Yanchun Deng

Expression and prognostic value of NDRG2 in human astrocytomas

OBJECTIVE The pathological grading system of human astrocytoma is usually used to evaluate the outcomes of brain glioma patients. However, it is true that some astrocytoma patients with similar grades underwent obvious discrepancy in survival. Increasing evidence shows that certain tumor biomarkers are more suitable for prognosis assessment of tumors than the grading system. NDRG2, a member of the N-myc downstream-regulated gene family, plays an important role in cell proliferation and differentiation, but whether it can be used as a biomarker for prognosis assessment of astrocytomas remains unknown. METHODS Immunohistochemistry and semi-quantitative RT-PCR were performed to examine the expression profile of NDRG2 in human astrocytoma specimens. Spearman correlation coefficient was used to describe the association between NDRG2 expression and the clinical parameters of astrocytoma patients. RESULTS Our results showed that both protein and mRNA expression levels of NDRG2 were significantly downregulated in astrocytomas. In the analysis of the relationship of NDRG2 expression with pathological grades of astrocytoma and with patient survival rate, we found that NDRG2 expression was negatively correlated with pathological grading but positively with the life span of astrocytoma patients. CONCLUSION NDRG2 can serve as a potential prognostic biomarker for human astrocytoma.

Bilateral medial medullary infarction presenting as Guillain–Barré-like syndrome

Bilateral medial medullary infarction (MMI) is a very rare occurence characterized by acute-onset or progressive quadriplegia, ingual paresis and impaired deep sensation [1]. The disease is requently misdiagnosed at acute stage since the presenting sympoms are similar with other neurological diseases. We describe wo cases having weakness in the limbs with involvement of bular nerve-innervated muscles and respiratory muscles. They were nitially diagnosed as having Guillain–Barre syndrome (GBS). Subequent clinical and imaging features supported the diagnosis of ilateral MMI. The clinical features and differential diagnosis of ilateral MMI will be discussed in this report.

Levetiracetam-associated aggravation of myoclonic seizure in children

Some antiepileptic drugs (AEDs) have been reported to aggravate generalized seizures. We have seen three children whose myoclonic seizures increased on starting treatment with Levetiracetam. In all seizures aggravation was temporally associated to the introduction of the drug. All became seizure-free on withdrawal of levetiracetam with a switch to an alternative antiepileptic drug and this persisted for at least 6 months. This suggests that some children with myoclonic seizures may have an aggravation on starting treatment with levetiracetam but this requires further studies.

The characteristics and related influencing factors of ambulatory EEGs in patients seizure-free for 3—5 years

OBJECTIVE Epileptic patients have a higher relapse risk when EEGs before the initiation of anti-epileptic drug (AED) withdrawal show epileptiform activity. The purpose of this study is to assess the characteristics of ambulatory EEGs before the decision to withdraw AEDs and to clarify potential influencing factors for abnormal EEGs. METHODS 214 epileptic patients were included in the study. These patients were seizure-free for 3-5 years on AED medication. Ambulatory 24-h EEGs were performed before the decision to withdraw AEDs. The demographical data and clinical information of the patients were used for the analysis of influencing factors for EEG findings. RESULTS Ambulatory EEGs showed abnormalities in 41.1% of the patients (88/214). Of 88 patients with abnormal EEGs, 43 had unequivocal epileptic discharges; and 45 only had nonspecific EEG abnormalities. In our analysis, the potential factors for abnormal EEGs included female, delayed therapy, longer duration of intractability/treatment response time and medications failed. CONCLUSIONS In many patients ambulatory EEGs remain abnormal even after seizure-free for 3-5 years; and many factors influenced the characteristics of the EEGs. The findings can assist in establishment of therapeutic principles.

Postnatal expression and denervation induced up-regulation of aquaporin-5 protein in rat sweat gland.

The evolution of aquaporin-5 (AQP5) expression during postnatal development has not been defined in the sweat gland. Previous studies have suggested that AQP isoforms in several peripheral targets are regulated by a neural mechanism. We have examined, in rat sweat glands, the expression of AQP5 during postnatal development and the effects of denervation on AQP5 expression. Both AQP5 mRNA and protein begin to be expressed at postnatal day 10, before sweat-secretory responsiveness first appears; this expression coincides with the occurrence of vasoactive intestinal peptide (VIP) immunoreactivity. Early noradrenergic and later cholinergic interaction between sweat glands and their innervation are disrupted by neonatal chemical sympathectomy or postnatal severance of the sciatic nerve. Examination of such denervated developing rats has shown that secretory responsiveness fails to arise later in the adults, and AQP5 immunostaining increases in the denervated glands, whereas gland morphogenesis and the occurrence of AQP5 expression proceed normally. Immunobloting has revealed an increase of AQP5 abundance after the denervated mature glands lose their secretory ability. These findings suggest that AQP5 protein is necessary for sweat secretion, and that the expression of AQP5 in rat sweat glands is independent of sympathetic innervation. Our data also indicate that factor(s) regulating the normal morphological development of sweat gland might be responsible for controlling AQP5 expression.