Yunqian Li

Retrospective analysis of 14 cases of remote epidural hematoma as a postoperative complication after intracranial tumor resection

BackgroundThe occurrence of remote epidural hematoma as a postoperative complication after intracranial tumor resection is rare. This study reviewed experiences treating these hematomas and speculated on the causes of this disease. This study reviewed the treatment experience of 14 such cases.MethodsThe 14 patients included 10 males and 4 females, with an age range of 19 to 65xa0years old. Six cases of tumors occurred in the sellar region, two cases in the lateral ventricle, one case in the fourth ventricle, one case in a cerebellar hemisphere, and four cases in other sites. Among them, five cases were complicated with supratentorial hydrocephalus. The tumors included five cases of meningioma tumors, two cases of pituitary adenomas, three cases of ependymomas, two cases of craniopharyngiomas, one case of astrocytoma, and one case of tuberculosis tumor. For the cases complicated with hydrocephalus, ventricular drainage was provided if needed, and the tumor resection was then performed, with close observation for postoperative changes. If neurological symptoms and disturbance of consciousness occurred, computed tomography (CT) examination was immediately performed. If a remote epidural hematoma was found, the hematoma was evacuated by craniotomy. The patients were followed up after surgery. In the five cases complicated with hydrocephalus, ventricular drainage was first provided for three cases.ResultsAll of the 14 cases underwent total tumor resection, and postoperative remote epidural hematoma occurred in all cases, including eight cases on the ipsilateral side and adjacent to the supratentorial operative field; two cases occurred on the contralateral side; two cases occurred on bilateral sides; and two cases occurred in distant areas (with infratentorial surgery, the hematoma occurred on the supratentorial area). Postoperative remote epidural hematoma usually occurred 0.5–5xa0h after the tumor resection, when the tentorial hernia had already occurred. Following tumor resection and epidural hematoma evacuation, 13 patients were discharged with good recovery, and one patient died.ConclusionsThe reduced intracranial pressure due to the intracranial tumor resection may be the cause of this hematoma. This type of epidural hematoma is acute and often occurs before hernia. Thus, the risk of remote epidural hematoma after intracranial tumor resection needs to be made known. Aggressive hematoma evacuation can often result in satisfactory outcomes for patients.

Temozolomide in combination with metformin act synergistically to inhibit proliferation and expansion of glioma stem-like cells

Glioblastoma is the most common and most aggressive brain tumor in adults. The introduction of temozolomide (TMZ) has advanced chemotherapy for malignant gliomas, but it is not curative. The difficulties in treating glioblastoma may be as a result of the presence of glioma stem cells (GSCs), which are a source of relapse and chemoresistance. Another reason may be that endogenous Akt kinase activity may be activated in response to clinically relevant concentrations of TMZ. Akt activation is correlated with the increased tumorigenicity, invasiveness and stemness of cancer cells and overexpression of an active form of Akt increases glioma cell resistance to TMZ. Mounting evidence has demonstrated that cancer stem cells are preferentially sensitive to an inhibitor of Akt and down-regulation of the PI3K/Akt pathway may enhance the cytotoxicity of TMZ. Metformin (MET), the first-line drug for treating diabetes, it has been proved that it reduces AKT activation and selectively kills cancer stem cells, but whether it can potentiate the cytotoxicity of TMZ for GSCs remains unknown. In the present study, the GSCs isolated from human glioma cell line U87 and Rat glioma cell line C6, in vitro treatment with TMZ either alone or with MET. The present study demonstrates that MET acts synergistically with TMZ in inhibiting GSCs proliferation and generating the highest apoptotic rates when compared to either drug alone. These findings implicate that GSCs cytotoxicity mediated by TMZ may be stimulated by MET, have a synergistic effect, but the definite mechanisms remain elusive.

Use of 3D-computed tomography angiography for planning the surgical removal of pineal region meningiomas using Poppen's approach: a report of ten cases and a literature review

BackgroundThere are several treatment approaches for pineal region meningiomas, such as Poppens approach, Krauses approach and combinations of the two approaches. We present our experience with the use of 3D-computed tomography angiography for planning the surgical removal of pineal region meningiomas using a suboccipital transtentorial approach (Poppens approach) and evaluate the role of Poppens approach.MethodsDuring the period from January 2005 to June 2010, ten patients presented to us with pineal region meningioma. MRI was routinely used to define the tumor size, position, and its relevant complications while 3D-CTA was applied to define the blood supply of the tumor and the venous complex (VC) shift before operations. Most of the meningiomas had developed at both sides of the tentorial plane and extended laterally with typical characteristics of a pineal region tumor.ResultsAll tumors were completely removed surgically without any injury to the VC. Postoperative intracranial infection occurred in one case who recovered after antibiotics were given. Postoperative intraventricular hemorrhage and pneumocephalus were found in one case, but fully recovered after conservative treatment. In the nine cases of concurrent hydrocephalus, this was gradually relieved in eight patients and the single case that became aggravated was successfully treated with ventriculoperitoneal shunt. Moreover, the follow-up MRI examinations did not indicate any recurrence of the meningiomas.ConclusionWe found that the use of Poppens approach is strongly supported for the successful removal of pineal region meningiomas without serious complications.

Calcification of vestibular schwannoma: a case report and literature review

Calcification rarely occurs in vestibular schwannoma (VS), and only seven cases of calcified VS have been reported in the literature. Here, we report a 48-year-old man with VS, who had a history of progressive left-sided hearing loss for 3 years. Neurological examination revealed that he had left-sided hearing loss and left cerebellar ataxia. Magnetic resonance imaging and computerized tomography angiography showed a mass with calcification in the left cerebellopontine angle (CPA). The tumor was successfully removed via suboccipital craniotomy, and postoperative histopathology showed that the tumor was a schwannoma. We reviewed seven cases of calcified VS that were previously reported in the literature, and we analyzed and summarized the characteristics of these tumors, including the calcification, texture, and blood supply. We conclude that calcification in VS is associated with its texture and blood supply, and these characteristics affect the surgical removal of the tumor.

Knockdown of long non‐coding RNA ANRIL inhibits proliferation, migration, and invasion but promotes apoptosis of human glioma cells by upregulation of miR‐34a

Gliomas are the most common types of primary central nervous system malignancy found in adults. Long non‐coding RNA antisense non‐coding RNA in the INK4 locus (ANRIL) variants are associated with glioma and miR‐34a is markedly downregulated in U251 glioma cells. The 3′‐untranslated region (3′UTR) of silent information regulator 1 (Sirt1) contains a conserved site that is targeted directly by miR‐34a. Therefore, in this study, we investigated the roles of ANRIL, miR‐34a, and Sirt1 in glioma and their potential interactions. Firstly, expression of ANRIL in normal glia cells and five glioma cell lines was measured. Then, effects of ANRIL suppression on cell proliferation, apoptosis, migration and invasion of U251 cells as well as expression of miR‐34a were assessed. Meanwhile, effects of miR‐34a on U251 cells silencing ANRIL were tested. Whether Sirt1 is a target of miR‐34a was verified, followed by estimating the role of Sirt1 overexpression in U251 cells overexpressing miR‐34a. Finally, the involved signaling pathways were assessed. ANRIL was upregulated in glioma cells and its suppression inhibited cell proliferation, migration and invasion but promoted cell apoptosis. ANRIL acted as a sponge of miR‐34a, and Sirt1 is a target of miR‐34a. Then, Sirt1 was proved to function through activation of the PI3K/AKT and mTOR signaling pathways. In conclusion, ANRIL was upregulated in glioma, and its inhibition could repress cell proliferation, migration and invasion but inhibit cell apoptosis through miR‐34a‐mediated downregulation of Sirt1, involving the inactivation of the PI3K/AKT and mTOR pathways.

Identification of polymorphisms and transcriptional activity of the proto-oncogene KIT located on both autosomal and B chromosomes of the Chinese raccoon dog

B chromosomes are dispensable and co-exist with autosomal and sex chromosomes. The karyotype of the Chinese raccoon dog (Nyctereutes procyonoides procyonoides) comprises 0-4 B chromosomes. The proto-oncogene KIT is found on all B chromosomes of the Chinese raccoon dog. In the present study, partial DNA and mRNA sequences of KIT were amplified and sequenced from four individuals containing B chromosomes. Sequence analyses revealed that polymorphisms including single nucleotide polymorphisms (SNPs) and inserts/deletions were rich in the KIT gene of Chinese raccoon dog at the genomic level. However, no polymorphism was detected at the mRNA level. A comparison of mRNA sequences from Chinese raccoon dogs with the corresponding sequences derived from arctic fox and dog, which do not contain B chromosomes, revealed the mRNA sequences of the 10 SNPs to be identical between these three species. Therefore, these findings suggest that KIT located on the B chromosomes in Chinese raccoon dog lacks transcriptional activity.

Identification of cDNA sequences and alternative splicing patterns of canine AMEL genes (AMELX and AMELY).

Amelogenin is a major protein of the developing enamel matrix. There are two amelogenin genes (AMELX and AMELY) located on the X and Y chromosomes, respectively, in dogs. In the present study, we characterized full-length cDNAs and alternative splicing patterns of the AMEL genes in the tooth tissue of a dog by 5- and 3-rapid amplification of cDNA ends and AMEL-specific RT-PCR. Sequence analysis revealed that the coding regions of AMELX and AMELY were 579 and 576 bp (accession Nos. KP244310 and KP244311), respectively. The coding sequence of AMELX had 95.1% identity to that of AMELY. The AMEL genes on X and Y chromosomes were both expressed in developing tooth tissue. Eight different alternatively spliced transcripts were identified, five from AMELX and three from AMELY.

Newcastle disease virus enhances the growth-inhibiting and proapoptotic effects of temozolomide on glioblastoma cells in vitro and in vivo

Glioblastoma (GBM) is the most serious and most common brain tumor in humans. Despite recent advances in the diagnosis of GBM and the development of new treatments, the prognosis of patients has not improved. Multidrug resistance, particularly resistance to temozolomide (TMZ), is a challenge in combating glioma, and more effective therapies are needed. Complementary treatment with the LaSota strain of the naturally oncolytic Newcastle disease virus (NDV-LaSota) is an innovation. In our experiments, the combination therapy of NDV-LaSota and temozolomide (TMZ) was more effective than either treatment alone in inducing apoptosis in glioma cells. NDV can function as a tumor cell selective approach to inhibit AKT and activate AMPK. Consequently, mTOR, 4EBP1 and S6K were also suppressed. The combination therapy of NDV and TMZ also significantly extended survival in a rat xenograft tumor model. In conclusion, NDV suppress AKT signaling and enhances antitumor effects of TMZ. Our study provides one of the theoretical basis for the use of a combined therapy of TMZ and NDV, which could benefit GBM patients.

Isolation and characterization of polymorphic microsatellite markers for blue fox (Alopex lagopus).

The blue fox, belonging to the family Canidae, is a coat color variant of the native arctic fox (Alopex lagopus). To date, microsatellite loci in blue fox are typically amplified using canine simple sequence repeat primers. In the present study, we constructed an (AC)n enrichment library, and isolated and identified 17 polymorphic microsatellite markers for blue fox. The number of alleles per locus is from two to seven based on 24 examined individuals. The expected and observed heterozygosities were in the range of 0.3112 to 0.8236 and 0.2917 to 0.8750, respectively. The polymorphic information content per locus ranged from 0.2583 to 0.8022. These polymorphic markers can be useful for future population genetic studies of both farmed blue foxes and wild arctic foxes.

De novo assembly and characterization of farmed blue fox (Alopex lagopus) global transcriptome using Illumina paired-end sequencing.

The blue fox (Alopex lagopus), a coat-color variant of the Arctic fox, is a domesticated fur-bearing mammal. In the present study, transcriptome data generated from a pool of nine different tissues were obtained with Illumina HiSeq2500 paired-end sequencing technology. After filtering from raw reads, 32,358,290 clean reads were assembled into 161,269 transcripts and 97,252 unigenes by the Trinity fragment assembly software. Of the assembled unigenes, 37,967 were annotated in the National Center for Biotechnology Information (NCBI) Non-Redundant (NR) protein database and 26,264 in the Swiss-Prot database. Among the annotated unigenes, 24,839 and 24,267 were assigned using the Gene Ontology (GO) and euKaryotic Orthologous Groups (KOG) databases, respectively. Altogether, 17,057 unigenes were mapped onto 227 pathways using the Kyoto Encyclopedia of Genes and Genomes database. In addition, 6394 simple sequence repeats were identified by examining 12,965 unigenes (>1 kb), which could contribute to the development of molecular markers. This study generated transcriptome data for the blue fox that will promote further progress in expression profiling studies, and provide a good annotation basis for genomic studies.