Immunocytochemical demonstration of interphotoreceptor retinoid-binding protein in cerebellar medulloblastoma

Summary Previously, immunoreactive rod-opsin and S-antigen (arrestin), two highly characteristic markers of retinal photoreceptors and pinealocytes, were shown to be present in certain medulloblastoma cells. It, thus, has been suggested that such cells differentiate along the photoreceptor lineage. This is corroborated in the present immunocytochemical investigation using antibodies against another photoreceptor-cell marker, the interphotoreceptor retinoid-binding protein (IRBP). As shown in preparations of human retina and pineal organ, IRBP can be successfully demonstrated in formalinfixed and paraffin-embedded tissue: the IRBP immunoreaction is located to the outer and inner segments of retinal photoreceptor cells and to perikarya of certain pinealocytes. Examination of formalin-fixed, paraffinembedded biopsy specimens of 66 cerebellar medulloblastomas revealed varying numbers of IRBP-immunoreactive tumor cells in 19 cases that were formerly shown to contain rod-opsin and S-antigen immunoreaction. IRBP-immunoreactive tumor cells were also found in a retinoblastoma and a pineocytoma, but not in neuroblastoma, ganglioneuroblastoma, glioblastoma, oligodendroglioma and astrocytoma. The results indicate: (1) cerebellar medulloblastomas are heterogeneous in their differentiation potential; (2) one type of medulloblastoma displays photoreceptor characteristics; (3) this type appears to be closely related to retinoblastoma and pineal cell tumors; and (4) all three types of tumors may display additional common features to be explored in future studies.     

Glial fibrillary acidic protein in medulloblastoma

Summary Twenty-four cases of classical medulloblastoma and one case of desmoplastic medulloblastoma were examined for glial fibrillary acidic protein (GFAP) using the immunoperoxidase method to assess astrocytic differentiation. In 16 cases of classical medullablastoma GFAP-positive cells were present in variable numbers.These cells were classified as three different types according to size and shape. The type 1 cell was morphologically identical to the ordinary tumor cell, with a hyperchromatic nucleus and a scanty cytoplasm. The type 2 cell had a fairly rich cytoplasm with short cytoplasmic processes. The type 3 cell was characterized by a relatively large nucleus with sparse chromatin and well-developed cytoplasmic processes, and was considered a reactive astrocyte. The type 1 and some of the type 2 cells seemed to be neoplastic, displaying astrocytic differentiation. The remaining type 2 cells may have been reactive astrocytes.In one case of desmoplastic medulloblastoma, the majority of GFAP-positive cells were arranged in islands, and had delicate fibrillated processes. GFAP-positive cells were also observed outside these islands, though they were less numerous. Most of them were regarded as type 3 cells, but some were type 2. This may be interpreted as meaning that the glial character of the tumor was expressed more within than outside these islands.     

Caffeic acid phenethyl ester preferentially enhanced radiosensitizing and increased oxidative stress in medulloblastoma cell line

OBJECTIVES: Caffeic acid phenethyl ester (CAPE), an active component of propolis, was recently reported to have radiosensitizing effects on medulloblastoma (MB) cells. However, the mechanisms of radiosensitivity involved in medulloblastoma cells are still unclear. The specific aim of this study was to investigate the role of CAPE-induced oxidative stress to influence of radiosensitivity and anti-proliferative effects in medulloblastoma cells. MATERIALS AND METHODS: Medulloblastoma (Daoy) cells were treated with CAPE in different concentrations and assessed for cell viability. The following were also evaluated: migratory ability, reduced glutathione (GSH) level, reactive oxygen species (ROS) level, nuclear factor-kappaB (NF-kappaB) activity, and apoptosis in CAPE alone, radiation alone, or radiation combined with CAPE in Daoy cells. RESULTS: The results indicated that CAPE inhibited the growth of Daoy cells. CAPE treatment in Daoy cells could effectively decrease glutathione reductase and significantly increase glutathione peroxidase. Radiation-activated NF-kappaB was reversed by CAPE pretreatment. Finally, the result of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay showed that CAPE treatment can enhance radiation-induced apoptosis in Daoy cells. CONCLUSIONS: Our study demonstrated the anti-proliferative and radiosensitizing effects of CAPE on MB cells, which may be achievable through depleting GSH, increased ROS activity, and inhibiting NF-kappaB activity.     

Childhood leukemia survivors exhibit deficiencies in sensory and cognitive processes,as reflected by event-related brain potentials after completion of curative chemotherapy: A preliminary investigation

Objective: The purpose of this study was to characterize post-chemotherapy sensory, memory, and attention abilities in childhood survivors of acute lymphoblastic leukemia (ALL) to better understand how treatment affects cognitive functioning.

Methods: Eight ALL survivors and eight age-matched, healthy children between the ages of 5-11 years participated in the study. Among the ALL survivors, a median of 63 days (range 22-267 days) elapsed between completion of chemotherapy and this assessment. Sounds were presented in an oddball paradigm while recording the electroencephalogram in separate conditions of passive listening and active task performance. To assess different domains of cognition, we measured event-related brain potentials (ERPs) reflecting sensory processing (P1 component), working memory (mismatch negativity [MMN] component), attentional orienting (P3a), and target detection (P3b component) in response to the sounds. We also measured sound discrimination and response speed performance.

Results: Relative to control subjects, ALL survivors had poorer performance on auditory tasks, as well as decreased amplitude of the P1, MMN, P3a, and P3b components. ALL survivors also did not exhibit the amplitude gain typically observed in the sensory P1 component when attending to the sound input compared to when passively listening. Conclusions: Atypical responses were observed in brain processes associated with sensory discrimination, auditory working memory, and attentional control in pediatric ALL survivors indicating deficiencies in all cognitive domains compared to age-matched controls.

Significance: ERPs differentiated aspects of cognitive functioning, which may provide a useful tool for assessing recovery and risk of post-chemotherapy cognitive deficiencies in young children. The decreased MMN amplitude in ALL survivors may indicate (N-methyl D-aspartate) NMDA dysfunction induced by methotrexate, and thus provides a potential therapeutic target for chemotherapy-associated cognitive impairments.     

Impact of intracranial pressure and cerebral perfusion pressure on severe disability and mortality after head injury

Objective  To investigate the relationships between intracranial pressure (ICP), cerebral perfusion pressure (CPP), and outcome after traumatic brain injury. Material and Methods  A retrospective analysis of prospectively recorded data from 429 patients after head injury requiring intensive treatment on the Neuroscience Intensive Annex and the Neuro Critical Care Unit, Cambridge, UK. ICP, CPP, and arterial blood pressure (ABP) were continuously recorded. Mean values of pressures were compared to outcome assessed at 6 months after injury (using the Glasgow Outcome Scale). Results  The mortality rate was greater in those having mean ICP greater than 20 mmHg (17% below versus 47% above; p<0.00001). The mortality rate was dramatically increased for CPP below 55 mmHg (81% below versus 23% above; p<0.0001). For values of CPP greater than 95 mmHg, favorable outcome was less frequent (50% below versus 28% above; p<0.033). The rate of severe disability showed the tendency to increase with CPP (r=0.87; p=0.02), suggesting that a higher CPP does not help in achieving favorable outcomes. ICP was greater in those who died in comparison to those who survived (27±19 mmHg versus 16±6 mmHg; p<0.10–7), and CPP was lower (68±21 versus 76±10 mmHg; p<0.0002). There was no difference between mean ICP and CPP in good/moderate and severe disability outcome groups. Conclusion  High ICP is strongly associated with fatal outcome. Excessive CPP seems to reduce the probability of achieving a favorable outcome following head trauma.     

应用荧光原位杂交技术动态监测化疗与干细胞移植后白血病患者的染色体变化

背景：荧光原位杂交技术被广泛应用于白血病异常基因的检测中,但对于应用此项技术比较化疗与移植后疗效的研究尚未见大量报道。 目的：评价荧光原位杂交技术对化疗与移植后白血病患者的监测效果。 方法：新疆医科大学第一附属医院血液二科2009-10/2010-10收治的白血病患者44例,收集标本85份。按照各自采取的主要治疗方案,分为治疗前组,普通化疗组,特殊药物治疗组和造血干细胞移植组。特殊药物治疗组包括全反式维甲酸治疗和甲磺酸伊马替尼治疗患者。 结果与结论：荧光原位杂交技术在诊断与监测白血病微小残留病灶方面较染色体核型分析更为精确;荧光原位杂交结果显示特殊药物治疗组与造血干细胞移植组阳性细胞百分数均明显低于治疗前组和普通化疗组(P < 0.01),但特殊药物治疗组与造血干细胞移植组间差异无显著性意义(P > 0.05);急性移植物抗宿主病发生与移植后1个月荧光原位杂交结果不具有相关性(P > 0.05);移植后1个月、1~6个月、6个月以上荧光原位杂交检测结果差异无显著性意义(P > 0.05)。提示荧光原位杂交技术可以准确而有效的动态检测移植后患者的染色体变化情况,评价患者疾病发展趋势。     

Stabilization of TMB Reaction Product for electron microscopic retrograde and anterograde fiber tracing

Use of the highly sensitive tetramethylbenzidine (TMB) method of horseradish peroxidase histochemistry for electron microscopy has been limited by the solubility of the reaction product in aqueous and alcoholic solutions. We have found that following the TMB reaction with a diaminobenzidine-cobalt (DAB-Co) step causes the TMB crystals to become coated with DAB-Co. The resultant reaction complex is insoluble, and easily localized using electron microscopy. By systematically varying the pH at which the TMB reaction is run, the size and shape of the reaction complex can be controlled. The pH 4.0 reaction complex was the most suitable for electron microscopic identification of labeled structures less than 1.0 micron in diameter (e.g., axon terminals).     

Targeting electroencephalography for alcohol dependence: A narrative review

Background

Electroencephalography (EEG)-based electrophysiological techniques have made progress in diagnosing and treating alcohol dependence in recent years.

Aims

The article reviews the latest literature in this field.

Materials and methods

Alcohol dependence, which is common and prone to relapsing, poses a serious threat to individuals, families, and society. At present, the objective detection methods for alcohol dependence in clinic are not enough. As electrophysiological techniques developed in psychiatry, some researches on EEG-based monitoring methods are of great significance in the diagnosis and treatment of alcohol dependence.

Discussion

As electrophysiological techniques developed in psychiatry, some researches on EEG-based monitoring methods such as resting electroencephalography (REEG), event-related potentials (ERP), event-related oscillations (ERO), and polysomnography (PSG), was reported.

Conclusion

In this paper, the status of electrophysiological researches on EEG in alcoholics are reviewed in detail.     

Genomic organization and mutation analysis of three candidate genes for hereditary neuralgic amyotrophy

Hereditary neuralgic amyotrophy (HNA) is an autosomal-dominant inherited recurrent focal neuropathy affecting mainly the brachial plexus. In this study we report the genomic structure and mutation analysis of three candidate genes: sphingosine kinase 1 (SPHK1); tissue inhibitor of metalloproteinase 2 (TIMP2); and cytoglobin (CYGB). We did not find any disease-associated mutations, indicating that HNA is not caused by point mutations in these genes. However, we identified several sequencing errors in the cDNA of SPHK1 as well as seven novel single-nucleotide polymorphisms.     

Adenosine deaminase activity in cerebrospinal fluid and serum for the diagnosis of tuberculous meningitis

Objective

To evaluate the usefulness of serum and CSF adenosine deaminase (ADA) activity for the diagnosis of tuberculous meningitis (TBM) from other meningitis.

Methods

We studied CSF and serum ADA activity for 83 cases of TBM, 148 of bacterial meningitis (BM), and 262 of viral or aseptic meningitis.

Results

The mean ADA activities (IU/L) in CSF and serum were higher in TBM (11.80 ± 2.50, 30.28 ± 7.30) than in other types of meningitis (8.52 ± 3.60, 17.90 ± 9.20 in BM; 5.26 ± 1.90, 8.56 ± 5.9 in viral or aseptic meningitis). When we accepted a serum ADA activity cut-off value of 15 IU/L for the differential diagnosis of TBM and non-TBM with ROC analysis, the sensitivity was 84% and specificity was 82%. Combining CSF (≥10) and serum (≥15) ADA activity significantly increased overall specificity from 92% to 97% for the diagnosis of TBM.

Conclusions

The determination of CSF and serum ADA activity is a simple and reliable test for differentiating TBM from other types of meningitis.     

Extracranial to intracranial bypass for the treatment of cerebral aneurysms in the pediatric population

Cerebral aneurysms are rare in the pediatric population, making a definitive treatment algorithm difficult. Microsurgical clipping is the first choice for treatment but is not always feasible, while high recurrence rates and radiation exposure make endovascular options less favorable. Extracranial-intracranial (EC-IC) bypass, though not commonly performed in the pediatric aneurysm population, has been reported in a small number of studies to be both safe and effective for the management of cerebral aneurysms. The authors present the case of a child with a distal middle cerebral artery (MCA) aneurysm in eloquent territory, successfully treated with a superficial temporal artery (STA) to MCA bypass and trapping. A review of the current literature on pediatric EC-IC bypass in the treatment of intracranial aneurysms is presented.     

A new clinically relevant model for intracranial atherosclerosis in rats

Introduction: Intracranial atherosclerotic stenosis (ICAS) is one of the most common causes of stroke worldwide and, in particular, has been implicated as a leading cause of recurrent ischemic stroke. We developed a new rat model to study intracranial atherosclerosis.

Methods: Twelve-week-old male Sprague-Dawley rats were divided into a control (on a maintain diet) and a high-cholesterol group (on a daily 1% cholesterol diet) for up to 6 weeks. During the first two weeks, NG-nitro-L-arginine methylester (L-NAME, 3 mg/mL) was added to the drinking water in the high-cholesterol group to induce intimal changes making the rats susceptible to atherosclerosis. Blood lipids, including low-density lipoprotein (LDL), cholesterol (CHO), triglycerides (TG), and high-density lipoprotein (HDL), were measured after 3 and 6 weeks. Histological sections of the brains, including internal carotid artery (ICA), middle cerebral artery (MCA), and basilar artery (BA), were prepared to study intracranial artery morphometry and intimal thickening. The levels of CD68, an inflammatory marker, within the vessel walls as determined by immunohistochemistry were also measured.

Results: The high-cholesterol diet increased the levels of classic blood markers of atherosclerosis, LDL, CHO, and TG as well as decreased HDL, which became progressively more intensive with time. Rats showed increased intimal thickening in the ICA, MCA, and BA. This protocol also increased the levels of CD68 immunoreactivity within the vessel walls.

Conclusions: A rat model of intracranial atherosclerosis was effectively developed by high-cholesterol diet and L-NAME administration. This clinically relevant model would be beneficial for studying ICAS.     

A multimodal diagnostic approach for lateralised rhythmic delta activity in the ictal‐interictal continuum∗

The ictal‐interictal continuum represents a diagnostic challenge even for expert neurrophysiologists, often requiring an additional multimodal diagnostic workup to understand its clinical significance. Lateralised rhythmic delta activity (LRDA) is an ictal‐interictal continuum pattern that has only recently been investigated and recognised as potentially ictogenic or sometimes even ictal. We describe a patient who presented with acute‐onset aphasia, initially suspected of having a stroke; advanced brain imaging with CT‐perfusion showed features suggesting regional left temporo‐parietal hyperperfusion and an EEG revealed LRDA with fluctuations and intermixed sharp waves in the same areas. Treatment with lacosamide caused both clinical and EEG improvement after a few hours, supporting the hypothesis that the EEG pattern represented an ictal/interictal phenomenon. In the literature, a correlation between metabolic/perfusion imaging and ictal‐interictal continuum patterns is described regarding lateralised periodic discharges but less studied for LRDA. In this case, we adopted a multimodal approach, integrating advanced imaging, EEG, clinical features, and response to therapy, to consider the overall clinical presentation as focal NCSE.     

Developmental profile of glutamine synthetase in lines of mice bred for ethanol sensitivity

Glutamine synthetase (GS) activity was used as a marker to examine differences in astrocyte development in mice selectively bred for ethanol sensitivity: long sleep (LS), short sleep (SS), mild ethanol withdrawal (MEW), severe ethanol withdrawal (SEW) and control ethanol withdrawal (CEW). We found that 1) GS activity in MEW and SEW was higher than in LS and SS during the first 2 weeks of postnatal development, in the forebrain but not in the cerebellum; 2) lower GS activity was observed consistently in all areas examined with the SS mice as compared to the LS; 3) glutamine synthetase activity in MEW and SEW differed significantly from their controls (CEW) during the early developmental period regardless of the brain region examined; however, after 30 days of maturation, GS activity in SEW was higher than that in MEW and CEW in the forebrain. Astrocytes are known to contribute in the regulation of the neuronal microenvironment. Therefore, we interpret the differences we found in astrocytic function during early brain development among these lines of mice to account in part for the neuronal predisposition to ethanol sensitivity.     

Interaction between manganese and GSTP1 in relation to autism spectrum disorder while controlling for exposure to mixture of lead,mercury, arsenic,and cadmium

BackgroundWe previously reported a significant interactive association between polymorphisms of GSTP1 and blood manganese concentrations (BMC) with autism spectrum disorder (ASD) in Jamaican children. In this paper, we investigate the same interactive association with ASD while adjusting for the mixture of four metals (lead, mercury, cadmium, and arsenic).MethodWe used data from 163 case-control pairs of children 2–8 years of age from our autism project in Jamaica, in which we collected blood for heavy metals analysis at enrollment. To minimize potential multicollinearity between concentrations of the four metals, we generated a mixture index using generalized weighted quantile sum regression, which was used in conditional logistic regression models to control for the four metals while assessing the interactive association between GSTP1 and BMC with ASD.ResultsSimilar to the findings we reported previously, we found that in co-dominant and dominant models for GSTP1, among children with the Ile/Ile genotype, those with BMC ≥ 12 μg/L had 4.6 and 4.27 times higher odds of ASD compared to those with BMC < 12 μg/L (adjusted Matched Odds Ratio (MOR) = 4.6, 95% CI: 1.21–17.42 and adjusted MOR = 4.27, 95% CI: 1.15–15.85, respectively). In the co-dominant model, for children with the Ile/Val and Val/Val genotypes, the adjusted MORs were 1.26 (95% CI: 0.32, 5.01) and 0.26 (95% CI: 0.05, 1.42), respectively.ConclusionsAfter adjusting for the mixture of four metals, the interactive association of BMC and GSTP1 with ASD remained significant with similar magnitude of associations. Results should be interpreted cautiously.     

Striatal dopamine transporter binding for predicting the development of delayed neuropsychological sequelae in suicide attempters by carbon monoxide poisoning: A SPECT study

Carbon monoxide poisoning (COP) after charcoal burning results in delayed neuropsychological sequelae (DNS), which show clinical resemblance to Parkinson's disease, without adequate predictors at present. This study examined the role of dopamine transporter (DAT) binding for the prediction of DNS. Twenty-seven suicide attempters with COP were recruited. Seven of them developed DNS, while the remainder did not. The striatal DAT binding was measured by single photon emission computed tomography with ^99mTc-TRODAT. The specific uptake ratio was derived based on a ratio equilibrium model. Using a logistic regression model, multiple clinical variables were examined as potential predictors for DNS. COP patients with DNS had a lower binding on left striatal DAT binding than patients without DNS. Logistic regression analysis showed that a combination of initial loss of consciousness and lower left striatal DAT binding predicted the development of DNS. Our data indicate that the left striatal DAT binding could help to predict the development of DNS. This finding not only demonstrates the feasibility of brain imaging techniques for predicting the development of DNS but will also help clinicians to improve the quality of care for COP patients.