Silicon-Organic Hybrid Electro-Optic Modulator and Microwave Photonics Signal Processing Applications.

Electro-optic modulator (EOM) is one of the key devices of high-speed optical fiber communication systems and ultra-wideband microwave photonic systems. Silicon-organic hybrid (SOH) integration platform combines the advantages of silicon photonics and organic materials, providing a high electro-optic effect and compact structure for photonic integrated devices. In this paper, we present an SOH-integrated EOM with comprehensive investigation of EOM structure design, silicon waveguide fabrication with Slot structure, on-chip poling of organic electro-optic material, and characterization of EO modulation response. The SOH-integrated EOM is measured with 3 dB bandwidth of over 50 GHz and half-wave voltage length product of 0.26 V·cm. Furthermore, we demonstrate a microwave photonics phase shifter by using the fabricated SOH-integrated dual parallel Mach-Zehnder modulator. The phase shift range of 410° is completed from 8 GHz to 26 GHz with a power consumption of less than 38 mW.

[Retracted] Inhibition of δ­opioid receptors induces brain glioma cell apoptosis through the mitochondrial and protein kinase C pathways.

[This retracts the article DOI: 10.3892/ol.2013.1546.].

Multiband Signal Receiver by Using an Optical Bandpass Filter Integrated with a Photodetector on a Chip.

Photonic integration brings the promise of significant cost, power and space savings and propels the real applications of microwave photonic technology. In this paper, a multiband radio frequency (RF) signal simultaneous receiver using an optical bandpass filter (OBPF) integrated with a photodetector (PD) on a chip is proposed, which was experimentally demonstrated. The OBPF was composed of ring-assisted Mach-Zehnder interferometer with a periodical bandpass response featuring a box-like spectral shape. The OBPF was connected to a PD and then integrated onto a single silicon photonic chip. Phase-modulated multiband RF signals transmitted from different locations were inputted into the OBPF, by which one RF sideband was filtered out and the phase modulation to intensity modulation conversion was realized. The single sideband with carrier signals were then simultaneously detected by the PD. A proof-of-concept experiment with the silicon photonic integrated chip was implemented to simultaneously receive four channels of 8 GHz, 12 GHz, 14 GHz and 18 GHz in the X- and Ku-bands. The performance of the integrated microwave photonic multiband receiver-including the receiving sensitivity, the spurious free dynamic range, the gain and the noise figure across the whole operation frequency band-was characterized in detail.

Drug therapy for chronic subdural hematoma: Bench to bedside.

Chronic subdural hematoma (CSDH) is a common neurosurgical condition. Currently, surgery is the most effective medical intervention for treatment of this disorder. Because CSDH is an inflammatory angiogenic disease involving multifactorial mechanisms, a better understanding of CSDH pathogenesis should facilitate clinical management. Therefore, the purpose of this review is to describe recent progress in elucidation of molecular mechanisms causing CSDH and to summarize the body of knowledge gained from past drug treatment studies. Because hematoma fluid and outer membrane characteristics may be linked to pathology, they could serve as disease biomarkers. Moreover, past drug treatment studies have shown that such biomarkers may mutually synergize to initiate and promote CSDH progression. These findings suggest that modulation of biomarker expression or function using drug therapy may benefit CSDH patients.

Novel type of peritoneocentesis trocar-assisted distal ventriculoperitoneal shunt placement with supervision via a one-port laparoscope.

Ventriculoperitoneal shunts (VPS) are the primary treatment for hydrocephalus and are associated with a high risk of complications, specifically in patients who are obese or have abdominal adhesions or shunt revisions. The present study describes the use of a novel type of peritoneal catheter peritoneocentesis trocar insertion with the assistance of a one-port laparoscope. A total of 36 patients with hydrocephalus underwent this novel type of peritoneocentesis trocar-assisted VPS. The distal shunt catheter was placed into the right subdiaphragmatic space and the catheter was traversed through a single hole drilled through the liver falciform ligament. The duration of the laparoscopic surgery ranged from 6-18 min (mean 10.4±1.6 min). No shunt-related infections or catheter malfunctions or injuries to the intra-abdominal organs occurred. The total abdominal incision length was 1.0 cm (0.5+0.5 cm). No laparoscopy-related complications were observed during follow-up assessments. The novel approach used in the current study is very easy to perform, and this method may significantly reduce the risk of malfunction complications. The presented method also has the advantages of reduced trauma and a simpler surgery. The current study indicated that this simple, minimally invasive procedure was beneficial for patients with hydrocephalus, specifically in cases of patients with obesity, peritoneal adhesions or shunt revisions.

Malignant Cerebral Swelling After Cranioplasty due to Ipsilateral Intracranial Vasculopathy: Case Report and Literature Review.

BACKGROUND: Cranioplasty is a well-established surgical operation that is used worldwide for patients with skull defects following decompressive craniectomy (DC). However, in some cases, potentially fatal complications may occur, such as malignant cerebral swelling after uneventful cranioplasty. CASE DESCRIPTION: We present a rare case of massive malignant ipsilateral cerebral swelling following uneventful titanium mesh cranioplasty due to rare ipsilateral intracranial vasculopathy confirmed by magnetic resonance angiography (MRA) and magnetic resonance venography (MRV). Fortunately, we performed titanium mesh explantation and extended DC in time, and the patient survived. Malignant cerebral swelling after uneventful cranioplasty is an unpredictable but fatal complication. Most reported cases have had an unfavorable prognosis. To the best of our knowledge, the mechanism was first confirmed by MRA and MRV, which demonstrated that the cerebral swelling was due to unilateral intracranial vasculopathy, including a rare ipsilateral intracranial internal carotid artery occlusion, as well as extremely thin lateral and sigmoid sinuses. CONCLUSIONS: Our case demonstrates for the first time that ipsilateral intracranial vasculopathy is a risk factor for malignant cerebral swelling after cranioplasty. Patients with traumatic brain injury with suspected intracranial vasculopathy should undergo a comprehensive vascular evaluation before cranioplasty to help prevent malignant cerebral swelling.

Partial titanium mesh explantation cured post-cranioplasty implant-associated scalp infection.

Titanium mesh cranioplasty is routinely used worldwide for skull defect patients given its advantages, such as stability and biocompatibility. However, there are very few reports concerning the treatment of implant-associated scalp infection, which is one of the most common complications. The aim of the study is to retrospectively evaluate a novel operation technique for the treatment of titanium mesh-associated scalp infection post-cranioplasty, namely partial titanium mesh explantation (PTME). A retrospective study was conducted in all patients who underwent surgical treatment for implant-associated scalp infection from January 2012 to September 2016 in our hospital. In total, 17 patients were selected for study analysis among 231 patients who underwent cranioplasty. The treatment success rate of PTME was 85.7%. There was no statistically significant difference in demographics and characteristics except for follow-up length of time between the PTME group and TTME (total titanium mesh explantation) group (Non-paired Student's t-test, P=0.037). While, The PTME group exhibited a significantly reduced skull defect area post-operation compared with the TTME group (Non-paired Student's t-test, P=0.002). Moreover, post-PTME skull area also exhibited a significantly reduced skull defect area compared with the pre-cranioplasty area in the same patient (Non-paired Student's t-test, P=0.006). Compared with traditional surgical treatment of implant-associated scalp infection, PTME combined with strict debridement and antibiotic therapy can cure implant-associated scalp infection. Moreover, PTME could preserve sufficient titanium mesh for brain protection and cosmesis.

MicroRNA-141 inhibits glioma cells growth and metastasis by targeting TGF-ß2.

MicroRNA-141 (miR-141) has been reported to function as tumor suppressor in many types of cancer. However, the molecular function and underlying mechanisms of miR-141 in glioma is still unknown. The aims of this study were to investigate miR-141 expression and determine its biological function and underlying mechanism in glioma. In this study, we found that miR-141 expression levels, both in glioma cell lines and in tissues, were significantly lower than that in a normal human astrocyte cell line or adjacent non-cancerous tissues. Overexpression of miR-141 significantly inhibited glioma cell proliferation, colony formation, migration and invasion in vitro, as well as suppressed glioma tumor growth in vivo. In addition, transforming growth factor beta 2 (TGF-ß2) was identified as a target of miR-141 in glioma cells. TGF-ß2 expression was also found to be upregulated, and negatively associated with miR-141 in glioma tissues. TGF-ß2 over-expression partly reversed the effect caused by transfection of miR-141 mimic. These findings together suggested that miR-141 functioned as tumor suppressor by targeting TGF-ß2, and that miR-141 might be a promising therapeutic strategy for future treatment of glioma.

Lung-protective Ventilation in Patients with Brain Injury: A Multicenter Cross-sectional Study and Questionnaire Survey in China.

BACKGROUND: Over the years, the mechanical ventilation (MV) strategy has changed worldwide. The aim of the present study was to describe the ventilation practices, particularly lung-protective ventilation (LPV), among brain-injured patients in China. METHODS: This study was a multicenter, 1-day, cross-sectional study in 47 Intensive Care Units (ICUs) across China. Mechanically ventilated patients (18 years and older) with brain injury in a participating ICU during the time of the study, including traumatic brain injury, stroke, postoperation with intracranial tumor, hypoxic-ischemic encephalopathy, intracranial infection, and idiopathic epilepsy, were enrolled. Demographic data, primary diagnoses, indications for MV, MV modes and settings, and prognoses on the 60th day were collected. Multivariable logistic analysis was used to assess factors that might affect the use of LPV. RESULTS: A total of 104 patients were enrolled in the present study, 87 (83.7%) of whom were identified with severe brain injury based on a Glasgow Coma Scale ≤8 points. Synchronized intermittent mandatory ventilation (SIMV) was the most frequent ventilator mode, accounting for 46.2% of the entire cohort. The median tidal volume was set to 8.0 ml/kg (interquartile range [IQR], 7.0-8.9 ml/kg) of the predicted body weight; 50 (48.1%) patients received LPV. The median positive end-expiratory pressure (PEEP) was set to 5 cmH2O (IQR, 5-6 cmH2O). No PEEP values were higher than 10 cmH2O. Compared with partially mandatory ventilation, supportive and spontaneous ventilation practices were associated with LPV. There were no significant differences in mortality and MV duration between patients subjected to LPV and those were not. CONCLUSIONS: Among brain-injured patients in China, SIMV was the most frequent ventilation mode. Nearly one-half of the brain-injured patients received LPV. Patients under supportive and spontaneous ventilation were more likely to receive LPV. TRIAL REGISTRATION: ClinicalTrials.org NCT02517073 https://clinicaltrials.gov/ct2/show/NCT02517073.

Inhibition of δ-opioid receptors induces brain glioma cell apoptosis through the mitochondrial and protein kinase C pathways.

Brain glioma is a malignant tumor with a high incidence rate and poor prognosis that has become a focus of studies of central nervous system diseases. Previous studies have suggested that δ-opioid receptors may affect the proliferation and apoptosis of numerous types of tumor cells. However, to date, their precise mechanism(s) of action have not been elucidated. The present study aimed to investigate the effects of inhibiting δ-opioid receptors in brain glioma cell proliferation and apoptosis and their relevant molecular mechanisms. Various doses of naltrindole were supplied to treat brain glioma cells using the MTT method to assess the proliferation index. Flow cytometry was used to investigate the changes in cell apoptosis and mitochondrial membrane potential. The expression levels of Bax, Bcl-2, Bcl-xL, cytochrome c, caspase-9, caspase-3 and protein kinase C (PKC) were measured using western blotting. Naltrindole was observed to inhibit brain glioma cell proliferation and promote apoptosis in a dose- and time-dependent manner. Furthermore, the addition of naltrindole lead to changes in the brain glioma cell membrane potential and regulated Bax translocation to the mitochondrial membrane, consequently promoting the release of cytochrome c into the cytoplasm, followed by the activation of caspase-9 and -3, which caused cell apoptosis. In addition, naltrindole was able to regulate the expression levels of the cellular internal phosphorylated PKC proteins, which are closely associated with the inhibition of cell proliferation. In conclusion, the inhibition of δ-opioid receptors may inhibit brain glioma cell proliferation and lead to apoptosis, which is closely associated with the mitochondrial and PKC pathways.

Involvement of post-transcriptional regulation of FOXO1 by HuR in 5-FU-induced apoptosis in breast cancer cells.

The post-transcriptional control of specific mRNAs is a widespread mechanism of gene regulation, which contributes to numerous biological processes in a number of cell types. The Forkhead box O (FoxO) transcription factor FOXO1 is an important tumor suppressor involved in apoptosis, the cell cycle, DNA damage repair and oxidative stress. Bioinformatic prediction identified that the 3' untranslated region (UTR) of FOXO1 is enriched with binding motifs for the human ELAV/Hu protein (HuR), indicating that FOXO1 is a potential target of HuR. Luciferase reporter assays demonstrate that HuR specifically regulates FOXO1 expression through AU-rich elements (AREs) within the FOXO1 3' UTR. Immunoprecipitation studies confirmed that HuR associates with FOXO1 mRNA in MDA-MB-231 breast cancer cells and that HuR upregulates FOXO1 mRNA levels through increased mRNA stability. Using a HuR loss- and gain-of-function approach, we revealed that FOXO1 expression was correspondingly decreased or increased in MDA-MB-231 cells. Functional assays demonstrated that HuR and FOXO1 expression levels were markedly enhanced upon 5-fluorouracil (5-FU) stimulation in MDA-MB-231 cells. Knockdown of HuR apparently abrogated 5-FU-induced apoptosis detected by caspase-3 activities. Furthermore, in HuR knockdown cells, additional overexpression of FOXO1 moderately recovered 5-FU-induced apoptosis, which verified that HuR-modulated apoptosis upon 5-FU treatment was partially mediated by its post-transcriptional regulation of FOXO1. Therefore, modulating FOXO1 expression has been suggested to lead to the development of new therapeutic treatments for certain types of cancer.

Transoral penetrating craniocerebral injury by a bamboo chopstick in a child.

We present a 3-year-old girl with a transoral injury by a bamboo chopstick penetrating the middle skull base. The features of imaging are described and the management is discussed. The potential for injury to the cavernous sinus is emphasized, even if no there is no hemorrhage on the initial CT scan. Early intracranial infection in relation to penetrating injuries is a factor in planning treatment by craniotomy.

Distinct genomic aberrations between low-grade and high-grade gliomas of Chinese patients.

BACKGROUND: Glioma is a type of tumor that develops in the central nerve system, mainly the brain. Alterations of genomic sequence and sequence segments (such as copy number variations or CNV and copy neutral loss of heterozygosities or cnLOH) are thought to be a major determinant of the tumor grade. METHODS: We mapped genomic variations between low-grade and high-grade gliomas (LGG and HGG) in Chinese population based on Illumina's Beadchip and validated the results using real-time qPCR. RESULTS: AT THE CYTOBAND LEVEL, WE DISCOVERED: (1) unique losses in LGG on 5q, 8p and 11q, and in HGG on 6q, 11p, 13q and 19q; (2) unique gains in the LGG on 1p and in HGG at 5p, 7p, 7q and 20q; and (3) cnLOH in HGG only on 3q, 8q, 10p, 14q, 15q, 17p, 17q, 18q and 21q. Subsequently, we confirmed well-characterized oncogenes among tumor-related loci (such as EGFR and KIT) and detected novel genes that gained chromosome sequences (such as AASS, HYAL4, NDUFA5 and SPAM1) in both LGG and HGG. In addition, we found gains, losses, and cnLOH in several genes, including VN1R2, VN1R4, and ZNF677, in multiple samples. Mapping grade-associated pathways and their related gene ontology (GO) terms, we classified LGG-associated functions as "arachidonic acid metabolism", "DNA binding" and "regulation of DNA-dependent transcription" and the HGG-associated as "neuroactive ligand-receptor interaction", "neuronal cell body" and "defense response to bacterium". CONCLUSION: LGG and HGG appear to have different molecular signatures in genomic variations and our results provide invaluable information for the diagnosis and treatment of gliomas in patients with variable duration or diverse tumor differentiation.

Anhelation due to formation of tuberculomas at the medulla oblongata during chemotherapy of tuberculous meningitis.

Formation of tuberculoma is a rare response of neurotuberculosis in patients regularly and adequately treated with anti-tuberculous drugs. We report a 13-year-old girl with two tuberculomas which formed in the dorsal part of the medulla oblongata during chemotherapy for tuberculous meningitis. The tuberculomas were both removed via a suboccipital midline approach and were demonstrated by pathological findings but the girl died of cardiac arrest that was thought to be caused by postoperative medulla oblongata oedema. In combination with a literature review, we discuss the clinical features and treatment options of brainstem tuberculomas.

Pilomyxoid astrocytoma in cerebellum.

Pilomyxoid astrocytoma is a new identified variant type of pilocytic astrocytoma, and typically locates in the hypothalamic and chiasmatic region. Herein, we reported a nine-year-old boy with pilomyxoid astrocytoma in the cerebellum. MRI scanning showed a tumor involved the cerebellar vermis, tonsil, the forth ventricle and brainstem. It was homogeneous isointensity on T1WI, relative hyper-intensity on T2WI, hyper-intensity on fluid attenuated inversion recovery (FLAIR) images, and uniform enhancement on contrast T1WI. The tumor was sub-totally removed and was proved histologically to be pilomyxoid astrocytoma. Follow-up at the 5th month, MRI showed the residual tumor enlarged at the brainstem. The patient survived 10 months after the operation, and finally died of respiration failure resulting from brainstem dysfunction.

Two subtypes of meningiomas with different imaging co-existed at sphenoid ridge.

Intracranial multiple meningiomas are not uncommon, but multiple meningiomas consisting of different subtypes are rare. Here, we describe an adult male patient with two meningiomas located at sphenoid ridge, with different features on MRI and CTA. Histological examination revealed that one was fibrous meningioma and the other was psammomatous meningioma.

Diffuse scalp malignant peripheral nerve sheath tumor with intracranial extension in a patient with neurofibromatosis type 1.

We describe a rare scalp malignant peripheral nerve sheath tumor (MPNST) with cranial destruction and intracranial extension in a 52-year-old male with neurofibromatosis type 1 (NF1). The scalp tumor measured 22cm×18cm, with local surface ulceration. Skin examination revealed many café-au-lait spots and small, hard dermal nodules on the trunk. CT scans revealed the scalp tumor to have heterogeneous density with partial destruction of the right parietal cranium; on T1-weighted MRI the scalp tumor displayed heterogeneous hypointensity, whereas on T2-weighted and fluid-attenuated inversion recovery MRI it was hyperintense. The tumor was excised totally and the scalp reconstructed using a skin flap isolated from the lateral aspect of the left thigh. Histological examination confirmed that the tumor was an MPNST. The patient recovered uneventfully and was well at the 6-month follow-up, with no local or other tumor recurrence noted.

Large cystic hypoglossal schwannoma with fluid-fluid level: a case report.

Hypoglossal schwannomas are rare skull base tumors. Furthermore, cystic hypoglossal schwannomas are extremely uncommon. We report the first case of a large cystic hypoglossal schwannoma with a fluid-fluid level. A 36-year-old woman presented with increased intracranial pressure and cerebellar signs without hypoglossal nerve palsy. Magnetic resonance imaging showed a predominantly cystic mass with a fluid-fluid level in the foramen magnum region extending into the hypoglossal canal. The intracranial tumor was largely removed via a midline suboccipital subtonsillar approach, leaving only a tiny residue in the hypoglossal canal. Histology confirmed a schwannoma with relative hypervascularity. Twenty months later, the tumor recurred and presented as a multicystic dumbbell-shaped lesion, extending intra- and extracranially through the enlarged hypoglossal canal. A complete resection of the intracranial and intracanalicular parts of the tumor was achieved with a small extracranial remnant treated by radiosurgery. Histology revealed a focal increased K(i)67 proliferative index. In this report, we discuss the possible reasons for the absence of hypoglossal nerve palsy and the potential mechanism of the formation of the fluid-fluid level, and we consider the treatment of this lesion.

Recurrent epidermoid cyst with malignant transformation into squamous cell carcinoma.

A 50-year-old male presented with a recurrent epidermoid cyst with malignant transformation into squamous cell carcinoma. The patient was first hospitalized for intermittent seizures in 2000. Computed tomography (CT) showed a hypodense lesion with enhanced capsule but no peripheral edema in the right temporal lobe. Craniotomy was performed and the lesion was completely removed. The histological diagnosis was epidermoid cyst. Six years later, the patient experienced blurred vision and hemiparesis in the left extremities. CT showed a hyperdense mass with peripheral edema in the right temporal lobe. Repeat CT 2 months later revealed a larger mass. The recurrent lesion was removed, and the histological diagnosis was squamous cell carcinoma. Intracranial epidermoid cyst is a benign tumor which often appears hypodense on CT, so change to hyperdensity in the recurrent tumor may indicate malignant transformation.