration disorders, malformations, tumors, and widening of spaces of the cerebrospinal fluid. A conventional MR imaging examination that served as the reference examination was evaluated by the same two radiologists in a final consensus interpretation. The findings detected on the HASTE images were compared with the findings seen on the conventional MR images. The sensitivity and specificity of HASTE sequences were calculated, and Cohen's kappa statistic was used to determine interobserver agreement. RESULTS: Both radiologists correctly diagnosed all 20 defects of the parenchyma that were present in the patients. Radiologist 1 correctly identified 20 and radiologist 2 correctly identified 21 of the 22 patients with hypoplasia or agenesis of the corpus callosum. Both radiologists correctly diagnosed edema in eight of the nine patients in whom edema was present, and both correctly identified signs of increased intracranial pressure in eight of the nine children who had this condition. Radiologist 1 correctly diagnosed seven and radiologist 2 correctly identified nine of the 11 cases of myelination disorders. Both radiologists correctly diagnosed six of the 14 cases with migration disorders. All 13 brain malformations present in the patients were correctly identified by both reviewers. Both radiologists correctly identified all 11 patients with tumors, and both correctly identified all 35 patients with widening of spaces of the cerebrospinal fluid. CONCLUSION: HASTE images are highly sensitive for excluding the presence of brain tumor, hydrocephalus, or malformations of the brain. HASTE images are not reliable for evaluating patients with suspected myelination disorders or migration disorders.     

Epidermal growth factor-mediated activation of the map kinase cascade results in altered expression and function of ABCG2 (BCRP).

Epidermal growth factor (EGF) is a multifunctional growth factor known to play a major role in proliferation and differentiation processes. EGF-induced differentiation is a prerequisite for function of various cell types, among them cytotrophoblasts, a functionally important cellular fraction in human placenta. Stimulation of cytotrophoblasts with EGF results in formation of a multinuclear syncytium representing the feto-maternal interface, which protects the fetus against exogenous substances. It is well established that part of this protection system is based on ATP-binding cassette (ABC) transporters such as ABCG2 (breast cancer resistance protein, BCRP). However, little is known about regulation of transport proteins in the framework of EGF-mediated cellular differentiation. In the present work we show a significant increase of ABCG2 expression by EGF in cytotrophoblasts, BeWo, and MCF-7 cells on both mRNA and protein levels. This increase resulted in decreased sensitivity to the ABCG2 substrates mitoxantrone and topotecan. In each cell type, EGF increases expression of ABCG2 by activation of mitogen-activated protein kinase cascade via phosphorylation of extracellular regulated kinase (ERK)1/2 and c-jun NH-terminal kinase/stress-activated protein kinase (JNK/SAPK). Consequently, the increase of ABCG2 by EGF was abolished by pretreatment of cells with the tyrosine kinase inhibitor 4-(3-chloroanillino)-6,7-dimethoxyquinazoline (AG1478) or the mitogen-activated protein kinase kinase inhibitor 2'-amino-3'methoxyflavone (PD 98059), thereby reestablishing sensitivity toward mitoxantrone. Moreover, analysis of ABCG2 expression during placental development revealed a significant increase in preterm versus term placenta. Taken together, our data show regulation of ABCG2 expression by EGF. In view of EGF signal transduction as a target for drugs (e.g., gefitinib), which are in turn substrates and/or inhibitors of ABCG2, this regulation has therapeutic consequences.     

血清SOD、MDA、NO与突发性聋的相关研究

目的：通过对突发性聋病人血中一氧化氮（NO）、丙二醛（MDA）、超氧化物歧化酶（SOD）含量的检洲，探讨突聋与血氧自由基和自由基的清除剂SOD之间的关系。方法：采用硝酸还原酶法测定了30例突聋病人血中NO含量，并以25例同期体检正常的健康人为对照组；同时还用硫代巴比妥酸比色法测定MDA含量，用黄嘌呤氧化酶法测定SOD含量。砖呆；应用金纳多、能量合剂、克林臭（即马来酸桂哌齐特，钙通道阻滞药）联合静脉输入，突聋各组的听力均有不同程度提高，有效率在78．57％以上。治疗后同对照组相比，血清NO、MDA水平明显低于患病之初，而SOD活性明显高于治疗之前，P〈0．01。结论；检测突聋病人血中N0、MDA、SOD的含量，能帮助我们探讨突聋的发病机理，估计预后。血氧自由基的升高可能是突聋发病因素之一，而SOD的含量可以帮助我们估计预后。     

Primary osteosarcoma of the skull

Primary osteogenic sarcoma of the skull is an exceedingly rare condition. An adult male patient is described, who had a painless swelling in the right forehead that had rapidly enlarged in the previous 6 months. Radiological investigations showed a large destructive mass lesion involving the right side of the frontal bone with extension into the frontal sinus, causing marked extradural compression of brain parenchyma. Histopathological examination confirmed the lesion to be primary osteogenic sarcoma.     

维甲酸和联合应用神经营养因子对新生大鼠神经干细胞分化的影响

目的研究全反式维甲酸（ATRA）及联合应用神经营养因子（BDNF，GDNF）对体外培养的神经干细胞（NSCs）分化的影响。方法取新生SD大鼠的前脑室下带（SVZ）区，按NSCs的常规培养方法分离、培养。用免疫细胞化学法鉴定巢蛋白（nestin）、微管相关蛋白-2（MAP-2）、胶质原纤维酸性蛋白（GFAP）的表达，以此来观察ATRA、BDNF、GDNF单独或联合应用对次代神经球细胞分化的作用。结果原代及次代神经球均显示nestin阳性，并可分化为MAP-2阳性神经元样细胞及GFAP阳性胶质细胞样细胞。1μmol／LATRA可促进NSCs分化为MAP-2阳性细胞的比例达（29．14±5．00）％，显著高于对照组的（7．19±1．21）％，差异有高度统计学意义（P〈0．001）。ATRA联合应用10ng／ml的BDNF或GDNF，与单独使用ATRA比较，并不显著提高NSCs分化为MAP-2阳性细胞的比例。结论ATRA可促进神经干细胞向神经元方向分化，ATRA联合应用BDNF或GDNF无明显的协同作用。     

Enzyme-linked immunosorbent assay to assess respiratory syncytial virus concentration and correlate results with inflammatory mediators in tracheal secretions

OBJECTIVE: We developed an enzyme-linked immunosorbent assay (ELISA) for the quantitation of respiratory syncytial virus (RSV) in respiratory secretions in intubated patients infected with RSV. METHODS: We compared the quantitative ELISA and a standardized plaque assay in intubated children <2 years of age who were mechanically ventilated for severe RSV disease and enrolled in a randomized double blind placebo-controlled treatment trial of a monoclonal antibody to the F protein of RSV (palivizumab; Synagis). We also examined the relationship between the concentrations of virus as measured by ELISA and of three inflammatory indices in respiratory secretions (white blood cell count, myeloperoxidase and eosinophilic cationic protein). RESULTS: Quantitative ELISA and plaque assay were highly correlated for both tracheal aspirates (r = 0.67, P = 0.001) and nasal wash specimens (r = 0.75, P = 0.001). Treatment with palivizumab significantly neutralized RSV in tracheal aspirates as measured by plaque assay. In contrast quantitation of RSV by ELISA was not affected by palivizumab treatment. This finding is consistent with results that were obtained in preliminary studies of RSV-containing media treated with monoclonal antibody, where we found that the ELISA measured virus whether antibody-bound or not. The inflammatory indices were not correlated with RSV concentration measured by ELISA or plaque assay. CONCLUSIONS: We conclude that this quantitative ELISA is a potentially useful tool for measurement of RSV concentration in respiratory secretions that may help elucidate the pathophysiology of acute RSV infection. Specific antiviral strategies for the treatment of RSV disease could be evaluated by this method.     

Relations between age, metabolic control, disease adjustment and psychological aspects in insulin-dependent diabetes mellitus

The relations between age, metabolic control, disease adjustment, and psychological factors in boys and girls with recently diagnosed insulin-dependent diabetes mellitus (IDDM) were studied. Older girls had significant higher postremission glycosylated haemoglobin A (Hb A_lc) levels ( p = 0.008). Girls with more hospitalizations had a lower developmental level ( p = 0.05), and had significantly more problems in the behavioural rating ( p = 0.05). Boys with more hospitalizations had a more external locus of control ( p = 0.01), more difficulties with disease adjustment, more emotional problems, and were also clinically assessed as having more behavioural problems. Boys showing more difficulties in psychological adjustment to the disease also had higher postremission Hb A_1clevels ( p = 0.02). Although Swedish children with IDDM of short disease duration do not differ from healthy children in important psychological aspects, older girls and a small group of problematic younger boys are at risk of developing metabolic imbalance after a short disease duration.     

Metabolic effects of growth hormone treatment: an early predictor of growth response?

Fourteen children receiving one year of recombinant human growth hormone (rhGH) treatment underwent measurement of serial changes in body composition (measured by skinfold thickness, bioelectrical impedance, and H2(18)O dilution), resting energy expenditure (REE, estimated by ventilated hood indirect calorimetry), and total free living daily energy expenditure (TEE, measured by the doubly labelled water technique). Mean height velocity increased from 4.9 to 8.6 cm/year after six months of treatment. Fat free mass (FFM) increased more during the first six weeks (24.4 g/day) than from six to 26 weeks of treatment (6.8 g/day); fat mass decreased by 7.2 g/day and 1.1 g/day respectively. The six week increase in REE (kJ/day) was maintained after six months of treatment, though expressed per kilogram FFM (kJ/kgFFM/day), returned to pretreatment values by three months. Height velocity increases at six months correlated with six week changes in fat mass measured by skinfold thickness and REE, though use of this relationship to predict growth response in individuals is limited by the wide 95% prediction intervals. No significant changes in growth, body composition, or energy expenditure were observed between six and 12 months of treatment, in either patients who had initially responded well to treatment or those who were poor initial responders to treatment and who had their dose of rhGH doubled after six months.